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1.
Influence of Hydrocortisone on Chick Embryo Retina Development 总被引:1,自引:1,他引:0
Renza Vento Giuseppina D'Ancona Michela Giuliano Gennaro Taibi Giovanni Tesoriere 《Journal of neurochemistry》1987,48(6):1693-1698
Treatment of chick embryos in ovo with hydrocortisone-21-phosphate (a single dose of 150 micrograms) caused a marked reduction of retinal thymidine kinase activity 24 h later. The inhibitory effect was highest (65-70%) in 8-10-day-old embryos and declined with age, disappearing after day 15. It was accompanied by a reduction in thickness of the retinal layers. Adrenocorticotropic hormone (ACTH) treatment (10 micrograms daily for 2 days) also produced an age-dependent inhibitory effect on retinal thymidine kinase, whereas treatment with a single dose of 200 micrograms of metopirone, a compound that prevents the 11 beta-hydroxylation of steroid molecules in the adrenal glands, impeded the decrease in thymidine kinase activity that normally occurs in chick embryo retina after day 9 of development. In addition, metopirone prevented the inhibition exerted by ACTH on thymidine kinase activity but had no effect on the action of hydrocortisone. 相似文献
2.
This paper studies the influence of uridine on the effects exerted by D-glucosamine in rat C6 glioma cells. 2 mM uridine increased markedly both the cytotoxic effect of the aminosugar and the inhibition of thymidine incorporation into acid-insoluble fraction. Furthermore the complete resumption of the capacity to incorporate either 3H-thymidine or 3H-mannose which was observed after the removal of the aminosugar, was impeded when the cells were treated contemporaneously with D-glucosamine and uridine. An exposure for 4 hr to 20 mM glucosamine alone enhanced about 15-fold the cellular pool of UDP-N-acetylhexosamines; the addition of 2 mM uridine intensified the expansion of this pool, which became about 35-fold the control value. The findings suggest a connection between the accumulation of UDP-N-acetylhexosamines in the cells and the appearance of D-glucosamine cytotoxicity. 相似文献
3.
Biochemical Aspects of Chick Embryo Retina Development: The Effects of Glucocorticoids 总被引:1,自引:1,他引:0
Giovanni Tesoriere Renza Vento Gennaro Taibi Giuseppe Calvaruso Maria Rita Schiavo 《Journal of neurochemistry》1989,52(5):1487-1494
In chick embryo retina during development, DNA synthesis and the activities of DNA polymerase, thymidine kinase, thymidylate synthetase, and ornithine decarboxylase (ODC) declined in parallel from day 7 to 12. The administration in ovo of hydrocortisone reduced significantly, particularly at 8-10 days of incubation, both DNA synthesis and the four enzyme activities tested. The effect was dose dependent, reaching the maximum with 50-100 nmol of hydrocortisone, 8-16 h after treatment. The highest inhibition was found for ODC activity (70%), followed by thymidine kinase activity (62%) and DNA synthesis (45%), whereas activities of DNA polymerase and thymidylate synthetase were reduced only by 30%. The inhibitory effect was exerted by all the glucocorticoids tested, with dexamethasone and hydrocortisone being the most efficacious. The results support the view that glucocorticoids reduce the proliferative events in chick embryo retina, particularly at 8-10 days of embryonic life. 相似文献
4.
5.
D Di Berardino M Ronne I Burguete M B Lioi L Taibi D Matassino 《The Journal of heredity》1987,78(4):225-230
R-banded prometaphase karyotypes of the goat are presented using both fluorescent and light staining techniques. A model for the standardization of the R-banded prometaphase goat karyotype is suggested. 相似文献
6.
Hadda TB Akkurt M Baba MF Daoudi M Bennani B Kerbal A Chohan ZH 《Journal of enzyme inhibition and medicinal chemistry》2009,24(2):457-463
A series of nine polypyridyl-ruthenium (II) complexes (N-ligands = 2,2'-bipyridines; 2,2'-6',2'-terpyridines, di-alkyloxy-2,2'-6,2-bipyridine-3,3'-di-carboxylates), were tested against Mycobacterium tuberculosis (MBT). The complex (11) showed remarkable activity against MBT as compared to other complexes, (1-10). The aquo ligand of complex (11), as opposed to other chloro and acetonitrile derivatives, appears to play a key role in the antitubercular potency of this new class of metal-based compounds. 相似文献
7.
G Tesoriere R Vento G Calvaruso G Taibi M C Gueli 《Biochimica et biophysica acta》1981,660(2):348-358
1. A nonspecific nucleoside phosphotransferase (nucleotide : 3'-deoxynucleotide 5'-phosphotransferase, EC 2.7.1.77), purified from chick embryos, catalyzes the transfer of phosphate ester from a nucleotide donor to a nucleoside acceptor. 2. The enzyme exhibits sigmoidal kinetics with respect to nucleoside monophosphate donors, but with respect to nucleoside di- or triphosphate donors and nucleoside acceptors hyperbolic kinetics were obtained. 3. The nucleoside phosphotransferase of chick embryo is unstable to heat and is protected from inactivation by a large number of nucleosides. 4. Nucleoside di- and triphosphates lower both the concentration of nucleoside monophosphates required for half-maximal velocity and the kinetic order of reaction measured with these phosphate donors. On the contrary, nucleoside di- or triphosphate do not modify the kinetic parameters evaluated for nucleoside acceptors. 5. We suggest that the nucleoside phosphotransferase contains both substrate and regulatory sites. It seems that the free apoenzyme is converted, by means of cooperative interactions between regulatory sites, into an enzyme-nucleotide complex, which is particularly stable at 37 degrees C. 相似文献
8.
Regulation of Oleoyl-CoA Synthesis in the Peripheral Nervous System: Demonstration of a Link with Myelin Synthesis 总被引:6,自引:1,他引:5
Bertrand Garbay Françoise Boiron-Sargueil Michael Shy Taibi Chbihi Huiyuan Jiang John Kamholz Claude Cassagne 《Journal of neurochemistry》1998,71(4):1719-1726
Abstract: We studied the regulation of oleic acid synthesis in the PNS. During mouse postnatal development, the proportion of 18:1 rises in the sciatic nerve from 17% at 5 days of age to 33% at 25 days. However, this rise does not occur in the dysmyelinating mutant mouse trembler. In normal mouse development, the total stearoyl-CoA desaturase (SCD) activity measured in sciatic nerve homogenates is high during the first 3 weeks. Yet in trembler nerves, this SCD activity represents only 15% of normal values. Using the RT-PCR technique, we demonstrate that the SCD2 isoform is predominantly expressed in the PNS. Northern blot analysis showed that the mRNA levels for SCD2 parallel those of other specific myelin proteins in both normal mouse and trembler mutant development. Similar experiments in a rat demyelination-remyelination model confirmed that SCD2 mRNA levels are regulated in the PNS in a similar manner to myelin-specific proteins. 相似文献
9.
Mahajan DT Masand VH Patil KN Ben Hadda T Jawarkar RD Thakur SD Rastija V 《Bioorganic & medicinal chemistry letters》2012,22(14):4827-4835
In present work, 53 synthetic prodiginines were selected to establish thriving CoMSIA (Comparative Molecular Similarity Indices Analysis) model to explore the structural features influencing their anti-malarial activity. POM (Petra/Osiris/Molinspiration) was carried out to get insight into requirements that can lead to the improvement of the activity of these molecules. The CoMSIA model, based on a combination of steric, electrostatic and H-bond acceptor/donor effects, is with R(2)(cv)=0.738 and R(2)=0.911. The analyses reveal that lipophilicity, hydrogen donor/acceptor and steric factors play crucial role. The study with constructive propositions could be useful for the design of new analogues with enhanced activity. 相似文献
10.
Eleonora Lalle Licia Bordi Claudia Caglioti Anna Rosa Garbuglia Concetta Castilletti Chiara Taibi Francesca Cristofari Maria Rosaria Capobianchi 《PloS one》2014,9(4)