[Clinical significance of stress thallium-201 myocardial scintigraphy for evaluation of right ventricular ischemia]

Although stress thallium (T1)-201 myocardial imaging has been used for evaluation of the ischemic lesion of the left ventricle, there are few reports on the usefulness of this method for the assessment of the right ventricle in ischemic heart disease. The patients (pts) fell into three distinct groups according to the findings of the coronary arteriogram: normal control group (16 cases) without angiographically documented coronary artery disease; non-RCA group (16 cases) with a significant stenosis (greater than or equal to 75% narrowing) in the left coronary artery but free of a significant right coronary artery (RCA) stenosis; RCA group (28 cases) with a significant RCA stenosis regardless of the presence or absence of a significant left coronary artery lesion. After the pts were exercised to 80-85% of the expected maximum heart rate, immediate and delayed (3 to 4 hrs) T1-201 myocardial images were obtained. The images of the right ventricular free wall ( RVFW ) in 30 degrees and 60 degrees left anterior oblique (LAO) projections were evaluated visually with regard to the presence or absence of a defective T1-201 uptake, degree of the radioactivity and redistribution phenomenon of the RVFW . On immediate images, all normal controls and 13 pts in non-RCA group had continuous visualization of the RVFW . In RCA group, the RVFW was not visualized in five and 11 showed defective visualization of the RVFW in the 30 degrees LAO projection. In 60 degrees LAO projection, the RVFW was not visualized in six and five had defective visualization. On delayed images in RCA group, two pts who had no inferior myocardial infarction (MI) had redistribution of T1-201 into the RVFW . Defective visualization of the RVFW on the image was associated with location of the RCA lesion, history of inferior MI and degree of RCA stenosis. Collateral circulation seemed to protect the RVFW against the development of exercise-induced ischemia and affect the occurrence of redistribution of T1-201 into the RVFW . The RVFW findings on images improved the sensitivity for identifying the pts with RCA disease, compared with the LV findings alone. Thus, stress T1-201 myocardial imaging is able to visualize the myocardial blood flow of the RVFW and may provide a useful non-invasive method in the evaluation of right ventricular ischemia.

A new method for quantitative analysis of thallium-201 myocardial image-"corrected" circumferential profile method

A new method for computer-assisted quantitative analysis of a thallium (Tl)-201 myocardial image ("corrected" circumferential profile method) was described. Since the Tl-201 myocardial image of a normal subject is not homogeneous, an attempt was made to correct for this non-homogeneity. Three groups of subjects were studied, including 10 normal volunteers (group A, mean age of 27.5 years), 14 patients with atypical chest pain and normal coronary arteriogram (group B, mean age of 56.7 years) and 16 patients with first transmural myocardial infarction (group C, mean age of 71.0 years). The myocardial images were acquired at rest at anterior, left anterior oblique (30 degrees and 60 degrees) and left lateral projections. With a scintigram, the left ventricle was outlined and divided into 24 radial segments by radii drawn from the center of the left ventricle. Average radioactivity per pixel in normal subjects was obtained in each segment and normalized to the highest segment (= 100%). The ratio of 100% to the mean of normalized radioactivity in percent in each segment from 10 normal volunteers was calculated and designated as a correction factor for each segment. After the correction of average radioactivity per pixel in each segment using this correction factor and after relating it to the highest radioactive segment, the mean (= 100%) and standard deviation (SD) were calculated and (100-4SD)% was defined as the normal lower limit. In the scintigram of groups B and C, "corrected" circumferential profiles were obtained from the regional radioactivity multiplied by the correction factor, normalized to the highest segment (100%) and compared with the lower normal limit. The ratio (%) of the area of patient's circumferential profile curve below the normal limit to the total area below the normal limit was obtained at each view and the sum of them was called the total "corrected" defect score. Infarct size analyzed by the "corrected" circumferential profile method correlated well with that analyzed by visual interpretation, and was useful in differentiating group C from group B.

Semiquantitative histochemical investigation of lysosomal enzyme activities in the aortic endothelial cells of spontaneously hypertensive rats

In order to obtain information about changes in lysosomal enzyme activities in the aortic endothelial cells under hypertensive conditions, semiquantitative histochemical investigations of acid phosphatase (Ac-Pase) and N-acetyl-beta-glucosaminidase (NAGase) activities in the aorta of spontaneously hypertensive rats (SHR) were performed on 'Häutchen' monolayer preparations. The aortic endothelial cells in SHR showed increased Ac-Pase and NAGase activities as compared with those in control normotensive rats, and the activities tended to increase with advancing age. The degenerating process of endothelial cells expressed by lysosomal enzyme activity seems to be accelerated by hypertension. The increased lysosomal enzymes may participate in the further development of hypertensive vascular changes.

Di- and trimannosylceramides in hepatopancreas of a fresh-water bivalve, Hyriopsis schlegelii

An investigation of di- and triglycosylceramides of hepatopancreas of a fresh-water bivalve, Hyriopsis schlegelii, gave the following results: (1) The total amount of neutral glycosphingolipid was 7.2 mg/g of the dry weight of the hepatopancreas. (2) The diglycosylceramide fraction accounted for 4.8% of the total neutral glycolipid, and consisted of Man(beta 1 leads to 2)Man(beta 1 leads to 1)Cer, Man (beta 1 leads to 4)Glc leads to Cer, Gal(beta 1 leads to 4)Glc leads to Cer, and Gal(beta 1 leads to 4)Gal(beta 1 leads to 1)Cer. The presence of so many different types of diglycosylceramides in a single tissue appears to be the exception rather than the rule. (3) The triglycosylceramide fraction amounted to 12.2% of the total neutral glycolipid and contained a mixture of Man(alpha 1 leads to 3)Man(beta 1 leads to 2)Man(beta 1 leads to 1)Cer and Man(alpha 1 leads to 3)Man(beta 1 leads to 4)Glc leads to Cer. (4) The spectrum of di- and triglycosylceramides of the hepatopancreas was more complex than that of spermatozoa of this bivalve. (5) It is an interesting finding that a series of glycolipids containing one to three mannose residues occurs in nature. (6) The ceramide moieties of the above two fractions contained the normal saturated fatty acids in the range of C14-C24, and derivatives of 4-sphingenine. The structural analysis involved (1) gas-liquid chromatography of the component sugars, fatty acids and long-chain bases; (2) methylation studies coupled with gas-liquid chromatography and mass spectrometry to locate the bonds between the hexose units; and (3) enzymatic degradation to establish the sugar sequence and the anomeric configuration of the glycosidic links.

A new gene (alkB) of Escherichia coli that controls sensitivity to methyl methane sulfonate

Seven mutants of Escherichia coli were isolated that are sensitive to methyl methane sulfonate but not to UV light. They exhibited decreased host cell reactivation capacity for methyl methane sulfonate-treated phage lambda. Five of the mutations were mapped in the same region as alkA (previously called alk) and may indeed be identical to known mutations. Another mutation was found near nalA, and the gene responsible was named alkB. Its phenotype was different from that of ada, since the alkB mutant exhibited a normal adaptive response to N-methyl-N'-nitro-N-nitrosoguanidine. A third type of mutation was mapped near polA, but this mutant contained an almost normal level of DNA polymerase I activity.

Elastase-like enzyme in the aorta of spontaneously hypertensive rats

In an attempt to obtain information regarding vascular elastase in arterial hypertension, we examined biochemical changes in elastase-like enzyme activity, and the intravascular localization of elastase by immunohistochemical techniques in the aorta of spontaneously hypertensive rats (SHR). In the biochemical study, aortic elastase-like enzyme activity was significantly higher in SHR than in controls. Using an antibody against rat pancreatic elastase raised in the rabbit, it was demonstrated immunohistochemically that the enzyme was localized in the endothelial cells and subendothelial spaces in the aorta of control animals. In SHR, elastase was also demonstrated in medial smooth muscle cells and particularly in the modified smooth muscle cells in areas of intimal thickening. Some vacuoles in the smooth muscle cells also showed positive enzyme staining. Elastase seems to play an important role in the development of hypertensive vascular changes.

Semiquantitative histochemical investigation of lysosomal enzyme activities in the aortic endothelial cells of rats with renal hypertension

To obtain information about changes in lysosomal enzyme activities in the aortic endothelial cells in arterial hypertension, semi-quantitative histochemical investigations of acid phosphatase (Ac-Pase) and N-acetyl-beta-glucosaminidase (NAGase) activities in the aorta of rats with renal hypertension were performed on "Häutchen" monolayer preparations. The aortic endothelial cells in renal hypertensive animals showed increased Ac-Pase and NAGase activities compared with those in control normotensive rats and tended to increase with advancing age. These results, like our previous data from spontaneously hypertensive rats (SHR), indicated that degeneration of endothelial cells, expressed by increased lysosomal enzyme activity, was accelerated by hypertension, and the possible participation of genetic factors in the activation of these enzymes in SHR was ruled out. Increased lysosomal enzyme activity may be involved in the development of other hypertensive vascular changes.

Gas chromatographic method for the determination of urinary acetylpolyamines

A gas chromatographic method was developed for the determination of monoacetylputrescine, monoacetylcadaverine, N1-acetylspermidine and N8-acetylspermidine in human urine. The amines were isolated from urine by silica gel column chromatography. 1,10-Diaminodecane was used as internal standard. The amines were reacted with ethyl chloroformate in aqueous medium to four ethyloxycarbonyl derivatives prior to application to gas chromatography using a flame ionization detector. Separation and determination of the derivatives were carried out on a Uniport HP column (1.0 m) impregnated with 0.5% SP-1000 under temperature-programmed conditions. The monoacetylpolyamines could be measured accurately at the nanomole level. The method was used for the determination of the monoacetylpolyamines in urine of healthy volunteers. The values obtained were in the range of the published data.

Right ventricular aneurysm due to myocardial fatty infiltration: report of a case

A case of right ventricular aneurysm due to myocardial fatty infiltration was reported. A 39-year-old man was admitted to our hospital for evaluation of several episodes of syncopal attack presumably induced by malignant arrhythmia. There were frequent observations of ventricular premature beats, which occurred occasionally in couples. Cardiac catheterization disclosed the aneurysm situated at the outflow tract of the right ventricle. Aneurysmectomy was performed and the ventricular premature beats and syncopal attacks were effectively abolished. Etiology of the aneurysm was proved to be a fatty infiltration in the myocardium. To the best of our knowledge, there has been no case report of right ventricular aneurysm due to fatty infiltration in the myocardium.

Are purine bases enzymatically inserted into depurinated DNA in Escherichia coli?

An enzyme activity to incorporate labeled dATP or dGTP preferentially into depurinated DNA, found in an extract of Escherichia coli, does not seem to represent "purine insertase," but may be ascribed to a combined action of DNA polymerase I and AP endonuclease(s) on the basis of the following findings. (1) The activity was found in polA+ but not in polA-cells. (2) The base moiety and the alpha-phosphate group of the nucleotide were equally incorporated into the DNA.

A thrombotic tendency in patients with infective endocarditis

An attempt was made to evaluate a thrombotic tendency in cases of infective endocarditis (IE) from the viewpoint of the changes of platelets and coagulo-fibrinolysis. Qualitative changes of platelets by thrombi formation were detected by showing activated responses of platelets to adenosine diphosphate or collagen and by showing a high level of plasma beta-thromboglobulin which is released by platelets during aggregation. A mild hypercoagulable state without acceleration of fibrinolysis was also detected by showing low levels of plasma antithrombin III which is the most potent antithrombin in the blood and normal levels of plasma alpha 2-plasmin inhibitor in the blood. From above findings, it was concluded that a thrombotic tendency in cases of IE was clearly detected by qualitative changes of platelets by thrombi formation and by mild hypercoagulability without acceleration of fibrinolysis.

[A correlative study of M-mode echocardiograms and pathological findings in mitral ring calcification]

Correlation between pathologically proved mitral ring calcification (MRC) and M-mode echocardiographic findings was examined. Subjects for this study were 36 aged autopsy cases of MRC (14 men, 22 women) with a mean age of 78.9 years. Echocardiographic diagnosis of MRC was based upon the following criteria; a dense echo that moves parallel to the endocardium of the left ventricular posterior wall, immediately posterior to the mitral leaflet and its abrupt termination during a sweep of the beam to the left atrium and left ventricle. The length along the mitral ring and its maximal cross-sectional diameter of MRC were measured pathologically. Extension of MRC to the mitral commissures was also evaluated. The following results were obtained; (1) The larger was the size of MRC measured pathologically, the more it was easily diagnosed by echocardiography. (2) The width of MRC in the echocardiogram correlated well with the pathologically measured maximal cross-sectional diameter of MRC (r = 0.67, p less than 0.01). (3) Sensitivity in the diagnosis of MRC was better in the echocardiograms (58.3%) than in the plain chest X-ray films (38.9%) (p less than 0.05). The length of MRC equal to or greater than 30 mm was diagnosed in all by the echocardiograms. In contrast, only 78.6% of these were diagnosed by plain X-ray films. (4) When cases with MRC were divided into 2 groups according to the mitral diastolic descent rate (MDDR), the decreased group (MDDR less than 35 mm) had a significantly longer length of MRC (32.4 +/- 15.5 mm) than the non-decreased group (16.6 +/- 20.9 mm) (p less than 0.05). Extension of MRC to the mitral commissures was more frequently observed in the group with decreased MDDR than in non-decreased group (p less than 0.005). From these observations, it was suggested that mechanical restriction of the movement of the anterior mitral; leaflet due to involvement of the commissures by MRC may be a contributing factor for decreased MDDR. (5) Identification of echoes from the posterior mitral leaflet and the left ventricular posterior wall was difficult in cases with positive MRC echoes.

Electron microscopic studies on retinochoroidal atrophy in the human eye

Nine eyeballs were enucleated from nine patients with excessive myopia, secondary retinochoroidal atrophy, absolute glaucoma, uveal malignant melanoma, Behçet's disease and sympathetic ophthalmia. The retina and choroid were studied with light and electron microscopes. The results were: In excessive myopia, marked blockade of choriocapillaries was accompanied by progressive retinal degeneration. In secondary retinochoroidal atrophy induced by retrobulbar fibrosis, the choriocapillaries were partially blocked and the retina had markedly degenerated. In Behçet's disease, exudative inflammation was recognized in the choroid extending to the retina and causing retinal detachment, though the choriocapillaries remained morphologically normal. In sympathetic ophthalmia, both the choriocapillaries and the retina remained normal, though marked inflammation was recognized in the outer layer of the choroid. In absolute glaucoma, the fine structures of the choriocapillary were well preserved in spite of bulbar hypertonia. In uveal malignant melanoma, the ultra structure of the choriocapillary near the tumor was well preserved. The choriocapillaries were normal even when the retina had degenerated. Retinal degeneration was recognized when changes such as blockage, disappearance, dilatation and increased permeability were found in the choriocapillaries. Damage to the choriocapillaries might play an important role in inducing and developing retinochoroidal atrophy.

On the long-term development of shinkeishitsu-neurotics treated by Morita therapy. A statistical quantitative analysis

We considered the long-term development of shinkeishitsu-type neurotics (hypochondriacal neurosis: 154 cases; anxiety neurosis: 122 cases; obsessive neurosis: 436 cases; depressive neurosis: 123 cases) treated by Morita therapy by using the Life Table analysis. We obtained the following results: (i) at least 90% of the patients improved greatly within at most 8 years after admission; (ii) the mean time required for the patients to improve greatly are 38.0 months in hypochondriacal neurosis, 34.8 months in anxiety neurosis, 50.0 months in obsessive neurosis, and 47.4 months in depressive neurosis.

Hypercoagulability in patients with mitral stenosis -- from the viewpoint of the behavior of plasma antithrombin III and alpha2-plasmin inhibitor

The concentration of plasma antithrombin III (AT III) and the biological activity of plasma alpha2-plasmin inhibitor (alpha 2-PI) were measured in cases of mitral stenosis (MS) and rheumatic heart disease (RHD) without MS. Cases of MS showed the findings of the low levels of plasma AT III and normal or a little higher levels of plasma alpha 2-PI, that was not recognized in RHD without MS. This finding was interpreted to be hypercoagulable because of the acceleration of coagulation and of little or slight retardation of fibrinolysis. Besides, the influence of atrial fibrillation and chronic congestive heart failure on hypercoagulability in cases of MS was detected clearly, but the influence of them in cases of non-RHD was obscure. As the results, the severer the degree of MS, the clearer the hypercoagulable state. Therefore, the prethrombotic state existed in cases of MS, combined with blood flow disturbance due to atrial fibrillation or chronic congestive heart failure, endocardial damage resulted from rheumatic fever in an early stage and hypercoagulable state mentioned above in the present study. There was no significant difference between cases with and without thrombi in the degree of hypercoagulability in subjects with MS shown in the present work. It was concluded that the consumption of AT III caused the low levels of it in cases of MS, and that the low production of AT III in the liver rather than consumption caused the low levels of it in cases of non-RHD.

Phototropic Responses of Vaucheria geminata to Intermittent Blue Light Stimuli

Phototropic responses of a tip-growing coenocytic alga Vaucheria geminata to intermittent blue light pulses were analyzed. Curvatures caused by repeated light pulses separated by dark intervals of various lengths were as large as those obtained by continuous light of the same incident energy, unless the length of the dark interval exceeded a critical value of about 30 to 40 seconds. If the dark interval was longer than the critical length, bending no longer took place. Another response to intermittent irradiation was found. In a narrow range of light pulse and dark interval lengths, i.e. light pulses longer than 10 milliseconds and dark intervals shorter than a value ranging from 15 to 150 milliseconds, intermittent irradiation was more effective than continuous irradiation of the same total energy. In this region, the maximum response to repeated pulses was equal to the curvature caused by a continuous irradiation of the same total elapsed time. It is evident that in this condition the dark interval is not perceived and the alga responds as if it were in light. The results suggest that two different dark reactions may be involved in the phototropic response of this algal cell.