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In this study, the ability to tailor the peptide-binding specificity of an RNA was investigated. First, variants of the Rev-response element (RRE) RNA with different specificities toward the natural binding partner, Rev, and two RRE-binding aptamers, the RSG-1.2 and the Kl peptides, were identified. Next, hybrid RRE mutants with combinations of two sets of specificity-altering substitutions were tested for peptide-binding specificity. It was shown that in most cases the results of the combination of individual mutations were of an additive nature, therefore providing a way to manipulate the peptide-binding specificity of an RNA in a predictable manner. [ABSTRACT FROM AUTHOR]

The effects of bicarbonate and its combination with the chelating agents, deferiprone (L1), 4,6-dimethyl-1-hydroxypyrimidin-2(1H)-one (AK-4), catechol-3,6-bis(methyleneimino-diacetic-acid) (CBMIDA), and ethane-1-hydroxy-1,1-bisphoshonate (EHBP) in removing depleted uranium (DU) for radiation emergency medicine were examined. After the intramuscular injection of DU in rats, various time schedules of bicarbonate and chelating agent administration were tested. The results indicate that the bicarbonate helps increase significantly the effects of LI and AK-4, while there were no effects of using bicarbonate alone. The effects of bicarbonate on CBMIDA were unclear, and the effects of EHBP were negative. Further studies are necessary to obtain distinctly synergic effects by the combination of chelating agents with bicarbonate. [ABSTRACT FROM AUTHOR]

The effectiveness of deferiprone (L1) in removing depleted uranium (DU) and protecting animals from radiation exposure was examined. Rats that had received 2 mg/kg DU via intramuscular injection were orally administered 100, 200 or 400 mg/kg L1 for 3 days. In all of the groups, significant increases in urinary DU excretion and decreases in DU concentration in the injected muscle were observed, indicating that L1 combined with DU and DU was excreted in the urine. No significant increase in the amount of DU in the excreta or decrease in DU concentration in organs other than the muscles was found. As a preliminary test, the effectiveness of L1 in reducing radiation damage was examined in mice injected with 400 mg/kg L1 and rats administered orally with 200 and 400 mg/kg L1 before and just after x-ray exposure. The results were inconclusive. [ABSTRACT FROM AUTHOR]

Two kinds of 3-hydroxypyridine-2(1 H )-thiones were synthesized. The visible (VIS) spectroscopic analysis indicated that 3-hydroxy-1-methylpyridine-2(1 H )-thione (4a) and 3-hydroxy-1-(2-hydroxyethyl)pyridine-2(1 H )-thione (4b) formed stable 3:1 Fe(III) complexes. The stability constant of the 4b-Fe(III) complex was estimated from the competitive reaction with EDTA and was found to be 36.7 in logß 3 . Treatment of compound 4b with Ga(acac) 3 in D 2 O:CD 3 OD (9:1) solution afforded 3:1 Ga(III) complex, which was assigned by means of 1 H nuclear magnetic resonance ( 1 H NMR) spectroscopy. Treatment of compound 4b with Pb(NO 3 ) 2 gave 4b-Pb(II) complex. The Pb(II) selectivity over biologically relevant Mg(II) and Ca(II) was remarkably improved by adopting N -hydroxyethyl functionality instead of N -methyl group. [ABSTRACT FROM AUTHOR]

The growth and spreading of fibroblast, L929 cells, on various polymeric films prepared by the Langmuir-Blodgett (LB) and casting methods were investigated. L929 cells, which were cultivated on collagen and synthetic polymeric films prepared by the LB method, adhered and spread much more than those on synthetic films prepared by the casting method. This is explained by the fact that cell growth and cell spreading are suitable for L929 cells on the films having serum proteins that contain a high α-helix content, because LB films adsorbed those serum proteins estimated from the circular dichroism measurements of the films immersed in cell culture medium. An exponential relationship was observed from the plot of the cell density vs root mean square of roughness of the films, which is estimated by atomic force microscopy, whereas a linear relationship was observed from the plot of the spreading ratio vs the root mean square of roughness. It is suggested that the correlation between the cell growth or spreading ratio and surface roughness of the films where L929 cells were cultivated is considered to be more important than the correlation between the cell growth or spreading ratio and the contact angle of the films. [ABSTRACT FROM AUTHOR]