[Conceptual framework for research applied to the health services].

The authors draw up a conceptual framework for applied research on health services based on the experiences of the Division of Health of the Department of Social Medicine of the Universidad del Valle, Cali, Colombia. They hope that by using this framework, people involved will be able to situate themselves in a process of this type, interpret the current role of research on health services and examine the approach that should be taken to it in the future. They bring in some elements of self-criticism in the hope of contributing to the development of research groups in this area.

Preparation of some prostaglandin E1 and omega-homo-prostaglandin E1 esters and their inhibiting properties on rat blood platelet aggregation.

Various esters of omega-homo-prostaglandin E1 and prostaglandin E1 were prepared in a yield of 28-55% to investigate their effect on ADP-induced aggregation of rat blood platelets. The biopotency of the omega-homo-PGE1-esters is about four times higher than that of the corresponding PGE1-esters. Furthermore, the biopotency of aliphatic esters decreases with increasing chain length of the ester group.