1190 medium and long-term objectives can be stated, practical methods are available which make good sense in themselves,44 and there is something like a national consensus in favour. What health workers could now be advocating is not merely the indexing of child benefit but its progressive increase. Figures for 1976-77 show that attendance at day nursery, nursery school, and so on for the under-fives ranges from 40% in the professional and managerial classes to 29% in social classes iv and v;l levelling up of the latter figure would make a splendid start for the new Government. London School of Hygiene and London WC1E7HT
Tropical Medicine,
J. N. MORRIS P. O. D. PHAROAH
MANIPULATION FOR BACK PAIN
commentary (April 28) on the report of the group chaired by Prof. A. L. Cochrane makes sad There is indeed "profound and widespread dissatisfaction with the situation facing back-pain sufferers". The only change in the ten years since the industrial survey unit of the Arthritis and Rheumatism Council reported that what is commonly called "rheumatism" is caused by pain in the back, has been a steady increase in the incidence of back d:sorders with no positive action to deal with this major problem. The Back Pain Association has tried to get support fcr research. The British Association of Manipulative Medicint was set up in 1963 by a group of doctors, including orthopxdic surgeons, specialists in physical medicine and occupational health, and general practitioners. This Association, whose membership is restricted to doctors, includes in its objects the initiation of research "to establish the indications for, and results of, manipulation, particularly in conditions where other methods are in current use". The Association is affiliated to the International Federation of Manual Medicine. Manipulation was practised by Hippocrates and has survived in many parts of the world, but not, alas, in British orthodox medicine, despite the advocacy of men such as Sir James Paget, Sir Robert Jones, Sir Walter Mercer, and Timbrell Fisher, and, subsequently, John Mennell and James SIR,-Your
working reading.
Cyriax. Back
pain is responsible for an economic loss to Britain of some ,300 million a year. Those of us who practise manipulative medicine believe that our success-rates could spare the national economy a large part of these losses and alleviate a great deal of human suffering. There is no need (as the Cochrane report suggests) to go outside the medical profession to evaluate manipulative medicine. Studies done so far have had little impact simply because no opportunity has been offered within the N.H.S. to evaluate manipulative medicine properly. In Denmark courses in manipulation are an essential part of the training of rheumatologists. Our Association’s courses and symposia at postgraduate medical centres are always oversubscribed-an indication, perhaps, of the growing awareness amongst doctors that there is something seriously lacking in the teaching within our medical schools and in the practice within our hospitals. Our patients have been aware of this gap for many years. The suggestion that "on-the-spot treatment available at work places might prevent many short spells of sickness absence" is recognised already in industry-for example, the largest oil group in Britain has made manipulative medicine available to its staff for several years now. A. MAXWELL ROBERTSON, 62 Wimpole Street, President, British Association of Manipulative London W1
Medicine
4. Morris, J. N. Bull. N.Y. Acad. Med. 1975, 51, 62. 5. Office of Population Censuses and Surveys. The General Household 1977. H. M. Stationery Office, 1979.
Survey
COMMERCIAL RADIOIMMUNOASSAY FOR FREE THYROXINE
SIR,-Correspondence in your issue of May 5 (p. 980) relating to apparent discrepancies between estimates of the freethyroxine index (FT4 index) and serum-free-thyroxine (fat4) in patients with normal concentrations of thyroxine-binding globulin (T.B.G.) has highlighted the methodological doubts that continue to centre on techniques of measurement of free thyroid hormones. Several workers (e.g., Boss et aU) have questioned results obtained with the commercial kit (Corning Medicalz) for FT4 assay. This widely used kit relies on the use of solid-supported antibody contained in two complementary assay tubes. In one tube part of the test serum sample is introduced, together with labelled thyroxine (T 4): after incubation, the radioactivity bound to antibody is counted and designated "count A". In the second tube a second part of the serum sample is incubated together with labelled T and a protein-blocker: the blocker releases endogenous T from protein-binding sites with the consequence that the antibody-bound activity in this tube (designated "count B") reflects the total concentration of T4 in the sample. The manufacturers propose A/B as an indicator of FT concentration in the test sample. A/B is plotted against FT in a set of standards provided, and the FT4 value of the test sample is read from this curve. However, A/B depends not solely on the free hormone concentration in the sample but also, inter alia, on the concentrations of thyroxine-binding proteins and/or their binding constants. More satisfactory, being less susceptible to these effects, would be the expression:
Bo represents the count in a "standard" tube (not currently provided by the manufacturers) containing zero thyroxine. More satisfactory still is the response "metameter":
where
where T represents the "total" activity initially placed in the second (B) tube (provided such activity substantially comprises pure labelled thyroxine). A third possibility is the variable:
where tT4 is the total thyroxine in the serum sample: this can be calculated from the raw data, as described by the manufacturers.
The effect of relying on A/B, as currently recommended by Corning, is artefactually to lower the calculated T value in samples containing raised concentrations of (for example) T.B.G. (or those in which the equilibrium constant of T.B.G. is increased) , and vice versa. Not surprisingly, Boss et al. have reported’ falling FT values (often to levels substantially below normal) with increasing time of gestation in a study on pregin which this kit was used. Discussions at an international symposium on free thyroid hormones, held in Venice last year, highlighted apparently high FT4 values in T.B.G.-deficient subjects. Re-calculation of the data obtained in such studies, as discussed above, profoundly modifies these conclusions (M. Boss, personal communication). Your May S correspondents refer to the "dialysis method" for the measurement of free T4 and imply that this method is a standard technique possessing the status of a reference
nant women
1. Boss, M., Diahanbakheh, O., Kingstone, D. Br. med. J. 1978, ii, 1496. 2. Odstrchel, G., Herte, W., Ward, F. B., Travis, K., Lindner, R. E., Mason, R. D. in Radioimmunoassay and Related Procedures in Medicine; vol. 11.
Vienna, 1978.
Tropical Medicine,
J. N. MORRIS P. O. D. PHAROAH
MANIPULATION FOR BACK PAIN
commentary (April 28) on the report of the group chaired by Prof. A. L. Cochrane makes sad There is indeed "profound and widespread dissatisfaction with the situation facing back-pain sufferers". The only change in the ten years since the industrial survey unit of the Arthritis and Rheumatism Council reported that what is commonly called "rheumatism" is caused by pain in the back, has been a steady increase in the incidence of back d:sorders with no positive action to deal with this major problem. The Back Pain Association has tried to get support fcr research. The British Association of Manipulative Medicint was set up in 1963 by a group of doctors, including orthopxdic surgeons, specialists in physical medicine and occupational health, and general practitioners. This Association, whose membership is restricted to doctors, includes in its objects the initiation of research "to establish the indications for, and results of, manipulation, particularly in conditions where other methods are in current use". The Association is affiliated to the International Federation of Manual Medicine. Manipulation was practised by Hippocrates and has survived in many parts of the world, but not, alas, in British orthodox medicine, despite the advocacy of men such as Sir James Paget, Sir Robert Jones, Sir Walter Mercer, and Timbrell Fisher, and, subsequently, John Mennell and James SIR,-Your
working reading.
Cyriax. Back
pain is responsible for an economic loss to Britain of some ,300 million a year. Those of us who practise manipulative medicine believe that our success-rates could spare the national economy a large part of these losses and alleviate a great deal of human suffering. There is no need (as the Cochrane report suggests) to go outside the medical profession to evaluate manipulative medicine. Studies done so far have had little impact simply because no opportunity has been offered within the N.H.S. to evaluate manipulative medicine properly. In Denmark courses in manipulation are an essential part of the training of rheumatologists. Our Association’s courses and symposia at postgraduate medical centres are always oversubscribed-an indication, perhaps, of the growing awareness amongst doctors that there is something seriously lacking in the teaching within our medical schools and in the practice within our hospitals. Our patients have been aware of this gap for many years. The suggestion that "on-the-spot treatment available at work places might prevent many short spells of sickness absence" is recognised already in industry-for example, the largest oil group in Britain has made manipulative medicine available to its staff for several years now. A. MAXWELL ROBERTSON, 62 Wimpole Street, President, British Association of Manipulative London W1
Medicine
4. Morris, J. N. Bull. N.Y. Acad. Med. 1975, 51, 62. 5. Office of Population Censuses and Surveys. The General Household 1977. H. M. Stationery Office, 1979.
Survey
COMMERCIAL RADIOIMMUNOASSAY FOR FREE THYROXINE
SIR,-Correspondence in your issue of May 5 (p. 980) relating to apparent discrepancies between estimates of the freethyroxine index (FT4 index) and serum-free-thyroxine (fat4) in patients with normal concentrations of thyroxine-binding globulin (T.B.G.) has highlighted the methodological doubts that continue to centre on techniques of measurement of free thyroid hormones. Several workers (e.g., Boss et aU) have questioned results obtained with the commercial kit (Corning Medicalz) for FT4 assay. This widely used kit relies on the use of solid-supported antibody contained in two complementary assay tubes. In one tube part of the test serum sample is introduced, together with labelled thyroxine (T 4): after incubation, the radioactivity bound to antibody is counted and designated "count A". In the second tube a second part of the serum sample is incubated together with labelled T and a protein-blocker: the blocker releases endogenous T from protein-binding sites with the consequence that the antibody-bound activity in this tube (designated "count B") reflects the total concentration of T4 in the sample. The manufacturers propose A/B as an indicator of FT concentration in the test sample. A/B is plotted against FT in a set of standards provided, and the FT4 value of the test sample is read from this curve. However, A/B depends not solely on the free hormone concentration in the sample but also, inter alia, on the concentrations of thyroxine-binding proteins and/or their binding constants. More satisfactory, being less susceptible to these effects, would be the expression:
Bo represents the count in a "standard" tube (not currently provided by the manufacturers) containing zero thyroxine. More satisfactory still is the response "metameter":
where
where T represents the "total" activity initially placed in the second (B) tube (provided such activity substantially comprises pure labelled thyroxine). A third possibility is the variable:
where tT4 is the total thyroxine in the serum sample: this can be calculated from the raw data, as described by the manufacturers.
The effect of relying on A/B, as currently recommended by Corning, is artefactually to lower the calculated T value in samples containing raised concentrations of (for example) T.B.G. (or those in which the equilibrium constant of T.B.G. is increased) , and vice versa. Not surprisingly, Boss et al. have reported’ falling FT values (often to levels substantially below normal) with increasing time of gestation in a study on pregin which this kit was used. Discussions at an international symposium on free thyroid hormones, held in Venice last year, highlighted apparently high FT4 values in T.B.G.-deficient subjects. Re-calculation of the data obtained in such studies, as discussed above, profoundly modifies these conclusions (M. Boss, personal communication). Your May S correspondents refer to the "dialysis method" for the measurement of free T4 and imply that this method is a standard technique possessing the status of a reference
nant women
1. Boss, M., Diahanbakheh, O., Kingstone, D. Br. med. J. 1978, ii, 1496. 2. Odstrchel, G., Herte, W., Ward, F. B., Travis, K., Lindner, R. E., Mason, R. D. in Radioimmunoassay and Related Procedures in Medicine; vol. 11.
Vienna, 1978.
