George F. Johnson

Digoxin Elimination in a Functionally Anephric Patient After Digoxin-specific Fab Fragment Therapy

The elimination of total digoxin after digoxin-specific Fab fragment therapy in a patient in end-stage renal disease is described. Two-component, nonlinear exponential regression of the patients total digoxin concentration data revealed biphasic elimination: a fast phase with a half-life of 43 h and a slow phase with a half-life of 330 h. Serum total digoxin concentration decreased 20% 12 h after the initiation of Fab fragment therapy. The mean serum concentrations of total digoxin and apparent total digoxin as measured by fluorescence polarization immunoassay during a 520-h period after the initiation of therapy were 18.42 and 14.77 ng/ml, respectively (n = 15). The correlation between the two measurements was good (r = 0.987). The time course of free digoxin concentration obtained after ultrafiltration at 2, 20, or 37dGC is also described. The free digoxin concentrations (n = 10) at these temperatures averaged over a 282-h period were 0.35, 0.53, and 0.82 ng/ml, respectively (p < 0.001, 2dGC vs. 37dGC).

A quantitative gas chromatographic determination of ethosuximide based on N-butylation.

A gas chromatographic procedure has been developed for the routine determination of the anticonvulsant, ethosuximide, in serum. Volatile butyl derivatives for gas chromatography were prepared by the method of R.H. Greeley (J. Chromatogr., 88 (1974) 229) using butyl iodide as the alkylating agent. This procedure yielded stable derivatives with improved chromatographic qualities over those obtained by methylation and proved superior to both on-column alkylation with tetrabutylammonium hydroxide and to silylation. The analysis requires 0.5 ml of serum and the between run precision of the assay at 40 mug/ml was 3.3%.

Pocket Guide to Biotechnology and Genetic Engineering. Rolf D. Schmid. Weinheim, Federal Republic of Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2003, 360 pp.,

This pocket guide, with beautiful color illustrations by Ruth Hammelehle, would fit in your blazer coat pocket but would more likely be found in your briefcase. As Dr. Schmid tells us in the preface, the history of biotechnology is essentially the history of civilization. Although bread and cheese are properly part of food technology and not extensively covered, beer, ethanol, and other products of fermentation are featured with emphasis on modern biotechnology. This 350-page book can be accessed …