It is unclear, and really no longer relevant, whether the information explosion that we now contend with has been fostered by the growth of specialization and subspecialization in medicine, or vice versa. What is clear is that the two are mutually supportive and constitute what would be in endocrine parlance a short-loop positive feedback system. As a result, for most areas of medicine, even the subspecialist in that area has a problem in maintaining currency, the more general specialist has substan tial difficulty in doing so, and the generalist is tempted to abandon the effort altogether. Nevertheless, for all, both the internal pressures of conscience and self-esteem and the external pressures generated by peer review, recertifi cation, and subspecialty boards create the need for continuous self-educa tion. We are, therefore, in an era in which the means of dissemination of new information deserves as much creative attention as does its acquisition.

In the words of Disraeli, "To be conscious that you are ignorant of the facts is a great step to knowledge. " For most of us, the conscious awareness of relative ignorance is an uncomfortable aspect of daily life. New data appear in such inexorable profusion that the necessity for continuous retooling has joined death and taxes as an inescapable component of our destinies. Perhaps it is this "consciousness of ignorance" that accounts for the success of the preceding volumes of this new series. The Year in Metabolism and The Year in Endocrinology series were introduced with the avowed intention of "providing an efficient and enjoyable bridge between those who are creating new knowledge at the bedside and the professional consciousness of those for whom such knowledge is ultimately intended. " That objective seems particularly appropriate at a time when the award of the 1977 Nobel Prize in Medicine or Physiology to Guillemin, Schally, and Yalow has served to emphasize the epoch-making advances that have characterized the recent course of endocrinology and me bolism. For the 1977 volume of The Year in Metabolism, the previous formula has been preserved. The same internationally recognized authorities again have contributed commentaries about the progress in their areas of expertise. They have been joined by Drs. Jack W. Coburn, David L. Hartenbower, and Charles R. Kleeman, who have provided a new section on Divalent Ion Metabolism.

It is abundantly clear that a number of subtle abnormalities in hypothalamic function are associated with human obesity. Some hormonal abnormalities-the diminished growth hormone responses, for example-are critically dependent on increased caloric intake and are quickly reversible with weight loss. Others, such as the blunted prolactin response to acute hypoglycemia, may persist in the reduced-obese state. Still others (e. g. , the blunted ACTH responses to insulin induced hypoglycemia) may, in some patients, first appear in the reduced-obese state. It remains uncertain whether any of these abnormalities is ever antecedent to the presence of obesity. Obviously, it is difficult to plan experiments in which the amounts of stored triglyceride, the level of caloric intake, and the state or his tory of obesity can all be individually evaluated. The issue is made even more complex by the fact that there may be subgroups of obese in whom hypothalamic function may be abnormal, whereas many obese may have nearly normal hypo thalamic function. It should be remembered that for years clinicians and investigators, working with available research tools, have ruled out pituitary or hypothalamic abnor malities as a cause of human obesity. These tools have oftentimes been no more sophisticated than skull roentgenograms and samples of excreted steroid hormones in 24-hr urine. The advent of radioimmunoassays for peptide hormones and the availability of synthetic releasing hormones have offered possibilities of studying hypothalamic function undreamed of just a few years ago.

Despite a new title, Contemporary Metabolism, Volume 1 is actually the third volume in a continuing series and succeeds The Year in Metabolism 1975- 1976 and The Year in Metabolism 1977. As in the earlier volumes, the same internationally recognized authorities review the noteworthy recent devel opments in their areas of expertise. In many instances they also address aspects that have not been considered previously. In this volume, Dr. J. Edwin Seegmiller again updates progress in understanding disorders of purine and pyrimidine metabolism. However, particular emphasis is placed on the emerging relationships with immune mechanisms. Dr. Charles S. Lieber is joined by Dr. Enrique Baraona in a continuing review of metabolic actions of ethanol. This chapter examines effects of ethanol on protein metabolism and selected features of lipid metabolism-two areas that were not included in the earlier volumes. Dr. DeWitt S. Goodman's review of disorders oflipid and lipoprotein metabo lism builds on his previous chapters, but much additional attention is directed to a critical analysis of recent advances in epidemiology and lipoprotein structures. In collaboration with Dr. Brian L. G. Morgan, Dr. Myron Winick devotes his entire chapter to a detailed review of the impact of nutrition upon brain development-an overview that has now been rendered possible by the burgeoning recent developments in this area."