Thoughts on future relationships between physicians medical students and citizens walter bauer memorial lecture.код для вставкиСкачать
Arthritis and Rheumatism APRIL, 1965 VOL. VIII, NO. 2 Thoughts on Future Relationships between Physicians, Medical Students and Citizens (Walter Railer Memorial Lecture) By HALSTED R. HOLMAN I DID NOT IN ANY real sense know Walter Bauer personally, though I met him on occasion late in his life. I know him, however, in the way most in medicine know him, as a leader in medical eduction. I also know him by knowing his associates and students and realizing the ways in which he influenced them. Two outstanding features of Walter Bauer’s life strike me: his incessant effort to improve medicine and medical education, in particular by demanding the highest quality of performance from young people while simultaneously giving them large amounts of responsibility, and his willingness to go beyond the conlentional in thinking and acting in medical affairs. This is hardly an adequate summation of the heritage which he left us, but if we all were to emulate these characteristics successfully, perceptible improvement would occur. It is indeed an honor to give the Walter Bauer Memorial Lecture. The past decade has witnessed a concerted effort to make the study of arthritis and rheumatic diseases a scientific endeavor. Significant accomplishments can be measured. These years have seen (1) the discovery of autoimmunity and confirmation of the suspicion that immunological abnormalities play a role in rheumatic diseases, ( 2 ) the emergence of evidence indicating a hereditary susceptibility to rheumatic diseases and ( 3 ) the appearance of relationships between rheumatic diseases and other illnesses with identifiable immunological abnormalities such as lymphomas. The study of the rheumatoid factor and of mveoloma proteins has led to beginning understanding of the structure of gamma globulin and the genetic control of its synthesis. Because of techniques developed in the aforementioned studies, it is now possible to begin the search for individuals who are susceptible to rheumatic diseases, thus hopefully permitting introduction of preventive measures. The emergence of immunology as a major discipline for the study of human biology has been central to these developments. Immunological techniques and concepts have not only shed light on rheumatic diseases but promise to do so on many biological and clinical problems ranging from embryogenesib and cell differentiation to oncogenesis. 183 ARTHRITISAND RHEUMATISM,VOL. 8, No. 2 (APRIL), 1965 184 HALSTED R. HOLMAN It would be appropriate to speak about these developments. In an oblique sense, I shall. However, the transformation of medicine into a scientific discipline, to which the study of rheumatic disease has contributed, raises many relevant issues for the physician and the medical teacher. I cannot resist the temptation to speak about two. They are, first, the adequacy of current medical education for training the physician for the future and, second, future relationships between the medical profession and the citizens. Thc vision of one who attempts to peer into the future cannot be validated by others at the time. What he perceives is quite subjective, and may contain more than a trace of the prejudices of the seer. Furthermore, the above issues are difficult to understand with clarity. However, they are of the greatest importance; we have no choice but to examine them. Before speaking on these subjects, some consideration of the current state of medical science and its potentialities is relevant. Today the provision of medical care is one of the largest industries in the country. In 1964, the total cost of medical care in the United States will approach 33 billion dollars exclusive of the loss of income resulting from illness and death. Proportionately many more citizens avail themselves of medical care now than in the past. Techniques of medicine have increased considerably in number, scope and expense. But, if one asks what is the state of the art so sought after and so expensive, we must answer that it remains relatively primitive when compared to what it can and will become. Though the diagnostic skills of the physician have become quite good, his Gbility to understand the disease process and to intervene meaningfully to terminate it are grossly inadequate. The causes of such major illnesses as cancer, cardiovascular disease, mental illness and arthritis remain obscure. In the absence of knowledge of the cause of an illness, it is unlikely that a highly eflective therapy will be available. None is for the aforementioned illnesses. True, we have ways of helping the patient by the use of drugs, surgery, supportive measures and sympatliy. The drugs which are used, however, were discovered by chance. Their methods of action are usually not known, the ways in which we use them have been arrived at pragmatically, and they are not very effective. Indeed the mechanisms of action of three of the most important drugs known to man, aspirin, digitalis and morphine, are unknown, and the actions of a fourth, penicillin, are merely beginning to be understood. Our ignorance is all the more apparent when dealing with the questions of normal life and health. The processes of conception, growth, development, learning, maturation and senescence remain unexplained. Thus, despite the seemingly good care we are able to provide in a modern hospital, in an absolute sense the quality of medical care is poor. However, the capabilities of the physician may soon undergo a dramatic increase. The rapid delielopments in biological sciences since the 1940s are beginning to have a major impact on medical knowledge. The ways in which information is passed from parent to offspring cell are becoming known. The processes responsible for the development of the complex mammalian body from two original cells are now amenable to study. Some of the factors which PHYSICIANS, MEDICAL STUDENTS AND CITIZEN RELATIONSHIPS 185 control cell growth, and go awry in cancer, can now be fruitfully explored. The ways in which a virus or a bacterium affect another cell are being identified and, very recently, mechanisms of action of a variety of antibiotics have been discovered. The process of learning by brain cells is now susceptible to study. Control of the immune response to the point of permitting transplantation of tissues between unrelated individuals is in the offing. Application of this new knowledge to the study of disease will almost certainly begin to lay bare the biological processes whereby we becomme iI1. Such an understanding would then permit for the fist time, the design of medical treatment aimed at correcting the abnormalities which lead to disease. If this should not prove feasible, it may be possible to substitute a norma1 or even a mechanical organ for one which is diseased. These anticipated developments in medicine are likely to occur in the context of major changes in the society in which we live. These changes will also affect health and our ability to provide medical care. The availability of- energy from nuclear and solar sources, coupled with automatic production techniques, may have extraordinary consequences. The magnitude of the energy potentially available can be seen from the fact that once nuclear fusion (the process involved in the hydrogen bomb) has been controlled for peaceful purposes, 230 cubic meters of heavy water will provide the energy now obtained from the entire annual coal output of the world. Harnessing one-tenth of the wasted solar energy which strikes the earths surface could provide industrial energy many times the total now generated throughout the world. The availability of nuclear power sources of small size will permit the construction of industry at virtually any place on the earth‘s surface, eliminating the necessity of building or maintaining industry near sources of fossil fuel or transportation networks. Automatic production methods will greatly increase productivity, reduce the need for continuous supply of manpower and thus reduce one of the major reasons for development of large cities near industry. Decentralization of both industry and population will be economically feasible and indeed it may become possible and desirable to rebuild the face of the country. The eradication of poverty and slums with their disease breeding consequences will be possible. Rapid transportation will bring the best medical care within physical reach of everyone. The next decade or more will likely witness the emergency of a new era in the history of man, marked by man’s development of the ability to control both his environment and himself. In addition to many extraordinary advantages, dangers will accompany this assumption of power by man. As we begin to alter nature more and more, there will be an increasing threat that our environment will be made harmful to us by our own actions. The use of radioactive materials brings with it ths problem of disposal of radiwctive wastes and potential environmental contamination. The same is true for the use of poisons in pesticides, detergents in cleansers and many other products of the growing chemical industry. The citizens, whose lives will be directly affected, will have a large role to play in shaping government policy on the use of new technological skills. 186 HALSTED R. HOLMAN They will have much to learn in order to fulfill that role. I should like to speculate on some of the implications of these developments for the physician. A far more advanced and complex understanding of human biology will require that the physician be a thoroughly trained scientist in order to comprehend the problems of his patient and the available methods of treatment. The power to alter heredity, to change brain function and to change an individual physically by transplantation of tissues, a11 of which are potentially possible, will add enormously to the responsibilities of the physician to the patient. Rarely in the past, or even today, have we had at our command techniques which of and by themselves could radically alter the function and life of the patient. The physicians of the future will. No longer will they use a dangerous drug virtually only when confronted with a hopeless situation, usually with negligible likelihood of success. Treatment in the future may at times not only save the life of the patient, but change him. The relationship between the physician and the patient will become more profound in terms of the patient's need to understand the consequences of his disease and treatment, in terms of thoughful and sympathetic advice concerning his choices, and in terms of guaranteeing participation of the patient in the making of decisions. The physician may also be called upon to serve as counsellor to the community on such matters as potential environmental contamination and the design of laws and 1ieaIth measures which could protect against it. The physician of the future must be a competent scientist, a practitioner of medical skills, and an educator and advisor of both his patient and the public at large. Anything short of wise discharge of these responsibilities will represent f ai'1ure. Now to return to the two subjects previously raised. First, how well does our current medical education prepare the student for the future? Historically, medical eduction has been an apprenticeship training period. The intellectual substance of medicine was developed through pragmatic experience on the part of doctors, who transmitted this information to the student by having him join with them to learn. The good student was considered to be the one who best emulated the teacher. This is part of the historical genesis of the view that medicine is an art, not a science. The introduction of science into medicine, which has been particularly rapid in the last two decades, has somewhat changed the orientation of medical education. Students are expected to learn about science and the scientific method and to begin to apply this to work with patients. However, the current teaching of clinical medicine all too often retains attributes of the old apprenticeship. It is commonly based on subjective impressions and experiences of the teacher rather than upon the understanding, even though inadequate, which we now have of disease mechanisms and the effects of treatment. Medical literature is characterized by generalizations and practical conclusions which are not substantiated by fact. We are all familiar with the inadequate proof of the widely disseminated assertions that diets low in fats will reduce the incidence of atherosclerosis or that the use of anticoagulants will reduce recurrent coronary occlusions or cerebral vascular accidents. An example less PHYSICIANS, MEDICAL STUDENTS AND CITIZEN RELATIONSHIPS 187 obviously in this category is our common teaching that pulmonary edema results from left ventricular failuie and is primarily cardiac in origin. Because of this view, our treatment consists in the main, of the use of digitalis and diuretics, though fortunately morphine is usually included. What would be our teaching, and perhaps our treatment, if Gamble had created acute hemorrhagic pulmonary edema by placing a lesion in the hypothalamus before Welch produced the same result by putting a hot iron to the left ventricle? Contradictions are apparent between the practices of the past and the needs of the future in the teaching of s t d e n t s . In the past, the student learned the accumulated experiences and techniques of the teacher. Today he must 3ssimilate large amounts of scientific information gathered in many disciplines. In the past he learned diagnosis and treatment by formulae passed on from the teacher. In the future he will have to know the independent exercise of the scientific method including conduct of an analysis, evaluation of data, and application of conclusions to a given patient in terms of the likelihood of success in diagnosis and therapy. In the past, the student was expected to emulate the teacher. Now he must be taught to be independent, to accept that part of teaching which can be substantiated and to reject and refrain trom using that which cannot. The persistence of the apprenticeship training method in current medical education has a stultifying effect upon the student. By not perceiving the scientific method themselves, many teachers tend to suppress the originality of the student, to restrict his opportunities to probe unsolved problems, and consciously or unconsciously to compel him to think as they do. As with other diciplines which involve analysis followed by action, medicine and science require teaching which gives the student impetus and opportunity to learn independent thought, judgment and action. How long will it be before medical education as a whole recognizes that medicine and science cannot be taught by providing answers for students? The task of the teacher is to pose problems for the student, to demonstrate what is known and what is unknown about these problems, to make clear to the students the limitation of the teacher’s understanding and to challenge and stimulate the students tci go beyond the teacher. In this \yay, goals will be posed and the students propelled toward their realization. Because characteristics of this type do not dominate in medical education today, we are not appropriately preparing the doctor of the future. The increasing intrusion of science into medical education brings with it a second problem which confronts all scientific disciplines, and which is of great relevance for medical teaching. This is the problem of authoritarianism in science. It is created by the increasingly intense study of narrower areas of science. As a result the individual scientist’s knowledge of other fields is frequently reduced, forcing him to rely more and more on the stated views of authorities in other areas. The scientist so afflicted, not knowing the observational basis of the conclusions or prevalent hypotheses in an adjacent field, will be more likely to fit his conclusion into an erroneous framework for generalization or may avoid generalization, being content to amass descrip- 188 HALSTED R. HOLMAN tive information. The result may be either an incorrect general conclusion or merely a collection of isolated bits of information, without identification of natural laws which govern the phenomena under investigation. The issue has been sharply focused by Hubbard, in an article entitled, “Are we retrogressing in Science,” in Science, 8 March; 1963. Stressing that the true authority on natural phenomena is the valid observation or experiment, he states: “It follows that the acceptance of any conclusion, valid or otherwise, hy an individual who is not familiar with the observational data upon which it is based and the logic by which it is derived, is a negation of science and a return to authoritarianism.” Hubbard then develops the thesis that the evolution of science is not one of increasing complexity, but, on the contrary, is a progression from the complex to the simple. Science dervies, out of a welter of seemingly unrelated pieces of information, a few generalizations which reduce wide ranges of phenomena into relationships which are comparatively easy to understand. In our field of biology one recognizes the enormous unifying and clarifying force of the Darwinian theory of evolution. the gene theory of heredity, the germ theory of disease and the concept of homeostasis. One of the harmful aspects of authoritarianism is its contribution to a decline of theory. Narrowness of perspective limits the ability to discern and to use wisely the central theories of other fields. Commoner, writing recently on this matter, stressed the way in which recent developments in nucleic acid biochemistry have been interpreted by some to resolve the age-old conflict concerning the origin of cell division in favor of the hypothesis that there is a self-duplicating seemingly “living” subcellular material. By implication, this material, DNA, contains within itself and transmits all the characteristics of life. Commoner’s view is that a more inclusive knowledge based upon the physicist’s concepts of complementarity, the embryologist’s concept of differentiation and the chemist’s knowledge of the role of protein enzymes in replication of DNA would preclude this generalization as being, at least, premature. Not all of the relevant data have been considered. Commoner’s criticism is not without substance, because some microbiologists have clearly expressed the view that once the genetic code is cracked, problems of biology will be resolved. It is particularly striking that current concepts of the role of DNA in inheritance have become known amongst some scientists as the “central dogma.” What irony-the most modern descendant of the Reformation and Renaissance, the molecular biologist, endowing his recent hypothesis with the term dogma at the precise moment that an antagonist of the Renaissance, the Catholic church, is actively broadening its intellectual horizons and eliminating untenable aspects of its theological beliefs. Such matters are potentially quite relevant to medical teaching. Despite the illuminating biological theories mentioned, there is a poverty of theory in medicine. We have no appropriate concepts to clarify such major processes as the intrinsic rhythmicity of cells (e.g., brain or heart cells), the influence of one organ system upon another (e.g., the role of the nervous system in tissue PHYSICIANS, MEDICAL STUDENTS AND CITIZEN RELATIONSHIPS 159 response to infection or renal effects on blood pressure), or the influence of m e cell upon anothcr (e.g., cell differentiation or cellular hypersensitivity or the effects of breakdown products of a liver cell upon, say, a cell of the lung or the endothelium). We have a tendency to attempt to apply to medical matters whatever biological concepts are current. Those of molecular biology are now fashionable, witness the stream of articles interpreting human biological phenomena in terms of nucleic acid biochemistry. Some of these interpretations will prove correct and they will certainly stimulate important thought. However, concepts developed with unicellular organisms may not be directly applicable to the mammalian cell or to the integrated functions of many organ systems in the mammalian organism. It i y not a matter of minimizing the importance of nucleic acids; it is a matter of avoiding the narrowness 06 horizons and premature generalizations which give the appearance of universality without the substance. We would be wise to imbibe the principles of various biological fields and to develop the discipline of clinical investigation which will permit us to derive laws of human biology directly from observations on human beings. The undesirable consequences of authoritarianism in science lie less in the delay which they cause in the emergence of true knowledge than in the damage they do to the students. The student may become alienated from medicine by lack of originality, flexibility and breadth in its scientific thinking just as readily as he will from a lack of scientific content. If it is true that there is a major shortage of science in medical thinking and teaching, and that the science which is present is afflicted with the problems of parochialism, specialization and authoritarianism, then we who are teachers of medicine have much to do before it can be said that we are appropriately training the doctor of the future. The second subject dealt with relationships between the medical profession and the citizen. I should like to speak first of the citizen’s understanding of medicine and second of the citizen’s role in the provision of medical care. Medicine deals with the most personal aspect of a human being’s existence, his health. No other branch of science possesses so immediate and personal a relationship with the citizen. As science has burgeoned in recent decades, its impact on the citizen has steadily increased. The desirable relationships between science and other elements of society in terms of financing, direction of effort, understanding and ultimate control have not been established. The relationship of scientific medicine to the citizen is no more clear. Perhaps I can illustrate the point best by a brief digression into the general problem of science and society. Sir Charles Snow brought the issue to a head a few years ago by asserting that the scientist, by virtue of his training, is slightly more objective and honest and therefore slightly better equipped than any other person to lead society. This unleashed a storm which has yet to subside. Robert Hutchins countered with the view that his experience as a university president convinced him that professors were somewhat worse than other people, and scientists were some- 190 HALSTED R. HOLMAN what worse than other professors. Such is not the stuff of illuminating debate. However, Hannah Arendt, writing in the October 1%3 issue of The American Scholar on “Man’s conquest of space,” has presented a most succinct statement of the issue. “Has man’s conquest of space increased or diminished his stature? The question raised is addressed to the layman, not the scientist, and it is inspired by the humanist’s concern with man, as distinguished from the physicist’s concern with the reality of the physical world.” Professor Arendt continues: “The answer is not likely to convince the scientist because he has been forced under compulsion of facts and experiments to renounce sense perception and hence common sense by which we coordinate the perception of our five senses into the total awareness of reality.” Dr. Arendt’s fundamental concern is that science, by reducing phenomena to abstractions, has developed a perception of man in the universe which is not understandable in human terms. It thereby becomes antihuman. Dr. Arendt continues: “For the point of the matter is, of course, that modern science-no matter what its origins and original goals-has changed and reconstructed the world we live in so radically that it could be argued that the layman and the humanist, still trusting their common sense and communicating in everyday language, are out of touch with reality, and that their questions and anxieties have become irrelevant.” Quoting Nils Bohr to the effect that “only by renouncing an explanation of life in the ordinary sense do we gain a possibility of taking into account its characteristics,” she continues, “the very integrity of science demands that not only utilitarian considerations but even the reflection upon the stature of man be left in abeyance. The simple fact that physicists split the atom without hesitation the very moment they knew how to do it, although they realized full well the enormous destructive potentialities of their operation, demonstrates that the scientist qua scientist does not even care about the survival of the human race on earth or for that matter about the survival of the planet itself.” These are strong charges, and they are all the more difficult to refute for they in no way challenge the scientist’s motives. These may be absolutely pure and humanistic. The point is that the method by which the scientist works, which is abstraction, is potentially antihuman and may lead him into actions which are antithetical to the interests of the citizen. For one involved in medicine, it is particularly striking to read Dr. Arendt’s article and substitute the phrase “the achievement of biological understanding” for “the conquest of space.” The effect is made even sharper by considering how one would feel to be a layman in the hands of a physician possessed of the power to change one’s mind or one’s reproductive function or one’s physical capabilities. The issue is perhaps sharper for the physician than for any other scientist. I n pure science, the subject is a fragment of nature. In medicine, the subject is one’s fellow man. In abstract terms the difference is meaningless. In social terms the difference is absolute. Unless scientific medicine is made understandable to the patient and the patient participates in the decisions as to how it will be used, scientific medicine may become antihuman. Science, in PHYSICIANS, MEDICAL STUDENTS AND CITIZEN RELATIONSHIPS 191 order to serve humanity, must be understood by human beings and its applications must be subject to their will. Clearly the introduction of scientific medicine will require change in the relationships between the physician and the citizen. The application of scientific medical knowledge to a patient will be one form of the use of specialized knowledge by one citizen for the benefit of another. This will involve an intellectuaI compact considerably broader than discussions at the time of the illness. The citizens will wish to know the powers of the profession, and the ways in which the profession expects to exercise and control these powers. The citizens will probably choose to identify those issues which are purely technical or professional and separate them from those which involve humanistic or social judgment. The latter may well be removed from the jurisdiction of the physician, as has been the case in the decisions concerning who will receive protracted dialysis treatment for chronic renal failure in the city of Seattle. Because of the deep personal character of illness, and the potential biological powers of the physician, the relationship between physician and citizen could become a prototype of the desirable relationships between men in the age of science. To what extent are these matters represented in our curricula or on the agendas of our medical societies? To what extent do they appear in our thoughts as medical teachers and physicians? The second aspect of the relationship between the physician and the citizen relates to the financing and organization of medical education and medical care. More immediate and controversial than the preceding issue, it is also probably more easy of solution. Indeed the lines of solution have already been demonstrated in the debate on Medicare. The public and its representatives are beginning to make decisions about the ways in which medical care shall be financed and organized. We physicians are in a position to say, figuratively, to the citizens: “We can treat effectively many simple disorders and we are beginning to cope well with certain of the major diseases of man. We anticipate in the near future a great increase in our ability to treat most diseases. While we can not stop the processes of aging and death, disease is not a necessary accompaniment of aging. We should be able to control and perhaps prevent much of the chronic illness which our older people experience. However, to do all this will be expensive and in any individual case the cost of medical care may become extremely high. You the citizens must think about ways in which you wish to take advantage of these developments.” Perceiving this, the public will certainly concern itself with many aspects of medical education and medical care. The profession will be unable to avoid doing likewise. Indeed, a compelling case can be made for the view that the public and the profession should work at the problems together. Imagine that you were a member of such a working body. What would be your views? IVould you agree, as a beginning principle, that it is a proper objective of physicians and of society to provide the finest medical care of which man is 192 HALSTED R. HOLMAN capable to all citizens without subjecting any citizen or his family to economic distress? I would hope you would. But if you do, many questions of considerable importance flow from there. What methods would you consider to finance the care of patients? Despite the rapid growth of insurance in the past fifteen years, only one third of medical costs are covered. Unless some means of financing are found to meet swiftly rising costs, large segments of the population are going to remain with mediocre medical care or worse. Will you agree with the insurance principle? If you do, how widely would you extend it? TO what extent would you consider that every citizen must contribute if every citizen is to benefit? Would you accept the view that sound insurance funding involves the insuring of the low risk (i.e., the relatively healthy young) simultaneously with the high risk (i.e., the elderly)? How would you finance the education of doctors? Over the past decade, with modest improvement in the past two years, the quality and quantity of applicants to medical school has diminished strikingly. We are not now attracting into medicine the best young people in our country. Would you wish to give the powers of which we have been speaking to persons who are less than the best available? Will you tolerate a situation in which intelligent and devoted young people cannot obtain a medical education for lack of scholarship funds, or because of their color, or because they are women? How would you solve the problem of guaranteeing maximum efficiency of financial management and maximum quality of medical care? We know that problems exist in the latter area as, for example, a recent incident in which over 18 per cent of obstetrical deliveries were accomplished by Caesarian section until sharp criticism was levelled. The rate then dropped to less than 3 per cent, indicating the real need for this procedure. Will you seek to devise some sort of review boards? Do you believe that the consumer, that is the patient, should have a voice in the planning and management of medical care? If you do, how should this be expressed, and how should it relate to questions of professional judgment? If the time arrives when the medical profession has the power to alter the minds and bodies of patients, how would you recommend that the patients and their families participate in the decisions about whether this awesome power should b e used? Up to now these questions have been left unanswered or only partly answered. As a result there is doubt that the existing forms of medical care are compatible with the best development of medical science and the best distribution of the benefits of this science to the people. I do not believe they are, for they have not resolved current problems, much less given evidence of being able to meet the more demanding requirements of the future. It is likely that a new relationship will emerge between the medical profession and the citizen. In this relationship the physician will retain the responsibility for professional aspects of his work, but will join with the citizen in elaboration of the ways in which that professional knowledge will be provided to the patient and imparted to the student. The relationship of physician to citizen will be a special case of the broader relationship between science and society; and if I may hazard a guess, that broader relationship will be re- PHYSICIANS, MEDICAL STUDENTS AND CITIZEN RELATIONSHIPS 193 dressed to place in the hands of the citizens a stronger rein over those applications of science which influence the well-being of society. This relationship will also contain the seeds of resolution of the apparent conflict between abstract and humanistic thought. Abstract thought, as practiced by scientists, is not inherently anti-human; it is, after all, the highest product of the human mind. It appears anti-human when applied as a seemingly uncontrollable force in social affairs without the consent of the citizen. Abstraction will not be anti-human if the new relationships identified by abstraction are resolved again into common terms. An intellectual cooperation between the scientist and the citizen should provide the vehicle for accomplishing this. It is indeed exciting to contemplate what the mind of man enables him to do. In the field of meldicine for the first time the goals of a scientific medical education and of medical care of high quality available to all are in sight. The methods of achieving them are emerging. Considerable thought on the part of both physicians and citizens will be needed, and probably much cooperative action between them. Such combined effort, not present in the past or today, could provide the key to rapid utilization of scientific advance for the improvement of medical care. I suspect that we could all come to enjoy such an effort. I also suspect that if Dr. Bauer were alive, he would be in the thick of it. Halsted R. Holman, M.D., Prof. of Medicine, Stanford Uniuersity School of Medicine, Palo Alto, Calif.