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Search Results: 1 - 10 of 1003 matches for " Ulrike Ehlert "
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Effects of Psychosocial Stress on the Gene Expression of the Clock Genes hPER1 and hPER2 in Humans  [PDF]
Elvira A. Abbruzzese, Thomas Birchler, Ulrike Ehlert
Psychology (PSYCH) , 2014, DOI: 10.4236/psych.2014.51012

The circadian clock is a self-sustained time-keeping system which controls behavioral, biochemical and physiological rhythmic processes. In mammals, the cogwheels of this clock are the so-called clock genes which control their own expression via several feedback loops. One of these genes is hPER1, a clock gene which disposes of a glucocorticoid-responsive element and might therefore be influenced by glucocorticoids. In humans, stress is associated with an increase in the glucocorticoid cortisol and is seen as a major factor in the etiology of numerous mental health problems. For this reason, our goal was to investigate the putative cortisol-mediated influence of acute and chronic psychosocial stress on the gene expression of hPER1 as well as hPER2, another related clock gene from the same family. We therefore applied laboratory psychosocial stress to thirty-one healthy men and measured cortisol as well as mRNA levels of hPER1 and hPER2. Our main findings suggest that acute psychosocial stress influences the expression of hPER1 and hPER2 dependent on the subjective experience of chronic stress. We therefore conclude that the reactivity to acute stress on the gene expression level of these two genes differs significantly between subjects with high chronic stress compared to subjects with low chronic stress.

Psychobiological Effects of Prenatal Glucocorticoid Exposure in 10-Year-Old-Children
Roberto La Marca,Ulrike Ehlert
Frontiers in Psychiatry , 2012, DOI: 10.3389/fpsyt.2012.00104
Abstract: Background: Prenatal stress seems to have long-lasting effects on biological and psychological processes of the offspring. However, to date, there have been no studies investigating the effects of prenatal glucocorticoid exposure on psychological, endocrine, and autonomic responses to a standardized psychosocial stress test in children. Methods: A sample of 115 healthy, 10-year-old children was examined. The Glucocorticoids + Tocolytics group was characterized by tocolytic treatment of the mothers due to preterm labor (n = 43). In addition, the pregnant women received glucocorticoid treatment in order to accelerate fetal lung maturation in case of preterm birth. The first comparison group (Tocolytics) consisted of children whose mothers also experienced preterm labor, but did not receive glucocorticoid treatment (n = 35). In the second comparison group (CONTROL), children whose mothers had a complication-free pregnancy were assessed (n = 37). Psychological parameters (stress appraisal and mood) using self-report questionnaires as well as salivary cortisol, salivary alpha-amylase, and heart rate were measured during a standardized psychosocial stress test (Trier Social Stress Test for Children). Results: Group comparisons revealed that a subscale of stress appraisal, control expectancies, significantly differed in children who were prenatally exposed to glucocorticoids as compared to both comparison groups (F = 4.889, p = 0.009). Furthermore, significant differences between the groups were revealed for salivary cortisol. With respect to overall stress appraisal and heart rate, trends toward significance were observed between the three groups. Conclusion: At the age of ten, those children who have been exposed to prenatal maternal glucocorticoids show changed psychobiological stress reactivity to a standardized psychosocial stress test as compared to control children.
Rebecca Br?nnimann,Jane Herlihy,Julia Müller,Ulrike Ehlert
European Journal of Psychology Applied to Legal Context , 2013,
Abstract: While differences in witness narratives due to different interviewers may have implications for their credibility in court, this study considers how investigative interviews by different parties to the proceedings, as well as the gender and nationality of interviewers, can influence the testimony of witnesses in court who share comparable traumatic experiences. The foundation of the analysis was answers given to judges, prosecutors, civil party lawyers and defence lawyers in the Extraordinary Chambers in the Courts of Cambodia (ECCC) located in Phnom Penh. Transcribed testimonies of 24 victim witnesses and civil parties which were translated from Khmer into English were analysed using a computer-based text analysis program, the Linguistic Inquiry and Word Count (LIWC). Results showed that when answering questions by females, witnesses used significantly more cognitive process words. When interviewed by international rather than by Cambodian parties to the proceeding witness accounts were composed of significantly more verbal expressions of affective processes and of perceptual processes. Furthermore, witnesses used most cognitive and affective process words during the interview by civil party lawyers and defence lawyers. These results may be due to a prior supportive relationship between civil parties and their lawyers and due to a more interrogative question style by the defence lawyers, who attempt to undermine the credibility of the interviewed witnesses. Data shows that LIWC analysis is an appropriate method to examine witness accounts and, therefore, contributes to a better understanding of the complex relationship between testimony in events under litigation and credibility.
Acute Stress Reduces Wound-Induced Activation of Microbicidal Potential of Ex Vivo Isolated Human Monocyte-Derived Macrophages
Ulrike Kuebler, Petra H. Wirtz, Miho Sakai, Andreas Stemmer, Ulrike Ehlert
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0055875
Abstract: Background Psychological stress delays wound healing but the precise underlying mechanisms are unclear. Macrophages play an important role in wound healing, in particular by killing microbes. We hypothesized that (a) acute psychological stress reduces wound-induced activation of microbicidal potential of human monocyte-derived macrophages (HMDM), and (b) that these reductions are modulated by stress hormone release. Methods Fourty-one healthy men (mean age 35±13 years) were randomly assigned to either a stress or stress-control group. While the stress group underwent a standardized short-term psychological stress task after catheter-induced wound infliction, stress-controls did not. Catheter insertion was controlled. Assessing the microbicidal potential, we investigated PMA-activated superoxide anion production by HMDM immediately before and 1, 10 and 60 min after stress/rest. Moreover, plasma norepinephrine and epinephrine and salivary cortisol were repeatedly measured. In subsequent in vitro studies, whole blood was incubated with norepinephrine in the presence or absence of phentolamine (norepinephrine blocker) before assessing HMDM microbicidal potential. Results Compared with stress-controls, HMDM of the stressed subjects displayed decreased superoxide anion-responses after stress (p’s <.05). Higher plasma norepinephrine levels statistically mediated lower amounts of superoxide anion-responses (indirect effect 95% CI: 4.14–44.72). Norepinephrine-treated HMDM showed reduced superoxide anion-production (p<.001). This effect was blocked by prior incubation with phentolamine. Conclusions Our results suggest that acute psychological stress reduces wound-induced activation of microbicidal potential of HMDM and that this reduction is mediated by norepinephrine. This might have implications for stress-induced impairment in wound healing.
Mental health of asylum seekers: a cross-sectional study of psychiatric disorders
Martina Heeren, Julia Mueller, Ulrike Ehlert, Ulrich Schnyder, Nadia Copiery, Thomas Maier
BMC Psychiatry , 2012, DOI: 10.1186/1471-244x-12-114
Abstract: The mental health status of two groups of asylum seekers was assessed: Group 1 (n?=?43) had arrived in Switzerland 2.9 (SD 1.1) months prior to assessment, while Group 2 (n?=?43) had arrived 15.5 (SD 3.2) months prior to assessment. Psychiatric disorders were diagnosed using the Mini International Neuropsychiatric Interview (MINI). Symptom severity of posttraumatic stress disorder (Posttraumatic Diagnostic Scale), anxiety (Hopkins Symptom Checklist), depression (Hopkins Symptom Checklist), and pain (Verbal Rating Scale) were assessed using self-report questionnaires. Postmigratory factors such as German language proficiency and social contacts were also assessed. Interviews were conducted with the assistance of trained interpreters.Four out of ten participants met diagnostic criteria for at least one DSM-IV disorder. Groups did not differ with respect to psychiatric morbidity or symptom levels. Major depression (31.4%) and PTSD (23.3%) were diagnosed most frequently. The number of experienced traumatic event types was highly correlated with psychiatric morbidity.Psychiatric morbidity in asylum seekers in the first two years after arrival is high, with no indication of a decrease in mental distress over time. Traumatic experiences seem to play a major role in morbidity during this time. Considering the magnitude of clinically relevant distress, a short psychological screening upon arrival with a focus on traumatic experiences may be warranted.Heightened international research in the area of refugee mental health has highlighted the particular vulnerability of asylum seekers. Distress and psychiatric morbidity are known to be high in this population, with posttraumatic stress disorder (PTSD) rates ranging from 20% to 40% and anxiety and depression rates from 30% to 70% having been reported [1-3].In most countries, asylum seekers are not screened for mental health problems at any point during the asylum procedure. Consequently, it is not surprising that recent findings
The Effect of Music on the Human Stress Response
Myriam V. Thoma, Roberto La Marca, Rebecca Br?nnimann, Linda Finkel, Ulrike Ehlert, Urs M. Nater
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0070156
Abstract: Background Music listening has been suggested to beneficially impact health via stress-reducing effects. However, the existing literature presents itself with a limited number of investigations and with discrepancies in reported findings that may result from methodological shortcomings (e.g. small sample size, no valid stressor). It was the aim of the current study to address this gap in knowledge and overcome previous shortcomings by thoroughly examining music effects across endocrine, autonomic, cognitive, and emotional domains of the human stress response. Methods Sixty healthy female volunteers (mean age = 25 years) were exposed to a standardized psychosocial stress test after having been randomly assigned to one of three different conditions prior to the stress test: 1) relaxing music (‘Miserere’, Allegri) (RM), 2) sound of rippling water (SW), and 3) rest without acoustic stimulation (R). Salivary cortisol and salivary alpha-amylase (sAA), heart rate (HR), respiratory sinus arrhythmia (RSA), subjective stress perception and anxiety were repeatedly assessed in all subjects. We hypothesized that listening to RM prior to the stress test, compared to SW or R would result in a decreased stress response across all measured parameters. Results The three conditions significantly differed regarding cortisol response (p = 0.025) to the stressor, with highest concentrations in the RM and lowest in the SW condition. After the stressor, sAA (p=0.026) baseline values were reached considerably faster in the RM group than in the R group. HR and psychological measures did not significantly differ between groups. Conclusion Our findings indicate that music listening impacted the psychobiological stress system. Listening to music prior to a standardized stressor predominantly affected the autonomic nervous system (in terms of a faster recovery), and to a lesser degree the endocrine and psychological stress response. These findings may help better understanding the beneficial effects of music on the human body.
Different approaches of high speed data transmission standards
M. Ehlert
Advances in Radio Science : Kleinheubacher Berichte , 2004,
Abstract: A number of standards addresses the problem of high-speed data transmission on serial or serial-parallel data lines. Serial-parallel data transmission means the transmitted information is distributed on parallel data lines. Even though several standards exist, there are only a few basic techniques used in most of these standards. This paper is giving an overview of these different basic techniques used in the physical layer of today’s data transmission standards, for example DVI/HDMI, USB2.0, Infiniband, SFI5, etc. [1–9]. The main focus lies on the approaches used for physical signaling, line coding and information synchronization in serial and serialparallel systems. In addition, currently discussed techniques to improve data transmission in the future will be presented.
Diagnosis of Rabies via RT-PCR on Skin Samples of Wild and Domestic Animals  [PDF]
Ulrike Zieger
Open Journal of Veterinary Medicine (OJVM) , 2015, DOI: 10.4236/ojvm.2015.59026
Abstract: In developing countries, brain tissues from rabies suspect animals are not always available for diagnosis for a variety of reasons, such as lack of transport to submit a carcass or the difficulty of removing an animal’s head or brain under field conditions. To enable diagnosis in such cases, there is a need for a reliable method, using an alternative non-neural tissue, which can be removed and submitted to the diagnostic laboratory without special training or equipment. In human medicine, skin is used successfully for the detection of rabies virus antigen using RT-PCR technology. Little work has been done in animals using RT-PCR on skin or extracted hair follicles. The current study was conducted in Grenada on skin from 36 wild and domestic animals, in which rabies virus infection had been confirmed in brain tissue via the direct fluorescent antibody (DFA) test, and in 31 negative control animals. RT-PCR on skin yielded a sensitivity of 97.2% (35/36) and a specificity of 100% (31/31). It is concluded that the examination of skin samples via RT-PCR provides a valuable diagnostic alternative in those cases where brain tissue is not readily available.
Idéias em movimento: a gera o 1870 na crise do Brasil Império
Jo?o Ehlert Maia
Tempo Social , 2004, DOI: 10.1590/s0103-20702004000100016
Lazy Updating increases the speed of stochastic simulations
Kurt Ehlert,Laurence Loewe
Quantitative Biology , 2013,
Abstract: Biological reaction networks often contain what might be called 'hub molecules', which are involved in many reactions. For example, ATP is commonly consumed and produced. When reaction networks contain molecules like ATP, they are difficult to efficiently simulate, because every time such a molecule is consumed or produced, the propensities of numerous reactions need to be updated. In order to increase the speed of simulations, we developed 'Lazy Updating', which postpones some propensity updates until some aspect of the state of the system changes by more than a defined threshold. Lazy Updating works with several existing stochastic simulation algorithms, including Gillespie's direct method and the Next Reaction Method. We tested Lazy Updating on two example models, and for the larger model it increased the speed of simulations over eight-fold while maintaining a high level of accuracy. These increases in speed will be larger for models with more widely connected hub molecules. Thus Lazy Updating can contribute towards making models with a limited computing time budget more realistic by including previously neglected hub molecules.
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