Biomedical subjects

A A Turner

Publications and source records attributed to A A Turner.

5 recordsLinked to original sources

PubMed1998

Standard versus modified bio-electrical impedance analysis on reactance measurements.

The purpose of this investigation was to compare score consistency of the observed reactance measurements for total body composition bio-electrical impedance analysis (BIA), using standard and modified electrode placement procedures. Subjects were 80 military males (19-56 years) who volunteered from Elmendorf Air Force Base, Anchorage, Alaska. The RJL Systems Spectrum Lightweight Instrument was used. RJL's rules were followed for standard procedure, and the proximal electrode sites were changed for the modified procedure. The hand and foot proximal electrodes were placed in the center of the antecubital space and popliteal fossa, respectively. The study used a four-faceted crossed, random effects design. The object of measurement was person, and facets of generalization were day, occasion, and trial. Data were analyzed independently for each electrode placement procedure. The analysis revealed: 1) person contributed the largest source of systematic variance, as expected, and 2) person x day interaction accounted for the significant percentage of unwanted measurement error for both electrode placement procedures. The relative and absolute coefficients of the G-studies (80 persons x 2 days x 2 occasions x 3 trials) were 0.86 for standard and 0.83 for modified. The D-studies (111, 211, 311, and 511) revealed relative and absolute coefficients which ranged from 0.75 to 0.94 for standard, 0.67 to 0.91 for relative, and 0.67 to 0.90 absolute for modified. The G-coefficients (G study and D studies) for reactance measurements showed the standard electrode placement procedure produced more consistent scores than the modified proximal electrode placement procedure. In conclusion, generalizability analysis on reactance scores demonstrated the standard electrode placement procedure still to be superior over the modified electrode placement procedure.

Adolescent↗

PubMed1991

Personality profiles of Iditarod mushers as compared by finish group.

This study uses a personality profile questionnaire to determine what it is about a person's character that makes them unique to their finish place in the Iditarod Trail Sled Dog Race using data collected from 1988 and 1989. It is the purpose of this study to determine differences in personality that make a musher a top ten finisher as opposed to those who finished in other groups. Mushers were divided into five groups: 1) top ten, 2) 11 to 20, 3) 21 to 30, 4) 31 to last, and 5) scratches. Data was subjected to an analysis of variance (ANOVA) and a Pearson Product-Moment Correlation to determine if any significant distinctions occurred among these groups. A main effect is found in Factor E, Factor F, Factor L, and Factor Q2. In Factor E, Group 1 (top ten finishers) was found to be more aggressive. This group is also more enthusiastic (Factor F). Top mushers are more suspicious and hard to fool (whereas those who finish last are more trusting [Factor L]). Top ten finishers are more group-oriented than the rest of the mushers, inferring that they get along with others and are more helping (Factor Q2). These data suggest that to place in the top ten pack of Iditarod mushers, one must be aggressive, enthusiastic, and calculating.

Adult↗

PubMed1990

Interferon-gamma alters expression of endothelial cell-surface glycosphingolipids.

Our previous work on human endothelial cell (EC) glycosphingolipids (GSLs) demonstrated that these cells contain a large diversity of GSLs, predominantly with lacto core structures. In order to evaluate the role of GSLs as EC antigens and receptors, we investigated their cell-surface expression on confluent EC monolayers and ECs activated by interferon-gamma (IFN-gamma) and interleukin-1 (IL-1). IFN-gamma activation of endothelial cells resulted in a small change in GSL composition, but greatly increased surface expression of gangliosides and decreased surface expression of neutral GSLs. In particular, surface expression of the major neutral GSL, globoside, decreased three- to fourfold as measured both by galactose oxidase labeling and by binding of the anti-globoside monoclonal antibody 9G7. IFN-gamma did not significantly alter the total cell content of globoside, as measured by metabolic labeling, but rather altered the ratio of accessible cell surface to intracellular globoside. Two mechanisms appear to contribute to the decreased cell-surface globoside expression. IFN-gamma treatment increased the relative proportion of intracellular globoside which is associated with the cell cytoskeleton. IFN-gamma treatment also caused more of the cell-surface globoside to be inaccessible to antibody, and both neuraminidase and trypsin treatment of the cells increased globoside accessibility. IL-1 treatment increased total cell GSL content, but did not alter GSL composition or cell-surface binding by six anti-carbohydrate antibodies. The specific modulation of cell-surface GSLs by IFN-gamma suggests that GSLs may play a role in the altered adhesive and receptor activities of IFN-gamma-activated ECs.

Antibodies↗

PubMed1978

Contact reactions influencing cell locomotion of a mouse sarcoma in culture.

An investigation of the behaviour of cells of the mouse transplantable sarcoma S180 in culture by time-lapse cinematography has been made to determine how the spreading of a population from an explant is affected by contact reactions between the sarcoma cells; and how the invasion of a fibroblast population is affected by contact reactions with the fibroblasts. Although the sarcoma cells show a form of contact inhibition to each other, this has little influence on the spreading of a population, which is brought about very largely by diffusive movement, in sharp contrast to the spreading of a fibroblast population. The invasion of a fibroblast population by S180 cells takes place as a consequence of defective contact inhibition; though contact inhibition (but not contact paralysis) of the S180 cells has an appreciable incidence. During invasion the S180 cells, though moving on the exposed surfaces of the fibroblasts, may be largely using the collagen substratum between the fibroblasts for their locomotion. The arrangement of the fibroblasts produces some degree of contact guidance of the sarcoma cells.

Animals↗

PubMedDate not supplied

Effects of orthostatic fluid shifts on bioelectrical impedance measurements.

This study analyzes the effect of orthostatic fluid shift caused by body postural changes on the reliability and stability of bioelectrical impedance. It has been found that following a fluid distribution perturbation caused by postural changes, impedance values change for a period of time that can be longer than the measurement time. Based on these preliminary measurements, it is recommended that new measurement protocols for bioelectrical impedance be developed in order to minimize perturbations on existing fluid distribution, thus increasing the reliability of bioelectrical impedance data.

Body Composition↗