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Postgrad Med J: first published as 10.1136/pgmj.37.434.755 on 1 December 1961. Downloaded from POSTGRAD. MED. J. (I96I), 37, 755

MEGALOBLASTIC ANAEMIAS OF GASTROINTESTINAL ORIGIN J. P. KNOWLES, M.A., M.B., M.R.C.P. M.R.C. Research Fellow T. A. J. PRANKERD, M.D., M.R.C.P. Medical Unit, University College Hospital Mledical School, London, W.C.I

THERE exist two known anti-megaloblastic sub- described secondary to pancreatic disease (Mollin, stances, B12 and folic acid. Both of these 1959). are absorbed from the small intestine and the body Even less is known about the absorption of folic is dependent on their dietary supply to prevent acid. In the diet much of the folic acid exists in abnormal changes in haemopoiesis. Deficiencies of conjugated form, and this has been shown to be these compounds may arise in a number of ways, less well absorbed than the unconjugated form but one important group arises from abnormalities (Jandl and Lear, I956). Whether this difference is of the small intestine interfering with normal due to preferential absorption of the unconjugated absorptive mechanisms. form or difficulty in deconjugating, or both, is un- known, as is the part played by digestive enzymes. by copyright. Absorption The site of absorption of folic acid is also not The efficient absorption of is known known with certainty. From a study of patients to depend on the formation of a complex with an with Crohn's disease affecting various parts of the unspecified material, intrinsic factor. The mech- small intestine Cox and others (I958) and Doig anism through which absorption is actually pro- and Girdwood (I960) found of folic moted and the problem whether intrinsic factor is acid was most frequent when the disease affected simultaneously absorbed or left in the small bowel the jejunum. Resection of sufficient ileum to result remain obscure, but the site of absorption is well in malabsorption of vitamin B12 does not as a rule delineated and appears to be in the terminal ileum lead to malabsorption of folic acid (Chanarin, (McIntyre, Sachs, Krevans and Conley, 1956; Anderson and Mollin, i958a; Cox and others, Cox, Meynell, Cooke and Gaddie, 1958; Booth 1958; Doig and Girdwood, I960). However, http://pmj.bmj.com/ and Mollin, 1959). Thus loss of intrinsic factor, there is no conclusive evidence that the absorption as in pernicious , after total of folic acid is confined to the proximal small and sometimes after partial gastrectomy (Badenoch, intestine. Evans, Richards and Witts, 1955; Maclean, I957) The bacterial flora of the gut play a rather or loss of the terminal ileum, either by surgical mysterious role in the absorption of vitamin B12 resection or disease, inevitably leads to mal- and folic acid. A normal flora which is probably absorption of vitamin B12. confined to the terminal of the ileum is only part on October 1, 2021 by guest. Protected It appears that calcium ions may be necessary not likely to influence normal absorption, but in for efficient absorption of the vitamin B,2-intrinsic many diseases of the small intestine bacteria may factor complex (Grasbeck, Kantero and Siurala, flourish where they do not normally exist. Since 1959) and it is possible that the removal of calcium some bacteria show an avid utilization of vitamin ions by fatty acids may partly impair vitamin B12 B12 (Burkholder, I952; Doig and Girdwood, absorption in steatorrhcea, but little is known yet 1960), it is possible that a profuse growth would about their role. If calcium ions were an important compete with the body for the available vitamin factor, then malabsorption of vitamin B12 in pan- leading to a deficiency. Certainly the response of creatic steatorrhcea would be expected to occur, and some of the disorders to be considered to broad- this has been shown (Halstead, Lewis, Hvolbolt, spectrum antibiotics lends support to such a Gasseter and Swenseid, 1956; Frost, Goldwein theory. Most bacteria actually synthesize vitamin and Kaufman, 1957; McIntyre and others, 1956). B12 and folic acid, but since these organisms are However, megaloblastic anemia has never been mainly confined to the large bowel, their synthetic Postgrad Med J: first published as 10.1136/pgmj.37.434.755 on 1 December 1961. Downloaded from 756 POSTGRADUATE MEDICAL JOURNAL December 1961 products are not available for absorption. This may lead to malabsorption (Lambert, Prankerd topic has been well reviewed by French (1961). and Smellie, I96I). Results of Malabsorption Detection of Deficiency and Measurement of Malabsorption of vitamin B12 and folic acid Absorption inevitably leads to depletion of the body stores of The measurement of absorption of vitamin B12 these . The sequence of changes in the and folic acid can only be done effectively by the development of is better use of radioactive isotopes incorporated into the known than in that of folic acid, because pure vitamin. With such material physiological quanti- vitamin B12 deficiency occurs after total gastrec- ties of these substances can be incorporated into tomy and in pernicious anaemia. The speed of the diet. Measurements of absorption after giving onset of symptoms and signs will obviously depend loadifig doses impose abnormal concentration- on the size of the body store when absorption gradients throughout the absorbing surface of the begins to fail. For some reason the sequence of small intestine and cannot be regarded as sensitive changes is quicker in pernicious anaemia in relapse tests for defective absorption, though they are than after total gastrectomy and Mollin (1959) undoubtedly a guide to intestinal function. suggests that this may be due to the fact that Radioactive vitamin B12 and folic acid are now patients with pernicious anaemia are not in- easily obtainable. The former, labelled with 58Co, frequently incompletely repleted with vitamin B12. can be estimated by readily available apparatus. Paulson.and Harvey (I954) followed up 80 patients Folic acid labelled with tritium requires a liquid after total gastrectomy. Six of them survived long scintillation counter (Anderson, Belcher, Chanarin enough to develop megaloblastic anaemia two to and Mollin, I960). seven years (average 4.25 years) after the operation. It should be borne in mind that the demonstra- It can be estimated that the stores of tion of impaired absorption does not necessarily body a of vitamin B12 amount to about i mg., which on imply body deficiency that compound. For values for of about I to 2 this assessment other tests are available. In the

daily requirement (g by copyright. would account for the latent interval of about two case of vitamin B12, estimation of the serum level to three years before the onset of anaemia. is a reliable means of assessment of body stores In course of time vitamin B12 deficiency leads (Spray and Witts, 1958), but in the case of folic to megaloblastic anaemia often associated with acid serum measurements have not yet proved leucopeenia and even thrombocytopcenia. Sub- wholly successful (Herbert, Wasserman, Frank, acute combined degeneration may complicate this Pasher and Baker, 1959; Baker, Herbert, Frank, of its Pasher, Hutner, Wasserman and Sobotka, 1959; deficiency regardless cause. Baker, Herbert, Frank, Pasher, Sobotka and Pure dietary folic acid deficiency in adults was Wasserman, 1960; Niewig, Faber, de Vries, reported for the first time (Knowles, Prankerd and Stenfert Kroese, 1954); and as a result various Westall, I96I) in patients fed, perforce, on artificial indirect procedures have been introduced to assess diets. The stores of folic acid became sufficiently body stores of folic acid. The urinary excretion of http://pmj.bmj.com/ depleted to give abnormal histidine tests after folic acid after a test dose might be expected to be four to six weeks. At this time there were no proportional to the degree of tissue saturation, but, hamatological or changes. After io whilst this is roughly true, there is sufficient over- months one of the patients was still not anaemic lap between normals and abnormals to make the (Hb. = I5 g./Ioo ml.). These observations are in test unsatisfactory (Cox, Meynell and Cooke, keeping with those of Najjar and Holt (I943) and I961). Chanarin, Anderson and Mollin (I958b) Najjar and Barrett (I945), who fed human volun- showed that the rate of clearance from the plasma on October 1, 2021 by guest. Protected teers on diets containing 13 to I7 ,ig. per day of an intravenous dose of folic acid was propor- of folic acid. After I8 months there were no tional to the degree of folic acid deficiency, but it hamatological abnormalities. Stores of' folic acid- also seems to be proportional to the degree of like' substances have been estimated at about marrow activity and therefore not specific; the 5 to io mg. (Girdwood, 1959) with a daily require- results of this test before and after treatment with ment of 5 to Io ,zg. (Knowles and others, 1961). small doses of folic acid which have not been Folic acid deficiency eventually leads to identical reported would be of interest. haematological changes as vitamin B12 deficiency, Bakerman, Silverman and Daft (1951) noted a but neurological sequele do not occur. glutamic acid precursor in the urine of folic acid- The role of vitamin B12 and folic acid deficiency deficient rats which was later shown to be formi- in preserving the integrity of the mucous mem- minoglutamic acid (FIGLU) (Borek and Waelsch, branes ofthe gastrointestinal tract is much debated. 1953; Seegmiller, Silverman, Tabor and Mehler, Evidence is accumulating that deficiency of either 1954). FIGLU is an intermediate in histidine Postgrad Med J: first published as 10.1136/pgmj.37.434.755 on 1 December 1961. Downloaded from December 1961 KNOWLES and PRANKERD: Megaloblastic Ancemias of Gastrointestinal Origin 757 metabolism and by giving a suitable dose of histi- Absorption of folic acid has been reported to be dine it has been shown that the excretion of reduced in over 90% of patients (Chanarin and FIGLU can be increased (Tabor, Silverman, others, 1958a; Cox and others, 1958; Doig and Mehler, Daft and Bauer, I953), thus providing a Girdwood, I960). In all these studies large doses suitable laboratory test for folic acid deficiency of folic acid were used (3 to 5 mg.), doses which are (Luhby, Cooperman and Teller, I959a and b; 15 to 25 times greater than the total average daily Knowles, Prankerd and Westall, I960). intake; it may well be that these tests are really Using this test we have found the following measuring the absorptive capacity of the gut rather results in I05 cases of steatorrhcea: than the physiological absorption of folic acid. Such tests are, however, useful measures of in- Abnormal Normal testinal function. Anderson and others (1960) used test teft more doses of labelled Idiopathic steatorrhoea . 46 2 physiological folic acid and Postgastrectomy steatorrhcea 6 8 found malabsorption in nine out of 13 patients as Regional ileitis .... 9 8 measured by faecal excretion. Pancreatic steatorrhoea .. o 6 Folic acid deficiency, when assessed by the Jejunal .. 2 o an Secondary to liver disease .. I I excretion of excess of FIGLU after a histidine Reticulosis of the small in- load, appears to be at least as common as mal- testine ...... I I absorption when measured by the folic acid load Scleroderma affecting upper tests I961). jejunum ...... (Knowles, Diagnosis uncertain ... 2 Tropical Sprue _66 39 This is a most interesting condition with many o05 unexplained features. The geographical dis- tribution of tropical sprue suggests that it may be Diseases of the Small Intestine related to dietary habits. Thus it is common in Idiopathic Steatorrhoea, Cuba and Puerto but rare in Rica, neighbouring by copyright. Idiopathic steatorrhcea probably comprises a Jamaica. It occurs in Hong Kong, but is un- group of diseases for which there is no satisfactory common in Singapore. It is common in India, but name. Many alternatives (adult coeliac disease, almost absent from Africa and the Pacific (Gardner, gluten-induced enteropathy, primary malabsorp- I958). French (I955, i96i) has suggested that tion syndrome) have been suggested, but none has this may be related to the consumption of un- met with universal approval. Gluten-sensitivity saturated fatty acids in the sprue areas. Tropical seems to be a common cause in adults and even sprue can occur within a few weeks of arrival in an more so in children. endemic area and in patients in an apparently Megaloblastic anaemia is much less common in excellent state of nutrition, suggesting, in the early children than in adults. Sheldon (1958) gives an stages at least, that malnutrition is not an im- incidence of 9%. It is known to be much com- portant factor. have been Jejunal biopsy changes http://pmj.bmj.com/ moner in adults, but exact figures are scarce. noted within Io days of the onset of diarrhoea Cooke, Peeney and Hawkins (I953) found macro- (Butterworth, C. E., personal communication to cytic anaemia in two-thirds of Ioo patients; 49 Gardner, 1958). of the Ioo had bone marrow examinations and 17 Treatment of the established disease may be had definite megaloblastic changes, II were en- affected by removal from the affected area, by tirely normal and the other 2I were intermediate. folic acid or by antibiotics. The prognosis is The anemia may be due to deficiency of iron, usually excellent, but an occasional case reaches

folic acid or vitamin B,1. A dimorphic blood an apparently irreversible stage. Folic acid de- on October 1, 2021 by guest. Protected picture with evidence of and hypo- ficiency has not been clearly demonstrated, but chromia is very suggestive of malabsorption. most cases respona to folic acid alone, suggesting Serum vitamin B,2 levels are low and absorption that deficiency of this vitamin, however deter- of labelled vitamin B2 is reduced below normal in mined, is important in keeping the disease active. approximately half the patients which have been Not all such patients are anaemic. There is often studied, though figures vary from one group of no evidence of vitamin B1 deficiency in the early worker to another (Mollin, Booth and Baker, 1957; stages of the disease (Frazer, 1960; Gardner, Spray and Witts, 1958; Meynell, Cooke, Cox and 1958), but it is not uncommon in the later stages Gaddie, I957; Halstead, Lewis and Gasseter, 1956; (Gardner, 1958). Frost and others, I957; Oxenhorn, Estren, In a proportion of patients it is necessary to Wasserman and Aldersberg, 1958; Turnbull, give antibiotics before a full remission is obtained 1954; Callender and Evans, 1955; Doig and Gird- (French, 196I; French, Gaddie and Smith, I956). wood, I960). Antibiotics alone may also induce a remission Postgrad Med J: first published as 10.1136/pgmj.37.434.755 on 1 December 1961. Downloaded from 758 POSTGRADUATE MEDICAL JOURNAL December 1961 (Keele and Bound, 1946; Foy and Kordi, 1954). of the stomach remnant, but occasionally a blind The incidence of megaloblastic anaemia varies in loop is the cause (Naish and Capper, I953). reports from different parts of the world, but it would seem to be inevitable if the disease is not Infiltrative Diseases of the Small Intestine treated or it does not undergo spontaneous In regional ileitis and jejunitis megaloblastic remission. anaemia is occasionally observed. The mechanism operates through the formation of blind loops or Pancreatic Steatorrhoea fistulae, or the wall of the small intestine may be so As previously mentioned, megaloblastic anamia diseased that absorption is impeded. In the first has not been recorded in this type of steatorrhoea, group cure may sometimes be effected by anti- although absorption of vitamin B12 is impaired. biotics and in the latter group corticosteroids will Absorption of folic acid is normal (Cox and occasionally bring amelioration (Cooke, I958). others, 1958) and there does not appear to be a Tuberculosis (Davidson, 1950) and reticuloses deficiency in the body stores of folic acid (Knowles, (Girdwood, I960) of the small intestine are rare I96I). causes of megaloblastic anaemia. Amyloidosis of the small intestine and Whipple's of the Liver and Megaloblastic Ancmia disease not infrequently lead to steatorrhcea, but, Although steatorrhcea may occur as a complica- so far as we are aware, megaloblastic anaemia has tion of cirrhosis of the liver, megaloblastic anemia, not been reported. Hendrix, Black-Schaffer, when it occurs, is probably not due to this cause. Withers and Handler (1950), in a general review, Nutritional deficiency or hepatic failure would state that is uncommon in seem the most likely causes. In any case, it is rare. Whipple's disease and report one of their four cases as having a bone marrow showing 'slight Intestinal Strictures, Resections, Fistulee, Blind arrest of and tissues'. Loops and Jejunal Diverticula erythro- myelo-blastic Two mechanisms in the of Fish Worm operate production Tape by copyright. megaloblastic anaemia. First, the terminal ileum Diphyllobothrium latum, the fish tape worm, (the site of vitamin B12 absorption) may be by- which affects particularly the population of Fin- passed by or removed by resection. land and Japan, has been directly demonstrated Secondly, strictures or jejunal diverticule may to have a high affinity for vitamin B,1. In vivo it give rise to blind loops of intestine. Here micro- competes with intrinsic factor for the vitamin, but organisms not normally found in the small in- if intrinsic factor and vitamin B12 are mixed prior testine multiply and interfere with absorption. to ingestion there is no interference with absorp- One of the ways they may do this is by actually tion (Brante and Ernberg, I958). Infestation with competing with the intestine for vitamin B12 this worm is common in Finland (9 to I2% of the (Doig and Girdwood, 1960; Badenoch, Bedford population, depending on the area) (von Bons- and Evans, have not been shown a small of I955). Organisms dorff, 1948), though only percentage http://pmj.bmj.com/ to compete for folic acid in vitro. Nevertheless, infected persons develop significant anaemia (I in folic acid deficiency does occasionally arise, though 113, i in 659) (Totterman, it is much less common than vitamin B12 de- 1944). ficiency. Girdwood (I960) reports a possible case Diagnosis and we have seen two cases where there was an The peripheral blood pictures in all cases of abnormal excretion of FIGLU. One of these megaloblastic anaemia are often indistinguishable, patients also had a low vitamin B12 level (80 showing macrocytosis and considerable deformity Ezyg./ml.) and vera, but the other of the red cells. All cases of vitamin B12 deficiency on October 1, 2021 by guest. Protected patient had no other cause for her megaloblastic can show subacute combined degeneration of the anamia. Girdwood (I960) suggests that folic acid cord. A most important clue to the occurrence of deficiency may arise from direct bacterial irritation malabsorption in theaetiology is the presence of of the gut wall. Folic acid absorption tests using coincidental evidence of iron deficiency. This is high dosage of folic acid are usually normal in absent in untreated pernicious anaemia and the these patients (Doig and Girdwood, 1960). Im- rarer causes of megaloblastosis; it manifests itself paired absorption of vitamin B12 has been demon- in the peripheral blood by the appearance of hypo- strated by Halstead, Lewis, Hvolbolt, Gasseter chromic red cells. Other evidence of iron de- and Swendseid (1956), Frost and others (i957), ficiency may be obtained from serum iron levels. Mollin and others (1957) and Oxenhorn and others as demonstrated by the augmented (1958), and low serum B12 levels by Spray and histamine test seems synonymous with total gastric Witts (1958). Megaloblastic anaemia after partial atrophy, and if pernicious anaemia is not present gastrectomy is usually due to subsequent atrophy it may be expected to develop (Card and Circus, Postgrad Med J: first published as 10.1136/pgmj.37.434.755 on 1 December 1961. Downloaded from December 1961 KNOWLES and PRANKERD: Megaloblastic Ancemias of Gastrointestinal Origin 759 1958). However, the presence of free acid excludes intestinal biopsy is usual in post-gastrectomy pernicious anemia except in young people (Lam- steatorrhcea, pancreatic steatorrhoea, cirrhosis and bert and others, I96I). Evidence of coincident folic in steatorrhcea associated with blind loops and acid deficiency is also present in the more severe jejunal diverticulosis. cases of pernicious anaemia (Knowles and Prankerd, I96I). Treatment Ultimate diagnosis therefore rests on a combina- Symptomatic treatment of megaloblastic anaemia tion of the histological and radiological demonstra- of any cause may be effected by giving folic acid tion of an abnormality in the gastrointestinal tract, or vitamin on the together with evidence of malabsorption. Barium B12, depending deficiency. studies showing flocculation patterns are im- When megaloblastic anaemia is due to intestinal portant, as is the demonstration of malabsorption causes more specific therapy is usually desirable, by estimation of daily fat and urinary calcium directed at the cause. Thus nearly all children excretion. The latter may rarely be abnormal in with caeliac disease and most adults with idiopathic pernicious anaemia (Lambert and others, I96I). steatorrhcea will respond to withdrawal of gluten Final differentiation from pernicious anaemia may from the diet. The excretion of FIGLU will be achieved by studies with 58Co-labelled vitamin cease in two to four months after starting on a B,2 in which the restoration of normal absorption gluten-free diet, suggesting complete replacement is demonstrated by administering vitamin B12 with of the body stores of folic acid after this time intrinsic factor. The amount of the latter used is (Knowles, 1961). important, since excessive amounts may increase The treatment of tropical sprue has already been vitamin B12 absorption in idiopathic steatorrhcea discussed. (Callender and Evans, I955). Antibiotics will usually induce a haematological Finally, mucosal biopsy from the jejunum and remission in the blind-loop syndrome, but it is stomach is particularly useful in diagnosis as interesting to note that neomycin, the most power- specific changes can often be detected in different ful intestinal antibiotic of all, does not do this by copyright. disorders. Pernicious anaemia patients show com- (Halstead, Lewis and Gasseter, 1956). Neomycin plete gastric atrophy. Characteristic changes are is not absorbed, so possibly does not reach the found in the small intestine in idiopathic steator- blind loops in sufficient concentration to be effec- rhcea, tropical sprue, regional ileitis and Whipple's tive. Surgical procedures will be required when disease. The finding of a normal, or nearly normal, correction of some anatomical defect is necessary. REFERENCES ANDERSON, B., BELCHER, E. H., CHANARIN, I., and MOLLIN, D. L. (I960): The Urinary and Faecal Excretion of Radio- activity After Oral Doses of 3H Folic Acid, Brit. J. Hcemat., 6, 439. BADENOCH, J., BEDFORD, P. D., and EVANS, J. R. (1955): Massive Diverticulosis of the Small Intestine with Steatorrhcea and Megaloblastic Anemia, Quart. J. Med., 24, 321. , EVANS, J. R., RICHARDS, W. C. D., and WITTS, L. J. (1955): Megaloblastic Anaemia following Partial Gastrectomy http://pmj.bmj.com/ and Gastroenterostomy, Brit. J. H-emat., I, 339. BAKER, H., HERBERT, V., FRANK, O., PASHER, I., HUTNER, S. H., WASSERMAN, L. R., and SOBOTKA, H. (1959): A Micro- biologic Method for Detecting Folic Acid Deficiency in Man, Clin. Chem., 5, 275. -, -, --, ,SOBOTKA, H., and WASSERMAN, L. R. (1960): The Measurement of Folic Acid Activity in Serum. A Diagnostic Aid in the Differentiation of the Megaloblastic Anaemias, Blood, 15, 228. BAKERMAN, H., SILVERMAN, M., and DAFT, F. S. ( 95 I): Influences of Succinyl Sulfathiazole and Folic Acid on Glutamic Acid Excretion, J. biol. Chem., I88, II7. BOOTH, C. C., and MOLLIN, D. L. (1959): The Site of Absorption of Vitamin B12 in Man, Lancet, i, i8.

BOREK, B. A., and WAELSCH, H. (1953): The Enzymatic Degradation of Histidine, J. biol. Chem., 205, 459. on October 1, 2021 by guest. Protected BRANTE, G., and ERNBERG, T. (1958): The Mechanism of Pernicious Tape Worm Anaemia Studied with 60Cobalt- labelled Vitamin Bi2, Acta med. scand., x60, 91. BURKHOLDER, P. R. (1952): Microbiological Studies in Materials which Potentiate Oral Vitamin B12 Therapy in Addisonian Anaemia, Arch. Biochem., 39, 322. CALLENDER, S. T., and EVANS, J. R. (I955): Observations on the Relationship of Intrinsic Factor to the Absorption of Labelled Vitamin B12 from the Intestine, Clin. Sci., 4, 387. CARD, W. I., and CIRCUs, W. (1958): Anacidity, in 'Moder Trends in Gastro-enterology', chap. II, p. 177. Ed. Avery Jones, F. London: Butterworth. CHANARIN, I., ANDERSON, B. B., and MOLLIN, D. L. (1958a): The Absorption of Folic Acid, Brit. J. Hcemat., 4, 156. , , (I958b): The Clearance from the Plasma of Folic Acid Intravenously in Normal Subjects and Patients with Pernicious Anaemia, Ibid., 4, 435. COOKE, W. T. (1958): Anemia and the Alimentary Tract, Lancet, ii, 258. , PEENEY, A. L. P., and HAWKINS, C. F. (I953): Symptoms, Signs and Diagnostic Features of Idiopathic Steator- rhea, Quart. J. Med., 22, 59. Cox, E. V., MEYNELL, M. J., and COOKE, W. T. (1961): Folic Acid Deficiency, Postgrad. med. J., 37, 252. -, , and GADDIE, R. (I958): The Folic Acid Excretion Test in the Steatorrhcea Syndrome, Gastroenterology, 35, 390. Postgrad Med J: first published as 10.1136/pgmj.37.434.755 on 1 December 1961. Downloaded from 760 POSTGRADUATE MEDICAL JOURNAL December 1961 DAVIDSON, L. S. P. (I953): Megaloblastic Anaemia and Subacute Combined Degeneration from Tuberculous Disease of the Small Intestine, Gastroenterologia (Basel), 79, 342. DOIG, A., and GIRDWOOD, R. H. (I960): The Absorption of Labelled and Folic Acid in Intestinal Malabsorption, Quart. J. Med., 29, 333. FoY, H., and KORDI, H. (1954): The Haematuric Action of Penicillin in Megaloblastic Anaemia and its Relationship to Vitamin B11 Metabolism and the Intestinal Flora, Trans. roy. Soc. trop. Med. Hyg., 48, I7. FRAZER, A. C. (1960): Pathogenetic Concepts of the Malabsorption Syndrome, Gastroenterology, 38, 389. FRENCH, J. M. (1955): The IEtiology and Mechanism of Steatorrhcea, Postgrad. med. J., 31, 299. -(96I): Problems Raised by the Treatment of Steatorrhoea with Anti-bacterial Drugs, Ibid., 37, 259. , GADDIE, R., and SMITH, N. M. (1956): Tropical Sprue, Quart. J. Med., 25, 333. FROST, J. W. GOLDWEIN, M. I., and KAUFMAN, B. D. (1957): Studies of B,, Co60 Absorption in Malabsorption Syn- drome: Results Before and During Specific Therapy, Ann. intern. Med., 47, 293. GARDNER, F. H. (I958): Tropical Sprue, New Engl. J. Med., 258, 791 and 835. GIRDWOOD, R. H. (I959): The Role of Folic Acid in the Blood Disorders, Brit. med. Bull., 15, 13. (1960): Folic Acid, its Analogs and Antagonists, in 'Advances in Clinical Chemistry', 3, 235. New York: Academic Press Inc. GRABECK, R., KANTERO, I., and SIURALA, M. (1959): Influence of Calcium Ions on Vitamin B12 Absorption in Steatorrhcea and Pernicious Anaemia, Lancet, i, 234. HALSTEAD, J. A., LEWIS, P. M., HVOLBOLT, E. E., GASSETER, M., and SWENDSEID, M. E. (1956): An Evaluation of the Faecal Recovery Method for Determining Intestinal Absorption of Cobalt Vitamin B,1, J. Lab. clin. Med., 48, 92. 6°-labelled , --, and GASSETER, M. (1956): Absorption of Vitamin B1, in the Syndrome of Megaloblastic Anaemia Associated with Intestinal Stricture or Anastomosis, Amer. J. Med., 20, 42. HENDRIX, J. P., BLACK-SCHAFFER, B., WITHERS, R. W., and HANDLER, P. (1950): Whipple's Intestinal Lipodystrophy. Report of four cases and discussion of possible pathogenic factors, A.M.A. Arch. intern. Med., 85, 91. HERBERT, V., WASSERMAN, L. R., FRANK, O., PASHER, I., and BAKER, H. (I959): Value of Fasting Serum 'Folic Acid Levels, Fed. Proc., i8, 970. JANDL, J. H., and LEAR, A. A. (1956): The Metabolism of Folic Acid in Cirrhosis, Ann. intern. Med., 45, I027. KEELE, J., and BOUND, J. P. (I946): Sprue in India: A Clinical Survey of 6o0 Cases, Brit. med. 5., i, 77. KNOWLES, J. P. (196I): Excretion of Formiminoglutamic Acid in Steatorrhcea, Gut (in press). - , and PRANKERD, T. A. J. (i96i): Abnormal Folic Acid Metabolism in Pernicious Anaemia, Clin. Sci. (in press). -, , and WESTALL, R. G. ( 96 ): Folic Acid in Requirements Man, J. Physiol., 157, 24P. by copyright. , -- (1960): Simplified Method for Detecting Formiminoglutamic Acid in Urine as a Test for Folic Acid Deficiency, Lancet, ii, 347. LAMBERT, H. P., PRANKERD, T. A. J., and SMELLIE, J. M. (I96I): Pernicious Anaemia in Childhood, Quart. J. Med., 30, 7 I LUHBY, A. L., COOPERMAN, J. M., and TELLER, D. N. 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