Day-to-day variation of 24-hour intragastric acidity.

Twenty-four-hour intragastric acidity was measured continuously using an intragastric electrode in 13 normal volunteers studied four times. Subjects were studied twice in the hospital and twice as outpatients. The dietary conditions were strictly controlled and the replicate studies were compared to assess the variability of such recordings of acidity. The accuracy of the technique was assessed, and a detection limit for differences was calculated for commonly used time periods. Over 24 h, during the night, during the day, and during the evening the technique is able to detect consistent changes of pH of greater than 0.1 units. During separate 5-min periods the limits of detection were considerably greater. This study demonstrates the variability of 24-h intragastric acidity and confirms that continuous monitoring is able to detect important changes of acidity under both hospitalized and ambulant conditions.

[Urinary copper excretion from rats following administration of aliphatic and alicyclic polyamines (author's transl)]. / Die Harn-Kupferausscheidung bei Ratten nach Gabe von aliphatischen und alicyclischen Polyaminen.

The cupriuretic effectivity of tetradentate chelating agents was measured in rats and compared with that of D-penicillamine. The applied chelators are aliphatic and alicyclic tetramines and tetramine-analogous substances with two nitrogen-atoms substituted by oxygen. Urine copper excretion was measured during 24 h (and 6 and the following 18 h, respectively) after single and repeated doses over a period of 5 days. The aliphatic tetramines, triethylenetetramine (TETA, TRIEN) and BE 6184, were the most active substances. Simultaneous application of TETA and D-penicillamine does not induce a summation or potentiation of the copper elimination. After s.c. application TETA seems to be three times more effective than orally. The potency of aliphatic and alicyclic tetramines is discussed on the basis of in vitro data.

[Partition coefficients and Rm-values of cardenolides (author's transl)]. / Verteilungskoeffizienten und Rm-Werte von Cardenoliden.

Partition coefficients (P) of 48 cardenolides were determined in octanol/water. Furthermore Rm-values of most of these substances were measured in different thin-layer chromatography systems (TLC) and related to P. Regression analysis revealed that the best linear fit of the data was obtained when Rm-values from reversed-phase TLC on octanol impregnated silica-gel layer as stationary phase and methanol/water as mobile phase were correlated with log P (r = 0.91). A better correlation between these two sets of data was obtained by restricting the calculations to groups of cardenolides with similar structural features (r = 0.96-0.98). The present results are showing that Rm-values from reversed-phase TLC--a rapid and reproducible method with many advantages over the tedious measurement of P--can be used to predict P.