Annual Review of Pharmacology

Ian Leslie has presented an interesting theory of messenger RNA structure and function, drawing on microbial and tissue culture cell populations, and acutely emphasizing the operational similarities between these two systems. Briefly, Leslie argues for the coding of RNA messenger from both of the complementary DNA strands. Histone protein plays the crucial and very speculative role of selectivity, stabilizing one strand while inactivating the other. The theory, while exciting and closely reasoned, suffers from the selected nature and paucity of the data used to support it. Harry Eagle's very short article is nevertheless of interest. Most important are Eagle's findings that certain cell populations can grow in the absence of serine at high concentration; however, since serine leaks irreversibly from cells at low concentration, it must be added in order to sustain growth. These findings help to place in perspective earlier observations showing the need to use conditioned medium when initiating cultures at a low inoculum. Such studies will certainly make important contributions to the maintenance of small populations. Samuel Graff describes investigations on the technique of producing large populations of mammalian cells with the cyto-generator, and discusses the effect of pH, gas phase, and hormones on growth rate. Graff disputes the importance of CO2 as a nutrient in these systems, but omits reference to the work of Harris and others who provide positive evidence for such a requirement. Lastly, Robert Auerback presents varied observations relating to the inductive interaction of stromal and parenchymal components of various organs. Dr. Auerback has followed the work of Grobstein relating to the inductive effect of stroma on parenchyma differentiation. He has been able to assess modifications of post inductive differentiation of parenchymal cell populations by cultivating them as dispersed populations for varying lengths of time in vitro or by causing them to pass through a disaggregationreaggregation cycle. The selections are concluded by remarks by Wilton Earle, but no real attempt is made to review and integrate the preceding articles. Dr. Green, as editor, has made the error of selecting too large a subject, and one which is ill defined. Because of this, most individuals working on problems involving tissue culture techniques will not find this volume of more than passing interest. This is especially so since many of the experiments reviewed are more fully reported elsewhere. The symposium particularly suffers from a failure to integrate and deal with inconsistencies between the individual papers. For example, there is a frank disagreement on optimal pH with respect to maximal growth rate between the data of Drs. Paul and Graff. FRANK H. RUDDLE