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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The relationship between cortisol, c-reactive protein and hypertension in the development of cardiovascular dysfunction in African and Caucasian women : the POWIRS study / Claire Tolmay

Tolmay, Claire January 2009 (has links)
Motivation: C-reactive protein (hs-CRP) and other risk factors such as cortisol and obesity in the diagnosis of cardiovascular dysfunction (CVD) in African and Caucasian women has become increasingly imperative when one considers the escalation of hypertension among these groups. Recent studies have explored some aspects of these risk factors and the roles that they play within hypertension and possible future risk for cardiovascular disease. Hs-CRP has been associated with the increased prevalence of hypertension and obesity. Cortisol per se has also been linked with the development of both hypertension and the hypothalamic-pituitary adrenal cortex (HPA) response. Nevertheless, the exact mechanism remains rather uncertain due to conflicting outcomes of research within different ethnic groups. Several recent investigations have, however, linked hypocortisolism with both urbanisation and a subsequent increased likelihood of hypertension within African women as they have presented increased vascular blood pressure responses. Conversely, Caucasian women have displayed an increased central cardiac reactivity. The lack of data regarding the relationship between the above-mentioned parameters within both African and Caucasian women serves as the motivation for conducting this study. Objective: To investigate hs-CRP, cortisol and hypertension as contributors to the increased likelihood of cardiovascular dysfunction in both African and Caucasian women within South Africa. hs-CRP use this through whole document please Methodology: The manuscript presented in Chapter 2 has been compiled using data obtained from the POWIRS (Profiles of Obese Women with Insulin Resistance Syndrome) study. Apparently healthy African (N=102) and Caucasian (N=115) women, matched for age and body mass index, were recruited from the North-West Province of South Africa for participation within this study. Subjects were divided into normotensive (NT) and hypertensive (HT) groups according to the mean resting cardiovascular values that were taken using a Finometer device. High-sensitivity C-reactive protein (hs-CRP) and cortisol blood serum values were determined by immunochemistry and ELISA analyses. Significant differences within each ethnic group and between each of the groups (NT and HT) were determined by analysis of covariance (ANCOVA), for anthropometric, cardiovascular, hs-CRP and cortisol variables, while adjusting for cardiovascular covariates (age, smoking and alcohol consumption). Partial correlations analyses were used to examine the relationship between hs-CRP, cortisol, anthropometric and cardiovascular parameters adjusting for cardiovascular covariates. Logistic regression analyses was used within each ethnic group to determine the relationship between anthropometric, cardiovascular, hs-CRP and cortisol as independent variables and hypertension as dependent variable. This study was approved by the Ethics Committee of the North-West University and all subjects gave informed consent in writing. For a more detailed description of the subjects, study design and analytical procedures please refer to the Materials and Methods section within Chapter 2 of this dissertation. Results and Conclusion: Both ethnic groups presented higher hs-CRP and lower cortisol levels compared to normal values. Lower waist circumference (WC) and cortisol as well as higher blood pressure (BP) and vascular values were evident in Africans compared to Caucasians. Both HT ethnic groups were older and more visceral obese compared to their NT counterparts. HT Caucasians indicated higher central adrenergic responses whilst HT Africans showed vascular adrenergicresponses. Only NT Africans had lower cortisol values than NT Caucasians but the Africans (NT and HT) responded with higher diastolic blood pressure responses compared to their Caucasian counterparts. Moreover, hs-CRP within African women significantly correlated with all BP and obesity variables whilst hs-CRP only associated with stroke volume (SV) and compliance (Cw) within HT Caucasian women. Cortisol in both ethnic groups was strongly associated with vascular BP responses. Only BP contributed to the higher prevalence of HT in both ethnic groups. In conclusion, these results suggest the possible diverse roles of HPA axis dysregulation associated with higher inflammatory responses. This happens in conjunction with cardiac and vascular responses within more obese Caucasian and especially African women, respectively. / MSc (Physiology), North-West University, Potchefstroom Campus, 2009
12

The scanner as a stressor: Evidence from subjective and neuroendocrine stress parameters in the time course of a functional magnetic resonance imaging session

Mühlhan, Markus, Lüken, Ulrike, Wittchen, Hans-Ulrich, Kirschbaum, Clemens 13 August 2013 (has links) (PDF)
Subjects participating in magnetic resonance imaging (MRI) examinations regularly report anxiety and stress related reactions. This may result in impaired data quality and premature termination of scans. Moreover, cognitive functions and neural substrates can be altered by stress. While prior studies investigated pre–post scan differences in stress reactions only, the present study provides an in-depth analysis of mood changes and hormonal fluctuations during the time course of a typical fMRI session. Thirty-nine subjects participated in the study. Subjective mood, salivary alpha-amylase (sAA) and cortisol were assessed at six time points during the lab visit. Associations between hormonal data and neural correlates of a visual detection task were observed using a region of interest approach applied to the thalamic region. Mood and hormonal levels changed significantly during the experiment. Subjects were most nervous immediately after entering the scanner. SAA was significantly elevated after MRI preparation. A subgroup of n = 5 (12.8%) subjects showed pronounced cortisol responses exceeding 2.5 nmol/l. Preliminary fMRI data revealed an association between sAA levels and left thalamic activity during the first half of the experiment that disappeared during the second half. No significant correlation between cortisol and thalamic activity was observed. Results indicate that an fMRI experiment may elicit subjective and neuroendocrine stress reactions that can influence functional activation patterns.
13

Within and between session changes in subjective and neuroendocrine stress parameters during magnetic resonance imaging: A controlled scanner training study

Lüken, Ulrike, Mühlhan, Markus, Evens, Ricarda, Wittchen, Hans-Ulrich, Kirschbaum, Clemens 15 August 2013 (has links) (PDF)
Accumulating evidence suggests that the magnetic resonance imaging (MRI) scanner can act as a stressor, eliciting subjective and neuroendocrine stress responses. Approaches to familiarize subjects with the scanner could help minimizing unintended effects on neural activation patterns of interest. Controlled studies on the effects of a scanner training are however missing. Using a comparative design, we analyzed within- and between session changes in subjective and neuroendocrine stress parameters in 63 healthy, scanner-naïve adults who participated in a two-day training protocol in an MRI, mock, or lab environment. A habituation task was used to assess within-session changes in subjective and neuroendocrine (cortisol) stress parameters; between-session changes were indicated by differences between days. MRI and mock, but not lab training were successful in reducing subjective distress towards the scanner. In contrast, cortisol reactivity towards the training environment generally increased during day 2, and the percentage of cortisol responders particularly rose in the mock and MRI groups. Within-session habituation of subjective arousal and anxiety was observed during both days and irrespective of training condition. Present findings demonstrate that training in a scanner environment successfully reduces subjective distress, but may also induce sensitization of endocrine stress levels during repeated scanning. Subjective distress can further be stabilized by acclimating subjects to the environment prior to the MRI assessment, including a short habituation phase into the assessment protocol. If replicated, present findings should be considered by researchers employing repeated measurement designs where subjects are exposed to a scanner more than once.
14

Störungsspezifische, visuelle emotionale Stimuli bei der Agoraphobie mit Panikstörung / Disorder specific emotional imagery for differential and quantitative assessment of agoraphobia

Neumann, Marie-Charlott 10 October 2012 (has links)
No description available.
15

Evaluation einer aktuellen Handlungsempfehlung zur Narkoseeinleitung des nicht nüchternen Säuglings mithilfe eines neu entwickelten simulatorbasierten Modells / Evaluation of a new practice guideline for the induction of general anaesthesia of non-fasted infants using a novel simulation-based model

Nickut, Andrea 13 May 2015 (has links)
Die vorliegende Arbeit befasst sich mit der Evaluierung einer neuen klinischen Handlungsempfehlung zur Rapid Sequence Induction (RSI) des nichtnüchternen Säuglings sowie eines neuen Modells zur simulatorbasierten Evaluation akutmedizinischer, klinischer Leitlinien.  Bei der klassischen RSI kommt es aufgrund der fehlenden Zwischenbeatmung während der Narkoseeinleitung zu hohem Zeitdruck. Sie ist technikbedingt assoziiert mit Hypoxämie beim Patienten und einem hohen Stresslevel beim Anwender (Eich et al. 2009a). Stress wiederum ist ein potentieller Trigger bei der Entstehung unsicherer Handlungen und kritischer Ereignisse. Aus diesem Grund gab der wissenschaftliche Arbeitskreis Kinderanästhesie der Deutschen Gesellschaft für Anästhesiologie und Intensivmedizin (DGAI) im Jahre 2007 eine neue Handlungsempfehlung zur Narkoseeinleitung des nichtnüchternen Säuglings (kontrollierte RSI) heraus (Schmidt et al. 2007; Schreiber 2007).  Wesentliche Änderungen sind die geplante Durchführung einer sanften Zwischenbeatmung via Maske, der Verzicht auf Succinylcholin als Muskelrelaxans und das Weglassen des Krikoiddrucks. Dadurch sollten Zeitdruck und Stress vermindert sowie die Inzidenz der damit zusammenhängenden unsicheren Handlungen und kritischen Ereignisse reduziert werden. Für unsere Studie entwickelten wir ein simulatorbasiertes Modell, um die kontrollierte (neue) RSI-Technik mit der klassischen (bisherigen) RSI-Technik vergleichend zu evaluieren. Dabei kombinierten wir Methoden der Observation, der Stressmessung und der der Selbsteinschätzung. An der kontrollierten, randomisierten Studie nahmen 30 männliche Anästhesisten (Fachärzte und Weiterbildungsassistenten) teil. Sie absolvierten am Säuglingssimulator (SimBaby®) eine standardisierte Narkoseeinleitung bei einem vier Wochen alten Säugling mit obstruktiver Pylorusstenose. Jeweils 15 Probanden absolvierten die klassische und die kontrollierte RSI (Eich et al 2009a; Eich et al. 2009b). Das Szenario mit den Vitalzeichen und deren Trends wurden zuvor programmiert. Während des Versuchs beobachteten wir unsichere Handlungen und kritische Ereignisse wie Hypoxämie (SpO2 < 90%), forcierte Maskenbeatmung, Intubationsschwierigkeiten und -Komplikationen. Zusätzlich maßen wir den Stress der Probanden mithilfe der Ergospirometrie (Herz-, Atemfrequenz und Atemminutenvolumen sowie O2-Verbrauch und CO2-Produktion), der Analyse von Kortisol und α-Amylase im Speichel und eines Selbsteinschätzungsfragebogens (subjektives Stress- und Sicherheitsempfinden)  (Eich et al. 2009a; Eich et al. 2009b). Bei allen Probanden konnte im Verlauf des Szenarios ein deutlicher, reproduzierbarer Anstieg aller Stressparameter gemessen werden. Bei der kontrollierten RSI waren objektiv gemessene Stressparameter sowie das subjektive Stressempfinden niedriger als bei der klassischen RSI. Bei der klassischen RSI entwickelte sich, im Gegensatz zur kontrollierten RSI, immer eine Hypoxämie. Die Inzidenz der übrigen unsicheren Handlungen und kritischen Ereignisse war bei beiden Methoden relativ gering.  Unsere Daten zeigen, dass die kontrollierte RSI - im Vergleich zur klassischen RSI - den Stress bei den Anwendern und damit das Entstehen unsicherer Handlungen und kritischer Ereignisse zu reduzieren vermag (Eich et al 2009a). Das neuentwickelte simulatorbasierte Modell hat sich dabei als praktikabel und valide erweisen zur Evaluation akutmedizinischer, klinischer Leitlinien (Eich et al 2009b).
16

Skogsbad och stresslindring : En litteraturstudie om skogsbad och kortisolkoncentration för minskad stress

Gyllenbris, Marylin January 2020 (has links)
Bakgrund: Andelen människor som känner sig stressade ökar. Långa perioder med stress och därigenom höga kortisolnivåer kan leda till skador, sjukdomar och utmattning. Samtidigt blir avslappningsformer så som skogsbad allt vanligare. Skogsbad kommer från Japan och bygger på biofilihypotesen, att människan har ett behov av att känna tillhörighet med naturen. Den här studien fokuserar på att minska negativ stress. Syfte: Undersöka huruvida det finns vetenskapliga belägg att skogsbad sänker kortisolkoncentrationen. Hypotesen är att skogsbad har effekt på kortisolhalterna och därför minskar stress. Metod: Systematisk litteraturstudie med sökning i databaserna pubMed, Google Scholar och Onesearch. Nio artiklar mötte inkluderingskriterierna och togs med i studien. Resultat: Studien ger stöd åt hypotesen och sex av de totalt nio inkluderade studierna visar på signifikant positiva effekter på kortisolkoncentrationerna. Slutsats: Skogsbad ser ut att ha positiva effekter på stress. / Background: The number of people who suffer from negative stress is increasing. Long periods with high cortisol levels may cause damage, illness and fatigue. Relaxation activities, such as forest bathing, has become popular during the last few years. Forest bathing originates in Japan and relay on the biofilia hypothesis which suggests that humans has an urge to belong to nature. This study focus on negative stress. Aim: To study if there are scientific evidence supporting the hypothesis that forest bathing may decrease cortisol concentrations. Methods: a systematic review using the databases pubMed, Google scholar and Onesearch. In total, nine articles met the inclusion criteria and were included in the study. Results: This study lends support for the hypothesis and six out of the totally nine studies included showed significant positive effect on cortisol concentrations. Conclusion: Forest bathing appear to have positive effects on stress.
17

Adult Children of Divorce : Stress and Well-Being

Olofsson, Emmie January 2020 (has links)
Parental divorce has not only been associated with negative long-term effects for children of divorce (CD), but also for adult children of divorce (ACD). ACD more often have poorer mental well-being than adult children of marriage (ACM). Neurological research further suggests that ACD have lower baseline levels of the “stress hormone” cortisol. However, research of Swedish ACD is extremely sparsely. Therefore, the study’s aim is to examine the possible long-term effects of Swedish ACD. Do ACD have lower well-being and experience more stress than ACM? A sample of 227 Swedish participants (81 ACD and 146 ACM) were included. The majority (75.7%) were between 18-30 years old, 157 females and 70 males. An online survey including the Perceived Stress Scale (PSS), the Temporal Satisfaction with Life Scale (TSWLS), and questions about the parental divorce was distributed via social media. Independent t-tests and one-way ANOVA analysis were performed to compare ACD’s and ACM’s results. The study found that ACD rated their well-being (satisfaction with the past) (p ≤ .001), and stress (p ≤ .019), significantly lower than ACM. Moreover, female ACD perceived more stress than female ACM (p ≤ .010), and male ACD (p ≤ .015). The group between 10-14-year-old at the time of the divorce rated significantly lower well-being (past) (p ≤ .035). In conclusion, the study suggests that Swedish ACD also suffer from long-term effects of divorce. Future research ought to investigate the matter further. / Skilsmässa har inte bara visat negativa långsiktiga effekter för skilsmässobarn (CD), utan också för vuxna skilsmässobarn (ACD). ACD har oftare ett sämre mentalt välbefinnande än vuxna med gifta föräldrar (ACM). Neurologisk forskning vidare påvisar att ACD också har lägre grundnivåer av ”stresshormonet” kortisol. Forskning kring svenska ACD är extremt sällsynt. Därför är det studiens mål att undersöka de möjliga långsiktiga effekterna av svenska ACD. Har ACD ett längre välbefinnande och upplever mer stress än ACM? Ett urval av 227 svenska deltagare (81 ACD och 146 ACM) var inkluderade. Majoriteten (75.7%) var mellan åldrarna 18-30 år gamla, 157 kvinnor och 70 män. En online enkät innehållandes Perceived Stress Scale (PSS), Temporal Satisfaction with Life Scale (TSWLS), och frågor kring skilsmässan distribuerades via sociala medier. Independent t-tests och one-way ANOVA analyser tillämpades för att jämföra ACD:s och ACM:s resultat. Studien fann att ACD uppskattade att deras välbefinnande (tillfredställelse med det förflutna) (p ≤ .001), och stress (p ≤ .019) signifikant längre än ACM. Fortsättningsvis, en signifikant skillnad upptäcktes där kvinnliga ACD upplevde mer stress än kvinnliga ACM (p ≤ .010), och manliga ACD (p ≤ .015). Gruppen mellan åldrarna 10–14 år gamla vid skilsmässan uppgav ett signifikant längre välbefinnande (förflutet) (p ≤ .035). Sammanfattningsvis, studien påvisar att svenska skilsmässobarn också lider av långsiktiga effekter från skilsmässa. Framtida forskning bör undersöka området vidare.
18

Från serum till plasma : Jämförelse av paratyroideahormon samt kortisol på Cobas 8000®

Mellberg, Maline January 2022 (has links)
Paratyroideahormon (PTH) och kortisol är två analyter som i dagsläget analyseras i serum med elektrokemilumenicense på instrumentet Cobas 8000® på Klinisk Kemi på Länssjukhuset i Kalmar. I framtiden är det planerat att övergå till att analysera dem i plasma. Syftet med projektet var att jämföra värden som erhållits för serum samt plasma för de båda analyterna och undersöka korrelationen mellan dem. Samtidigt utvärderades metodernas repeterbarhet samt eventuellt inflytande av oförutsebara faktorer på mätresultaten med en totalimprecisionsstudie.  PTH är ett peptidhormon som reglerar kalciumhomeostasen i kroppen. Dysfunktion i produktionen av PTH kan leda till osteoporos, hjärtarytmier, muskelkramper samt mentala störningar. Kortisol är ett livsnödvändigt steroidhormon som påverkar ämnesomsättningen och säkerställande det centrala nervsystemets energibehov i situationer med hög stress. Båda analyserna utförs rutinmässigt samt akut och en övergång till plasma skulle framför allt vara tidsbesparande och generera kortare svarstider. Jämförelsen av serum och plasma gjordes med 15 prover från patienter där ett serumrör samt ett plasmarör hade tagits vid samma provtillfälle. Detta resulterade i en determinationskoefficient (r2) som var för PTH 0,9988 och för kortisol 0,9993.  Totalimprecisionen uppskattades genom att analysera två serumkontroller för PTH och kortisol med sex replikat under fem dagar. Variationskoefficienten (CV) för de två PTH-serumkontrollerna var 3,9% för IM2 respektive 3,1% för IM3. För kortisol-serumkontrollerna var CV 2,1% för IM1 respektive 1,3% för IM2. För metoderna eftersträvades ett CV under 5%. Slutsatsen var att korrelationen mellan serum och plasma var mycket god samt att metoderna hade en bra stabilitet och repeterbarhet. / Parathyroid hormone (PTH) and cortisol are hormones involved in regulation of important mechanisms in the human body. PTH regulates the homeostasis of calcium and dysfunction in PTH production and release could lead to osteoporosis and arrythmia. Cortisol is involved in the metabolism and assures energy to the central nervous system in times of physiological stress. The concentration of these analytes is clinically determined by electrochemical luminescence on the immunochemical assay platform Cobas 8000®. In the laboratory of clinical chemistry in Kalmar the assays are performed on samples obtained from serum but changing to plasma assays would be more efficient and less time consuming. The aim of this project was to compare measured concentrations for PTH and cortisol using samples obtained from serum and plasma, respectively and to determine the correlation between the obtained results. The analytical precision was also evaluated to appreciate the influence of unpredictable events on the results.  The comparison between the results obtained from serum and plasma was performed by analysing 15 patient samples. Each serum and plasma sample were taken at the same time and from the same patient. The coefficient of determination for PTH was calculated to 0,9988 and for cortisol 0,9993 in serum and plasma, respectively. For the evaluation of the analytical precision, six replicates of two different serum controls for each analyte was assayed during six replicates for five days. In total of 30 replicates for each control. The coefficient of variation (CV) for PTH controls was 3,9% for IM2 and 3,1% for IM3. CV for cortisol was 2,1% for IM1 and 1,3% for IM2. The conclusion from this project was that there was a strong correlation between serum and plasma and both assays had good precision and repeatability.
19

Utvärdering av kortisol och TNF-α i saliv hos individer tidigare diagnostiserade med Covid-19 / Evaluation of cortisol and TNF-α in the saliva of individuals previously diagnosed with Covid- 19

Poolsri, Louise January 2021 (has links)
I december 2019 rapporterades fall av oidentifierad lunginflammation, senare känd som Covid-19. Antalet fall ökar fortfarande snabbt i världen och därmed utgör Covid-19 ett extraordinärt hot mot folkhälsan. Studier har visat en ökad mängd proinflammatoriska cytokiner TNF-α, associerade med andningssvårigheter samt en ökad kortisolproduktion. Utsöndring av kortisol och TNF-α är associerade med fysiska- och psykiska hälsoeffekter, sjukdomsgrad samt dödsfall av Covid-19. Syftet med studien var att undersöka utsöndringen av biomarkörerna kortisol och TNF-α i saliv hos individer tidigare diagnostiserade med Covid-19 samt hos individer utan diagnostiserad Covid-19 (kontrollgrupp). Det för att undersöka huruvida kvarvarande symtom kunde associeras till biomarkörerna. Studien inkluderade 40 individer, varav 20 individer tidigare diagnostiserade med Covid-19 samt 20 individer utan diagnostiserad Covid-19. Saliv och ett frågeformulär om deras allmänna hälsotillstånd och symtom kopplade till Covid-19 infektion samlades in och analyserades. Salivprover tagna på morgon analyserades med ELISA och resultatet jämfördes mellan grupperna. Inga signifikanta skillnader visade mellan grupperna gällande biomarkörer. Resultaten visade dessutom inga korrelation mellan symtom och biomarkörer samt att inga förhöjda nivåer av analyserade biomarkörer kan associeras med kvarvarande symtom efter en Covid-19 infektion. / A cluster of unidentified pneumonia cases, later known as Covid-19, were reported in December 2019. The number of Covid-19 cases is still rapidly increasing and poses an extraordinary threat to our public health. Studies have shown an increased level of the cytokine TNF-α, associated with severe respiratory symptoms as well as an increased cortisol production. Together associated with physical and mental health effects, disease severity and increased mortality of Covid-19. This study aimed to evaluate the secretion of cortisol and TNF-α in the saliva of individuals previously diagnosed with Covid-19 and individuals not diagnosed with Covid-19 (control group). This to examine whether the residual symptoms can be associated with the analyzed biomarkers. The study included 40 participants, 20 individuals diagnosed with Covid-19 and 20 individuals not diagnosed with Covid -19. Saliva and a questionnaire concerning their overall health and possible symptoms associated with Covid-19 infection were collected and analyzed. Saliva morning samples were analyzed with ELISA and results were compared between the groups. No significant differences were shown between the groups regarding the biomarkers. Also, the results showed no correlations between symptoms and biomarkers, nor elevated levels of analyzed biomarkers could be associated with residual symptoms after a Covid-19 infection.
20

The scanner as a stressor: Evidence from subjective and neuroendocrine stress parameters in the time course of a functional magnetic resonance imaging session

Mühlhan, Markus, Lüken, Ulrike, Wittchen, Hans-Ulrich, Kirschbaum, Clemens January 2011 (has links)
Subjects participating in magnetic resonance imaging (MRI) examinations regularly report anxiety and stress related reactions. This may result in impaired data quality and premature termination of scans. Moreover, cognitive functions and neural substrates can be altered by stress. While prior studies investigated pre–post scan differences in stress reactions only, the present study provides an in-depth analysis of mood changes and hormonal fluctuations during the time course of a typical fMRI session. Thirty-nine subjects participated in the study. Subjective mood, salivary alpha-amylase (sAA) and cortisol were assessed at six time points during the lab visit. Associations between hormonal data and neural correlates of a visual detection task were observed using a region of interest approach applied to the thalamic region. Mood and hormonal levels changed significantly during the experiment. Subjects were most nervous immediately after entering the scanner. SAA was significantly elevated after MRI preparation. A subgroup of n = 5 (12.8%) subjects showed pronounced cortisol responses exceeding 2.5 nmol/l. Preliminary fMRI data revealed an association between sAA levels and left thalamic activity during the first half of the experiment that disappeared during the second half. No significant correlation between cortisol and thalamic activity was observed. Results indicate that an fMRI experiment may elicit subjective and neuroendocrine stress reactions that can influence functional activation patterns.

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