Search PubMed⌕ Search

Biomedical subjects

T Miyauchi

Publications and source records attributed to T Miyauchi.

At least 199 records · Page 11Linked to original sources
PubMed1990

Computerized EEG in schizophrenic patients.

We undertook a study of electroencephalograms (EEGs) in 30 right-handed, untreated patients (27.3 +/- 10.0 years; hebephrenic, 16; paranoid, 12; residual, 2) who fulfilled ICD-9 criteria for schizophrenia and compared them with sex- and age-matched controls by using the percentage of power in six EEG frequency bands calculated as a fraction of total power. T-statistic significance probability mapping (t-SPM) showed that, compared with normal controls, schizophrenics had more slow activity (delta, theta, and alpha 1) in the parieto-occipital regions, and more fast activity (beta 1) in the occipital regions. In contrast, alpha 2 activity decreased strikingly in the occipital regions and this decreased activity extended over much of the head. These findings were thought to indicate both cerebral hypofunction and excitability in acute untreated schizophrenia.

Adult↗
PubMed1990

Endothelin-3 concentrations in human plasma: the increased concentrations in patients undergoing haemodialysis.

Plasma immunoreactive endothelin-3 (ir-ET-3) concentrations were measured by a sandwich-enzyme immunoassay (sandwich-EIA) for endothelin-3 (ET-3). The assay method consists of two antibodies directed against N-terminal and C-terminal portions of ET-3. It detects as little as 0.1 pg/well of ET-3 without the crossreaction with endothelin-1, endothelin-2 and big ET-3. Plasma ir-ET-3 concentrations were found to be 0.45 +/- 0.07 pg/ml (mean +/- SD) in healthy volunteers, and were increased in patients undergoing haemodialysis (0.83 +/- 0.26 pg/ml, p less than 0.001). In reverse-phase HPLC, ir-ET-3 in normal plasma and in plasma of haemodialysis patients was eluted at the position of authentic ET-3, indicating that ir-ET-3 in plasma detected by the EIA was ET-3 itself. These results suggest that circulating ET-3 exists in normal human plasma and that production and/or metabolism of ET-3 may be altered in patients undergoing haemodialysis.

Adult↗
PubMed1990

Plasma concentrations of endothelin-1 in spontaneously hypertensive rats and DOCA-salt hypertensive rats.

To investigate the possible involvement of endothelin-1 (ET-1), an endothelium-derived potent vasoconstrictor peptide, in the pathophysiology of hypertension, plasma ET-1 levels in 15-week-old spontaneously hypertensive rats (SHR) and DOCA-salt hypertensive rats were measured with a sandwich-type enzyme immunoassay. The vasocontractile effect of ET-1 in aortic helical preparations was significantly more sensitive in DOCA-salt hypertensive rats than in control sham-operated rats, but plasma levels of ET-1 did not differ between them. Plasma ET-1 levels in genetically hypertensive rats (SHR and stroke-prone SHR) were significantly lower than those in age-matched normotensive Wistar-Kyoto (WKY) rats. The plasma concentrations of big ET-1, a precursor of ET-1, in both SHR and SHR-SP were significantly lower than those of WKY, suggesting that the production of ET-1 is decreased in rats of genetic hypertension. Although the vascular reactivity to ET-1 increased in both DOCA-salt hypertensive and genetically hypertensive rats, present findings of the plasma ET-1 levels suggest that the role of ET-1 in the vascular control system may be different in DOCA-salt hypertensive rats and genetically hypertensive rats.

Acetylcholine↗
PubMed1990

A sandwich-type enzyme immunoassay to detect immunoreactive big-endothelin-1 in plasma.

A sensitive sandwich-type enzyme immunoassay (sandwich-EIA) has been established for human big endothelin-1 (big-ET-1). A monoclonal antibody AwETN40 which recognizes the N terminal portion of big-ET-1 was used as an immobilized antibody. The Fab' fragment of rabbit antibodies to the human big-ET-1 C terminal peptide (22-38) was used as the enzyme-labeled antibody after being coupled to horseradish peroxidase (HRP). The assay is sensitive enough to detect as little as 0.2 pg/well (5 x 10(-17) mol/well) of big-ET-1 without crossreactivity with ET-1. Immunoreactive big-ET-1 in plasma was determined after being extracted with Sep-pak C-18 cartridges. The average levels were 5.2 +/- 1.0 pg/ml for males and 5.7 +/- 1.6 pg/ml for females (the values were corrected for recovery efficiency). Big-ET-1 was found to be eliminated from the blood stream at a slower rate than ET-1. This may be an important reason for the higher plasma levels of immunoreactive big-ET-1 compared to the levels of immunoreactive ET-1.

Adult↗
PubMed1990

Nonobstructive urinary tract dilatation in nephrogenic diabetes insipidus.

The follow-up study has been performed in 4 male patients with nephrogenic diabetes insipidus lasting for 4 to 15 years. Hydronephrosis or hydroureter appeared to be caused by polyuria with or without urinary tract obstruction. The efficacy of drainage operation is emphasized when polyuria surpasses the transporting ability of urine in the urinary tract.

Adolescent↗
PubMed1990

Basigin, a new, broadly distributed member of the immunoglobulin superfamily, has strong homology with both the immunoglobulin V domain and the beta-chain of major histocompatibility complex class II antigen.

Lotus tetragonolobus agglutinin (LTA) binds preferentially to early embryonic cells in the mouse. The affinity-purified antibody raised against LTA receptors from embryonal carcinoma cells were used to screen a lambda gt11 expression library of F9 embryonal carcinoma cells, resulting in detection of a cDNA clone specifying a new glycoprotein termed "basigin." The glycoprotein has been suggested to be a transmembrane one, and was found to be a new member of the immunoglobulin (Ig) superfamily. The molecular weight of basigin was largely in the range between 43,000 and 66,000, while that of the peptide portion with a putative signal sequence was inferred to be about 30,000. Significant levels of basigin mRNA were detected not only in embryonal carcinoma cells, but also in mouse embryos at 9-15 days of gestation and in various organs of the adult mouse. The Ig-like domain of basigin is unique, since it has strong homology to both the beta-chain of major histocompatibility class II antigen and the Ig V domain. The number of amino acids between the two conserved cysteine residues is intermediate between those of the Ig V and C domains. Therefore, basigin is an interesting protein in connection with the molecular evolution of the superfamily.

Amino Acid Sequence↗
PubMed1990

Involvement of endothelin in the regulation of human vascular tonus. Potent vasoconstrictor effect and existence in endothelial cells.

Endothelin, a recently discovered endothelium-derived peptide, has been reported to produce potent vasoconstriction in various vessels of experimental animals. To study the involvement of endothelin in the regulation of vascular tonus in humans, isolated human mesenteric arteries were investigated by both pharmacological and immunohistochemical methods. The vasoconstrictor action of endothelin-1 was examined on ring segments of human mesenteric arteries. Endothelin-1 induced a slowly developing and sustained contraction, with an EC50 value (half-maximal effective concentration) of 2.9 x 10(-9) M, two orders of magnitude smaller than that of norepinephrine (EC50 of 3.9 x 10(-7) M), indicating that the vasoconstrictor action of endothelin-1 is about 100 times more potent than that of norepinephrine. The contractile effect of endothelin-1 was affected neither by adrenergic, cholinergic, histaminergic, nor serotonergic antagonists, nor by inhibitors of arachidonic acid metabolism. The vasoconstrictor response to endothelin-1 was effectively antagonized by nicardipine, a dihydropyridine Ca2+ channel blocker. Endothelin-1 profoundly augmented contractile response to Ca2+ in partially depolarized tissues. Immunohistochemical studies revealed for the first time that endothelin-like immunoreactivity was localized in endothelial cells of human mesenteric artery. The results of the present study indicate that endothelin-1 is one of the most potent vasoconstrictors in the human mesenteric artery and that it induces vasoconstriction via an ultimately accelerating Ca2+ influx through voltage-dependent Ca2+ channels. Since endothelin-1 can be located in human endothelial cells, it may play an important physiological or pathophysiological role.

Adult↗
PubMed1990

[Carcinoma of the ureter after long-term use of analgesic [phenacetin derivative]--report of the two cases (spouses)].

Two cases (spouses) of carcinoma of the ureter possibly induced by long-term use of analgesic were presented. Case 1: A 66-year-old female with hematuria was diagnosed as a carcinoma of the ureter in January, 1985 and underwent resection of the left kidney and the ureter with partial resection of the urinary bladder. In December, 1988 she died due to recurrent cancer. Case 2: A 70-year-old male (a husband of case 1 patient) with hematuria was diagnosed as a carcinoma of the ureter in August, 1987 and underwent resection of the kidney and the ureter of the left side. In October, 1988 he died due to recurrent cancer. These two patients had used routinely phenacetin because of persistent headache for about 20 and 15 years, respectively and the presumed total dose was amounted to 4 and 2.5 kg, respectively.

Acetaminophen↗
PubMed1990

[Computerized analysis of EEG background activity in mono-therapeutic patients with epilepsy--relationships between antiepileptic drugs and types of seizures].

EEG background activity influenced by antiepileptic drugs (AED) was studied in 109 monotherapy and drug-free epileptic patients using t-Statistical Significance Probability Mappings (t-SPMs). Patients taking phenobarbital (PB) had an increase in alpha 1 and a decrease in alpha 2 activity in comparison with drug-free epileptics. Patients taking PB for generalized seizures with tonic-clonic convulsion only (GTC) also had a significant increase in alpha 1 and a decrease in alpha 2, whereas those with partial seizures (PS) had an increase in theta and beta 1 and a decrease in alpha 2 activity. Patients taking valproic acid (VPA) had a decrease in only beta 1 activity. Patients taking VPA for GTC showed an increase in delta activity, but those with PS did not show any changes. Patients taking carbamazepine (CBZ) for PS exhibited marked slowing with an increase in theta and alpha 1 and a decrease in alpha 2 activity. These results mean that changes in EEG due to AEDs differ depending on the type of seizures. More interestingly, discrepancy between EEG background activity and effects of AEDs was found: In PS type of seizures, the most effective CBZ exhibited striking slowing, PB was next, and VPA was last. In GTC, VPA resulted in greater slowing than PB.

Adult↗
PubMed1990

[Surgical treatment of renal cell carcinoma with bone metastasis].

Eighty-six patients with renal cell carcinoma underwent radical nephrectomy in Chiba Cancer Center Hospital. Fifteen of the 86 patients developed bone metastases. Seven of the 15 patients with bone metastases had received chemotherapy and radiotherapy. Six of the 15 patients underwent surgical treatment and two received radiotherapy alone. Of the six patients treated surgically for bone metastases, two patients were treated with wide resection and the remaining four patients underwent excision of the metastatic lesions in combination with radiotherapy, chemotherapy or immunotherapy. One of the two patients who underwent wide resection of a pelvic bone lesion is alive without evidence of disease for 6 years and 4 months. Another patient who underwent wide resection of femoral bone lesion survived for 14 years and 2 months but died of recurrent cancer. Pathologic findings of renal cell carcinoma in the long-time survivors showed adenocarcinoma of alveolar type of clear cell subtype and in grade 1. Wide resection of bone metastases of renal cell carcinoma can significantly prolong the survival time and improve the quality of life of the patients.

Aged↗
PubMed1990

[Pituitary hyperplasia in primary hypothyroidism].

One case of primary hypothyroidism with hyperplasia of the pituitary gland was reported. This enlargement was decreased after hormone replacement therapy. Pituitary hyperplasia occurs secondarily to primary endocrine gland failure. Reactive enlargement of the pituitary gland must be differentiated from primary pituitary abnormalities in order to avoid unnecessary surgery.

Adolescent↗
PubMed1989

The human endothelin family: three structurally and pharmacologically distinct isopeptides predicted by three separate genes.

Three distinct human endothelin-related genes were cloned by screening a genomic DNA library under a low hybridization stringency with a synthetic oligonucleotide probe encoding a portion of the endothelin sequence. Genomic Southern blot analysis with the same oligonucleotide probe showed three corresponding chromosomal loci not only in the human genome but also in porcine and rat genomes. The nucleotide sequences of the three human genes were highly conserved within the regions encoding the 21-residue (mature) endothelins, in spite of the fact that the immediately upstream exon sequences, which encode a part of the propeptides, retained little similarity. Moreover, each of the human genes predicted a putative 21-residue peptide, similar to but distinct from each other: (i) the "classical" endothelin (ET-1), (ii) [Trp6,Leu7]endothelin (ET-2), and (iii) [Thr2,Phe4,Thr5,Tyr6, Lys7,Tyr14]endothelin (ET-3). Synthetic ET-1, ET-2, and ET-3 were prepared according to the deduced amino acid sequences, and the biological activities were assayed by contraction of isolated porcine coronary artery strips and by intravenous injection to anesthetized rats. All these synthetic peptides produced strong vasoconstrictor and pressor responses. However, the quantitative profiles of the pharmacological activities were considerably different among the three isopeptides, suggesting the possible existence of endothelin receptor subtypes.

Animals↗
PubMed1989

Elimination of intravenously injected endothelin-1 from the circulation of the rat.

The rate of elimination and the fate of endothelin-1 (ET-1) from the circulating blood was studied in urethane-anesthetized rats by intravenous injection of [125I]-labeled ET-1. The vasoconstrictor activities of the iodinated ET-1 were confirmed to be similar to those of native ET-1. Following i.v. bolus injection of 30 pmol/kg of [125I]-ET-1 into the femoral vein, the total radioactivity of the right atrial blood decayed rapidly, with a half-life of 7 min. At 5 min after the injection, the administered radioactivity distributed chiefly to the parenchyma of the lungs, kidneys, and liver. The analysis of the chemical form of labeled peptides from the plasma by reverse-phase high-performance liquid chromatography (HPLC) demonstrated no appreciable amount of degraded forms of [125I]-ET-1 in the blood for up to 60 min. [125I]-ET-1 was also stable for up to 60 min upon incubation in vitro with heparinized rat blood at 37 degrees C. Even when the same amount of labeled ET-1 was injected together with a pressor dose (1,500 pmol/kg) of cold ET-1, the half-life of the radioactivity in the bloodstream was exactly identical to that for [125I]-ET-1 alone. Nevertheless, the pressor response continued for more than 90 min after i.v. bolus injection of 1500 pmol/kg of ET-1 to the rat. These results clearly indicate that the elimination of ET-1 from circulating blood and the ET-1-induced pressor response are not in parallel, and the relatively rapid disappearance of ET-1 from the bloodstream is mostly due to the removal of the peptide by the parenchymal tissues, in the anesthetized rat. The long-lasting pressor action of ET-1 may be ascribed to our previous finding that the dissociation of ET-1 from its specific binding sites on vascular smooth muscle cells is extremely slow.

Animals↗
PubMed1989

Purification and characterization of glycylprolyl aminopeptidase from Bacteroides gingivalis.

A glycylprocyl aminopeptidase from cell extracts of Bacteriodes gingivalis 381 was purified 1058-fold by hydrophobic adsorbent, HPLC anion exchange, and HPLC gel filtration column chromatography. The final enzyme preparation was homogeneous with a molecular weight of 75,000 daltons by SDS-PAGE, and the isoelectric point was 6.2. The optimum pH of the enzyme was 8.0, and the enzyme activity was inhibited by DFP Ni2+ and Hg2+.

Aminopeptidases↗