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Biomedical subjects

M Topf

Publications and source records attributed to M Topf.

At least 19 recordsLinked to original sources
PubMed2001

Modeling the 3D structure of GPCRs from sequence.

G-protein-coupled receptors (GPCRs) are a large and functionally diverse protein superfamily, which form a seven transmembrane (TM) helices bundle with alternating extra-cellular and intracellular loops. GPCRs are considered to be one of the most important groups of drug targets because they are involved in a broad range of body functions and processes and are related to major diseases. In this paper we present a new technology, named PREDICT, for modeling the 3D structure of any GPCR from its amino acid sequence. This approach takes into account both internal protein properties (i.e., the amino acid sequence) and the properties of the membrane environment. Unlike competing approaches, the new technology does not rely on the single known structure of rhodopsin, and is thus capable of predicting novel GPCR conformations. We demonstrate the capabilities of PREDICT in reproducing the known experimental structure of rhodopsin. In principle, PREDICT-generated models offer new opportunities for structure-based drug discovery towards GPCR targets.

Amino Acid Sequence↗
PubMed2000

Hospital noise pollution: an environmental stress model to guide research and clinical interventions.

Hospital noise pollution: an environmental stress model to guide research and clinical interventions This commentary provides an expanded environmental stress model. Conceptual relationships between ambient stressors, ambient stress, and health are detailed. A three-part intervention, enhancement of person-environment compatibility, is specified. Details are provided on how this approach to reducing environmental pollution/hazards and sustaining these changes may be influenced by sociopolitical values, technological advances, and motivation for control over hazards. Personal variables thought to mediate the impact of environmental stress on health, including intrinsic sensitivity to specific hazards, personality, restricted capacities, other stress, culture, personal preferences, stage of life, gender, and perceived social support, are highlighted. Research results on the stress and health effects of hospital noise on patients and nurses are summarized to provide support for the model. Future directions for research are recommended. Implications of the model for nursing, including an environmental activist role in an interdisciplinary effort to plan and implement noise abatement interventions, are described.

Attitude of Health Personnel↗
PubMed1996

Effects of critical care unit noise on the subjective quality of sleep.

Nurse researchers have provided evidence that hospital critical care unit (CCU) noise may put patients at risk for sleep problems. Technological advances in this setting have been described as contributing to this problem. Although data on the negative effects of CCU noise on physiological sleep are available, less attention has been given to self-reports of the subjective quality of sleep following exposure to this stressor. This study hypothesized that subjects exposed to CCU sound levels would report poorer subjective sleep than subjects in a quieter environment. Sixty female subjects, attempting to sleep overnight in a laboratory, were randomly assigned to an experimental group, where they heard an audiotape recording of CCU sounds throughout the night, or to a quiet group where the audiotape recording of CCU sounds was withheld. A self-rating questionnaire was used to assess subjective sleep. The noise condition subjects reported taking longer to fall asleep, less time sleeping, more awakenings, poorer quality of sleep compared to home, as well as fewer positive and more negative adjectives descriptive of sleep. Self-reports of the time spent sleeping and the number of negative adjectives descriptive of sleep yielded the greatest number of significant correlations with scores for the other measures of sleep, indicating that these measures may be more accurate. Data on the quality of dreams yielded no difference between groups. The results provide support for the hypothesis that CCU sound levels impact negatively on subjective sleep. It was recommended, now that CCU sound levels were isolated in the laboratory as a potential stressor, that future research should attempt to replicate this study in a hospital CCU.

Adult↗
PubMed1994

Personality hardiness, work-related stress, and health in hospital nurses.

Personality hardiness is a set of beliefs about oneself and the world one lives in. Hardier persons take control of their lives, believe that commitment to goals will result in positive outcomes, and perceive daily stressors as challenges. Hardiness has been linked with less stress and fewer health problems among various occupational groups. This study found that among 237 hospital nurses, work-related stress and emotional exhaustion were associated with greater health problems in the form of anxiety, depression, and somatic complaints. Hardier nurses reported less work-related stress, less emotional exhaustion, and less anxiety, depression, and somatization. This article discusses considerations for strengthening future studies concerned with the relationships between personality hardiness, work-related stress, and health in nurses.

Burnout, Professional↗
PubMed1994

Theoretical considerations for research on environmental stress and health.

Research on hospital noise may have implications for the usefulness of stress theory as a framework for the study of environmental stress and stress-related health outcomes. In this article, the results of hospital noise research are described. It is argued that noise-induced stress in hospitals is largely uncontrollable by individual coping and that stress theory may therefore need to be supplemented for the reduction of reactivity. Three concepts are proposed for this purpose. Primary among these is an intervention concept--enhancement of person-environment compatibility. Others are ongoing societal and technological development, and intrinsic sensitivity to specific stressors in the environment. Future research should attempt to reveal whether these concepts are consistently effective in the management of hospital noise and other environmental stressors.

Adaptation, Psychological↗
PubMed1992

Effects of personal control over hospital noise on sleep.

Critical Care Unit (CCU) sound levels, subjective stress due to noise, and sleep were studied in 105 female volunteers in a simulated hospital environment. Subjects were randomly assigned to instruction in personal control over noise via the availability of a sound conditioner, no instruction in personal control over noise, or quiet conditions. Subjects in the two noise conditions heard audiotape-recorded CCU nighttime sounds while attempting to sleep overnight in the laboratory. The intervention did not facilitate better sleep as measured by polysomnograph equipment and self-report. However, the results provided strong support for a causal relationship between CCU sounds and poorer sleep. When compared to the quiet condition, subjects in the noise conditions had poorer sleep efficiency; more difficulty falling and staying asleep; more difficulty progressing from one stage of sleep to the next; more intrasleep awakenings; spent less time in Rapid Eye Movement sleep; and poorer sleep via self-report (all ps less than .03). As predicted, scores for subjective stress due to CCU sounds yielded significant relationships with 9 of 16 measures of sleep (all ps less than .01). Hierarchical multiple regressions showed that 13% (p less than .001) and close to 6% (p less than .05) of the variance in sleep efficiency was accounted for by CCU sound levels and noise-induced subjective stress, respectively. Thirty-eight percent (p less than .001) of the variance in Rapid Eye Movement sleep was accounted for by CCU sound levels.

Adult↗
PubMed1992

Stress effects of personal control over hospital noise.

Hospital critical care unit (CCU) sounds, instruction in personal control over noise, and stress were studied in 105 female volunteers attempting to sleep overnight in a simulated hospital environment. Subjects were randomly assigned to three groups--instruction in personal control over noise, no instruction in personal control over noise, or a quiet condition. The two noise conditions heard audiotaped recorded playback of CCU nighttime sounds. The subjects with instruction in personal control received directions for using a sound conditioner to block out unwanted sounds. This intervention failed to result in less stress. The results of group comparisons provided strong support for a causal relationship between CCU sounds and greater subjective stress (p less than .000) but not for physiological stress measured by urinary epinephrine. As predicted, scores for sensitivity of the person to noise were positively correlated with scores for noise-induced subjective stress (r = .226, p less than .05). Hierarchical multiple regression revealed that CCU sound levels independently accounted for 54% (p less than .001) and sensitivity to noise for 5% (p less than .01) of the variance in subjective stress.

Adaptation, Psychological↗
PubMed1990

Increasing the validity of research results with a blend of laboratory and clinical strategies.

Some nursing research problems may benefit from studies that combine laboratory and clinical research settings. Examples of studies that use a blend of laboratory and clinical components are provided. Traditional laboratory, clinical, and combined laboratory-clinical research settings are discussed in terms of their relative potential for yielding valid results.

Clinical Nursing Research↗
PubMed1989

Personality hardiness, occupational stress, and burnout in critical care nurses.

Personality hardiness, occupational stress, and burnout were investigated in 100 critical care nurses. Hardiness was predictive of occupational stress and burnout. Hierarchical multiple regressions revealed that one of the three dimensions of hardiness, commitment to work, was the only variable to account for significant amounts of variance (up to 24%) across three of four measures of burnout. The study did not provide support for the stress buffering effect of hardiness. That is, an interaction term, hardiness x occupational stress, was not convincingly predictive of burnout in nurses. The findings are discussed in terms of other research on burnout in critical care nurses and recent issues on the conceptualization of hardiness.

Adult↗
PubMed1988

Noise-induced stress as a predictor of burnout in critical care nurses.

In this study we found that, for 100 critical care nurses, noise-induced occupational stress was positively related to burnout as measured by Jones's Staff Burnout Scale for Health Professionals (r = 0.369, p less than 0.001) and the emotional exhaustion subscale of Maslach's Burnout Inventory (r = 0.300, p less than 0.01). Hierarchical multiple regressions confirmed these results once variance in burnout linked with life stressors and other occupational stressors was accounted for. Furthermore, an interaction term, noise-induced stress X intrinsic sensitivity to noise in the person, did not account for significant variance in burnout once independent variance linked with noise-induced stress was identified. That is, nurses with intrinsic sensitivity to noise were no more at risk for burnout linked with noise-induced stress than were less sensitive nurses. This result is discussed as evidence that there are exceptionally high levels of noise in critical care units. The critical care unit noises that are most distressing to nurses are identified and discussed in terms of stress theory.

Adult↗
PubMed1985

Noise-induced stress in hospital patients: coping and nonauditory health outcomes.

This study found that, for 150 postoperative male patients, degree of objective noise, intrinsic sensitivity of the person to noise, and noise-induced stress were positively related to coping, in the form of exercised control over noise (correlations ranged from r = .207 to r = .468, P less than .01 for all cases). Hierarchical multiple regression confirmed these results. Furthermore, greater sensitivity of the person to noise was positively correlated with ability to cope, regardless of the objective level of noise. Patients who were randomly assigned to an experimental group, where they received instructions for control over noise, showed no difference in coping ability than a control group. There was a lack of support for several hypotheses concerned with the effects of noise-induced stress and coping on health, where stress was measured by self-reports of recovery and average time-out-of-bed in minutes. The meaning of these results is discussed in terms of stress theory.

Adaptation, Psychological↗
PubMed1984

A framework for research on aversive physical aspects of the environment.

A theoretical framework for organizing research on the health effects from aversive physical aspects of the environment is specified. The nurse's role in preparing individuals to control aversive environmental stimuli and the effects of this on reactivity and health are detailed. The framework is substantiated by using the impact of hospital noise upon recovery as an example. Supportive theoretical and research literature are presented for the relationships hypothesized in the framework.

Adolescent↗
PubMed1981

Teaching interpersonal skills: a model for facilitating optimal interpersonal relations.

This article draws upon the results of a series of studies involving observations of interviews involving psychiatric patients and their friends, and between psychiatric patients and nurses. A two-dimensional structure of interpersonal behavior is described. Three principles of effective interpersonal relations are detailed, including interpersonal complementarity, interpersonal versatility, and interpersonal influence. Research results that indicate how psychiatric patients have trouble exercising these principles are reported. A three-phased assessment, intervention, and reassessment approach to facilitating interpersonal skills in patients is detailed. A counselor-teacher approach to the treatment of psychiatric patients is recommended.

Humans↗