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Biomedical subjects

R Stern

Publications and source records attributed to R Stern.

At least 289 records · Page 16Linked to original sources
PubMed1969

Induction of interferon by preparations of synthetic single-stranded RNA.

A study was undertaken to help determine whether synthetic nonbase-paired, single-stranded RNA as well as synthetic base-paired, double-stranded RNA could induce interferon. Synthetic polyriboinosinic acid and polyribocytidylic acid induced interferon and interferon-like resistance in several different cell culture systems. However, in the intact rabbit only the most active preparations of single-stranded RNA induced circulating interferon when injected intravenously. The induced interferon and antiviral effect in tissue culture and animals was shown to have characteristics of the interferon system. Contamination of the single-stranded synthetic RNA materials by small amounts of base-paired, double-stranded RNA was ruled out by failure to find sufficient heterologous nucleic acid bases by differential activities of single-stranded and double-stranded RNA's in different cell systems and by failure to detect double-stranded RNA in poly-rI upon chromatography on benzoylated DEAE-cellulose.

Animals↗
PubMed1969

Chromatography of arbovirus ribonucleic acid forms on columns of benzoylated-diethylaminoethyl cellulose.

Benzoylated-diethylaminoethyl cellulose (BD-cellulose) column chromatography was found to be useful in resolving most of the ribonucleic acid (RNA) forms from the replicative cycle of group A arbovirus Semliki Forect virus (SFV). The elution patterns were independent of molecular weight and appeared to be related to the degree of secondary structure in the molecule. Fractions of RNA were taken from a sucrose density gradient of cytoplasmic extracts of SFV-infected chick cells pretreated with actinomycin D. In a linear salt gradient, 16S material cochromatographed with the rapidly eluted ribonuclease resistant core of the double-stranded SFV-RNA and with the homopolymer duplex polyinosinic acid: polycytidylic acid. This fraction, therefore, probably contains an SFV-RNA form similar to the completely double stranded replicative form (RF) of several RNA viruses and bacteriophages. Faster moving (>20S) sucrose gradient fractions eluted more slowly, suggesting a decreasing proportion of secondary structure with increasing sedimentation value. The fractions, therefore, seemed to contain replicative intermediate (RI) structures. The two single stranded forms of SFV-RNA (42S and 26S) could only be eluted from BD-cellulose in the presence of urea or dimethyl sulfoxide, suggesting the presence of minimal secondary structure. Under these conditions, the single-stranded viral RNA forms could not be resolved. Molecular sieve chromatography of the single-stranded RNA forms, performed by passage through an agarose column, also failed to resolve these forms. The viral RNA forms containing a high degree of secondary structure, probably the RF and the RI, could, therefore, be rapidly separated from each other and from the single-stranded forms.

Animals↗