You see things, and sa)' why? But I dream 1hings that never were, and I say, 11'hy 110t? George Bernhard Shaw Far ahead of his time, June 1st, 1909, Alexander Maximov communicated in a lecture, given in the Charite in Berlin, the fundamental knowledge, that there exists a lymphoid hemopoetic stem cell. Alexander Friedenstein explained that during the following years, Maximov also showed that the idea of interaction between hemopoetic cells and their stroma to be one of the most significant experiences. Monoclonal antibodies, recombinant DNA technics and the improvement of tissue culture models are the major developments to improve our possibilities to clarify growth and differentiation functions of hemopoetic cells. During the last two decades it was shown that soluble products, released from T cells, were not only involved in inducing B cells to produce specific immunoglobulin secretion after antigen stimulation. Furthermore, lymphokines together with other cytokines regulate the growth and differentiation of hemopoetic cells. As I have learned from Dick Gershon, our knowledge of the cellular basis for immunoregulation has come a long way since 450 B.C. Thucydides comments on the possible role of immune response in controlling the Black Death. Dick Gershon speculated that no scientific interest for these interesting observations was put forth at that time. Perhaps the problems, the Athenians were having with the Spartans, converted money from basis research into the military budget.

Gut ist eine Lehrart, wo man vom Bekannten zum Unbekannten fortschreitet; schon ist sie, wenn sie sokratisch ist, d.i. wenn sie dieselben Wahrheiten aus dem Kopf und Herzen des Zuhorers herausfragt. Bei der ersten werden dem Verstand seine Uberzeugungen in Form abgefordert, bei der zweiten sie ihm abgelockt. Professor Friederich Schiller Jena, in a letter written on 23 February 1793 to his friend and supporter Korner, father of the poet Theodor Korner. Established clinicians and scientists as weil as students aga in tried the Wilsede experiment for three days and nights and learned from each other. In our fourth Wilsede meeting on "Modern Trends in Human Leukemia" we concentrated once again on questions re gar ding the practical application of research and its benefits to the patient. The main emphasis of leukemia research has changed since the first Wilsede meeting in 1973. Virology is no longer the sole interest. Advances in immunology and cell genetics and a better understanding of Dr. h. c. Alfred Toepfer speeking with participants of the meeting in Wilsede XXI Arrival and discussion of participants in front of the meeting pI ace "De Emmenhoff" XXII Personal and scientific discussion in Wilsede June 1980 Fotos: R. Vols XXIII the mechanisms regulating normal and pathological blood cell differen tiation have had a considerable impact on the direction of leukemia research."

mene Stil in jeglicher Kunst, daft er die spezijischen Schranken derselben zu entfernen weip, ohne doch ihre spezijischen Vorzuge mit aufzuhe- ben, und durch eine weise Benut- zung ihrer Eigentumlichkeit ihr einen mehr allgemeinen Charakter erteilt. Friedrich Schiller - Ober die as the- tische Erziehung des Menschen. In den Horen, 22. Brief (1795) We are glad that you have all come to this small village and I hope that you will feel at home here for the next few days. The special atmosphere of the surround- ings will probably have a good influence on our discussions, and you will perhaps remember this when you are back home again. It takes hard work to save this little piece of nature for man in our highly industrialized world, and we should all be grateful to the Verein Naturschutzpark e. V. (founded in 1909), Alfred Toepfer and his associates for their efforts. We intend to discuss modern trends in human leukemia in this workshop, but we should also take the opportunity to reflect on the trends of the past, which might still be modern.