- Email: [email protected]
VITAMIN B12 AND THYROID FUNCTION
327 is allowed to come directly in contact with the rubber. It appears to me that a combination of the usual rightaugled flexion of the legs with this form of cushioning would do away with the necessity for any dangerous pressure applied to the shoulders or iliac crests. I am in contact with manufacturers, in order to obtain a rubber mattress of the suggested design. T. B. FITZGERALD
University College Hospital, London, W.C.1.
Obstetric Registrar.
MEDICAL TEACHING IN BAGDAD
SIR,—Your
government’s
note last week (p. 284) refers to the Iraqi desire to enlist British doctors to teach
in the Royal College of Medicine in Bagdad. As I held the chair of physiology there for five years before the I war a word on my experience may be of interest. in the in both entirely enjoyed my stay Iraq, professional and the social aspects, and it was with regret that I relinquished the appointment for family reasons. The opportunities for research are unrivalled and the college authorities and Directorate of Health gave me every facility I needed for investigation. Moreover the research problems there in parasitology, infectious diseases, and nutrition (to name only three fields) urgently demand solution and one has a splendid chance to contribute to the struggle against human suffering. I would have no hesitation in recommending any doctor to apply for one of these posts if he accepted one condition. That is that he would be prepared to develop to the full social contacts with the Iraqi people. If he only wishes to mix with other Britons he had better stay at home. Both my wife and I found our many Iraqi friends pleasant hosts and welcome guests. High government officials assured me that they considered British participation in Iraqi social life to be an important contribution to the development of the country. Personally I found it well worth while. for sport are good and the climate The is not so trying as some people make out, though the winter is rather cold. W. P. KENNEDY. London.
opportunities
VITAMIN
B12 AND THYROID FUNCTION
SiR,-The effect of liver extracts on thyroid function is obscure. Wintrobe has suggested that they may have a thyrogenic action because of the not-infrequent development of hyperthyroidism in patients receiving liver therapy for pernicious anaemia. On the other hand, it has been shown2 that some of the toxic effects of thyroid extract in rats can be prevented by feeding with liver, and it is also stated that patients receiving thyroid therapy for hypothyroidism require larger doses of thyroid extract if liver therapy for pernicious anaemia is initiated.3 It is, moreover, suggested that there is in liver extract a component, probably vitamin B 12. itself, which has a specific antithyroid action.3 If the latter statement were to be substantiated, it would obviously be of prime importance, not only to those interested in the possibility of a new drug for the treatment of hyperthyroidism, but also to patients with addisonian anaemia, to whom high doses of vitamin B12 will
undoubtedly
be
given
now
that it is
cheap
and
freely
available, and in whom symptoms of hypothyroidism occur. Such an effect of prolonged administration of vitamin B12 has not, as far as we know, been reported yet by workers in this country or in the U.S.A. We felt, therefore, that it would be of interest to assay the possible antithyroid activity of vitamin B12 by the method of Stanley and Astwood,4 using radioactive iodine
might
1. Wintrobe, M. M. Clinical Hæmatology. London, 1946; p. 356. 2. Ershoff, B. H. Proc. Soc. exp. Biol., N.Y. 1947, 64, 500. 3. Annotation, Amer. J. Digest. Dis. 1949, 16, 418. 4. Stanley, M. M., Astwood, E. B. Endocrinology, 1947, 41, 66.
technique recently used by uto assess the antithyroid activity of para-aminobenzoic acid."
-a
Two male patients with normal thyroid function were given 60 (JLg. and 100 ug. respectively of crystalline vitamin B12z (’ Cytamen,’ Glaxo) at a time when iodine accumulation in the thyroid gland was proceeding at a steady rate. The samples were from a batch which had been proved clinically to be active in pernicious anaemia. The administration of the drug did not have, in either patient, the slightest effect on the straight line of the graph which is obtained when the thyroidgland activity is plotted against the square-root of the time. If the drug, in the dosage used, had had any antithyroid activity, an immediate effect on iodine retention in the gland would have been shown by a downward deviation of the graph from the straight line. We have no experience of the effect which would be obtained if a drug with definite thyrogenic properties were assayed by this technique. We should, however, expect that an upward deviation of the curve would occur, corresponding to an increased iodine absorption by the
gland.
We concluded that in a dosage of 100 µg. or less, vitamin B12has no significant effect on thyroid function. E. J. WAYNE Department of Pharmacology and Therapeutics, University of Sheffield, A. G. MACGREGOR and the Sheffield National Centre for H. MILLER. Radiotherapy. THE CHEST PHYSICIAN
SIR,—Young chest physicians like myself will be grateful that Dr. Toussaint has exposed, in his letter last week, the dilemma in which we now find ourselves. Should we clear out of the specialty if it is to have no decent future ? I became interested in tuberculosis when I began to discover what a wide range of unexplored fields of medicine this disease offers. Tuberculosis occupies a not only into many with ramifications unique position, branches of medicine and surgery, but into aspects of
sociology, psychology, business, economics, politics (certainly local politics !), and indeed every aspect of human affairs. I became increasingly fascinated by the possibilities of tuberculosis control and felt impelled to specialise in this branch of medicine. It appeared that no longer were young men like myself to be penalised financially for displaying interest in that one major disease which par excellence is disregarded in teaching hospitals. My interest in tuberculosis is -clinical as well as social ; I do not aspire to an administrative appointment divorced from clinical medicine such as used to be a reason for a young man interesting himself in the disease.
And now what ? Has a mistake been made ? Is tuberculosis after all not to recruit its share of the ablest in my generation ?If we are foolish enough to interest ourselves in this work, must we then accept the consequences of a lower income on account of our strange idiosyncrasy ? Is the degradation of the tuberculosis service to be perpetuated ? The situation is ludicrous. Glasgow has a higher mortality from this disease than Hamburg despite conditions there in the last decade ; while Scandinavia can afford to inquire politely why we do not take steps to prevent a preventable disease. The tragedy of all this is not the personal fate of doctors who happen to be interested in tuberculosis, but the personal fate of the four hundred British men and women who die each week of this disease-which is more preventable than any other great scourge of mankind todav. The taxpayer wants to see his diseases effectively controlled as quickly as possible at minimal expense. Three administrative measures, all supported by those who really understand tuberculosis, could immediately be taken and in ten years would reduce the tuberculosis problem by more than half : (1) recruit the best brains of the profession into the tuberculosis field by offering 5.
Goodwin, J. F., Miller, H., Wayne,
E. J.
Lancet, 1949, ii, 1211.
University College Hospital, London, W.C.1.
Obstetric Registrar.
MEDICAL TEACHING IN BAGDAD
SIR,—Your
government’s
note last week (p. 284) refers to the Iraqi desire to enlist British doctors to teach
in the Royal College of Medicine in Bagdad. As I held the chair of physiology there for five years before the I war a word on my experience may be of interest. in the in both entirely enjoyed my stay Iraq, professional and the social aspects, and it was with regret that I relinquished the appointment for family reasons. The opportunities for research are unrivalled and the college authorities and Directorate of Health gave me every facility I needed for investigation. Moreover the research problems there in parasitology, infectious diseases, and nutrition (to name only three fields) urgently demand solution and one has a splendid chance to contribute to the struggle against human suffering. I would have no hesitation in recommending any doctor to apply for one of these posts if he accepted one condition. That is that he would be prepared to develop to the full social contacts with the Iraqi people. If he only wishes to mix with other Britons he had better stay at home. Both my wife and I found our many Iraqi friends pleasant hosts and welcome guests. High government officials assured me that they considered British participation in Iraqi social life to be an important contribution to the development of the country. Personally I found it well worth while. for sport are good and the climate The is not so trying as some people make out, though the winter is rather cold. W. P. KENNEDY. London.
opportunities
VITAMIN
B12 AND THYROID FUNCTION
SiR,-The effect of liver extracts on thyroid function is obscure. Wintrobe has suggested that they may have a thyrogenic action because of the not-infrequent development of hyperthyroidism in patients receiving liver therapy for pernicious anaemia. On the other hand, it has been shown2 that some of the toxic effects of thyroid extract in rats can be prevented by feeding with liver, and it is also stated that patients receiving thyroid therapy for hypothyroidism require larger doses of thyroid extract if liver therapy for pernicious anaemia is initiated.3 It is, moreover, suggested that there is in liver extract a component, probably vitamin B 12. itself, which has a specific antithyroid action.3 If the latter statement were to be substantiated, it would obviously be of prime importance, not only to those interested in the possibility of a new drug for the treatment of hyperthyroidism, but also to patients with addisonian anaemia, to whom high doses of vitamin B12 will
undoubtedly
be
given
now
that it is
cheap
and
freely
available, and in whom symptoms of hypothyroidism occur. Such an effect of prolonged administration of vitamin B12 has not, as far as we know, been reported yet by workers in this country or in the U.S.A. We felt, therefore, that it would be of interest to assay the possible antithyroid activity of vitamin B12 by the method of Stanley and Astwood,4 using radioactive iodine
might
1. Wintrobe, M. M. Clinical Hæmatology. London, 1946; p. 356. 2. Ershoff, B. H. Proc. Soc. exp. Biol., N.Y. 1947, 64, 500. 3. Annotation, Amer. J. Digest. Dis. 1949, 16, 418. 4. Stanley, M. M., Astwood, E. B. Endocrinology, 1947, 41, 66.
technique recently used by uto assess the antithyroid activity of para-aminobenzoic acid."
-a
Two male patients with normal thyroid function were given 60 (JLg. and 100 ug. respectively of crystalline vitamin B12z (’ Cytamen,’ Glaxo) at a time when iodine accumulation in the thyroid gland was proceeding at a steady rate. The samples were from a batch which had been proved clinically to be active in pernicious anaemia. The administration of the drug did not have, in either patient, the slightest effect on the straight line of the graph which is obtained when the thyroidgland activity is plotted against the square-root of the time. If the drug, in the dosage used, had had any antithyroid activity, an immediate effect on iodine retention in the gland would have been shown by a downward deviation of the graph from the straight line. We have no experience of the effect which would be obtained if a drug with definite thyrogenic properties were assayed by this technique. We should, however, expect that an upward deviation of the curve would occur, corresponding to an increased iodine absorption by the
gland.
We concluded that in a dosage of 100 µg. or less, vitamin B12has no significant effect on thyroid function. E. J. WAYNE Department of Pharmacology and Therapeutics, University of Sheffield, A. G. MACGREGOR and the Sheffield National Centre for H. MILLER. Radiotherapy. THE CHEST PHYSICIAN
SIR,—Young chest physicians like myself will be grateful that Dr. Toussaint has exposed, in his letter last week, the dilemma in which we now find ourselves. Should we clear out of the specialty if it is to have no decent future ? I became interested in tuberculosis when I began to discover what a wide range of unexplored fields of medicine this disease offers. Tuberculosis occupies a not only into many with ramifications unique position, branches of medicine and surgery, but into aspects of
sociology, psychology, business, economics, politics (certainly local politics !), and indeed every aspect of human affairs. I became increasingly fascinated by the possibilities of tuberculosis control and felt impelled to specialise in this branch of medicine. It appeared that no longer were young men like myself to be penalised financially for displaying interest in that one major disease which par excellence is disregarded in teaching hospitals. My interest in tuberculosis is -clinical as well as social ; I do not aspire to an administrative appointment divorced from clinical medicine such as used to be a reason for a young man interesting himself in the disease.
And now what ? Has a mistake been made ? Is tuberculosis after all not to recruit its share of the ablest in my generation ?If we are foolish enough to interest ourselves in this work, must we then accept the consequences of a lower income on account of our strange idiosyncrasy ? Is the degradation of the tuberculosis service to be perpetuated ? The situation is ludicrous. Glasgow has a higher mortality from this disease than Hamburg despite conditions there in the last decade ; while Scandinavia can afford to inquire politely why we do not take steps to prevent a preventable disease. The tragedy of all this is not the personal fate of doctors who happen to be interested in tuberculosis, but the personal fate of the four hundred British men and women who die each week of this disease-which is more preventable than any other great scourge of mankind todav. The taxpayer wants to see his diseases effectively controlled as quickly as possible at minimal expense. Three administrative measures, all supported by those who really understand tuberculosis, could immediately be taken and in ten years would reduce the tuberculosis problem by more than half : (1) recruit the best brains of the profession into the tuberculosis field by offering 5.
Goodwin, J. F., Miller, H., Wayne,
E. J.
Lancet, 1949, ii, 1211.