Bone marrow suppression and severe anaemia associated with persistent Plasmodium falciparum infection in African children with microscopically undetectable parasitaemia

In sub-Saharan Africa the highest overlap between malaria and HIV infections occurs in female adolescents. Yet control activities for these infections are directed to different target groups, using disparate channels. This reflects the lack of priority given to adolescents and the absence of an accepted framework for delivering health and health-related interventions to this high-risk group. In this paper it is argued that female adolescents require a continuum of care for malaria and HIV – prior to conception, during and after pregnancy and that this should be provided through adolescent services. The evidence for this conclusion is presented. A number of African countries are commencing to formulate and implement adolescent-friendly policies and services and disease control programs for malaria and HIV will need to locate their interventions within such programs to ensure widespread coverage of this important target group. Failure to prioritize adolescent health in this way will seriously limit the success of disease control programs for malaria and HIV prevention.     

The Growth Physiology of Coleoptiles in Continuous-Record Vessels: Anomalous Kinetics of Cycloheximide Action on Auxin-Controlled Growth

The interacting effects of auxin and cycloheximide upon the growth of Triticum coleoptiles depends upon the incubation conditions. In the growth vessel developed by Evans and Ray (1969) the action of cycloheximide is severe and the growth kinetics show a rapid nullification of auxin action by the inhibitor; hormone action is also totally prevented by a relatively short period of pre-treatment with cycloheximide. The kinetics of response to the two substances are quite different when coleoptiles are floating on the test solutions; here, cycloheximide is much less severe in its action. These differences are due to a heightened sensitivity to cycloheximide induced by exclusion of the air bubble from the coleoptile cylinder in the Evans and Ray chamber. The outer surface of the coleoptile wall is a less efficient respiratory surface than the inner one. When coleoptiles are filled with a stagnant solution insufficient oxygen can be taken up through the inner surface and the tissue therefore suffers oxygen deprivation. This exacerbates the action of cycloheximide as a potent respiratory inhibitor. The results raise questions concerning the use of conditions in which coleoptile sections are filled and submerged, which is a feature of recently introduced continuous-record growth vessels. In particular, interpretation of the interactions between cycloheximide and auxin under such conditions must be made cautiously.