676 appears to occur in vivo: xenografts of AML cells often grow for a time in immune-deprived mice and maturation is evident in the human AML cells in the modules
produced. 10
methods aimed at preventing the changes which favour reversion to immature blast cell growth.
treatment
We thank the Leukaemia Research Fund for support.
Requests for reprints should be addressed to R.L.P.
The maturation of AML cells in vitro and in immunosuppressed mice suggests that the environment of the leukaemic host creates conditions in which AML cells can grow without maturing. Induction chemotherapy, by reducing the load of leukaemia cells and restoring normal marrow function, may establish an environment in which, for a time, maturation predominates and leukasmic cells which have matured are not killed by chemotherapy. Thus in remission the few remaining "leukaemic" cells persist in a more differentiated state and, although capable of division, they are not eliminated by the drugs. Eventually this clone of cells again dominates the normal marrow but florid relapse does not occur until these cells lose their capacity to differentiate. Relapse, therefore, is associated with a switch to a non-maturing growth pattern. Remission therapy should thus be aimed at the elimination of cells growing by the maturing pathway, perhaps by promoting maturation to the point at which the cells lose the capacity to revert and eventually die of "old age". This may, by necessity, require additional
Reviews of Books An Introduction to Radiation Dosimetry
Techniques of Measurement in Medicine, Vol. IV. S. LOVELL, St. Bartholomew’s Hospital, London. Cambridge: Cambridge University Press. 1979. Pp. 113. £7.00; £2.500 (paper- back). MAN has evolved in an environment which has a low flux of ionising radiation and hence such radiation is "natural" for him. Despite this, most of the biological effects of ionising radiation are harmful, so that every effort should be made to increase exposure as little as possible above that from the natural background. This objective cannot be achieved unless the radiation can be measured, and how this is done is what Dr Lovell sets out in this book. In view of the widespread use of ionising radiation in industry as well as in medicine, all doctors should have sufficient knowledge of the subject to enable them to deal with their patients’ questions about dangers and benefits. This book is probably more detailed than the average doctor would wish it to be, but the reader will find the style clear and precise. It is thoroughly up-to-date, uses SI units throughout, and defines each unit as it is introduced. Mathematics is reduced to a minimum and, where it has to be used, an elementary approach has been adopted. The book can be most strongly recommended to those doctors whose work requires them to have a particular knowledge of the subjectindustrial medical officers, radiologists, radiotherapists, nuclear medicine specialists-as well as to those people concerned with safety and with environmental issues. A study of this book will help them to collaborate with their physicist col-
leagues more easily. University of Toronto, Quest. 1979. Pp. 300.
$1S;/:10.20. IN Britain children have
ASD. The treatment of acute myeloid leukæmia in adults. In: Therapy of acute leukæmias. Rome; Lombardo Editore. Mandelli F, ed. 1979 414-22. 2. Powles RL, Russell J, Lister TA, et al. Immunotherapy for acute myelogenous leukæmia: a controlled clinical study 2½ years after entry of the last patient. Br J Cancer 1977; 35: 265-72. 3. Powles RL. Pitfalls in analysis of survival in clinical trials. Biomedicine 1.
Spiers
1976; 24: 327-28. 4. Powles RL, Palu G, Raghavan D. The curability of acute leukæmia. In: Topical reviews of hæmatology. Roath J. ed. London; John Wright (in
press). 5. Metcalf D. The nature of myeloid leukæmia. Ninth annual guest lecture. London; Leukaemia Research Fund, 1979. 6. Sachs L. The differentiation of myeloid leukæmia cells: new possibilities for therapy. Br J Hœmatol 1978; 40: 509-17. 7. Collins SJ, Ruscetti FW, Gallagher RC, Gallo RC. Terminal differentiation of human promyelocytic leukæmia cells induced by dimethyl sulphoxide and other polar compounds. Proc Natl Acad Sci U.S.A. 1978; 75: 2458-62. 8. Chapuis B, Cocks P, Powles RL. In-vitro proliferative growth of acute myeloid leukæmia (AML) cells cryopreserved for active specific immunotherapy. Cryoimmunologie INSERM 1976; 62: 347-54. 9. Palu G, Powles RL, Selby P, Summersgill BM, Alexander P. Patterns of maturation in short-term culture of human acute myeloid leukæmic cells. Br J Cancer (in press). 10. Palu G, Selby P, Powles R, Alexander P. Spontaneous regression of human acute myeloid leukæmia xenografts and phenotypic evidence for maturation in vivo and in vitro. Br J Cancer (in press).
Toronto is useful. Its chief strength is that it provides a good overall view of the possible causes of learning failure in children whose intelligence is otherwise average or aboveaverage. The generous scope given to this topic, however, is a source of weakness, in that nothing can be described at any length. Only two pages, for example, are allocated to dyslexia, and any attempt to describe principles of psychotherapy in different contexts here can only be superficial. Even so, it is always instructive to get at least some idea of how practitioners in different countries tackle similar problems and, although the diagnostic tests and procedures mentioned will not always be familiar to those outside Canada and the U.S.A., there are enough useful tips and suggestions to stimulate those who may normally take a different line. Both authors, for example, place a good deal of emphasis on the idea of a special "learning clinic", in some ways similar to child guidance clinics in Britain, but in other respects different in some quite interesting ways. They also stress the need to differentiate between learning and motivational disorders, and although both can seem at times so strongly interconnected that attempts to separate them are almost impossible, it is refreshing at least to read their point of view. Lastly, this book can most certainly be welcomed for its clear and pleasing prose-by no means always a feature of studies of communication difficulties.
Neurological Epidemiology Advances in Neurology, Vol. XIX. Edited by BRUCE S. SCHOENBERG, National Institute of Neurological and Communicative Disorders and Stroke, National Institutes of Health, Bethesda. NeBt York: Raven Press. 1978. Pp. 660.$58.50.
THIS useful reference book is
organised
in
two
parts. The
first, which deals with principles of neuroepidemiology,
Children’s Learning and Attention Problems MARCEL KINSBOURNE and PAULA CAPLAN, Ontario. Boston: Little, Brown; London:
REFERENCES
learning difficulties; in Canada, such children are described as "learning disabled", suffering either from "cognitive power disorder" (learning disorders) or from "cognitive style disorder" (attention problems). But once one has become used to the jargon, this study by a Canadian paediatrician and his psychologist colleague at the University of
ter-
minology, methodology, and sources of information and which explains the interaction between neuroepidemiology and the other neurosciences, should provide the reader with a basis on which to judge the validity and usefulness of scientific reports. The second describes the epidemiology of acute and chromc neurological diseases and that of the neurological comphcations of other diseases. However, although the difference in prevalence of multiple sclerosis between high and low prevalence areas is greater than that in other neurological diseases. there is no comment on what happens to those who migrate from low to high prevalence areas.
produced. 10
methods aimed at preventing the changes which favour reversion to immature blast cell growth.
treatment
We thank the Leukaemia Research Fund for support.
Requests for reprints should be addressed to R.L.P.
The maturation of AML cells in vitro and in immunosuppressed mice suggests that the environment of the leukaemic host creates conditions in which AML cells can grow without maturing. Induction chemotherapy, by reducing the load of leukaemia cells and restoring normal marrow function, may establish an environment in which, for a time, maturation predominates and leukasmic cells which have matured are not killed by chemotherapy. Thus in remission the few remaining "leukaemic" cells persist in a more differentiated state and, although capable of division, they are not eliminated by the drugs. Eventually this clone of cells again dominates the normal marrow but florid relapse does not occur until these cells lose their capacity to differentiate. Relapse, therefore, is associated with a switch to a non-maturing growth pattern. Remission therapy should thus be aimed at the elimination of cells growing by the maturing pathway, perhaps by promoting maturation to the point at which the cells lose the capacity to revert and eventually die of "old age". This may, by necessity, require additional
Reviews of Books An Introduction to Radiation Dosimetry
Techniques of Measurement in Medicine, Vol. IV. S. LOVELL, St. Bartholomew’s Hospital, London. Cambridge: Cambridge University Press. 1979. Pp. 113. £7.00; £2.500 (paper- back). MAN has evolved in an environment which has a low flux of ionising radiation and hence such radiation is "natural" for him. Despite this, most of the biological effects of ionising radiation are harmful, so that every effort should be made to increase exposure as little as possible above that from the natural background. This objective cannot be achieved unless the radiation can be measured, and how this is done is what Dr Lovell sets out in this book. In view of the widespread use of ionising radiation in industry as well as in medicine, all doctors should have sufficient knowledge of the subject to enable them to deal with their patients’ questions about dangers and benefits. This book is probably more detailed than the average doctor would wish it to be, but the reader will find the style clear and precise. It is thoroughly up-to-date, uses SI units throughout, and defines each unit as it is introduced. Mathematics is reduced to a minimum and, where it has to be used, an elementary approach has been adopted. The book can be most strongly recommended to those doctors whose work requires them to have a particular knowledge of the subjectindustrial medical officers, radiologists, radiotherapists, nuclear medicine specialists-as well as to those people concerned with safety and with environmental issues. A study of this book will help them to collaborate with their physicist col-
leagues more easily. University of Toronto, Quest. 1979. Pp. 300.
$1S;/:10.20. IN Britain children have
ASD. The treatment of acute myeloid leukæmia in adults. In: Therapy of acute leukæmias. Rome; Lombardo Editore. Mandelli F, ed. 1979 414-22. 2. Powles RL, Russell J, Lister TA, et al. Immunotherapy for acute myelogenous leukæmia: a controlled clinical study 2½ years after entry of the last patient. Br J Cancer 1977; 35: 265-72. 3. Powles RL. Pitfalls in analysis of survival in clinical trials. Biomedicine 1.
Spiers
1976; 24: 327-28. 4. Powles RL, Palu G, Raghavan D. The curability of acute leukæmia. In: Topical reviews of hæmatology. Roath J. ed. London; John Wright (in
press). 5. Metcalf D. The nature of myeloid leukæmia. Ninth annual guest lecture. London; Leukaemia Research Fund, 1979. 6. Sachs L. The differentiation of myeloid leukæmia cells: new possibilities for therapy. Br J Hœmatol 1978; 40: 509-17. 7. Collins SJ, Ruscetti FW, Gallagher RC, Gallo RC. Terminal differentiation of human promyelocytic leukæmia cells induced by dimethyl sulphoxide and other polar compounds. Proc Natl Acad Sci U.S.A. 1978; 75: 2458-62. 8. Chapuis B, Cocks P, Powles RL. In-vitro proliferative growth of acute myeloid leukæmia (AML) cells cryopreserved for active specific immunotherapy. Cryoimmunologie INSERM 1976; 62: 347-54. 9. Palu G, Powles RL, Selby P, Summersgill BM, Alexander P. Patterns of maturation in short-term culture of human acute myeloid leukæmic cells. Br J Cancer (in press). 10. Palu G, Selby P, Powles R, Alexander P. Spontaneous regression of human acute myeloid leukæmia xenografts and phenotypic evidence for maturation in vivo and in vitro. Br J Cancer (in press).
Toronto is useful. Its chief strength is that it provides a good overall view of the possible causes of learning failure in children whose intelligence is otherwise average or aboveaverage. The generous scope given to this topic, however, is a source of weakness, in that nothing can be described at any length. Only two pages, for example, are allocated to dyslexia, and any attempt to describe principles of psychotherapy in different contexts here can only be superficial. Even so, it is always instructive to get at least some idea of how practitioners in different countries tackle similar problems and, although the diagnostic tests and procedures mentioned will not always be familiar to those outside Canada and the U.S.A., there are enough useful tips and suggestions to stimulate those who may normally take a different line. Both authors, for example, place a good deal of emphasis on the idea of a special "learning clinic", in some ways similar to child guidance clinics in Britain, but in other respects different in some quite interesting ways. They also stress the need to differentiate between learning and motivational disorders, and although both can seem at times so strongly interconnected that attempts to separate them are almost impossible, it is refreshing at least to read their point of view. Lastly, this book can most certainly be welcomed for its clear and pleasing prose-by no means always a feature of studies of communication difficulties.
Neurological Epidemiology Advances in Neurology, Vol. XIX. Edited by BRUCE S. SCHOENBERG, National Institute of Neurological and Communicative Disorders and Stroke, National Institutes of Health, Bethesda. NeBt York: Raven Press. 1978. Pp. 660.$58.50.
THIS useful reference book is
organised
in
two
parts. The
first, which deals with principles of neuroepidemiology,
Children’s Learning and Attention Problems MARCEL KINSBOURNE and PAULA CAPLAN, Ontario. Boston: Little, Brown; London:
REFERENCES
learning difficulties; in Canada, such children are described as "learning disabled", suffering either from "cognitive power disorder" (learning disorders) or from "cognitive style disorder" (attention problems). But once one has become used to the jargon, this study by a Canadian paediatrician and his psychologist colleague at the University of
ter-
minology, methodology, and sources of information and which explains the interaction between neuroepidemiology and the other neurosciences, should provide the reader with a basis on which to judge the validity and usefulness of scientific reports. The second describes the epidemiology of acute and chromc neurological diseases and that of the neurological comphcations of other diseases. However, although the difference in prevalence of multiple sclerosis between high and low prevalence areas is greater than that in other neurological diseases. there is no comment on what happens to those who migrate from low to high prevalence areas.
