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Biomedical subjects

N Hayashida

Publications and source records attributed to N Hayashida.

At least 145 records · Page 8Linked to original sources
PubMed1987

The gene for the 9 kd polypeptide, a possible apoprotein for the iron-sulfur centers A and B of the photosystem I complex, in tobacco chloroplast DNA.

The gene for the 9 kd polypeptide (a possible apoprotein for the iron-sulfur centers A and B) of photosystem I has been located in the small single-copy region of tobacco chloroplast DNA. This gene (psaC) was identified by comparing the N-terminal amino acid sequence of the spinach 9 kd polypeptide with the entire sequence of tobacco chloroplast genome. The gene organization is ndhE (101 codons)--263 bp spacer--psaC (81 codons)--94 bp spacer--ndhD (509 codons). Northern blot hybridization revealed that psaC is transcribed in the chloroplasts. The deduced amino acid sequence and secondary structure are presented. The predicted polypeptide is rich in cysteine residues and contains a unique repeated sequence.

Amino Acid Sequence↗
PubMed1987

Cerebral atrophy and slow wave sleep of abstinent chronic alcoholics.

Although a considerable decrease of slow wave sleep (SWS) has been observed in abstinent chronic alcoholics, the under-lying mechanism is still obscure. In the present study CT scans and polysomnographic recording were repeatedly conducted in nine chronic alcoholics. SWS was remarkably reduced in all the patients, but it was slightly restored in six patients on the 6th month after abstinence. On the other hand, enlargement was observed in the cortical sulci, cerebral fissures and ventricles in these patients. The enlargement of the cortical sulci was improved in five patients, and four of the patients showed increase of SWS. Although enlargement of the cerebral fissures and ventricles was improved in a few patients, in most of the patients who showed improvement in the cortical sulci SWS was increased. The results indicate that the decrease in SWS in abstinent alcoholics may have resulted from the atrophy of the cerebral cortex.

Adult↗
PubMed1987

Modulation of vascular dynamics by spontaneous contraction of smooth muscle in the isolated carotid artery of the rat.

Possible roles of smooth muscle contractions in the vascular dynamics were studied in the isolated rat large artery which has previously been shown to generate spontaneous rhythmic contractions depending upon the extracellular Ca2+. A cylindrical segment of the common carotid artery was superfused externally and perfused intraluminally by Tyrode solution, and the steady state intraluminal pressure (P)-volume (V) relationship of the vessel was obtained. The pressure buffering characteristic (Windkessel effect) of the vascular wall was evaluated by measuring the intraluminal pressure swing during application of external alternating pressure (semi-triangular pressure pulse, 0-120 mmHg, 300 cycle/min, "dynamic pressure load") to the intraluminal space. Effects on these vascular dynamics of inhibition of spontaneous smooth muscle contraction during superfusion of the preparation with nominally Ca2+-free Tyrode solution were investigated. Spontaneous rhythmic fluctuations of the intraluminal pressure (0.2-1.0 mmHg, 2-25 cycle/min), presumably due to contractions of vascular smooth muscles, were detected. The Ca2+-free solution abolished these spontaneous changes in the intraluminal pressure and reduced the baseline intraluminal pressure. The volume distensibility (delta V/(V X delta P] of the preparation at higher intraluminal fluid volumes (or pressures, higher wall stretch) was increased by Ca2+-free solution. The magnitude of intraluminal pressure swing and the maximum rate of changes in the pressure during application of "dynamic pressure load" were decreased in Ca2+-free solution. The results suggest that the inhibition of spontaneous contractions of smooth muscle by Ca2+-free solution may increase the volume distensibility and pressure-buffering function of the large elastic artery.

Animals↗
PubMed1986

The complete nucleotide sequence of the tobacco chloroplast genome: its gene organization and expression.

The complete nucleotide sequence (155 844 bp) of tobacco (Nicotiana tabacum var. Bright Yellow 4) chloroplast DNA has been determined. It contains two copies of an identical 25 339 bp inverted repeat, which are separated by a 86 684 bp and a 18 482 bp single-copy region. The genes for 4 different rRNAs, 30 different tRNAs, 39 different proteins and 11 other predicted protein coding genes have been located. Among them, 15 genes contain introns. Blot hybridization revealed that all rRNA and tRNA genes and 27 protein genes so far analysed are transcribed in the chloroplast and that primary transcripts of the split genes hitherto examined are spliced. Five sequences coding for proteins homologous to components of the respiratory-chain NADH dehydrogenase from human mitochondria have been found. The 30 tRNAs predicted from their genes are sufficient to read all codons if the ;two out of three' and ;U:N wobble' mechanisms operate in the chloroplast. Two sequences which autonomously replicate in yeast have also been mapped. The sequence and expression analyses indicate both prokaryotic and eukaryotic features of the chloroplast genes.

Journal Article↗
PubMed1986

A new surgical approach for control of pain in chronic pancreatitis: complete denervation of the pancreas.

With the aim of pain control in chronic pancreatitis without the morbidity of insulin-dependent diabetes, a new procedure was devised to completely resect the postganglionic pancreatic nerves and to totally free the pancreas from the posterior abdominal wall. This procedure was performed on two patients with follow-up periods of 24 and 10 months. Pain was resolved in both patients, and their blood glucose levels were substantially unchanged. This new approach offers a means of relieving pain with preservation of endocrine function in selected patients with chronic pancreatitis, especially in patients who have a small pancreatic duct.

Adult↗
PubMed1986

Mechanism of spontaneous rhythmic contraction in isolated rat large artery.

The mechanism of spontaneous contraction of vascular smooth muscles in the elastic artery was studied in a ring-shaped preparation isolated from the rat aorta. The observation of small changes in vascular tension with a high gain AC amplification of tension signal provided a reliable detection of spontaneous contractions. The spontaneous rhythmic contraction (RC) occurred consistently in the preparation taken from the thoracic aorta without external stimuli. The RC (frequency, 5-20 cycle/min; amplitude, 10-100 mg) was accompanied with small oscillatory changes in the membrane potential (2-5 mV, peak to peak). A reduction in temperature (below 30 degrees C) or superfusing the preparation with Ca-free solution inhibited the generation of RC. Ca-entry blockers (verapamil and nifedipine) also inhibited the RC. The cessation of RC by these procedures reduced the vascular tension by about 40% of control baseline tension. The application of adrenergic blockers had little effect on the pattern of RC and on the vascular tension. The results suggest that the RC is generated by a synchronization of electrical and mechanical activities in relatively small groups of smooth muscle cells, which depends upon the temperature and requires the Ca-entry into the cells. The process of initiation of spontaneous RC in the rat aorta was discussed.

Animals↗
PubMed1985

Hypomethylation of c-myc and epidermal growth factor receptor genes in human hepatocellular carcinoma and fetal liver.

The methylation state of cellular oncogenes (c-oncs) and epidermal growth factor (EGF) receptor gene from human liver tissues was examined by means of restriction endonuclease analysis. c-myc and EGF receptor gene from hepatocellular carcinoma and fetal liver were substantially hypomethylated in comparison with those genes from normal liver, while the extents of methylation of c-mos and c-Ki-ras genes were the same among these tissues. It can be speculated that the specific hypomethylation of c-myc and EGF receptor genes may be associated with the development of hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1983

Semi-supervised exercise training program for patients with coronary heart disease--its effectiveness and possible diagnostic implications for predicting their severity.

Semi-supervised physical training for 12 weeks was performed on 60 patients with coronary heart disease including 48 patients with myocardial infarction and 12 with angina pectoris. The training program consisted of medically-supervised training at the institute once a week and unsupervised training at home at least twice a week with an intensity of 70 to 85% of the maximum heart rate which had been attained by a symptom-limited multiphasic treadmill stress testing according to Bruce's protocol. The results showed an average increase of maximum oxygen consumption from 27.0 +/- 5.7 to 31.0 +/- 7.8 ml/min X kg (p less than 0.01) and of treadmill time from 507 +/- 120 to 673 +/- 140 sec (p less than 0.0001). Cardiovascular responses reduced at a submaximal level of exercise and remained unchanged at the maximal level of exercise. No detrimental events were encountered during the program. The left heart catheterization and coronary angiogram were performed on 35 out of 60 patients. The trainability was higher in patients with single-vessel disease than in those with multi-vessel disease. Based on these results, supervised training should be required mostly for patients with low physical fitness, and patients with high physical fitness can probably improve their physical abilities by self-training at home following a proper exercise program.

Adult↗
PubMed1982

Effects of the tumor promoter teleocidin on human hepatoma cells in tissue culture.

The tumor promoter teleocidin inhibited the proliferation of human HUH hepatoma cells in tissue culture. HUH cells cultured with teleocidin developed elongated cytoplasm. In addition, these biological effects of teleocidin were associated with a remarkable decrease in the amount of cellular fibronectin. The synthesis of structural proteins and the number of cell surface receptors for epidermal growth factor were not altered in cells treated with teleocidin, suggesting that teleocidin acted selectively on some of the cellular constituents such as fibronectin. The present data also suggest a possible relationship between the cellular fibronectin content and the biological characters of HUH cells.

Alkaloids↗