Recherches sur l'expression des facteurs létaux héréditaires chez l'embryon de la drosophile

Résumé Les variations du volume du protoplasme pendant le développement ont été suivis chezD. virilis etD. melanogaster. Le protoplasme de l'uf fraîchement pondu remplit la membrane vitelline; bientôt, il se produit une contraction de volume, et il se forme un ellipsoïde. Le protoplasme continue à sa contraction pendant quelque temps, puis il se produit à une augmentation de volume. La projection des cellules polaires se fait immédiatement après cette augmentation. Celle-ci est élevée après la formation des cellules polaires et le volume atteint alors un maximum. Pendant cette période, la formation du blastoderme s'accomplit. Ensuite, pendant la période de la formation de la gouttière ventrale, le volume de l'embryon se réduit à nouveau; mais cela la contraction se limite à la partie céphalique seulement. Dans l'embryon létal nullo X, la contraction et l'augmentation de volume se font comme dans l'embryon sain, bien que les noyaux n'exécutent pas leur migration centrifuge. La relation entre la variation de volume et la migration des noyaux est discutée.     

Chimiothérapie des tumeurs germinales du testicule

Germ cell tumours of the testis represent a model of curable disease, even in advanced stages. Cisplatinbased combination chemotherapy followed by surgical removal of residual metastatic disease has dramatically improved the prognosis of these patients, as about 90% of them are currently cured. The standard cytotoxic drugs used in first-line treatment are bleomycin, etoposide and cisplatin (the so-called BEP regimen). Treatment strategy is based on assessment of risk factors. Three cycles are generally used in patients with advanced pure seminoma or good-risk metastatic non-seminomatous tumours. Four cycles are required in patients with intermediate-or poor-risk metastatic non-seminomatous tumours, while two cycles of BEP constitute a safe and effective treatment option in early-stage tumours but with a high-risk of metastatic spread defined by a high percentage of embryonal carcinoma and/or the presence of vascular invasion. Cure rates as high as 90% are achieved provided risk factor strategies are accurately applied and standard treatment modalities are respected. All protocol violations can decrease the expected efficacy or induce unnecessary toxicity.     

Une méthode d'amplification génique isotherme

A gene amplification technique applied to the detection of HIV and which can be implemented without programmable thermocyclers is described. The reaction products are high molecular weight strands of DNA that can be detected using simple methods, even without electrophoresis. This is a promising technique for in situ amplification experiments. Our findings show that this amplification method is compatible with the temperature levels encountered in living cells. This technology could thus be the basis for a new class of drugs intended for treatment by gene therapy of certain diseases, including malaria and AIDS.