Search PubMed⌕ Search

Biomedical subjects

U E Westfall

Publications and source records attributed to U E Westfall.

12 recordsLinked to original sources
PubMed2000

How enteral feeding options influence corticosterone patterns in rats.

Even with all the nutritional research conducted to date, it is not clear which enteral nutrition delivery and composition options are most physiologically sound. Glucocorticoid temporal patterns are reported to be shifted or disrupted with restricted feeding schedules, but because of intermittent sampling, temporal patterns have not been completely depicted. The purpose of this study was to characterize corticosterone temporal patterns while systematically varying selected enteral feeding options in a well-established nutritional animal model. A 2 x 2 x 2 x 2 randomized block experimental design was used in which enteral feeding schedules, delivery methods, kilocalorie levels (kcal), and fiber contents were systematically varied in rats (n = 80), and plasma corticosterone was measured by 125I radioimmunoassay. Blood samples were drawn hourly over 24 h. With cosinor analysis, 24-h and 12-h corticosterone rhythmic components were tested in each feeding group. Five of 16 feeding groups had a significant (p < or = 0.05) 24-h rhythmic component, and 3 more showed a trend (p > 0.05 < 0.10); 7 of these groups were on 24-h feeding schedules. When rhythmic components were detectable, groups receiving high-fiber formula displayed more uniform rhythm characteristics than did no-fiber groups. Only 1 group had a significant 12-h rhythmic component, and 1 showed a trend. Both were on 12-h, high-fiber restricted kcal feedings. In this small animal sample, no one enteral feeding option guaranteed a 24-h corticosterone pattern. The option coming closest was formula delivered on a 24-h schedule. This temporal pattern is one aspect to consider in enteral nutrition. The underlying mechanisms have yet to be elucidated.

Analysis of Variance↗
PubMed1999

Organ and tissue weight presentation in rat populations.

Multiple ways of reporting organ weights are sources of confusion in literature. This study was designed to determine if there is a linear relationship between body weights and selected organ and tissue weights in groups of rats after different liquid feeding options. A randomized 2 x 2 x 2 factorial, randomized block design was used with 40 postpubescent male rats with two levels of feeding schedules, kilocalorie levels, and fiber contents. In addition to a skeletal muscle, 13 abdominal and thoracic organs or tissues were weighed. Pearson product-moment correlation coefficients and regression analyses were completed to determine the relationship between these weights and the final body weights. Findings support the need to use different approaches in order to accurately report various organ and tissue weights.

Age Factors↗
PubMed1993

Animals, care, and nursing research.

These multiple measures of health were positive and encouraging. It was possible to integrate nursing actions into protocols for this long-term study. It is the author's belief that by strengthening the humane care and handling of animals the study results can more accurately reflect the discipline of nursing. Through such efforts, discipline-specific findings could be strengthened when an animal model is used, particularly in long-term or survival nursing research.

Animal Welfare↗
PubMed1992

Nursing chronotherapeutics: a conceptual framework.

Nurses frequently make decisions about when treatments and actions are performed. The nursing concern driving this review is the timing of nursing activities to optimize desired and minimize untoward effects. A nursing conceptual framework is proposed that highlights individual and environmental factors, as they relate to rhythmic responses; as well as places within the framework for nursing actions based on customary and usual temporal patterns.

Biological Clocks↗
PubMed1986

Activating clinical inferences: a component of diagnostic reasoning in nursing.

In this exploratory study, nursing inferences were examined within a framework of information processing theory. Verbal responses to a patient simulation by 28 nursing students and 15 practicing nurses were used as data. Six different categories of inferences were identified. Inferences most frequently activated across educational levels were those about immediate situational concerns. Practicing nurses activated significantly more complex inferences than the student groups. In each group, the majority of inferences were activated during the first half of the encounter. These results of this preliminary analysis support the proposition that inference activation is an important component of the diagnostic reasoning process used by both nurses and nursing students.

Cognition↗
PubMedDate not supplied

Systemic responses to different enteral feeding schedules in rats.

The purpose of this study was to describe selected temporal systemic responses to different enteral feeding schedules using an animal model, as one prerequisite for determining optimal delivery times for human enteral feedings. The effect of feeding schedules and time of day were examined relative to body weight and plasma glucose, insulin, glucagon, and corticosterone levels. Adult male Sprague-Dawley rats (N = 80) were used in a 4 x 4 randomized block design. Rats started the feeding schedules on Day 11 post-gastrostomy tube placement. The following feeding schedules, often used by humans, were tested: 24-hour enteral; 24-hour oral; 12-hour (rest time) enteral; and 12-hour (rest time) oral. Plasma was collected on Day 20. Despite very different feeding schedules, there were no statistical differences in weight gain, or plasma glucose and glucagon levels. Levels of insulin and corticosterone were significantly influenced by time of day and/or feeding group. Temporal pattern disruption was greatest in the rest-time fed enteral group. Both route and timing of enteral delivery modified metabolic hormone patterns.

Analysis of Variance↗
PubMedDate not supplied

Diagnostic reasoning strategies of nurses and nursing students.

This study described and compared the cognitive strategies of diagnostic reasoning used by junior nursing students (n = 15), senior nursing students (n = 13), and practicing nurses (n = 15). Verbal responses to three videotaped vignettes provided the data. Findings suggested that diagnostic reasoning processes of both nurses and nursing students can be described by a general model developed from studies of physicians. Subjects activated diagnostic hypotheses early in the encounter and used systematic information gathering to rule in and rule out hypotheses. With increased levels of knowledge and experience, there was a trend toward more systematic data acquisition and greater accuracy in diagnosis. The number of hypotheses activated, the earliness with which they were activated, and their diagnostic accuracy were task-specific components of the process, but selection of data-acquisition strategies appeared to be more generalizable across cases.

Cognition↗