Biomedical subjects
H Yoshimura
Publications and source records attributed to H Yoshimura.
[Therapeutic effect of paromomycin sulfate in the treatment of Diphyllobothrium latum infections and an observation on the worm tissues affected by the drug].
Paromomycin sulfate (aminosidine) at a single dose of 32 to 53 mg/kg was orally given to 24 cases with proven diphyllobothriasis. Evaluation of efficacy of the drug was based on stool examination for the eggs after 3--4 weeks of treatment. The cure rate was obtained as 96% (23/24), and 30 worms were expelled from 24 patients. Only 1 unsuccessfully treated case of 34-year-old man was retreated at the same dose of the drug 3 weeks later to obtain the cure. Thirty worms were composed of a single worm each from 21 patients, 2 worms from a patient, 3 from 1, and 4 from 1. Scolices of 7 (23.3%) out 30 worms were found. Vomiting as side effect of the drug was observed in only a case of 4-year-old girl at 40 minutes after administration of the drug but it was mild and transient. Clinical symptoms or complaints before treatment were as follows; abdominal discomfort in 12 cases, abdominal pain in 7, diarrhea in 4, fatigue in 2, tinnitus, vomiting and frequent stool in 1 each. Seven cases were almost asymptomatic. Morphological changes of the worms immersed in paromomycin solution (aminosidine) (1.66 mg/ml) for 1, 2 and 3 hours were observed in comparison with worms kept in physiological saline solution. The destructive effects were fragmentation, dissolution and desquamation of the outer cuticle and basement membrane with PAS stain at 3 hours of the experiment. The damages were also demonstrated in subcuticular tissues composing of muscle layer and parenchymal cells.
[Synthesis of 14C-2,3,4,7,8-pentachlorodibenzofuran].
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[Clinico-pathological study of gastric cancer in the greater curvature].
Among 3727 gastric cancer patients, the cancer was located in the greater curvature in 9.2%; 62 of 1060 patients (5.8%) had early cancers. The average age of patients with gastric cancer in this area was somewhat higher compared with that of all gastric cancer patients. In early cancers of this area, the incidence of intestinal type carcinomas was more frequent than in patients with early cancers of the other area. However, in advanced cancer of this area, the incidence of diffuse type carcinoma was higher than in advanced cancers of the other area. The incidence of early cancer measuring more than 5 cm in diameter was 4.8% (15.5% for all early gastric cancers). The incidence of mucosal cancer was 33.8% (53% for all early gastric cancers).
8 alpha, 9 alpha-Epoxyhexahydrocannabinol formation from delta 8-tetrahydrocannabinol by mouse liver microsomes.
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Difference in tolerance development of hypothermia and pentobarbital-induced sleep prolongating effect of 11-hydroxy-delta 8-tetrahydrocannabinol and 11-oxo-delta 8-tetrahydrocannabinol in mice.
Daily administration (5 mg/kg i.v.) of 11-hydroxy-delta 8-tetrahydrocannabinol or 11-oxo-delta 8-tetrahydrocannabinol as well as delta 8-tetrahydrocannabinol quickly induced tolerance to their hypothermic effects in mice. Tolerance also developed to their pentobarbital-induced sleep prolongating effects. However, the degrees of tolerance development differed from one another. The sleeping times after the 8th injection of these cannabinoids were still significantly longer than those of the controls when no hypothermia was induced.
Disruption of primate social behavior by d-amphetamine and cocaine: differential antagonism by antipsychotics.
Psychostimulants lead to withdrawal from social interactions and to a decline of affective behavior in squirrel monkeys. These changes, in addition to motor stereotypies, may be related to stimulant-induced psychosis in humans. In the first of two series of experiments, 1 mg/kg d-amphetamine or 10 mg/kg cocaine, administered orally three times over 24 h to one adult male member of an established group (n = 6-9), engendered stereotyped movements of the head and hands, reduced rest postures, and greatly reduced all forms of social initiatives. Chlorpromazine (0.25-1.0 mg/kg), haloperidol (0.25, 0.5 mg/kg), and physostigmine (0.04, 0.08 mg/kg), administered before the third amphetamine or cocaine injection, blocked the motor stereotypies and hyperactivity. Chlorpromazine, haloperidol, and physostigmine did not reliably antagonize the pronounced reduction in social behavior. The second series of experiments focused on agonistic behavior in the context of resident-intruder confrontations and on affiliative behavior toward group members. d-Amphetamine (3 X 0.5 mg/kg) and, to a lesser extent, cocaine (3 X 10 mg/kg) decreased affiliative and agonistic behavior. Chlorpromazine (0.5, 1.0 mg/kg) and haloperidol (0.1, 0.25 mg/kg) did not block the severe disruption of the affiliative and agonistic behavior in amphetamine-treated monkeys; physostigmine (0.06 mg/kg) reversed the decline in time spent close to the familiar monkey in amphetamine-treated monkeys. By contrast, stimulant-induced stereotypies were effectively antagonized by chlorpromazine, haloperidol, and physostigmine. These results suggest that psychostimulant-induced changes in primate social behavior may be mediated by mechanisms other than those underlying motor stereotypies.
Studies on enzymatic reduction of aliphatic nitro compounds: reductive dimerization of beta-nitrostyrene and 1-nitro-4-phenylbutadiene.
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The binding of myosin subfragment-1 to F-actin in the absence of nucleotide. Evidence for dependence on F-actin concentration.
The binding of myosin subfragment-1 (S-1) to F-actin in the absence of nucleotide was examined by the sedimentation method using 1,5-IAEDANS-labeled S-1. We found that the binding affinity of F-actin to S-1 was dependent on the concentration of F-actin, and the binding was weaker at higher concentrations of F-actin. The apparent association constant determined from a linearly extrapolated Scatchard plot was 6.5 x 10(6) M-1 at 8.1 microns F-actin, and 1.7 x 10(7) M-1 at 2.0 microns F-actin in 120 mM KC1, 2 mM MgCl2, 0.1 mM CaCl2, and 20 mM Tris-acetate (pH 7.6) at 20 degrees C. Furthermore, the Scatchard plot revealed the existence of cooperativity in the binding of S-1 to F-actin. In order to obtain higher precision we developed a new method for the chromatographic determination of free S-1 in acto-S-1 solution. By this method we could determine free S-1 concentrations of the order of 10(-9) M easily and accurately. The above conclusion obtained by the sedimentation method was confirmed by this chromatographic method, and these effects can be well explained by considering the length distribution of F-actin. We propose an allosteric model in which both the length distribution and the polarity of F-actin are taken into consideration.
Decreased urinary excretion of thiamine propyl disulfide metabolites in patients with liver disease.
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A novel metabolite of oxycodone in the urine of rabbits.
In addition to six metabolites of oxycodone which were reported previously, 7 beta-hydroxy-6 beta-oxycodol was further isolated as one of the major metabolites in rabbits. The structure of this novel metabolite was characterized by mass and nuclear magnetic resonance spectra. Such a metabolite possessing vicinal hydroxyl groups in aliphatic ring is very new in the metabolism of narcotic analgesics.
Oxygen--insensitive nitrofuran reductases in Salmonella typhimurium TA100.
The present study demonstrated by DEAE-cellulose column chromatography that oxygen-insensitive nitrofuran reductases in Salmonella typhimurium TA100 consisted of at least two reductases, NADPH- and NAD(P)H-linked enzymes. The NADPH- and NADH-linked activities of the latter enzyme seemed to originate from a single enzyme, because both activities were similarly inactivated by heat and urea treatments, and also inhibited by dicumarol. On the other hand, the NADPH-linked enzyme was less sensitive to heat, urea and dicumarol. Furthermore, the study showed that the NAD(P)H-linked enzyme was a flavoenzyme which could be inactivated by dialysis against 1 M potassium bromide and reactivated by FMN.
Determination of oxycodone metabolites in urines and feces of several mammalian species.
Determination of oxycodone metabolites excreted in urines and feces of several mammalian species was studied by use of the tritium labeled compound. It was found that the radioactivity was excreted more in the urines than in the feces in rabbits, guinea pigs and mice, but not in rats, who eliminated it equally into the urines and feces. Most of the radioactivity was excreted in 48 h after the administration. Seven metabolites, oxymorphone, 6 alpha-oxycodol, 6 beta-oxycodol, 7 beta-hydroxy-6 beta-oxycodol, noroxycodone, oxycodone N-oxide, and 6 alpha-oxycodol, N-oxide, as well as well as unchanged oxycodone, were found to be excreted into urines of rabbits in both free and conjugated forms except two N-oxides, which were found only in the free form. It was discussed that analgesic effect of oxycodone would mainly be attributable to the oxycodone itself, but not to the metabolites.
Enhancement of sulfanilamide N4-hydroxylase activity in kidney and liver microsomes of rats by pretreatment with 3-methylcholanthrene type-polychlorinated biphenyl.
N4-Hydroxylation of sulfanilamide was studied with kidney and liver microsomes of rats by means of high performance liquid chromatography. In kidney microsomes, both contents of cytochrome P-450 (448) and activity of N4-hydroxylase were markedly increased by pretreatment with 3,4,5,3',4'-pentachlorobiphenyl (PenCB) (about 4 times), although neither one was increased by 3-methylcholanthrene (3-MC) and phenobarbital (PB) pretreatments. In liver microsomes, on the other hand, both N4-hydroxylase activity and cytochrome P-450 (448) contents were increased by either PenCB or 3-MC pretreatment, whereas by PB pretreatment, N4-hydroxylase activity was not changed although cytochrome P-450 contents was increased 2-fold.
Determination of urinary metabolites of thiamine propyl disulfide in humans.
Gas chromatographic procedure for the quantitative determination of methyl propyl sulfone (MPS), 2-hydroxypropyl methyl sulfone (2HPMS) and 3-hydroxypropyl methyl sulfone (3HPMS) in urine was developed. By using this procedure, the urinary excretion of MPS, 2HPMS and 3HPMS after oral dose of thiamine propyl disulfide (TPD) was investigated in healthy adults, in order to assess their ability of drug disposition including metabolism. Among these metabolites, 2HPMS was predominant and the other two were minor. 2HPMS was excreted most in the 24--36 h urine and the time course of excretion of this metabolite was almost the same among these subjects. In 4th day urine, a significant amount of 2HPMS was still excreted. On the contrary, the time course of excretion of MPS varied among subjects and also at different occasions in the same subjects. 3HPMS was excreted most in the 0--12 or 12--24 h urine and more rapidly excreted than 2HPMS. Two-fold interindividual differences in the amount of 2HPMS in the 0--48 h urine occurred and intraindividual difference was also observed. Inter- and intraindividual differences in the amount of MPS in 0--48 h urine were much larger than that in 2HPMS. In 3HPMS, these differences were slightly less than in 2HPMS. Sex difference in the excretion of MPS and 2HPMS was not observed.
A unique change of steroid metabolism in rat liver microsomes induced with highly toxic polychlorinated biphenyl(PCB) and polychlorinated dibenzofuran(PCDF).
Pretreatments of rats with the highly toxic compounds such as 3,4,5,3',4'-pentachlorobiphenyl(PenCB), and 2,3,7,8-tetrachloro(TCDF) and 2,3,4,7,8-pentachlorodibenzofuran(PenCDF), which are potent 3-methylcholanthrene(MC)-type inducers, increased selectively 7 alpha-hydroxylation, but strongly suppressed 2 alpha-, 6 beta- and 16 alpha-hydroxylations as well as 5 alpha-reduction of progesterone and testosterone in the liver microsomes. This unique change in the metabolic pattern was accompanied by a marked decrease in total metabolism of both steroids and appeared to correlate apparently with their toxic potency. This kind of change was not shown by pretreatments with not only MC itself but also the phenobarbital-type(2,4,5,2',4',5'-hexachlorobiphenyl) and the mixed type PCBs(Kanechlor 400, a PCB mixture with 48% chlorine content), all of which possess only a low acute toxicity. The metabolic change produced by 3,4,5,3',4'-PenCB, 2,3,7,8-TCDF and 2,3,4,7,8-PenCDF might not be due to their stimulatory or inhibitory effects, because when added to the incubation mixture 3,4,5,3',4'-PenCB did not change the metabolic pattern with MC-microsomes to that with 3,4,5,3',4'-PenCB-microsomes. Furthermore, either 2,3,7,8-TCDF or 2,3,4,7,8-PenCDF gave similar metabolic pattern whereas their residual levels in the liver were greatly different from each other at the time of sacrifice. These results suggest that this kind of unique change of the steroid metabolism produced by highly toxic PCBs and PCDFs may be responsible, at least in part, for the endocrine symptoms caused by these compounds via disturbance of steroid homeostasis.
Reduction of methyl 5-nitro-2-furoate by xanthine oxidase: an evidence for hydroxylaminofuran formation.
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Pharmaco-ethological analysis of agonistic behavior between resident and intruder mice: effect of anticholinergic drugs.
The resident-intruder paradigm was employed in order to evoke an agonistic behavior in mice. In this situation a resident male mouse has been cohabiting with a female for 5 weeks, and an intruder male mouse is introduced into the resident's home cage. A species-specific pattern of agonistic behavior was observed in all mice. The significance of cholinergic mechanisms in the mediation of the agonistic behavior was evaluated by pharmacological manipulations. Drugs were administered to resident mice. Scopolamine hydrobromide (0.25, 0.50 and 0.75 mg/kg, i.p.) significantly suppressed the resident's aggressive episodes (offensive sideways posture, tail rattling and attack biting) in a dose-dependent manner, whereas the peripheral anticholinergic drug methylscopolamine nitrate (0.25, 0.50 and 0.75 mg/kg, i.p.) was ineffective. On the other hand, the resident's locomotor activity and rearing response were significantly increased after the administration of scopolamine hydrobromide. The evidence suggests that brain cholinoceptive mechanisms may participate in the regulation of intraspecies aggressive behavior. However, it appears that other nonspecific behavioral effects of scopolamine cannot be ruled out.