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Biomedical subjects

J Pitha

Publications and source records attributed to J Pitha.

At least 145 records · Page 8Linked to original sources
PubMed1975

Hydrogen bonding abilities of 2,4-dithiouridine derivatives.

The base pairing ability of a di-2,4-thiouridine derivative was studied in carbon tetrachloride solutions by the methods of infrared spectroscopy. The strength of the association by hydrogen bonding was found to decrease in the following order: adenine-uracil, adenine-di-2,4-thiouracil, uracil-uracil, and di-2,4-thiouracil-di-2,4-thiouracil. These findings contrast with the previously demonstrated fact that poly(s2s4U) is strongly self-associated and does not form a complex with poly(A). To correlate these results, it is proposed that long range stabilizing forces are acting between the di-2,4-thiouracil residues in polynucleotide chains. This assumption also explains the existence of an ordered structure in the alternating copolymer poly(s2s4U-A).

Adenine Nucleotides↗
PubMed1973

Inhibition of murine leukemia virus replication by poly(vinyluracil) and poly(vinyladenine).

Poly(1-vinyluracil) and poly(9-vinyladenine), as well as the corresponding polynucleotides poly(uridylate) and poly(adenylate), inhibit acute murine leukemia virus infection in mouse-embryo cells, but they do not significantly inhibit the replication of Sindbis and vesicular stomatitis viruses. The polymers were most effective as inhibitors when added during an early stage of virus replication. Effects of vinyl polymers on the RNA-dependent DNA polymerase from the virions of murine leukemia virus were also observed.

Adenine Nucleotides↗
PubMed1971

Antiviral resistance by the polyinosinic acid-poly (1-vinylcytosine) complex.

The antiviral activities of analogs of the double-stranded complex of polyinosinic and polycytidylic acids [poly(I).poly(C)], which is a potent interferon inducer, have been studied. Structural changes that modify the polymer backbone substantially, such as loops or 2' --> 5' phosphodiester bonds, lead to decreased antiviral activity. Unexpectedly, however, the complex of polyinosinic acid and poly(1-vinylcytosine), which is only a much more distantly related analog of poly(I) . poly(C), shows high activity. It is postulated that the high activity is related to the reduction of the charge/mass ratio and to the existence of this complex in an aggregated state; these are two factors that generally enhance the uptake of compo unds by cells.

Antiviral Agents↗