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Biomedical subjects

T Hitoshi

Publications and source records attributed to T Hitoshi.

At least 19 recordsLinked to original sources

Acute accidental overdosage of haloperidol in children.

We report the details of an accidental overdosage of haloperidol in 24 children in one hospital in Kyushu, Japan. Evidence of acute toxicity included disturbances in consciousness (24/24), tremors in the extremities (16/24), an oculogyric or similar crisis (14/24), dysarthria (9/17), drooling (8/24), akathisia (6/20), hyperreflexia (6/24) and opisthotonos (3/24). Laboratory examinations revealed late-onset transient thrombocytosis (5/24), elevated AST and GPT (1/24) and abnormal ECG with prolonged QT interval in 2 of 8 children. We detected haloperidol in 11 of 18 children whose blood was specifically examined within four days after the final haloperidol administration. The maximum serum haloperidol level was 28.9 ng/ml. The mean half-life of haloperidol in the serum of five children (age range 2-10 years) was 18.6 +/- 12.2 h (mean +/- SD) (range 9.1-39.4 h).

Acute Disease↗

[Neurotoxicity of allyl chloride in rats. Dose-effect relationship following long-term exposure].

To elucidate the dose-effect relationship of neurotoxicity of allyl chloride (AC) in Donryu rats, 5 animals each were exposed to 10, 50 and 100 ppm AC for 8 h/d and 5 d/wk for a period of 34 wk. Nerve conduction velocities of the tail nerve in rats were determined before and after 4, 8, 12, 16, 22, 28 and 34 wk of exposure, and the width of landing foot-spread after 8, 12, 16, 28 and 34 wk. Animals subjected to 100 ppm AC showed significant (p less than 0.01) reduction of motor and sensory nerve conduction velocities and nerve action potentials (NAP) after 28 wk when clinical signs of neuropathy were observed, i.e., weakness of hindlimbs and significantly (p less than 0.01) extended landing foot-spreads. Motor distal latency was retarded in rats exposed to 100 ppm AC at the last period of exposure. In rats exposed to 50 and 100 ppm AC, no remarkable electrophysiological findings or abnormal clinical signs were observed except for depressed amplitude of NAP in 50 ppm-exposed rats when compared with those exposed to 10 ppm.

Action Potentials↗

[Chemotherapy with Cisplatin-Phosphatidyl-choline-Lipiodol (CPL) suspension in unresectable hepatocellular carcinoma].

Twenty-seven patients with unresectable hepatocellular carcinoma (HCC) were treated with Cisplatin-Phosphatidyl-choline-Lipiodol (CPL) suspension. PR was obtained in two of ten cases (20%) by one shot therapy. AFP decreased in 9 of 10 patients by one shot therapy with a 62.1% rate of decrease. In all of 13 patients by TAE, AFP decreased and the rate of decrease was 64.8%. The concentration of CDDP in the peripheral venous blood was lower and continued longer than that of CDDP on the market. Nausea, vomiting and fever were noted in most cases as adverse effects, but they were slight. These results suggest that CPL agents were very chemotherapeutic for unresectable HCC.

Carcinoma, Hepatocellular↗

Identification and quantification of 5-hydroxypipecolic acid and hydroxyproline in mammalian brain and blood by selected ion monitoring.

A method for the analysis of 5-hydroxypipecolic acid and 4-hydroxyproline in mammalian brain and blood is reported. The identification and quantification of the two hydroxyimino acids were accomplished with gas chromatography/mass spectrometry including a selected ion-monitoring technique following HPLC prepurification. The lower limit of detection for the method is 2 to 10 pmol. The amounts of 5-hydroxypipecolic acid and 4-hydroxyproline in blood were 20 to 30 pmol/ml and 3 to 6 nmol/ml, respectively. Their concentrations in the rabbit whole brain were determined to be 5 and 120 pmol/g, respectively.

Adult↗

Pipecolic acid enhancement of GABA response in single neurons of rat brain.

Using unit recording and microelectrophoresis, influence of pipecolic acid (PA), a major metabolite of lysine in the brain, on GABA and glycine responses was studied in the cerebral cortical and hippocampal pyramidal neurons of rats. With small currents, PA had no effect on the single neuron activities but enhanced GABA response without affecting glycine response. The finding provides a new evidence that PA may have a connection with central GABA system.

Action Potentials↗

Effects of vitamin B12 and B6 on 2,5-hexanedione-induced neuropathy.

The therapeutic effect of Vitamin B12 or Vitamin B6 on 2,5-hexanedione induced-neuropathy in animals was examined by using our electrodiagnostic technique in order to investigate the mechanism of the development of the neuropathy. Pyridoxal phosphate and two forms of Vitamin B12 were administered to rats intoxicated by the neurotoxin for a period of 18 weeks, and the sensory and motor fiber conduction velocity and the motor distal latency of the tail nerve were periodically determined. None of the groups treated with the therapeutic drugs exhibited a definite improvement in the nerve fiber conduction velocity and motor distal latency of the rat tail nerve, as compared with those of the 2,5-hexanedione-treated controls.

Animals↗

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↗

[Pharmacokinetics of cisplatin and the effect of sodium thiosulfate].

The pharmacokinetics of cisplatin (cis-dichlorodiammineplatinum (II), CDDP) have been studied in 11 patients. Plasma and urine CDDP concentrations were determined by flameless atomic absorption spectrophotometry. The treatment schedule was administered either by a 3-hour and 4-hour i.v. infusion or a 1.5-hour i.a. infusion. In the 3-hour i.v. infusion, the peak level of plasma total CDDP was 4.09 micrograms/ml after the end of infusion and non-protein-bound CDDP was 0.78 microgram/ml. Plasma total CDDP level declined with two peaks, the half-life of the alpha phase being 3.3 hours and that of the beta phase being 5.29 days. The half-life of non-protein-bound CDDP was 1.6 hours. CDDP might have remained for a long time, because CDDP values were obtained 3 weeks after infusion and urinary recovery of CDDP showed low values. Its urinary recovery was 40.3% of the dose infusion in the first 24 hours and 48.0% in 96 hours. The protein-binding of CDDP was inhibited by sodium thiosulfate(STS) and renal urinary excretion was enhanced. Our data suggest that STS can be applied as a neutralizer of CDDP.

Cisplatin↗

Pharmacological studies on dl-glaucine phosphate as an antitussive.

Antitussive effect, toxicity and other related pharmacological properties of dl-1,2,9,10-tetramethoxy-6a,alpha-aporphine phosphate (dl-glaucine phosphate, DL-832) were studied in comparison with those of codeine. Acute toxicity of DL-832 in mice was 2/5 to 7/10 of that of codeine for any routes of i.v., i.p., s.c. and p.o. The antitussive effect as tested by "coughing dog and cat" methods and Domenjoz's method in cats was 1/5 to 4/5 that of codeine, according to the routes administered. Safety margin in antitussive effect was similar to or less than that of codeine. Differing from codeine, levallorphan exerted no influence on the antitussive effect of DL-832. In vitro, DL-832 exerted moderate relaxant actions on normal tone and on contractions induced by histamine and acetylcholine of tracheal muscle. In vivo, it showed a moderate relaxant effect on histamine-induced bronchial constriction. The decrease in the volume of respiratory tract fluid caused by DL-832 was smaller than that by codeine. DL-832 slightly reduced the transportation rate of intratracheal foreign body, although to much lesser extent as compared to codeine. On respiration, blood pressure and heart rate, DL-832 showed depressant effects and moreover it caused changes in ECG. However, all of these effects were similar to and a little weaker than those observed with codeine. DL-832 prolonged hexobarbital sleeping time significantly. Neither analgesic nor anticonvulsant effect was observed. When given in larger doses, DL-832 inhibited intestinal transportation in vivo, although this effect was much weaker than that of codeine. DL-832 showed slight local anesthetic effect.

Anesthetics, Local↗

On the sites of antitussive action of dl-glaucine phosphate.

The sites of antitussive action of dl-1,2,9,10-tetramethoxy-6a,alpha-aporphine phosphate (dl-glaucine phosphate, DL-832) were studied. It was assumed from the following results that DL-832 acts on the cough center per se. a) When DL-832 was given by the routes leading to the brain stem such as the vertebral artery and the cerebello-medullary cistern, far smaller doses were sufficient to obtain the same effect as that by i.v. administration. b) DL-832 showed neither effect on the afferent pathway for cough reflex nor influence on pulmonary stretch receptors. c) It exhibited practically no influence on the efferent pathways for cough reflex, that is, that for innervating respiratory muscle movement as well as that for controlling bronchial muscle tone. d) Decerebration exerted no influence on the antitussive effect. e) DL-832 definitely depressed the potentials of both the recurrent and internal intercostal nerves evoked by the superior laryngeal nerve stimulation. f) In deafferentated and decerebrate cats, DL-832 rather increased the spontaneous discharges of the phrenic nerve, whereas codeine decreased them.

Afferent Pathways↗

Analysis of endogenous pyrrolidine levels by mass fragmentography.

Pyrrolidine, one of biogenic volatile amines, possesses nicotine-like synaptotropic actions on the nervous systems. In the present study, pyrrolidine levels in the tissues were examined by using mass fragmentographic technique. High concentrations of pyrrolidine were found in the seminal vesicle and lung of rabbits. Only trace amounts of pyrrolidine existed in the brain of mice and rats, although higher concentrations were detected in the brain of rabbits. In the rat brain, however, high levels of pyrrolidine were found in the pineal gland, pituitary gland and corpus striatum.

Animals↗

Potentiation of phenobarbital-induced anticonvulsant activity by pipecolic acid.

Pipecolic acid (PA) is an intermediate of lysine metabolism in the mammalian brain. Recent findings suggest a functional connection of PA as neuromodulator in GABAergic transmission. Since many drugs are postulated to produce their effects by interaction with the central GABA system, the influence of PA on the anticonvulsant activity of phenobarbital was examined. Pretreatment of mice with 50 mg . kg-1 of PA potentiated the suppressing effects of the barbiturate on electrically and chemically induced convulsions. However, there was no potentiation of the behavioral effects and hypothermia induced by phenobarbital. PA itself had no or only little effect on the convulsions, motor function and rectal temperature when given in i.p. doses up to 500 mg . kg-1. Intraventricular administration of 500 microgram of PA also did not suppress either type of convulsion, although it produced ptosis, hypotonia, sedation and hypothermia. The results are discussed in relation to GABA system.

Animals↗

Pipecolic acid: a new type of alpha-amino acid possessing bicuculline-sensitive action in the mammalian brain.

Using unit recording and electrophoretic techniques, pharmacological properties of pipecolic acid (PA) were studied in the brain neurons of rats. PA response was blocked by bicuculline more effectively than GABA response but not blocked by strychnine. Stereochemical findings obtained using the HGS-model demonstrated that PA structure is almost the same as a part of bicuculline structure. The present results suggest that PA might be a new type of substance possessing bicuculline-sensitive action. The site of the action of PA was also discussed.

Animals↗

Changes in brain piperidine levels under anesthesia: mass fragmentographic analysis.

Piperidine is a biogenic alicyclic amine possessing potent pharmacological activity. Interest has recently been focussed on its possible role as an endogenous hypnogenic substance. Using a mass fragmentographic technique with deuterium-labelled piperidine as an internal standard, the time relations of the change in brain levels of piperidine and the anesthetic activity of urethane were determined in mice. The brain piperidine level increased prior to the loss of the righting reflex and the elevated level declined prior to the reappearance of the reflex. The change in brain piperidine level correlated with neither that in spontaneous motility nor that in body temperature. The findings favor the idea that piperidine might at least partly regulate the level of consciousness.

Anesthesia↗

A new method for evaluating mucolytic expectorant activity and its application. II. Application to two proteolytic enzymes, serratiopeptidase and seaprose.

Using our new method described in a preceding paper, in vivo effects of two proteolytic enzymes such as serratiopeptidase (SER) and seaprose (SAP) on sputa collected from bronchitis rabbits were examined. SER (20 mg/kg) and SAP (30 mg/kg) significantly reduced the viscosity of sputum (P less than 0.05) at the 1-3-h periods and the 4-6-h periods, respectively, after intraduodenal administration. 50 mg/kg of SER also significantly decreased not only viscosity (P less than 0.001) but also amount of freeze-dried substance (P less than 0.05) of sputum at the 1-3-h periods, but SAP did not affect the amount of dried substance. Both enzymes significantly increased the volume of sputum, probably as the result of liquefaction. Thus, mucolytic expectorant activity of both enzymes can be demonstrated first by the reduction in viscosity and next of the increase in volume of sputa. However, the decrease in amount of freeze-dried substance is not always in accord with the reduction viscosity.

Animals↗

A new method for evaluating mucolytic expectorant activity and its application. I. Methodology.

A new method for evaluating in vivo effect of mucolytic expectorants was devised. In this report, however, the focus is placed on methodology but not on pharmacology. Rabbits with subacute bronchitis were prepared by long-term exposure to minute amounts of SO2 gas. The sputum was quantitatively collected from the animal through a tracheal cannula at suitable time intervals according to the Perry and Boyd's method. As a preliminary study, changes in volume, viscosity and amounts of freeze-dried substance of sputa were examined after intraduodenal administration of water instead of mucolytic expectorants, the effects of which will be described in the subsequent paper, but no significant changes occurred with this test.

Animals↗

Effects of anesthetics on piperidine levels in mouse brain.

Piperidine is one of the biogenic amines possessing potent pharmacological activity. Recent interest has focused on its possible role as an endogenous hypnogenic substance. Using a mass fragmentographic technique with deuterium-labelled piperidine as an internal standard, piperidine concentrations in brains of waking and deeply anesthetized mice were analyzed to compare piperidine levels in the brain under distinctly different states of consciousness. A rapid and significant increase in piperidine concentrations was found in the brain but not in blood of mice anesthetized with any one of pentobarbital, urethane, ether and halothane. The results, showing that CNS depression is accompanied by accumulation of piperidine in the brain, are consistent with the idea that piperidine may have a close connection with the mechanisms controlling the level of consciousness.

Anesthetics↗