A pilot study of hair and cytokine balance alteration in healthy young women under major exam stress

Mouse models show that experimental stress mimicking prolonged life-stress exposure enhances neurogenic inflammation, induces adaptive immunity cytokine- imbalance characterized by a shift to Type 1 T-helper cell cytokines and increases apoptosis of epithelial cells. This affects hair growth in otherwise healthy animals. In this study, we investigate whether a prolonged naturalistic life-stress exposure affects cytokine balance and hair parameters in healthy humans. 33 (18 exam, 15 comparison) female medical students with comparable sociobiological status were analyzed during a stressful final examination period, at three points in time (T) 12 weeks apart. T1 was before start of the learning period, T2 between the three-day written exam and an oral examination, and T3 after a 12 week rest and recovery from the stress of the examination period. Assessments included: self-reported distress and coping strategies (Perceived Stress Questionnaire [PSQ], Trier Inventory for the Assessment of Chronic Stress [TICS]), COPE), cytokines in supernatants of stimulated peripheral blood mononucleocytes (PBMCs), and trichogram (hair cycle and pigmentation analysis). Comparison between students participating in the final medical exam at T2 and non-exam students, revealed significantly higher stress perception in exam students. Time-wise comparison revealed that stress level, TH1/TH2 cytokine balance and hair parameters changed significantly from T1 to T2 in the exam group, but not the control. However, no group differences were found for cytokine balance or hair parameters at T2. The study concludes that in humans, naturalistic stress, as perceived during participation in a major medical exam, has the potential to shift the immune response to TH1 and transiently hamper hair growth, but these changes stay within a physiological range. Findings are instructive for patients suffering from hair loss in times of high stress. Replication in larger and more diverse sample populations is required, to assess suitability of trichogram analysis as biological outcome for stress studies

Development of psychometric instruments in studies of different disease groups with a special focus on auto-destructive syndromes

Titelblatt, Inhaltsverzeichnis Einleitung Eigene Arbeiten Originalarbeiten Diskussion LiteraturverzeichnisDie Arbeiten dieser Habilitation widmen sich der Entwicklung und Optimierung psychologisch diagnostischer Verfahren für die Integrierte Psychosomatik und angrenzende gesundheitspsychologische Disziplinen. Die Verfahren erfassen Konstrukte aus den Bereichen Lebensqualität, Belastungserleben und Ressourcen, die in vielfältigen psychosomatischen und gesundheitspsychologischen Modellen und für Therapieevaluation und Prognose eine Rolle spielen. Ein klinischer Exkurs vertieft die Diagnostik autodestruktiver Syndrome. Entwickelt wurde eine deutsche Fassung des Perceived Stress Questionnaire . Berichtet werden die empirischen Ergebnisse zur Adaptation, psychometrischen Validierung und Testung der strukturellen Invarianz in verschiedenen Stichproben. Wie die meisten psychometrischen Fragebögen beruht dieses Verfahren auf der Klassischen Testtheorie (KTT). Dazu kontrastierend wurde ein Verfahren zur Messung von Depression entwickelt, welches auf der probabilistischen Testtheorie beruht und einen computeradaptiven Testalgorithmus (CAT) nutzt. Psychometrische Diagnostik dient neben der Deskription, der Klassifikation und der Erklärung auch der Therapieevaluation und der Prognose. Verdeutlicht wird dies in einer Evaluation der langfristigen Effekte stationärer psychosomatischer Behandlung. Als Evaluationskriterien wurden neben Merkmalen der gesundheitsbezogenen Lebensqualität so genannte objektive Merkmale herangezogen, hier Arbeitsunfähigkeiten und Krankenhaustage nach Angaben der Krankenkassen. Generalisierte Erwartungshaltungen der Person (Selbstwirksamkeit, Optimismus, Pessimismus) waren relevante Prädiktoren. Für autodestruktive Syndrome herrscht Uneinigkeit, wie diese definiert, klassifiziert und diagnostiziert werden sollen, und es herrscht ein Mangel an empirisch überprüften Messinstrumenten. In einer Übersichtsarbeit wurden zwei Fallbeispiele der eigenen Behandlung dargestellt und einer vorliegenden Typologie selbstschädigenden Verhaltens zugeordnet. Willenberg et al. legten zu dieser Typologie ein klinisches Fremdbeurteilungsverfahren zur Diagnostik selbstschädigenden Verhaltens vor. In Studien an über 2000 Patienten der Psychosomatik wurde dieses Instrument eingesetzt und psychometrisch geprüft. Es wurden Häufigkeiten, Verteilungsmuster und psychopathologische Korrelate ermittelt. Um multimodale Diagnostik zu ermöglichen wurden zwei amerikanische Selbstauskunftsverfahren zu selbstverletzendem und suizidalem Verhalten übersetzt, adaptiert, psychometrisch überprüft und gegenüber dem Fremdbeurteilungsbogen validiert. Computer-adaptives Testen auf Grundlage probabilistischer Messmodelle bietet gegenüber KTT-basierter Methodik erhebliche Vorteile hinsichtlich Messgenauigkeit und Ökonomie. Für komplexe Fragestellungen, wie die Diagnostik teils offenen, teils verheimlichten autodestruktiven Verhaltens oder die Evaluation psychosomatischer Behandlung, bringt Multimodalität, also die Einbeziehung unterschiedlicher Datenquellen und Datenebenen, je spezifische Information und sollte wo immer möglich realisiert werden.This work embraces studies that aim to develop and improve psychological assessment in the context of Psychosomatic Medicine, Health Psychology, and neighbouring fields. The instruments assess aspects of health-related quality of life, stress, and resources constructs that play a crucial role in various psychosomatic and health psychology models as well as in outcome evaluation and prognosis. A special clinical focus is on the assessment of auto-destructive behaviour. A German version of the Perceived Stress Questionnaire is introduced. Empirical results on adaptation, psychometrical evaluation und testing of structural invariance across different samples are reported. This questionnaire, as most questionnaires, is based on Classical Test Theory (CTT). Contrasting to this approach, we developed an assessment instrument for depression which is based on Item Response Theory and makes use of a computer-adaptive testing algorithm (CAT). Psychometric assessment serves several purposes: description, classification, and explication, furthermore outcome evaluation and prognosis. A study on the long-term effects of psychosomatic in-patient treatment exemplifies the latter purposes. Alongside with the usual patient-reported outcome criteria the study included so called objective criteria, in this case work leave and hospital days as recorded by insurance companies. Generalized expectancies of the person (optimism, pessimism, and self-efficacy) were relevant outcome predictors. Regarding auto-destructive syndromes, as yet, there is no common agreement on their definition, classification and diagnostic assessment. Empirically evaluated diagnostic instruments are hardly available. In a review of behaviour therapy approaches, two case histories from the author s own psychotherapeutic work were included. They illustrate two types out of an existing typological classification system. Based on this system, Willenberg et al. designed an expert-rated documentation form for the assessment of self-harmful behaviours. In our studies of over 2000 psychosomatic patients, we used this rating form and evaluated its psychometric properties. We investigated the occurrence of self-destructive behaviour and various psychopathological correlates. To lay the path for a multimodal approach, two American self-rated instruments on self-harm and suicidal behaviour were translated into German, adapted, psychometrically evaluated and tested along with the clinician rating scale. Compared to CTT-based instruments probabilistic test approaches and the use of computer-adaptive testing algorithms offer relevant advantages with regard to measurement precision and economy. The assessment of complex clinical problems, like partly open partly secretive auto-destructive behaviours, or like the outcome evaluation of psychosomatic treatment, calls for a complex assessment approach. Whenever possible, different kinds of data should be included and different data sources used

Impact of cross-calibration methods on the interpretation of a treatment comparison study using 2 depression scales

BACKGROUND: Many questionnaires assessing depressive symptoms are available. Most of these questionnaires are constructed based on classical test theory, making comparisons of individual scores difficult. Item response theory (IRT) allows the comparison of scores from different instruments. In this study, the impact of IRT-based cross-calibration methods on the results of a treatment outcome study was evaluated using 2 instruments. METHODS: Data collected during admission and discharge procedures from 1066 inpatients in 2 psychosomatic clinics using different depression measures were analyzed. To achieve comparability across the applied depression measures, we used an IRT-based conversion table to transform scores from one instrument\u27s scale to the other. Latent trait values were also estimated using different instruments in each clinic. We compared these methods to the traditional approach of using the same instrument in both clinics and examined their effects on the statistical analyses. RESULTS: There was no substantial change in the interpretation of the study results when different instruments were used. However, F values, P values, and effect sizes in the analysis of variance changed significantly. This might be attributed to differences in the content or measurement properties of the instruments. Interestingly, no difference was observed between use of transformed sum scores and latent trait values. CONCLUSIONS: IRT cross-calibration methods are a convenient way to enhance the comparability of questionnaire data in applied clinical settings but seem not to be able to overcome differences in measurement properties of the instruments. As these differences can lead to biased results, there is a need for further research into more advanced techniques

Development of a method for predicting the residual life of electric traction motor brushes

Актуальность исследования определяется необходимостью повышения надежности работы подвижного состава (карьерных самосвалов), обеспечивающего добычу угля открытым способом. Такую же актуальность данная проблема имеет в отрасли железнодорожных перевозок - на подвижном составе железных дорог. Безотказность работы подвижного состава определяется надежностью функционирования его отдельных узлов. Как известно из анализа отказов подвижного состава транспортных средств с коллекторными тяговыми электродвигателями, одним из критичных элементов для них является щеточный аппарат. Известные способы прогнозирования не используют в полной мере возможности современных бортовых систем мониторинга режимов работы тяговых электродвигателей. Следовательно, актуальной задачей является повышение точности прогнозирования остаточного ресурса электрощеток за счет учета показателей режимов работы, фиксируемых бортовой системой мониторинга. Цель: разработка способа прогнозирования остаточного ресурса электрощеток тяговых электродвигателей карьерных самосвалов с учетом показателей режимов работы, получаемых от бортовой системы мониторинга. Объект: электрощетки тяговых электродвигателей карьерных самосвалов. Методы: проведение математического анализа данных бортовых систем мониторинга, математическое моделирование процесса изнашивания электрощеток, синтез способа прогнозирования остаточного ресурса щеток тягового электродвигателя. Результаты. Разработан способ прогнозирования остаточного ресурса щеток тяговых электродвигателей, позволяющий учесть показатели режимов работы в условиях реальной эксплуатации. Повышена точность определения остаточного ресурса электрощеток за счет применения в процессе прогнозирования массивов данных, полученных от бортовой системой мониторинга. Разработан алгоритм прогнозирования, который может быть применен в бортовых электронных системах подвижного состава для индикации остаточного ресурса электрощеток.The relevance of the research is caused by the need to improve the rolling stock (quarry dump trucks) operation reliability, providing openpit coal mining. This problem is also relevant in the railway transportation industry - on the rolling stock of railways. The reliability of the rolling stock is determined by the reliability of the functioning of its individual components. As it is known from the analysis of failures of rolling stock of vehicles with collector traction motors, one of the critical elements for them is the brush machine. The known methods of forecasting do not fully use the capabilities of modern on-board systems for monitoring the operating modes of traction motors. Therefore, an urgent task is to increase the accuracy of predicting the residual life of electric brushes by taking into account the indicators of the operating modes recorded by the on-board monitoring system. The main aim of the research is to develop a method for predicting the residual life of electric brushes of traction electric motors of mining dump trucks, taking into account the indicators of operating modes obtained from the on-board monitoring system. Objects: electric brushes of traction electric motors of mining dump trucks. Methods: mathematical analysis of data from on-board monitoring systems, mathematical modeling of electric brushes wear, synthesis of a method for predicting the residual life of traction motor brushes. Results. A method for predicting the residual life of the brushes of traction motors has been developed, which allows taking into account the indicators of the operating modes in real operation conditions. The accuracy of determining the residual life of electrical panels is increased due to the use of data arrays obtained from the on-board monitoring system in forecasting. The authors have developed the prediction algorithm that can be used in on-board electronic systems of rolling stock to indicate the residual life of electric brushes

Hair and stress: A pilot study of hair and cytokine balance alteration in healthy young women under major exam stress.

Mouse models show that experimental stress mimicking prolonged life-stress exposure enhances neurogenic inflammation, induces adaptive immunity cytokine-imbalance characterized by a shift to Type 1 T-helper cell cytokines and increases apoptosis of epithelial cells. This affects hair growth in otherwise healthy animals. In this study, we investigate whether a prolonged naturalistic life-stress exposure affects cytokine balance and hair parameters in healthy humans. 33 (18 exam, 15 comparison) female medical students with comparable sociobiological status were analyzed during a stressful final examination period, at three points in time (T) 12 weeks apart. T1 was before start of the learning period, T2 between the three-day written exam and an oral examination, and T3 after a 12 week rest and recovery from the stress of the examination period. Assessments included: self-reported distress and coping strategies (Perceived Stress Questionnaire [PSQ], Trier Inventory for the Assessment of Chronic Stress [TICS]), COPE), cytokines in supernatants of stimulated peripheral blood mononucleocytes (PBMCs), and trichogram (hair cycle and pigmentation analysis). Comparison between students participating in the final medical exam at T2 and non-exam students, revealed significantly higher stress perception in exam students. Time-wise comparison revealed that stress level, TH1/TH2 cytokine balance and hair parameters changed significantly from T1 to T2 in the exam group, but not the control. However, no group differences were found for cytokine balance or hair parameters at T2. The study concludes that in humans, naturalistic stress, as perceived during participation in a major medical exam, has the potential to shift the immune response to TH1 and transiently hamper hair growth, but these changes stay within a physiological range. Findings are instructive for patients suffering from hair loss in times of high stress. Replication in larger and more diverse sample populations is required, to assess suitability of trichogram analysis as biological outcome for stress studies

Assessment of stress perception and acquisition of samples to assess biological outcomes in exam versus comparison students.

<p>Note that T2 took place within the first two weeks after the written and before the oral part of the exam. A salivary cortisol profile was obtained the day prior to T2 to confirm altered cortisol diurnal profile in the exam group. In addition to assessing subacute stress perception, participants were assessed for mental health, other parameters of psychological strain and coping/resources, to ensure good health and resourcefulness. Abbreviations: <b>COPE</b>—coping strategies, <b>DHUS</b>—Daily Hassles and Uplifts Scales (Kanner et al., 1981), <b>HADS</b>—Hospital Anxiety and Depression Scale, <b>IES</b>—Impact of Event Scale, <b>PSQ</b>—Perceived Stress Questionnaire, <b>SOMS</b>—Screening for Somatoform Symptoms, <b>TICS</b>—Trier Inventory for the Assessment of Chronic Stress.</p

Self report assessment of stress perception and emotional strain in female medical students during their final exam.

<p>Graphs (a)-(f) show self-report data assessed at the following points in time (T): baseline, twelve weeks prior to the exam and before the learning period started (1); within the first and second week after the written part of the exam and before test results were released (2); and twelve weeks after the completion of the exam (3). Graph (g) shows cortisol measurements in saliva samples taken on the day prior to T2. Samples were processed to assess diurnal cortisol secretion as described below in the Materials and Methods section. (a)-(g): N = 18 in exam group, N = 15 in comparison group. Mean values and SEM are shown. Mann Whitney U tests were used to examine differences between group means at distinct points in time, Kruskal-Wallis tests with post-hoc Dunn's tests corrected for multiple comparisons to examine differences between different points in time within one group. P-values < 0.1 –one asterix in brackets, <0.05 –one asterix, < 0.01—two asterix, < 0.001—three asterix.</p