Jacqueline Gruest

A new type of retrovirus isolated from patients presenting with lymphadenopathy and acquired immune deficiency syndrome: Structural and antigenic relatedness with equine infectious anaemia virus

Summary Further characterization of a human lymphotropic retrovirus previously isolated from a patient with lymphadenopathy syndrome is reported. The virus is not antigenically related to human T-cell leukaemia virus (HTLV1). The mature virions have a distinct morphology when examined by electron microscopy, with a small eccentric core. This morphology is close to that of equine infectious anaemia virus (EIAV). Moreover, the p25 protein of the human isolate can be immunoprecipitated by sera of horses infected with EIAV. Similar viral isolates have been made from several patients with acquired immune deficiency syndrome (AIDS). Antibodies to such viruses are widely distributed in patients having AIDS or at risk of AIDS.

Synchronisation de cellules BHK 21 par carence partielle en l-asparagine

Abstract The isolation of mutants requiring l -asparagine from a population of BHK 21/13 cells has enabled us to synchronize the cell growth using the deprivation effect of this amino acid. In the absence of asparagine, cells cannot enter a new cycle of DNA synthesis and accumulate in G 1 phase, If asparagine is added to 24 h growth-arrested cultures, a wave of DNA synthesis is observed after a 6 h latency period, followed by a partially synchronous cell division reaching a 55% labelling index. During a 24 h period, in the presence of very small amounts of asparagine (1 to 6 × 10 −6 M) a higher cell fraction accumulates at G 1 period. In these conditions the degree of synchronisation is improved, reaching an 85% labelling index, following a 24 h incubation in the presence of 6 × 10 −6 M asparagine.

A new purine analogue with antimitotic activity

Abstract The compound 4-benzylamino 6-methyl 7-benzyl pyrrolo [2,3-d] pyrimidine has been found to arrest cultured cells in metaphase. The block can be released upon removal of the drug. However, after prolonged incubation with the inhibitor, some irreversible effects occur, such as anarchic reconstruction of the nuclear membrane around dispersed chromosomes and formation of multinucleated giant cells. In addition, the drug has some effect on the shape of interphase or resting fibroblasts and on mitochondria. Most of these effects can be explained as action at the level of microtubule organization.