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POTASSIUM SUPPLEMENTS AND DIURETICS
882
Usually no further dilatation of the cervix is required. The normalsize crushing-type ovum forceps will be able to remove the soft fetus and placenta through the dilated cervix without difficulty. The operation is completed by adequate curettage. The maximum volume of blood lost using this method was less than 100 ml. and no patient had a pelvic infection. 10 Harley Street, London W.1.
JOHN SLOME.
FAMILY PLANNING AND ABORTION
patients with cardiac disease requiring long-term treatment with potent diuretics, we found that one-third had an intake of less than 50 meq. per day, and two patients took less than 30 meq. per day.5 Thus, although the information at present is rather limited, it is possible that patients re-
quiring diuretic treatment may be the very ones in whom potassium intake is low. The normal daily intake of potassium is usually taken to be between 65 and 150 meq. per day,6 but the estimation of this does pose difficulties, since the potassium content of fruit and vegetables can vary considerably in different and at different times of year. However, in the face of urinary potassium losses, quoted by Dr. Down et al., of between 50 and 100 meq. per day, it is clear that variations in potassium intake both between individuals and in the same individual are likely to be at least as important as the 48 meq. of potassium supplements supplied with the drug. Perhaps more attention to this aspect of potassium balance will help to clarify the confused picture facing the clinician on the long-term effects of diuretics; in the meantime it is clearly important to ensure that patients requiring this treatment have an adequate potassium intake whether or not potassium supplements are given. areas
SIR,-In the area of contraception and abortion there is already much confused thinking. Your leader (Oct. 7, p. 748) recorded the opinion, to which you give tacit that abortion will always have a support by publication, place in family planning as in population planning ". You quote a National Opinion Poll Survey as showing that 65% of people in England favour a Government-provided comprehensive family-planning and birth-control service. However, there is no evidence that these 65% favour abortion as a method of family planning or population planning. Contraception and abortion are medically and ethically discrete entities. Juxtaposition of the two in a manner likely to obscure rather than clarify the differences is unhelpful. It is unwise to accept uncritically the I.P.P.F. report by " experts on abortion " who come to the conclusion that " Induced abortion plays a significant role in the control of human fertility and is an important factor in the decline in birth rates, especially in urbanized communities ". It is by no means certain this report " will have worldwide influence upon the thinking of family-planning "
associations and Governments ". University Department of Obstetrics and Gynæcology, 17 Springfield Mount, Leeds LS2 9NG.
D. M. JENKINS.
POTASSIUM SUPPLEMENTS AND DIURETICS
University Department of Medicine, General Infirmary, Leeds 1.
THE ELDERLY AMPUTEE
SIR,-Your editorial (Oct. 7, p. 747) (the elderly amputee) draws attention to the fact (which we can endorse from our experience in Cardiff 7) that most vascular amputees can be provided with a below-knee stump, with all the benefits in rehabilitation that this confers. It should be pointed out, however, that a high successrate depends upon the use of a long posterior flap. The old operation with an anterior flap does badly in patients with ischsemia, and is responsible for the profound prejudice against amputation at this level. University Hospital of Wales, Heath Park, Cardiff
SIR,-The paper of Dr. Down and his colleagues (Oct. 7, p. 721) supports the view that potassium supplements do little to affect either plasma-potassium or exchangeable potassium in patients on diuretics. This is in complete another paper in The Lancet1 in which a consistent fall in total body-potassium during diuretic treatThe ment was corrected by potassium supplements. confusion on this subject has been reviewed by Anderson et al.,2 who could offer no explanation for the discrepancies between the results of different workers. It is surprising that none of these authors have taken into account variations in dietary potassium intake as a possible source for these discrepancies. The reason for this is perhaps historical, since most of the work on dietetics and the composition of food was undertaken before the advent of modern diuretics and potassium deficiency had become a clinical problem. However, closer examination of certain groups of patients suggests that a low potassium intake may occur more frequently than is generally recognised. Thus Dall and Gardiner3 found that geriatric patients took less than 50 meq. per day even when fully ambulant, mainly as a result of a poor choice of food. Anorexia from any cause may give a low dietary potassium, and this was felt to contribute to the 4 In poor potassium intake found in cirrhotic patients.
CF4 4XW.
Edmonds, C. J., Jasani, B. Lancet, July 1, 1972, p. 8. Anderson, J., Godfrey, B. E., Hill, D. M., Munro-Faure, A. D Sheldon, J. Q. Jl Med. 1971, 40, 160. 3. Dall, J. L. C., Gardiner, H. S. Geront. Clin. 1971, 13, 119. 4. Senewirantine, B., Sherlock, S. Lancet, 1968, i, 120.
GORDON HEARD.
ROSETTE FORMATION
contrast to
1. 2.
C. DAVIDSON
SIR; The preliminary communication of Dr. Papamichail and others (July 8, p. 64) presents further evidence that there are two distinct populations of lymphocytes in human peripheral blood (P.B.L.). Cells which bear surface Ig determinants (20-30% of the total) are thought to be B cells. They suggest that cells which form rosettes with sheep erythrocytes (29%) are part of a T-cell population, and that the ratio of T/B cells thus determined may be useful. Stjernsward et al.11 also use the percentage of rosette-forming cells (R.F.c.) as a measure of T cells. I should like to comment on the use of rosette formation as a measure of T cells. I found that for several different cell types only 10-20% of P.B.L. formed rosettes. After washing these cells in Hanks’ B.S.S. six times, the perWhen these cells were recentage rose to 50-73. suspended in 5% normal human serum, the percentage fell to 10-15. This suggests the presence of a material which normally masks the sheep-red-blood-cell receptor on human lymphocytes. This dramatic change in percentage of R.F.C. following 5. 6. 7. 8.
Davidson, C., Gillebrand, I. Unpublished. Davidson, S., Passmore, R. Human Nutrition and Dietetics; p. 136, Edinburgh, 1966. Gay, R., Heard, G. Ir. J. med. Sci. 1972, 141, 25. Lancet, 1972, i, 1352.
Usually no further dilatation of the cervix is required. The normalsize crushing-type ovum forceps will be able to remove the soft fetus and placenta through the dilated cervix without difficulty. The operation is completed by adequate curettage. The maximum volume of blood lost using this method was less than 100 ml. and no patient had a pelvic infection. 10 Harley Street, London W.1.
JOHN SLOME.
FAMILY PLANNING AND ABORTION
patients with cardiac disease requiring long-term treatment with potent diuretics, we found that one-third had an intake of less than 50 meq. per day, and two patients took less than 30 meq. per day.5 Thus, although the information at present is rather limited, it is possible that patients re-
quiring diuretic treatment may be the very ones in whom potassium intake is low. The normal daily intake of potassium is usually taken to be between 65 and 150 meq. per day,6 but the estimation of this does pose difficulties, since the potassium content of fruit and vegetables can vary considerably in different and at different times of year. However, in the face of urinary potassium losses, quoted by Dr. Down et al., of between 50 and 100 meq. per day, it is clear that variations in potassium intake both between individuals and in the same individual are likely to be at least as important as the 48 meq. of potassium supplements supplied with the drug. Perhaps more attention to this aspect of potassium balance will help to clarify the confused picture facing the clinician on the long-term effects of diuretics; in the meantime it is clearly important to ensure that patients requiring this treatment have an adequate potassium intake whether or not potassium supplements are given. areas
SIR,-In the area of contraception and abortion there is already much confused thinking. Your leader (Oct. 7, p. 748) recorded the opinion, to which you give tacit that abortion will always have a support by publication, place in family planning as in population planning ". You quote a National Opinion Poll Survey as showing that 65% of people in England favour a Government-provided comprehensive family-planning and birth-control service. However, there is no evidence that these 65% favour abortion as a method of family planning or population planning. Contraception and abortion are medically and ethically discrete entities. Juxtaposition of the two in a manner likely to obscure rather than clarify the differences is unhelpful. It is unwise to accept uncritically the I.P.P.F. report by " experts on abortion " who come to the conclusion that " Induced abortion plays a significant role in the control of human fertility and is an important factor in the decline in birth rates, especially in urbanized communities ". It is by no means certain this report " will have worldwide influence upon the thinking of family-planning "
associations and Governments ". University Department of Obstetrics and Gynæcology, 17 Springfield Mount, Leeds LS2 9NG.
D. M. JENKINS.
POTASSIUM SUPPLEMENTS AND DIURETICS
University Department of Medicine, General Infirmary, Leeds 1.
THE ELDERLY AMPUTEE
SIR,-Your editorial (Oct. 7, p. 747) (the elderly amputee) draws attention to the fact (which we can endorse from our experience in Cardiff 7) that most vascular amputees can be provided with a below-knee stump, with all the benefits in rehabilitation that this confers. It should be pointed out, however, that a high successrate depends upon the use of a long posterior flap. The old operation with an anterior flap does badly in patients with ischsemia, and is responsible for the profound prejudice against amputation at this level. University Hospital of Wales, Heath Park, Cardiff
SIR,-The paper of Dr. Down and his colleagues (Oct. 7, p. 721) supports the view that potassium supplements do little to affect either plasma-potassium or exchangeable potassium in patients on diuretics. This is in complete another paper in The Lancet1 in which a consistent fall in total body-potassium during diuretic treatThe ment was corrected by potassium supplements. confusion on this subject has been reviewed by Anderson et al.,2 who could offer no explanation for the discrepancies between the results of different workers. It is surprising that none of these authors have taken into account variations in dietary potassium intake as a possible source for these discrepancies. The reason for this is perhaps historical, since most of the work on dietetics and the composition of food was undertaken before the advent of modern diuretics and potassium deficiency had become a clinical problem. However, closer examination of certain groups of patients suggests that a low potassium intake may occur more frequently than is generally recognised. Thus Dall and Gardiner3 found that geriatric patients took less than 50 meq. per day even when fully ambulant, mainly as a result of a poor choice of food. Anorexia from any cause may give a low dietary potassium, and this was felt to contribute to the 4 In poor potassium intake found in cirrhotic patients.
CF4 4XW.
Edmonds, C. J., Jasani, B. Lancet, July 1, 1972, p. 8. Anderson, J., Godfrey, B. E., Hill, D. M., Munro-Faure, A. D Sheldon, J. Q. Jl Med. 1971, 40, 160. 3. Dall, J. L. C., Gardiner, H. S. Geront. Clin. 1971, 13, 119. 4. Senewirantine, B., Sherlock, S. Lancet, 1968, i, 120.
GORDON HEARD.
ROSETTE FORMATION
contrast to
1. 2.
C. DAVIDSON
SIR; The preliminary communication of Dr. Papamichail and others (July 8, p. 64) presents further evidence that there are two distinct populations of lymphocytes in human peripheral blood (P.B.L.). Cells which bear surface Ig determinants (20-30% of the total) are thought to be B cells. They suggest that cells which form rosettes with sheep erythrocytes (29%) are part of a T-cell population, and that the ratio of T/B cells thus determined may be useful. Stjernsward et al.11 also use the percentage of rosette-forming cells (R.F.c.) as a measure of T cells. I should like to comment on the use of rosette formation as a measure of T cells. I found that for several different cell types only 10-20% of P.B.L. formed rosettes. After washing these cells in Hanks’ B.S.S. six times, the perWhen these cells were recentage rose to 50-73. suspended in 5% normal human serum, the percentage fell to 10-15. This suggests the presence of a material which normally masks the sheep-red-blood-cell receptor on human lymphocytes. This dramatic change in percentage of R.F.C. following 5. 6. 7. 8.
Davidson, C., Gillebrand, I. Unpublished. Davidson, S., Passmore, R. Human Nutrition and Dietetics; p. 136, Edinburgh, 1966. Gay, R., Heard, G. Ir. J. med. Sci. 1972, 141, 25. Lancet, 1972, i, 1352.