Franklin C. Bing

Availability of iron in wheat.

Elvehjem, Hart, and Sherman 1 have reported that the inorganic iron content of wheat is approximately 47% of the total iron content. Their biological studies indicated that this figure also represents the available iron content. On the contrary Rose, Vahlteich, and MacLeod 2 observed that wheat is an excellent source of iron for hemoglobin formation. In order to determine whether there is any great variation in the form of iron in different varieties of wheat, 11 samples representing both hard spring wheat and soft winter wheat were analyzed for total and inorganic iron. A modification of the technic of Elvehjem, Hart, and Sherman, 1 which employs a longer extraction period, was used to determine the inorganic iron, whereas the total iron was determined on ashed samples by the thioglycolic acid method. 3 The total iron of the 11 samples ranged from 2.90 mg. to 4.87 mg. of iron per 100 gm. of wheat. The inorganic iron showed about the same amount of variation, the range being from 2.46 mg. to 4.04 mg. of iron per 100 gm. of wheat. The percentage of inorganic iron with respect to the total iron varied from 73% to 88%, the average being 81%. This figure agrees fairly well with the value suggested by Shackleton and McCance. 4 Two of the samples of wheat were also used for a biological assay. Albino rats were made anemic by employing an exclusive milk diet. As soon as values below 4.0 gm. of hemoglobin per 100 cc. of blood were attained, the experimental diets were started. Three groups of experimental animals received 0.25 mg. of iron per day. One group of 5 animals received 0.25 mg. of iron per day furnished by FeCl3; a second group of 6 animals received Trumbull wheat (soft winter wheat) in quantities to supply the same amount of iron per day; and the third group of 6 animals received Nabob wheat (soft winter wheat) in quantities to supply 0.25 mg. of iron per day.

MICROSCOPIC-ANALYTICAL METHODS IN FOOD AND DRUG CONTROL

What you will find as you delve more intensely into this book is an application of these problems to a patient-centered curriculum in an associate degree program, a three-year basic diploma program, and a bachelor of science program. It would be worthy of consideration if those public health nursing educators and service personnel responsible for effective services to families and communities would attempt to examine the value of a similar approach. There is also an inclusive list of references of which any serious reader of this book will make use. MADELYN N. HALL

Effect of Heat on Vitamin G Potency of Desiccated Yeast

In the course of their investigations on the nutritive requirements of the chick Elvehjem, Kline, Keenan and Hart 1 found that about half of the vitamin G potency of desiccated yeast was destroyed by heating at 100°C. for 6 days. With the hope of securing evidence of the supposed duality of vitamin G, as postulated by Sure 2 and others, we have studied the effect of heat on both the growth-promoting and dermatitis-preventing activities of dried yeast. After preliminary desiccation the yeast was heated in an electric oven at either 105 °C. or 150°C. for various lengths of time. The resulting products were fed, at a level of 1.5 gm. per mouse per week, to 3-weeks-old mice maintained on an otherwise G-deficient diet. The basal ration was prepared by mixing 200 gm. of vitamin-free casein, 265 gm. of cornstarch, 205 gm. of sucrose, 200 gm. of lard and 40 gm. of McCollums salt mixture. Each animal received apart from the basal diet 2 drops of a tested cod liver oil and an ample amount of a vitamin B preparation. The latter was made from wheat germ by extraction with 93% alcohol, distillation of the extract in vacuo, and separation of the potent aqueous residue from an inert oil. The vitamin G activity of the yeast preparations, as measured by the growth response of the mice, is recorded in Fig. 1. No decrease in the vitamin G potency of yeast heated at 105° was observed. Further experiments with mice fed varying amounts of dried yeast, heated at 105° for 2 weeks, would be necessary to reveal whether a slight inactivation occurs. From the limited data available, however, it may be concluded that the destruction of vitamin G under these conditions is certainly not extensive. Moreover, Block and Farquhar, 3 who used the rat as their experimental animal, have recently reported that they observed no decrease in the growth-promoting activity of yeast that had been heated at 100° for 2 or even 4 weeks. Our data show further that the growth-promoting activity of yeast is slowly lost as a result of prolonged heating at 150°. There is a little vitamin G remaining even after one week of such treatment, but the vitamin is entirely destroyed in 2 weeks. Each of the 4 mice receiving the yeast that had been heated at 150° for 2 weeks developed typical skin lesions, as described by Bing and Mendel, 4 and all were dead in 7 weeks. At this time the mice in the other groups were still alive and their skins were in good condition. It appeared that the mice which had received sufficient vitamin to permit some growth had likewise received enough of the anti-dermatitis factor to meet their requirements, and the experiment was therefore discontinued.

Magnitude of Urinary Iron Excretion in Healthy Men

Henriques and Roland 1 have found that the daily excretion of iron in the urine of both normal and pathological cases is very small, amounting to only 0.08 to 0.32 mg. These values are much lower than those reported by earlier workers. Lintzel, 2 however, has claimed that not more than 0.02 mg. of iron per liter can be found in normal urine. Likewise, other investigators 3 have found the urine of patients suffering from various diseases to be practically iron-free. Because of its bearing on problems relating to the metabolism of iron we have investigated anew the question of the magnitude of the urinary iron excretion. The urine was obtained in clean bottles from male subjects who were pursuing their usual routine in the laboratory. In brief, the analytical procedure consisted of the following steps: A measured volume, usually 500 cc, of the fresh 24-hour urine specimen was evaporated to dryness in a silica dish, and then incinerated in an electric furnace at about 500° C. for 8 hours. The ash was dissolved in dilute HC1, brought to a volume of 50 cc, and aliquot portions were removed for the determination of iron by the thio-glycolic acid method. 4 The analytical technic was subjected to repeated tests and found to be adequate. All reagents were shown to be free from iron. Small quantities of iron added to urine were quantitatively recovered, proving that iron was not lost in the manipulations. Finally, a solution of pure substances was prepared in imitation of the main constituents of urine and this solution was evaporated, ashed, and analyzed for iron. None could be detected, proving that the iron found in the analyses was not due to contamination.

Vitamin C and the Common Cold

The many admirers of Linus Pauling will wish that he had not written this book. Here are found, not the guarded statements of a philosopher or scientist seeking truth, but the clear, incisive sentences of an advertiser with something to sell. Unfortunately, many laymen are going to believe the ideas that the author is selling—that ascorbic acid is a completely harmless chemical which will prevent or mollify infectious diseases such as the common cold, if taken in doses of from 1 to 10 gm daily throughout life, and possibly extend that lifetime from two to six years. Actually, when used as recommended by Professor Pauling, neither the safety of all dosage forms, nor the efficacy of ascorbic acid in any dosage form, has been proved. Pauling hopes that there will be a thorough, large-scale study on vitamin C and the common cold. Because he has already convinced himself that vitamin

A Method for the Estimation of Serum Iron.

The drawing of blood under conditions aiming to avoid hemolysis, as described by Fowweather, 1 has yielded in our hands serum that invariably gives a positive benzidine test and shows the absorption bands of oxyhemoglobin if a sufficient thickness of solution is examined. The present method for the estimation of the non-hemoglobin iron of blood serum consists of 2 steps, the analysis of the serum for total iron and for hemoglobin iron. The total iron is determined by ashing 2 cc. of serum with 2 cc. of concentrated sulfuric acid, with the aid of 30% H2O2. The ashed sample is diluted to 15 cc. with water, enough potassium permanganate is added to give a permanent pink color, 5 cc. of ethyl acetate are layered over the solution and, finally, 5 cc. of 20% ammonium thiocyanate solution are added and the mixture is shaken. The color in the ethyl acetate layer is compared in a micro-colorimeter with a standard containing 0.005 mg. of iron similarly treated. The traces of iron in the reagents are determined by blank analyses. The quantitative benzidine method 2 is employed for the determination of the hemoglobin, but allowance must be made for the effect of serum proteins on the reaction. Proteins and certain salts cause a diminution in the color produced in the benzidine acetate-hemoglobin-H2O2 system. The method may be summarized briefly. To 2 cc. of the benzidine reagent 0.5 cc. of blood serum and 0.5 cc. of water are added, followed by 1 cc. of 0.6% H2O2 solution. In another test tube the same procedure is carried out, except that 0.5 cc. of the standard solution of blood, containing 0.05 mg. of hemoglobin per cc., is used in place of 0.5 cc. of water.

Metabolism of Iron and Copper in Anemic Rats

Rats were made anemic by restriction to a diet of cows milk. This milk was obtained directly in glass bottles from Guernsey cows and contained an average of 0.14 mg. of copper per liter. One group of 5 anemic rats was sacrificed. The stomachs and intestines were removed, and the carcasses were analyzed for iron and copper. Another group of 5 rats received daily supplements of 0.5 mg. of iron as pure ferric chloride. A third group of 6 rats received daily intraperitoneal injections of 0.5 mg. of iron, and a fourth group received 0.5 mg. of iron and 0.025 mg. of copper as copper sulfate each day per os. Hemoglobin determinations were made at intervals on blood samples secured from the tails. In 17 days the animals receiving iron by mouth had increased their hemoglobin from an average concentration of 4.15 gm. to 7.23 gm. per 100 cc. of blood. The rats receiving iron intraperitoneally increased their hemoglobin from 4.03 gm. to 12.92 gm. in the same time, and the rats receiving iron and copper orally increased their hemoglobin from 3.90 gm. to 13.40 gm. per 100 cc. of blood. These data confirm conclusions reached in previous work from this laboratory, 1 namely, that supplements of iron bring about some hemoglobin production in anemic rats and that intraperitoneal injections of iron result in hemoglobin production at about the same rate and to the same extent as oral administrations of both iron and copper. The average values for the analyses of the carcasses of the rats for iron and copper are recorded in Table I. These figures show that the hemoglobin production in the rats receiving injections of iron is associated with an increase in the copper content of the body over that of control rats sacrificed at the beginning of the experiment. It has been calculated that the average retention of copper in this group of rats was 73% of the total intake in the form of the copper of the milk, while in the group receiving iron orally it was 17% and, in the group receiving both iron and copper, only 12% of the total intake during the experimental period.

Efficacy of Intraperitoneal Injection of Iron in the Nutritional Anemia of Rats

Hart and his collaborators 1 reported that anemic rats did not recover when pure iron salts were administered unless small amounts of copper were also given. These observations have been confirmed in several laboratories, but Myers and his collaborators 2 have always been able to secure some response with iron alone. The present series of experiments continues work previously reported designed to gain some insight into the reasons for the conflicting results. It is well-known that many factors may affect intestinal absorption of iron. We have therefore studied the effect of parenterally administered solutions of ferric chloride. Rats were made anemic by restriction to a diet of certified milk, using both the technic described by Waddell et al 3 and the method of Elvejhem and Kemmerer. 4 No difference in the response of the anemic animals to treatment was observed with either procedure. The animals, which were severely anemic, were injected intraperitoneally with ferric chloride solutions prepared from electrolytic iron. The stock solution of iron was diluted with warm, sterile saline solution (prepared from copper-free sodium chloride) and injected immediately after dilution, using a tuberculin syringe and chromium plated needles. The dilutions were so arranged that the amount of fluid injected into each animal was always 0.50 cc. regardless of the dosage. The acidity of the original stock solution was also adjusted so that the reaction of the material injected was between pH 2.0 and pH 2.5. To avoid excessive irritation the animals received injections only on alternate days. At regular weekly intervals hemoglobin determinations and red cell counts were made upon blood obtained by clipping the tail. The rats consumed 20 to 30 cc. of milk daily at the beginning of the experiment, increased the intake with the instigation of iron therapy, and drank as much as 90 to 100 cc. per day after attaining a weight of about 125 gm.