PLATES XXVIII AND XXIX) IN a previous paper (Israels, 1940) I described the application of a, modification of Osgood and Brownlee's (1937) technique to the study of leucocytes from the bone marrow of cases of leukaemia. The changes that occurred in the main groups of leucocytes were observed and it was found that under these experimental conditions granulocytes, lymphocytes and monocytes displayed different modes of development. In this paper results of the cultivation of marrow cells from further patients with leukaemia are given and the evidence from these and the previous experiments is uszd as the basis for a discussion of the nature of human leukaemia.
Case 1Clinical notes. A girl typist aged 20, twelve weeks before admission to hospital, had had severe opistaxis and pain in various joints. Later there was bleeding from the gums and dyspncea on exertion. Increasing pallor became alarming. No rashes occurred. Menstruation was regular and the loss not excessive. Therc was nothing significant in the previous medical or family history. Examination showed a very pale patient with a few small petechiz in the skin. Therc had been a recent epistaxis. The gums were soft and bled when touched. The spleen and liver were palpable about 2 in. below the costal margins. The lymph glands were not enlarged. Haemorrhages were found in both r e t i n e The blood count showed: red cells 2,160,000 per c.mm., hemoglobin 41 per cent., colour index 0.95, white cells 32,000 per c.mm. The differential white cell count and the result of sternal puncture are given in the table; they indicated acute leukaemia, probably myeloid. The patient was given repeated blood transfusions, but her condition became distressing owing t o increased hsmorrhages from nose and gums. Ten weeks later she left hospital and her death was reported shortly after.Cultures of the bone marrow cells. After 24 hours embryonic cells were numerous and several showed early stages of mitosis ( fig. 1). Both early and differentiated myelocytes were present, also in 235 This Journal, xlvii, 457. Brit. Med. J., ii. 1029. A m r .