Derivatives of 1-naphthyl ethylenediamine dihydrochloride for standardization of direct-bilirubin assays done with the Technicon "SMAC".
The Jendrassik--Groff assay for direct bilirubin was adapted for analysis rates of 150/h on the Technicon "SMAC" continuous-flow analyzer. This requires development of a standard that is compatible with the other 19 channels on this analyzer. N-1-Naphthyl ethylenediamine dihydrochloride has been used for standardization of direct bilirubin assays, but we found it to be unsuitable because values for potassium are falsely elevated when potassium is determined with a valinomycin ion-selective electrode. This interference can be eliminated by alkylating the aliphatic amine group in the standard. The resulting compounds undergo the coupling reaction in the same way as the original compound and function equally well as standards for the direct bilirubin reaction. The only limitation of these analogs is their decreased solubility at physiological pH in some cases. Thus only certain alkyl groups are suitable.
Determination of direct-reacting bilirubin on the SMA 12-60.
1. An improved method for the determination of direct-reacting bilirubin on the Technicon SMA 12/60 AutoAnalyzer is presented. 2. The addition of a blank channel to the direct-reacting bilirubin manifold improves the accuracy and precision of the determination. 3. The use of N-1-naphthyl ethylenediamine dihydrochloride as a secondary standard for direct-reacting bilirubin is suggested. 4. The effect of N-1-naphthyl ethylenediamine dihydrochloride on eighteen determinations available as standard methods on the Technicon SMA 12/60 AutoAnalyzer is presented.
BIOLOGY OF BILE PIGMENTS
The Development of Tropical and Sub-tropical Countries: with Particular Reference to Africa. Edited by A. Leslie Banks, M.A., M.S., F.R.C.P., D.P.H. (Pp. 217+xvi; illustrated. 18s.) London: Edward Arnold Ltd. 1954. This book should be read and carefully considered by all concerned with tropical Africa, be they doctors, teachers, Civil Servants, industrialists, or politicians. It is a record of the proceedings of an informal seminar held at Cambridge in 1953 on the development of tropical and sub-tropical countries with particular reference to Africa, and in its pages are reflected the wisdom of 32 distinguished contributors. Change there is inevitable, for, as Dr. J. A. Logan pointed out, " Because of world-wide economic and social forces, Africa is caught up in the relentless wheel of ' progress.' " This change must therefore be faced and channelled into acceptable directions. By Western standards Africa is underdeveloped, but desirable development in any one direction may have far-reaching and possibly undesirable effects in other directions. Perhaps the greatest value of the serninar lay in helping to limit such undesirable change by bringing together views and experiences of experts in different fields and facilitating integration and discussion of the broad principles of further development. The seminar was fortunate in having Dr. K. A. Busia, of the Department of Sociology, University College of the Gold Coast, to describe from the African viewpoint some of the problems inherent in development. He stressed differences in the way Africans, as compared with Europeans, interpret life. Thus "when an African gets an additional sum of money it is not invested as an economist might advise . . . he probably spends it in having a big funeral for a relation who died three, four, or five years ago. Or he may spend it, when he is living in an overcrowded room and is starving himself and his family, in order that he may get five, six, or seven extra changes of clothing, because prestige is measured in those terms." Appreciation of such points is important if false conclusions are to be avoided. Thus malnutrition in Africans is not necessarily an expression of poverty. From consideration of such matters the seminar proceeded to study technological development, power and water, food and its production, health, welfare, education, and possible future lines of action. A comprehensive programme, and each discussion embodied the results of much thought and experience. Many of the points made are controversial, but all merit careful consideration. The book cannot fail not only to have an important impact on future development in Africa but also to stimulate and provoke discussion among all who read it. A. W. WOODRUFF.