Howard L. Alt

Acid Hydrolysis of Erythropoietin.

Summary Purified erythropoietin has been subjected to mild acid hydrolysis. This mucoprotein thus has been further characterized and shown to lose erythropoietic activity upon hydrolytic removal of neuraminic acid.

Purification of Erythropoietin by Ion-Exchange Chromatography

Summary A method for purification of erythropoietin from the filtrate of acidified, boiled plasma prepared from phenylhydrazine anemic rabbits utilizing DEAE-cellulose ionexchange columns has been described. The active erythropoietic factor thus prepared has been partially characterized and shown to be a low molecular weight, acidic glycoprotein.

Protective Effect of Hypoxia against Irradiation Injury of the Rat Bone Marrow and Spleen.

Summary 1. Rats irradiated in a hypoxic atmosphere show a slightly higher cellularity and much greater rate of DNA synthesis in the bone marrow and spleen after 96 hours than rats irradiated at ground level. 2. Thirty hours of intermittent hypoxia preceding irradiation at low oxygen tensions does not give additional protection. 3. A striking parallelism exists in the cellular reactions in the bone marrow and spleen following irradiation, both at normal atmospheric pressures and at low oxygen pressure. 4. Irradiation of animals at low oxygen pressures appears to reduce the biological effectiveness of 800 r on the bone marrow to 600 r.

Erythropoietic Activity of Tissue Homogenates.

Summary Homogenates of rat liver, kidney, brain, spleen and muscle prepared in modified Tyrodes solution and injected into the rat are capable of stimulating erythropoiesis as measured by Fe59 incorporation into red cells and reticulocyte counts. The activity of the homogenates does not appear to be a nonspecific effect. Certain points of similarity are noted between the homogenates and plasma erythropoietin.

Nucleic acid metabolism of bone marrow and spleen. I. Normal values and effect of sodium pentobarbital.

Summary (1) Normal values are presented for the desoxyribose nucleic acid phosphorus and ribose nucleic acid phosphorus as well as the rate of uptake of P32 by the DNA and RNA in the bone marrow and spleen of adult rats. (2) Anesthetic doses of sodium pentobarbital were found to produce a significant decrease in the relative rate of formation of DNA in the bone marrow and spleen during a period of 5 1/2 hours. (3) The significance of these observations is discussed.

Manometric Studies on the Bio-oxidation of Histamine

Best and McHenry 1 reported observations on a histamine-inactivating substance or system which they denote as histaminase. They state that oxygen is consumed during this reaction but have postponed a detailed manometric study until obtaining a more concentrated histaminase preparation. We have found that a kidney powder, prepared according to their directions, when added to histamine gave sufficient gas changes to study the histamine-histaminase reaction from the standpoint of oxygen uptake. The experiments were performed in the Bar croft-Warburg apparatus, with air in the gas space, phosphate buffer in the conical vessel, KOH in the well, and a measured amount of histamine in the side bulb. Since attempts at materially purifying the enzyme were unsuccessful, 200 mg. dry kidney powder from the dog were used in the phosphate solution as a source of histaminase. When the system was at a constant temperature, 37.5°C, the histamine was tipped into the vessel and manometric readings were made at regular intervals until the oxidation ran to completion. Parallel experiments were always made without histamine because the powder alone had a small oxygen uptake. (Ca 25% of that with histamine.) This was subtracted in every case from the values found with the addition of the base. The rate of oxidation early in the experiments was constant. Ten minute observations of the histamine oxidation plus the gas change due to kidney powder averaged about 6 to 8 cmm. of oxygen. When the oxygen uptake had ceased, the histamine was inactivated as shown by its failure to contract guinea pig intestine in vitro. On the other hand, when the oxygen uptake was not complete, the substrate was capable of contracting smooth muscle. This was observed in several experiments.

Effect of Intermittent Exposure to Simulated High Altitude in Erythropoiesis in the Guinea Pig.

Conclusions Guinea pigs exposed to simulated altitudes of 23,000 and 30,000 feet 6 hours a day and 6 days per week became fully acclimatized after 200 hours, as shown by maximal increase in the values for red corpuscles, hemoglobin, and hematocrit. Reticulocytosis and enlargement of the spleen were also demonstrated.

Effect of Depriving Newborn of Placental Blood upon Early Postnatal Blood Picture

Within the last few years, the collection of postpartum placental blood for “blood banks” has been strongly advocated not only in Russia 1 but also in Canada 2 and in this country. 3 4 5 It has been pointed out that this is an inexhaustible and “lucrative” source of blood, satisfactory for transfusion purposes, and that its collection has no deleterious effect upon the mother. Possible effects upon the child have been disregarded because it has already become a rather common obstetrical practice to clamp the umbilical cord promptly at birth in spite of the fact that most of the placental blood normally drains into the body of the infant within a few minutes when the umbilical cord is not clamped immediately after delivery. 6 When the cord is clamped immediately, the infant is deprived of an alarming proportion of its total blood volume and usable iron at the very beginning of extra-uterine life. We have obtained proof that this blood-letting at birth affects the blood picture of the newborn significantly. The practice should be strongly condemned. We have determined the amount of hemoglobin and number of red blood corpuscles in blood taken from the mother on the day of birth, in cord blood at birth, in blood from the newborn (heel) 15 to 75 minutes after birth, and from the infant at one, 3 to 4, and 6 to 7 days after birth in 2 series of patients. In one series of 25, the umbilical cord was clamped within 30 seconds after delivery; in another series of 29, clamping was delayed until pulsations had ceased and the placenta had separated. Hemoglobin was determined in grams percent with a calibrated Hellige-Sahli instrument. Red blood corpuscle counts were made with a Spencer hemo-cytometer (N.B.S.).

Experimental goat's milk anemia.

Many reports have appeared, especially in the German literature, concerning a pernicious anemia-like syndrome occurring in infants fed with goats milk. 1 György 2 has recently reported such cases which responded to liver but not to iron therapy. Rominger, Bomskov, et al., 3 have reported the occurrence of a pernicious anemia picture in young white rats fed on goats milk. The erythrocyte counts decreased rapidly without corresponding decreases in the hemoglobin. This anemia did not respond to iron therapy but responded to liver extracts effective in pernicious anemia. Von Haam and Beard 4 also have observed a hyperchromic character of the anemia in rats during the first weeks of feeding with goats milk. György 2 states that he was unsuccessful in producing a hyperchromic anemia in rats by this method. The experiments reported in this paper show no evidence of a specific type of anemia in white rats fed on goats milk. Three litters of 6 albino rats each, of the Wistar strain, were weaned at 23 days and put into individual glass cages. Their weights averaged 40-45 gm. They were fed exclusively on goats milk∗ which was collected directly into clean glass containers at the dairy and delivered to the laboratory every other day. Erythrocyte counts were performed with Bureau of Standards equipment and the hemoglobins with the Newcomer apparatus standardized by the oxygen capacity technique. Erythrocyte counting pipettes and micro-colorimeter cups were used in the hemoglobin determinations. Reticulocyte counts were performed by the method of Cunningham. 6 Cover slips containing brilliant Cresyl blue and Hood were allowed to be in apposition several minutes before making the smears in order to insure complete staining of the reticulocytes. This series of 18 rats received a goats milk diet for a period of 65 days.

Exposure of guinea pigs to intermittent high oxygen tension and its failure to depress erythropoiesis.

Summary Guinea pigs were intermittently exposed to 80-100% oxygen at atmospheric pressure for 57 days, and to 60-70% oxygen at 2 atmospheres pressure for 20 days. The periods of exposure covered 6 hours a day 6 days a week. There was no significant diminution in the erythrocyte counts and hemoglobin values in any of these animals.