Pharmacologic amino acid acylation in the acute hyperammonemia of propionic acidemia.

An infant with propionic acidemia presented at one month of age with hyperammonemic coma. Treatment by two double-volume exchange transfusions did not have an appreciable effect, but hemodialysis led to a substantial reduction of the serum concentration of ammonia on two occasions. Nevertheless, continued therapy with sodium benzoate, arginine-HCl, carnitine and lactulose did not have any observable effect on the blood concentration of ammonia.

Computer-based video analysis of cerebral arterial geometry using the natural fluorescence of the arterial wall and contrast enhancement techniques.

The walls of mammalian arteries fluoresce with ultraviolet excitation in the wavelength range of 350-400 nm. We are using this property of natural fluorescence in conjunction with episcopic fluorescence microscopy, frozen section techniques, selective contrast enhancement, and a semi-automatic computer-based video analysis system to obtain dimensional data and 3-D coordinate maps of cerebral bifurcation geometry. The computer-video analysis system, comprised of commercially available video components, a Cromemco Z2D Computer, and electronic components built in our lab has a resolution of +/- 1/256 mm at full-screen magnification.