Topics in Hematology – serie

Each year, it becomes more apparent that trace elements play an important role in human metabolism. The concept is no longer new. The literature on the subject is voluminous. Dr. Prasad, who has been interested in this field for many years, has undertaken the enormous task of bringing our knowledge together in a comprehensive fashion. This monograph should prove very informative and extremely useful to everyone who is concemed with human disease and with the maintenance of good health. His coverage of the subject is broad. Because ofthe importance of iron, in addition to "trace" elements, in human metabolism and nutrition, a chapter dealing with iron has been included. Maxwell M. Wintrobe, M.D. vii PREFACE It has been known for several decades that many elements are present in living tissues, but it was not possible to measure their precise concentra­ tions until recently. They were therefore referred to as occurring in "trace" amounts, and this practice led to the use of the term "trace elements." Although techniques now available are such that virtually alI trace elements can be determined with reasonable accuracy, the designation "trace ele­ ments" remains in popular usage.

Each of the four authors of this book has a particular interest in disorders of porphyrin metabolism and special experience in their management. Their individual involvement in the field varies from 12 to 52 years and, combined, represents more than a century of personal experience. Since it has been written by both basic scientists and practicing physicians, the book is intended to be of value to all those involved in porphyrin metab­ olism and the porphyrias. It is hoped that the fascination of porphyrin metabolism and the clinical challenge of the porphyrias experienced by each of the authors will be conveyed to the readers. Michael R. Moore Kenneth E. L. McColl Claude Rimington Abraham Goldberg vii CONTENTS Color Plates ............................................ xvii 1. The History, Classification, and Incidence of the Porphyrias 1 1.1. History ........................................ 1 1.1.1. Early Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1.2. Early Descriptions of Porphyria .............. 4 1.1.3. Biochemical Developments .................. 4 1.1.4. Acute Porphyria . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.1.5. A Complete Pathway ...................... 8 1.2. Classification of the Porphyrias . . . . . . . . . . . . . . . . . . . . . 9 1.2.1. The Current Classification. . . . . . . . . . . . . . . 12 . . . .

This monograph is the first of a series which is designed to present in depth timely reviews of subjects related to the blood. Insofar as each subject lends itself, the clinical aspects of each topic will be presented as fully as is appropriate, in addition to the basic features. As a consequence, the various monographs should be found useful not solely by hematologists. Depending on the nature of each topic, it is expected that these monographs will be found important by physiologists and specialists in fields other than hematology, as well as by scientists of very diverse interests. The present treatise illus­ trates this point. Doctors Garby and Meldon have brought together in a most useful way the spectacular advances which have been made in the last decade or two in a field of fundamental biologic impor­ tance. They have also brought to the discussion of this subject their own observations and interpretations as well as their profound understanding of the respiratory functions of the blood. Maxwell M. Wintrobe Salt Lake City, Utah v Preface This volume is an attempt to summarize the present state of know­ ledge of the respiratory functions of blood in health and disease. Though it deals fairly thoroughly with physicochemical aspects of the blood's gas transport properties and with the molecular chemis­ try of hemoglobin, its main emphasis is the gas transport function of the blood in vivo and modes of its disturbance in disease.

"People . . . see you sweat in agony, turn pale, turn red, trem­ ble, vomit your very blood, suffer strange contractions and con­ vulsions, sometimes shed great tears from your eyes, discharge thick, black and frightful urine, or have it stopped up by some sharp rough stone that cruelly pricks and flays the neck of your penis. " * These 16th century frustrations of Michel de Montaigne which most graphically reflect his experience with renal colic still plague approximately 1 per 1000 individuals in the United States annually. Since as many as 75% of clinically. apparent episodes of renal colic represent single nonrecurring events, physicians not in­ frequently approach the differential diagnosis of nephrolithiasis in a less than adequate fashion and assume that the incident may prob­ ably never recur after the single attack. However, the ureteral or bladder stone actually represents one form of abnormal crystalline precipitation; parenchymal nephrocalcinosis, silently progressive azotemia, and asymptomatic renal pelvic calculi may also stem from the same pathological process(es) which conditioned the for­ mation of the ureteral or bladder stone. In this regard it is worth emphasizing that the postmortem incidence of renal calculi is some tenfold greater than that presumed from surveys wherein a clinical attack of nephrolithiasis is the sole determinant. *In Familiar Medical Quotations. M. B. Strauss, Ed. Little Brown, Boston, 1968, p. 646. v vi FOREWORD The last decade has witnessed the birth of new knowledge in urolithiasis research.