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Biomedical subjects

R G Wilson

Publications and source records attributed to R G Wilson.

At least 145 records · Page 8Linked to original sources
PubMed1976

Drug screening in cell culture for the detection of anticoccidial activity.

Methods for screening compounds against Eimeria tenella in cell culture and in the chicken are described. An analysis for incidence of anticoccidial activity and host cell toxicity has been made of 11550 compounds screened in vitro, and some correlation of activity in vitro and in vivo has been attempted. The results show that screening compounds in tissue (cell) culture is not a satisfactory or reliable alternative to screening in chickens, although in vitro studies undoubtedly have a part to play in the evaluation of an active drug.

Animals↗
PubMed1976

Studies on short-term application of drugs to Eimeria tenella in tissue culture.

The anticoccidial action of 6 drugs was studied by treating cell cultures with drug for 24 h after inoculation of the cultures with sporozoites of Eimeria tenella. A monitoring technique was used to confirm that the drug was being removed. Only monensin was shown to be coccidiocidal. Amprolium, lasalocid, methyl benzoquate, nicarbazin and robenidine were coccidiostatic at their minimum effective doses. Misleading coccidiocidal effects were observed when higher concentrations of methyl benzoquate, nicarbazin or robenidene were used.

Amprolium↗
PubMed1976

Laboratory studies with some older anticoccidials.

Features of the anticoccidial activity of nicarbazin, amprolium, zoalene, sulphadimidine, diaveridine, Darvisul, spiramycin, chloramphenicol and oxytetracycline have been re-investigated both in vivo and in cell culture using Eimeria tenella. Of the drugs studied, only spiramycin was appreciably coccidiocidal, although nicarbazin and amprolium showed possibly slower coccidiocidal activity. In order to show activity against a particular stage in the life-cycle, higher concentrations of drug than those usually recommended for field usage had in most cases to be used. Under these conditions, parasites were usually inhibited as multinucleate 1st generation schizonts. With delayed medication, effects against 2nd generation parasites were in most cases found, and in many cases, although the parasites never matured to give viable merozoites, the large degenerating forms produced were able to cause extensive tissue destruction and haemorrhage. Methodology in this type of study is discussed in relation to more active and more recent anticoccidials, and some further experiments with robenidine reported.

Amprolium↗
PubMed1975

Inhibition of macromolecular synthesis in L1210 mouse leukemia ascites cells by hycanthone.

Hycanthone inhibits macromolecular synthesis in L1210 cells. At the same concentrations of hycanthone, DNA synthesis is inhibited to a greater extent than the synthesis of RNA. There is an inhibition by the drug of the synthesis of ribosomal precursor RNA; the synthesis of other types of RNA including heterogeneous and small-molecular-weight, also appears to be inhibited. Maturation of 45-S RNA does not seem to be affected, and there is a partial reversal of inhibition of both DNA and RNA synthesis by washing the cells free of hycanthone.

Animals↗
PubMed1975

Laboratory studies with some recent anticoccidials.

The activities of monensin, lasalocid and halofuginone against Eimeria tenella, E. brunetti and E. necatrix have been studied under laboratory conditions. Complete control of experimental infections in the chick, separable from toxicity, was not obtained with monensin, but was achieved with the other two compounds at levels of 150 and 6 ppm in the food respectively. All three compounds appear to inhibit coccidial development very early in the life-cycle, and to have a fairly rapid lethal effect, monensin and lasalocid more so than the febrifugine derivative. In vivo observations have been supplemented with in vitro studies. Some discussion of the difficulties of relating laboratory experiments to field performance is given.

Administration, Oral↗