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Biomedical subjects

S Takeda

Publications and source records attributed to S Takeda.

At least 847 records · Page 47Linked to original sources
PubMed1982

Time-related differences in noradrenaline turnover in rat brain regions by stress.

Male Wistar rats were stressed by immobilization from 15 to 180 min and the effect on noradrenaline (NA) and 3-methoxy-4-hydroxyphenylethyleneglycol sulfate (MHPG-SO4) contents in eight discrete brain regions were determined. NA levels significantly decreased and MHPG-SO4 levels increased in the hypothalamus, amygdala, thalamus, hippocampus, pons+ med.obl. and cerebral cortex. By contrast, the basal ganglia exhibited increases in NA levels and transient decreases in MHPG-SO4 levels. The midbrain failed to show significant alterations. The most rapid and marked increase in MHPG-SO4 level was found in the hypothalamus. When rats were exposed to stress after treatment with probenecid 400 mg/kg, the hypothalamus and amygdala showed greater accumulations of MHPG-SO4 in the early phase of stress, while the pons+ med.obl. and basal ganglia in the later phase. The other regions showed virtually the same accumulations. These results suggest that NA release is enhanced by immobilization in the six regions mentioned above and that response of NA neurons occurs rapidly in the hypothalamus and amygdala but is delayed in other regions.

Adrenal Cortex Hormones↗
PubMed1982

Effect of 1,3,3,5,5-pentaziridino-1-thia-2,4,6-triaza-3,5-diphosphorine-1-oxide, a new antitumor agent with inorganic ring, on various experimental tumors.

1,3,3,5,5-Pentaziridino-1-thia-2,4,6-triaza-3,5-diphosphorine-1-oxide (SOAz), a new antitumor agent, was evaluated for antitumor activity against various mouse- and rat-tumor systems. The optimal treatment regimens of SOAz (i.p.) gave 262% and 134% increase in life span (ILS) in mice with P388 leukemia and L1210 leukemia implanted intraperitoneally, respectively, and 239% ILS in rats with Yoshida sarcoma of which 86% survived for 60 d after intraperitoneal tumor implantation. The compound showed a definite activity against Lewis lung carcinoma implanted intravenously. The compound also exhibited 80-100% inhibition of tumor local growth in all of four experimental tumor systems used in the present study. In contrast to cyclophosphamide, SOAz was active against B16 melanoma and Meth A, and demonstrated high activity against a subline of L1210 leukemia resistant to cyclophosphamide.

Animals↗
PubMed1982

Antitumor activities of harringtonine and homoharringtonine, cephalotaxus alkaloids which are active principles from plant by intraperitoneal and oral administration.

Antitumor activities of harringtonine(HA) and homoharringtonine(HO) both belong to cephalotaxus alkaloids were compared with those of vinca alkaloids, vincristine (VCR) and vinblastine (VLB). HA and HO had significant activities against P388 leukemia, L1210 leukemia and B16 melanoma by intraperitoneal injection comparable to VCR and VLB. The therapeutic index (LD10/ED50) of HA and HO in B16 melanoma system was 1.90 and 2.31, while those of VCR and VLB were 1.38 and less than 1.00, respectively. The oral administration of these cephalotaxus alkaloids evoked a significant antitumor activity but that of vinca alkaloids induced no activity against P388 and B16 melanoma. The efficacy of HO on various tumor systems was equal or greater than that of HA when comparison was made between these two cephalotaxus alkaloids. In contrast to VCR and VLB, HA and HO demonstrated moderate activity against P388/VCR, a subline of P388 resistant to vincristine. The intraperitoneal injection of VCR or VLB produced an increase in the mitotic index of P388 cells as compared with the control values, but HA or HO decreased it. HA and HO, cephalotaxus alkaloids are a new class of active compounds of plant origin which may differ from the vinca alkaloids in the mechanism of antitumor activity.

Administration, Oral↗
PubMed1982

[Aluminous cement for dental application (author's transl)].

The various materials such as zinc oxide eugenol pastes, calcium hydroxide slurry and self hardening polymers have been used for the root canal filling and pulp capping. However, those materials have various problems in terms of biocompatibility and physical properties in clinical use. The development of root canal filling and pulp capping materials has been carried out with powder-liquid system which consisted of aluminous cement added to 20 wt% Ca (OH)2 and polyvinylalcohol solutions. The influence of polyvinylalcohol concentrations and L/P ratio on physical properties and biocompatibility were investigated. The results were as follows: 1. The initial setting time was showed between 3 and 20 minutes according to polyvinylalcohol concentration and L/P ratio and delayed linearly by increasing the L/P ratio. 2. The consistency was indicated between 18 and 51 mm with polyvinylalcohol concentration and L/P ratio. The lower the L/P ratio, the thicker was the consistency. 3. The solubilities in distilled water were 2.7-7.3% and 3.9-8.4%, respectively, after storage for 24 hours and 1 week, while those values in 199 medium were 2.9-6.2% and 4.4-9.9%, respectively, after storage for 24 hours and 1 week. 4. The pH values in distilled water were indicated high alkaline conditions of about 11.5 after storage for 24 hours and was not influenced by the repeated immersions. On the other hand, the pH values in 199 medium were showed high alkaline conditions of about 11.0 after storage for 24 hours, but decreased rapidly to the neutral conditions of about 8.0 with the repeated immersion. 5. The compressive strengths were increased by the use of higher polyvinylalcohol concentration and lower L/P ratio and indicated from 26 kg/cm2 and 278 kg/cm2. 6. By the use of the tissue culture method, mild response with the un-set cement was recognized from the morphological observation. In the case of the set cement, the cell morphological changes showed no significant difference in the cytotoxicity compared with that of control culture. The disappearance of the cytotoxicity was recognized in according to the progress of setting process.

Aluminum↗
PubMed1981

Gene expression of myofibrillar proteins in single muscle fibers of adult chicken: micro two dimensional gel electrophoretic analysis.

Using a micro two dimensional gel electrophoretic system and silver stain method, we examined the isoform patterns of myofibrillar proteins in single muscle fibers of adult chicken. Several isoforms of myosin light chains, tropomyosin, troponin T, troponin I, and troponin C were identified. Analysis of pectoral, anterior latissimus dorsi, sartorius and soleus muscle revealed that single fibers contained either fast or slow form of each of the troponin subunits, indicating that troponin exists as a 'homocomplex.' The form of troponin in a given cell was associated with that of myosin light chains. The form of tropomyosin, however, was not associated with those of myosin light chains and troponin, but was tissue specific. Overall, we found four combinations of isoforms of myosin light chains, troponin subunits and tropomyosin subunits. In adult dystrophic chicken the isoform patterns of tropomyosin and troponin T in single fibers of pectoral muscle markedly deviated from the normal patterns.

Animals↗
PubMed1981

Earlier diagnosis of gastric infiltrating carcinoma (scirrhous cancer).

We approached the early diagnosis of gastric infiltrating carcinoma, scirrhous cancer, by a retrospective study of 19 patients, together with a prospective study of a single patient, by reexamination and follow-up of gastric roentgenographs and endoscopic films. This study suggests that an early feature of this type of gastric cancer might be IIc- or III + IIc-like depression in the body of the stomach, probably in the fundic region of the stomach. A shallow depression or a slight stiffness of the gastric wall may be one of the earliest roentgenographic or endoscopic findings helpful in early detection of this disease.

Adenocarcinoma, Scirrhous↗
PubMed1981

Age-dependent inhibition of growth of mouse neuroblastoma cells by mouse brain extract.

In the developing mouse brain, inhibition of cell proliferation and cell death occur naturally. In order to study the factors which control growth and differentiation of neural cells, we added brain extract of mice of various ages to N-18 mouse neuroblastoma cell cultures. Brain extract from newborn mice inhibited N-18 cell growth and, at high concentrations, induced cell death. The colony-forming ability of N-18 cells was also inhibited by brain extract. This inhibitory effect of brain extract on the colony-forming ability increased with fetal age and became most significant at birth, then gradually decreased. Brain extract of 19-day embryos promoted the neurite outgrowth of N-18 cells at low concentrations, at which cell growth was not affected. On the other hand, brain extract of adult mice had no effect on the growth and morphology of cells at the same concentration.

Aging↗
PubMed1981

Pharmacological studies on iridoid compounds. III. The choleretic mechanism of iridoid compounds.

We made a study on choleretic property and mechanism of action of iridoid compounds as well as dehydrocholate (DHC), cholate (CA), and salicylate (SA), examining their effects on factors such as bile flow, bile acids, electrolytes (Na+, K+, Cl-, and HCO3-), and their metabolites. Each sample showed a characteristic property, respectively. Genipin and patrinoside decreased biliary concentrations of bile acids, Na+, Cl-, and HCO3-, corresponding to their rapid choleretic actions which were due to bile acids independent fraction. The choleretic action of DHC is approximately twice as potent as that of CA. Their actions were due to bile acids-dependent fraction. CA gave a marked increase in Na+ concentration but DHC did not. And both compounds gave a marked diminution in Cl- concentration and weakly decreased HCO3- concentration. SA showed a weak and durable choleretic action and also gave a marked increase in HCO3- concentration. The main metabolite detected from the bile given genipin was genipin-1-O-glucuronic acid (GGA). The periodical pattern of GGA level in bile was in agreement with that of genipin- induced choleretic action, and quantitatively cation, anion gap produced was nearly compensated by biliary concentration of GGA. From out various results, the choleretic mechanism of iridoid compounds is considered to be as follows: The hemiacetal moiety of them undergoes conjugation in the liver to give glucuronide. Glucuronide thus formed is secreted into the biliary tree being coupled mainly with Na+ and water is passively excreted.

Animals↗
PubMed1981

The choleretic mechanism of coumarin compounds and phenolic compounds.

In this work, the choleretic properties and mechanism of coumarin compounds and phenolic compounds were studied by examining their effects on parameters such as bile flow, bile acids, electrolytes, and biliary metabolites. Choleretic intensity and property of each sample was far different. The choleretic efficacy of 6, 7-dimethylesculetin (6,7-DME) was far weaker than that of 4 methylumbelliferone (4-MU). 4-hydroxybenzyl alcohol (4-HBA), isoeugenol, vanillin, paeonol, and phenolphthalein accelerated bile secretion, but 4 (B-D-glucopyranosyloxy)-benzyl alcohol, safrol, and arbutin did not. 4-MU and 4-HBA underwent conjugation in the liver to give mainly a glucuronide and their metabolites were rapidly excreted into bile, but 6, 7-DME was converted into some metabolites which were excreted little by little over a long period of time. The biliary gap between cations (NA+, K+) and anions (CL-, HCO3-, bile acids) produced after intravenous administration of 4-MU, 6, 7-DME, and 4-HBA was substantially offset by biliary concentrations of their metabolites. It was suggested that a hydroxyl group which can be mainly converted into a glucuronide is necessary in exerting a strong choleretic action. The choleretic mechanism of coumarin compounds and phenolic compounds is considered to be as follows: Their metabolites (mainly glucuronide) are actively secreted into the biliary tree as an organic anion coupled with Na+ or K+, and water is passively excreted.

Animals↗