The 14C carbonate method for the direct measurement of the synthesis rates of liver-produced plasma proteins (McFarlane, 1963) is a valuable new tecnnique for the study of protein metabolism in gastrointestinal diseases. It is the purpose of this communication to describe a study in which this technique has been applied to investigate the mechanism of the hypoproteinaemia and disordered protein metabolism which occur in the stagant loop syndrome. METHODSSamples of fasting jejunal contents were obtained using the capsule designed by Shiner, Waters, and Gray (1963) and the samples were cultured both aerobically and anaerobically. Viable bacterial counts were made using serial dilutions (Miles, Misra, and Irwin, 1938). Urinary indicans were measured by the method of Curzon and Walsh (1962).The distribution ratio and fractional and absolute catabolic rates of albumin were determined by the method of graphical analysis (Matthews, 1957) using human serum albumin (Behringwerke) which had been labelled with 1251 by a modification of the iodine monochloride technique (McFarlane, 1958). Plasma volumes, used in calculating the intravascular pools of the plasma proteins, were measured using 131I albumin.Concentrations of the plasma aminoacids were estimated using a Technicon amino-acid AutoAnalyzer.Absolute synthesis rates of albumin and fibrinogen were measured simultaneously by a modification of the 14C carbonate method (McFarlane, 1963). Urea pool sizes and urea synthesis rates were calculated from the curve of clearance from the plasma and the urinary excretion of a known mass of 13C urea (63.5 atoms% excess), administered intravenously (Craigie, Jones, Rosenoer, and Smallwood, 1967). The 13C atoms%7, excess of urea in plasma and urine samples were determined by mass spectrometry in the

In 1935 Tiselius, using the apparatus he had devised in 1930, demonstrated that human serum globulin fell into three reasonably defined groups based on their electrophoretic mobilities. For the next 15 years a steady flood of papers reported the fluctuations of albumin and the globulins in young and old, in health and disease, as disclosed by analyses carried out using Tiselius apparatus with and without the numerous minor modifications which were introduced.In spite of brilliant efforts at simplification it was evident that the method, because of its relative complexity, could never have widespread use in routine clinical chemistry. In 1950 three groups of workers, among them Tiselius himself, described methods which indicated that, using filter paper as a matrix, a relatively cheap and rapid method could be evolved of obtaining a rough analysis of the serum proteins akin to the analysis obtained by the classical technique.The method required no more than 0.5 ml. of serum, and though estimates of the total protein concentration would still have to be made by other means, it was conceivable that this simple technique would dispense with the tedious salt fractionation and subsequent analyses required heretofore to obtain the albumin/globulin ratio.The last four years have produced a spate of papers devoted to the description of modifications in methods of separation and analysis with numerous technical and mathematical tricks for improving the correlation of the results with the substantial body of data already obtained with the classical technique. With few notable exceptions scant attention was paid to the fundamental principles underlying the technique or to the points in which their application to it differed from the classical procedure.As paper succeeded paper it became increasingly evident that except within fairly wide limits the two methods were not quantitatively comparable.Even worse, because of lack of time spent on a consideration of the basic principles involved, G it seemed probable that differing techniques for the production of " electrophoretograms " were not comparable among themselves.One was faced with the prospect of scores of laboratories turning out hundreds of results year by year; each group, because of deviations in technique unappreciated and therefore unrecorded, differing to an unknown extent one from the other. The clinical chemical chaos that could arise demanded a reassessment of the situation in the hope that workers in the field would stop, think, and start again.Electrokinetic phenomena, as the derivation of the word implies, are concerned with the

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Lod scores for linkage of the albumin and Gc loci have been calculated for 21 pedigrees in which six different types of albumin variants are segregating. There is no evidence for heterogeneity in the linkage distance among the different types of variants. The most likely value for the recombination fraction in the combined data is at Ô = 0.023.

In attempts to develop quantitative techniques for the analysis of serum proteins separated by electrophoresis on filter paper, many workers have estimated the amount of dye taken up by the different protein fractions after staining. WVhen comparisons have been made with analysis by the classical