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Biomedical subjects

S Kodama

Publications and source records attributed to S Kodama.

At least 235 records · Page 13Linked to original sources
PubMed1985

Myocardial positron computed tomography with 13N-ammonia at rest and during exercise.

To assess the value of myocardial-perfusion positron computed tomography (PCT) for the evaluation of coronary artery disease (CAD), 13N-ammonia PCT using a whole-body multislice PCT device was performed at rest and during exercise in 6 normal subjects and 19 patients with angiographically documented CAD. The 13N-ammonia distribution in the myocardium was assessed both qualitatively and quantitatively. At rest and during exercise, the tracer distribution was homogeneous in the 6 normal cases. In the 19 patients with CAD, regional hypoperfusion was observed in 14 cases (74%) at rest and in 18 cases (95%) during exercise. Additional perfusion abnormalities were detecting during exercise in 12 cases. Segmental analysis of the myocardial perfusion identified 30 out of 34 stenosed vessels (88%) during exercise, with only one false-positive finding of diseased vessels (specificity, 98%). For the quantitative analysis of myocardial perfusion by PCT, the percentage of change in the tracer concentration in the same region between the rest and stress images was calculated. The concentration was slightly increased in normal myocardial segments (14.4% +/- 5.8%; P less than 0.001), whereas in CAD, it was significantly decreased in segments with stenosed vessels (-18.0% +/- 18.3%; P less than 0.02). We conclude that 13N-ammonia PCT at rest and during exercise provides high-quality images, and is a sensitive and effective technique for detecting CAD and identifying individual stenosed vessels. Furthermore, this technique makes possible quantitative assessment of the coronary reserve function.

Adult↗
PubMed1985

Adrenoleukodystrophy without adrenal insufficiency and its magnetic resonance imaging.

Fatty acids of plasma and erythrocyte membrane sphingomyelin were determined by gas chromatography-mass spectrometry in adrenoleukodystrophy (ALD) without adrenal insufficiency. Mass chromatogram tracing with the ion at m/z 143 [(CH2)6COOH3]+ showed increases of saturated very long chain fatty acids in plasma and erythrocyte membrane sphingomyelin in ALD. The C26:0/C22:0 ratios in plasma were 0.121, 0.057 and 0.007 in cases 1 and 2, and a control subject, respectively. The C26:0/C22:0 ratios in erythrocyte membrane sphingomyelin were 0.386, 0.211 and 0.093 in cases 1 and 2 and the control subject, respectively. The demyelinating process of ALD was clearly observed in both the inversion recovery 2100/500 and spin echo 2100/80 scans on magnetic resonance imaging. The magnetic resonance image in case 1 revealed widespread demyelinated lesions, involving almost the entire cerebrum and cerebellum, at 4 years after the onset, while that in case 2 revealed demyelinated lesions mainly limited to parieto-occipital areas at 1 year after the onset.

Adolescent↗
PubMed1985

Lymphocyte phosphorylase kinase activities in the sex-linked form of liver phosphorylase kinase deficiency.

Lymphocyte phosphorylase kinase activities were measured in normal controls and in patients with the sex-linked form of liver phosphorylase kinase deficiency. The reaction due to phosphorylase kinase activity in normal lymphocytes (2.7 X 10(6) in the reaction tube) was found to be linear within 20-60 min at 30 degrees C. The reaction was directly proportional to the concentration of lymphocytes within 1.5 X 10(6)-9.0 X 10(6), at 30 degrees C for 60 min. The phosphorylase kinase activity in normal lymphocytes, which were pre-incubated at 50 degrees C or 95 degrees C for 1 min, decreased to 60% at 50 degrees C and 10% at 95 degrees C of that after pre-incubation at 0 degree C for 1 min. The activity of normal controls was 125 +/- 23.5 U/10(10) lymphocytes. Those of the patients with liver phosphorylase kinase deficiency due to the sex-linked form were 43.5 U in case 1, 54.5 U in case 2, and 51.3 U in case 3, respectively and those of the mothers were within the normal range. These results suggest that phosphorylase kinase in lymphocytes might be form intermediate between liver and muscle phosphorylase kinase.

Child↗
PubMed1985

Transient hyperphenylalaninaemia with a high neopterin to biopterin ratio in urine.

A case of transient hyperphenylalaninaemia with a maturational delay of dihydropteridine synthesis is described. With the Guthrie test, the patient showed a blood phenylalanine level of 38 mg dl-1, which had fallen to a normal value without a phenylalanine restricted diet by 3 months of age. The neopterin level and the neopterin to biopterin ratio in the patient's urine were very high at 19 days of age. The blood phenylalanine level did not decrease when tetrahydrobiopterin (2.5 mg kg-1) was administered at 19 days of age, while administration of tetrahydrobiopterin (7.5 mg kg-1) at 20 days of age had decreased the blood phenylalanine level to 50% of the preloading level after 24 h. The oral phenylalanine loading test showed the pattern of classic phenylketonuria (PKU) at 15 days of age, but it showed the normal pattern at 1 year 8 months of age.

Alcohol Oxidoreductases↗
PubMed1985

Analysis of fatty acids and sphingosines from urinary sulfatides in a patient with metachromatic leukodystrophy by gas chromatography-mass spectrometry.

The urinary sulfatides in metachromatic leukodystrophy (MLD) were analyzed by gas chromatography-mass spectrometry. Fatty acids and long chain bases were obtained after methanolysis. C22:0 and C22h:0 were major components of the fatty acids distributed in the urinary sulfatides in MLD while they were only minor components of the fatty acids in the brain sulfatides in a control subject. These results were in accordance with the report of Philippart et al. It was suggested that the urinary sulfatides originated not in the brain but in other organs. The mass spectra of the trimethylsilyl derivatives of the hydroxy fatty acid methyl esters always showed peaks at m/z (M-15-28)+ and (M-59)+, indicating that the hydroxy group was on carbon 2. Two kinds of long chain base were identified: C18-sphingosine and 3-O-methyl-C18-sphingosine. The latter compound may be a by-product formed on methanolysis.

Brain Chemistry↗
PubMed1985

Effect of serum albumin on free fractions of phenobarbital and valproic acid in patients with convulsive seizures.

The free fractions of phenobarbital and valproic acid were assayed with Free-Level system I (Syva) and by an enzymatic immunoassay technique (EMIT) in 186 patients under chronic anti-convulsant therapy at precisely 2 hrs after they had taken the medicine at breakfast. The free fractions of PB ranged from 49 to 53% in monopharmacy and from 50 to 55% in polypharmacy. Those of VPA ranged from 10 to 12% in monopharmacy and from 8 to 11% in polypharmacy. The regression lines of the free fractions in PB monopharmacy and PB polypharmacy against serum albumin concentration indicated a negative correlation. There was no difference between the free fractions in PB monopharmacy and polypharmacy at the same albumin concentration. The regression lines of the free fractions in VPA monopharmacy and polypharmacy against serum albumin concentration indicated a negative correlation. The free fractions of VPA did not vary under a total VPA concentration of 80 micrograms/ml, while those of VPA above a total VPA concentration of 90 micrograms/ml increased with the total concentration, in the monopharmacy groups. On the other hand, free fractions of VPA in the polypharmacy groups did not vary with the total VPA concentration.

Adolescent↗
PubMed1985

Trinitrophenylation of rabbit skeletal myosin by 2,4,6-trinitrobenzene sulfonate and treatment of trinitrophenyl myosin with dithiothreitol.

Rabbit skeletal myosin was trinitrophenylated with 2,4,6-trinitrobenzene sulfonate (TNBS) in the presence or absence of inorganic pyrophosphate (PP1). When myosin trinitrophenylated either in the presence or absence of PP1 was treated with dithiothreitol (DTT), the absorbance at 345 nm of both trinitrophenylated myosins was decreased, as though the trinitrophenyl groups bound to myosin were removed. The DTT treatment also essentially reversed the inhibition of the EDTA-ATPase and Ca-ATPase activities that was caused by trinitrophenylation of myosin. These effects of trinitrophenylation and of DTT treatment were independent of the presence or absence of PP1 during the trinitrophenylation. In contrast, the PP1-induced formation of a difference spectrum of trinitrophenylated myosin was not affected by the DTT treatment. On the basis of these observations, it is suggested that the "reactive lysine residues," trinitrophenylation of which resulted in inhibition of the ATPase activities, are different from those whose trinitrophenyl groups show an altered spectrum on addition of PP1.

Adenosine Triphosphatases↗
PubMed1985

N-acetyl-beta-D-glucosaminidase activity in serum, kidney and liver of streptozotocin-induced diabetic rat.

Serum N-acetyl-beta-D-glucosaminidase (NAG) activity in streptozotocin-induced diabetic rats was significantly increased. There was neither a difference in total NAG activity in kidney and liver, nor in optimal pH of NAG in serum, kidney and liver between diabetic and control rats. The ratio of the thermounstable fraction of NAG increased in diabetic kidney and liver, while there was no difference in thermostability of between diabetic and control rats. Isoelectricfocusing of diabetic serum NAG indicated an increase in the neutral form. That of kidney and liver NAG indicated an increase in the acid form. These results may suggest that NAG clearance from the serum is decreased diabetic state.

Acetylglucosaminidase↗
PubMed1985

[A clinicopathological study of 11 patients with Paget's disease of the vulva].

A clinicopathological analysis of 11 patients with Paget's disease of the vulva was reported. A close association of this disease with cancer was strongly suggested in the histological examination. Nine of 11 patients had wide primary lesion; 4 patients had coexisting undifferentiated carcinoma (one patient with in situ sweat gland carcinoma) and one patient had squamous cell carcinoma in other lesion of the vulva. Five patients had downward growth of the tumor from the epidermis proper. There were, thus, only two patients who had Paget's cells confined within the epidermis. Three patients died of generalized metastasis of carcinoma and two patients had vulvar recurrence. The results of staining for PAS, PAS diastase resistant reaction, alcian blue, mucicarmin and carcinoembryonic antigen (CEA) were all positive in specimens with similar stainings to coexisting undifferentiated carcinoma of the vulva and metastasized lesions. CEA staining was positive in cytoplasm of Paget's cells and basal cells widely in the epidermis. It could be considered that the Paget's cells of the vulva originated multifocally from primitive stratum germinativum, which gave rise to the surface epithelium as well as all of the dermal appendages.

Aged↗
PubMed1985

Dynamic positron computed tomography of the heart with a high sensitivity positron camera and nitrogen-13 ammonia.

Dynamic positron computed tomography (PCT) of the heart was performed with a high-sensitivity, whole-body multislice PCT device and [13N]ammonia. Serial 15-sec dynamic study immediately after i.v. [13N]ammonia injection showed blood pool of the ventricular cavities in the first scan and myocardial images from the third scan in normal cases (n = 4). In patients with myocardial infarction (n = 8) and mitral valve disease (n = 2), tracer washout from the lung and myocardial peak time tended to be longer, suggesting presence of pulmonary congestion. PCT delineated tracer retention in the dorsal part of the lung. Serial 5-min late dynamic study in nine cases showed gradual increase in myocardial activity for 30 min in all normal segments and 42% of infarct segments, while less than 13% activity increase was observed in 50% of infarct segments. Thus, serial dynamic PCT with [13N]ammonia assessing tracer kinetics in the heart and lung is a valuable adjunct to the static myocardial perfusion imaging for evaluation of various cardiac disorders.

Ammonia↗
PubMed1985

[Evaluation of myocardial viability in myocardial infarction by thallium-201 emission computed tomography].

Stress thallium-201 emission computed tomography (ECT) was performed for 24 patients with myocardial infarction for quantitative evaluation of regional thallium redistribution and washout. ECT was performed using a rotating gamma camera 10 minutes and 2.5 hours after thallium injection during maximal exercise. Three short-axis sections and one central long-axis section were selected for the circumferential profile curves. Redistribution (%) and washout (%) were calculated from the stress and redistribution profile curves in each section. These parameters were evaluated by comparison with regional wall motion on radiographic contrast ventriculography. Forty-eight of the 52 segments (92%) with normal thallium uptake showed normal wall motion. Among the segments with abnormal thallium uptake, normal or hypokinetic wall motion was observed in 12 of 13 segments (92%) with more than 20% redistribution and in 16 of 19 segments (84%) with 10-20% redistribution, while it was observed in only 15 of 36 segments (42%) without redistribution (p less than 0.001). Among 48 infarcted segments, 16 segments (33%) showed significant redistribution on ECT analysis. Normal or hypokinetic wall motion was observed in three of five segments (60%) with more than 20% redistribution, and in 10 of 11 segments (91%) with 10-20% redistribution, while it was seen in only eight of 30 segments (17%) without redistribution (p less than 0.005).

Heart↗
PubMed1985

[Myocardial positron computed tomography using N-13 ammonia for evaluating coronary artery disease: comparison with thallium-201 emission computed tomography].

To assess myocardial perfusion in patients with coronary artery disease (CAD), N-13 ammonia positron computed tomography (PCT) was performed for 32 cases, and the PCT images were compared with those of single-photon emission computed tomography (SPECT) using thallium-201. Myocardial perfusion images were obtained with a whole-body multislice PCT device following the intravenous injection of 10 to 20 mCi N-13 ammonia at rest (32 cases) and during exercise (23 cases). Eleven cases underwent serial 15-20 second dynamic studies immediately following the N-13 ammonia injection. Serial dynamic study showed the blood-pool images in the first scan, and enabled assessment of tracer washout from the blood-pool, and the lung as well as washin into the myocardium. PCT provided clear resting myocardial perfusion images in all cases. PCT images were of higher quality than those of SPECT due to higher spatial resolution with less statistical noise, allowing delineation of the right ventricular myocardium and papillary muscles in many cases. Both PCT and SPECT detected perfusion abnormalities in 18 of the 19 cases with myocardial infarction, without false positive findings. PCT yielded stress myocardial images and permitted comparative evaluations of myocardial perfusions at rest and during exercise in all 23 cases. Perfusion abnormalities were detected in 14 cases (74%) at rest and in 18 cases (95%) during exercise among 19 patients with CAD. No false positives were observed, either by resting or stress PCT imaging. Stress myocardial PCT identified regional perfusion abnormalities in 30 of the 34 regions supplied by stenosed vessels (88%). High resolution PCT images enabled precise evaluation of myocardial perfusions which proved valuable for assessing myocardial perfusions before and after aorto-coronary bypass surgery. The present study proved advantages of N-13 ammonia PCT in creating three-dimensional high resolution images of the myocardium, which facilitates precise evaluation of myocardial perfusions. Furthermore, its potential capabilities in quantifying coronary reserve function will be very useful. This method should provide valuable pathophysiological information for CAD, as well as for metabolic PCT imaging.

Ammonia↗