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DETERMINING PROTEINS IN LOW CONCENTRATION
1059
the patient was in good health and denied any respiraA pre-employment radiograph two tory symptoms. normal. When nothing else could had been earlier years be found to account for the conditions, the patient was asked about inhalants. She had used a hair-spray almost daily, sometimes twice a day, for about three years. Two months after stopping the use of the spray, radiography showed regression, and another month later the picture was virtually normal. These stories seem simple in retrospect, but consternation was caused by the discovery of an apparently serious, widespread infiltrative process in the lungs in supposedly healthy young women. Bergmann et al. could not determine the exact nature of the particulate matter found in the lymph-glands in the first case. They evaporated to dryness 20 ml. quantities of hairspray, suspended the residues in saline solution, and injected the suspension subcutaneously into guineapigs. One to two months later the sites of injection showed granulomatous lesions in which particulate matter was found in foam cells, and similar granules were found sometimes in liver, spleen, or lung. The reaction was typical of the macromolecular substance reactiongiven by the various natural and synthetic resins used in cosmetics as well as for many other purposes. While most of these substances are chemically inert, and relatively large quantities may be stored in the reticulo-endothelial system without affecting function, there is always the possibility that one may be carcinogenic 9; and the diagnostic difficudes to which they may give rise should be generally recognised. DETERMINING PROTEINS IN LOW
CONCENTRATION
methods for determining the relaof protein that may be present in tively such as urine and cerebrospinal fluid, biological fluids, involve either gravimetric estimation after precipitation, or estimation of the nitrogen content of the precipitated and washed protein by the micro-Kjeldahl technique. But these methods are time-consuming and thus unsuitable for use in busv routine laboratories. All the methods in routine use sacrifice, to some extent, accuracy for speed. They depend either on estimation of the volume of the precipitated protein, as in the unsatisfactory Esbach method, or, better, on precipitation of protein and comparison of the resulting turbidity with turbidimetric standards, or, better still, on comparison of the colour developed in the biuret reaction with that developed by a standard biuret or standard protein solution. This last method usually gives an answer within 5% of that given by a micro-Kjeldahl technique.1O The error of the turbidimetric methods is usually less than 10%, but occasionally may be as high as 20%.11 The Esbach method may give results varying from half to twice the true amount.12 Closs 13 has described a new reagent for precipitating urinary proteins, which are then determined turbidimetrically in a photoelectric colorimeter. The reagent is an 0-2% solution of sodium polythionate brought to a pH of about 2. 1 ml. of urine is mixed with 10 ml. of reagent in the cold, and the turbidity produced after 30 minutes can be assessed qualitatively or estimated THE
most accurate
small
amounts
8. Hueper, W. C. Arch. Path. 1942, 33, 267. 9. Hueper, W. C. Cancer, 1957, 10, 8. 10. Hiller, A., Greif, R. L., Beckman, W. W.,
Plazin, J. J. biol. Chem.
1948, 176, 1421. 11. Varley, H. Practical Clinical Chemistry. London, 1954. 12. Peters, J. P., Van Slyke, D. D. Quantitative Clinical Chemistry; vol. 2.
London, 1932. Scand. J. clin. Lab. Invest. 1957 9, 349.
13. Closs, K.
quantitatively. The reagent is made freshly each week from a stock solution, which will keep indefinitely at room-temperature. Closs finds that, qualitatively, the method is as sensitive as Heller’s test, which will detect 7 mg. of protein per 100 ml.’4 Quantitatively the method, applied to urinary protein, appeared to agree somewhat more closely with the micro-Kjeldahl technique than is usual with turbidimetric procedures. Its usefulness in other the content of determining protein biological fluids has yet to be ascertained. This method has certain small advantages, in that the amount of fluid required is 1 ml. or less, the degree of dilution reduces the error that may arise with initially turbid urines, no heating is necessary, and interfering precipitations or colorations are rare. SURVEY OF CHILDREN
IT is a matter of common clinical experience that infants and children from poor homes do not thrive as well as the socially better favoured. But the precise effects of social conditions on physical and mental health and development are not easily defined. A study by Douglas and Blomfield 15 provides much long-awaited material. The starting-point of the work was the investigation by the Population Investigation Committee and the Royal College of Obstetricians and Gynaecologists into the circumstances and costs of all confinements in Great Britain during the first week of March, 1946. Of the 14,000 families involved in that inquiry 16 5000 children were selected for longitudinal study, and it is their lifestories up to the age of 5 that Douglas and Blomfield are now concerned with. These children spent their early years in the unsettled post-war era and have been subject to the manifold social changes of the time, not least of which was the inception of the National Health Service when they were 2. During the survey period (1946-50) housing conditions steadily improved, and many of the families moved upward in the social scale. This background has to be remembered in assessing some of the findings of the survey,. or in extrapolating conclusions for present-day needs. Poor social conditions showed differing effects according to the age of the child. In the perinatal period such conditions were associated with an increase in prematurity and neonatal death, in infancy with early and and in childhood with severe respiratory infections, of significant depression growth. At all ages the direct cause of socially determined disorders was " maternal inefficiency " with poverty, overcrowding, and large families appearing as predisposing factors. The report shows clearly that successful mothering of a large family, where the housing conditions are poor and the budget is slender, requires care, resourcefulness, education, and supportive advice. The best showing was made by the families of " black-coated workers ". As a group they are not materially better favoured than skilled workers; but by care, ability, and utilisation of child-welfare services they achieve not only favourable development for their children but also often fulfilment of their social
aspirations. Douglas and Blomfield feel that " the social and educational approach " offered by the local-authority 14. Harrison, G. A. Chemical Methods in Clinical Medicine. London, 1957. 15. Children Under Five. By J. W. B. DOUGLAS and J. M. BLOMFIELD. London: Allen & Unwin. 1958. Pp. 177. 21s. 16. Maternity in Great Britain. London, 1948. See Lancet, 1948, ii, 813.
the patient was in good health and denied any respiraA pre-employment radiograph two tory symptoms. normal. When nothing else could had been earlier years be found to account for the conditions, the patient was asked about inhalants. She had used a hair-spray almost daily, sometimes twice a day, for about three years. Two months after stopping the use of the spray, radiography showed regression, and another month later the picture was virtually normal. These stories seem simple in retrospect, but consternation was caused by the discovery of an apparently serious, widespread infiltrative process in the lungs in supposedly healthy young women. Bergmann et al. could not determine the exact nature of the particulate matter found in the lymph-glands in the first case. They evaporated to dryness 20 ml. quantities of hairspray, suspended the residues in saline solution, and injected the suspension subcutaneously into guineapigs. One to two months later the sites of injection showed granulomatous lesions in which particulate matter was found in foam cells, and similar granules were found sometimes in liver, spleen, or lung. The reaction was typical of the macromolecular substance reactiongiven by the various natural and synthetic resins used in cosmetics as well as for many other purposes. While most of these substances are chemically inert, and relatively large quantities may be stored in the reticulo-endothelial system without affecting function, there is always the possibility that one may be carcinogenic 9; and the diagnostic difficudes to which they may give rise should be generally recognised. DETERMINING PROTEINS IN LOW
CONCENTRATION
methods for determining the relaof protein that may be present in tively such as urine and cerebrospinal fluid, biological fluids, involve either gravimetric estimation after precipitation, or estimation of the nitrogen content of the precipitated and washed protein by the micro-Kjeldahl technique. But these methods are time-consuming and thus unsuitable for use in busv routine laboratories. All the methods in routine use sacrifice, to some extent, accuracy for speed. They depend either on estimation of the volume of the precipitated protein, as in the unsatisfactory Esbach method, or, better, on precipitation of protein and comparison of the resulting turbidity with turbidimetric standards, or, better still, on comparison of the colour developed in the biuret reaction with that developed by a standard biuret or standard protein solution. This last method usually gives an answer within 5% of that given by a micro-Kjeldahl technique.1O The error of the turbidimetric methods is usually less than 10%, but occasionally may be as high as 20%.11 The Esbach method may give results varying from half to twice the true amount.12 Closs 13 has described a new reagent for precipitating urinary proteins, which are then determined turbidimetrically in a photoelectric colorimeter. The reagent is an 0-2% solution of sodium polythionate brought to a pH of about 2. 1 ml. of urine is mixed with 10 ml. of reagent in the cold, and the turbidity produced after 30 minutes can be assessed qualitatively or estimated THE
most accurate
small
amounts
8. Hueper, W. C. Arch. Path. 1942, 33, 267. 9. Hueper, W. C. Cancer, 1957, 10, 8. 10. Hiller, A., Greif, R. L., Beckman, W. W.,
Plazin, J. J. biol. Chem.
1948, 176, 1421. 11. Varley, H. Practical Clinical Chemistry. London, 1954. 12. Peters, J. P., Van Slyke, D. D. Quantitative Clinical Chemistry; vol. 2.
London, 1932. Scand. J. clin. Lab. Invest. 1957 9, 349.
13. Closs, K.
quantitatively. The reagent is made freshly each week from a stock solution, which will keep indefinitely at room-temperature. Closs finds that, qualitatively, the method is as sensitive as Heller’s test, which will detect 7 mg. of protein per 100 ml.’4 Quantitatively the method, applied to urinary protein, appeared to agree somewhat more closely with the micro-Kjeldahl technique than is usual with turbidimetric procedures. Its usefulness in other the content of determining protein biological fluids has yet to be ascertained. This method has certain small advantages, in that the amount of fluid required is 1 ml. or less, the degree of dilution reduces the error that may arise with initially turbid urines, no heating is necessary, and interfering precipitations or colorations are rare. SURVEY OF CHILDREN
IT is a matter of common clinical experience that infants and children from poor homes do not thrive as well as the socially better favoured. But the precise effects of social conditions on physical and mental health and development are not easily defined. A study by Douglas and Blomfield 15 provides much long-awaited material. The starting-point of the work was the investigation by the Population Investigation Committee and the Royal College of Obstetricians and Gynaecologists into the circumstances and costs of all confinements in Great Britain during the first week of March, 1946. Of the 14,000 families involved in that inquiry 16 5000 children were selected for longitudinal study, and it is their lifestories up to the age of 5 that Douglas and Blomfield are now concerned with. These children spent their early years in the unsettled post-war era and have been subject to the manifold social changes of the time, not least of which was the inception of the National Health Service when they were 2. During the survey period (1946-50) housing conditions steadily improved, and many of the families moved upward in the social scale. This background has to be remembered in assessing some of the findings of the survey,. or in extrapolating conclusions for present-day needs. Poor social conditions showed differing effects according to the age of the child. In the perinatal period such conditions were associated with an increase in prematurity and neonatal death, in infancy with early and and in childhood with severe respiratory infections, of significant depression growth. At all ages the direct cause of socially determined disorders was " maternal inefficiency " with poverty, overcrowding, and large families appearing as predisposing factors. The report shows clearly that successful mothering of a large family, where the housing conditions are poor and the budget is slender, requires care, resourcefulness, education, and supportive advice. The best showing was made by the families of " black-coated workers ". As a group they are not materially better favoured than skilled workers; but by care, ability, and utilisation of child-welfare services they achieve not only favourable development for their children but also often fulfilment of their social
aspirations. Douglas and Blomfield feel that " the social and educational approach " offered by the local-authority 14. Harrison, G. A. Chemical Methods in Clinical Medicine. London, 1957. 15. Children Under Five. By J. W. B. DOUGLAS and J. M. BLOMFIELD. London: Allen & Unwin. 1958. Pp. 177. 21s. 16. Maternity in Great Britain. London, 1948. See Lancet, 1948, ii, 813.