Publications

142 Publications visible to you, out of a total of 142

Abstract

Not specified

Authors: M. L. Schroeter, J. Steiner, P. Schonknecht, K. Mueller

Date Published: 18th Mar 2014

Publication Type: Not specified

Human Diseases: mood disorder, neurotic disorder

Abstract (Expand)

A growing number of magnetic resonance imaging studies employ voxel-based morphometry (VBM) to assess structural brain changes. Recent reports have shown that image acquisition parameters may influence VBM results. For systematic evaluation, gray-matter-density (GMD) changes associated with aging were investigated by VBM employing acquisitions with different radiofrequency head coils (12-channel matrix coil vs. 32-channel array), different pulse sequences (MP-RAGE vs. MP2RAGE), and different voxel dimensions (1mm vs. 0.8mm). Thirty-six healthy subjects, classified as young, middle-aged, or elderly, participated in the study. Two-sample and paired t-tests revealed significant effects of acquisition parameters (coil, pulse sequence, and resolution) on the estimated age-related GMD changes in cortical and subcortical regions. Potential advantages in tissue classification and segmentation were obtained for MP2RAGE. The 32-channel coil generally outperformed the 12-channel coil, with more benefit for MP2RAGE. Further improvement can be expected from higher resolution if the loss in SNR is accounted for. Use of inconsistent acquisition parameters in VBM analyses is likely to introduce systematic bias. Overall, acquisition and protocol changes require careful adaptations of the VBM analysis strategy before generalized conclusion can be drawn.

Authors: D. P. Streitburger, A. Pampel, G. Krueger, J. Lepsien, M. L. Schroeter, K. Mueller, H. E. Moller

Date Published: 15th Feb 2014

Publication Type: Not specified

Abstract (Expand)

The high incidence of cognitive impairment in the ageing population, together with the challenges it imposes to health systems, raises the question of what affect working life has on cognitive abilities. The study, therefore, reviews recent work on the longitudinal impact of psychosocial work conditions on cognitive functioning and on dementia. Relevant articles were identified by a systematic literature search in PubMed and PsycINFO using a standardised search string and specific inclusion and exclusion criteria. We included articles reporting longitudinal effects that were investigated in cohort studies, case-control studies or randomised controlled trials in the working population. Two independent reviewers evaluated the studies in three subsequent phases: (i) title-abstract screening, (ii) full-text screening and (iii) checklist-based quality assessment.Methodical evaluation of the identified articles resulted in 17 studies of adequate quality. We found evidence for a protective effect of high job control and high work complexity with people and data on the risk of cognitive decline and dementia. Moreover, cognitively demanding work conditions seem to be associated with a decreased risk of cognitive deterioration in old age.Psychosocial work conditions can have an impact on cognitive functioning and even on the risk of dementia. As the world of work is undergoing fundamental changes, such as accelerated technological advances and an ageing working population, optimising work conditions is essential in order to promote and maintain cognitive abilities into old age.

Authors: F. S. Then, T. Luck, M. Luppa, M. Thinschmidt, S. Deckert, K. Nieuwenhuijsen, A. Seidler, S. G. Riedel-Heller

Date Published: 22nd Nov 2013

Publication Type: Not specified

Human Diseases: dementia

Abstract (Expand)

BACKGROUND: Minor depression (MinD) and mild cognitive impairment (MCI) are common disorders in late life that often coexist. The aim of the present review is to demonstrate prevalence rates of minor depression in older patients with and without MCI. METHODS: Electronic database searches were performed through Medline, ISI Web of Knowledge, Psycinfo, and Cochrane library. Two independent reviewers extracted the original studies based on inclusion criteria: representative study population aged 55 and older, diagnostics of MinD according to DSM. Data on prevalence rates, risk factors, comorbidity and health care usage were analyzed. RESULTS: Point prevalence for MinD is higher in medical settings (median 14.4%) than in the community-based settings (median 10.4%) and primary care patients (median 7.7%). Although minor depression is rarely investigated in elderly persons with MCI, nearly 20% of patients with MCI seem to suffer from MinD. No data was found on the prevalence of MCI in patients with MinD. Risk factors associated with MinD include female gender, history of cerebrovascular diseases, generalized anxiety disorder, loneliness, and long-term institutional care. LIMITATIONS: Methodological differences of included studies resulted in a broad range of prevalence rates. No data is shown regarding the prevalence of MCI in MinD group due to insufficient evidence. CONCLUSIONS: Our review indicates that MinD is frequent in elderly population. MCI among those subjects has not been sufficiently investigated. Future studies based on clinical structured interviews should be performed in longitudinal design in order to differentiate late-life depression from progressive MCI or early manifestation of Alzheimer's disease.

Authors: M. Polyakova, N. Sonnabend, C. Sander, R. Mergl, M. L. Schroeter, J. Schroeder, P. Schonknecht

Date Published: 10th Oct 2013

Publication Type: Not specified

Human Diseases: mental depression

Abstract (Expand)

Introduction LIFE is a large epidemiological study aiming at causes of common civilization diseases including adiposity, dementia, and depression. Participants of the study are probands and patients. Probands are randomly selected and invited from the set of Leipzig (Germany) inhabitants while patients with known diseases are recruited from several local hospitals. The management of these participants, their invitation and contact after successful attendance as well as the support of nearly all ambulance processes requires a complex ambulance management. Each participant is examined by a set of investigation instruments including interviews, questionnaires, device-specific investigations, specimen extrac- tions and analyses. This necessitates a complex management of the participantspecific examination program but also specific input forms and systems allowing to capture administrative (measurement and process environment or specific set-ups) and scientific data. Additionally, the taken and prepared specimens need to be labeled and registered from which participant they stem and in which fridge or bio-tank they are stored. At the end, all captured data from ambu- lance management, investigation instruments and laboratory analyses need to be integrated before they can be analyzed. These complex processes and requirements necessitate a comprehensive IT-infrastructure. Methods Our IT-infrastructure modularly consists of several software applications. A main application is responsible for the complex participant and ambulance man- agement. The participant management cope with selected participant data and contact information. To protect participant’s privacy, a participant identifier (PID) is created for each participant that is associated to all data which is managed and captured in the following. In ambulance management, each participant is associated with a predefined investigation program. This investigation program is represented in our systems by a tracking card that is available as print-out and electronically. The electronic version of tracking cards is utilized by two software applications, the Assessment Battery and the CryoLab. The former system coordinates the input of scientific data into online input forms. The input forms are designed in the open source system LimeSurvey. Moreover, the Assessment Battery is used to monitor the input process, i.e., it shows which investigations are already completed and which of them are still to do. The Cryolab system registers and tracks all taken specimens and is used to annotate extraction and specific preparation processes, e.g., for DNA isolation. Moreover, it tracks specimen storage in fridges and bio-tanks. A central component is the metadata repository collecting metadata from ambulance management and data input systems. It is the base for the integra- tion of relevant scientific data into a central research database. The integration follows a mapping-based approach. The research database makes raw data and special pre-computations called derivatives available for later data analysis. Results & Discussion We designed and implemented a complex and comprehensive IT-infrastructure for the epidemiological research in LIFE. This infrastructure consists of several software applications which are loosely coupled over specified interfaces. Most of the software applications are new implementations; only for capturing scientific data external software application are applied.

Authors: Toralf Kirsten, A. Kiel, M. Kleinert, R. Speer, M. Rühle, Hans Binder, Markus Löffler

Date Published: 30th Sep 2013

Publication Type: Not specified

Abstract (Expand)

Introduction LIFE is a epidemiological study aiming at discovering causes of common disorders as well as therapy and diagnostic possibilities. It applies a huge set (currently more then 400) of complex instruments including different kinds of interviews, questionnaires, and technically founded investigations on thousands of Leipzig inhabitants. Correlations in data, e.g., between diseases on the one hand and a combination of life conditions on the other requires high quality data. Data errors affect this data quality. However, avoiding every error is nearly impossible. Therefore, the captured data routinely needs to be validated and revised (curated) in case of error. Methods From the data-perspective, we differentiate between two main types of data errors, syntax or format errors and semantic errors. Syntax errors mostly occur when the data needs to be converted to change its data type, e.g., from text to number or from text to date/time fields. This is often the case when data is captured as text by the data input system but should be centrally managed and analyzed in a different format. Hence, the data conversion is only successful when the input data contains the data in the right format. Data conversion is applied when the data is transfered from data input systems to the central research database collecting all captured data in an integrated and harmonized form. Corrupted data that cannot be converted to the target data type is replaced by a missing value (also called null value, nil etc.). The definition of a default value is not sufficient since the default usually depends on the corresponding question or measurement input field and can strain analysis results when they are not concerned. Moreover, the definition process for every question/input field would be to time-consuming. Semantic errors are much harder to detect than syntax errors. Typically, they are semantically implausible outliers or are part of other artefacts, e.g.,when data of two input fields is mixed up. Currently, we let the detection of semantic errors to a epidemiological quality analysis that is performed by several statisticians. Conversely, syntax errors can be easily technically detected; they are logged when they occur in the process of transferring data from data input systems to the central research database. With respect to both types of errors, syntax and semantic errors, we designed and implemented a software application called Curation-DB allowing to curate (adapt and change) data. In particular, the system lists the logged syntax errors occurring during the data conversion step daily at night. A user can adapt the current input value by specifying a new (target) value for a listed syntax problem. With this specification, the corresponding input value is replaced by the specified value before the next conversion step is started. This specification process can be iteratively applied for a corresponding input value when the syntax problem is not solved by the current specification. The semantic errors need to be first detected separately. Then, a user can specify value changes replacing an existing value with the new specified one. Results & Discussion The Curation-DB application is already in use. Currently, selected quality managers routinely check the listed syntax errors. There are currently more than 2000 of such errors curated. In near future, we will extend this software to manage rules validating research data semantically to automatically detect obvious semantic errors.

Authors: J. Wagner, A. Kiel, Toralf Kirsten

Date Published: 30th Sep 2013

Publication Type: Not specified

Abstract (Expand)

OBJECTIVES: Persons with multiple sclerosis (PwMS) experience health-related quality of life (HRQoL) problems greatly differing across Europe, and the European Union (EU) faces deep inequalities in MS management from country to country. Through the establishment of a European MS Register (EUReMS), an effective action is proposed to improve the overall knowledge on MS and support effective intervention programmes at EU and national political level. EUReMS aims to achieve consensus on its mission and vision, to define existing data providers, to develop models driving future MS health policies and research, to develop an information technology (IT) infrastructure for a data set, to develop a European shared governance and to secure providers' data provision into EUReMS. MATERIALS AND METHODS: EUReMS is meant to build on a minimum set of core data from existing national and regional population-based MS registries and from PwMS' perspectives. EUReMS' main partner is the European MS Platform (EMSP) acting in collaboration with associated and collaborating European partners. RESULTS: EUReMS was launched in July 2011. A Consensus Statement on purposes, vision, mission and strategies was produced in December 2011, and a comprehensive survey on existing MS data collections in Europe has been performed, and the EUReMS data mask is currently being discussed. CONCLUSIONS: EUReMS will represent a tool to provide up to date, comparable and sustainable MS data through an effective and credible register, which will encourage extensive knowledge building of MS, more equitable policies and higher standards in MS treatment and services.

Authors: M. Pugliatti, D. Eskic, T. Mikolcic, D. Pitschnau-Michel, K. M. Myhr, J. Sastre-Garriga, S. Otero, L. Wieczynska, C. Torje, E. Holloway, O. Rienhoff, T. Friede, K. Buckow, D. Ellenberger, J. Hillert, A. Glaser, P. Flachenecker, J. Fuge, T. Schyns-Liharska, E. Kasilingam, A. Moretti, C. Thalheim

Date Published: 3rd Jan 2013

Publication Type: Not specified

Human Diseases: dementia, Alzheimer's disease

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