Biomedical subjects

C A Baumgardner

Publications and source records attributed to C A Baumgardner.

6 recordsLinked to original sources

PubMed1995

The toxicities of short-chain primary alcohols and the accumulation of storage bodies in the larval fat body of Drosophila melanogaster.

In terms of the LD50 values for alcohols, third-instar wild-type larvae of Drosophila melanogaster had a greater tolerance to ethanol, n-propanol and n-butanol than alcohol dehydrogenase (ADH)-deficient larvae. The tolerances of the two strains to methanol were similar. Methanol, ethanol, n-propanol and n-butanol all induced higher ADH activity in wild-type larvae. Ethanol, n-propanol, methanol and n-butanol slowed the growth for ADH-deficient larvae, whereas only methanol had this effect on wild-type larvae. The proportion of wild-type pupae to eclose was increased by n-butanol, n-propanol and ethanol. Cytometric methods to measure the densities of storage bodies--glycogen rosettes, protein bodies and lipid droplets--in fat body cells indicated that all of the test alcohols exerted some negative influence on the accumulation of at least one type of storage body. Analyses of total protein, glycogen and acylglycerols indicated that ethanol and n-butanol were associated with an accumulation of acylglycerols in both wild-type and ADH-deficient larvae; whereas, the other test alcohols resulted in low glycogen and protein concentrations in both test strains. The short-chain primary alcohols may in part be toxic to larvae because of disruptions in metabolism that lead to reductions in one or more kinds of storage bodies in the larval fat body.

1-Butanol↗

PubMed1995

Very long-chain fatty acids change the ethanol tolerance of Drosophila melanogaster larvae.

This research tested the hypothesis that long-chain saturated fatty acids increase the order of cell membranes of an organism and minimize the detrimental fluidizing effects of ethanol. Unsaturated fatty acids increase membrane fluidity and are unlikely to increase the ethanol tolerance of the organism. Both a fatty acid-free medium and media supplemented with very long-chain fatty acids (20 or more carbons) were fed to wild-type larvae of Drosophila melanogaster; larvae were then transferred to media with or without ethanol to test for effects of the fatty acids on ethanol tolerance. Ethanol decreased the percent of larvae to pupate, and lengthened larval development time. However, the percentage of pupae to reach the adult stage and the weight of adult males increased when the larvae were fed ethanol. The very long-chain, unsaturated fatty acids, arachidonic acid [20:4(n-6)] and docosatetraenoic acid [22:4(n-6)], were associated with increased larval mortality when administered in a medium supplemented with ethanol. Arachidic acid (20:0) increased the percentage of larvae to pupate under ethanol stress, decreased the development time and increased the adult weight in the presence and absence of ethanol. Behenic acid (22:0) was not effectively incorporated into phospholipids and had little effect on growth traits. Thus, the experimental results were consistent with the hypothesis.

Alcohol Dehydrogenase↗

PubMed1994

Management development: preparing nurse managers for the future. Part 1, Program model.

Nurse executives need to develop programs to help nurse managers meet rapidly changing role expectations and prepare for new healthcare challenges. This two-part series reports on one such program for nurse managers at The Johns Hopkins Hospital. Part 1 describes the program model, its conceptual framework, and its various components. Part 2 will present an in-depth evaluation of the program and recommendations for future development.

Baltimore↗

PubMed1993

Effects of nail polish on microbial growth of fingernails. Dispelling sacred cows.

Nail polish worn on short, healthy nails does not appear to be associated with increased microbial counts on the fingernails. Additional studies to examine the effect of wearing nail polish on other aspects of hand hygiene may be warranted, however.

Adult↗

PubMed1990

Effect of dietary carbohydrates and ethanol on expression of genes encoding sn-glycerol-3-phosphate dehydrogenase, aldolase, and phosphoglycerate kinase in Drosophila larvae.

The genes encoding glycolytic enzymes in Drosophila form a group of functionally related genes that may be coordinately regulated and thus controlled by common factors. We have examined the effect of dietary carbohydrates and ethanol on expression of the genes encoding glycerol-3-phosphate dehydrogenase (GPDH), aldolase (ALD), and phosphoglycerate kinase (PGK) in D. melanogaster larvae. GPDH activity and transcript abundance increased in response to ethanol and additional amounts of several different carbohydrates. In addition, the levels of two alternatively processed Gpdh transcripts were differentially regulated by the treatments. The nutritional conditions tested had little or no effect on the activities and transcript levels of ALD and PGK. These results indicate that changes in dietary conditions affect expression of specific genes and do not evoke a general response from genes involved in cellular metabolism. The observation that dietary carbohydrates and ethanol increase Gpdh expression without affecting expression of Ald and Pgk reinforces previous suggestions that dietary carbon can be diverted by GPDH from glycolytic catabolism into lipid biosynthesis.

Animals↗

PubMedDate not supplied

Management development: preparing nurse managers for the future. Part 2, program evaluation.

In Part 1 of this two-part series (JONA, June 1994), the authors described the factors that influenced the need for a nurse manager development program and the conceptual model used to plan and implement that program at The Johns Hopkins Hospital. In Part, 2 they describe the program evaluation and implications for future work.

Adult↗