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Biomedical subjects

T Yoshii

Publications and source records attributed to T Yoshii.

107 records · Page 6Linked to original sources
PubMed1983

[Effect of methamphetamine on morphine preference].

The effect of methamphetamine on preference for morphine was studied in rats by the drug-admixed food (DAF) method. The preference rates for morphine-admixed food gradually increased by the repetition of choice and forced trials and then became stable at the level of 70%. On the other hand, the preference rates for morphine-admixed food combined with methamphetamine did not so increase compared with the case of morphine alone. From the taste aversion test, it was assumed that combination of morphine and methamphetamine did not enhance taste aversion, although methamphetamine suppressed development of preference for morphine. In the case of combination of morphine and cocaine or caffeine, preference rates for these drugs increased like the case of morphine. This result indicated that the suppression of the preference for morphine which was induced by methamphetamine was not produced by the general effect of CNS stimulants. We found that methamphetamine suppressed the development of the preference for morphine. These findings suggest that the suppression resulted from neither taste aversion nor the general effect of CNS stimulants. Furthermore, acute toxicity and other effects were enhanced by the combination of morphine and methamphetamine, and it might participate with the suppression.

Animals↗
PubMed1982

[Plasma corticosterone concentration in morphine-dependent rats].

The effects of morphine on plasma corticosterone concentration in rats were studied using the drug-admixed food method. Morphine was mixed with the powder form of rat food in concentrations of 0.5 mg/g, 1 mg/g, and 2 mg/g of food. Plasma corticosterone concentration in rats treated with morphine-admixed food increased significantly, and the increment depended on the morphine concentration of drug-admixed food. The time course change of plasma corticosterone concentration in rats treated with morphine-admixed food (1 mg/g food) for 1 week was similar to that of non-treated rats without the concentration at 9:00. The plasma corticosterone concentration of morphine-treated rats at 9:00 was significantly increased in comparison with that of non-treated rats. Furthermore, the plasma corticosterone concentration after withdrawal in morphine-treated rats increased with time, and a significant increment in corticosterone was observed at 24 hr after the withdrawal. Naloxone, injected subcutaneously into morphine-dependent rats, significantly increased plasma corticosterone concentration. Increment of plasma corticosterone concentration in rats treated with morphine-admixed food for 3 or 4 weeks was significantly different from the non-treated group. The increment of plasma corticosterone concentration after the withdrawal was in a morphine treatment period-related manner. By these results, we suggest that tolerance to the increment action in plasma corticosterone concentration of morphine does not develop for at least 4 weeks using the drug-admixed food method, and the drug-admixed food method could induce morphine dependence without disturbance of the circadian rhythm in plasma corticosterone.

Animals↗
PubMed1981

[Effects of morphine on the successive generation].

The preference and physical dependence for morphine, changes in gross behaviors and growth were investigated in the offspring of pregnant rats treated with morphine. Six groups (A-F) of the pregnant rats were treated with morphine by DAF (drug-admixed food) method for the following periods. No morphine-treatment was received in group A, treatment form the beginning of pregnancy (day 0) to weaning in group B, from day 0 to day 14 in group C, from day 15 to day 21 in group D, from day 0 to weaning in group E (the same of B), and no treatment in group F. The pups of group E were fostered to maters of group F, and pups of group F, and pups of group F were to maters of group E. The preference rate for morphine in pregnant rats increased significantly in comparison with of non-pregnant rats. Weanling rates of group B, C, D and E decreased significantly when compared with that of group A. The pups of maternal rats treated with morphine showed hyperactivity and vocalization. These symptoms were considered to be resulted from the withdrawal signs. The withdrawal signs may produce the decrease in the weanling rates. There was no difference in body weight gains in the offspring between group A and B. Preference rate for morphine in the offspring of group B was lower than that of group A. It may be due to an enhanced susceptibility to morphine in group B. However, no marked change in intensity of physical dependence on morphine was detected in the offspring between group A and B.

Animals↗
PubMed1981

[The quantitative evaluation of the preference for morphine by rats (author's transl)].

We examined the quantitative evaluation of preference for morphine by assessing the conflict behavior between positive motivation and negative motivation. The apparatus consisted of a single runway in which both the usual diet and morphine-admixed food were placed. For access to the latter, the rats were compelled to pull heavy weights which were connected to their necks. During the forced trials (only morphine-admixed food was given) and the choice trials (rats could select either food), the preference rates gradually increased and then became stable at levels of 60%. After these trials, experiments on conflict behavior were performed using several different weights. Assessment of relation between the intensity of the dependence on the drug and the degree of weight showed a good correlation. We conclude that the preference for a drug can be quantitatively measured by means of assessing conflict behavior.

Animals↗
PubMed1980

Effect of p-chlorophenylalanine on diazepam withdrawal signs in rats.

The effect of p-chlorophenylalanine (PCPA), a specific serotonin (5-HT) depleter, on diazepam withdrawal signs was studied. Rats were made dependent on diazepam by the chronic administration of this drug in the diet. At the time of diazepam withdrawal, the animals were treated with PCPA (200 mg/kg, IP) or the corresponding vehicle (control). After diazepam withdrawal, the maximal body weight losses of control and PCPA-treated animals were 4.1% and 9.0%, respectively. In naive animals, PCPA did not cause any change in body weight. These results suggest that depletion of central 5-HT by PCPA may potentiate the severity of diazepam withdrawal signs.

Animals↗
PubMed1978

Differential inhibitory effects of 5-bromodeoxyuridine on vaccinia and monkeypox viruses.

Replication of vaccinia and monkeypox viruses was impeded in the presence of 5-bromodeoxyuridine (BUdR) in RL-33 cells derived from rabbit lung tissue. The different degree of inhibition was found among strains of those viruses, in which it was evident that five strains (CV-1, Lister, IHD, Dairen-I and Ikeda) of vaccinia viruses resulted in more reduced yields of infectious virus than four strains (Sen-19, Orang Utan, Copenhagen and Sierra Leone) of monkeypox viruses. There was also strain variation in BUdR sensitivity within vaccinia viruses but not in the case of monkeypox viruses.

Bromodeoxyuridine↗
PubMed1978

Optimal conditions for plaque assay of echoviruses in human embryonic lung fibroblast cells.

The present paper gives optimal conditions for plaque assays tn human embryonic lung fibroblast cells with 45 echoviruses including 11 fresh isolates, covering 31 serotypes. All the viruses tested except echovirus type 23 produced plaques at a high titer in the same cells by the methods described in this communication. Plaque formations by a number of strains were markedly enhanced in size or number or both by the addition of polycation.

Cell Line↗
PubMed1977

Replication of enterovirus 70 in non-primate cell cultures.

Replication of the strain J 670/71 of enterovirus 70 (EV70) in non-primate cell cultures at 33 degrees C was studied using strain L (mouse), BHK21 (hamster), RK13 (rabbit), RK17 (rabbit), PK15 (porcine), IB-RS-2 (porcine), ESK (porcine), MDBK (bovine), and BK1 (primary bovine) together with that of the LSc, 2ab strain of poliovrus type 1 (PV1) as a control. All the cells tested adsorbed from 54 to 90% of EV70. The replication with complete c.p.e. was evident in RK13, RK17 and BK1 cells; replication without c.p.e. was shown in L, BHK21, IB-RS-2 and ESK; but PK15 and MDBK were non-permissive despite a high virus adsorption rate. On the contrary, none of these non-primate cells allowed the adsorption and growth of PV1. One-step growth of EV70 in RK13 was almost identical with that in the primate cells. Two other strains of EV70 were found having similar host range in vitro. Therefore, it is concluded that EV70 has a wider host range in vitro than ordinary human enteroviruses, and its implication is discussed.

Adsorption↗
PubMed1977

Phenylalanine hydroxylase deficiency in the peripheral lymphocytes from phenylketonuria.

A radiograph of the incorporation of 3H-phenylalanine and 3H-tyrosine into cultured lymphocytes in a phenylketonuria patient indicates phenylalanine hydroxylase deficiency in the peripheral lymphocytes. Cultured lymphocytes from the patient showed much less uptake of 3H-phenylalanine and a slightly higher incorporation of 3H-tyrosine than the control. It is possible that a lack of phenylalanine hydroxylase in the peripheral lymphocytes of PKU patients prevents oxidation of phenylalanine to tyrosine.

Autoradiography↗
PubMed1977

Establishement of a rabbit lung cell line (RL-33) and its viral susceptibility.

A new cell line (RL-33) was established from a rabbit lung tissue. The cells maintained a fibroblastic appearance and a contract-inhibited growth through 180 passages. No latent infectious agent has so far been demonstrated. The cells supported the growth of a variety of viruses, enabling plaque assays for Shope fibroma, rabbit myxoma and types 1 and 2 herpes simplex viruses. They were as sensitive to rabbit interferon as RK-13 (a line from rabbit kidney) cells.

Animals↗
PubMedDate not supplied

A study of the evolution of coxsackievirus A24 variant in Ghana by viral RNA fingerprinting analysis.

An epidemic of acute haemorrhagic conjunctivitis (AHC) caused by coxsackievirus A24 variant (CA24v) was reported in Accra, Ghana in May 1987. We studied 7 of the viral strains collected from May to November, 1987, by RNA genome fingerprinting. Pairwise comparisons of the oligonucleotide maps showed that genetic similarity among them ranged from between 60.0 to 84.7%. Using base sequence variations deduced from genetic similarity among the isolates, isolation time of the strains and the rate of nucleotide substitution (estimated in a previous paper, Miyamura et al., 1990), we calculated divergence times and constructed a phylogenetic tree. This tree indicated that all the 7 strains had diverged from each other from 11 to 26 months before the AHC epidemic in Accra. CA24v may have been introduced into the country or the neighbouring area, at least, more than two years earlier, i.e. in the early half of 1985.

Adult↗