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T Ueda

Publications and source records attributed to T Ueda.

At least 1,279 records · Page 71Linked to original sources
PubMed1986

Cholinergic receptor-mediated phosphorylation and activation of tyrosine hydroxylase in cultured bovine adrenal chromaffin cells.

We have identified a 56-kilodalton protein in cultured bovine adrenal chromaffin cells that is phosphorylated when catecholamine secretion is stimulated. Immunodetection on Western blots from both one- and two-dimensional polyacrylamide gels indicated that this protein was tyrosine hydroxylase, the rate-limiting enzyme in catecholamine biosynthesis. Two-dimensional polyacrylamide gel electrophoresis of proteins from unstimulated cells revealed small amounts of phosphorylated protein with a molecular weight of 56K and pI values of 6.37 and 6.27 which were subunits of tyrosine hydroxylase. Nicotinic stimulation of chromaffin cells caused the phosphorylation of three proteins of 56 kilodaltons with pI values of approximately 6.37, 6.27, and 6.15 which were tyrosine hydroxylase. The immunochemical analysis also revealed that there was unphosphorylated tyrosine hydroxylase 56 kilodaltons with a pI of 6.5 which may have decreased on nicotinic stimulation. The phosphorylation of tyrosine hydroxylase was associated with an increase in in situ conversion of [3H]tyrosine to [3H]dihydroxyphenylalanine ([3H]DOPA). Muscarinic stimulation also caused phosphorylation of tyrosine hydroxylase, but to a smaller extent than did nicotinic stimulation. The secretagogues, elevated K+ and Ba2+, stimulated phosphorylation of tyrosine hydroxylase and [3H]DOPA production. The effects of nicotinic stimulation and elevated K+ on tyrosine hydroxylase phosphorylation and [3H]DOPA production were Ca2+-dependent. Nicotinic agonists also raised cyclic AMP levels in chromaffin cells after 2 min. Dibutyryl cyclic AMP and forskolin, which have little effect on catecholamine secretion, also caused phosphorylation of tyrosine hydroxylase. These stimulators of cyclic AMP-dependent processes caused the appearance of two phosphorylated subunits of tyrosine hydroxylase with pI values of 6.37 and 6.27. There was also a small amount of phosphorylated subunit with a pI of 6.15. Both agents stimulated [3H]DOPA production. The experiments indicate that tyrosine hydroxylase is phosphorylated and activated when chromaffin cells are stimulated to secrete. The data suggest that the earliest phosphorylation of tyrosine hydroxylase induced by a nicotinic agonist occurs through stimulation of a Ca2+-dependent protein kinase. After 2 min phosphorylation by a cyclic AMP-dependent protein kinase may also occur. Phosphorylation of tyrosine hydroxylase is associated with an increase in in situ tyrosine hydroxylase activity.

Adrenal Medulla↗
PubMed1986

Inhibition of replication and cytopathic effect of human T cell lymphotropic virus type III/lymphadenopathy-associated virus by 3'-azido-3'-deoxythymidine in vitro.

Human T cell lymphotropic virus type III (HTLV-III)/lymphadenopathy-associated virus is the etiologic agent of the acquired immune deficiency syndrome (AIDS) and AIDS-related complex. The effect of 3'-azido-3'-deoxythymidine (AZT) on the HTLV-III/lymphadenopathy-associated virus infection was quantitatively studied with HTLV type I-carrying MT-4 cells. The AZT compound inhibited HTLV-III-induced cytopathic effect and virus-specific antigen expression in MT-4 cells at concentrations of 5 and 10 microM. In addition, a plaque-forming assay was performed to assess the effect of AZT on virus replication in MT-4 cells freshly infected with HTLV-III and in continuous HTLV-III-producing Molt-4/HTLV-III cells. Results showed that AZT efficiently and effectively inhibited the replication of HTLV-III in infected MT-4 cells. AZT is a strong inhibitor of reverse transcriptase activity of HTLV-III as a triphosphate, to such a degree that even 1.0 pM azido-TTP inhibits 50% of reverse transcriptase activity. However, it did not show any effect in the HTLV-III-producing cell line Molt-4/HTLV-III. Thus, AZT has no effect on virus replication of an already integrated virus. When 5 microM AZT was added to HTLV-III-infected MT-4 within 20 h after infection, a striking suppressive effect was noticed. This concentration was much lower than that which inhibits the growth of MT-4 cells. These results confirm those found in a previous report (H. Mitsuya, K. J. Weinhold, P. S. Furman, H. S. Clair, S. N. Lehrman, R. C. Gallo, D. Bolognesi, D. W. Barry, and S. Broder, Proc. Natl. Acad. Sci. USA 82:7096-7100, 1985) and suggest that AZT might be used as an experimental antiviral agent for AIDS and AIDS-related complex.

Antigens, Viral↗
PubMed1986

Inhibition of monoamine oxidase A-form and semicarbazide-sensitive amine oxidase by selective and reversible monoamine oxidase-A inhibitors, amiflamine and FLA 788(+).

In vitro studies demonstrated that two selective monoamine oxidase (MAO)-A inhibitors, amiflamine and FLA 788(+), have been shown to inhibit semicarbazide-sensitive amine oxidase (SSAO) in rat testis and lung homogenates in a concentration-dependent way. The inhibition was not greatly influenced by pretreatment of the preparations with either clorgyline (10(-3) mol/l), l-deprenyl (10(-3) mol/l) or SKF 525A (10(-4) mol/l). The two compounds showed a time-dependent inhibition of SSAO, and for the initial phase of the inhibition, amiflamine is a competitive inhibitor with a Kislope of 135 mumol/l, but FLA 788(+) is a noncompetitive inhibitor with a Ki value of 180 mumol/l. After preincubation for 60 min at 37 degrees C, however, inhibition by amiflamine was found to be essentially irreversible whereas that produced by FLA 788(+) was still noncompetitive and reversible. These two compounds also reversibly and competitively inhibited rat testis MAO-A with FLA 788(+) being much more selective towards this MAO (Kislope = 0.26 mumol/l for FLA 788(+) and 7 mumol/l for amiflamine, respectively). The present results indicate that both MAO-A-selective inhibitors also inhibit SSAO in vitro, but their properties as SSAO inhibitors differ from those as MAO-A inhibitors.

Animals↗
PubMed1986

Differential count of 5,000 leukocytes for acute nonlymphocytic leukemia patients during remission.

In order to find the level of leukemic cells during remission a differential count of 5,000 leukocytes was made in 91 acute nonlymphocytic leukemia cases during their first complete remission. Patients were divided into three groups according to the level of leukemic cells, i.e., 0-1/5,000, 2-4/5,000 and 5-/5,000. A close correlation was observed between the survival of patients and the level of leukemic cells and their tendency to decrease or increase during remission. All patients in whom leukemic cells rose from 0-1/5,000 to a level higher than 8/5,000 suffered a documented relapse after 4-8 weeks. This method appears to be a good supportive examination for acute leukemia patients during remission.

Acute Disease↗
PubMed1986

Antitumor activity of derivatives of neplanocin A in vivo and in vitro.

Neplanocin A is a cyclopentenyl analog of adenosine which has been isolated from the culture filtrate of Ampullariella reqularis. Antitumor activity of twenty three derivatives of neplanocin A was examined against L1210, sarcoma 180 and L5178Y. Neplanocin A showed a marked inhibition of growth of L1210 in vivo. Other derivatives which had a 2' or 3'-substituted cyclopentene group showed weak cytotoxicity against L5178Y cells in vitro. Neplanocin A inhibited the biosynthesis of ribonucleic acid (RNA) and protein, while 6-chloroneplanocin A, a new active derivative, showed a specific inhibition of only RNA synthesis. The two hydroxy groups in the cyclopentene moiety with a ribose type structure are important for marked antitumor activity.

Adenosine↗
PubMed1986

Studies of monoamine oxidase and semicarbazide-sensitive amine oxidase. I. Inhibition by a selective monoamine oxidase-B inhibitor, MD 780236.

In vitro studies of the effect of MD 780236, a selective monoamine oxidase (MAO)-B inhibitor, on a semicarbazide-sensitive amine oxidase (SSAO) in rat testis and lung showed that this compound dose-dependently inhibited SSAO activity. The extents of inhibition of MAO-A, -B and SSAO in these two rat tissues by this compound after 30 min of preincubation were found to be MAO-B greater than MAO-A greater than SSAO. This selectivity was also evident in preparations without preincubation. Degree of inhibition of SSAO was not significantly influenced by pretreatment with either 10(-3) M clorgyline, I-deprenyl or 10(-4) M SKF 525A. Inhibition of SSAO was not enhanced by varying the time of preincubation of the enzyme and the compound, indicating direct action on and reversible inhibition of SSAO. The inhibition of SSAO by MD 780236 was non-competitive with or without preincubation, with a K1 value of 110 muM. Although MD 780236 is a selective and "suicide substrate" inhibitor of MAO-B, these present results indicate that this compound may also inhibit SSAO activity, but by a mechanism different from that for MAO-B. These findings confirm an earlier hypothesis that compounds that inhibit both MAO and SSAO have totally different modes of action on these two different amine oxidases.

Animals↗
PubMed1986

[Circadian rhythm of air-borne bacteria and dust particles in a mouse breeding room].

The circadian rhythm of air-borne bacteria and dust particles in a mice breeding room was studied at 1-hour intervals on the first, third and fifth day after accommodation of the animals. The numbers of air-borne bacteria in the room increased day by day after accommodation, and showed a circadian rhythm which went down at about noon and rose with three peaks at about 20:00, 1:00 and 8:00. The numbers of dust particles tended to decrease from day to day, and they showed almost the same circadian rhythm as the air-borne bacteria. Correlations between air-borne bacteria and dust particles were not significant for each particle level on the first day, but were significant for all the particle levels of 0.3, 1, 2, and 5 microns at the third day, and were also significant at particles levels of 0.5 micron or more on the fifth day.

Air Microbiology↗
PubMed1986

[Effects of environmental temperature on thymus and spleen weights and lymphocytes in mice].

Thymus and spleen weights and lymphocytes in the blood were examined in mice transferred from 22 degrees C to 12 degrees C or 32 degrees C environments. After the exposure to either environment, organ weights tended to decrease. In mice exposed to 12 degrees C, the number of WBCs and mononuclear cells and the ratio and the number of T cells decreased on day 1 and/or 3 after the exposure. The number of B cells also declined on day 3, but the ratio of B cells increased on days 3 and 7. In mice exposed to 32 degrees C, the number of WBCs and mononuclear cells and the number of T cells decreased on day 1 and increased on day 7 and/or 14. The ratio of T cells declined on days 1, 3 and 7, while that of B cells increased on day 3, and the number of B cells increased on day 7. These results show that wide variations in environmental temperature affect the weights of organs and the number of cells which act on immune responses in mice.

Animals↗
PubMed1986

[New additional operation in the prevention of gastric stasis after selective gastric vagotomy with antrectomy].

The new additional operation for the prevention of the gastric stasis after the selective gastric vagotomy with antrectomy (SV + A) was performed. Our additional operative procedure was followed: After selective gastric vagotomy and antrectomy, gastroduodenostomy was anastomosed at acute angle with the longitudinalis of the stomach. Then, both lesser and greater omentum were incised outside of the gastric vessels. After these procedure, posterior wall sided to lesser curvature was fixed with the edge of the hepatogastric ligament and posterior wall sided to greater curvature was fixed with the retroperitoneum inferior to the pancreas by several sutures. The outcome of these treatments of the additional operation on SV + A enabled to shorten the duration of drainage of gastric juice, as well as smooth intake. By fluoroscopic examination one month after operation, gastric stasis was observed on SV + A due to the contrast medium stored in the ptotic corpus, whereas, in the case of SV + A with our additional operation, smooth gastric emptying was observed without any stasis of the contrast medium, because the corpus was placed upper from the anastomosis portion. In conclusion, our additional operation to SV + A was able to perform easy and safely, and was observed the effective prevention of gastric stasis.

Duodenal Ulcer↗
PubMed1986

Inhibitory action of 10-deazaaminopterins and their polyglutamates on human thymidylate synthase.

The action of 10-deazaaminopterin, its 10-alkyl derivatives, and their polyglutamates against thymidylate synthase (TMPS) from human acute myeloblastic leukemia was examined. Comparison of aminopterin with methotrexate showed that the methylation of the N10-position (methotrexate) increased the inhibitory effect of aminopterin on TMPS. In contrast, alkylation of the 10-position of 10-deazaaminopterin decreased inhibition of TMPS, and the 50% inhibitory concentration values were progressively higher, in the order 10,10-dimethyl-, 10-methyl-, and 10-ethyl-derivatives. The addition of gamma-glutamyl moieties to both 10-deazaaminopterin, and one of its alkylated analogs, 10-ethyl-10-deazaaminopterin, enhanced inhibition. The maximum inhibition was achieved with the addition of three glutamyl moieties to 10-deazaaminopterin and two glutamyl moieties to 10-ethyl-10-deazaaminopterin, respectively. Thus, 10-deazaaminopterin-tetraglutamate was 138-fold and 10-ethyl-10-deazaaminopterin-triglutamate was greater than 51-fold more active than their respective parental compound. The compounds 10-deazaaminopterin and its polyglutamates, 10-methyl- and 10,10-dimethyl-analogs, inhibited TMPS in a noncompetitive fashion with respect to 5,10-methylene-tetrahydropteroylglutamate. Ki values for the monoglutamates were 220 microM, 310 microM, and 225 microM, respectively. In contrast, 10-ethyl-10-deazaaminopterin and its polyglutamates inhibited TMPS in a competitive fashion with a Ki value of 410 microM for the monoglutamate. With 5,10-methylene-tetrahydropteroylpentaglutamate as a substrate, 10-deazaaminopterin and its polyglutamates behaved as mixed type inhibitors, and 10-ethyl-10-deazaaminopterin, monoglutamate and diglutamate, behaved as noncompetitive inhibitors, whereas its pentaglutamate behaved as a mixed-type inhibitor. These results suggest that the addition of gamma-glutamyl moieties to the substrate also caused the change in the mode of inhibitory action of these compounds. These findings also show that both replacement of the N10-position of the 4-aminopteroyl structure with a methylene group and its alkylation caused interesting and unexpected changes in the structure-activity relationships and the mode of action for these 4-aminopteroyl antifolates as inhibitors of TMPS, which may be therapeutically relevant.

Alkylation↗
PubMed1986

Pharmacokinetics of aclarubicin and its metabolites in humans and their disposition in blood cells.

The pharmacokinetics of aclarubicin, a new anthracycline antibiotic, was studied in five patients with acute leukemia or in L1210 cell suspension. Aclarubicin disappeared very rapidly from plasma and whole blood after administration at a dose of 20 mg per patient by iv bolus injection. The concentration of active metabolite M1, on the other hand, increased for up to 2 or 4 hrs after administration and exceeded that of aclarubicin, and then remained at much higher concentrations than aclarubicin for up to 24 hrs after administration. In addition, the levels of aclarubicin and its metabolites in whole blood were much higher than the corresponding plasma levels in four of the patients. The drug concentrations in blood cells of 11 patients determined 4 hrs after administration showed a significant positive correlation with leukocyte counts. Moreover, the concentration of aclarubicin and its metabolites was found to be much higher in the leukocyte fraction than in the erythrocyte fraction in vivo and in vitro. These findings indicate that aclarubicin and its metabolites in blood cells were mainly accumulated in leukocytes. In the study of intracellular drug distribution in L1210 cells, the largest amount of aclarubicin was incorporated into the nuclear fraction. This suggests a close relationship between the pronounced drug accumulation in leukocytes and the high affinity of aclarubicin for DNA.

Aclarubicin↗