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Biomedical subjects

Y Okano

Publications and source records attributed to Y Okano.

At least 271 records · Page 15Linked to original sources
PubMed1986

[Effects of ambroxol on pulmonary surfactant--analysis of the fatty acid composition of phosphatidylcholine in the sputum and normal respiratory tract fluid in rabbits].

The mechanism of action of secretagogic expectorants (ex., ambroxol) has not been clarified. Recently, attention has been directed to the relationship of their action to pulmonary surfactants. In the present study, the fatty acid (FA) composition of phosphatidylcholine (PC), which is the main physiological surfactant, was investigated using sputum, respiratory tract fluid, mucin-like substance, lung washings and lung tissue of rabbits. Effects of ambroxol (20 mg/kg, i.s.) on several parameters such as output volume, FA contents of PC, protein content and viscosity of respiratory tract fluid of rabbits were also investigated. In respiratory tract fluid, lung washings and mucin-like substance of rabbits, saturated FA, especially C16:0, were predominant components of PC; while in sputum and lung tissue of rabbits and respiratory tract fluid of hens, unsaturated FA, especially C18:1 and C18:2, were more predominant components in comparison with those in the above specimens. Ambroxol significantly increased the contents of C16:0, saturated FA and total FA of PC, and it also increased protein content with an increase in the viscosity of respiratory tract fluid. These results suggest that in the respiratory tract fluid of rabbits, PCs are pulmonary surfactants, and the increasing secretion of pulmonary surfactant is likely to be involved in the expectorant action of ambroxol.

Ambroxol↗
PubMed1986

Arachidonic acid mobilization among phospholipids in murine mastocytoma P-815 cells: role of ether-linked phospholipids.

The ethanolamine-containing glycerophospholipids, choline-containing glycerophospholipids, and phosphatidylinositol fractions are major sources of arachidonic acid in murine mastocytoma P-815 cloned cells. The choline-linked fraction contained high arachidonic acid contents in 1-O-alkyl-2-acyl- (18%) and 1,2-diacyl-sn-glycero-3-phosphocholine (11%), with smaller amounts in 1-O-alk-1'-enyl-2-acyl species, whereas the arachidonic acid content of the ethanolamine-linked fraction was high in 1-O-alk-1'-enyl-2-acyl (26%) and 1,2-diacyl species (15%) and low in 1-O-alkyl-2-acyl species. The uptake and transfer of [3H]arachidonic acid into the 1,2-diacyl and ether classes of choline-containing glycerophospholipids and ethanolamine-containing glycerophospholipids in mastocytoma cells were examined. There was very rapid incorporation of radioactive arachidonic acid into mastocytoma cells that leveled off after 30 min. By labeling cells with [3H]arachidonic acid for 7.5 min, the radioactivity was recovered in the choline-containing glycerophospholipids (43%), phosphatidylinositol (32%), and ethanolamine-containing glycerophospholipids (20%) with little in other phospholipids, neutral lipid, or free fatty acid fractions. Upon reincubation of the mastocytoma cells in the radiolabel-free medium, the [3H]arachidonate radioactivity was gradually lost from the choline-containing glycerophospholipids fraction and, concomitantly, increased in ethanolamine-containing glycerophospholipids. At the zero time of reincubation, most of the radioactivity was recovered in the 1,2-diacyl species of both choline-containing glycerophospholipids and ethanolamine-containing glycerophospholipids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Assessment of mucociliary clearance in patients with tracheobronchoplasty using radioaerosol.

To assess mucociliary clearance in patients with tracheobronchoplasty, radioaerosol inhalation scanning was performed in 14 patients. The unilateral total lung clearance curve was fitted into two compartmental curves, fast and slow, by least-squares techniques in order to assess mucociliary clearance of the bronchial tree quantitatively. Half-time (T 1/2) of the curve resulting from the subtraction of the slow compartment curve from the fast compartment curve was calculated. The mucociliary clearance of the bronchial tree post so-called lobectomy (N = 5) was intact (T 1/2; 13.1 +/- 7.3 min). On the other hand, the mucociliary clearance of the bronchial tree postreconstruction (N = 14) was prolonged (T 1/2; 28.3 +/- 10.6 min), compared with that of the control bronchial tree (N = 15, T 1/2; 11.9 +/- 3.9 min) (p less than 0.01). However, the mucociliary clearance of the bronchial tree postreconstruction showed improvement with the passage of time, and the original clearance was regained 5 to 12 mo after the operation. Radioaerosol inhalation studies revealed both the degree of impairment and the recovery time of mucociliary clearance in patients post-tracheobronchoplasty.

Adult↗
PubMed1985

Sleep-promoting effects of intraperitoneally administered uridine in unrestrained rats.

An intraperitoneal injection of 0.1 nmol uridine in rats resulted in a transient excess slow-wave sleep if administered shortly before onset of the dark period. The sleep latency was remarkably shortened. A small dose (0.01 nmol) and larger doses (1, 10, 100 nmol) caused no effect. Uridine at a dose of 0.1 nmol was entirely ineffective if injected shortly before onset of the light period, while it resulted in transient excess paradoxical sleep if injected at an early phase of the light period. It is concluded that uridine, if timely administered through a systemic route, may pass the blood-brain barrier to modulate sleep in rats.

Animals↗
PubMed1985

Inhibitory action of phorbol myristate acetate on histamine secretion and polyphosphoinositide turnover induced by compound 48/80 in mast cells.

Rat peritoneal mast cells which had been preincubated with phorbol myristate acetate (PMA, 10 - 100 ng/ml) for 5 min did not elicit the full histamine secretion induced by a potent secretagogue, compound 48/80. Furthermore, this PMA-treatment was found to inhibit the agonist-mediated hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) in [32P]labeled cells. However, it was also observed that the level of [32P]PIP2 was markedly reduced by 5 min-incubation with PMA. This suggests the enhanced hydrolysis of PIP2 by PMA which was reflected in a greater formation of inositol trisphosphate (IP3). These observations indicate that the formation of IP3 may not be profoundly related to secretory response in mast cells.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1985

A wasp venom mastoparan-induced polyphosphoinositide breakdown in rat peritoneal mast cells.

The phospholipid metabolism of rat peritoneal mast cells stimulated with mastoparan, a secretagogue purified from wasp venom, was investigated. Mastoparan at 20 micrograms/ml caused a rapid secretion of histamine. Mastoparan induced a transient decrease of phosphatidylinositol 4,5-biphosphate on 32P labeling and generation of a water-soluble degradation product, inositol trisphosphate on [3H]inositol labeling, suggesting the activation of phospholipase C upon stimulation.

Animals↗
PubMed1985

Accessory cells reduce lipoprotein suppression of lymphocyte activation.

Plasma lipoproteins of d less than or equal to 1.063 g/ml suppress lymphocyte activation triggered in vitro by polyclonal T cell mitogens. The extent of suppression decreases as the number of accessory cells per culture increases. Accessory cells isolated by glass adherence and by counter-flow centrifugation reduce lipoprotein suppression to the same extent. Modulation of lipoprotein suppression by accessory cells is independent of the amount and type of polyclonal activator. Reduction of lipoprotein suppression requires viable accessory cells and that they be present with lymphocytes, mitogen and lipoproteins during the initial 24-h culture period. It is within this same time period that lipoproteins exert their suppressive effect. Accessory cells isolated from a patient with the homozygous form (receptor-defective) of familial hypercholesterolemia also reduce the extent of lipoprotein suppression, suggesting that modulation is not mediated by the classic low density lipoprotein receptor. There appear to be at least two mechanisms by which accessory cells may alter lipoprotein suppression of T lymphocyte activation: by secretion of a soluble factor, probably not interleukin 1, that decreases the extent of suppression and by direct modification of the population of suppressive lipoproteins. Neither mechanism accounts for the lipoprotein-enhanced activation that occurs when cultures contain approximately equal numbers of T lymphocytes and accessory cells.

Antigen-Presenting Cells↗
PubMed1985

Arachidonic acid release in rat peritoneal mast cells stimulated with antigen, ionophore A23187, and compound 48/80.

Rat peritoneal mast cells respond to various types of secretagogues, such as antigen (receptor-mediated), A23187 (calcium mobilizing), and compound 48/80 (membrane perturbing), and release arachidonic acid from membrane phospholipids prelabeled with [3H]arachidonate. The rate of arachidonic acid liberation varied from one stimulant to the other. Ionophore A23187 (0.1 micrograms/ml) appeared to be most potent in releasing arachidonate among the three stimulants at which doses each secretagogue caused almost equivalent histamine secretion. However, upon stimulation with these three secretagogues, the radioactivity of phosphatidylcholine (PC) was markedly reduced with a concomitant increase of arachidonate radioactivity. Hydrolysis of PC by phospholipase A2 is likely to be the major route of arachidonic acid liberation in either IgE-mediated or non-IgE activation in mast cells.

Animals↗
PubMed1985

Concentration of 99mTc-Sn-N-pyridoxyl-5-methyltryptophan, a biliary agent, in distant metastases of hepatomas.

During the last 2 years, eight patients with hepatocellular carcinoma who were suspected of having distant metastases have been studied to determine whether a new biliary agent, 99mTc-Sn-N-pyridoxyl-5-methyltryptophan (99mTc-PMT), is taken up by extrahepatic tumors. In all eight patients, scintigrams showed a clearly increased uptake of 99mTc-PMT radioactivity by the extrahepatic tumors. In contrast, an increased uptake by the tumors of gallium citrate Ga 67 was only detected in four of the seven patients examined. The results obtained in this study suggest that 99mTc-PMT is useful both for characterizing the nature of extrahepatic tumors in patients with hepatoma and for detecting the metastases.

Adult↗
PubMed1985

Histocytologic diagnosis of pancreatic cancer by percutaneous aspiration biopsy under ultrasonic guidance.

Percutaneous aspiration biopsy of the pancreas using a heparinized 22-gauge fine needle was performed under ultrasonic guidance in five patients with benign pancreatic diseases and in 18 patients with pancreatic cancer. Using a heparinized needle and syringe, it was possible to make good smears containing abundant tumor cells and to obtain small tissue specimens. Using egg albumin as binding material, a new cell-block technic was developed to conveniently obtain histologic specimens. In this way, a correct diagnosis was made cytologically in all 23 patients suspected of having a pancreatic malignancy. Histologic specimens were obtained in 22 (95.6%) our of 23 patients. A correct diagnosis was established histologically in all patients from whom histologic materials were obtained. This procedure thus has proved a very reliable method for diagnosing pancreatic cancer.

Adenocarcinoma↗
PubMed1985

Suppression of lymphocyte activation by plasma lipoproteins: modulation by cell number and type.

Plasma lipoproteins containing apolipoproteins B and E, as well as delipidated water-soluble apoE, suppress lymphocyte activation by polyclonal T cell mitogens in vitro. This report establishes that apoB100, isolated from human plasma LDL, also suppresses lymphocyte activation. Prereplicative mitogen-induced events as well as DNA synthesis and cell division are suppressed. A number of experimental variables influence the extent to which lipoproteins suppress lymphocyte activation. Lipoproteins isolated from different donors vary widely in suppressive potency. In addition, the extent of suppression depends on the cultured cell density: suppression at fixed concentration of lipoprotein or apolipoprotein decreases as the number of cells increases. When the total number of cells per culture and the suppressor concentration are both fixed, the extent of suppression decreases as the percent T cells or monocytes increases. In the lymphatic tissue where lymphocytes and accessory cells are concentrated, plasma lipoproteins may play a less important immunoregulatory role in normolipidemic subjects compared to that in subjects with hyperlipoproteinemia, particularly hypercholesterolemia, since the tissue concentration of lipoproteins in hyperlipidemic subjects is likely to be elevated.

Adult↗
PubMed1985

Imino acid and related alicyclic amine levels in biological fluids.

Imino acid and related alicyclic amine concentrations in blood and urine of mammals including humans were concurrently determined by a selected ion monitoring technique. Nanomole levels of proline and pipecolic acid, and pyrrolidine and piperidine as well, were found in human urine. Proline levels but not pipecolic acid levels were higher in blood of humans than in urine. Pyrrolidine and piperidine levels in blood of humans were picomole levels and much lower than those in urine. Similar tendencies were also recognized when these 4 compounds were analyzed using animal blood and urine, although the levels were generally higher in animals than in humans. Significantly high concentrations of the imino acids and the amines were found also in animal semen.

Amines↗
PubMed1985

Value of heparinized fine-needle aspiration biopsy in liver malignancy.

The accuracy of diagnosis of hepatic malignancy by percutaneous aspiration biopsy was compared using heparinized and nonheparinized 22-gauge needles. When a heparinized instrument was used, it was able to accurately diagnose malignancy and cytologic types of exfoliative cells. Heparinization also made it possible to recover small tissue fragments and make ultrathin sections for histologic examination. In this way, material suitable for cytologic and histologic examination was obtained from 100% and 95%, respectively, of 59 patients suspected of having hepatic malignancy. A correct diagnosis was made cytologically in 92.5% of patients with hepatic malignancy and in 89.5% of those from whom histologic material was obtained. From a combination of histologic and cytologic results, the overall diagnostic rate for hepatic malignancy was increased to 95%. This procedure proved to be a reliable method for diagnosis of hepatic malignancy.

Biopsy, Needle↗