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Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 1,279 records · Page 71Linked to original sources
PubMed1986

Profiling of organic acids and polyols in nerves of uraemic and non-uraemic patients.

Organic acids, polyols and lipid-bound polyols in the cauda equina nerves of uraemic patients and non-uraemic patients were analysed with high-resolution gas chromatography-mass spectrometry. In the uraemic nervous tissue, the concentrations of myoinositol and 4-hydroxyphenylacetic acid were increased. Levulinic acid was first detected in the nervous tissue as a normal component. 1-Deoxyglucose and free and lipid phosphatide scylloinositol were detected in the nervous tissue as normal components.

Acids↗
PubMed1986

In vitro transcription of a chromatin-like complex of major core protein VII and DNA of adenovirus serotype 2.

Major core protein VII of adenovirus serotype 2 (Ad2) is thought to play a role as a histone octamer in eukaryotic cells. We compared the template activity of the VII-DNA complex formed in vitro with that of protein-free DNA. Hybridization assay of in vitro transcripts showed that transcription from regions located in the middle of Ad2 DNA decreased when Ad2 DNA formed a complex with VII. This suggests that the chromatin structure plays a role in regulation of transcription of the adenovirus genome.

Adenoviridae↗
PubMed1986

Further characterization and amino acid sequence of m-type thioredoxins from spinach chloroplasts.

The complete primary structure of m-type thioredoxin from spinach chloroplasts has been sequenced by conventional sequencing including fragmentation, Edman degradation and carboxypeptidase digestion. As already reported [Tsugita, A., Maeda, K. & Schürmann, P. (1983) Biochem. Biophys. Res. Commun. 115, 1-7] these thioredoxins contain the same active-site sequence as thioredoxins from other sources. Based on the amino acid sequence thioredoxin mc contains 103 residues, has a relative molecular mass of 11425 and a molar absorption coefficient at 280 nm of 19 300 M-1 cm-1. The spinach thioredoxin mc has an overall homology of 44% with the thioredoxin from Escherichia coli mainly due to differences in the N-terminal and C-terminal regions.

Amino Acid Sequence↗
PubMed1986

Transient responses in cardiac function below, at, and above anaerobic threshold.

Exercise-induced alterations in cardiac function during graded cycling with submaximal and maximal intensities were studied in 13 trained and 13 untrained young men. Stroke volume (SV) and stroke index (SI) at rest and during submaximal and maximal exercise, determined by impedance cardiography, were consistently greater in the trained than in the less fit group. Training-induced bradycardia was evident in the trained group at rest and during submaximal exercise. Even when SV and SI were compared at the same absolute heart rate and left ventricular ejection time, those for the trained group were markedly greater than those for the untrained. SV for the untrained group was relatively diminished above the work rate corresponding to the anaerobic threshold. The difference in SV during exercise may be attributed to inadequate filling due to the smaller stretch of myocardial fibers in diastole and/or lesser systolic emptying of the left ventricle due to the reduced myocardial contractility in systole of untrained individuals.

Adult↗
PubMed1986

Purification and characterisation of MHC class I antigen from rat liver with monoclonal antibody.

We have described three monoclonal antibodies (HAM1, HAM2, and HAM3) to rat liver cell membrane glycoproteins. Recently also we reported another monoclonal antibody (HAM4) to rat hepato-renal membrane antigen. Using these monoclonal antibodies, it is possible to purify membrane antigens. This paper describes the details of the purification and the nature of the antigen purified with one of the monoclonal antibodies (HAM2) to rat liver cell membrane glycoproteins. Antigen was purified with immunoaffinity column. The amino acid composition was determined and compared with those of mice MHC class I antigen (H-2) and with the rat lymphocyte membrane antigens which were purified with monoclonal antibodies and of which amino acids compositions were determined.

Amino Acids↗
PubMed1986

Mutagenic activation of aflatoxin B1 by several forms of purified cytochrome P-450.

Metabolic activation by several forms of purified cytochrome P-450 of aflatoxin B1 to a product(s) mutagenic to Salmonella typhimurium TA100 was examined. Of the 5 forms of cytochrome P-450 purified from liver microsomes of untreated and PCB-treated male rats, a constitutive form purified from untreated male rats, P-450-male, and a high-spin form of cytochrome P-450, P-448-H, from PCB-treated rats were highly active.

Aflatoxin B1↗
PubMed1986

The responsiveness of Clare-Bishop neurons to size cues for motion stereopsis.

The responsiveness to the size cue, and a combination of the size and motion cues contained in 3-dimensional motion of a visual stimulus was studied in 118 Clare-Bishop (CB) cells, including 37 and 10 cells selectively responsive to approaching (AP) and to recessive motion along the axis through the center of the receptive area and the nose (RC), 40 cells responsive to the frontoparallel motion in the horizontal direction (FP), 23 cells rather non-selectively responsive to the two types of motion (NS) and 8 cells responsive to the size cue but unresponsive to the 3-dimensional motion (SZ). About three quarters of the AP cells (27/37) were responsive to both an increase in the stimulus size and divergent motion of the retinal images in the two eyes, which represents the size and motion cues for the approaching motion along the axis through the center of the receptive area and the nose, and were optimally excited by a combination of the two visual cues. About the same fraction of the RC cells (6/10) was responsive to the motion (convergent motion) and size cues (a decrease in stimulus size), and optimally excited by a combination of the two visual cues. In contrast, only a small fraction of the FP cells (6/40) were sensitive to the size cue, and all FP cells were optimally excited by the single presentation of the motion cue for the frontoparallel motion (either right- or leftward motion in both eyes). Responses were frequently (18/40) smaller for the combined presentation of the two visual cues than for the single presentation of the motion cue. Similarly, a small fraction of the NS cells (7/23) was sensitive to the size cue, but many of them (16/23) were non-selectively responsive to the size cues for the approaching and recessive motion. A similar study in an additional 108 (78 AP and 30 RC) cells which were responsive to approaching or recessive motion vertically or obliquely deviating from the axis through the center of the receptive area and the nose demonstrated that they were also sensitive to both motion and size cues for that approaching or recessive motion, and were optimally excited by a combination of the two visual cues. These findings indicate that the CB cell responsiveness to 3-dimensional motion is based on the integration of the motion and size signals conveyed through the two eyes. A model of neuronal circuitry was constructed to explain the CB cell responsiveness to the motion and size signals.

Action Potentials↗
PubMed1986

Increasing pre-excitation ("concertina effect") during vasospastic angina.

A patient with Wolff-Parkinson-White syndrome and variant angina developed progressive ST-segment elevation in the inferior leads after hyperventilation-induced right coronary artery spasm. At the same time, increasing pre-excitation ("concertina effect") developed with gradual prolongation of the AH interval on His bundle ECG. The ECG changes promptly disappeared after sublingual nitroglycerin, with termination of the chest pain. Transient ischemia induced by coronary artery spasm can be an etiology of increasing pre-excitation.

Angina Pectoris, Variant↗
PubMed1986

Study on abnormalities in the appearance of finger and palm prints in children with cleft lip, alveolus, and palate.

The aetiology of abnormalities in the appearance of finger and palm prints in children with cleft lip, alveolus, and palate was examined by comparing the frequencies of abnormalities in hereditary cases and sporadic cases, and those in hereditary cases with those in their parents. The following results were obtained: Comparison of hereditary cases and sporadic cases. Abnormalities in the appearance of finger and palm prints were greater in hereditary cases than in sporadic cases. Abnormalities in the appearance of finger and palm prints were greater in parents of hereditary cases than in parents of sporadic cases. The rate of agreement in the appearance of finger and palm prints between parents and children was greater in hereditary cases than in sporadic cases. Comparison within hereditary cases. Abnormalities in the appearance of finger and palm prints were greater in affected children when one of the parents was affected (gamma = 1/2) than when both parents were normal (gamma = less than 1/2). Abnormalities in the appearance of finger and palm prints were greater in parents, one of whom was affected, than in normal parents. The rate of agreement in the appearance of finger and palm prints of parents, one of whom was affected, and their gamma = 1/2 children cases was higher than of normal parents and their gamma = less than 1/2 children. It was concluded that the above results could be explained by multifactorial inheritance.

Adolescent↗
PubMed1986

The developmental changes of the extracerebral space seen on ultrasonography in neonates and infants.

Ultrasonographic examination was performed in 70 healthy neonates and infants using a real-time sector scanner array machine with a 7.5-MHz transducer and a 4 cm waterbag. The skin, subcutaneous tissue, dura mater, interhemispheric fissure, gyri, sulci and sagittal sinus could be clearly visualized on ultrasonography (US), and the distance from the dura mater to the brain surface was determined. The extracerebral space under the anterior fontanel increased until 3 months after birth, and decreased gradually from 3 months to 12 months. The width and structure of the extracerebral space seen on US can be useful as parameters for assessing the process of brain growth and for detecting extra- and intracerebral pathologies in neonates and infants.

Brain↗
PubMed1986

A clinical trial of interferon therapy in a case of rapidly progressive SSPE.

A 6-year-old Japanese boy with rapidly progressive SSPE was reported, who received interferon therapy and recovered from stage III-A to stage II-B according to the criteria of Freeman. This is the first report of the beneficial therapeutic effect of interferon therapy on rapidly progressive SSPE, which is lethal and poorly responded to any kind of previous therapeutic trials.

Child↗
PubMed1986

Effects of phenobarbital, 3-methylcholanthrene and polychlorinated biphenyls on sex-specific forms of cytochrome P-450 in liver microsomes of rats.

The effects of treatment with phenobarbital, 3-methylcholanthrene or polychlorinated biphenyls (PCB) on the amounts of sex-specific forms of cytochrome P-450, namely P-450-male and P-450-female, in male and female rats were studied. Although treatment with phenobarbital, 3-methylcholanthrene or PCB markedly increased the total amount of hepatic cytochrome P-450, P-450-male and P-450-female were rather decreased or not significantly changed. Thus, the percentages of P-450-male and P-450-female in the total cytochrome P-450 were decreased in liver microsomes from the treated rats. The increases in specific cytochrome P-450, such as P-448-H, P-448-L, and P-450I-c accounted for the increase in the total amount of cytochrome P-450 in the treated rats. The treatment with phenobarbital or PCB increased the activities of testosterone 16 alpha-hydroxylase, benzo(a)pyrene hydroxylase and aminopyrine N-demethylase more markedly in female rats than in male rats. Similarly, the treatment with 3-methylcholanthrene increased benzo(a)pyrene hydroxylase more markedly in female rats. Therefore, the sex-differences in testosterone 16 alpha-hydroxylase, benzo(a)pyrene hydroxylase, and aminopyrine N-demethylase activities became smaller after the drug treatment. These results indicate that sex-specific P-450-male and P-450-female were unaffected, or even depressed by the agents in some cases.

Animals↗
PubMed1986

High 1,25-dihydroxyvitamin D and low 25-hydroxyvitamin D concentrations in plasma in patients receiving antiepileptic drugs.

Plasma 25-hydroxyvitamin D (25-OH D), 1,25-dihydroxyvitamin D (1,25-(OH)2 D) and parathyroid hormone (PTH) concentrations were determined in 30 outpatients receiving various antiepileptic drugs (AED). None of the patients exhibited high plasma PTH levels. The plasma 1,25-(OH)2 D levels were normal or high, although in a third of the patients the 25-OH D levels were reduced. There was a correlation between the 25-OH D and serum calcium levels. These findings suggest that the low plasma concentrations of 25-OH D, not 1,25-(OH)2 D, might play an important part in the occurrence of AED-induced disturbances of bone metabolism.

Adolescent↗
PubMed1986

Chronic lithium treatment decreases [3H]-imipramine binding in rat brain.

The effect of a chronic lithium treatment on the [3H]-imipramine binding in rat brain regions was investigated. In the striatum, an oral administration of lithium for 30 days induced a decrease in the [3H]-imipramine binding at the concentration of [3H]-imipramine, 1.0 nM, compared to the control. Lithium did not affect the [3H]-imipramine binding in the cerebral cortex and hypothalamus. A Scatchard analysis in the striatum revealed a decrease in the number of [3H]-imipramine binding sites with no changes in the binding affinity. These results suggest that the chronic lithium treatment may produce subsensitivity of the [3H]-imipramine binding in man and that this effect of the ion may be closely related to the established effect of lithium in the treatment of affective disorders.

Animals↗