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188 Publications visible to you, out of a total of 188
Reliability of 3D laser-based anthropometry and comparison with classical anthropometry
Genetical Statistics and Systems Biology

Abstract (Expand)

Anthropometric quantities are widely used in epidemiologic research as possible confounders, risk factors, or outcomes. 3D laser-based body scans (BS) allow evaluation of dozens of quantities in short … time with minimal physical contact between observers and probands. The aim of this study was to compare BS with classical manual anthropometric (CA) assessments with respect to feasibility, reliability, and validity. We performed a study on 108 individuals with multiple measurements of BS and CA to estimate intra- and inter-rater reliabilities for both. We suggested BS equivalents of CA measurements and determined validity of BS considering CA the gold standard. Throughout the study, the overall concordance correlation coefficient (OCCC) was chosen as indicator of agreement. BS was slightly more time consuming but better accepted than CA. For CA, OCCCs for intra- and inter-rater reliability were greater than 0.8 for all nine quantities studied. For BS, 9 of 154 quantities showed reliabilities below 0.7. BS proxies for CA measurements showed good agreement (minimum OCCC \textgreater 0.77) after offset correction. Thigh length showed higher reliability in BS while upper arm length showed higher reliability in CA. Except for these issues, reliabilities of CA measurements and their BS equivalents were comparable.

Authors: Andreas Kuehnapfel, Peter Ahnert, Markus Loeffler, Anja Broda, Markus Scholz

Date Published: 1st May 2016

Publication Type: Journal article

Genome-wide association analysis of actigraphic sleep phenotypes in the LIFE Adult Study.
LIFE Adult, Genetical Statistics and Systems Biology

Abstract (Expand)

The genetic basis of sleep is still poorly understood. Despite the moderate to high heritability of sleep-related phenotypes, known genetic variants explain only a small proportion of the phenotypical … variance. However, most previous studies were based solely upon self-report measures. The present study aimed to conduct the first genome-wide association (GWA) of actigraphic sleep phenotypes. The analyses included 956 middle- to older-aged subjects (40-79 years) from the LIFE Adult Study. The SenseWear Pro 3 Armband was used to collect 11 actigraphic parameters of night- and daytime sleep and three parameters of rest (lying down). The parameters comprised measures of sleep timing, quantity and quality. A total of 7 141 204 single nucleotide polymorphisms (SNPs) were analysed after imputation and quality control. We identified several variants below the significance threshold of P </= 5x 10(-8) (not corrected for analysis of multiple traits). The most significant was a hit near UFL1 associated with sleep efficiency on weekdays (P = 1.39 x 10(-8) ). Further SNPs were close to significance, including an association between sleep latency and a variant in CSNK2A1 (P = 8.20 x 10(-8) ), a gene known to be involved in the regulation of circadian rhythm. In summary, our GWAS identified novel candidate genes with biological plausibility being promising candidates for replication and further follow-up studies.

Authors: J. Spada, M. Scholz, H. Kirsten, T. Hensch, K. Horn, P. Jawinski, C. Ulke, R. Burkhardt, K. Wirkner, M. Loeffler, U. Hegerl, C. Sander

Date Published: 30th Apr 2016

Publication Type: Journal article

Relationship Between Determinants of Arterial Stiffness Assessed by Diastolic and Suprasystolic Pulse Oscillometry: Comparison of Vicorder and Vascular Explorer.
Genetical Statistics and Systems Biology, LIFE Heart

Abstract (Expand)

Pulse wave velocity (PWV) and augmentation index (AI) are independent predictors of cardiovascular health. However, the comparability of multiple oscillometric modalities currently available for their … assessment was not studied in detail. In the present study, we aimed to evaluate the relationship between indices of arterial stiffness assessed by diastolic and suprasystolic oscillometry.In total, 56 volunteers from the general population (23 males; median age 70 years [interquartile range: 65-72 years]) were recruited into observational feasibility study to evaluate the carotid-femoral/aortic PWV (cf/aoPWV), brachial-ankle PWV (baPWV), and AI assessed by 2 devices: Vicorder (VI) applying diastolic, right-sided oscillometry for the determination of all 3 indices, and Vascular explorer (VE) implementing single-point, suprasystolic brachial oscillometry (SSBO) pulse wave analysis for the assessment of cfPWV and AI. Within- and between-device correlations of measured parameters were analyzed. Furthermore, agreement of repeated measurements, intra- and inter-observer concordances were determined and compared for both devices.In VI, both baPWV and cfPWV inter-correlated well and showed good level of agreement with bilateral baPWV measured by VE (baPWV[VI]-baPWV[VE]R: overall concordance correlation coefficient [OCCC] = 0.484, mean difference = 1.94 m/s; cfPWV[VI]-baPWV[VE]R: OCCC = 0.493, mean difference = 1.0 m/s). In contrast, SSBO-derived aortic PWA (cf/aoPWA[VE]) displayed only weak correlation with cfPWV(VI) (r = 0.196; P = 0.04) and ipsilateral baPWV (cf/aoPWV[VE]R-baPWV[VE]R: r = 0.166; P = 0.08). cf/aoPWA(VE) correlated strongly with AI(VE) (right-sided: r = 0.725, P < 0.001). AI exhibited marginal between-device agreement (right-sided: OCCC = 0.298, mean difference: 6.12%). All considered parameters showed good-to-excellent repeatability giving OCCC > 0.9 for 2-point-PWV modes and right-sided AI(VE). Intra- and inter-observer concordances were similarly high except for AI yielding a trend toward better reproducibility in VE (interobserver-OCCC[VI] vs [VE] = 0.774 vs 0.844; intraobserver-OCCC[VI] vs [VE] = 0.613 vs 0.769).Both diastolic oscillometry-derived PWV modes, and AI measured either with VI or VE, are comparable and reliable alternatives for the assessment of arterial stiffness. Aortic PWV assessed by SSBO in VE is not related to the corresponding indices determined by traditional diastolic oscillometry.

Authors: A. Teren, F. Beutner, K. Wirkner, M. Loffler, M. Scholz

Date Published: 11th Mar 2016

Publication Type: Journal article

Prevalence of BRCA1/2 germline mutations in 21 401 families with breast and ovarian cancer.
GC-HBOC - German Consortium for Hereditary Breast and Ovarian Cancer

Abstract (Expand)

PURPOSE: To characterise the prevalence of pathogenic germline mutations in BRCA1 and BRCA2 in families with breast cancer (BC) and ovarian cancer (OC) history. PATIENTS AND METHODS: Data from 21 401 … families were gathered between 1996 and 2014 in a clinical setting in the German Consortium for Hereditary Breast and Ovarian Cancer, comprising full pedigrees with cancer status of all individual members at the time of first counselling, and BRCA1/2 mutation status of the index patient. RESULTS: The overall BRCA1/2 mutation prevalence was 24.0% (95% CI 23.4% to 24.6%). Highest mutation frequencies were observed in families with at least two OCs (41.9%, 95% CI 36.1% to 48.0%) and families with at least one breast and one OC (41.6%, 95% CI 40.3% to 43.0%), followed by male BC with at least one female BC or OC (35.8%; 95% CI 32.2% to 39.6%). In families with a single case of early BC (<36 years), mutations were found in 13.7% (95% CI 11.9% to 15.7%). Postmenopausal unilateral or bilateral BC did not increase the probability of mutation detection. Occurrence of premenopausal BC and OC in the same woman led to higher mutation frequencies compared with the occurrence of these two cancers in different individuals (49.0%; 95% CI 41.0% to 57.0% vs 31.5%; 95% CI 28.0% to 35.2%). CONCLUSIONS: Our data provide guidance for healthcare professionals and decision-makers to identify individuals who should undergo genetic testing for hereditary breast and ovarian cancer. Moreover, it supports informed decision-making of counselees on the uptake of genetic testing.

Authors: K. Kast, K. Rhiem, B. Wappenschmidt, E. Hahnen, J. Hauke, B. Bluemcke, V. Zarghooni, N. Herold, N. Ditsch, M. Kiechle, M. Braun, C. Fischer, N. Dikow, S. Schott, N. Rahner, D. Niederacher, T. Fehm, A. Gehrig, C. Mueller-Reible, N. Arnold, N. Maass, G. Borck, N. de Gregorio, C. Scholz, B. Auber, R. Varon-Manteeva, D. Speiser, J. Horvath, N. Lichey, P. Wimberger, S. Stark, U. Faust, B. H. Weber, G. Emons, S. Zachariae, A. Meindl, R. K. Schmutzler, C. Engel

Date Published: 2nd Mar 2016

Publication Type: Journal article

Human Diseases: breast cancer, ovarian cancer

Modeling combined chemo- and immunotherapy of high-grade non-Hodgkin lymphoma.
LIFE - Leipzig Research Center for Civilization Diseases, Genetical Statistics and Systems Biology

Abstract (Expand)

Moderate, but not massive intensification of CHOP-21 improves outcome in aggressive non-Hodgkin lymphoma. Adding immunotherapy with Rituximab was a break-through, but levels differences in chemotherapy. … Ongoing trials attempt to optimize R-CHOP type regimens. We present a mathematical model of chemo-immunotherapy to explain published and aiming at predicting future trials comparing R-CHOP variants. We hypothesize that, for cure, the immune system must dominate residual tumor cells at the end of treatment. Chemotherapy reduces both tumor and immune cells. Rituximab immunotherapy boosts the immune response. We translate this reasoning into a differential equations model. Model parameters are estimated using data of randomized clinical trials in elderly patients. The model explains observed hazard ratios between treatments. It explains why too intense chemotherapy could be detrimental. The model is validated predicting six published independent studies. As an application, we varied treatment schedules and predict that current R-CHOP variants have only limited optimization potential.

Authors: K. Rosch, M. Scholz, D. Hasenclever

Date Published: 16th Dec 2015

Publication Type: Not specified

Human Diseases: lymphoma

The role of HPV RNA transcription, immune response-related gene expression and disruptive TP53 mutations in diagnostic and prognostic profiling of head and neck cancer.
LIFE HNC - Head and Neck Cancer Group, Genetical Statistics and Systems Biology

Abstract (Expand)

Stratification of head and neck squamous cell carcinomas (HNSCC) based on HPV16 DNA and RNA status, gene expression patterns, and mutated candidate genes may facilitate patient treatment decision. We … characterize head and neck squamous cell carcinomas (HNSCC) with different HPV16 DNA and RNA (E6*I) status from 290 consecutively recruited patients by gene expression profiling and targeted sequencing of 50 genes. We show that tumors with transcriptionally inactive HPV16 (DNA+ RNA-) are similar to HPV-negative (DNA-) tumors regarding gene expression and frequency of TP53 mutations (47%, 8/17 and 43%, 72/167, respectively). We also find that an immune response-related gene expression cluster is associated with lymph node metastasis, independent of HPV16 status and that disruptive TP53 mutations are associated with lymph node metastasis in HPV16 DNA- tumors. We validate each of these associations in another large data set. Four gene expression clusters which we identify differ moderately but significantly in overall survival. Our findings underscore the importance of measuring the HPV16 RNA (E6*I) and TP53-mutation status for patient stratification and identify associations of an immune response-related gene expression cluster and TP53 mutations with lymph node metastasis in HNSCC.

Authors: G. Wichmann, M. Rosolowski, K. Krohn, M. Kreuz, A. Boehm, A. Reiche, U. Scharrer, D. Halama, J. Bertolini, U. Bauer, D. Holzinger, M. Pawlita, J. Hess, C. Engel, D. Hasenclever, M. Scholz, P. Ahnert, H. Kirsten, A. Hemprich, C. Wittekind, O. Herbarth, F. Horn, A. Dietz, M. Loeffler

Date Published: 15th Dec 2015

Publication Type: Not specified

Human Diseases: head and neck cancer

Genetic variants of lipase activity in chronic pancreatitis
Genetical Statistics and Systems Biology

Abstract

Not specified

Authors: Holger Kirsten, Markus Scholz, Peter Kovacs, Harald Grallert, Annette Peters, Konstantin Strauch, Josef Frank, Marcella Rietschel, Markus M. Nöthen, Heiko Witt, Jonas Rosendahl

Date Published: 8th Dec 2015

Publication Type: Journal article

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