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Biomedical subjects

A Adams

Publications and source records attributed to A Adams.

At least 199 records · Page 11Linked to original sources
PubMed1975

Spontaneous interferon production and Epstein-barr virus antigen expression in two human lymphoid cell lines and their somatic cell hybrids.

Two human lymphoid cell lines, Raji and Namalwa, and seven somatic cell hybrids between these two cells were tested for spontaneous interferon production. Namalwa and three of the hybrids produce interferon while the four other hybrids, like Raji, do not. Though the Namalwa line is relatively resistant to superinfection with the Epstein-Barr virus (EBV), all hybrids are as susceptible to EBV as the Raji parent. High extracellular concentrations of interferon likewise had little effect on EBV superinfection of Raji or the hybrid cells and it is possible that Raji produces some factor that antagonizes the action of interferon to allow virus expression.

Antigens, Viral↗
PubMed1973

Linear association between cellular DNA and Epstein-Barr virus DNA in a human lymphoblastoid cell line.

High-molecular-weight DNA from cell line Raji (derived from Burkitt's lymphoma), which contains 50-60 copies of Epstein-Barr virus DNA per cell, was fractionated in neutral solution by several cycles of CsCl gradient centrifugation in fixed-angle rotors. Under the fractionation conditions used, intact Epstein-Barr virus DNA from virus particles can be separated from the less-dense cellular DNA. In contrast, a large proportion of the intrinsic Epstein-Barr virus DNA component of Raji cells remains associated with cellular DNA, as determined by nucleic acid hybridization. This interaction, which is resistant to Pronase and phenol treatment, is not the result of aggregation. When the molecular weight of Raji DNA is reduced by hydrodynamic shear, the amount of virus DNA associated with cell DNA decreases. However, some virus DNA still remains bound to fragments of cellular DNA after shearing. The association is completely destroyed in alkaline solution. Molecular weight analysis of Raji DNA after denaturation showed that the alkali-induced release of Epstein-Barr virus DNA was specific and not the result of random single-strand breaks. These data indicate that Epstein-Barr virus DNA is linearly integrated into Raji cell DNA by alkali-labile bonds.

Burkitt Lymphoma↗
PubMed1973

Transposition of the arsenate resistance locus of Bacillus subtilis strains 23 and 168.

Wild-type Bacillus subtilis strains 23 and 168 are resistant to high concentrations of sodium arsenate. The genetic configurations of the arsenate resistance loci of these two related strains of B. subtilis have been characterized. The transformable 168 strain has a single resistance locus which maps between phe and aroD in the terminal third of the genome. In contrast, strain 23 is shown to have its single arsenate resistance locus between purB and thr in the first third of the bacterial chromosome. Moreover, in strain 23 the chromosomal segment equivalent to the phe-linked asa region of 168 strains is missing. DNA isolated from 23 strains is able to transform 168 arsenate-sensitive strains to resistance and the heterologous 23 DNA is found to preferentially establish a new purB linked asa locus in such transformed cells. Thus, the majority of phenotypically arsenate-resistant cells recovered after exposure of competent 168 sensitive mutants to 23 DNA are "heterozygous" and still retain their phe-linked mutated asa locus. The tolerance of several of these heterologously transformed hybrid strains to arsenate suggests that the 168 and 23 asa gene products are similar, and a transposition model for the evolution of arsenate resistance in B. subtilis is proposed.

Arsenic↗