Methamphetamine is one of the most widely abused stimulants and together with amphetamine has led to serious social problems. Numerous papers in the fields of medicine, toxicology, pharmacology, sociology, etc. have appeared. In Japan for example about 20,000 to 22,000 persons have been arrested in recent years on suspicion of abuse, smuggling or illegal manufacture of drugs. In other countries, stimulant drugs also present social problems and efforts have been directed toward prevention. Although marked development of analytical techniques in the field of forensic sciences has been achieved, there is a need for a continuous review of recent advances. A review of studies on methamphetamine has therefore been made from the standpoint of forensic toxicology and legal medicine. Attention has been directed to biological samples because analyses and interpretation for the purpose of t.oxicological and As a detailed survey on abuse drugs involving clinical practice are important. 1 methamphetamine and amphetamine has been made by Fishbein and covered the time before 1980, we refer only to data and events appearing after 1980.

A number of years ago Prof. J. Peiffer (Tiibingen/FRG) asked whether cerebros- nal fluid cells originate in blood cells. With this question, the first seeds were sown for the research which resulted in this book. The original question was eventually ex- panded to whether extravascular hematogenous cells are present in the nervous sys- tem. In the course of my research this question became more and more concentrated on the demonstration of monocyte derivatives (i.e., mononuclear phagocytes) within the nervous system. While these questions are certainly not new, they regularly crop up when micro- glia are to be classified, particularly progressive microglia. Three extensive surveys were published during the past few years, all of which arrived at different conclusions (Cammermeyer, 1970b; Vaughn and Skoff, 1972; Fujita and Kitamura, 1976). In ad- dition to progressive microglia, other active phagocytes were observed which I refer to as "perivascular cells," "free subarachnoidal cells," and "epiplexus cells." These cells were seldom described in the literature, and then predominantly in another context. A pre- sentation based on the hypothesis that the cell types of the central nervous system have po- tentially identical kinetics and functional potency has not been published.