Twenty years of success and still growing.
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Education, Nursing, Baccalaureate↗
Biomedical subjects
E Van Doren
Publications and source records attributed to E Van Doren.
Membrane potential of erythrocytic stages of Plasmodium chabaudi free of the host cell membrane.
Free parasites were isolated from Plasmodium chabaudi-infected rat erythrocytes by N2-cavitation and purified on Percoll gradients. The membrane potential of the free parasites determined from the transmembrane distribution of the lipophilic cation, tetraphenylphosphonium, was -93 +/- 10 mV for late stage parasites and -90 +/- 3 mV for ring forms. Studies with intact infected erythrocytes demonstrated that the membrane potential of ring forms was much smaller compared to late trophozoites and schizonts and thus the present findings with free parasites suggest that host cell cytoplasmic factors may determine the magnitude of the parasite membrane potential. Both extracellular pH and [Na+] were found to modify the membrane potential of free parasites. Electrogenic protonophores, the H+-ATPase inhibitor dicyclohexylcarbodiimide and orthovanadate collapsed the potential of free parasites. Ouabain (or its membrane permeant derivative, strophanthidin), and oligomycin were without effect. These inhibitor studies suggest that an electrogenic H+-ATPase similar to that found in yeast generates in part the membrane potential of malaria parasites. Using weak acid distribution or a pH sensitive fluorescent dye, it was demonstrated that free parasites maintain an alkaline intracellular pH at extracellular pH greater than 6.5. The pH gradient was partially collapsed by orthovanadate or dicyclohexylcarbodiimide and by substitution of Na+ for K+ in the suspending buffer. The H+-ATPase and K+:H+ exchange may therefore both contribute to regulation of intracellular pH in Plasmodium.
Animals↗
Ca2+ metabolism of Plasmodia-infected erythrocytes.
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Adenosine Triphosphatases↗
Reducing restraints: where to start.
To begin a restraint reduction program at a large neuropsychiatric Veterans Affairs medical center, nursing educators examined perceptions of and knowledge about restraint use among 113 nursing staff members employed on one acute, two intermediate, and five long-term care units. Strumpf and Evans' (1988) Perceptions of Restraint Use Questionnaire, a knowledge test, and questions about personal characteristics were used. Top reasons for restraint use identified were to prevent pulling on an intravenous line, to prevent breaking open sutures, and to protect from a fall. Although knowledge scores were high, they did not correlate significantly with ability to suggest alternatives. Respondents viewed restraint use as a somewhat important intervention. Statistically significant differences were found between level of practice and number of alternatives listed, knowledge score, and personal perception score. Implications for nursing educators embarking on a restraint reduction program are discussed including myths and quality-of-life issues.
Adult↗