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NOMOGRAM FOR DERIVATION OF RENAL THRESHOLD PHOSPHATE CONCENTRATION
309
4. 5. 6. 7.
8. 9. 10. 11.
Born, G. V. R. Nature, 1962, 194, 927. Hardisty, R. M., Hutton, R. A., Montgomery, D., Rickard, S., Trebilcock, H. Br. J. Hœmat. 1970, 19, 307. Kwaan, H. C., Colwell, J. A., Cruz, S., Suwanwela, N., Dobbie, J. G. J. Lab. clin. Med. 1972, 80, 236. O’Brien, J. R., Heywood, J. B., Heady, J. A. Thromb. Diath. hœmorrh. 1966, 16, 752. Danta, G. ibid. 1970, 23, 159. Mettler, L., Meseck-Selchow, B. ibid. 1972, 28, 213. Bryant, S. H., Morales-Aguiler, A. J. Physiol., Lond. 1971, 219, 367. Lipicky, R. J., Bryant, S. H. J. gen. Physiol. 1966, 50, 89.
fail
Methods and Devices NOMOGRAM FOR DERIVATION OF RENAL THRESHOLD PHOSPHATE CONCENTRATION
R. J. WALTON
O. L. M.
BIJVOET
Department of Endocrinology and Metabolism, University Hospital, Leiden, Netherlands THE kidneys play an important part in the regulation of plasma-phosphate concentration [pro4]. Clinical assessthis function aim to discriminate between the three factors which determine [P04]: (1) the net inflow of phosphate into the extracellular space from bone, gut, andsoft tissues (in steady-state conditions, this inflow is equal to the urinary-excretion rate of phosphate), (2) the tubular reabsorption of phosphate, which determines the average [PO4] at which phosphate inflow equals urinary phosphateexcretion rate, and (3) glomerular filtration-rate (G.F.R.), which determines the change in [PO4] produced by a change in phosphate inflow. Indices of renal tubular reabsorption of phosphate such as phosphate clearance (Cpo4), phosphate/creatinine clearance ratio (CPO4/Ccr), fractional tubular reabsorption of phosphate (T.R.P.), phosphate excretion index, and index of phosphate excretion ments of
Lipicky, R. J., Bryant, S. H. Trans. Am. Neurol. Ass. 1971, 96, 34. Lipicky, R. J., Bryant, S. H., Salmon, J. H. J. clin. Invest. 1971, 50, 2091. 14. Seiler, D. Experientia, 1971, 27, 1170. 15. Roses, A. D., Appel, S. H. Nature, 1974, 250, 245. 16. Seiler, D., Kuhn, E. Schweiz. med. Wschr. 1970, 100, 1374. 17. Aledort, L. M., Puszkin, S., Puszkin, E., Hanson, J., Katz, A. M. Microvasc. Res. 1973, 6, 246. 18. Booyse, F. M., Guiliani, D., Rafelson, M. E. ibid. p. 244. 19. Born, G. V. R., Mills, D. C. B., Roberts, G. C. K. J. Physiol., Lond. 1967, 191, 43P. 20. Mills, D. C. B., Roberts, G. C. K. ibid. 1967, 193, 443. 12. 13.
discriminate between these three factors. The activity of renal tubular reabsorption of phosphate is best expressed as the renal threshold phosphate concentration (also denoted as TmPO4/G.F.R., the ratio of maximum rate of renal tubular reabsorption of phosphate to G.F.R.), which is independent of G.F.R. and of net inflow of phosphate. Tmpo4/G.F.R. can be measured directly by phosphate infusion procedures,l but these are not suitable for routine clinical use. Bijvoet and Morgan 2 demonstrated that when T.R.P., or its complement Cpo4/Ccr, was plotted against the ratio of TmPO4/G.F.R. to [PO4], the values obtained from 100 phosphate-infusion experiments performed on normal subjects and on patients with parathyroid and thyroid disorders were distributed very narrowly about a curve, which could therefore be used as a nomogram for determining TmP04/G.F.R. without the need for phosphate infusions. However, this nomogram still requires some calculation to convert values of [P04] and T.R.P. to the corresponding value of TmPO4/G.F.R. The purpose of the present communication is to describe an improved nomogram,* based on the data of Bijvoet and Morgan,2 which avoids this calculation and is used as follows. The patient is fasted overnight, and a urine sample (which need not be accurately timed but which should be
*
to
Enlargements (approximately
15 x 15
from 0. L. M. B.
Nomogram for derivation of renal threshold phosphate concentration.
cm.)
may be obtained
310 collected over a reasonably short period, say 1-2 hours) and a blood-sample are obtained. T.R.P. or Cro4/Ccr can then be derived from the expressions:
where Up04=urine phosphate concentration, Ucr=urine creatinine concentration, [P04]=plasma-phosphate, and [Cr]=plasma-creatinine (all expressed in consistent units). The nomogram can then be used to derive Tmpo4/G.F.R. A straight line through the appropriate values of [PO4] and T.R.P. (or Cpo4/Ccr) passes through the corresponding value of Tmp04/G.F.R. TmPO4/G.F.R. and [P04] are expressed in the same units. The scales and units are arbitrary, but the same should be used for both [P04] and Tmpo4/G.F.R. Two scales have been chosen: the 0-0-2-0 scale is suitable for estimating values of TmPO4/G.F.R. close to the normal range expressed in S.I. units (0-80-1-35 mmol/1.), and the 0-0-5-0 scale for values close to the normal range expressed in mass units (2-5-4-2 mg. per 100 ml.). If necessary, the scales for [P04] and TmPO4/G.F.R. can be multiplied or divided by any number (provided that the same number is used for both scales). R. J. W. acknowledges a travel award from the British Council. REFERENCES 1. 2.
Bijvoet, O. L. M. Clin. Sci. 1969, 37, 23. Bijvoet, O. L. M., Morgan, D. B. in Phosphate et métabolisme phosphocalcique (edited by D. J. Hioco); p. 153. Paris, 1971.
system, motor and sensory fibres are shown in association with the wrong side of the central sulcus of the brain. As a former professor of anatomy used to say: " it’s like a car-the motor in front and the smell behind nervous
Cryosurgery in Ophthalmology S. PERCY AMOILS, F.R.C.S., cryosurgical research unit, Natalspruit Hospital, South Africa. London: Pitman. 1975. Pp. 181. £5.
THE use of a freezing-probe to extract cataracts has been the only significant innovation in ophthalmology to derive from Eastern Europe since the war. But it has been of enormous value, and has made this standard operation so free from its major hazards that to many of the older surgeons, who are proud of their dexterity, it seems to have " taken all the fun out of the operation ". Subsequently it was found that the same freezing-probe could coagulate the choroid (so that it will adhere to a detached retina) as readily as the classical diathermy terminal, but with’much less necrosis of the overlying scleral lamellae. And a further but limited use of the cryoprobe has been found in coagulation of the ciliary body (for intractable glaucoma), cornea, iris, lids, and so on. This handy and well-illustrated little book is written by Dr Amoils, to whose expertise we owe the most efficient and widely used cryosurgical machine which bears his name.
The
Psychophysiology
of Mental Illness
MALCOLM LADER, M.D., Institute of Psychiatry, University of London. London: Routledge & Kegan Paul. 1975. Pp. 270. E7.25.
Reviews of Books
Urology
Illustrated
Roy SCOTT, F.R.C.S.E., Royal Infirmary, Glasgow, R. FLETCHER DEANE, F.R.C.S.E., Western Infirmary, Glasgow, and ROBIN CALLANDER, F.F.PH., medical illustration unit, University of Glasgow. Edinburgh: Churchill Livingstone. 1975. Pp. 483. E4.75.
THE profusion of big line drawings and the uniformly large type leave little room in this book for the text. It is greatly to the authors’ credit that with their condensed style they have covered the whole field of urology, without even leaving out such museum pieces as the " penile horn ". Nurses, medical students, and doctors up to fellowship level will find plenty of up-to-date information here, presented in an easily read form. The sections on basic sciences, clinical examination, and investigation are well done, and
the various forms of treatment are discussed in such a well-balanced manner that few criticisms spring to mind. The paragraph on catheterisation, however, makes no mention of pre-treatment of the urethra with an antiseptic/ anaesthetic gel, and it is surely begging the question to recommend a " suitable sized catheter ". The section on the neurogenic bladder gives the unfortunate impression that bladder-neck resection or division of the external sphincter produces continuous incontinence from an empty bladder, which is very far from the truth. The drawings are excellent, though under post-prostatectomy incontinence a rectus sheath sling is shown passing under the penile urethra, while the text describes a bladder-neck position and throws in a quite inappropriate reference to the gracilis muscle. Again, in many of the illustrations of the central
THERE are now several textbooks on the psychophysiology of normal subjects, but this is the first one to be addressed specifically to mentally ill patients. Even with this restriction the field is still large, but Malcolm Lader is a knowledgeable and thorough guide. The book starts with a section on techniques, with fairly brief sections on a large number of physiological variables, each one being only long enough to whet, rather than satisfy, the appetite. It might have been better to have been told more about fewer of the indices described. The same is true for the account of psychophysiological concepts which follows: the section on the important concept of arousal is inadequate for a specialist monograph, and ’the very brief piece on sexual arousal contains the strange assertion that the physiological changes accompanying sexual arousal are not indicators of psychological status. The best part of the book consists of separate sections on anxiety, depression, and schizophrenia which provide useful summaries of recent papers in what is now a rapidly expanding area. Despite a bibliography of about 750 papers, the accumulated sum of human knowledge at the end of the book is somewhat disappointing. Nevertheless, postgraduate students will find the book a useful source of references, and it should appeal to both psychiatrists and psychologists.
Radiology of Syndromes HOOSSANG TAYBI, University of California, San Francisco. Chicago: Year Book. London: Lloyd Luke. 1975. Pp. 333. $39.50; E21.75.
Taybi has assembled a massive 541 syndromes, abridged their clinical and radiological manifestations, and presented them in an order designed for easy reference. Also provided are an alphabetical list and synonyms. For the busy radiologist this book may have a place as a dictionary of syndromes, but it adds very little to the radiologist’s or to the clinician’s radiological armamentarium. It is grossly overpriced. Dr
4. 5. 6. 7.
8. 9. 10. 11.
Born, G. V. R. Nature, 1962, 194, 927. Hardisty, R. M., Hutton, R. A., Montgomery, D., Rickard, S., Trebilcock, H. Br. J. Hœmat. 1970, 19, 307. Kwaan, H. C., Colwell, J. A., Cruz, S., Suwanwela, N., Dobbie, J. G. J. Lab. clin. Med. 1972, 80, 236. O’Brien, J. R., Heywood, J. B., Heady, J. A. Thromb. Diath. hœmorrh. 1966, 16, 752. Danta, G. ibid. 1970, 23, 159. Mettler, L., Meseck-Selchow, B. ibid. 1972, 28, 213. Bryant, S. H., Morales-Aguiler, A. J. Physiol., Lond. 1971, 219, 367. Lipicky, R. J., Bryant, S. H. J. gen. Physiol. 1966, 50, 89.
fail
Methods and Devices NOMOGRAM FOR DERIVATION OF RENAL THRESHOLD PHOSPHATE CONCENTRATION
R. J. WALTON
O. L. M.
BIJVOET
Department of Endocrinology and Metabolism, University Hospital, Leiden, Netherlands THE kidneys play an important part in the regulation of plasma-phosphate concentration [pro4]. Clinical assessthis function aim to discriminate between the three factors which determine [P04]: (1) the net inflow of phosphate into the extracellular space from bone, gut, andsoft tissues (in steady-state conditions, this inflow is equal to the urinary-excretion rate of phosphate), (2) the tubular reabsorption of phosphate, which determines the average [PO4] at which phosphate inflow equals urinary phosphateexcretion rate, and (3) glomerular filtration-rate (G.F.R.), which determines the change in [PO4] produced by a change in phosphate inflow. Indices of renal tubular reabsorption of phosphate such as phosphate clearance (Cpo4), phosphate/creatinine clearance ratio (CPO4/Ccr), fractional tubular reabsorption of phosphate (T.R.P.), phosphate excretion index, and index of phosphate excretion ments of
Lipicky, R. J., Bryant, S. H. Trans. Am. Neurol. Ass. 1971, 96, 34. Lipicky, R. J., Bryant, S. H., Salmon, J. H. J. clin. Invest. 1971, 50, 2091. 14. Seiler, D. Experientia, 1971, 27, 1170. 15. Roses, A. D., Appel, S. H. Nature, 1974, 250, 245. 16. Seiler, D., Kuhn, E. Schweiz. med. Wschr. 1970, 100, 1374. 17. Aledort, L. M., Puszkin, S., Puszkin, E., Hanson, J., Katz, A. M. Microvasc. Res. 1973, 6, 246. 18. Booyse, F. M., Guiliani, D., Rafelson, M. E. ibid. p. 244. 19. Born, G. V. R., Mills, D. C. B., Roberts, G. C. K. J. Physiol., Lond. 1967, 191, 43P. 20. Mills, D. C. B., Roberts, G. C. K. ibid. 1967, 193, 443. 12. 13.
discriminate between these three factors. The activity of renal tubular reabsorption of phosphate is best expressed as the renal threshold phosphate concentration (also denoted as TmPO4/G.F.R., the ratio of maximum rate of renal tubular reabsorption of phosphate to G.F.R.), which is independent of G.F.R. and of net inflow of phosphate. Tmpo4/G.F.R. can be measured directly by phosphate infusion procedures,l but these are not suitable for routine clinical use. Bijvoet and Morgan 2 demonstrated that when T.R.P., or its complement Cpo4/Ccr, was plotted against the ratio of TmPO4/G.F.R. to [PO4], the values obtained from 100 phosphate-infusion experiments performed on normal subjects and on patients with parathyroid and thyroid disorders were distributed very narrowly about a curve, which could therefore be used as a nomogram for determining TmP04/G.F.R. without the need for phosphate infusions. However, this nomogram still requires some calculation to convert values of [P04] and T.R.P. to the corresponding value of TmPO4/G.F.R. The purpose of the present communication is to describe an improved nomogram,* based on the data of Bijvoet and Morgan,2 which avoids this calculation and is used as follows. The patient is fasted overnight, and a urine sample (which need not be accurately timed but which should be
*
to
Enlargements (approximately
15 x 15
from 0. L. M. B.
Nomogram for derivation of renal threshold phosphate concentration.
cm.)
may be obtained
310 collected over a reasonably short period, say 1-2 hours) and a blood-sample are obtained. T.R.P. or Cro4/Ccr can then be derived from the expressions:
where Up04=urine phosphate concentration, Ucr=urine creatinine concentration, [P04]=plasma-phosphate, and [Cr]=plasma-creatinine (all expressed in consistent units). The nomogram can then be used to derive Tmpo4/G.F.R. A straight line through the appropriate values of [PO4] and T.R.P. (or Cpo4/Ccr) passes through the corresponding value of Tmp04/G.F.R. TmPO4/G.F.R. and [P04] are expressed in the same units. The scales and units are arbitrary, but the same should be used for both [P04] and Tmpo4/G.F.R. Two scales have been chosen: the 0-0-2-0 scale is suitable for estimating values of TmPO4/G.F.R. close to the normal range expressed in S.I. units (0-80-1-35 mmol/1.), and the 0-0-5-0 scale for values close to the normal range expressed in mass units (2-5-4-2 mg. per 100 ml.). If necessary, the scales for [P04] and TmPO4/G.F.R. can be multiplied or divided by any number (provided that the same number is used for both scales). R. J. W. acknowledges a travel award from the British Council. REFERENCES 1. 2.
Bijvoet, O. L. M. Clin. Sci. 1969, 37, 23. Bijvoet, O. L. M., Morgan, D. B. in Phosphate et métabolisme phosphocalcique (edited by D. J. Hioco); p. 153. Paris, 1971.
system, motor and sensory fibres are shown in association with the wrong side of the central sulcus of the brain. As a former professor of anatomy used to say: " it’s like a car-the motor in front and the smell behind nervous
Cryosurgery in Ophthalmology S. PERCY AMOILS, F.R.C.S., cryosurgical research unit, Natalspruit Hospital, South Africa. London: Pitman. 1975. Pp. 181. £5.
THE use of a freezing-probe to extract cataracts has been the only significant innovation in ophthalmology to derive from Eastern Europe since the war. But it has been of enormous value, and has made this standard operation so free from its major hazards that to many of the older surgeons, who are proud of their dexterity, it seems to have " taken all the fun out of the operation ". Subsequently it was found that the same freezing-probe could coagulate the choroid (so that it will adhere to a detached retina) as readily as the classical diathermy terminal, but with’much less necrosis of the overlying scleral lamellae. And a further but limited use of the cryoprobe has been found in coagulation of the ciliary body (for intractable glaucoma), cornea, iris, lids, and so on. This handy and well-illustrated little book is written by Dr Amoils, to whose expertise we owe the most efficient and widely used cryosurgical machine which bears his name.
The
Psychophysiology
of Mental Illness
MALCOLM LADER, M.D., Institute of Psychiatry, University of London. London: Routledge & Kegan Paul. 1975. Pp. 270. E7.25.
Reviews of Books
Urology
Illustrated
Roy SCOTT, F.R.C.S.E., Royal Infirmary, Glasgow, R. FLETCHER DEANE, F.R.C.S.E., Western Infirmary, Glasgow, and ROBIN CALLANDER, F.F.PH., medical illustration unit, University of Glasgow. Edinburgh: Churchill Livingstone. 1975. Pp. 483. E4.75.
THE profusion of big line drawings and the uniformly large type leave little room in this book for the text. It is greatly to the authors’ credit that with their condensed style they have covered the whole field of urology, without even leaving out such museum pieces as the " penile horn ". Nurses, medical students, and doctors up to fellowship level will find plenty of up-to-date information here, presented in an easily read form. The sections on basic sciences, clinical examination, and investigation are well done, and
the various forms of treatment are discussed in such a well-balanced manner that few criticisms spring to mind. The paragraph on catheterisation, however, makes no mention of pre-treatment of the urethra with an antiseptic/ anaesthetic gel, and it is surely begging the question to recommend a " suitable sized catheter ". The section on the neurogenic bladder gives the unfortunate impression that bladder-neck resection or division of the external sphincter produces continuous incontinence from an empty bladder, which is very far from the truth. The drawings are excellent, though under post-prostatectomy incontinence a rectus sheath sling is shown passing under the penile urethra, while the text describes a bladder-neck position and throws in a quite inappropriate reference to the gracilis muscle. Again, in many of the illustrations of the central
THERE are now several textbooks on the psychophysiology of normal subjects, but this is the first one to be addressed specifically to mentally ill patients. Even with this restriction the field is still large, but Malcolm Lader is a knowledgeable and thorough guide. The book starts with a section on techniques, with fairly brief sections on a large number of physiological variables, each one being only long enough to whet, rather than satisfy, the appetite. It might have been better to have been told more about fewer of the indices described. The same is true for the account of psychophysiological concepts which follows: the section on the important concept of arousal is inadequate for a specialist monograph, and ’the very brief piece on sexual arousal contains the strange assertion that the physiological changes accompanying sexual arousal are not indicators of psychological status. The best part of the book consists of separate sections on anxiety, depression, and schizophrenia which provide useful summaries of recent papers in what is now a rapidly expanding area. Despite a bibliography of about 750 papers, the accumulated sum of human knowledge at the end of the book is somewhat disappointing. Nevertheless, postgraduate students will find the book a useful source of references, and it should appeal to both psychiatrists and psychologists.
Radiology of Syndromes HOOSSANG TAYBI, University of California, San Francisco. Chicago: Year Book. London: Lloyd Luke. 1975. Pp. 333. $39.50; E21.75.
Taybi has assembled a massive 541 syndromes, abridged their clinical and radiological manifestations, and presented them in an order designed for easy reference. Also provided are an alphabetical list and synonyms. For the busy radiologist this book may have a place as a dictionary of syndromes, but it adds very little to the radiologist’s or to the clinician’s radiological armamentarium. It is grossly overpriced. Dr