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B Andrieu

Publications and source records attributed to B Andrieu.

40 records · Page 3Linked to original sources
PubMed1984

[Plasmodium falciparum: interpretation of the semi-microtest of in vitro chemosensitivity by H3-hypoxanthine incorporation].

Recent advances in cultivation methods and knowledge of in vitro response of Plasmodium falciparum to antimalarials have led to improved chemosensitivity tests. The semimicrotest is a useful tool for screening presumptive antimalarials, and also for the testing sensitivity of strains recovered from patients in hospital and field studies to currently used drugs. Microscopic parasite counts on thin blood films can be replaced by measurement of 3H-hypoxanthine by the uptake parasite. Conditions which ensure optimal parasite growth and high radioisotope incorporation are described. Wells containing less than 3. 10(4) asexual parasites can be studied with this method. Results of the semi-microtest are closely correlated with those of microscopic parasite count. Advantages of both methods are discussed.

Animals↗
PubMed1983

Plasmodium falciparum: drug sensitivity in vitro of isolates before and after adaptation to continuous culture.

Fifteen strains of Plasmodium falciparum have been cultivated since 1979 using the Trager and Jensen method of continuous culture on isolates from malaria patients. One hundred and two drug sensitivity studies have been carried out on these strains using a semimicro test. Three isolates, initially resistant to chloroquine, adapted rapidly to in vitro cultivation and maintained their high level of resistance (ED50 above 660 nM). Eleven isolates, initially chloroquine sensitive (ED50 under 90 nM) became resistant to this drug (ED50 = 190 to 1950 nM) after the 2-15 weeks required for their adaptation to continuous culture. The resistance of these strains never decreased during the following 15 months of continuous culture. The sensitivity to quinine varied initially from one strain to another (ED50 = 160 to 660 nM) and fluctuated during cultivation in the ratio of 1:3.5 for a given strain. The sensitivity of mefloquine remained high for all strains (ED50 under 150 nM) but one (ED50 = 560 nM). These results suggest that there might be a relationship between in vitro adaptation to culture of P. falciparum by the Trager-Jensen method and a chloroquine-resistant characteristic of the strain. There is the possibility of the emergence of a drug-resistant subpopulation or of changes in the metabolic pathways.

Adaptation, Physiological↗
PubMed1982

[Standardisation of the in vitro chemosensitivity test for Plasmodium falciparum ].

Reliable in vitro tests are needed to study the epidemiology, pharmacology, genetics and the treatment of Falciparum malaria. We have studied the reproducible nature of an in vitro method using either patients blood or a continuous strain with which we did 254 chemosensitivity tests with chloroquine, mefloquine and quinine. The method is based on ED50 determination which is done by assessing the plasmodial maturation on thin blood film after 24-48 hours incubation. This method is simple to carryout but long to interpret. It has proved reliable and sensitive enough to be used for the proposed studies. The blood group, the limited variations of erythrocyte concentrations, of the composition and volume of the culture medium, of the atmosphere and of the incubation time had little influence on the ED50. It was considered that 47 p. cent of the tests could be interpreted and that this percentage could be improved with a better understanding of the in vitro behaviour of P. falciparum.

Antimalarials↗