Search PubMed⌕ Search

Biomedical subjects

F Kosaka

Publications and source records attributed to F Kosaka.

At least 37 records · Page 2Linked to original sources
PubMed1989

[The effect of succinylcholine on vecuronium and pancuronium].

In 105 adult patients under halothane anesthesia, the neuromuscular blocking effects of vecuronium and pancuronium were determined with prior succinylcholine 1 mg.kg-1 administration and without. Force of the evoked twitch increased 123.7% of control after recovery from succinylcholine-induced block. Prior administration of succinylcholine was associated with a leftward shift of dose-response curve of vecuronium or pancuronium. Onset of the force reduction from initial dose (0.08 mg.kg-1) was faster and recovery from initial and maintenance doses (0.02 mg.kg-1) were slower. This potentiating effect persisted at least 2 hours.

Adult↗
PubMed1989

[Usefulness of midazolam in a modified NLA--study on plasma concentrations].

Midazolam 0.2mg.kg-1 or diazepam 0.2mg.kg-1 was used as an induction agent in a modified NLA. Plasma concentrations of midazolam or diazepam were measured with benzodiazepines screen method, which was based on enzyme immunoassay. Pharmacokinetic analysis is based on the plasma concentration-time courses after a bolus injection. The distribution half-life (T alpha 1/2) of midazolam, 1.24 minutes, was shorter than that of diazepam, 3.85 minutes. The elimination half-life (T beta 1/2) of midazolam, 5.44 hours, was similar to that of diazepam, 5.02 hours. The initial fall-off in the alpha-phase was due to the distribution of the drug from plasma to the peripheral compartment, while the drop in the beta-phase was caused by redistribution from the peripheral compartment and total elimination of the drug. Midazolam was thought to be useful as an induction agent in a modified NLA, because midazolam is distributed to the peripheral compartment faster than diazepam. As midazolam has a long elimination half-life as that of diazepam, prolongation of its effects has to be considered when a large dose or continuous infusion is employed.

Adult↗
PubMed1988

Endotoxin-induced zinc accumulation by liver cells is mediated by metallothionein synthesis.

Endotoxin induces a decrease in zinc concentration in the serum and an increase in zinc levels in the liver. We have studied whether metallothionein (MT), which is a heavy metal-binding protein, is associated with this phenomenon in vitro. When MT of liver cells is induced by a factor secreted by endotoxin-stimulated macrophages, the cells accumulate zinc from the medium. The temporal accumulation of zinc is correlated with the induction of MT, and the accumulated zinc binds to MT. These results suggest that zinc accumulation by liver cells is mediated by metallothionein produced in response to a macrophage factor, which is elicited by endotoxin.

Animals↗
PubMed1988

Use of diltiazem to control circulatory fluctuations during resection of a phaeochromocytoma.

This report describes the use of diltiazem to control circulatory fluctuations during anaesthesia in five patients undergoing resection of a phaeochromocytoma. Diltiazem was administered continuously i.v. before anaesthesia and during surgery until the draining vein from the tumour had been ligated. Arterial pressure and systemic vascular resistance decreased in association with the infusion of diltiazem. Heart rate was stable, and there was no ventricular tachyarrhythmia. Arterial pressure was controlled easily during the manipulation of the tumour, and there were no hypotensive episodes after the removal of the tumour.

Adrenal Gland Neoplasms↗
PubMed1988

The influence of respiratory-induced acid-base changes on the action of non-depolarizing muscle relaxants in rats.

The influence of respiratory-induced acid-base changes on the action of non-depolarizing muscle relaxants was investigated using the rat phrenic nerve-hemidiaphragm preparation. Changes in pH were induced by changes in the CO2 concentration aerating Krebs' solution. In the absence of muscle relaxants, an increase in CO2 from 5% to 7.5% decreased (P less than 0.01) indirectly elicited twitch tension by 5.4 +/- 0.7% (mean +/- SEM), while a decrease in CO2 from 5% to 2.5% increased (P less than 0.01) twitch tension by 2.3 +/- 0.7%. With a change in CO2 from 2.5% to 7.5%, partial neuromuscular blockade produced by d-Tc or vecuronium was augmented (P less than 0.01), while that produced by metocurine, pancuronium, or alcuronium was reduced (P less than 0.01). With the change in CO2 from 7.5% to 2.5%, the neuromuscular blockade produced by d-Tc or vecuronium was reduced (P less than 0.01), while that produced by metocurine, pancuronium, or alcuronium was augmented (P less than 0.01). Dose-response study showed that 2.5% CO2 shifted the dose-response curves for d-Tc and vecuronium to the right (P less than 0.01) from those with 5% CO2, whereas 7.5% CO2 shifted them to the left (P less than 0.05). In contrast, neither 2.5% CO2 or 7.5% CO2 significantly shifted the dose-response curves for metocurine or pancuronium from those with 5% CO2. Their dose-response curves with 2.5% CO2 were to the left, instead of to the right, of those with 7.5% CO2 (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis, Respiratory↗
PubMed1988

Direct determination of the blood concentration of halogenated anesthetic agents by gas chromatography.

The direct determination by gas chromatography of blood levels of anesthetic agents has been difficult because of the water content of blood. In the present study, the method of Yokota et al. (1967) was modified by improving the packing materials of the column, the blood sample vaporizer and the flow-path during analysis. As a result, accurate and reproducible determination of halothane, enflurane and isoflurane dissolved in blood was achieved. With this system, blood in which halothane, enflurane and isoflurane had been dissolved could be analyzed without changing the column between samples. Moreover, each sample was prepared in less than 10 min, and more than 100 consecutive determinations could be made with excellent reproducibility. The coefficient of variation was less than 3.8%.

Chromatography, Gas↗
PubMed1987

Induction of metallothionein by a macrophage factor and the partial characterization of the factor.

The mechanism of metallothionein (MT) induction by lipopolysaccharide (LPS) was studied using an in vitro system. Rat peritoneal macrophages were incubated with or without LPS, after which the incubation medium was overlaid on human hepatic (Chang) cells. MT synthesis was induced in Chang cells treated with the macrophage medium incubated with LPS. No induction was observed when LPS was added directly to the Chang cell medium or when Chang cells were treated with the macrophage medium incubated without LPS. These results suggest that induction of MT by LPS is mediated by a factor released from macrophages. The factor is different from the known primary inducers of MT, such as heavy metals, glucocorticoid hormones, interleukin 1, and interferon. The factor is heat stable, nondialyzable, and stable at pH 2. Although its activity is lost by pepsin and trichloroacetic acid, it is resistant to trypsin.

Cells, Cultured↗
PubMed1987

Metallothionein and zinc metabolism in endotoxin shock rats.

Zinc metabolism in endotoxicosis was investigated in rats. The zinc concentration in the serum decreased, while zinc contents increased in the lung, kidney and liver. Marked increase in zinc level was observed in the liver. In the liver cells, zinc concentrations of mitochondria and cytosol increased, but not in microsome. Metallothioneins (MTs), which probably participate in zinc metabolism, were induced by endotoxin administration. Although the same level of MT-2 as that of MT-1 was induced by zinc, the level of MT-2 was 3 to 4 fold higher than that of MT-1 by administrations of endotoxin or glucocorticoid hormone. Since no metallothionein was induced directly by addition of endotoxin to the media of cultured cells, the endotoxin was found not to induce MTs directly. The effect of zinc on superoxide generation of polymorphonuclear leukocytes was also studied. Zinc was found to inhibit superoxide generation dose-dependently.

Animals↗
PubMed1987

Effects of halothane, enflurane and pentobarbital on brain histamine dynamics in mice.

The effects of halothane, enflurane, ketamine and pentobarbital on brain histamine dynamics were examined in mice. Brain histamine and tele-methylhistamine, a predominant metabolite of brain histamine, were simultaneously measured by high-performance liquid chromatography with fluorescence detection. Anaesthesia with the four agents had no effect on brain histamine content. The tele-methylhistamine content significantly increased during 1 h and 2 h anaesthesia with halothane (0.051 mmol/l or 0.76 mol/l) and 2 h anaesthesia with enflurane (0.11 mol/l or 0.16 mol/l). Enflurane and pentobarbital significantly inhibited the histamine depletion induced by alpha-fluoromethylhistidine (50 mg/kg, intraperitoneally), a specific inhibitor of histidine decarboxylase, suggesting that these agents decrease the histamine turnover. However, halothane and ketamine were ineffective in this respect. These results emphasize that various anaesthetics have different influences on brain histamine dynamics. Since there have been findings suggesting that brain histaminergic systems are involved in physiological functions such as regulation of blood pressure, body temperature and hormone secretion, changes in the brain histamine turnover should be given due attention with regard to physiological changes during anaesthesia.

Anesthetics↗
PubMed1987

Effects of ketamine on the cholecystokinin, somatostatin, substance P, and thyrotropin releasing hormone in discrete regions of rat brain.

Intraperitoneal injection of ketamine (100 mg/kg body weight) significantly reduces the levels of cholecystokinin (CCK), somatostatin (SRIF), and substance P (SP)-like immunoreactivity in various regions of rat brain. No significant change in thyrotropin releasing hormone (TRH)-like immunoreactivity was observed. Neuropeptide systems may be involved in the neuropharmacologic effects of ketamine.

Animals↗
PubMed1987

A resuscitation puzzle: acute acquired methemoglobinemia.

We treated a 32-day-old baby suffering acute acquired methemoglobinemia induced by topical application of aniline cocaine. Although acute acquired methemoglobinemia with severe cyanosis and distress is potentially fatal, this rare syndrome is easily curable if it is correctly diagnosed.

Anesthetics, Local↗
PubMed1987

Induction of metallothionein synthesis in cultured cells by substances released from endotoxin-activated macrophages.

The involvement of macrophages in the induction of metallothionein (MT) synthesis by bacterial endotoxin was studied in vitro. Rat peritoneal macrophages were incubated with endotoxin. The incubation medium from endotoxin-activated macrophages accelerated MT synthesis by human hepatic Chang cells. However, the incubation medium from non-activated macrophages did not. Endotoxin added to the culture medium of Chang cells was ineffective in inducing MT synthesis. The contents of zinc, copper and cadmium, which are primary inducers of MT, in the incubation medium of macrophages in the presence of endotoxin were not different from those in the absence of endotoxin. These results suggest that MT synthesis is induced by endotoxin-treated macrophages.

Animals↗