127 were found to be normotensive, reported by Julius et al.
as
compared
to
the 28%
I would therefore suggest that valid conclusions can be based on home blood-pressure recordings only if the readings obtained by the patients during the early " stage of
accommodation
"
are
disregarded. YEHUDA M. TRAUB, Deputy Head, Hypertension Unit.
Beilinson Hospital, Petah Tiqva, Israel.
ORAL CONTRACEPTIVES AND LIVER TUMOURS SIR,-Your editorial (June 28, p. 1414) prompts me to put on record the relevant observations from the Royal College of General Practitioners’ oral contraception study.l Our latest analyses cover 186,000 women years of observation of all the study subjects-that is, users, previous users, and non-users-and not a single case of a liver tumour has been reported to us. Because of the dramatic way in which they present, it is most unlikely that any such event has These observations prove nothing, gone unrecorded. but they do show how extremely rare these lesions are, and they put into perspective the evidence provided by case-
reports.2 Royal College of General Practitioners, Oral Contraception Study, 8 Barlow Moor Road, Manchester M20 0TR.
CLIFFORD R. KAY, Recorder, Oral Contraception Study.
PLUMBING AND BOWEL HABIT Sirdon’t think you are correct in suspecting that the lavatory seat may inhibit venous drainage of the legs (July 5, p. 18). It comes too far up the thigh to catch the
popliteal vein, which is in any case protected by the hamstrings. Femoral vein and great saphenous are on the medial side of the thigh. Is straining a normal concomitant of defalcation ? I suspect that if you manage things aright it’s more a of aah !than umm ! This has never been a spectator sport, and ever since twin and multi-seater privies went out of fashion, opportunities for observations of healthy adults have been limited. Nevertheless the frequent allusions to straining, both in medical literature and in folklore, compel one to assume it occurs in at least some of the people some of the time. A diet containing vegetable fibre, in particular bran, has been advocated to make things easy. It would be idle to deny that a change of diet, whether an excess of bran, apples, or liquorice allsorts, can change, at least temporarily, " umm " to " aah " .or even " just made it ". What I do question is whether the observed differences in bowel transit times between English and Africans are matter
dietary
in
origin.
Stool bulk is
dependent
on
diet, but
bowel function is also related to central-nervous-system activity induced by habit. Before the introduction of the privy and complicated garments, the child has only to nip round the corner before submitting to his reflexes. The further he gets away from home in the course of play the easier things become; he can squat wherever he is, with no more than a cursory glance for stinging nettles (or snakes in the tropics). But in this country children are dressed in clothing that is difficult for inexpert little hands to adjust, and the privy is, in the words of the Victorians, the necessary place ". To achieve continence children must learn to inhibit the "
1.
Royal College of General Practitioners. Oral Contraceptives and
Health. London, 1974. 2. Baum, J. K., Holtz, F., Bookstein, J. J., ii, 926.
Klein, E. W. Lancet, 1973,
reflex for long periods of time. What with undoing of buttons, and being taken upstairs, ten minutes must be an average time between making a decision to say " Mum I " and relaxing control. Even that assumes that want to go Mum’s hands aren’t covered in pastry and there is no-one else in it. On expeditions away from home the child’s request is greeted with disapproval. It can only be granted after whispered communication with shop assistants. The older child is in little better case. To him parent-child and sib/sib rivalry have a special meaning. The clock also now intervenes. " Hurry up, your Dad has got to get to work ", " You’ll miss the school bus ". Nor will the bus stop on the way. There’s waiting for the mid-morning break, and that means withdrawing from the play of his fellows. So " the shades of the prison house close round the growing boy ", and conditioned inhibition sets in. It’s my belief that, being a resourceful race, we’d learn to inhibit in spite of any feasible consumption of bran. I don’t think our 16th and 17th century forebears would have thought so highly of purgation as a sovereign remedy if they hadn’t been constipated from time to time. So blame the lavatory if you will, but not the seat. Department of Anatomy, The Medical School, Newcastle upon Tyne NE1 7RU.
J. E. GRAY.
COMBINED DIETARY VITAMIN-B12 DEFICIENCY AND BETA-THALASSÆMIA TRAIT
SIR,-We should like to report the characteristics of anaemia due to the association of dietary vitamin-B12 deficiency and &bgr;-thalassaemia trait, occurring in Hindu Asian patients in Britain. These patients do not eat animal products which provide the normal source of vitamin B12 for man,l and there is a carrier-rate of up to 15% for &bgr;-thalassaemia in this population.2 When they present, such patients may be mistakenly labelled neurotic because their insistent complaints of systemic illness seem inappropriate for the mild anaemia, and there are no other clinical signs. There is commonly a hypochromic blood-picture, a reduced mean cell hxmoglobin (M.c.H., normal’ 28-33pg), and the mean cell volume (M.c.v.) is often less than 80fl (normal 76-96fl). P-thalassaemia trait is established by finding a raised percentage of
haemoglobin A2 on haemoglobin electrophoresis (normal 3.5% total haemoglobin). Megaloblastic anaemia may be overlooked as the M.c.v. is in the normal range, although vitamin-B12 deficiency is suggested by the history of strict vegetarianism. It is identified only on bone-marrow The serum-iron concentration and perexamination. centage saturation are normal. Following treatment with oral cyanocobalamin 50 g twice daily, there is a steady decrease in the M.c.v. to below normal levels, as the megaloblastosis resolves and the microcytosis of p-thalassaemia is unmasked. We have seen five patients with this association and the
following
is
typical.
A 40-year-old Indian woman, who had been in England six years after leaving Uganda, presented with malaise, headache, and backache. Her diet excluded animal products apart from milk and some cheese. At presentation the haemoglobin concentration was 112g/dl; M.c.v., 78fl; M.c.H., 26pg; haemoglobin A, 47%; serum-B 11 90ng/l (normal 150-850ng/1); serum-iron 169p.mol (normal 14-29[J.mol); total iron-binding capacity 55-3[mol (normal 45-7[J.mol), and iron saturation 30%. The bone-marrow showed well developed megaloblastic change, but a Schilling test was normal. After treatment with oral vitamin B 11> the haemoglobin concentration rose to 1207g/dl, the M.c.v. reduced to 63fl, and the M.C.H. to 21pg. The percentage 1. 2.
Bannerjee, D. K., Chatterjea, J. B. Br. med. J. 1960, ii, 992. Weatherall, D. J. The Thalassæmia Syndromes; p. 19. Oxford, 1965.
as
compared
to
the 28%
I would therefore suggest that valid conclusions can be based on home blood-pressure recordings only if the readings obtained by the patients during the early " stage of
accommodation
"
are
disregarded. YEHUDA M. TRAUB, Deputy Head, Hypertension Unit.
Beilinson Hospital, Petah Tiqva, Israel.
ORAL CONTRACEPTIVES AND LIVER TUMOURS SIR,-Your editorial (June 28, p. 1414) prompts me to put on record the relevant observations from the Royal College of General Practitioners’ oral contraception study.l Our latest analyses cover 186,000 women years of observation of all the study subjects-that is, users, previous users, and non-users-and not a single case of a liver tumour has been reported to us. Because of the dramatic way in which they present, it is most unlikely that any such event has These observations prove nothing, gone unrecorded. but they do show how extremely rare these lesions are, and they put into perspective the evidence provided by case-
reports.2 Royal College of General Practitioners, Oral Contraception Study, 8 Barlow Moor Road, Manchester M20 0TR.
CLIFFORD R. KAY, Recorder, Oral Contraception Study.
PLUMBING AND BOWEL HABIT Sirdon’t think you are correct in suspecting that the lavatory seat may inhibit venous drainage of the legs (July 5, p. 18). It comes too far up the thigh to catch the
popliteal vein, which is in any case protected by the hamstrings. Femoral vein and great saphenous are on the medial side of the thigh. Is straining a normal concomitant of defalcation ? I suspect that if you manage things aright it’s more a of aah !than umm ! This has never been a spectator sport, and ever since twin and multi-seater privies went out of fashion, opportunities for observations of healthy adults have been limited. Nevertheless the frequent allusions to straining, both in medical literature and in folklore, compel one to assume it occurs in at least some of the people some of the time. A diet containing vegetable fibre, in particular bran, has been advocated to make things easy. It would be idle to deny that a change of diet, whether an excess of bran, apples, or liquorice allsorts, can change, at least temporarily, " umm " to " aah " .or even " just made it ". What I do question is whether the observed differences in bowel transit times between English and Africans are matter
dietary
in
origin.
Stool bulk is
dependent
on
diet, but
bowel function is also related to central-nervous-system activity induced by habit. Before the introduction of the privy and complicated garments, the child has only to nip round the corner before submitting to his reflexes. The further he gets away from home in the course of play the easier things become; he can squat wherever he is, with no more than a cursory glance for stinging nettles (or snakes in the tropics). But in this country children are dressed in clothing that is difficult for inexpert little hands to adjust, and the privy is, in the words of the Victorians, the necessary place ". To achieve continence children must learn to inhibit the "
1.
Royal College of General Practitioners. Oral Contraceptives and
Health. London, 1974. 2. Baum, J. K., Holtz, F., Bookstein, J. J., ii, 926.
Klein, E. W. Lancet, 1973,
reflex for long periods of time. What with undoing of buttons, and being taken upstairs, ten minutes must be an average time between making a decision to say " Mum I " and relaxing control. Even that assumes that want to go Mum’s hands aren’t covered in pastry and there is no-one else in it. On expeditions away from home the child’s request is greeted with disapproval. It can only be granted after whispered communication with shop assistants. The older child is in little better case. To him parent-child and sib/sib rivalry have a special meaning. The clock also now intervenes. " Hurry up, your Dad has got to get to work ", " You’ll miss the school bus ". Nor will the bus stop on the way. There’s waiting for the mid-morning break, and that means withdrawing from the play of his fellows. So " the shades of the prison house close round the growing boy ", and conditioned inhibition sets in. It’s my belief that, being a resourceful race, we’d learn to inhibit in spite of any feasible consumption of bran. I don’t think our 16th and 17th century forebears would have thought so highly of purgation as a sovereign remedy if they hadn’t been constipated from time to time. So blame the lavatory if you will, but not the seat. Department of Anatomy, The Medical School, Newcastle upon Tyne NE1 7RU.
J. E. GRAY.
COMBINED DIETARY VITAMIN-B12 DEFICIENCY AND BETA-THALASSÆMIA TRAIT
SIR,-We should like to report the characteristics of anaemia due to the association of dietary vitamin-B12 deficiency and &bgr;-thalassaemia trait, occurring in Hindu Asian patients in Britain. These patients do not eat animal products which provide the normal source of vitamin B12 for man,l and there is a carrier-rate of up to 15% for &bgr;-thalassaemia in this population.2 When they present, such patients may be mistakenly labelled neurotic because their insistent complaints of systemic illness seem inappropriate for the mild anaemia, and there are no other clinical signs. There is commonly a hypochromic blood-picture, a reduced mean cell hxmoglobin (M.c.H., normal’ 28-33pg), and the mean cell volume (M.c.v.) is often less than 80fl (normal 76-96fl). P-thalassaemia trait is established by finding a raised percentage of
haemoglobin A2 on haemoglobin electrophoresis (normal 3.5% total haemoglobin). Megaloblastic anaemia may be overlooked as the M.c.v. is in the normal range, although vitamin-B12 deficiency is suggested by the history of strict vegetarianism. It is identified only on bone-marrow The serum-iron concentration and perexamination. centage saturation are normal. Following treatment with oral cyanocobalamin 50 g twice daily, there is a steady decrease in the M.c.v. to below normal levels, as the megaloblastosis resolves and the microcytosis of p-thalassaemia is unmasked. We have seen five patients with this association and the
following
is
typical.
A 40-year-old Indian woman, who had been in England six years after leaving Uganda, presented with malaise, headache, and backache. Her diet excluded animal products apart from milk and some cheese. At presentation the haemoglobin concentration was 112g/dl; M.c.v., 78fl; M.c.H., 26pg; haemoglobin A, 47%; serum-B 11 90ng/l (normal 150-850ng/1); serum-iron 169p.mol (normal 14-29[J.mol); total iron-binding capacity 55-3[mol (normal 45-7[J.mol), and iron saturation 30%. The bone-marrow showed well developed megaloblastic change, but a Schilling test was normal. After treatment with oral vitamin B 11> the haemoglobin concentration rose to 1207g/dl, the M.c.v. reduced to 63fl, and the M.C.H. to 21pg. The percentage 1. 2.
Bannerjee, D. K., Chatterjea, J. B. Br. med. J. 1960, ii, 992. Weatherall, D. J. The Thalassæmia Syndromes; p. 19. Oxford, 1965.
