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A B S T R A C T In eight patients with sickle cell anemia, weekly extracorporeal carbamylation of about 20% of the circulating red cell mass was carried out for 2 yr or longer. At each visit, a mean of 1.3±0.2 mol of cyanate were incorporated per mole of hemoglobin in the carbamylated erythrocytes. Within 3 mo, a stable level of about 35-50%' of the circulating erythrocytes was carbamylated. This quantity and degree of hemoglobin carbamylation produced a decrease in mean whole blood Pw0 from 33 to 26 mm Hg. During the first 3 mo of carbamylation, the mean hemoglobin increased from 6.4 to 9.1 g/100 ml, while mean absolute reticulocytes decreased by 58% and circulating irreversibly sickled erythrocytes decreased by 65%. The mean red cell life span increased from 13 days before treatment to 21.6 days after 3 mo of carbamylation. Beyond the 3rd mo of carbamylation, blood P50, hemoglobin, and reticulocytes remained quite stable. No toxic effects of extracorporeal carbamylation of erythrocytes were noted. The capacity of blood to release oxygen at 30 mm Hg Po2 increased from 4.3 to 5.0 cm3/100 ml blood during carbamylation.The overall frequency of severe painful crises decreased by about 80% during carbamylation. Before carbamylation, 34% of the crises were induced by a concomitant illness, usually an infection. During carPortions of this work were presented at the National

One case of May-Hegglin’s anomaly has been described with characteristic findings present also in the mother of the reported case. The propositus showed typical stigmata of the condition: characteristic crescentic, pyroninophilic cytoplasmic patches in a high proportion of polymorphonuclear leukocytes, thrombocytopenia, and giant platelets. The patient’s mother, however, had characteristic patches in only 6 per cent of polymorphonuclear leukocytes and had giant platelets, but was not thrombocytopenic. This is the first patient reported to have such a small proportion of affected polymorphonuclear leukocytes, and suggests that there is variable expression of this genetically determined error of cell differentiation. Other family members did not show hematologic abnormalities. The ultrastructure of leukocytes and platelets from the propositus was investigated, and it was found that: 1. No ultrastructural abnormalities were identified in the lymphocytes and monocytes. 2. Polymorphonuclear neutrophiles had irregular cytoplasmic areas which lacked specific granules and which contained small granules probably glycogen, 50 Å. diameter filaments, and amorphous densities. 3. The fibrils found in the characteristic patches probably consist of RNA. 4. Platelets have apparently normal ultrastructure, but are twice the normal diameter.

Five patients in the Kansas City leukemia surveillance program had a history of multiple myeloma prior to the onset of their acute leukemia. If one applies the Kansas City age/sex‐specific leukemia rates to an estimated population with multiple myeloma living in the study area during the 7‐year collection period, only 0.17 patients would be expected to develop acute leukemia. The five patients presented in this paper represent a significant increase in the observed over the expected incidence. Twenty‐six patients have now been reported who developed acute leukemia during treatment for multiple myeloma, and each had received an alkylating agent. These drugs may be direct leukemogens and the risk involved in their use must be recognized.

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