761
adequate.17 British psychiatrists may of* ject-based. That is, the student is exposed to teaching in a series of different disciplines which by the end of the be better informed. course, it is hoped, will have given the young doctor the This white-paper illustrates the strengths and basic information and skills he or she needs before weaknesses of the classic British compromise. The embarking upon a medical career. In many medical central question of the definition of mental illness schools attempts have been made at breaking down the is completely dodged, despite the evident dangers of barriers between subjects by "integrated" teachingleaving this issue open to different cultural and where, for example, the cardiovascular system is studied social interpretations and the tendency of psychiin all its aspects=but these methods have not led to any atrists to diagnose psychiatric disease where it is fundamental change of attitude among teachers. A absent.18,19 The idea that mental illness is a medical group from the University of Illinois,’ on behalf of the in entrenched British and is World Health Organisation, have now prepared an inlegal responsibility troduction to "competency-based" teaching. Essentially, medical thought, and so it should be. But this on the a they are discussing how to construct a medical training professionals places special responsibility starting with the question: "What do we need to teach criteria commitment and to for to tighten the in order to produce competent doctors?" The question is widen the scope for peer review, multidisciplinary a simple one to ask but the amount of published work supervision, and public accountability. It is not on the subject shows that it is by no means simple to enough for psychiatrists to point to their high stananswer. To define what knowledge and skills are dards and codes of practice, for they are rarely in required to carry out, say, a tracheostomy, is one thing; but trying to split up the whole of a doctor’s work into question. What disturbs observers is the danger that psychiatrists, nurses, and social workers may a series of competencies is simply another form of fragbecome the agents of thought control and political mentation, and anyway much that a doctor needs to know cannot be set out in such a precise manner, as the indoctrination through an insidious, even unwitIllinois group are well aware. Many of the principles of ting process. The present opportunity to allay such competency-based medical education would meet little misgivings by constructing a piece of mental-health from any quarter: defining what the students legislation which permits the widest possible indi- objection need to learn, deciding how this objective should be vidual freedom while protecting the seriously achieved, and then measuring the efficacy of the instrucpsychotic from harming themselves or others, if tion. The difficulty comes in determining the content of seized courageously, could represent a new point of the courses, and on the relative importance of the different topics. What is more, the needs of a country departure. As it stands, the white-paper, for all its where there is 1 doctor per 29 000 population (and 1 good intentions, has all the appearance of tinkernurse for 43 000) with about$1 per head to spend on with the is a when what is ing engine required health services will be quite different from those where overhaul of all the thorough parts. to
be
course
HOW TO TRAIN DOCTORS
STUDENTS ask:
"Why do we have to learn so much anaAnstomy-physiology-biochemistry-cell biology-&c?" wer : "Because they are there." "They" in these cases is not so much the subject matter as the large university departments which do the teaching. If courses are modified drastically, as most contributors to the medical education debate suggest that they should be, then certain .departments will be threatened because a change of emphasis in undergraduate teaching means a change of importance for these departments, and no one wants to relinquish resources. Although the responsibilities of medical schools include the training of doctors, only an optimist would suppose that medical teachers ever sit down together and ask themselves: "what must we teach these young men and women to make them into good doctors?" Thus it is still possible in Britain for the anatomy of the nervous system to be taught separately from the physiology of the nervous system, and for a medical school to devote one month to perinatology and no time at all to geriatrics. Prolonged and acrimonious negotiation has sometimes been needed to secure a place for behavioural-science teaching in the preclinical curriculum. Medical education in 17 Peszke. M
most
parts of the world is sub-
there is 1 doctor per 960 persons (and 1 nurse per 200) and$100 per head to spend. Throughout their report the Illinois team point to the conservatism that hinders progress. Distinction in research brings the greatest prestige and opportunities for travel abroad and larger research grants, while "creative work in medical education is the function least likely to bring academic recognition or reward." In highly developed Western societies medical research and improved health services are unlikely to have any noticeable impact on the quality of life of the general population. The same is certainly not true for the rest of the world, yet many of the medical teachers in the developing countries have themselves been taught in high-technology Western medical centres; and many developing countries have fallen for the expensive Western pattern teaching hospital in the capital which absorbs a large part of the nation’s health budget and tends to perpetuate hospital-based specialist teaching. The Illinois group are suggesting changes which, for once, do not primarily involve cash, and they recognise that "the greatest impediments are found in the heart, not in the purse." As they see it, the only hope of improving medical education and making it more relevant to the different things doctors do in different parts of the world is for the status of medical teachers to be enhanced in relation to that of researchers; for the pressure for change from outside the medical profession to
A., Wintrob,R.M. Am. J.Psychiat.1974, 131, 36.
Rosenhan, D.L. Science, 1973, 179, 250. 19 Kittrie, N.N.The Right to be Different: Deviance and Enforced
18
Baltimore, 1972.
W. C., Miller, G. E , Sajid, A. W, Telder, T. V. CompetencyBased Curriculum Development in Medical Education An Introduction PublicHealthPapers no. 68 .World Health Organisation, Geneva, 1978.
1. McGaghie,
Therapy.
762
stiffen
substantially; and for medical-school staff to apply to teaching methods the same rigorous scrutiny which they so effectively apply to their academic inquiries.
magnesium salts12 might have a beneficial effecton ischaemic heart-disease, perhaps, as well as on retinopathy.
-
BIOCHEMISTRY OF SURFACTANT HYPOMAGNESÆMIA AND DIABETIC RETINOPATHY THERE is much interest in the possible contribution of suboptimal concentrations of magnesium in ischæmic heart-disease.’-3 Diabetic patients are at increased risk of ischæmic heart disease, and a new study has revealed a significant relation between low concentrations of magnesium in the serum and another vascular complication of diabetes, diabetic retinopathy.’ McNair and his coworkers4 have investigated possible risk factors in patients who had had diabetes for ten to twenty years and 194 normal controls. The diabetic patients were divided by a single observer into two groups: group A (45) had normal fundi or minor changes; group B (26) had more severe changes such as microaneurysms with large haemorrhages and/or exudates and proliferative retinopathy. In the diabetic patients serum-magnesium was significantly lower (0 - 74 + 0 - 012 mmol/1) than in the normal controls (083+_0007). In addition, group B with severe retinopathy had significantly lower serum-magnesiums (0-72±0.018 mmol/1) than group A (0.75 ± 0.014). Groups A and B did not differ significantly from controls with respect to serum concentrations of potassium,
calcium, glucose, lipids, parathyroid hormone, and C-peptide. Group B contained a higher proportion of smokers than group A-reinforcing earlier observations on an association between smoking and retinopathy5,6 - but there was no evidence that serum concentrations of magnesium were related to smoking habits. This work suggests that low concentrations of magnesium may be an additional risk factor in the development of diabetic retinopathy. The reason for the low serum-magnesium in the diabetic patients is obscure. As McNair and others point out, if there was increased urinary excretion of magnesium the metabolism of calcium would also be expected to alter,7-9 and there was no evidence for this in their patients. Serum-magnesium concentrations are not necessarily a good indication of intracellular magnesium, so that the magnesium content of the cells in diabetic patients may well be decreased even more than the serum magnesium. We are by no means sure that strict control of bloodglucose will prevent diabetic retinopathy,1O so other methods of prevention should be explored. Magnesium salts are not very toxic" and cautious administration of Seelig, M. S Adv. cardiac Struct. Metab. 1972, 1, 626. Seelig, M. S., Heggtveit, H. A Am J clin Nutr 1974, 27, 59 3. Chipperfield, B., Chipperfield, J. R. Am. Heart J. 1977, 93, 679. 4. MeNair, I’ , Christiansen, C., Madsbad, S , Lauritzen, E., Faber, O., Binder, C., Transbøl, I. Diabetes, 1978, 27, 1075 5. Paetkau, M. E., Boyd, T. A. S., Winship, B., Grace, M. Diabetes, 1977, 26, 1. 2
46 6. Lancet, 1977, i, 841. 7. I indemann, R. D., Adler, S.,
Yiengst, M. J., Beard, E S. J Lab. clin. Med. 1967, 70, 236. 8 Lemann, J, Lennon, E. J., Piering, W. R , Prien, E. L, Ricanati, E. S. ibid. 1970, 75, 578 9 Lennon, E J, Lemann, J., Piering, W. F., Larson, L. S. J clin. Invest. 1974, 53, 1424 10. Siperstein, M. D., Foster, D. W., Knowles, H. C., Levine, R., Madison, L. L., Roth, J New Engl J. Med. 1977, 296, 1060. 11 Venugopal, B, Luckey, T. D. Metal Toxicity in Mammals, vol. II, New York, 1978.
THE underlying process in hyaline-membrane disease of preterm infants is a deficiency of surfactant.’ This substance, produced by cells of the alveolar lining, enables the full-term infant to emerge safely from its aquatic intrauterine environment, and exist independently in air. It acts at the air/liquid interface throughout the lungs and opposes the effects of surface tension which would otherwise cause alveoli to collapse. Whether or not a preterm infant is able to survive after birth depends largely on the biochemical maturity of the lungs. If surfactant is present in sufficient quantity the lungs remain structurally stable. If not, progressive alveolar collapse occurs, giving rise to the familiar clinical picture of hyaline-membrane disease with cyanosis, grunting, and respiratory distress. Surfactant has proved remarkably amenable to study, even in the maturing fetus in utero: the lining cells of the alveoli actively secrete fluid which passes up the trachea to the pharynx, and some of this finds it way into the amniotic cavity where it is available for sampling by amniocentesis.2 Many units, in making the decision whether or not to deliver an infant thought to be at risk in utero, assess fetal-lung maturity by measuring surfactant in an attempt to predict the onset or severity of hyaline-membrane disease.3 In this case the progress of the disease can be so rapid that the infant provides the answer before a biochemical test result is to hand, but rapid tests which depend on the physical properties of surfactant4 can be carried out and have a useful predictive value. Pulmonary surfactant is biochemically complex, but a major constituent is phospholipid, usually measured as lecithin. Shelley et al. now report that not only the amount but also the precise composition of surface active phospholipid may be important in determining whether or not an infant will get hyaline-membrane disease.
Using a density-gradient centrifuge technique they
have been able to obtain adequate phospholipid for analysis even from heavily contaminated aspirates from infants with clinical surfactant dificiency. They studied 20 preterm infants with hyaline-membrane disease and 12 infants without the disease but of similar gestational age; the fatty-acid composition of phospholipid from the affected group of infants was significantly different from that of the control group, and in those who survived the composition gradually changed over several days to resemble mature surfactant. This study is a valuable contribution to our understanding of the pathophysiology of hyaline membrane disease. But what is its message for the neonatal pxdiatrician ? These tests require elaborate laboratory techniques and presumably could not be done 24 hours a day. It is unlikely then that they would affect the management of the newly born immature infant. But Whacker, W. E. C., Parisi, A. F. New Engl J. Med. 1968, 278, 772. Strang, L. B. Neonatal Respiration; p. 181. Oxford, 1977. Gluck, L., Kulovitch, M. V, Borer, R. C. J., et al. Am. J. of Obstet Gynec 1971, 109, 440. 3 Weller, P. H , Jenkins, P. A., Gupta, J., et al. Lancet, 1976, i, 12. 4. Evans, J. J. New Engl. JMed. 1975, 292, 1113 5. Shelley, S. A., Kovalevic, M., Paciga, J. F., Balis, J. N. ibid 1979, 300, 112
12 1. 2
adequate.17 British psychiatrists may of* ject-based. That is, the student is exposed to teaching in a series of different disciplines which by the end of the be better informed. course, it is hoped, will have given the young doctor the This white-paper illustrates the strengths and basic information and skills he or she needs before weaknesses of the classic British compromise. The embarking upon a medical career. In many medical central question of the definition of mental illness schools attempts have been made at breaking down the is completely dodged, despite the evident dangers of barriers between subjects by "integrated" teachingleaving this issue open to different cultural and where, for example, the cardiovascular system is studied social interpretations and the tendency of psychiin all its aspects=but these methods have not led to any atrists to diagnose psychiatric disease where it is fundamental change of attitude among teachers. A absent.18,19 The idea that mental illness is a medical group from the University of Illinois,’ on behalf of the in entrenched British and is World Health Organisation, have now prepared an inlegal responsibility troduction to "competency-based" teaching. Essentially, medical thought, and so it should be. But this on the a they are discussing how to construct a medical training professionals places special responsibility starting with the question: "What do we need to teach criteria commitment and to for to tighten the in order to produce competent doctors?" The question is widen the scope for peer review, multidisciplinary a simple one to ask but the amount of published work supervision, and public accountability. It is not on the subject shows that it is by no means simple to enough for psychiatrists to point to their high stananswer. To define what knowledge and skills are dards and codes of practice, for they are rarely in required to carry out, say, a tracheostomy, is one thing; but trying to split up the whole of a doctor’s work into question. What disturbs observers is the danger that psychiatrists, nurses, and social workers may a series of competencies is simply another form of fragbecome the agents of thought control and political mentation, and anyway much that a doctor needs to know cannot be set out in such a precise manner, as the indoctrination through an insidious, even unwitIllinois group are well aware. Many of the principles of ting process. The present opportunity to allay such competency-based medical education would meet little misgivings by constructing a piece of mental-health from any quarter: defining what the students legislation which permits the widest possible indi- objection need to learn, deciding how this objective should be vidual freedom while protecting the seriously achieved, and then measuring the efficacy of the instrucpsychotic from harming themselves or others, if tion. The difficulty comes in determining the content of seized courageously, could represent a new point of the courses, and on the relative importance of the different topics. What is more, the needs of a country departure. As it stands, the white-paper, for all its where there is 1 doctor per 29 000 population (and 1 good intentions, has all the appearance of tinkernurse for 43 000) with about$1 per head to spend on with the is a when what is ing engine required health services will be quite different from those where overhaul of all the thorough parts. to
be
course
HOW TO TRAIN DOCTORS
STUDENTS ask:
"Why do we have to learn so much anaAnstomy-physiology-biochemistry-cell biology-&c?" wer : "Because they are there." "They" in these cases is not so much the subject matter as the large university departments which do the teaching. If courses are modified drastically, as most contributors to the medical education debate suggest that they should be, then certain .departments will be threatened because a change of emphasis in undergraduate teaching means a change of importance for these departments, and no one wants to relinquish resources. Although the responsibilities of medical schools include the training of doctors, only an optimist would suppose that medical teachers ever sit down together and ask themselves: "what must we teach these young men and women to make them into good doctors?" Thus it is still possible in Britain for the anatomy of the nervous system to be taught separately from the physiology of the nervous system, and for a medical school to devote one month to perinatology and no time at all to geriatrics. Prolonged and acrimonious negotiation has sometimes been needed to secure a place for behavioural-science teaching in the preclinical curriculum. Medical education in 17 Peszke. M
most
parts of the world is sub-
there is 1 doctor per 960 persons (and 1 nurse per 200) and$100 per head to spend. Throughout their report the Illinois team point to the conservatism that hinders progress. Distinction in research brings the greatest prestige and opportunities for travel abroad and larger research grants, while "creative work in medical education is the function least likely to bring academic recognition or reward." In highly developed Western societies medical research and improved health services are unlikely to have any noticeable impact on the quality of life of the general population. The same is certainly not true for the rest of the world, yet many of the medical teachers in the developing countries have themselves been taught in high-technology Western medical centres; and many developing countries have fallen for the expensive Western pattern teaching hospital in the capital which absorbs a large part of the nation’s health budget and tends to perpetuate hospital-based specialist teaching. The Illinois group are suggesting changes which, for once, do not primarily involve cash, and they recognise that "the greatest impediments are found in the heart, not in the purse." As they see it, the only hope of improving medical education and making it more relevant to the different things doctors do in different parts of the world is for the status of medical teachers to be enhanced in relation to that of researchers; for the pressure for change from outside the medical profession to
A., Wintrob,R.M. Am. J.Psychiat.1974, 131, 36.
Rosenhan, D.L. Science, 1973, 179, 250. 19 Kittrie, N.N.The Right to be Different: Deviance and Enforced
18
Baltimore, 1972.
W. C., Miller, G. E , Sajid, A. W, Telder, T. V. CompetencyBased Curriculum Development in Medical Education An Introduction PublicHealthPapers no. 68 .World Health Organisation, Geneva, 1978.
1. McGaghie,
Therapy.
762
stiffen
substantially; and for medical-school staff to apply to teaching methods the same rigorous scrutiny which they so effectively apply to their academic inquiries.
magnesium salts12 might have a beneficial effecton ischaemic heart-disease, perhaps, as well as on retinopathy.
-
BIOCHEMISTRY OF SURFACTANT HYPOMAGNESÆMIA AND DIABETIC RETINOPATHY THERE is much interest in the possible contribution of suboptimal concentrations of magnesium in ischæmic heart-disease.’-3 Diabetic patients are at increased risk of ischæmic heart disease, and a new study has revealed a significant relation between low concentrations of magnesium in the serum and another vascular complication of diabetes, diabetic retinopathy.’ McNair and his coworkers4 have investigated possible risk factors in patients who had had diabetes for ten to twenty years and 194 normal controls. The diabetic patients were divided by a single observer into two groups: group A (45) had normal fundi or minor changes; group B (26) had more severe changes such as microaneurysms with large haemorrhages and/or exudates and proliferative retinopathy. In the diabetic patients serum-magnesium was significantly lower (0 - 74 + 0 - 012 mmol/1) than in the normal controls (083+_0007). In addition, group B with severe retinopathy had significantly lower serum-magnesiums (0-72±0.018 mmol/1) than group A (0.75 ± 0.014). Groups A and B did not differ significantly from controls with respect to serum concentrations of potassium,
calcium, glucose, lipids, parathyroid hormone, and C-peptide. Group B contained a higher proportion of smokers than group A-reinforcing earlier observations on an association between smoking and retinopathy5,6 - but there was no evidence that serum concentrations of magnesium were related to smoking habits. This work suggests that low concentrations of magnesium may be an additional risk factor in the development of diabetic retinopathy. The reason for the low serum-magnesium in the diabetic patients is obscure. As McNair and others point out, if there was increased urinary excretion of magnesium the metabolism of calcium would also be expected to alter,7-9 and there was no evidence for this in their patients. Serum-magnesium concentrations are not necessarily a good indication of intracellular magnesium, so that the magnesium content of the cells in diabetic patients may well be decreased even more than the serum magnesium. We are by no means sure that strict control of bloodglucose will prevent diabetic retinopathy,1O so other methods of prevention should be explored. Magnesium salts are not very toxic" and cautious administration of Seelig, M. S Adv. cardiac Struct. Metab. 1972, 1, 626. Seelig, M. S., Heggtveit, H. A Am J clin Nutr 1974, 27, 59 3. Chipperfield, B., Chipperfield, J. R. Am. Heart J. 1977, 93, 679. 4. MeNair, I’ , Christiansen, C., Madsbad, S , Lauritzen, E., Faber, O., Binder, C., Transbøl, I. Diabetes, 1978, 27, 1075 5. Paetkau, M. E., Boyd, T. A. S., Winship, B., Grace, M. Diabetes, 1977, 26, 1. 2
46 6. Lancet, 1977, i, 841. 7. I indemann, R. D., Adler, S.,
Yiengst, M. J., Beard, E S. J Lab. clin. Med. 1967, 70, 236. 8 Lemann, J, Lennon, E. J., Piering, W. R , Prien, E. L, Ricanati, E. S. ibid. 1970, 75, 578 9 Lennon, E J, Lemann, J., Piering, W. F., Larson, L. S. J clin. Invest. 1974, 53, 1424 10. Siperstein, M. D., Foster, D. W., Knowles, H. C., Levine, R., Madison, L. L., Roth, J New Engl J. Med. 1977, 296, 1060. 11 Venugopal, B, Luckey, T. D. Metal Toxicity in Mammals, vol. II, New York, 1978.
THE underlying process in hyaline-membrane disease of preterm infants is a deficiency of surfactant.’ This substance, produced by cells of the alveolar lining, enables the full-term infant to emerge safely from its aquatic intrauterine environment, and exist independently in air. It acts at the air/liquid interface throughout the lungs and opposes the effects of surface tension which would otherwise cause alveoli to collapse. Whether or not a preterm infant is able to survive after birth depends largely on the biochemical maturity of the lungs. If surfactant is present in sufficient quantity the lungs remain structurally stable. If not, progressive alveolar collapse occurs, giving rise to the familiar clinical picture of hyaline-membrane disease with cyanosis, grunting, and respiratory distress. Surfactant has proved remarkably amenable to study, even in the maturing fetus in utero: the lining cells of the alveoli actively secrete fluid which passes up the trachea to the pharynx, and some of this finds it way into the amniotic cavity where it is available for sampling by amniocentesis.2 Many units, in making the decision whether or not to deliver an infant thought to be at risk in utero, assess fetal-lung maturity by measuring surfactant in an attempt to predict the onset or severity of hyaline-membrane disease.3 In this case the progress of the disease can be so rapid that the infant provides the answer before a biochemical test result is to hand, but rapid tests which depend on the physical properties of surfactant4 can be carried out and have a useful predictive value. Pulmonary surfactant is biochemically complex, but a major constituent is phospholipid, usually measured as lecithin. Shelley et al. now report that not only the amount but also the precise composition of surface active phospholipid may be important in determining whether or not an infant will get hyaline-membrane disease.
Using a density-gradient centrifuge technique they
have been able to obtain adequate phospholipid for analysis even from heavily contaminated aspirates from infants with clinical surfactant dificiency. They studied 20 preterm infants with hyaline-membrane disease and 12 infants without the disease but of similar gestational age; the fatty-acid composition of phospholipid from the affected group of infants was significantly different from that of the control group, and in those who survived the composition gradually changed over several days to resemble mature surfactant. This study is a valuable contribution to our understanding of the pathophysiology of hyaline membrane disease. But what is its message for the neonatal pxdiatrician ? These tests require elaborate laboratory techniques and presumably could not be done 24 hours a day. It is unlikely then that they would affect the management of the newly born immature infant. But Whacker, W. E. C., Parisi, A. F. New Engl J. Med. 1968, 278, 772. Strang, L. B. Neonatal Respiration; p. 181. Oxford, 1977. Gluck, L., Kulovitch, M. V, Borer, R. C. J., et al. Am. J. of Obstet Gynec 1971, 109, 440. 3 Weller, P. H , Jenkins, P. A., Gupta, J., et al. Lancet, 1976, i, 12. 4. Evans, J. J. New Engl. JMed. 1975, 292, 1113 5. Shelley, S. A., Kovalevic, M., Paciga, J. F., Balis, J. N. ibid 1979, 300, 112
12 1. 2
