- Email: [email protected]
VISUAL SCREENER FOR ETHAMBUTOL TOXICITY
493 wood.4
When the
same H.G.H.
standard solution
was
used
(I.C.R.F.-6), the methods gave similar results (fig. 3). The growth-hormone assay described here was carried out with a radioactive antibody of relatively low specific activity, but was adequate for the measurement of physiological levels of plasma-H.G.H. The unknown H.G.H. was made radioactive by combination with 1251-A.B. to give an approximate specific activity of 4 mC per mg. H.G.H. This indicates that the antibodies have a specific activity of no greater than 1 mC per mg.
Fig. 3-Human plasma samples assayed for H.G.H. content by the immunoradiometric method and the radioimmunoassay method of Hunter and Greenwood.’
made from the subsequent use of the labelled antibodies in an antigen assay. At least 84% of the protein-bound radioactivity was capable of binding specifically to the H.G.H.-ImAd. Immunoradiometric Assay 50 fl.1. of the labelled antibody preparation (1-A.B.) (2-6-26-0 nC) was incubated with 50 1. of an unknown or standard solution of H.G.H. All solutions were made up in 0- 1-M barbiturate buffer pH 8-0, containing (per ml.) 1 mg. bovine serum-albumin, 10 fl.g. non-immune guineapig immunoglobulin, 10 mg. sodium chloride, and 0-1mg. sodium azide (N.I.G.P. buffer). When human plasma was to be assayed at half dilution, the standardgrowth-hormone solutions were also diluted with an equal volume of non-immune guineapig plasma. This was mainly in order that the two solutions should react identically with the Triton ’-toluene liquid scintillation fluid. After incubation at 4°C for 2 days, 10 jjg. of freshly washed H.G.H.-ImAd in 100 1. N.I.G.P. buffer was added and the suspension gently mixed on an angled turntable at room temperature for 50 minutes. At the end of this time, 1-7 ml. of N.I.G.P. buffer (previously diluted to a half with distilled water) was added, and after a brief mix, the supernatant was separated by centrifugation (1500 g) for 10 minutes at room temperature, and sampled for the assay of radioactivity. RESULTS
The concentration of added H.G.H. and the radioactivity in the supernatant were linearly related (fig. 1), until 40% of the radioactivity bound to the H.G.H.-ImAd in the absence of added H.G.H. was present in the supernatant. 81 % of the total radioactivity was bound in the absence of added H.G.H. Successive dilution of plasma from a patient with acromegaly caused a parallel reduction in the apparent H.G.H. content (fig. 2). Six human plasma samples were assayed using (a) the immunoradiometric assay, and (b) the method of Hunter and Green-
Fig. 2-Assay of the H.G.H. concentration in plasma from a patient with acromegaly.
a
and an iodine content of one atom per molecule or less. The linear relationship between added H.G.H. and supernatant radioactivity amounted to 40% of the radioactivity bound to the H.G.H.-ImAd in the absence of added H.G.H. The extent of this part of the standard " curve " is an important factor governing the precision of the assay: the more extensive the linearity, the greater the per cent change in supernatant radioactivity for a given amount of added H.G.H., provided that in each case the excess of 1251-A.B. is no more than is necessary. We thank Prof. F. G. Young for his interest and encouragement, Dr. Ann Stockell Hartree of this department for H.G.H. (0-9 i.u. per mg.), Dr. J. G. Schofield, department of biochemistry, University of Bristol, for guineapig anti-H.G.H. serum, and Dr. F. C. Greenwood, Imperial Cancer Research Fund, Lincoln’s Inn Fields, London W.C.2, for H.G.H. (I.C.R.F.-6) and for the radioimmunoassay of human plasma growth hormone concentrations. The work was supported by grants from the Elmore Fund and the British Diabetic Association.
L. E. M. MILES M.D.
Department of Biochemistry,
University of Cambridge
Cantab., C. N. HALES
N.Z., PH.D.
M.A., M.B.,
PH.D.
M.R.A.C.P.
Cantab.
VISUAL SCREENER FOR ETHAMBUTOL TOXICITY ETHAMBUTOL has been used in the treatment of tuberculosis resistant to standard drugs since 1961. Ocular toxicity, consisting of axial or periaxial retrobulbar neuritis, has been reported by Leibold.5 The axial type, which happens with high dosage, is characterised by a depression of central acuity, central scotoma, and a reduced ability to see green. The periaxial type has no depressed cone vision, but the peripheral isopters are contracted. Fortunately, these changes seem to be reversible. Dr. W. M. Macleod asked me to produce a simple screening device to enable defects in the peripheral colour fields to be detected in patients on ethambutol. The apparatus (figs. 1 and 2) consists of two pieces of wood joined at one end by a bolt. One piece supports a peep-hole at the bolt end and a white fixation target on the front face of a piece of wood at the other end. The other arm bears another piece of wood with three coloured discs-red, blue, and green. A scale of degrees (not visible in the photographs) is inscribed on one of the arms of the device and the angle is read where the other arm crosses it. 4. Hunter, W. M., Greenwood, F. C. Biochem. J. 1964, 5. Leibold, J. E. Ann. N.Y. Acad. Sci. 1966, 135, 904.
successively diluted Fig. 1-Apparatus.
91, 43.
494 this subject (J. H. Kellgren, J. S. Lawrence, and P. R. J. Burch) emphasised the probable heterogeneity of the disease. If only some of the conditions at present accepted as rheumatoid arthritis are significantly affected by genetic factors, and not others, the discordant findings in different on
Fig. 2-Apparatus in
use.
The patient looks through the peep-hole at the white fixation target with the other arm extended at a right angle. He then brings this arm forwards on the temporal side and then the nasal side and the doctor notes when the three colours are first distinguished. The angles are recorded and provide a check for the future while on treatment. If a defect subsequently develops, the patient is referred to the eye department for central fields to be measured, since the readings recorded on this apparatus are empirical. The examination of colour fields is always a very inaccurate procedure and illumination should be standardised as far as possible. The patient stands with his back to a window, a light source which should be similar on each occasion. The usefulness of the device might be increased by selfilluminated coloured test objects. I thank Dr. W. M. Macleod for
Southampton Eye Hospital, Southampton SO9 4XW
suggesting
Febrile Convulsions J. GORDON MILLICHAP, M.D., M.R.C.P., professor of pediatrics and neurology, Northwestern University medical school, and head, division of neurology and seizure clinic, Children’s Memorial Hospital, Chicago. London: Collier-Macmillan. New York: Macmillan Company. Toronto: Collier-Macmillan Canada Ltd. 1968. Pp. 222. 75s. ;$7.95 ;$8.80 (Canada).
the idea.
FEBRILE convulsions in infants and small children
C. B. WALKER M.A.,
countries would be explained. Differences of opinion concerning the pathogenic importance of the various infective agents isolated from rheumatoid joints were also clearly and sometimes forcefully expressed. The interplay of genetics with resistance to infection, obviously important here, was ably discussed by A. C. Allison. Considerable attention was also given to both rheumatoid factor and the antinuclear factor of systemic lupus. The prognostic value of the former is now fairly generally accepted, and A. G. S. Hill made a strong case for regarding the seropositive and seronegative forms of rheumatoid arthritis as two distinct diseases. All in all, this handsomely produced book is full of information of outstanding interest to all rheumatologists.
M.B.
Cantab.,
F.R.C.S.
Reviews of Books Paediatric Cardiology Editor: HAMISI-I WATSON, T.D., M.D., F.R.C.P.E., M.R.C.P., consultant physician and cardiologist, Dundee Group of Teaching
Hospitals, senior lecturer in clinical cardiology and psediatric cardiology, University of Dundee: London: Lloyd-Luke. 1968. Pp. 996. E13. THIS is a very large volume with an international flavour. Its 39 contributors span the world from the Low Countries to the western seaboard of the United States. Many of them are already famous for their contributions to this subject. The presentation, which is in double columns, and the reproduction of illustrations are very good, as are the bibliographies and the index. The book concentrates on anatomy, embryology, and physiology, and techniques in the diagnosis of the many lesions. The care with which the authors have dealt with these aspects of their subjects contrasts with the lack of information about the surgical mortality-rates for palliative and definitive procedures at various ages or sizes of infants and children. The pharmacology of medical treatment is not consistently represented: varying doses for digitalisation appear in different tables, and not all drugs mentioned are related to age or size. The inevitable respiratory complications of many of these lesions, and their treatment, are not emphasised; and the organisation and management of preoperative and postoperative intensive care on which good surgical results so largely depend also receives less attention than is its due. In other respects this is a comprehensive and valuable work of reference.
Rheumatic Diseases Medical Monographs 3. Editors: J. J. R. DuTHIE and W. R. M. ALExANDER. Edinburgh: University Press. Baltimore : Williams & Wilkins Co. 1968. Pp. 296. 63s.
Pfizer
THIS monograph embodies the proceedings of the third Pfizer International Symposium held in Edinburgh in May, 1967. In view of the present conflict of opinion concerning the importance of genetic factors in the pathogenesis of rheumatoid arthritis, it is notable that all three main speakers
are a
subject of considerable interest, especially as regards aetiology and their relation to epilepsy occurring as the child gets older. Professor Millichap has based this monograph on a detailed study of 110 personally observed patients together with a comprehensive review of other reports. The book includes a valuable account of his experimental work on the production of febrile convulsions in small animals by microwave diathermy. This study will be of real value to anyone who is interested in the clinical and experimental aspects of convulsive disorders.
Functional
Pathology
of the Cervical
Spine
Radiographic Studies of Function and Dysfunction in Congenital Disorders, Cervical Spondylosis and Injuries. L. PENNING, neuroradiologist at the University Hospital, State University, Groningen, The Netherlands.
Excerpta Medica $13.50; E513s.
Amsterdam, New York, and London: 1968. Pp. 196. D.fl. 48.60;
Foundation.
THIS excellent book is written primarily for the specialist radiologist, orthopxdic surgeon, and neurosurgeon. The early chapters on functional radiology, examination, functional anatomy, and congenital disorders are outstanding. The chapter on cervical spondylosis is also good; but not all the author’s advice about treatment will be acceptable to everyone. Despite this and a few other minor criticisms, the volume should find a place in every radiology department and orthopaedic and accident department.
New Editions The Lung and its Disorders in the Newborn Infant: Vol. I in the series Major Problems in Clinical Pediatrics.-2nd ed. By Mary Ellen Avery. London, Philadelphia, and Toronto: W. B. Saunders. 1968. Pp. 285. 81s. ;$9.50 ;$10.30 (Canada). Auscultation of the Heart.-3rd ed. By Richard W. D. Turner. London: E. & S. Livingstone. Baltimore: Williams Wilkins Co. Toronto: Macmillan Company of Canada. 1968.
Edinburgh and &
Pp.
53.
6s. ;$0.95 (Canada).
Bone: Fundamentals of the Physiology of Skeletal Tissue.-3rd ed. By Franklin C. McLean and Marshall R. Urist. London and Chicago: University of Chicago Press. 1968. Pp. 314. 76s.;
$8.50. Gaddum’s Pharmacology.-6th ed. Revised by A. S. V. Burgen and J. F. Mitchell. London, New York, and Toronto: Oxford University Press. 1968. Pp. 234. 35s.
When the
same H.G.H.
standard solution
was
used
(I.C.R.F.-6), the methods gave similar results (fig. 3). The growth-hormone assay described here was carried out with a radioactive antibody of relatively low specific activity, but was adequate for the measurement of physiological levels of plasma-H.G.H. The unknown H.G.H. was made radioactive by combination with 1251-A.B. to give an approximate specific activity of 4 mC per mg. H.G.H. This indicates that the antibodies have a specific activity of no greater than 1 mC per mg.
Fig. 3-Human plasma samples assayed for H.G.H. content by the immunoradiometric method and the radioimmunoassay method of Hunter and Greenwood.’
made from the subsequent use of the labelled antibodies in an antigen assay. At least 84% of the protein-bound radioactivity was capable of binding specifically to the H.G.H.-ImAd. Immunoradiometric Assay 50 fl.1. of the labelled antibody preparation (1-A.B.) (2-6-26-0 nC) was incubated with 50 1. of an unknown or standard solution of H.G.H. All solutions were made up in 0- 1-M barbiturate buffer pH 8-0, containing (per ml.) 1 mg. bovine serum-albumin, 10 fl.g. non-immune guineapig immunoglobulin, 10 mg. sodium chloride, and 0-1mg. sodium azide (N.I.G.P. buffer). When human plasma was to be assayed at half dilution, the standardgrowth-hormone solutions were also diluted with an equal volume of non-immune guineapig plasma. This was mainly in order that the two solutions should react identically with the Triton ’-toluene liquid scintillation fluid. After incubation at 4°C for 2 days, 10 jjg. of freshly washed H.G.H.-ImAd in 100 1. N.I.G.P. buffer was added and the suspension gently mixed on an angled turntable at room temperature for 50 minutes. At the end of this time, 1-7 ml. of N.I.G.P. buffer (previously diluted to a half with distilled water) was added, and after a brief mix, the supernatant was separated by centrifugation (1500 g) for 10 minutes at room temperature, and sampled for the assay of radioactivity. RESULTS
The concentration of added H.G.H. and the radioactivity in the supernatant were linearly related (fig. 1), until 40% of the radioactivity bound to the H.G.H.-ImAd in the absence of added H.G.H. was present in the supernatant. 81 % of the total radioactivity was bound in the absence of added H.G.H. Successive dilution of plasma from a patient with acromegaly caused a parallel reduction in the apparent H.G.H. content (fig. 2). Six human plasma samples were assayed using (a) the immunoradiometric assay, and (b) the method of Hunter and Green-
Fig. 2-Assay of the H.G.H. concentration in plasma from a patient with acromegaly.
a
and an iodine content of one atom per molecule or less. The linear relationship between added H.G.H. and supernatant radioactivity amounted to 40% of the radioactivity bound to the H.G.H.-ImAd in the absence of added H.G.H. The extent of this part of the standard " curve " is an important factor governing the precision of the assay: the more extensive the linearity, the greater the per cent change in supernatant radioactivity for a given amount of added H.G.H., provided that in each case the excess of 1251-A.B. is no more than is necessary. We thank Prof. F. G. Young for his interest and encouragement, Dr. Ann Stockell Hartree of this department for H.G.H. (0-9 i.u. per mg.), Dr. J. G. Schofield, department of biochemistry, University of Bristol, for guineapig anti-H.G.H. serum, and Dr. F. C. Greenwood, Imperial Cancer Research Fund, Lincoln’s Inn Fields, London W.C.2, for H.G.H. (I.C.R.F.-6) and for the radioimmunoassay of human plasma growth hormone concentrations. The work was supported by grants from the Elmore Fund and the British Diabetic Association.
L. E. M. MILES M.D.
Department of Biochemistry,
University of Cambridge
Cantab., C. N. HALES
N.Z., PH.D.
M.A., M.B.,
PH.D.
M.R.A.C.P.
Cantab.
VISUAL SCREENER FOR ETHAMBUTOL TOXICITY ETHAMBUTOL has been used in the treatment of tuberculosis resistant to standard drugs since 1961. Ocular toxicity, consisting of axial or periaxial retrobulbar neuritis, has been reported by Leibold.5 The axial type, which happens with high dosage, is characterised by a depression of central acuity, central scotoma, and a reduced ability to see green. The periaxial type has no depressed cone vision, but the peripheral isopters are contracted. Fortunately, these changes seem to be reversible. Dr. W. M. Macleod asked me to produce a simple screening device to enable defects in the peripheral colour fields to be detected in patients on ethambutol. The apparatus (figs. 1 and 2) consists of two pieces of wood joined at one end by a bolt. One piece supports a peep-hole at the bolt end and a white fixation target on the front face of a piece of wood at the other end. The other arm bears another piece of wood with three coloured discs-red, blue, and green. A scale of degrees (not visible in the photographs) is inscribed on one of the arms of the device and the angle is read where the other arm crosses it. 4. Hunter, W. M., Greenwood, F. C. Biochem. J. 1964, 5. Leibold, J. E. Ann. N.Y. Acad. Sci. 1966, 135, 904.
successively diluted Fig. 1-Apparatus.
91, 43.
494 this subject (J. H. Kellgren, J. S. Lawrence, and P. R. J. Burch) emphasised the probable heterogeneity of the disease. If only some of the conditions at present accepted as rheumatoid arthritis are significantly affected by genetic factors, and not others, the discordant findings in different on
Fig. 2-Apparatus in
use.
The patient looks through the peep-hole at the white fixation target with the other arm extended at a right angle. He then brings this arm forwards on the temporal side and then the nasal side and the doctor notes when the three colours are first distinguished. The angles are recorded and provide a check for the future while on treatment. If a defect subsequently develops, the patient is referred to the eye department for central fields to be measured, since the readings recorded on this apparatus are empirical. The examination of colour fields is always a very inaccurate procedure and illumination should be standardised as far as possible. The patient stands with his back to a window, a light source which should be similar on each occasion. The usefulness of the device might be increased by selfilluminated coloured test objects. I thank Dr. W. M. Macleod for
Southampton Eye Hospital, Southampton SO9 4XW
suggesting
Febrile Convulsions J. GORDON MILLICHAP, M.D., M.R.C.P., professor of pediatrics and neurology, Northwestern University medical school, and head, division of neurology and seizure clinic, Children’s Memorial Hospital, Chicago. London: Collier-Macmillan. New York: Macmillan Company. Toronto: Collier-Macmillan Canada Ltd. 1968. Pp. 222. 75s. ;$7.95 ;$8.80 (Canada).
the idea.
FEBRILE convulsions in infants and small children
C. B. WALKER M.A.,
countries would be explained. Differences of opinion concerning the pathogenic importance of the various infective agents isolated from rheumatoid joints were also clearly and sometimes forcefully expressed. The interplay of genetics with resistance to infection, obviously important here, was ably discussed by A. C. Allison. Considerable attention was also given to both rheumatoid factor and the antinuclear factor of systemic lupus. The prognostic value of the former is now fairly generally accepted, and A. G. S. Hill made a strong case for regarding the seropositive and seronegative forms of rheumatoid arthritis as two distinct diseases. All in all, this handsomely produced book is full of information of outstanding interest to all rheumatologists.
M.B.
Cantab.,
F.R.C.S.
Reviews of Books Paediatric Cardiology Editor: HAMISI-I WATSON, T.D., M.D., F.R.C.P.E., M.R.C.P., consultant physician and cardiologist, Dundee Group of Teaching
Hospitals, senior lecturer in clinical cardiology and psediatric cardiology, University of Dundee: London: Lloyd-Luke. 1968. Pp. 996. E13. THIS is a very large volume with an international flavour. Its 39 contributors span the world from the Low Countries to the western seaboard of the United States. Many of them are already famous for their contributions to this subject. The presentation, which is in double columns, and the reproduction of illustrations are very good, as are the bibliographies and the index. The book concentrates on anatomy, embryology, and physiology, and techniques in the diagnosis of the many lesions. The care with which the authors have dealt with these aspects of their subjects contrasts with the lack of information about the surgical mortality-rates for palliative and definitive procedures at various ages or sizes of infants and children. The pharmacology of medical treatment is not consistently represented: varying doses for digitalisation appear in different tables, and not all drugs mentioned are related to age or size. The inevitable respiratory complications of many of these lesions, and their treatment, are not emphasised; and the organisation and management of preoperative and postoperative intensive care on which good surgical results so largely depend also receives less attention than is its due. In other respects this is a comprehensive and valuable work of reference.
Rheumatic Diseases Medical Monographs 3. Editors: J. J. R. DuTHIE and W. R. M. ALExANDER. Edinburgh: University Press. Baltimore : Williams & Wilkins Co. 1968. Pp. 296. 63s.
Pfizer
THIS monograph embodies the proceedings of the third Pfizer International Symposium held in Edinburgh in May, 1967. In view of the present conflict of opinion concerning the importance of genetic factors in the pathogenesis of rheumatoid arthritis, it is notable that all three main speakers
are a
subject of considerable interest, especially as regards aetiology and their relation to epilepsy occurring as the child gets older. Professor Millichap has based this monograph on a detailed study of 110 personally observed patients together with a comprehensive review of other reports. The book includes a valuable account of his experimental work on the production of febrile convulsions in small animals by microwave diathermy. This study will be of real value to anyone who is interested in the clinical and experimental aspects of convulsive disorders.
Functional
Pathology
of the Cervical
Spine
Radiographic Studies of Function and Dysfunction in Congenital Disorders, Cervical Spondylosis and Injuries. L. PENNING, neuroradiologist at the University Hospital, State University, Groningen, The Netherlands.
Excerpta Medica $13.50; E513s.
Amsterdam, New York, and London: 1968. Pp. 196. D.fl. 48.60;
Foundation.
THIS excellent book is written primarily for the specialist radiologist, orthopxdic surgeon, and neurosurgeon. The early chapters on functional radiology, examination, functional anatomy, and congenital disorders are outstanding. The chapter on cervical spondylosis is also good; but not all the author’s advice about treatment will be acceptable to everyone. Despite this and a few other minor criticisms, the volume should find a place in every radiology department and orthopaedic and accident department.
New Editions The Lung and its Disorders in the Newborn Infant: Vol. I in the series Major Problems in Clinical Pediatrics.-2nd ed. By Mary Ellen Avery. London, Philadelphia, and Toronto: W. B. Saunders. 1968. Pp. 285. 81s. ;$9.50 ;$10.30 (Canada). Auscultation of the Heart.-3rd ed. By Richard W. D. Turner. London: E. & S. Livingstone. Baltimore: Williams Wilkins Co. Toronto: Macmillan Company of Canada. 1968.
Edinburgh and &
Pp.
53.
6s. ;$0.95 (Canada).
Bone: Fundamentals of the Physiology of Skeletal Tissue.-3rd ed. By Franklin C. McLean and Marshall R. Urist. London and Chicago: University of Chicago Press. 1968. Pp. 314. 76s.;
$8.50. Gaddum’s Pharmacology.-6th ed. Revised by A. S. V. Burgen and J. F. Mitchell. London, New York, and Toronto: Oxford University Press. 1968. Pp. 234. 35s.