Factors affecting aspartimide formation, such as protecting groups, acidity, basicity, and temperature, were studied using the model tetrapeptide, Glu-AspGly-Thr. The aspartyl carboxyl side chain in this tetrapeptide was either free or protected as a benzyl or cyclohexyl ester. Our results showed that the cyclohexyl ester led to far less aspartimide formation during acidic or tertiary amine tre...

Whichever dialysis therapy is used, there is a similar need for correcting the acid base balance. The most important tool for this is the buffer in the dialysis fluid and, when using convective therapies, also in the substitution solution. The buffer source in all modern versions of these therapies should be bicarbonate. The more efficient the dialysis treatment in terms of small solute transpo...

Purified preparations of cattle rhodopsin have been titrated to various pH, irradiated, and the pH changes followed thereafter until completed. In this way we have obtained the titration curves of rhodopsin, of the immediate product of irradiation, measured within 30 seconds; and of the final product of irradiation (opsin). The rhodopsin preparations display about 54 titratable groups per mole ...

The reaction, the osmotic pressure, and the volume relationships of the body fluids are closely dependent on the properly regulated acid-base equilibrium. We have attempted to work out some of the regulatory mechanisms for the preservat.ion of acidbase equilibrium during the process of heavy sweating in ways analogous to those employed in the many similar studies of blood and urine. The changes...

In the normal, healthy individual the acid-base balance within the body is remarkably constant. For example, arterial blood, drawn from healthy individuals at sea level, will show that, in over 95% of the individuals, the pH of the blood is between 7.35 and 7.45. Furthermore, the pC02 will be maintained between 35 and 48 mmHg while the bicarbonate concentration will be between 23 and 28 mEq/L. ...

Switching in acidosis of hepatic nitrogen disposal from urea synthesis to NH4 + and net glutamine production was demonstrated in the isolated perfused livers of starved male Wistar rats. Lactate was preferred to glucose as the substrate for the carbon skeleton of glutamine synthesized over the pH range 6.9-7.5. This is necessary if the switch away from a proton-producing process (ureagenesis) i...

The use of fluorescent nucleic acid base analogues is becoming increasingly important in the fields of biology, biochemistry and biophysical chemistry as well as in the field of DNA nanotechnology. The advantage of being able to incorporate a fluorescent probe molecule close to the site of examination in the nucleic acid-containing system of interest with merely a minimal perturbation to the na...

SINCE the introduction of external cardiac massage the technique and results of cardiac resuscitation have received much attention, but less information is available on the effect of cardiac arrest on respiration and circulation. The authors, who provided a resuscitation service for a general hospital, were particularly interested in these aspects and in thirty-eight of the first 100 patients t...