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Terminal deoxynucleotidyl transferase activity, immunologic membrane markers, and cytochemical reactivity were examined in blasts of 80 adults with acute leukemia. The study was interinstitutional and prospective so that some assessment could be made of the usefulness and practicality of these tests in the classification of adult acute leukemias. Initial classification as to the type of acute leukemia was based primarily on cytochemistry and only secondarily on the morphology of the abnormal cells. Terminal transferase was uniformly elevated in eight of eight patients with null and T cell lymphoblastic leukemia and two of two patients with null cell lymphoma leukemia, whereas it was elevated in only 3 of 27 specimens defined cytochemically as acute myeloblastic leukemia. Terminal transferase activities were low in 24 of 27 patients with acute myelomonocytic, acute monocytic, and lymphoma leukemia of B or T cell type. Blasts from 17 of 80 patients did not show distinctive patterns of cytochemical staining, and these patients were classified as having acute undifferentiated leukemia. When these 17 coded specimens were submitted to a panel of four hematologists and classified by each as lymphoid or nonlymphoid based on morphology, there was disagreement in 9 of the 17. In this situation the usefulness of additional methods of cellular classification such as terminal transferase and membrane markers became manifest.

R-Type serum vitamin B12-binding proteins (cobalophilins) are a heterogenous population of glycoproteins. The reason for this appears to be due to variation in the carbohydrate moieties of the macromolecules. To support this contention we have used different sugar-specific lectin-sepharose affinity columns as a means for separating cobalophilins. Concanavalin A-Sepharose can resolve serum vitamin B12-binding activity into three distinct fractions. The first two are cobalophilins and the third is transcobalamin II. The major cobalophilin fraction does not interact with concanavalin A-Sepharose, but is bound completely by both wheat germ and castor bean II lectins. Elution from these columns can be accomplished by addition of the appropriate competitive sugar to the buffer. Castor Bean I Lectin-Sepharose resolves the major concanavalin A-Sepharose cobalophilin fraction into two distinct fractions—one which does not interact with this lectin and the other which is eluted when N-acetylgalactosamine is added to the buffer. Furthermore, the distribution of exogenous-bound (57Co) cyancobalamin between these two fractions is different when comparing certain myeloproliferative diseases in which serum cobalophilins are usually elevated. It is suggested that use of lectin—Sepharose resins may be a more definitive method for defining cobalophilin variants than is presently available.

Protein-mediated B12 uptake by L1210 lymphoblasts was shown to be calcium dependent and enhanced by TCII but not by TCI in vitro. Subcellular fractionation resulted in the majority of B12 localized in the soluble phase with significant amounts in the mitochondria. All vitamin B12 found in the soluble phase was bound to a protein similar in molecular weight to TCII. This protein was capable of delivering B12 to fresh L1210 cells.

Protein-mediated B12uptake by L1210 lymphoblasts was shown to be calcium dependent and enhanced by TCII but not by TCI in vitro. Subcellular fractionation resulted in the majority of B12localized in the soluble phase with significant amounts in the mitochondria. All vitamin B12found in the soluble phase was bound to a protein similar in molecular weight to TCII. This protein was capable of delivering B12to fresh L1210 cells.

1. A survey of the incidence of abnormal hemoglobins in different racial groups distributed over the island of Puerto Rico was performed. The relation of the rate of destruction of red cells to the presence of abnormal hemoglobin patterns in the affected population was also studied. 2. The abnormal hemoglobins were classified by the difference in paper electrophoretic mobility. Fetal hemoglobin was measured by its resistance to alkaline denaturation. The red cell life span was determined by measuring the survival of erythrocytes labelled with radioactive sodium chromate. 3. A total of 2,089 inhabitants were studied. There were 1,487 white subjects and 602 Negroes. Forty-two individuals were found to harbor abnormal hemoglobins. All but one were Negroes or Negroid of African descent, and their relative numbers agreed closely with the geographical distribution of ethnic groups in the island. Abnormal hemoglobins were found in 2.01 per cent of the entire series of 2,089 persons, but in those considered Negroes or Negroids the incidence of abnormal hemoglobins was 6.8 per cent. Of the 42 persons showing abnormal hemoglobins, thirty-four or 81 per cent, had hemoglobin S; only two of these had sickle cell anemia. The incidence of the sickle cell trait among the Puerto Rican Negro population was 5.2 per cent; and the incidence of hemoglobin S disease among those harboring the trait was 5.9 per cent. Eight, or 19 per cent of the abnormal cases had hemoglobin C; only one of these had hemoglobin C disease with clinical hemolytic anemia. The incidence of the hemoglobin C trait among the Puerto Rican Negro population is 1.3 per cent; and the incidence of hemoglobin C disease among those harboring the trait may reach 12.5 per cent. 4. All 42 cases harboring abnormal hemoglobins showed very small quantities of fetal or alkali-resistant hemoglobin ranging from 0.45 per cent to 3.25 per cent, averaging 1.12 per cent. 5. The "apparent" half-life of the red blood cells was found to be 10 days in sickle cell anemia, 7 days in SC disease, 20.6 days in cases of hemoglobin SA, 18.5 days in one case of hemoglobin C disease and 21.5 days in 2 cases of the combination CA. The normal "apparent" half-life in our laboratory is 24.5 days.