role of ceruloplasmin in iron metabolism. J Clin Invest

15. Ragan HA, Nacht S, Lee GR, Bishop CR, Cartwright GE. Effect of ceruloplasmin on plasma iron in copper- deficient swine. Am J Physiol 1969;217:1320-3

16. Osaki S, Johnson DA, Frieden E. The mobilization of iron from the perfused mammalian liver by a serum copper enzyme, ferroxidase I. J Biol Chem 1971 ;246: 301 8-23

17. Carver FJ, Farb DL, Frieden E. The effect of albumin, ceruloplasmin, and other serum constituents on Fe(ll) oxidation. Biol Trace Element Res 1982;4:1- 19

18. Williams DM, Christensen DD, Lee GR, Cartwright GE. Serum azide-resistant ferroxidase activity. Biochim Biophys Acta 1974;350:129-34

19. Evans PJ, Bomford A, Halliwell B. Non-caeruloplas- min copper and ferroxidase activity in mammalian se- rum. Ferroxidase activity and phenanthroline-detect- able copper in human serum in Wilson’s disease. Free Radical Res Commun 1989;7:55-62

20. Percival SS. Iron metabolism is modified by the cop- per status of a human erythroleukemic (K562) cell line. Proc SOC Exp Biol Med 1992;200:522-7

21. Lastra 0, Chueca A, Lachia M, Gorge L. Root uptake and partition of copper, iron, manganese, and zinc in Pinus radiata seedlings grown under different copper supplies. J Plant Physiol 1988;132:16-22

1970;49:2408-17 22. Dancis A, Yuan DS, Haile D, et al. Molecular char-

acterization of a copper transport protein in s. cerevi- siae: An unexpected role for copper in iron transport. Cell 1994;76:393-402

23. Askwith C, Eide D, Van Ho A, et al. The FET3gene of S. cerevisiae encodes a multicopper oxidase re- quired for ferrous iron uptake. Cell 1994;76:403-10

24. Odermatt A, Suger H, Krapt R, Solioz M. Primary structure of two P-type ATPases involved in copper homeostasis in Enterococcus hirae. J Biol Chem 1 993;268: 1 2775-9

25. Merchant S, Bogorad L. Regulation by copper of the expression of plastocyanin and cytochrome c552 in Chlamydomonas reinhardtii. Mol Cell Biol 1986;6:

26. Merchant S, Bogorad L. Rapid degradation of apo- plastocyanin in Cu(ll)-deficient cells of Chylamydo- monas reinhardtii. J Biol Chem 1986;261: 15850-3

27. Merchant S, Hill K, Howe G. Dynamic interplay be- tween two copper-titrating components in the tran- scriptional regulation of cyt c6. EMBO J 1991;lO:

28. Nakamura M, Yamagishi M, Yoshizaki F, Sugimura Y. The syntheses of plastocyanin and cytochrome 0553 are regulated by copper at the pre-translational level in green alga, Pediastrum boryanum. J Bio- chem 1992;111:219-24

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Professional Roles of Dietitians: Do Dietitians and Physicians Agree?

In some quarters, dietitians and physicians do not agree on a role for dietetic practitioners. Dietitians seem to be more highly regarded, and their coun- sel is sought and advice heeded when both health professionals work on developing collegial relationships. Education matters: a course in nu- trition for physicians-to-be and more depth in the sciences for dietetic students are major factors in establishing partnerships in patient care.

The first half of 1994 proved to be a productive, yet disparate period for the continuing saga of the perceived value of dietitians. Two interesting but very different points of view are expressed first by a physician’ and then by a professional society of dietitians? These papers were preceded earlier in the year by the publication of a study designed to measure physicians’ responses to treatment recom-

This review was prepared by Marion Mason, Ph.D., R.D., Ruby Winslow Linn Professor of Nutrition at Sim- mons College, 300 The Fenway, Boston, MA 02115, USA.

mendations generated by dietitian^.^ As a corollary, the concept that one outcome of nutrition education in medical schools is a professional appreciation of dietitians is also receiving some attenti0n.4.~

In his commentary representing a physician’s outlook, McLaren’ draws a distinction between nu- trition and dietetics, nutrition being a “physiologi- cal process” and dietetics “an endeavor that has goals that are social.” Dietetics and medicine are both science (and some art); nutrition on its own is not a true discipline while dietetics is, since it has a clear concept of its identity and goals. The Com- mittee on Opportunities in the Nutrition and Food Sciences6 recently refused to jump into the fray, saying only that nutrition is a discipline or a field of study, thereby avoiding debate about the defining hallmarks of the science of nutrition.

McLaren, identified as being affiliated with a British medical school, further argues that “dietetics is generally poorly regarded,” and that “dietitians are underutilized by the medical profession.” Since this is so, physicians should be trained to be “clin- ical dietetic physicians” or “community dietetic physicians,” practicing in clinical, morbidity-ori-

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ented sites or practicing health promotion in the larger community. Could it be that British dietitians are “underutilized” because there are so few of them (52 dietitians per million population in the UK vs. 196 Registered Dietitians [RDs] per million in the US in 1992)?’

Dietitians, of course, would not agree that their profession is poorly regarded. In fact, the recent po- sition paper of the American Dietetic Association2 argues that “physicians view their registered dieti- tian colleagues as credible sources of nutrition in- formation” and reviews the supporting data.

In the first of the cited reports, Gaare and col- leaguesX used a survey instrument to measure both dietitians’ and physicians’ attitudes about dietitians’ clinical roles. The authors found that “physicians clearly believe they are the primary decision makers for the nutrition care of their patients.” This was certainly not the view of the dietitians, who saw themselves as the primary decision makers more than half the time. In fact, the difference between the MD responses and the RD responses to the que- ry, “Who should be the responsible person?,” was statistically significant in each of five specific clin- ical circumstances related to nutrition support. Such studies are by their very nature limited in the final- ity of their results; for example, while 54% of the sampled dietitians responded, only 36% of the phy- sicians did so.

Interestingly, in a side-bar to this paper, Gaare et a18 remarked that as medical science becomes more complex, dietitians need to increase their knowledge of basic physiologic processes. This view is supported by the Committee on Opportu- nities in the Nutrition and Food Sciences? which suggests that an undergraduate curriculum designed to meet the immediate, short-term needs of entry- level dietetic practitioners and employers is too vo- cational in focus. Such a curriculum excludes a full exploration of the basic sciences that are so neces- sary for a working knowledge of nutrition. In ad- dition, a more flexible curriculum “improves the research base for the practice of dietetics.”

A group of California physicians were surveyed in the winter of 1988 by Rosen and co-workers: The respondents (30% of those contacted) were asked their opinions about the educational back- ground and professional activities of dietitians. Mostly male physicians (85%) participated; over half were between the ages of 41 and 60 years, with a third being 31-40 years old. Slightly over half of the respondents “viewed dietitians as contributing members of the health care team involved at the decision-making level.” An interesting and signifi- cant finding was a negative correlation between physicians’ years in practice and their belief that RDs should have more educational background in

the sciences (as reflected by statements about inter- pretation of laboratory values and specific knowl- edge). The authors note that their observation may reflect an increased awareness (or perhaps knowl- edge?) of nutrition by recent medical school grad- uates.

This was exactly the point made by Levine and colleagues,5 who randomly surveyed 30,000 physi- cians, of whom 11% (3400) responded. Although subjects 45 years of age or older were more apt to assess a patient’s nutritional status, younger physi- cians were more likely to have taken a course in nutrition in medical school. In addition to the age factor, other significant findings correlating to pos- itive attitudes about nutrition included experiences in changing one’s own diet, using nutrition-specific resources (including dietitians), graduating from a foreign medical school, and affiliation with a uni- versity. The authors found, however, that fewer than 40% of physicians usually or always practiced 50 previously identified nutrition behaviors.

An anecdotal note by the authors5 described a “new” program for medical students that asked them to consider their own diets. Positive outcomes in terms of student behavior were observed. More than 35 years ago, medical students and house of- ficers at The Ohio State University Hospitals par- ticipated in a similar program that was organized by the dietitians in a graduate program in preventive medicine in the medical school. During a specific rotation, lunch was served once a week; one week the meal was sodium-restricted, one week caloric- restricted, and so on. The outcome was always a remarkable decline in the number of physician-gen- erated orders for the restriction of the week. Young9 describes a similar program for medical students in a third-year medical clerkship rotation.

Skipper and her colleagues3 tackled the issue of measuring physicians’ perceptions of dietetic prac- titioners’ roles in a very different manner; they were actually able to achieve objective measures. In this study, dietitians’ recommendations about nutrition care were recorded on review forms for each of five consecutive medical record notes that they had made in records of hospitalized patients. Seventy- two hours later, the chief clinical dietitian reviewed the orders written by the physicians and compared those with the RDs’ recommendations. Results of the work of 98 dietitians in 35 hospitals in the Phil- adelphia area were generated from the analyses of the data using standard statistical techniques.

Slightly more than 850 recommendations were written by the dietitians; of these, 42% were imple- mented by the physicians, most (36%) within 24 hours.3 When dietitians made recommendations in response to physicians’ requests for consultation, the implementation rate rose to 50%. The authors

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note that, “as physicians only see patients by re- quest, they may be insensitive to unsolicited rec- ommendations from others.” According to Skipper and co-workers,3 implementation seemed to be highest when the two professionals conferred before the recommendations were written in the medical record by the dietitian (65% implementation rate, p < 0.0001). They lament, however, “that discussion of recommendations . . . is a powerful but inade- quately used tool.”

Interactions between medical students, physi- cians, and dietitians should be encouraged in patient care rounds and conferences to enhance communications among the various health profes- sionals.I0 As Young9 so aptly put it, “the art of learning to practice medicine in an environment with many players” is a major concern in medical education. This is no less true for the practice of dietetics.

1. McLaren DS. Nutrition in medical schools: a case of mistaken identity. Am J Clin Nutr 1994;59:960-3

2. Position of the American Dietetic Association. Nutri- tion-an essential component of medical education. J Am Diet Assoc 1994;94:555-7

3. Skipper A, Young M, Rotman N, Nag1 H. Physicians’ implementation of dietitians’ recommendations: a

study of the effectiveness of dietitians. J Am Diet As- SOC 1994;94:45-9

4. Rosen 0, Downes MJ, Sucher KP, Shifflett B. Phy- sicians’ perceptions of the role of clinical dietitians are changing. J Am Diet Assoc 1991;91:1074-7

5. Levine BS, Wigren MM, Chapman DS, et al. A na- tional survey of attitudes and practices of primary- care physicians relating to nutrition: strategies of en- hancing the use of clinical nutrition in medical practice. Am J Clin Nutr 1993;57:115-9

6. Committee on Opportunities in the Nutrition and Food Sciences. In: Thomas PR, Earl R, eds. Oppor- tunities in the nutrition and food sciences. Research challenges and the next generation of investigators. Washington: National Academy Press, 1994

7. Parks SC, Bajus B. President‘s page: challenging the future-an evolving global perspective for the future. J Am Diet Assoc 1994;94:782-4

8. Gaare J, Maillet JO, King D, Gilbride J. Perceptions of clinical decision making by dietitians and physi- cians. J Am Diet Assoc 1990;90:54-8

9. Young EA. National Dairy Council Award for Excel- lence in MedicaVDental Nutrition Education Lecture, 1992: perspective on nutrition in medical education. Am J Clin Nutr 1992;56:745-51

10. Kusher RF, Tharp FK, Edwards J, Weinsier RL, Brooks CM. Implementing nutrition information into the medical curriculum: a user’s guide. Am J Clin Nutr 1990;52:401-3

Identification of the Triggers of Celiac Sprue

Three theoretically antigenic synthetic peptide plasia of crypts, and infiltration of inflammatory subunits of a-gliadin were evaluated in vivo in cells. four patients with celiac disease. A sequence of The pathogenesis of celiac sprue remains an ac- a-gliadin (amino acids 31-49) was toxic in all pa- tive area of investigation. Gluten is the water-insol- fienfs, suggesting that this sequence is one of the uble (alcohol-soluble) protein moiety of cereal triggers of the immune system in celiac sprue. grains which is associated with sprue. The protein

components of gluten which have toxic potential are

Celiac sprue is a disease of the small intestine that produces malabsorption and improves upon remov- al of gluten from the diet. Patients with celiac sprue can have a wide variety of disease manifestations, from simple iron or folate deficiency, to full-blown malabsorption with steatorrhea, weight loss, fatigue, and severe anemia. In sprue, the small intestine may appear grossly normal on endoscopic examination but microscopically will characteristically show a “flat appearance” (absent or stunted villi), hyper-

termed prolamins, as they are high in proline and amine residues. Prolamins are found in the gliadins of wheat and corresponding proteins contained in barley, rice, and oats.

Analysis of the intestinal response to gluten has implicated cell-mediated immunity with T lympho- cyte activation as the major process through which damage to the small intestine occurs.’ In addition, celiac disease is closely associated with a human leukocyte antigen (HLA) class I1 DQ d p hetero- dimer (DQw2), which restricts CD4 cells in the small bowel mucosa. There is a remarkable asso- ciation between celiac sprue and certain class I1 ma- jor histocompatibility complex antigens, as the dis- ease has been associated with HLA-DR3 Or HLA-DQw2 in all populations studied. The identi- fication of the exact epitope(s) of the gliadin protein

This review was prepared by John R. Saltzman, M.D. and Bernard D. Clifford, M.D. at the ~ i ~ i ~ i ~ ~ of Digestive Diseases and Nutrition, University of Mas- sachusetts Medical Center, Worcester, MA 01 655, USA.

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