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Biomedical subjects

M E Saunders

Publications and source records attributed to M E Saunders.

7 recordsLinked to original sources

Interferon-regulated human 2-5A synthetase gene maps to chromosome 12.

The low-molecular-weight human 2-5A synthetase gene has been assigned to chromosome 12 using rodent-human somatic cell hybrids and filter hybridization analysis of cell hybrid DNA. A cDNA probe representing almost all the coding sequences of the 2-5A synthetase gene hybridizes to four fragments of human DNA digested with the restriction enzyme EcoR1. By correlating the presence of these fragments in somatic cell hybrid DNA with the human chromosome content of the hybrids, the 2-5A synthetase gene can be mapped to chromosome 12. This contrasts with a previous assignment of this gene to chromosome 11 using an enzyme activity assay. The reason for this discrepancy remains unclear.

Animals

Human 2-5A synthetase: characterization of a novel cDNA and corresponding gene structure.

The enzyme 2-5A synthetase is induced in cultured cells in response to interferon (IFN) treatment. A lambda gt10 cDNA library of mRNA from IFN-induced Daudi lymphoblastoid cells was screened with oligonucleotide probes. Several overlapping cDNAs were isolated and shown to be derived from the human synthetase gene using filter selection and oocyte microinjection assays. The nucleotide sequence of one of these, cDNA 8-2, extended the 2-5A synthetase sequence already described 72 bp in the 5' direction but was found to differ significantly in coding sequence at the 3' end. The longest cDNA isolated (6-2) was approximately 1.4 kb. By Northern hybridization analysis single mRNAs of 1.7 kb were detected in Daudi and T98G (glioblastoma) cells. However, in HeLa cells, four mRNAs ranging in size from 1.5 to 3.5 kb were found, one of which differed at the 3' end. Analysis of both phage and cosmid genomic clones and comparison with genomic DNA indicate that there is a single gene for 2-5A synthetase, comprising at least six exons and five introns, which can undergo a novel form of alternative RNA processing depending on cell type.

2',5'-Oligoadenylate Synthetase

The neurotoxicity of misonidazole and its relationship to dose, half-life and concentration in the serum.

Misonidazole has been given to a total of 87 patients. Neurotoxicity has occurred--convulsions with the higher doses and peripheral neuropathy with the lowern ones. The data from 34 patients receiving 4--7 doses has been analysed. Peripheral neuropathy is related to the total tissue exposure. By monitoring serum levels and controlling the total dose given, convulsions are avoidable and peripheral neuropathy restricted to a low and acceptable level.

Drug Administration Schedule

Inhibition of a lymphocyte membrane enzyme by delta9-tetrahydrocannabinol in vitro.

Delta-9-tetrahydrocannabinol (delta9-THC) inhibited the activity of lysolecithin acyl transferase, a membrane-bound lymphocyte enzyme, at concentrations above 1.3 muM. Stimulation of acyl transferase activity by concanavalin A, an early response in lymphocyte activation, was entirely abolished in the presence of delta9-THC.

1-Acylglycerophosphocholine O-Acyltransferase