Biomedical subjects

Richard Zeller

Publications and source records attributed to Richard Zeller.

7 recordsLinked to original sources

PubMed2007

In vitro pyrogen test--A new test method for solid medical devices.

Medical devices manufactured for implantation into humans must be free of any contamination with viable bacteria. However, remnants of dead bacteria and bacterial components alone may induce an inflammatory immune response. Pyrogen tests for such inflammatory contaminations are generally performed either by determining the content of lipopolysaccharide in rinsing solutions of batch samples by limulus amoebocyte lysate assay, by injecting the rinsing solutions into rabbits or by implanting batch samples into rabbits and measuring change of body temperature. In this study, we show that the in vitro pyrogen test (IPT), which measures the release of the inflammatory cytokine IL-1beta in fresh or cryopreserved human whole blood, can be used to assess the pyrogenic contamination of implantable medical devices. This test was used to check neurosurgical implants, namely aneurysm clips, as a proof of principle. Owing to the direct contact of the test material with the blood cells, this test does not require rinsing procedures, which have variable efficacy. The use of human blood ensures the detection of all substances that are pyrogenic for humans and reflects their relative potency. The safety of the products as delivered could be confirmed. The effects of sterilization and depyrogenization procedures on intentional pyrogenic contaminations of samples could be followed. This new application of the already internationally validated method promises to replace further rabbit pyrogen tests. It generates extremely sensitive results with an extended range of detectable pyrogenic contaminants.

Equipment and Supplies↗

PubMed2006

Self-esteem, parent-child interaction, emotional support, and self-perception among Thai undergraduate nursing students.

The purpose of this study was to examine the effect of parent-child interaction on self-esteem as mediated by emotional support and self-perception among undergraduate nursing students in Thailand. This study recruited 307 Thai baccalaureate nursing students who completed the Rosenberg Self-Esteem Scale, Ross Parent-Child Interaction Questionnaire, Emotional Support instrument, and Self-Perception questionnaire. Results revealed that the students reported relatively high self-esteem. A path model demonstrated the positive effect of parent-child interaction on emotional support and self-perception, and the positive effects of emotional support and self-perception on self-esteem. Self esteem was powerfully predicted from emotional support and moderately predicted from self-perception. These variables account for 37% of the variance in self esteem.

Adult↗

PubMed2006

Replication and extension of the Continuity and Discontinuity of Self Scale (CDSS).

PURPOSE: To replicate and extend development of an instrument to measure continuity and discontinuity of self after stroke. DESIGN: The conceptual basis for the instrument was derived from an existential phenomenologic study of stroke survivors, which showed that life after stroke included both continuity and discontinuity of self, experienced as control, independence, and connections with others. METHODS: A 45-item instrument with a three-point response set was designed with standard instrument techniques. Study instruments included the Barthel Index (measure of functional abilities), and a pre- and poststroke QoL Cantril Ladder. The sample size for the initial study was 55, and for the replication study was 50. Principal components analysis was used in both studies. Data analysis was done with both the sample of 50 and with the combined samples, N = 105. FINDINGS: The sample in the replication study had lower functional ability scores than did that of the original study; demographic characteristics were not significantly different. Factor analysis of the 50 cases robustly replicated the two-factor solution. When the samples were combined, however, a subtle pattern was detected in the "continuity" dimension, resulting in two factors for continuity and one factor for discontinuity, for an overall three-factor solution. CONCLUSIONS: Continuity appears two-dimensional, including control and independence as one dimension, and connections with others as the second. Discontinuity factored as a single dimension, indicating that perhaps loss permeates the components of discontinuity. Further study is in progress.

Adaptation, Psychological↗

PubMed2005

Depression, stress, emotional support, and self-esteem among baccalaureate nursing students in Thailand.

Nursing students are valuable human resources. Detection of potential depression among nursing students is crucial since depression can lead to low productivity, minimized quality of life, and suicidal ideas. Identifying factors affecting depression among students can help nursing educators to find ways to decrease depression. The purpose of this study was to examine rates of depression and the associations between depression and stress, emotional support, and self-esteem among baccalaureate nursing students in Thailand. This correlational, cross-sectional study recruited 331 baccalaureate Thai nursing students. Students completed three instruments that had been translated into Thai: The Center for Epidemiology Studies Depression Scale, Perceived Stress Questionnaire, and Rosenberg Self-Esteem Scale. Another instrument created in Thai was used to measure emotional support. Results revealed that, when using the standard definition, 50.1% of the students were depressed. Stress was positively related to depression, whereas emotional support and self-esteem were negatively related to depression.

Adult↗

PubMed2003

Longitudinal analysis of illness uncertainty, coping, hopefulness, and mood during participation in a clinical drug trial.

The purpose of this longitudinal study was to examine the relationships among illness uncertainty, coping effectiveness, hopefulness, and mood in persons with chronic, progressive multiple sclerosis (MS) during participation in a double-blind clinical drug trial. The similarities and differences in the pattern of relationships among variables were investigated within each of four data collection time frames and across time. The convenience sample comprised 52 participants with clinically definite MS who participated in a 2-year trial using methotrexate to treat progressive MS. Participants with more severe disability were found to be less hopeful and more emotionally distressed. Participants with higher levels of hopefulness used more effective coping strategies and had more positive moods, and those with greater uncertainty about their MS were likely to experience less hopefulness and more negative moods. The pattern of relationships among uncertainty, coping, hopefulness, and mood did not change throughout participation in the drug trial. The findings may be used as a foundation for planning nursing interventions with patients involved in drug studies.

Adaptation, Psychological↗

PubMed2003

Measuring continuity and discontinuity following stroke.

PURPOSE: To design and test a valid, reliable, and parsimonious instrument to measure continuity and discontinuity of self following stroke. DESIGN: A 45-item scale with a 3-point response set was developed. The conceptual basis, "continuity and discontinuity in the experience of self," was derived from an existential-phenomenological study of stroke survivors. Study instruments included the Barthel Index (measure of functional abilities) and the pre- and poststroke QoL Cantril Ladder. METHODS: The instruments were administered one time, in random order, to 55 stroke survivors in the United States in rehabilitation hospitals and in the community. Data were analyzed using a principal components factor analysis. RESULTS: A 2-factor solution with 10 items per factor was derived. Cronbach's alpha for Factor 1 (discontinuity of self) was .874 and for Factor 2 (continuity of self) was .869. Continuity and discontinuity were inversely related; continuity was related to functional abilities, but discontinuity was not. CONCLUSIONS: Use of this instrument validated findings from a qualitative study, which showed that life following stroke was a paradoxical sense of both continuity and discontinuity in the experience of self. This instrument can be used to measure the effectiveness of nursing interventions aimed at increasing stroke survivors' sense of continuity.

Activities of Daily Living↗

PubMedDate not supplied

The Ohio Midlife Women's Study.

The Ohio Midlife Women's Study was longitudinal with measurements occurring at three, 9-month intervals. Our purpose in doing this research was to examine predictors, moderators, and outcome variables associated with the transition to midlife in Caucasian and African American women. Predictor variables included loss and gain of resources. Moderators included menopause symptoms, menopausal status, attitude toward menopause, coping, and demographic characteristics. Outcome variables included anxiety, depression, and health promoting activities. To obtain the proposed final sample of 160 midlife women, an initial sample of 103 African American and 105 Caucasian "healthy" women were recruited in the community. Consistent predictors of anxiety were loss of resources, coping effectiveness, and education. Consistent predictors of depression were loss of resources and education. Health promoting activities were consistently predicted by attitude toward menopause and coping effectiveness. Stress is a better predictor of negative health outcomes than menopausal status.

Adaptation, Psychological↗