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INFLUENZAL WOOD AND TREES
36 INFLUENZAL WOOD AND TREES THOSE engaged in typing influenza viruses have long envied their colleagues concerned with similar problems among bacteria. Thus, salmonellae have a mere threehundred-odd serological types, while the pneumococcus and the diphtheria bacillus can boast little more than sixty. Compared with these figures, the number of serological subtypes of the influenza-A viruses seems to the investigator as the sands of the sea. It is- with real gratitude, therefore, that- he will turn to a recent account, by Dr. George K. Hirst,l of an attempt to introduce greater order into the serological study of these
viruses. Conventional serological methods measure at the time qualitative and quantitative differences in antigenic composition of influenza viruses. Hirst has studied a large number of strains with virus-absorbed sera which indicate qualitative differences only. Among influenza virus strains isolated between’ 1933 and 1947 Hirst finds six main type-specific antigenic components, though there are strong hints of more to come. With one exception all the strains studied showed only one type-specific component, along with a group-specific antigen which is common to most of the strains and The bewildering confers’ the influenza-A characters. variety in the antigenic make-up of the influenza viruses is accounted for by quantitative variations in these basic components. To those who are not serologically minded it will come as a relief that when the minutiae of the trees have been explored we get a fascinating picture of the wood. The general pattern which emerges is that one type-specific antigen at a time is widely distributed throughout the world for a few years until it is replaced by a new antigen, which then dominates the scene for a few more years. The occurrence of a new antigen is so rare in comparison with the large numbers of serologically similar strains which have been found during one epidemic period that we have no reasonable alternative to the view that mutation of the virus has occurred on a single occasion, followed by widespread dissemination of the new antigenic subtype. The dominance of the new type and the disappearance of the older types is readily explained by widespread immunity to the latter. same
I
Presumably, therefore,- virus bearing which is closely related serologically to
a
new
antigen
its predecessors which is distantly
will appear less " virulent " than one related. Studies with virus-absorbed sera have been few Hirst’s because of the many technical difficulties. illuminates done much that has been conby technique ventional serological methods, although it is unlikely to replace them in general use. Like much of Hirst’s
previous work, this unspectacular study gives enough foundation to bear the weight of much speculation.
a
sure
future
&mid ot;
CORTISONE IN PREGNANCY THE effect of cortisone in pregnancy deserves special assessment ; and the subject has had relatively little attention. Pregnancy is associated with retention of water and sodium, and with an increased urinary output of corticoids - ; and both these changes indicate special activity in the mother’s adrenal cortex. The case of the patient who becomes pregnant while under treatment with cortisone raises the question of its effects on reproduction and gestation. In rabbits De Costa and Abelman 3 found that cortisone interfered with conception, when given in 15 mg. doses daily for several days before mating, but it had little 1. Hirst, G. K. J. exp. Med. 1952, 96, 589. 2. Venning, E. H. Endocrinology, 1946, 39, 203. 3. De Costa, E. J., Abelman, M. A. Amer. J. Obstet.
64, 746.
Gynec. 1952,
effect does
conception when given after mating. Pregnant given cortisone daily for various periods throughout gestation, and only a third of them In the rabbit, therefore, gave birth to live young. on
were
cortisone seems to lower the chances of a successful pregnancy. In women the effect of cortisone on menstruation is variable, but a succession of normal menstrual cycles De Costa and is common enough during treatment. Abelman described 5 cases in which cortisone was given during pregnancy. In 2 of these cases (rheumatoid arthritis and reactivated rheumatic fever) conception took place during a long period of treatment with cortisone ; 1 woman aborted spontaneously two months after treatment was stopped, and in the second therapeutic abortion became necessary ; in both cases the faetus and In the 3 other pregnancies were normal. cortisone given in mid-gestation or later seemed to have no effect on the pregnancy, and live healthy babies were delivered. Doerner et al.,4 in an attempt to influencerhesus sensitisation, gave cortisone to 2 women in the later months of pregnancy. Neither showed untoward reactions ; but there was no appreciable change in antibodies. While the published evidence is somewhat scanty, it seems that cortisone is harmless in human pregnancy, at any rate when given after the sixteenth week. Possibly cortisone causes a release of oestrogens ;;. and it is known that oestrogens cause abortion in rabbits, but not in women. In conditions complicating pregnancy the possible effect of cortisone on the pregnancy may be a consideration secondary to its effect on the complicating disease. In toxaemia the role of the adrenal gland is obscure, and it may be argued that the salt-retaining properties of cortisone could precipitate convulsions in a pre-eclamptic patient. Indeed, fatal convulsions, though rare, are not unknown during cortisone therapv.5 However, the beneficial effects of cortisone on the oedema of nephritis11 encouraged Moore and his colleaguesto give cortisone to 8 patients with toxaemia in whom termination of pregnancy was indicated. In all 8 there was considerable clinical improvement, and 7 of the women were delivered of live babies. The results in this small series are hopeful, and provide another example of the versatility of cortisone in modifying symptoms. Clearly, however, this drug should at present be used warily in early pregnancyin hyperemesis, for instance.
placenta
-
--
VACANCIES
BEFORE the late
war we published each week a list the vacant appointments for which applications were invited in our advertisement columns. In- 1940 these lists were discontinued so as to make space for other purposes; but we are now resuming their publication in a different and more useful form. In the weekly summary, which in this issue appears on the last three pages of our text, the vacancies will be classified according to the nature of the appointment-e.g., obstetrical, psychiatric, or casualty. In our advertisement columns, which remain unchanged, the hospital will, as before, be classified into senior and junior and then be arranged geographically. The supplementary summary which is now to be provided should, however, make it far easier for readers to find the items in which they are interested. The advantages of the existing classification will remain, but the new and separate classification will, we hope, remove its disadvantages.
of
appointments
A., Naegele, C. F., Regan, F. D., Shanapley, J. F., Edwards, W. B. J. Amer. med. Ass. 1951, 147, 1099. 5. Geppert, L. J., Dietriek, A. C., Johnston, E. H., Lind, C. J. Amer. J. Dis. Child. 1952, 84, 416. 6. Farnsworth, E. B. Proceedings of 1st Clinical A.C.T.H. Conference. Philadelphia and London, 1950 ; p. 297. 7. Moore, H., Jessop, W. J. E., O’Donovan, D. K.. Barry, A. P., Quinn, B., Drury, M. I. Brit. med. J. 1951, i, 840.
4. Doerner, A.
viruses. Conventional serological methods measure at the time qualitative and quantitative differences in antigenic composition of influenza viruses. Hirst has studied a large number of strains with virus-absorbed sera which indicate qualitative differences only. Among influenza virus strains isolated between’ 1933 and 1947 Hirst finds six main type-specific antigenic components, though there are strong hints of more to come. With one exception all the strains studied showed only one type-specific component, along with a group-specific antigen which is common to most of the strains and The bewildering confers’ the influenza-A characters. variety in the antigenic make-up of the influenza viruses is accounted for by quantitative variations in these basic components. To those who are not serologically minded it will come as a relief that when the minutiae of the trees have been explored we get a fascinating picture of the wood. The general pattern which emerges is that one type-specific antigen at a time is widely distributed throughout the world for a few years until it is replaced by a new antigen, which then dominates the scene for a few more years. The occurrence of a new antigen is so rare in comparison with the large numbers of serologically similar strains which have been found during one epidemic period that we have no reasonable alternative to the view that mutation of the virus has occurred on a single occasion, followed by widespread dissemination of the new antigenic subtype. The dominance of the new type and the disappearance of the older types is readily explained by widespread immunity to the latter. same
I
Presumably, therefore,- virus bearing which is closely related serologically to
a
new
antigen
its predecessors which is distantly
will appear less " virulent " than one related. Studies with virus-absorbed sera have been few Hirst’s because of the many technical difficulties. illuminates done much that has been conby technique ventional serological methods, although it is unlikely to replace them in general use. Like much of Hirst’s
previous work, this unspectacular study gives enough foundation to bear the weight of much speculation.
a
sure
future
&mid ot;
CORTISONE IN PREGNANCY THE effect of cortisone in pregnancy deserves special assessment ; and the subject has had relatively little attention. Pregnancy is associated with retention of water and sodium, and with an increased urinary output of corticoids - ; and both these changes indicate special activity in the mother’s adrenal cortex. The case of the patient who becomes pregnant while under treatment with cortisone raises the question of its effects on reproduction and gestation. In rabbits De Costa and Abelman 3 found that cortisone interfered with conception, when given in 15 mg. doses daily for several days before mating, but it had little 1. Hirst, G. K. J. exp. Med. 1952, 96, 589. 2. Venning, E. H. Endocrinology, 1946, 39, 203. 3. De Costa, E. J., Abelman, M. A. Amer. J. Obstet.
64, 746.
Gynec. 1952,
effect does
conception when given after mating. Pregnant given cortisone daily for various periods throughout gestation, and only a third of them In the rabbit, therefore, gave birth to live young. on
were
cortisone seems to lower the chances of a successful pregnancy. In women the effect of cortisone on menstruation is variable, but a succession of normal menstrual cycles De Costa and is common enough during treatment. Abelman described 5 cases in which cortisone was given during pregnancy. In 2 of these cases (rheumatoid arthritis and reactivated rheumatic fever) conception took place during a long period of treatment with cortisone ; 1 woman aborted spontaneously two months after treatment was stopped, and in the second therapeutic abortion became necessary ; in both cases the faetus and In the 3 other pregnancies were normal. cortisone given in mid-gestation or later seemed to have no effect on the pregnancy, and live healthy babies were delivered. Doerner et al.,4 in an attempt to influencerhesus sensitisation, gave cortisone to 2 women in the later months of pregnancy. Neither showed untoward reactions ; but there was no appreciable change in antibodies. While the published evidence is somewhat scanty, it seems that cortisone is harmless in human pregnancy, at any rate when given after the sixteenth week. Possibly cortisone causes a release of oestrogens ;;. and it is known that oestrogens cause abortion in rabbits, but not in women. In conditions complicating pregnancy the possible effect of cortisone on the pregnancy may be a consideration secondary to its effect on the complicating disease. In toxaemia the role of the adrenal gland is obscure, and it may be argued that the salt-retaining properties of cortisone could precipitate convulsions in a pre-eclamptic patient. Indeed, fatal convulsions, though rare, are not unknown during cortisone therapv.5 However, the beneficial effects of cortisone on the oedema of nephritis11 encouraged Moore and his colleaguesto give cortisone to 8 patients with toxaemia in whom termination of pregnancy was indicated. In all 8 there was considerable clinical improvement, and 7 of the women were delivered of live babies. The results in this small series are hopeful, and provide another example of the versatility of cortisone in modifying symptoms. Clearly, however, this drug should at present be used warily in early pregnancyin hyperemesis, for instance.
placenta
-
--
VACANCIES
BEFORE the late
war we published each week a list the vacant appointments for which applications were invited in our advertisement columns. In- 1940 these lists were discontinued so as to make space for other purposes; but we are now resuming their publication in a different and more useful form. In the weekly summary, which in this issue appears on the last three pages of our text, the vacancies will be classified according to the nature of the appointment-e.g., obstetrical, psychiatric, or casualty. In our advertisement columns, which remain unchanged, the hospital will, as before, be classified into senior and junior and then be arranged geographically. The supplementary summary which is now to be provided should, however, make it far easier for readers to find the items in which they are interested. The advantages of the existing classification will remain, but the new and separate classification will, we hope, remove its disadvantages.
of
appointments
A., Naegele, C. F., Regan, F. D., Shanapley, J. F., Edwards, W. B. J. Amer. med. Ass. 1951, 147, 1099. 5. Geppert, L. J., Dietriek, A. C., Johnston, E. H., Lind, C. J. Amer. J. Dis. Child. 1952, 84, 416. 6. Farnsworth, E. B. Proceedings of 1st Clinical A.C.T.H. Conference. Philadelphia and London, 1950 ; p. 297. 7. Moore, H., Jessop, W. J. E., O’Donovan, D. K.. Barry, A. P., Quinn, B., Drury, M. I. Brit. med. J. 1951, i, 840.
4. Doerner, A.