clinical approach". - Europe PMC

nuity); is deregistering the total account; or is 65 years of age or over. In addition, -the transfer restriction does not apply to any benefits accumulated by a member in the common stock fund or shortterm deposit fund portions of the account. Before 1974 the variation in interest rates in the insured annuity fund was not extensive, and the National Life Assurance Company found it possible to accommodate most requests for lump-sum transfers to other RRSPs. However, since Jan. 1, 1975 the changes in interest rates have been more dramatic, and the National Life Assurance Company, with the agreement of MD Management Ltd., formalized the transfer procedure outlined here. In times of marked increases in interest rates even this alternative does not fully protect the position of members continuing in the plan; currently a charge of 1% of the amount transferred applies when current interest rates exceed the average rate earned in the transferred account. As mentioned earlier, the 5-year transfer agreement is a relaxation of the basic contract provision and is provided only on a current basis by the National Life Assurance Company. A report is available from MD Management Ltd. to any member wishing further details concerning the lump-sum transfer restriction. R.P. BANNERMAN

&F*I"L NW

-

-~ U

lEE -

ffm *** ww mu 5 invuU

&

-

EDMONTON ALBERTA CANADA, SEPTEMBER 22, 23, 24,1980

SEPTEMBER 22 and 23 "IMMUNOLOGY: CLINICAL APPROACH".

"DELIVERY OF HEALTH CARE: NEXT DECADE"

Speakers are ... Sir Gustav Nossal (Australia) (U.S.A.) Dr. Fritz Bach Dr. D.K. Peters (England) Dr. Jack Pepys (England)

Specific topics include ... Medical Education / Medical Manpower (Tuesday) Medical Research / Medical Economics (Wednesday) Also included will be evening public forums.

Vice president, administration MD Management Ltd. Ottawa, Ont.

Serum ferritin concentration and bone marrow iron stores To the editor: We have read the interesting works of different Canadian groups about the value of measuring the serum ferritin concentration in the diagnosis of iron deficiency.' In these series the patients were not previously selected, and the authors refer to the diagnosis of the cases in which the serum ferritin concentration was normal or high and reticular iron in the bone marrow was diminished or absent. Our experience has been that in 25 of 47 (53%) unselected patients

SEPTEMBER 23 and 24

A scientific presentation and related workshops on

SOCIAL PROGRAM features a Provincial Banquet and a Civic Luncheon PLUS a tour of the Canadian Rockies following the Symposium. A warm Alberta welcome awaits delegates in downtown Edmonton.

V-1

. *a-mW '146

I'.b4EGEco

ai

For information on registration, contact:

International Medical Symposium Alberta Medical Association Suite 304, 9901 - 108 Street Edmonton, Alberta Canada T6K 1 G8 (403) 423-2295

ALBERTA MEDICAL ASSOCIATION * COLLEGE OF PHYSICIANS AND SURGEONS OF ALBERTA EDMONTON ACADEMYOF MEDICINE * UNIVERSITY OF ALBERTA * UNIVERSITY OF CALGARY

CMA JOURNAL/JUNE 21, 1980/VOL. 122 1355

with iron deficiency the serum fer- References ritin concentration was not reliable ALI MAM, LUXTON AW, WALKER for making the diagnosis. These re- 1. WHC: Serum ferritin concentration sults agree with those of McGinnis and bone marrow iron stores: a prosand colleagues,5 who found this to pective study. Cant Med Assoc J 118: 945, 1978 be so in 49 of 90 (54%) cases. Ali, E, BAIGET M: Ferritina Luxton and Walker' and Mazza 2. GIMFERRER serica. I: Nuestra experiencia preand colleagues4 found a lower perliminar. Biol Clin Hematol 1: 75, centage of test failures (29% and 1979 16% respectively). Of our 25 pa- 3. GIMFERRER E, AYATS R, PUJOL N, et al: Ferritina serica. II. Correlatients 5 had hemolytic anemia, 5 ciones de la ferritinemia y otros had myelomas, 4 had lymphomas, parametros perifericos con el hierro 4 had neoplastic disease, 2 had a reticulohistiocitario medular. Ibid, p hemopathy (1 of whom had idio263 pathic thrombocytopenic purpura) 4. MAZZA J, BARR RM, MCDONALD JWD, et al: Usefulness of the serum and 5 had other disorders. ferritin concentration in the detection Reviewing our results and those of iron deficiency in a general hosof the other studies',4-5 we found pital. Cani Med Assoc J 119: 884, that of the 98 patients in whom 1978 measurements of the serum ferritin 5. MCGINNIS PL, PATEL AR, RAO KRP, et al: Serum ferritin concentraconcentration failed to diagnose and bone marrow iron stores (C). tion iron deficiency 33 had neoplasias Can Med Assoc J 120: 1204, 1979 (26 of which were malignant hemopathies), 14 had hemolytic dis- Chlorine: effect on thiamin ease, 14 had hepatopathy and 5 concentration had chronic renal insufficiency. These disorders represented 53% To the editor: In many northern Canadian Indian reserves Javex or of the total number of failures. We therefore agree with McGin- javelle is added to the home water nis and colleagues5 that the serum supply, which is used for drinking ferritin concentration does not and cooking, as a disinfectant. The show the good correlation desired raw water comes from lakes, rivers, with the reticular iron content of wells, rain or snow. The chlorine the bone marrow, the classic clin- is added to the water at irregular ical reference parameter of body intervals and in varied amounts by iron status. Whereas a low serum either adults or children. The water ferritin concentration is highly spec- often tastes strongly of chlorine.1 ific for iron deficiency, as has been Recently Yagi and Itokawa' confirmed by all the authors," a showed that residual chlorine can normal or high concentration could "cleave" thiamin in proportion to be found in 16% to 54% of pa- the rise in temperature, pH and tients with iron deficiency. concentration of the residual chlorThus, it can be confirmed that in ine. Rice cooked in chlorinated spite of the technical difficulties in water was shown to have a greatly interpreting and evaluating the re- decreased concentration of thiamin. sults of Prussian blue staining of Concern has been expressed the bone marrow, especially in hy- about the possible low intake of perplastic, infiltrative or tumoural thiamin by Canadian Indians in diseases, the test retains its value northwestern Ontario and northin clinical diagnosis. On the other western Quebec owing to their hand, we need to improve our dietary choices as well as to antiknowledge and especially our meth- thiamin factors in their diets.3 ods of detecting serum apoferritin, Sources of thiamin in the diets of ferritin and the respective isofer- these Indians include enriched ritins, and to measure each of them bread and flour, pasta, cereals, correctly to obtain all the informa- baked beans, potatoes, potato chips, tion derivable from these proteins. meats (including animal organs), E. GIMFERRER, MD fish and evaporated milk. The antiR. AYATS, MD thiamin factors identified include K - N. PUJOL-MOIX, MD tannic acid in tea, heat-stable and M. BAIGET, PH D Hospital de la Santa Cruz y San Pablo heat-labile factors in fresh-water Barcelona, Spain fish, the high carbohydrate intake, 1356 CMA JOURNAL/JUNE 21, 1980/VOL. 122

alcohol3 and baking powder (J.N. Thompson: personal communication, 1979). In view of the data presented by Yagi and Itokawa' it is important to ascertain whether the addition of Javex or javelle to drinking and cooking water by northern Indians will affect the thiamin levels of cooked foods such as pasta, potatoes, cereals and meats. CAROL SPINDELL FARKAS, B SC, M ED Department of man-environment studies University of Waterloo Waterloo, Ont.

References 1. FARKAS CS: Survey of northern Canadian Indian dietary patterns and food intake. Nutr Plann 2: 37, 1979 2. YAGI N, ITOKAWA Y: Cleavage of thiamine by chlorine in tap water. J Nutr Sci Vitaminol 25: 281, 1979 3. FARKAS CS: Potential for and implications of thiamine deficiency in northern Canadian Indian populations affected by mercury contamination. Ecol Food Nutr 8: 11, 1979

Canadian national breast cancer screening study To the editor: Some details of the Canadian national breast cancer screening study were given in the Jan. 26th issue of the Journal (122: 243, 1980). While I understand that this is a large-scale randomized controlled trial, I do not understand why the American data were apparently not studied in more detail before the Canadian study was designed. The study by the Health Insurance Plan of Greater New York showed a reduction in breast cancer mortality only for women who were more than 50 years of age at the time of screening.' It is true that the risk of radiation-induced breast cancer from mammography is based on inference,2 but the ad hoc working groups of the National Cancer Institute have concluded that there is no safe dose of radiation and that six cases of breast cancer will be induced per rad of tissue dose per million women screened after a 10-year period.3 Thus, 18 to 30 new breast cancers will be induced and no lives saved by the screening of 100 000 women less than 50 years old. There are probably five situa-