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Stress Study (stress + study)

Distribution by Scientific Domains

Medical Sciences	50%

Selected Abstracts

Adolescent stress and neural plasticity in hamsters: a vasopressin-serotonin model of inappropriate aggressive behaviour

EXPERIMENTAL PHYSIOLOGY, Issue 2000
Craig F. Ferris
Animal studies show that arginine vasopressin facilitates aggression, while serotonin (5-HT) inhibits aggression by blocking the activity of the vasopressin system. Clinical studies report that subjects with a history of ,fighting and assault' show a significant positive correlation between cerebrospinal fluid concentrations of vasopressin and aggression in the presence of a hyporeactive 5-HT system. Thus, in animals and humans, a hyporeactive 5-HT system may result in enhanced vasopressin activity and increased aggression. Can the stress of emotional and physical insult, i.e. threat and attack, during adolescence affect the development of the vasopressin and 5-HT systems and alter normal aggressive behaviour in early adulthood? Adolescent male golden hamsters were weaned at postnatal day 25, and stressed for 2 weeks by daily 1 h bouts of threat and attack by adult hamsters. Male littermates were run in a parallel stress study using daily 1 h trials of isolation in a novel environment. During early adulthood, on postnatal day 45, 3 days after the cessation of stress trials, animals were tested for aggression in a resident: intruder model. The results show a context-dependent change in aggression. Animals with a history of abuse show exaggerated attack behaviour toward smaller males compared to littermates with a history of isolation stress. Conversely, when confronted by males of equal size, animals with a history of abuse show diminished aggression and increased submission compared to controls. It was determined that the density of vasopressin fibres and neurones in the hypothalamus is lower in abused animals compared to controls. In contrast, the number of 5-HT terminals within the hypothalamus is higher in abused animals compared to controls. These results provide evidence in an animal model that stress in the form of threat and attack during adolescence can alter the balance between vasopressin and 5-HT in the brain, resulting in inappropriate aggressive behaviour in early adulthood. [source]

Self-esteem in community mental health nurses: findings from the all-Wales stress study

JOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 4 2000
A. Fothergill ph dbsc(hons)pgce rmn rgn
The authors conducted an all-Wales survey of community mental health nurses (CMHNs) to determine their levels of stress, coping and burnout. A total of 301 CMHNs were surveyed in 10 NHS Trusts in Wales. A range of measures were used. These included the General Health Questionnaire (GHQ-12), Maslach Burnout Inventory (MBI), Rosenberg Self-Esteem Scale (SES), Community Psychiatric Nursing (CPN) Stress Questionnaire, and PsychNurse Methods of Coping Questionnaire. The findings from the Rosenberg SES are reported here. Community mental health nurses in Wales scored as having average self-esteem. When the data were divided into high and low self-esteem, a large group of CMHNs (40%) were found to have low self-esteem. Factors that are associated with low and high self-esteem were identified. Alcohol consumption and being on lower nursing grades (D, E, F) were associated with low self-esteem, whilst amount of experience working as a CMHN was associated with high self-esteem. [source]

Uniaxial stress study of the Cu,H complex in ZnO

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 12 2006
E. V. Lavrov
The cover picture of the current issue refers to the article by Lavrov and Weber which was selected as Editor's Choice [1]. The picture shows a microscopic model of the Cu,H complex investigated in the paper. The complex consists of a substitutional Cu atom at the Zn site with an H atom located between nearby O and Cu in the basal plane of the ZnO lattice. The atoms are shown in different colors: yellow for copper, red for hydrogen, cyan for oxygen, and grey for zinc. Hydrogen forms a strong bond with the O atom which gives rise to a local vibrational mode at 3192 cm,1 investigated in the paper under uniaxial stress. The c -axis is parallel to the Cu,O bond pointing to the top of the figure. The authors work at the Institute of Applied Physics/Semiconductor Physics, TU Dresden, Germany. [source]

Comparison of 1- and 2-day protocols for myocardial SPECT: a Monte Carlo study

CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2005
H. H. El-Ali
Summary Background:, Myocardial perfusion single-photon emission computed tomography (SPECT) is carried out by combining a rest and a stress study that are performed either on one day or two separate days. A problem when performing the two studies on 1 day is that the residual activity from the first study contributes to the activity measured in the second study. Aim:, Our aim was to identify and evaluate trends in the quantification parameters of myocardial perfusion images as a function of separation time between rest and stress. Methods:, A digital phantom was used for the generation of heart images and a Monte Carlo-based scintillation camera program was used to simulate SPECT projection images. In our simulations, the rest images were normal and the stress images included lesions of different types and localization. Two programs for quantification of myocardial perfusion images were used to assess the different images in an automated and objective way. Results:, The summed difference scores observed with the 2-day protocol were 3 ± 1 (mean ± SD) higher for AutoQUANT and 2 ± 1 higher for 4D-MSPECT compared with those observed with the 1-day protocol. The extent values were 2% points higher for the 2-day protocol compared with the 1-day protocol for both programs. Conclusions:, There are differences in the quantitative assessment of perfusion defects depending on the type of protocol used. The contribution of residual activity is larger when a 1-day protocol is used compared with the 2-day protocol. The differences, although small, are of a magnitude that results in a clear shift in quantification parameters. [source]