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Biomedical subjects

Y Sakurai

Publications and source records attributed to Y Sakurai.

At least 721 records · Page 40Linked to original sources
PubMed1977

N4-Behenoyl-1-beta-D-arabinofuranosylcytosine as a potential new antitumor agent.

N4-Acyl-1-beta-D-arabinofuranosylcytosines, which are lipophilic antitumor analogs of 1-beta-D-arabinofuranosylcytosine, were dissolved by the use of a detergent, HCO-60, and the differences in the antitumor activities when the drugs were administered in the forms of solution or suspension were compared. N4-Stearoyl-1-beta-D-arabinofuranosylcytosine (NSC 201290), which was the most active compound when administered as an aqueous suspension, diminished in its activities after it had been dissolved into a clear solution, whereas N4-behenoyl-1-beta-D-arabinofuranosylcytosine (NSC 239336) exhibited activities superior to those of the parent compound 1-beta-D-arabinofuranosylcytosine when administered as a solution. Moreover, the high efficacy of this compound was long lasting in the host animal, regardless of the treatment schedules or the presence of the 1-beta-D-arabinofuranosylcytosine-inactivating enzyme, cytidine deaminase.

Animals↗
PubMed1977

Comparative studies on the antitumor activity and the bone marrow toxicity of 1-(beta-D-glucopyranosyl)-3-(2-chloroethyl)-3-nitrosourea and 2-(3-(2-chloroethyl)-3-nitrosoureido)-D-glucopyranose.

Antitumor activity and bone marrow toxicity of a new nitrosourea analog, 1-(beta-D-glucopyranosyl)-3-(2-chloroethyl)-3-nitrosourea (GANU), were compared with those of 2-(3-(2-chloroethyl)-3-nitrosoureido)-D-glucopyranose (Chlorozotocin) and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). GANU was found to be highly active against mouse leukemia L-1210 when administered intraperitoneally or intravenously, being the same degree as Chlorozotocin. Even by oral route, GANU exhibited significant activities, whereas Chlorozotocin failed to show any activities by this route. Studies on the bone marrow toxicity as measured by the depression of white blood cell counts and the marrow cellularity revealed that both GANU and Chlorozotocin were less toxic than BCNU. GANU, however, weemed to be rather more toxic than Chlorotocin.

Administration, Oral↗
PubMed1977

Enhanced induction of immune resistance by concanavalin A-bound L1210 vaccine and an immunopotentiator prepared from Coriolus versicolor.

Combined administration of a vaccine consisting of a small number (2 X 10(6)) of L1210 murine leukemic cells treated with glutaraldehyde and concanavalin A and a protein-bound polysaccharide preparation of Coriolus versicolor induced synergistic resistance to L1210 leukemia in BALB/c X DBA/2CrF1 mice. This effect was dependent on the dose and timing of the administration of the protein-bound polysaccharide preparation, being most effective at the time of or 1 day after the second vaccination. Induced resistance was not cross-reactive with P388 murine leukemia, indicating specificity of resistance. This immunopotentiation by the protein-bound polysaccharide did not occur when L1210 cells treated with glutaraldehyde, but not with concanavalin A, were used as a vaccine.

Animals↗
PubMed1976

Interaction of dopamine, methyldopa and reserpine in the sympatho-adrenal system in essential hypertension.

1. The interactions of dopamine, reserpine and methyldopa on blood pressure of normal subjects and of those with essential hypertension were examined. 2. When biosynthesis of noradrenaline from dopamine was blocked by reserpine, dopamine induced a prominent depressor effect in essential hypertension. 3. The long-term treatment with methyldopa induced a marked potentiateion of the pressor action of domapine in hypertension, although no significant pressor response was found in normal subjects. 4. It is suggested that methylnoradrenaline may accumulate in peripheral nerve endings of patients with essential hypertension in comparison with normal subjects, and this accumulated methylnoradrenaline potentiates the pressor response to dopamine in essential hypertension.

Adult↗
PubMed1976

Antitumor activities of newly synthesized N4-acyl-1-beta-D-arabinofuranosylcytosine.

New derivatives of 1-beta-D-arabinofuranosylcytosine were synthesized and their antitumor activities were tested against mouse leukemia L1210. Among the 50 compounds investigated, a series of N4-acyl derivatives with long-chain saturated fatty acids were found to be highly active. The most active derivatives were N4-stearoly-1-beta-D-arabinofuranosylcytosine, which was administered in the form of suspension, and N4-behenoyl-1-beta-D-arabinofuranosylcytosine given in the form of solution. They were superior to the parent compound, 1-beta-D-arabinofuranosylcytosine, in that smaller dosages exhibited strong activities regardless of the treatment schedule, and they were also resistant to cytidine deaminase.

Acylation↗
PubMed1975

Prediction of response to chlorpromazine treatment in schizophrenics.

A dose of 50 mg of chlorpromazine (CPZ) was given to 6 untreated schizophrenic patients and 8 healthy volunteers at 7:00 a.m. before breakfast. Blood samples were taken 3, 6, 9 and 24 hrs after for the analyses of CPZ and its metabolites by gas chromatographic techniques. In the cases of schizophrenic patients, the CPZ treatment was continued. Serum drug levels were monitored and clinical response assessed. The drug levels in serum of another group of patients already under long term treatment were also determined. Although wide inter-patients variations in serum drug levels after a single dose administration were observed, the CPZ level in the patients decreased faster than in the normal subjects. Patients showing high levels of the metabolites such as demethylated CPZ and CPZ sulfoxide after a single dose of CPZ tended to achieve poorer clinical improvement in CPZ therapy, agreeing with the results that poor responders to long term CPZ treatment revealed relatively high levels of the metabolites of CPZ compared with CPZ level. The results indicate that the study of a single dose administration prior to initiating treatment with CPZ can be used to determine how an individual patient would respond to CPZ therapy and be a valuable tool in the rational pharmacotherapy of schizophrenic patients.

Administration, Oral↗
PubMed1975

Sensitivity of DBLA-6 leukemia of rats to known antitumor agents in relation to their clinical effects.

Of 4 lines of myelogenous rat leukemias induced by N-nitrosobutylurea (NBU), DBLA-6 was selected as a screening model for antileukemic agents because of the following characteristics: a) High transplantability either by intravenous (i.v.) or intraperitoneal (i.p.) inoculation; b) linear relationship between inoculum size and survival time; c) marked increase of leucocyte counts in the peripheral blood as the tumor progresses after intravenous inoculation. To investigate reliability in its predicting clinical efficacy, its sensitivity to known antileukemics was studied. To determine the effects, a change of leucocyte counts in the peripheral blood together with the prolongation of life span was checked in the following systems; i.v.-i.v. (i.v.-inoculation, i.v.-injection), i.v.-i.p., i.p.-i.p., i.p.-i.v. Fifty percent cure was obtained with Vincristine, Vinblastine, Daunorubicin, 6-Mercaptopurine, and alkylating agent 838D or 864T. The success of treatment was measured by decrease of leucocytes. Methotrexate, cytosine arabinoside (Ara-C), and cyclophosphamide showed only poor effects, and Mitomycin C, L-asparaginase, and Bleomycin were ineffective. In addition, the chemotherapeutic effects of Vincristine and 864 on this leukemia were quite dependend both on the route of drug injection and on the site of tumor inoculation. Subsequently, our studies are being extended to cover the correlation between drug distribution and tumor localization or dissemination.

Alkylating Agents↗