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Biomedical subjects

K Keller

Publications and source records attributed to K Keller.

At least 145 records · Page 8Linked to original sources
PubMed1976

Glycolysis and glycogen metabolism after inhibition of hexose monophosphate pathway in C6-GLIAL cells.

1. 6-Aminonicotinamide (0.01 mg/ml) leads to a strong accumulation of 6-PG in C6 glial cells after 24h. 2. The accumulated 6-PG is dephosphorylated to gluconate which easily permeates the cell membrane. Extracellular gluconate is formed at a rate of 12% of the total glucose consumption. 3. 6-PG as competitive inhibitor of the PG1 caused a reduction of the glycolytic flux of about 40%. 4. The reduced glycolytic flux lowers the ATP concentration under anaerobic conditions to 75% of the controls. 5. The glycogen content after 6-AN is increased by 50%, probably by the activation of the glycogen synthetase due to the higher Glc 6-P concentration. 6. The fibroblast-like morphology of the C6 cell line has typically changed under 6-aminonicotinamide.

6-Aminonicotinamide↗
PubMed1976

The stages of acquisition in stimulus fading.

Pigeons were exposed to a stimulus fading procedure in which control of responding was transferred from red and black stimuli to lines of different angular orientation. After superimposing one line on the red stimulus and the other line on the black stimulus, the intensity of the lines was gradually increased and that of the red stimulus was gradually reduced. Probes consisting of red and line stimuli presented separately were used during the course of fading to assess control exerted by each element of the compound. As the lines were faded in, they did not acquire control of responding. As red was faded out, control of responding was acquired first by the lower intensity red stimuli in combination with the line stimulus, and finally by the angular orientation of the lines. Probes also determined the point at which the line stimuli, presented alone, would maintain a high degree of stimulus control. The results demonstrated that new stimuli in fading acquire dimensional control of responding in two sequential stages. Acquisition of stimulus control in fading was explained in terms of attenuation of stimulus blocking.

Journal Article↗
PubMed1975

A profile of clinical nutrition knowledge among physicians and medical students.

The clinical nutritional knowledge of medical students and practicing physicians was assessed. Overall, nutrition knowledge was modest. However, there were substantial variations in knowledge among closely related topics. Knowledge often was highest among nutrition topics which have received the most publicity in the popular press. The nutrition knowledge profile suggests that medical students and physicians learn about nutrition haphazardly and are highly dependent for their knowledge on nonprofessional literature.

Diet↗
PubMed1975

The public seminar as a nutrition education approach. An evaluation.

A health seminar seemed to modify knowledge, attitudes, and reported behavior of a self-selected audience which was already well informed and motivated to change. Therefore, the health seminar appears to be a useful educational approach in this context. The question remains: How can those who are neither informed nor motivated be reached? This study suggests that the public seminar may not be an efficient vehicle for this purpose.

Attitude to Health↗
PubMed1975

The survey in family practice research.

The survey is a method that can be employed in family practice research. It is an adaptable tool that can be used with good results by those not sophisticated in research. General guidelines for survey research are discussed in this article, and an illustrative example of a survey conducted by the authors is presented.

Family Practice↗
PubMed1974

The role of elicited responding in behavioral contrast.

An attempt was made to separate operant and elicited pecks occurring in multiple schedules of food reinforcement by moving the component stimuli to a second key, upon which pecks had no effect. The operant key stimulus was constant, regardless of the reinforcement schedule in effect. Experiments included two- and three-component multiple schedules and a comparison of the single-key and the two-key procedures. In general, conditions that typically produce positive contrast in single-key procedures reduced responding to the constant-stimulus key (induction) and increased responding to the component-stimulus key (contrast) in the two-key procedure. The results were interpreted as supporting the contention that two response classes, operant and elicited, are present in standard multiple schedules. In addition, elicited responses were strongly implicated in contrast phenomena.

Journal Article↗
PubMed1973

Degradation of cellular deoxyribonucleic acid after gamma irradiation of spheroplasted Escherichia coli CR thy- cells.

Gamma-ray-irradiated Escherichia coli CR thy(-) cells and spheroplasts, prelabeled with (14)C-thymine, were assayed for acid-insoluble activity as a function of incubation time after irradiation. Under similar irradiation and incubation conditions, degradation profiles of cells and spheroplasts were virtually identical. Similar results were found for cells and protoplasts irradiated in the presence of rifampin (20 mug/ml). These results suggest that postirradiation deoxyribonucleic acid degradation enzymes are probably not loosely localized in the periplasm, unlike endonuclease I.

Carbon Radioisotopes↗