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Biomedical subjects

R Buchanan

Publications and source records attributed to R Buchanan.

81 records · Page 5Linked to original sources
PubMed1974

Determination of plaque inhibitory activity of adenine arabinoside (9-beta-D-arabinofuranosyladenine) for herpesviruses using an adenosine deaminase inhibitor.

The in vitro susceptibility of type 1 and type 2 strains of Herpesvirus hominis to 9-beta-d-arabinofuranosyladenine (adenine arabinoside, ara-A) was measured in a system where deamination was inhibited. Under these conditions, it was possible to measure the activity of low concentrations of ara-A. It was determined that plaque inhibitory concentration for type 1 viruses was less than 3 mug/ml for all strains tested. The plaque inhibitory concentration for 7 of 10 type 2 strains was also less than 3 mug/ml. The method used identified and controlled the interaction between antiviral agent (ara-A) and the indicator system, human skin fibroblastic cells. Otherwise, metabolism of ara-A resulted in rapid enzymatic degradation and loss of antiviral activity.

Adenosine Deaminase Inhibitors↗
PubMed1974

Effect of adenosine deaminase upon the antiviral activity in vitro of adenine arabinoside for vaccinia virus.

This study determined that the effect of 9-beta-d-arabinofuranosyl-adenine (adenine arabinoside, Ara-A) upon vaccinia virus plaque development in the stable monkey kidney line, LLC-MK(2), was increased approximately 40-fold when an inhibitor of adenosine deaminase (ADA) was added to the tissue culture media along with infective inocula. The concentration of Ara-A required to completely suppress plaque development (total plaque inhibitory concentration(100); TPIC(100)) was greater than 10 mug/ml. However, when ADA activity was inhibited, the TPIC(100) was 0.5 mug/ml or less. Chromatographic assay of arabinosylpurines in the media provided evidence that adenine arabinoside was rapidly deaminated to 9-beta-d-arabinofuranosylhypoxanthine by the cellular monolayers, in the absence of animal serum, and that the rate of deamination, at 5 mug/ml, by the cells was equal to the rate of diffusion of Ara-A across the cellular membrane. The half-life of Ara-A in the media, starting with 5 mug/ml, was 2 to 3 h and shorter at lower concentrations. The study demonstrates the profound effect that an indicator system, acting as an intact biological unit, can have upon a potential antiviral compound.

Adenosine Deaminase↗
PubMedDate not supplied

Caring centre questioned.

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Attitude of Health Personnel↗
PubMedDate not supplied

Vidarabine therapy of simple and IDU-complicated herpetic keratitis.

Large scale, multiclinic evaluations of vidarabine (Ara-A, Vira A, adenine arabinoside) for treating herpetic keratitis have been conducted as double-blind studies (169 patients) in comparison with IDU and open studies (146 patients). In the open studies, the disease in the majority of patients had been refractory to IDU. The effects of vidarabine and IDU were approximately the same in improvement of symptoms (lacrimination, photophobia, sensitivity) and percent of and time for corneal reepithelialization. With vidarabine, significantly more patients had improved distant visual acuity than did with IDU. In the open studies, vidarabine also was effective. Of 116 patients whose ulcers had not responded to IDU, 91 (78%) had reepithelialization within four weeks of treatment with vidarabine. On the basis of results from these studies, vidarabine appears to be a safe and effective drug for treating herpes simplex keratitis.

Adolescent↗