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Biomedical subjects

L D Hodge

Publications and source records attributed to L D Hodge.

26 records · Page 2Linked to original sources
PubMed1972

Adenovirus messenger RNA in mammalian cells: failure of polyribosome association in the absence of nuclear cleavage.

The nuclear synthesis of adenovirus-specific RNA late in the infectious cycle in the presence of toyocamycin (an adenosine analogue) has been investigated. There is reduced synthesis of viral RNA with an accumulation of virus-specific RNA in the molecular weight range of at least 4 to 8 x 10(6). No new viral RNA associates with cytoplasmic polyribosomes. In addition, hybridization competition experiments indicate a 70% competition between these large nuclear transcripts and polyribosome-associated viral RNA that was synthesized in the absence of inhibitor. These data are consistent with the following interpretations: complete nuclear processing of viral RNA is necessary for polyribosome association, and precursor viral message(s) contain sequences that are lost normally during post-transcriptional processing.

Adenoviridae↗
PubMed1969

Nonpermissive infections of mammalian cells: synthesis of inluenza virus genome in HeLa cells.

The RNA synthesis of a single-stranded, multisegmented viral genome has been investigated in nonpermissive host cells. In HeLa cells, both single- and double-stranded influenza viral RNA were made and accumulated, and synthesis was completed by 15 hours. The evidence indicated that all pieces of the genome were synthesized. At least as much viral RNA was synthesized in HeLa cells as in permissive chick embryo fibroblasts cells. Explanations for this nonpermissive infection based on reduced synthesis of viral RNA or rapid destruction of newly synthesized RNA, uncontrolled synthesis of RNA, or partial synthesis of the genome appear to have been ruled out by this investigation. The persistently high amounts of double-stranded RNA, combined with the reported lack of dispersion of nucleocapsid protein from the nuclear region of the HeLa cell are consistent with a failure of assembly of the virion in this host. This nonpermissive infection of HeLa cells with influenza virus may offer a unique system for the accumulation of the intermediates involved in the assembly of a complex RNA viral genome.

Animals↗
PubMed1969

Persistence of messenger RNA through mitosis in HeLa cells.

The decrease in protein synthesis which occurs in mammalian cells during cell division is associated with significant disaggregation of polyribosomes. For determining whether messenger RNA survives this disaggregation, the reformation of polyribosomes was investigated in synchronized HeLa cells as they progressed from metaphase into interphase in the presence of 2 microg/ml Actinomycin D. The persistence of messenger during cell division was evidenced by: (1) a progressive increase in the rate of protein synthesis in both treated and untreated cells for 45 min after metaphase; (2) reformation of polyribosomes, as determined by both sucrose gradients and electron microscopy, within 30 min after the addition of Actinomycin D to metaphase cells; (3) the persistence of approximately 50% of the rapidly labeled nonribosomal RNA which had associated with polyribosomes just before metaphase; (4) the resumption of synthesis, following cell division, of 6 selected peptides in Actinomycin-treated cells.

Centrifugation, Density Gradient↗