The threshold for satiating effectiveness of psyllium in a nutrient base.

A combination of psyllium fiber with nutrients in a commercially available wafer (Fiberall-Ciba Consumer Pharmaceutical) was evaluated for its effectiveness in reducing food intake and appetite. Each of 15 nonobese healthy women received no wafers and four different amounts (39, 104, 169, and 234 kcal) of the fiber wafer with water, in a ratio of 13 kcal (and 0.565 g psyllium) wafer per 41.67 g water, 30 minutes prior to a test meal of macaroni and beef, on nonconsecutive days. Intake of the test meal and hunger ratings were both significantly reduced after intake of the two largest wafer amounts (169 and 234 kcal, respectively), in comparison with the two smaller amounts and none at all. The reduction produced by the largest amount compared to none at all was 122 kcal (about half the energy of the amount given). There were no significant differences in intake and hunger ratings among the two smaller amounts and none at all. Thus the threshold for intake reduction by this product with water lies between 104 and 169 kcal. Methodologically, this work underscores the importance of testing the satiating effects of foods at multiple levels before conclusions are drawn about their satiating effectiveness, and suggests that the threshold for significant reduction should be considered as a measure of the product's satiating effectiveness. The relative contributions of the nutrients, the fiber, and the water to the satiating effect still need to be determined.

Activity patterns in rats (Rattus norvegicus) as a function of the cost of access to four resources.

Patterns of eating, drinking, wheel running, and nesting were recorded in 2 experiments in which rats (Rattus norvegicus) lived in a laboratory environment that provided food, water, a running wheel, and a nest box. Access to each resource was contingent on the completion of a fixed ratio of bar presses and once earned remained available until the resource was not used for 10 consecutive min. In all cases an increase in the access price of a resource produced a decrease in the frequency with which the resource was accessed. This reduction in bout frequency was countered by an increase in bout size, which was compensatory for eating and nearly so for drinking, but which was only partially compensatory for wheel running. Nest bout size did not change significantly as nest price increased. The bout patterns of these 4 activities changed independently of one another, and the probabilities of behavioral transitions did not indicate strong links between any pairs of activities.

[Human recombinant erythropoietin in the treatment of anemia in patients on long-term hemodialysis]. / Ludzka rekombinowana erytropoetyna w leczeniu niedokrwistosci u chorych dlugotrwale hemodializowanych.

Recombinant human erythropoietin (EPO) was administered i.v. to anaemic patients (pts) on hemodialysis in doses from 40 to 120/IU/kg 3 times a week. 20 out of 21 pts showed an increase in hemoglobin (Hb) level above 11 g/dl after 8-12 weeks. Maintenance doses to keep Hb value about 10 g/dl varied from 2 X 40 IU/kg to 3 X 40 IU/kg per week (subcutaneous). EPO improved the well-being and physical condition in all of pts. Six pts developed rise in blood pressure and most an increase in predialysis serum potassium and urea levels during first 16 weeks of treatment.

Ambient temperature and food costs: effects on behavior patterns in rats.

Eating, drinking, wheel running, and nesting were recorded continuously in animals living in cages where they foraged for and consumed food by completing operant bar-press requirements. The ambient temperature was either 24 or 0 degrees C. Two food costs, that of initiating meals and that of pellets within meals, were separately manipulated at each temperature. Compared with room temperature, the cold temperature produced a doubling of food and water intake and a greater than twofold increase in nesting time each day. Running behavior was not altered. Regardless of temperature, the cost of initiating meals influenced the frequency and size of meals but did not affect total food intake or time spent feeding, and this cost had no effect on any other activity. As the cost of pellets within meals increased, the time spent feeding increased and there was a decline in daily food intake. The change in intake was greater at the cold temperature because in the cold the rats did not increase daily feeding time sufficiently to maintain intake as pellet cost increased. Such an increase in feeding time would have required that less time be spent in one of the other activities.

Changes in macronutrient selection as a function of dietary tryptophan.

It has been hypothesized that the serotonergic system is involved in the regulation of carbohydrate and/or protein intake. Tests of this hypothesis using added dietary tryptophan and diets varying in the ratio of carbohydrate/protein resulted in depressed intakes of high carbohydrate/low protein diets, elevated intakes of low carbohydrate/high protein diets, and a reduction of total caloric intake. The present studies gave rats increased options for adjusting to added tryptophan by providing them with separate sources of protein, carbohydrate, and fat. The results showed the expected decrease in carbohydrate intake, but also increases in fat intake and, to a lesser extent, protein intake. Total caloric intake was conserved. Hypothalamic concentrations of serotonin and 5-hydroxyindole acetic acid indicated increased activity of the serotonergic system. These results lend support to serotonin's involvement in nutrient selection, in that carbohydrate consumption decreased in response to tryptophan loading, but indicate that other nutrients may also be affected. Given the option of altering fat intake, the animals maintained a constant caloric intake despite the reduction of carbohydrate consumption.