Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

[EX Q]: Abstract: The effects of at least three doses of each of five orally administered progestins on estrogen-primed, postmenopausal endometrial biochemistry and morphologic features were analyzed. The progestins tested were norethindrone, medroxyprogesterone acetate (MPA), norgestrel, dydrogesterone, and progesterone. The dose required to elicit responses similar to those seen in premenopausal, secretory endometria was assessed for each of the parameters measured, and the relative potencies were calculated. Potencies, relative to a value of 1 for norethindrone, are L norgestrel 8 (D/L norgestrel 4), MPA 0.1, dydrogesterone 0.02, and progesterone 0.002. The dose of norethindrone required to elicit secretory phase activity was about 0.35 mg/day. These values agree with published data obtained with the use of different methods (delay of menstruation in premenopausal women, endometrial histologic features of estrogen-primed, ovariectomized women).
[EX A]: Administration, Oral

[EX Q]: Abstract: To investigate the mechanism of ventricular arrhythmias induced by epinephrine in dogs with hypokalemia, 30 adult mongrel dogs were separated into a control group (n = 13) and a hypokalemia group (n = 17). In the hypokalemia group, sodium polystyrene sulfonate (5 g/kg body weight) was infused into the colon. In both groups, the serum concentrations of sodium, potassium and calcium were measured every 15 minutes for 60 minutes. The mean (+/- standard deviation) serum potassium level of the hypokalemia group decreased significantly from 3.81 +/- 0.21 to 2.92 +/- 0.36 mEq/liter; there were no significant changes in other electrolytes. After 60 minutes, epinephrine (10 micrograms/kg) was injected intravenously in the hypokalemia and control groups, and the arrhythmia ratio (the number of ventricular ectopic beats divided by the total heart rate) was calculated for 5 minutes. Each group was further classified into subgroups of dogs with an arrhythmia ratio higher or lower than 10%. An arrhythmia ratio over 10% was observed in 7.7% of the control group and 53% of the hypokalemia group. Immediately after 5 minutes of epinephrine injection, myocardial mitochondria and plasma membrane fraction were prepared from each group. Mitochondrial calcium content and phospholipase activity of plasma membrane fraction were determined. Significant increases in both mitochondrial calcium content and phospholipase activity were observed in the dogs with hypokalemia and an arrhythmia ratio greater than 10%.(ABSTRACT TRUNCATED AT 250 WORDS)
[EX A]: Animal

[EX Q]: Abstract: The concentration of FFA in normal human plasma in vivo generally ranges between 0.2 and 0.7 meq/liter; slightly higher concentrations have occasionally been reported in patients who are seriously ill. To determine whether such FFA concentrations may increase the concentration of free T4 in serum, we added increasing amounts of oleic acid to pooled normal human serum (with known FFA content) and measured free T4 by equilibrium dialysis. Total FFA up to 3 meq/liter in normal serum, representing an FFA to albumin molar ratio of about 5:1, had little or no effect on the free T4 concentration, while higher FFA concentrations progressively increased free T4. This same molar ratio of FFA to albumin had to be exceeded to cause a significant increase in the free T4 concentration in diluted serum and in serum from patients with nonthyroid illness. Serum from which more than 95% of the albumin had been removed by chromatography with Affi-Gel blue was much more sensitive to the effects of FFA on free T4. This enhanced sensitivity was reversed by readdition of albumin to the serum, and the addition of albumin to normal serum resulted in diminished effects of FFA on free T4. These results indicate the following: physiological concentrations of FFA do not significantly increase the free T4 concentration in normal human serum; when FFA reach supraphysiological concentrations in serum (in vitro) and the higher affinity FFA-binding sites on albumin become saturated (apparently at an FFA to albumin molar ratio of approximately 5:1), the excess FFA interact with other serum proteins, including thyroid hormone-binding globulin, and thereby increase the free T4 concentration; the concentration of albumin (or other FFA binders) must be considered when evaluating the observed effects of FFA. To explore the relevance of these findings to the hypothesis that FFA may inhibit the binding of T4 to plasma proteins in patients with nonthyroid illness, we measured plasma FFA concentrations in 11 severely ill patients hospitalized in the intensive care unit. We found a mean plasma FFA concentration of 0.45 +/- 0.11 (+/- SEM) mEq/liter and a mean serum albumin concentration of 2.39 +/- 0.29 g/dl in these patients. Their mean plasma FFA to albumin molar ratio was 1.53 +/- 0.41. Since the FFA to albumin molar ratio must exceed about approximately 5:1 before a significant increase in the serum free T4 concentration occurs, these results suggest that FFA do not commonly influence the circulating free T4 concentration in vivo, even in severely ill patients.
[EX A]:
Fatty Acids, Nonesterified