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TELEVISION IN THE MEDICAL SCHOOL
1102
in amounts much greater than are and replacement of lamellar by woven bone ",10 rickets. As in hypo- Patients of this strictly defined group consitute a small nutritional required vitamin-D-resistant rickets, the need minority of all cases of azotaemic osteodystrophy: the phosphatoemic for large doses of vitamin D involves the hazard of over- bony changes are indistinguishable from those of dosage and hypercalcaemic intoxication. The individual primary hyperparathyroidism,16 the parathyroid glands patient may apparently have an unpredictable minimal are usually greatly hyperplastic, the plasma-phosphate dosage requirement, and huge doses (up to 200,000 i.u. is high and the plasma-calcium near normal, and meta[5 mg.] of calciferol daily) may sometimes be given static calcification is especially liable to develop sponwithout producing either clinical benefit or detectable taneously.17 Possibly the parathyroid glands in this metabolic effect.9’3 This particular problem can be syndrome become autonomously hyperfunctional (as solved only by metabolic balance measurements; and, apparently occurred in a case of chronic steatorrhoea although general therapeutic rules can be formulated,8 previously reported by DENT18) in which event large there is much to be said for treating these cases in centres doses of vitamin D may not cure the renal osteitis with resources for making such measurements. fibrosa. But whether the parathyroid glands are autoThe metabolic data from these ursemic patients are nomous or not, treatment with vitamin D would tend of interest in that the external mineral balances mimic to raise further, and dangerously, the already high the state in simple vitamin-D deficiency. In the plasma levels of calcium and phosphate. Consequently, untreated patient the faeces contain approximately the in the exceptional patient with bone changes of this same amount of calcium as is taken in the diet, and type, in whom the renal failure appears not to be rapidly the urinary calcium is negligible; the metabolic response advancing, parathyroidectomy may be indicated before to treatment with vitamin D resembles closely the starting treatment with vitamin D.13 response when nutritional rickets is treated with much Investigation of this fascinating group of disorders smaller doses of the vitamin. In the light of the lead should throw new light on the physiology of vitamin given by Lru and CHU,’ these observations have been D and of the parathyroid glands, especially when taken to suggest that in renal failure some factor inter- simpler techniques for vitamin and hormonal assay feres with the biological activity of vitamin D.89 come to hand. At present, cases investigated in Nothing is yet known of the mechanism of this apparent different centres can be compared only if the histoantagonism; but the curative effect of vitamin D in logical state of the bone is known precisely. Thus it is renal osteodystrophy does not seem to be mediated to be hoped that a carefully defined procedure for bone through change in the CaxP ionic product in the biopsy will be followed by all studying this problem.
each
must
be
to
given
cure
plasma.99
Osteitis fibrosa is present in all
of azotasmic Annotations osteodystrophy, even when the chief abnormality is rickets or osteomalacia, and it is nowadays thought to be caused by secondary hyperparathyroidism."-13 Both TELEVISION IN THE MEDICAL SCHOOL DENT 8 and STANBURY 9 13 have detected radiographic LAST week the Postmaster-General made public his evidence of healing of the characteristic cortical reasons for not acceding to the B.B.C.’s request for erosions 14 of secondary hyperparathyroidism during to operate a limited service of colour television; effective treatment with vitamin D. BALL,15 comparing permission and about the same time the Association for the Study of the histological appearances of bone from uraemic Medical Education (ASME), at its conference at the patients who had died after protracted treatment and London Hospital Medical College, was also hearing, of bone obtained by biopsy before treatment was though with rather different explanations, why some started, has shown that osteitis fibrosa is apparently people feel that colour television in medical teaching and reversible by vitamin-D therapy. Whereas the London research has not yet reached the stage for confident workers8 advocate treatment of renal hyperpara- advance and spending of money. Indeed the conference programme imaginatively arranged by the medical thyroidism with vitamin D, those in Manchester have (its committee of the Scientific Film Association) had almost criticised this as dangerous,12 and have resorted to as much to tell about impediments to the effective use of parathyroidectomy (which is obviously also potentially television in the medical school as about its positive powers. dangerous) before giving vitamin D to these patients.13 But the meeting provided an informative examination of a The difference is largely one of semantics, since the relatively new and complex instrument of teaching and former group rely on radiographic appearances for the research; and AsME is ably fulfilling its purpose in diagnosis of renal hyperparathyroidism, whereas the stimulating thought and debate on this sort of enterprise latter restrict the term azotxmic hyperparathyroidism -where enthusiasm may run as far as funds permit before it has looked very carefully where it is going. Enthusiasm, to cases in which the bone shows no histological evidence of defective mineralisation, the skeletal changes being however, seldom fails to meet scepticism; and, as Dr. John dominated by osteitis fibrosa and extensive remodelling Ellis, the Association’s secretary, related, the proposal to cases
"
Ball, J. in Recent Advances in Pathology (edited by C. V. Harrison). London, 1960. 11. Gilmour, J. R. The Parathyroid Glands and Skeleton in Renal Disease. London, 1947. 12. Stanbury, S. W. Brit. med. Bull. 1957, 13, 57. 13. Stanbury, S. W., Lumb, G. A., Nicholson, W. F. Lancet, 1960, i, 793. 14. Pugh, D. B. Amer. J. Roentgenol. 1951, 66, 577. 15. Ball, J. Personal communication.
10.
hold a conference on television in the medical school had its opponents ("No, I still prefer the personal approach"); 16. 17.
Albright, F., Reifenstein, E. C., Jr. The Parathyroid Glands and Metabolic Bone Disease. London, 1948. Herbert, F. K., Miller, H. G., Richardson, G. O. J. Path. Bact. 1941,
53, 161. 18. Davies, D.
R., Dent, C. E., Willcox, A. Brit. med. J. 1956, ii,
1133.
1103 but if the doubters were many their voices were few last week, and the main message of the meeting was that, despite technical misgivings and questions about details of application, television has a place in the medical school as an extension of the power and range of the teacher-
though never as a dominating technique. Thus, the quality of the teacher mattered more than the mechanism of his teaching, declared Prof. Roger Warwick, the Guy’s anatomist, who has been among the most active examiners of television as a teaching medium in British medical schools (he took a large share in organising the colour demonstration of medical teaching from Alexandra Palace in 1957 ’). Last week a black-andwhite screening of a dissected hand illustrated how a good teacher’s scope could be extended beyond the few students who would ordinarily benefit from such a demonstration. It would clearly have been more impressive in colour; but the key question was whether the more forceful teaching impact would justify the expense and technical hazards of a colour installation. Professor Warwick was more cheerful about the outlook for colour (for one thing, " black and white must always be second best ") than the American visitors, who had evidently had some dispiriting experiences. Dr. Murray C. Brown spoke of the financially disastrous efforts to reach a fully satisfactory colour system in the United States and of the troubles medical teachers had had in getting simple black-and-white systems to meet their needs at a price they could afford. And Dr. David S. Ruhe, of the University of Kansas School of Medicine, unhesitatingly favoured the use of the elementary and cheaper black-and-white until the emergence of exotic colour in more practical terms. Dr. E. W. Bird, of the Naval Medical Center across the way from Dr. Brown’s headquarters at the National Institutes of Health in Bethesda, painted a humorous picture of the distractions of colour, with viewers arguing that reproduction was too red or too blue and rather forgetting what it was all about. Five years ago, he said, almost everyone forecast that today colour would be the thing, but they had been very wrong. But like his colleagues he was much impressed by a film, shown to the conference by Dr. Brian Stanford, illustrating several forms of endoscopy televised in colour by a small two-colour camera developed by Minot in Marseilles. The colour range of this camera might not be adequate for other work, but here it seemed a big advance on those " giant creatures " (as Dr. Ruhe called them) at present necessary for full-scale colour reproduction. The conference also saw something of the exciting prospects made visible by fibre optics and the flexible fiberscope (the subject of Dr. Hirschowitz’s article on p. 1074) which will be an added stimulus to achieve cheaper and simpler colour television. So the present phase of despondency about colour and its expense may not last long. The cost of installing a one-camera colour system in an operating-theatre may be as great as that of equipping ten or more theatres with monochrome cameras 2 ; but the medical school with a little money to spend on television
teaching experiments might be able to invest a few hundred pounds in black-and-white equipment. No elaborate studio was needed (Dr. Ruhe was stern about those who declared that television teaching must have a special studio); and there were many advocates of " on the spot" television in operating-theatre, laboratory, or 1. See Lancet, 1957, ii, 1126. 2. Bird, E. W., Connolly, D. A. Medical-Dental TV Reference. American Medical Association (Communications Division), 1961.
lecture-theatre, with audience and demonstrator in direct touch, in contrast to most people’s idea of television teaching by a remote figure at some distance from his screenbound students. Using another technique, relatively simple equipment was sufficient for the demonstration, by Dr. David Stafford-Clark and Dr. B. L. Mallett, of how to preserve the privacy of a psychiatric interview and yet enable a large audience to look and listen in. Merely an expensive substitute for the one-way-vision "
screen " was one comment; but other responses were favourable. For this kind of teaching, black-andwhite seemed fully adequate. Again in dental teaching, with its emphasis on practical methods, television can display small operative details to large audience and this subject seems as certain as any to expand its use of television. more
" Medicine and dentistry still have a major task of sorting through the many remarkable items and gadgets of the commercial, educational and industrial television worlds to see which items of paraphernalia and which techniques of visualisation might serve their needs."2 They have indeed: and the teachers must establish as they go along that the introduction of a new television technique can always be justified by offering a definite advance over films, slides, and other aids to teaching. As the ASME conference was at pains to emphasise, the fascinations of electronics must not become too beguiling. ELECTRICAL ANÆSTHESIA AGAIN
IN theory the induction of anxsthesia by electricity has much to commend it; for it does not involve the use of potentially harmful drugs, and depends neither on continued lung ventilation nor on an intact circulation for the distribution and elimination of the anaesthetic agent. In practice, however, experience with electrical anaesthesia has not been encouraging. D’Arsonval used electric currents to produce unconsciousness in animals as long ago as 1890.a Over the years the most satisfactory technique proved to be the passage of an alternating current of some 25-75 milliamperes with a frequency of some 700-1500 cycles per second 4 to maintain the same depth of narcosis the strength of the current had to be increased as time went on. There were many difficulties. A current of this intensity caused pain at the point of its first application. Moreover it often produced generalised muscular contractions, amounting in some instances to a frank convulsion. In laboratory animals these movements interfered both with the patency of the upper airway and with the contractions of the respiratory muscles, and quite commonly anoxia ensued; parasympathetic overactivity manifested itself as bradycardia and salivation; cardiac irregularities were usual. al.° applied this method to man. They of the difficulties by premedication with and they administered gallamine triethiodide to atropine, control excessive muscle movement. They found, as had Hertz,6 that there were no reliable signs of anaesthesia: indeed the current might render the patient immobile and yet not insensible. Tachycardia, hypertension, and cardiac irregularity were sufficiently prominent and severe for Knutson et al. to be unwilling to continue the work. Those who used electronarcosis for the treatment of Knutson
et
overcame some
3. Cited by J. T. Gwathmey. Anœsthesia, 1914, p. 628. 4. Knutson, R. C. Anesthesiology, 1954, 15, 551. 5. Knutson, R. C., Tichy, F.Y., Reitman, J.H.ibid. 1956,
6.
Hertz, J.
Rev.
path. comp. 1933, 33, 385.
17, 815.
in amounts much greater than are and replacement of lamellar by woven bone ",10 rickets. As in hypo- Patients of this strictly defined group consitute a small nutritional required vitamin-D-resistant rickets, the need minority of all cases of azotaemic osteodystrophy: the phosphatoemic for large doses of vitamin D involves the hazard of over- bony changes are indistinguishable from those of dosage and hypercalcaemic intoxication. The individual primary hyperparathyroidism,16 the parathyroid glands patient may apparently have an unpredictable minimal are usually greatly hyperplastic, the plasma-phosphate dosage requirement, and huge doses (up to 200,000 i.u. is high and the plasma-calcium near normal, and meta[5 mg.] of calciferol daily) may sometimes be given static calcification is especially liable to develop sponwithout producing either clinical benefit or detectable taneously.17 Possibly the parathyroid glands in this metabolic effect.9’3 This particular problem can be syndrome become autonomously hyperfunctional (as solved only by metabolic balance measurements; and, apparently occurred in a case of chronic steatorrhoea although general therapeutic rules can be formulated,8 previously reported by DENT18) in which event large there is much to be said for treating these cases in centres doses of vitamin D may not cure the renal osteitis with resources for making such measurements. fibrosa. But whether the parathyroid glands are autoThe metabolic data from these ursemic patients are nomous or not, treatment with vitamin D would tend of interest in that the external mineral balances mimic to raise further, and dangerously, the already high the state in simple vitamin-D deficiency. In the plasma levels of calcium and phosphate. Consequently, untreated patient the faeces contain approximately the in the exceptional patient with bone changes of this same amount of calcium as is taken in the diet, and type, in whom the renal failure appears not to be rapidly the urinary calcium is negligible; the metabolic response advancing, parathyroidectomy may be indicated before to treatment with vitamin D resembles closely the starting treatment with vitamin D.13 response when nutritional rickets is treated with much Investigation of this fascinating group of disorders smaller doses of the vitamin. In the light of the lead should throw new light on the physiology of vitamin given by Lru and CHU,’ these observations have been D and of the parathyroid glands, especially when taken to suggest that in renal failure some factor inter- simpler techniques for vitamin and hormonal assay feres with the biological activity of vitamin D.89 come to hand. At present, cases investigated in Nothing is yet known of the mechanism of this apparent different centres can be compared only if the histoantagonism; but the curative effect of vitamin D in logical state of the bone is known precisely. Thus it is renal osteodystrophy does not seem to be mediated to be hoped that a carefully defined procedure for bone through change in the CaxP ionic product in the biopsy will be followed by all studying this problem.
each
must
be
to
given
cure
plasma.99
Osteitis fibrosa is present in all
of azotasmic Annotations osteodystrophy, even when the chief abnormality is rickets or osteomalacia, and it is nowadays thought to be caused by secondary hyperparathyroidism."-13 Both TELEVISION IN THE MEDICAL SCHOOL DENT 8 and STANBURY 9 13 have detected radiographic LAST week the Postmaster-General made public his evidence of healing of the characteristic cortical reasons for not acceding to the B.B.C.’s request for erosions 14 of secondary hyperparathyroidism during to operate a limited service of colour television; effective treatment with vitamin D. BALL,15 comparing permission and about the same time the Association for the Study of the histological appearances of bone from uraemic Medical Education (ASME), at its conference at the patients who had died after protracted treatment and London Hospital Medical College, was also hearing, of bone obtained by biopsy before treatment was though with rather different explanations, why some started, has shown that osteitis fibrosa is apparently people feel that colour television in medical teaching and reversible by vitamin-D therapy. Whereas the London research has not yet reached the stage for confident workers8 advocate treatment of renal hyperpara- advance and spending of money. Indeed the conference programme imaginatively arranged by the medical thyroidism with vitamin D, those in Manchester have (its committee of the Scientific Film Association) had almost criticised this as dangerous,12 and have resorted to as much to tell about impediments to the effective use of parathyroidectomy (which is obviously also potentially television in the medical school as about its positive powers. dangerous) before giving vitamin D to these patients.13 But the meeting provided an informative examination of a The difference is largely one of semantics, since the relatively new and complex instrument of teaching and former group rely on radiographic appearances for the research; and AsME is ably fulfilling its purpose in diagnosis of renal hyperparathyroidism, whereas the stimulating thought and debate on this sort of enterprise latter restrict the term azotxmic hyperparathyroidism -where enthusiasm may run as far as funds permit before it has looked very carefully where it is going. Enthusiasm, to cases in which the bone shows no histological evidence of defective mineralisation, the skeletal changes being however, seldom fails to meet scepticism; and, as Dr. John dominated by osteitis fibrosa and extensive remodelling Ellis, the Association’s secretary, related, the proposal to cases
"
Ball, J. in Recent Advances in Pathology (edited by C. V. Harrison). London, 1960. 11. Gilmour, J. R. The Parathyroid Glands and Skeleton in Renal Disease. London, 1947. 12. Stanbury, S. W. Brit. med. Bull. 1957, 13, 57. 13. Stanbury, S. W., Lumb, G. A., Nicholson, W. F. Lancet, 1960, i, 793. 14. Pugh, D. B. Amer. J. Roentgenol. 1951, 66, 577. 15. Ball, J. Personal communication.
10.
hold a conference on television in the medical school had its opponents ("No, I still prefer the personal approach"); 16. 17.
Albright, F., Reifenstein, E. C., Jr. The Parathyroid Glands and Metabolic Bone Disease. London, 1948. Herbert, F. K., Miller, H. G., Richardson, G. O. J. Path. Bact. 1941,
53, 161. 18. Davies, D.
R., Dent, C. E., Willcox, A. Brit. med. J. 1956, ii,
1133.
1103 but if the doubters were many their voices were few last week, and the main message of the meeting was that, despite technical misgivings and questions about details of application, television has a place in the medical school as an extension of the power and range of the teacher-
though never as a dominating technique. Thus, the quality of the teacher mattered more than the mechanism of his teaching, declared Prof. Roger Warwick, the Guy’s anatomist, who has been among the most active examiners of television as a teaching medium in British medical schools (he took a large share in organising the colour demonstration of medical teaching from Alexandra Palace in 1957 ’). Last week a black-andwhite screening of a dissected hand illustrated how a good teacher’s scope could be extended beyond the few students who would ordinarily benefit from such a demonstration. It would clearly have been more impressive in colour; but the key question was whether the more forceful teaching impact would justify the expense and technical hazards of a colour installation. Professor Warwick was more cheerful about the outlook for colour (for one thing, " black and white must always be second best ") than the American visitors, who had evidently had some dispiriting experiences. Dr. Murray C. Brown spoke of the financially disastrous efforts to reach a fully satisfactory colour system in the United States and of the troubles medical teachers had had in getting simple black-and-white systems to meet their needs at a price they could afford. And Dr. David S. Ruhe, of the University of Kansas School of Medicine, unhesitatingly favoured the use of the elementary and cheaper black-and-white until the emergence of exotic colour in more practical terms. Dr. E. W. Bird, of the Naval Medical Center across the way from Dr. Brown’s headquarters at the National Institutes of Health in Bethesda, painted a humorous picture of the distractions of colour, with viewers arguing that reproduction was too red or too blue and rather forgetting what it was all about. Five years ago, he said, almost everyone forecast that today colour would be the thing, but they had been very wrong. But like his colleagues he was much impressed by a film, shown to the conference by Dr. Brian Stanford, illustrating several forms of endoscopy televised in colour by a small two-colour camera developed by Minot in Marseilles. The colour range of this camera might not be adequate for other work, but here it seemed a big advance on those " giant creatures " (as Dr. Ruhe called them) at present necessary for full-scale colour reproduction. The conference also saw something of the exciting prospects made visible by fibre optics and the flexible fiberscope (the subject of Dr. Hirschowitz’s article on p. 1074) which will be an added stimulus to achieve cheaper and simpler colour television. So the present phase of despondency about colour and its expense may not last long. The cost of installing a one-camera colour system in an operating-theatre may be as great as that of equipping ten or more theatres with monochrome cameras 2 ; but the medical school with a little money to spend on television
teaching experiments might be able to invest a few hundred pounds in black-and-white equipment. No elaborate studio was needed (Dr. Ruhe was stern about those who declared that television teaching must have a special studio); and there were many advocates of " on the spot" television in operating-theatre, laboratory, or 1. See Lancet, 1957, ii, 1126. 2. Bird, E. W., Connolly, D. A. Medical-Dental TV Reference. American Medical Association (Communications Division), 1961.
lecture-theatre, with audience and demonstrator in direct touch, in contrast to most people’s idea of television teaching by a remote figure at some distance from his screenbound students. Using another technique, relatively simple equipment was sufficient for the demonstration, by Dr. David Stafford-Clark and Dr. B. L. Mallett, of how to preserve the privacy of a psychiatric interview and yet enable a large audience to look and listen in. Merely an expensive substitute for the one-way-vision "
screen " was one comment; but other responses were favourable. For this kind of teaching, black-andwhite seemed fully adequate. Again in dental teaching, with its emphasis on practical methods, television can display small operative details to large audience and this subject seems as certain as any to expand its use of television. more
" Medicine and dentistry still have a major task of sorting through the many remarkable items and gadgets of the commercial, educational and industrial television worlds to see which items of paraphernalia and which techniques of visualisation might serve their needs."2 They have indeed: and the teachers must establish as they go along that the introduction of a new television technique can always be justified by offering a definite advance over films, slides, and other aids to teaching. As the ASME conference was at pains to emphasise, the fascinations of electronics must not become too beguiling. ELECTRICAL ANÆSTHESIA AGAIN
IN theory the induction of anxsthesia by electricity has much to commend it; for it does not involve the use of potentially harmful drugs, and depends neither on continued lung ventilation nor on an intact circulation for the distribution and elimination of the anaesthetic agent. In practice, however, experience with electrical anaesthesia has not been encouraging. D’Arsonval used electric currents to produce unconsciousness in animals as long ago as 1890.a Over the years the most satisfactory technique proved to be the passage of an alternating current of some 25-75 milliamperes with a frequency of some 700-1500 cycles per second 4 to maintain the same depth of narcosis the strength of the current had to be increased as time went on. There were many difficulties. A current of this intensity caused pain at the point of its first application. Moreover it often produced generalised muscular contractions, amounting in some instances to a frank convulsion. In laboratory animals these movements interfered both with the patency of the upper airway and with the contractions of the respiratory muscles, and quite commonly anoxia ensued; parasympathetic overactivity manifested itself as bradycardia and salivation; cardiac irregularities were usual. al.° applied this method to man. They of the difficulties by premedication with and they administered gallamine triethiodide to atropine, control excessive muscle movement. They found, as had Hertz,6 that there were no reliable signs of anaesthesia: indeed the current might render the patient immobile and yet not insensible. Tachycardia, hypertension, and cardiac irregularity were sufficiently prominent and severe for Knutson et al. to be unwilling to continue the work. Those who used electronarcosis for the treatment of Knutson
et
overcame some
3. Cited by J. T. Gwathmey. Anœsthesia, 1914, p. 628. 4. Knutson, R. C. Anesthesiology, 1954, 15, 551. 5. Knutson, R. C., Tichy, F.Y., Reitman, J.H.ibid. 1956,
6.
Hertz, J.
Rev.
path. comp. 1933, 33, 385.
17, 815.