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Identification of adipokine clusters related to parameters of fat mass, insulin sensitivity and inflammation
Genetical Statistics and Systems Biology

Abstract (Expand)

In obesity, elevated fat mass and ectopic fat accumulation are associated with changes in adipokine secretion, which may link obesity to inflammation and the development of insulin resistance. However, … relationships among individual adipokines and between adipokines and parameters of obesity, glucose metabolism or inflammation are largely unknown. Serum concentrations of 20 adipokines were measured in 141 Caucasian obese men (n = 67) and women (n = 74) with a wide range of body weight, glycemia and insulin sensitivity. Unbiased, distance-based hierarchical cluster analyses were performed to recognize patterns among adipokines and their relationship with parameters of obesity, glucose metabolism, insulin sensitivity and inflammation. We identified two major adipokine clusters related to either (1) body fat mass and inflammation (leptin, ANGPTL3, DLL1, chemerin, Nampt, resistin) or insulin sensitivity/hyperglycemia, and lipid metabolism (vaspin, clusterin, glypican 4, progranulin, ANGPTL6, GPX3, RBP4, DLK1, SFRP5, BMP7, adiponectin, CTRP3 and 5, omentin). In addition, we found distinct adipokine clusters in subgroups of patients with or without type 2 diabetes (T2D). Logistic regression analyses revealed ANGPTL6, DLK1, Nampt and progranulin as strongest adipokine correlates of T2D in obese individuals. The panel of 20 adipokines predicted T2D compared to a combination of HbA1c, HOMA-IR and fasting plasma glucose with lower sensitivity (78% versus 91%) and specificity (76% versus 94%). Therefore, adipokine patterns may currently not be clinically useful for the diagnosis of metabolic diseases. Whether adipokine patterns are relevant for the predictive assessment of intervention outcomes needs to be further investigated. In obesity, elevated fat mass and ectopic fat accumulation are associated with changes in adipokine secretion, which may link obesity to inflammation and the development of insulin resistance. However, relationships among individual adipokines and between adipokines and parameters of obesity, glucose metabolism or inflammation are largely unknown. Serum concentrations of 20 adipokines were measured in 141 Caucasian obese men (n = 67) and women (n = 74) with a wide range of body weight, glycemia and insulin sensitivity. Unbiased, distance-based hierarchical cluster analyses were performed to recognize patterns among adipokines and their relationship with parameters of obesity, glucose metabolism, insulin sensitivity and inflammation. We identified two major adipokine clusters related to either (1) body fat mass and inflammation (leptin, ANGPTL3, DLL1, chemerin, Nampt, resistin) or insulin sensitivity/hyperglycemia, and lipid metabolism (vaspin, clusterin, glypican 4, progranulin, ANGPTL6, GPX3, RBP4, DLK1, SFRP5, BMP7, adiponectin, CTRP3 and 5, omentin). In addition, we found distinct adipokine clusters in subgroups of patients with or without type 2 diabetes (T2D). Logistic regression analyses revealed ANGPTL6, DLK1, Nampt and progranulin as strongest adipokine correlates of T2D in obese individuals. The panel of 20 adipokines predicted T2D compared to a combination of HbA1c, HOMA-IR and fasting plasma glucose with lower sensitivity (78% versus 91%) and specificity (76% versus 94%). Therefore, adipokine patterns may currently not be clinically useful for the diagnosis of metabolic diseases. Whether adipokine patterns are relevant for the predictive assessment of intervention outcomes needs to be further investigated.

Authors: Gesine Flehmig, Markus Scholz, Nora Klöting, Mathias Fasshauer, Anke Tönjes, Michael Stumvoll, Byung-Soo Youn, Matthias Blüher, Cedric Moro

Date Published: 26th Jun 2014

Publication Type: Journal article

Impact of age on the efficacy of bone marrow mononuclear cell transplantation in experimental stroke
Genetical Statistics and Systems Biology

Abstract (Expand)

Bone marrow-derived mononuclear cells (BM MNC) have been effectively used to treat experimental stroke. Most of the preclinical trials have been performed in young and healthy laboratory animals, even … though age and hypertension are major risk factors for stroke. To determine the influence of age on the properties of BM MNCs after cerebral ischemia, we compared the efficacy of aged and young BM MNC in an in vitro model of cerebral hypoxia and in an adapted in vivo model of stroke. Human BM MNCs were obtained from healthy young or aged donors and either co-cultured with rat hippocampal slices exposed to oxygen glucose deprivation (OGD), or transplanted intravenously 24 h after permanent middle cerebral artery occlusion in aged (18 months) spontaneously hypertensive rats (SHR). Efficacy was examined by quantification of hippocampal cell death, or respectively, by neurofunctional tests and MR investigations. Co-cultivation with young, but not with aged BM MNCs significantly reduced the hippocampal cell death after OGD. Transplantation of both young and old BM MNCs did not reduce functional deficits or ischemic lesion volume after stroke in aged SHR. These results suggest a significant impact of age on the therapeutic efficacy of BM MNCs after cerebral ischemia.

Authors: Daniel-Christoph Wagner, Mitja Bojko, Myriam Peters, Marlene Lorenz, Cornelia Voigt, Alexander Kaminski, Dirk Hasenclever, Markus Scholz, Alexander Kranz, Gesa Weise, Johannes Boltze

Date Published: 1st Dec 2012

Publication Type: Journal article

Impact of chess training on mathematics performance and concentration ability of children with learning disabilities
Genetical Statistics and Systems Biology

Abstract

Not specified

Authors: Markus Scholz, Harald Niesch, Olaf Steffen, Baerbel Ernst, Markus Loeffler, Evelin Witruk, Hans Schwarz

Date Published: 2008

Publication Type: Journal article

Impact of first- and second-line treatment for Hodgkin’s lymphoma on the incidence of AML/MDS and NHL–experience of the German Hodgkin’s Lymphoma Study Group analyzed by a parametric model of carcinogenesis
Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND\backslashr\backslashnUsing a parametric carcinogenesis model, we disentangle the superimposing effects of primary and relapse therapies of Hodgkin’s disease on secondary … neoplasias.\backslashr\backslashnPATIENTS AND METHODS\backslashr\backslashnWe analyze eight randomized trials of the German Hodgkin’s lymphoma study group [5357 individuals, 67 secondary acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) and 97 secondary non-Hodgkin’s lymphoma (NHL)]. Primary therapies were divided into four groups: radiotherapy alone, moderately dosed COPP/ABVD-like chemotherapies for intermediate and advanced stages and BEACOPP escalated.\backslashr\backslashnRESULTS\backslashr\backslashnFor secondary AML/MDS, the hazards after primary therapies are proportional (maximum at 3.4 years), while the hazard after relapse therapy is more peaked (maximum at 1.8 years). Intermediate and advanced stage chemotherapy resulted in a cumulative risk of 1.5%, while the risk after BEACOPP escalated is higher (4.4%, P = 0.004) and comparable with that after relapse therapy (4.5%). For secondary NHL, there are no differences in cumulative risk between the primary therapies (2.9%), while the risk after relapse therapy is increased (6.6%, P = 0.002).\backslashr\backslashnCONCLUSIONS\backslashr\backslashnBEACOPP escalated moderately increases the risk of secondary AML/MDS but not NHL. No differences were found between other chemotherapies of advanced stages and intermediate stages. Secondary AML/MDS occurs faster after relapse treatment than after primary treatment.

Authors: Markus Scholz, A. Engert, J. Franklin, A. Josting, V. Diehl, Dirk Hasenclever, Markus Loeffler

Date Published: 1st Mar 2011

Publication Type: Journal article

Impact of genetic similarity on imputation accuracy.
LIFE - Leipzig Research Center for Civilization Diseases, Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND: Genotype imputation is a common technique in genetic research. Genetic similarity between target population and reference dataset is crucial for high-quality results. Although several … reference panels are available, it is often not clear which is the most optimal for a particular target dataset to be imputed. Maximizing genetic similarity between study sample and intended reference panels may be the straight forward method for selecting the genetically best-matched reference. However, the impact of genetic similarity on imputation accuracy has not yet been studied in detail. RESULTS: We performed a simulation study in 20 ethnic groups obtained from POPRES. High-quality SNPs were masked and re-imputed with MaCH, MaCH-minimac and IMPUTE2 using four different HapMap reference panels (CEU, CHB-JPT, MEX and YRI). Imputation accuracy was assessed by different statistics. Genetic similarity between ethnic groups and reference populations were measured by F -statistics (F(ST)) originally proposed by Wright and G -statistics (G(ST)) introduced by Nei and others. To assess the predictive power of these measures regarding imputation accuracy, we analysed relations between them and corresponding imputation accuracy scores. We found that population genetic distances between homogeneous reference and target populations were strongly linearly correlated with resulting imputation accuracies irrespective of considered distance measure, imputation accuracy measure, missingness and imputation software used. Possible exception was African population. CONCLUSION: Usage of G(ST) or F(ST)-related measures for predicting the optimal reference panel for imputation frameworks relying on a specific reference is highly recommended. A cut-off of G(ST) < 0.01 is recommended to achieve good imputation results for high-frequency variants and small data sets. The linear relationship is less pronounced for low-frequency variants for which we also observed a dependence of imputation accuracy on the number of polymorphic sites in the reference. We also show that the software specific measures MaCH-Rsq and IMPUTE-info must be interpreted with caution if the genetic distance of target and reference population is high.

Authors: N. R. Roshyara, M. Scholz

Date Published: 22nd Jul 2015

Publication Type: Not specified

Impact of indication-shift of primary and adjuvant chemo radiation in advanced laryngeal and hypopharyngeal squamous cell carcinoma.
Genetical Statistics and Systems Biology

Abstract (Expand)

Based on level I evidence, postoperative platinum-based radiochemotherapy (PORCT) is the recommended standard of care in defined risk situations after resection of squamous cell carcinomas of the larynx … and hypopharynx (LHSCC). The value of the addition of chemotherapy to adjuvant radiation in intermediate and high risk situations other than extracapsular spread or R1-/R2 resection is still debated. From 1993 to 2009, 555 patients (median follow-up: 24.4 months) with advanced LHSCC (UICC stages III-IVB) were treated in a curative intent. Patient data were continuously documented in the county of Leipzig cancer registry and were retrospectively analyzed as mono institutional survey. PORCT was introduced into the standard procedures in 2004, but also applied before in selected cases. Based on this paradigm shift, the patient population was divided into two comparative groups treated before and after 2004. 361 patients were treated before 2004. 43.8 % received primary surgery (OP) + postoperative radiotherapy (PORT) and 20.2 % OP + PORCT. 194 patients were treated after 2004: 21.1 % received OP + PORT and 35.6 % OP + PORCT. Regarding the PORCT groups, 20.6 % received cisplatin plus 5FU before 2004 which shifted to 59.4 % after 2004. The 3-year tumor-specific-survival rate of the whole cohort was improved from 47 to 60 % (p = 0.006). The subgroup treated with OP + PORT or PORCT improved from 56.1 to 68.5 % (p = 0.028). Localization proved to be a significant and independent factor. Only patients with advanced laryngeal cancer had significant improved survival (p < 0.01), while the improvement for hypopharyngeal cancer patients was not significant (p < 0.2). After 2004, there was a slight increase (+10.2 %) of primary radiochemotherapy (pRCT) due to stronger selection if R0 > 5 mm-resectability is unlikely. Standardised use of PORCT and pRCT considering clear indications showed to be significantly involved in improved survival in advanced LHSCC.

Authors: A. Boehm, F. Lindner, G. Wichmann, U. Bauer, C. Wittekind, M. Knoedler, F. Lordick, S. Dietzsch, M. Scholz, R. Kortmann, A. Dietz

Date Published: 26th Jun 2014

Publication Type: Journal article

Impact of molecular screening for point mutations and rearrangements in routine air-dried fine-needle aspiration samples of thyroid nodules
Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND\backslashr\backslashnThe diagnostic limitations of thyroid fine-needle aspiration (FNA), such as the indeterminate category, can be partially overcome by molecular analyses. However, until … now, rearrangements have only been detected in fresh FNA material and the number of follicular thyroid carcinomas (FTCs) was rather low in previous studies. We aimed at investigating the impact of point mutations and rearrangement detection in a set of routine air-dried FNA smears with a higher percentage of FTCs.\backslashr\backslashnMETHODS\backslashr\backslashnRNA and DNA was extracted from 310 FNAs (164 indeterminate, 57 malignant, 89 benign) and corresponding formalin-fixed paraffin-embedded tissue (156 follicular adenomas [FAs], 32 FTCs, 44 papillary thyroid carcinomas [PTCs], 9 follicular variant PTCs, and 69 goiters). PAX8/PPARG and RET/PTC rearrangements were detected by qPCR, BRAF and RAS mutations by high-resolution melting PCR and by pyrosequencing.\backslashr\backslashnRESULTS\backslashr\backslashnForty-seven mutations were detected in the FNAs: 22 BRAF, 13 NRAS, and 3 HRAS mutations, 8 PAX8/PPARG, and one RET/PTC-rearrangement. While the presence of a BRAF and RET/PTC mutation was associated with cancer in 100% of samples each, the presence of a RAS and PAX8/PPARG mutation was associated with cancer in only 12% and 50% of samples, respectively. In the indeterminate group 4 of 25 carcinomas were identified by molecular FNA screening, which increased the sensitivity from 67% (cytology alone) to 75% (cytology plus molecular screening).\backslashr\backslashnCONCLUSION\backslashr\backslashnMolecular screening for point mutations and rearrangements is feasible in air-dried FNAs. Although the impact of detecting point mutations and rearrangements in FNAs has most likely been overestimated in previous studies, molecular FNA analyses improve presurgical diagnostics. The detection of BRAF mutations in FNA may improve the choice of surgery and postsurgical treatment. Further data are necessary to elucidate the true impact of detecting RAS and PAX8/PPARG mutations in FNAs. The inclusion of additional rare somatic mutations and miRNA markers might further improve the impact of molecular FNA diagnostics. BACKGROUND The diagnostic limitations of thyroid fine-needle aspiration (FNA), such as the indeterminate category, can be partially overcome by molecular analyses. However, until now, rearrangements have only been detected in fresh FNA material and the number of follicular thyroid carcinomas (FTCs) was rather low in previous studies. We aimed at investigating the impact of point mutations and rearrangement detection in a set of routine air-dried FNA smears with a higher percentage of FTCs. METHODS RNA and DNA was extracted from 310 FNAs (164 indeterminate, 57 malignant, 89 benign) and corresponding formalin-fixed paraffin-embedded tissue (156 follicular adenomas [FAs], 32 FTCs, 44 papillary thyroid carcinomas [PTCs], 9 follicular variant PTCs, and 69 goiters). PAX8/PPARG and RET/PTC rearrangements were detected by qPCR, BRAF and RAS mutations by high-resolution melting PCR and by pyrosequencing. RESULTS Forty-seven mutations were detected in the FNAs: 22 BRAF, 13 NRAS, and 3 HRAS mutations, 8 PAX8/PPARG, and one RET/PTC-rearrangement. While the presence of a BRAF and RET/PTC mutation was associated with cancer in 100% of samples each, the presence of a RAS and PAX8/PPARG mutation was associated with cancer in only 12% and 50% of samples, respectively. In the indeterminate group 4 of 25 carcinomas were identified by molecular FNA screening, which increased the sensitivity from 67% (cytology alone) to 75% (cytology plus molecular screening). CONCLUSION Molecular screening for point mutations and rearrangements is feasible in air-dried FNAs. Although the impact of detecting point mutations and rearrangements in FNAs has most likely been overestimated in previous studies, molecular FNA analyses improve presurgical diagnostics. The detection of BRAF mutations in FNA may improve the choice of surgery and postsurgical treatment. Further data are necessary to elucidate the true impact of detecting RAS and PAX8/PPARG mutations in FNAs. The inclusion of additional rare somatic mutations and miRNA markers might further improve the impact of molecular FNA diagnostics.

Authors: Markus Eszlinger, Annelise Krogdahl, Sina Münz, Christian Rehfeld, Eva Magrethe Precht Jensen, Carolina Ferraz, Eileen Bösenberg, Norbert Drieschner, Markus Scholz, Laszlo Hegedüs, Ralf Paschke

Date Published: 1st Feb 2014

Publication Type: Journal article

Impact of pre-imputation SNP-filtering on genotype imputation results
Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND Imputation of partially missing or unobserved genotypes is an indispensable tool for SNP data analyses. However, research and understanding of the impact of initial SNP-data quality control …l on imputation results is still limited. In this paper, we aim to evaluate the effect of different strategies of pre-imputation quality filtering on the performance of the widely used imputation algorithms MaCH and IMPUTE. RESULTS We considered three scenarios: imputation of partially missing genotypes with usage of an external reference panel, without usage of an external reference panel, as well as imputation of completely un-typed SNPs using an external reference panel. We first created various datasets applying different SNP quality filters and masking certain percentages of randomly selected high-quality SNPs. We imputed these SNPs and compared the results between the different filtering scenarios by using established and newly proposed measures of imputation quality. While the established measures assess certainty of imputation results, our newly proposed measures focus on the agreement with true genotypes. These measures showed that pre-imputation SNP-filtering might be detrimental regarding imputation quality. Moreover, the strongest drivers of imputation quality were in general the burden of missingness and the number of SNPs used for imputation. We also found that using a reference panel always improves imputation quality of partially missing genotypes. MaCH performed slightly better than IMPUTE2 in most of our scenarios. Again, these results were more pronounced when using our newly defined measures of imputation quality. CONCLUSION Even a moderate filtering has a detrimental effect on the imputation quality. Therefore little or no SNP filtering prior to imputation appears to be the best strategy for imputing small to moderately sized datasets. Our results also showed that for these datasets, MaCH performs slightly better than IMPUTE2 in most scenarios at the cost of increased computing time.

Authors: Nab Raj Roshyara, Holger Kirsten, Katrin Horn, Peter Ahnert, Markus Scholz

Date Published: 1st Dec 2014

Publication Type: Journal article

Increased CD64 expression on polymorphonuclear neutrophils indicates infectious complications following solid organ transplantation
Genetical Statistics and Systems Biology

Abstract (Expand)

The aim of this study was to evaluate the diagnostic value of monitoring CD64 antigen upregulation on polymorphonuclear neutrophils (PMN) for the identification of infectious complications in the … postoperative course of solid organ transplanted patients. Twenty-five kidney, 13 liver, and four pancreas-kidney transplanted patients were included. Beginning with preoperative values up to postoperative values after 3 months for each patient, the PMN CD64 Index, HLA-DR on monocytes, NKp44+ NK and NK/T cells, CXCR3+ NK cells, CXCR3+ T helper cells, CXCR3+ NK/T cells, and CD4/CD8 ratio were measured by flow cytometry. Subsequently they were correlated with confirmed postoperative complications. Measuring the PMN CD64 Index reached a sensitivity of 89% and a specificity of 65% in the detection of infectious complications. Concerning this matter, it was a significantly better marker than all other included parameters except CXCR3+ NK/T cells. In contrast, according to our results the PMN CD64 Index has no diagnostic relevance in detection of rejections. The combination of included parameters showed no improved diagnostic value. Due to its high sensitivity and specificity for infectious complications CD64 on PMN could be proven a very good indicator in evaluating suspected infectious complications in the postoperative course of transplanted patients. The aim of this study was to evaluate the diagnostic value of monitoring CD64 antigen upregulation on polymorphonuclear neutrophils (PMN) for the identification of infectious complications in the postoperative course of solid organ transplanted patients. Twenty-five kidney, 13 liver, and four pancreas-kidney transplanted patients were included. Beginning with preoperative values up to postoperative values after 3 months for each patient, the PMN CD64 Index, HLA-DR on monocytes, NKp44+ NK and NK/T cells, CXCR3+ NK cells, CXCR3+ T helper cells, CXCR3+ NK/T cells, and CD4/CD8 ratio were measured by flow cytometry. Subsequently they were correlated with confirmed postoperative complications. Measuring the PMN CD64 Index reached a sensitivity of 89% and a specificity of 65% in the detection of infectious complications. Concerning this matter, it was a significantly better marker than all other included parameters except CXCR3+ NK/T cells. In contrast, according to our results the PMN CD64 Index has no diagnostic relevance in detection of rejections. The combination of included parameters showed no improved diagnostic value. Due to its high sensitivity and specificity for infectious complications CD64 on PMN could be proven a very good indicator in evaluating suspected infectious complications in the postoperative course of transplanted patients.

Authors: Daniel Grey, Ulrich Sack, Markus Scholz, Heike Knaack, Stephan Fricke, Christoph Oppel, Daniel Luderer, Josef Fangmann, Frank Emmrich, Manja Kamprad

Date Published: 1st Jun 2011

Publication Type: Journal article

Independent Risk Factors for Fast-Track Failure Using a Predefined Fast-Track Protocol in Preselected Cardiac Surgery Patients
Genetical Statistics and Systems Biology

Abstract (Expand)

OBJECTISVES The purpose of this study was to identify the independent risk factors for fast-track failure (FTF) in cardiac surgery patients. DESIGN A retrospective analysis. SETTING A university-affiliated …iated heart center. PARTICIPANTS In a 2-year period, 1,704 consecutive preselected patients undergoing elective cardiac surgery were treated according to the local fast-track protocol in the postanesthetic care unit (PACU), bypassing the intensive care unit (ICU). MEASUREMENTS AND RESULTS Independent risk factors for FTF in the univariate regression analysis were tested in a multivariate regression analysis. FTF was defined as any transfer of the preselected patient to the ICU. FTF was primary when the patient was transferred directly from the postanesthetic care unit to the ICU and secondary when the patient was transferred from the intermediate care unit or ward to the ICU. FTF rate was 11.6% for primary and 5.6% for secondary FTF. In the multivariate regression analysis, age\textgreater70 years, female sex, prolonged surgery, and prolonged cross-clamp time could be defined as independent risk factors for FTF. CONCLUSIONS In a preselected patient population, fast-track treatment could be done with a low FTF rate. Independent risk factors for FTF are age, female sex, prolonged surgery, and prolonged cross-clamp time.

Authors: Zakhary Waseem, Jacob Lindner, Sophia Sgouropoulou, Sarah Eibel, Stefan Probst, Markus Scholz, Joerg Ender

Date Published: 1st Dec 2015

Publication Type: Journal article

Indications for potential parent-of-origin effects within the FTO gene
Genetical Statistics and Systems Biology

Abstract (Expand)

Genome-Wide Association Studies (GWAS) were successfully applied to discover associations with obesity. However, the GWAS design is usually based on unrelated individuals and inheritance information … on the parental origin of the alleles is missing. Taking into account parent-of-origin may provide further insights into the genetic mechanisms contributing to obesity. We hypothesized that there may be variants within the robustly replicated fat mass and obesity associated (FTO) gene that may confer different risk for obesity depending on transmission from mother or father. Genome-wide genotypes and pedigree information from the Sorbs population were used. Phased genotypes among 525 individuals were generated by AlphaImpute. Subsequently, 22 SNPs within FTO introns 1 to 3 were selected and parent-of-origin specific association analyses were performed using PLINK. Interestingly, we identified several SNPs conferring different genetic effects (P\leq0.05) depending on parental origin-among them, rs1861868, rs1121980 and rs9939973 (all in intron 1). To confirm our findings, we investigated the selected variants in 705 German trios comprising an (extremely) obese child or adolescent and both parents. Again, we observed evidence for POE effects in intron 2 and 3 (P\leq0.05) as indicated by the parental asymmetry test. Our results suggest that the obesity risk transmitted by several FTO variants may depend on the parental origin of the allele. Larger family-based studies are warranted to replicate our findings.   Genome-Wide Association Studies (GWAS) were successfully applied to discover associations with obesity. However, the GWAS design is usually based on unrelated individuals and inheritance information on the parental origin of the alleles is missing. Taking into account parent-of-origin may provide further insights into the genetic mechanisms contributing to obesity. We hypothesized that there may be variants within the robustly replicated fat mass and obesity associated (FTO) gene that may confer different risk for obesity depending on transmission from mother or father. Genome-wide genotypes and pedigree information from the Sorbs population were used. Phased genotypes among 525 individuals were generated by AlphaImpute. Subsequently, 22 SNPs within FTO introns 1 to 3 were selected and parent-of-origin specific association analyses were performed using PLINK. Interestingly, we identified several SNPs conferring different genetic effects (P\leq0.05) depending on parental origin–among them, rs1861868, rs1121980 and rs9939973 (all in intron 1). To confirm our findings, we investigated the selected variants in 705 German trios comprising an (extremely) obese child or adolescent and both parents. Again, we observed evidence for POE effects in intron 2 and 3 (P\leq0.05) as indicated by the parental asymmetry test. Our results suggest that the obesity risk transmitted by several FTO variants may depend on the parental origin of the allele. Larger family-based studies are warranted to replicate our findings. //  Genome-Wide Association Studies (GWAS) were successfully applied to discover associations with obesity. However, the GWAS design is usually based on unrelated individuals and inheritance information on the parental origin of the alleles is missing. Taking into account parent-of-origin may provide further insights into the genetic mechanisms contributing to obesity. We hypothesized that there may be variants within the robustly replicated fat mass and obesity associated (FTO) gene that may confer different risk for obesity depending on transmission from mother or father. Genome-wide genotypes and pedigree information from the Sorbs population were used. Phased genotypes among 525 individuals were generated by AlphaImpute. Subsequently, 22 SNPs within FTO introns 1 to 3 were selected and parent-of-origin specific association analyses were performed using PLINK. Interestingly, we identified several SNPs conferring different genetic effects (P\leq0.05) depending on parental origin–among them, rs1861868, rs1121980 and rs9939973 (all in intron 1). To confirm our findings, we investigated the selected variants in 705 German trios comprising an (extremely) obese child or adolescent and both parents. Again, we observed evidence for POE effects in intron 2 and 3 (P\leq0.05) as indicated by the parental asymmetry test. Our results suggest that the obesity risk transmitted by several FTO variants may depend on the parental origin of the allele. Larger family-based studies are warranted to replicate our findings.

Authors: Xuanshi Liu, Anke Hinney, Markus Scholz, André Scherag, Anke Tönjes, Michael Stumvoll, Peter F. Stadler, Johannes Hebebrand, Yvonne Böttcher

Date Published: 20th Mar 2015

Publication Type: Journal article

Influence of low dose irradiation on differentiation, maturation and T-cell activation of human dendritic cells
Genetical Statistics and Systems Biology

Abstract (Expand)

Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both … the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment. There was no difference of single dose irradiation versus fractionated irradiation protocols on the behavior of the mature DCs. Further, the low dose irradiation did not change the capacity of the DCs to stimulate T-cell proliferation. But the irradiation of the co-culture of DCs and T-cells revealed significantly lower proliferation of T-cells with higher doses. Summarizing the data from approx. 50 DC preparations there is no significant effect of low dose ionizing irradiation on the cytokine profile, surface marker expression and maturation of DCs in vitro although functional consequences cannot be excluded. Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment. There was no difference of single dose irradiation versus fractionated irradiation protocols on the behavior of the mature DCs. Further, the low dose irradiation did not change the capacity of the DCs to stimulate T-cell proliferation. But the irradiation of the co-culture of DCs and T-cells revealed significantly lower proliferation of T-cells with higher doses. Summarizing the data from approx. 50 DC preparations there is no significant effect of low dose ionizing irradiation on the cytokine profile, surface marker expression and maturation of DCs in vitro although functional consequences cannot be excluded.

Authors: Jutta Jahns, Ulf Anderegg, Anja Saalbach, Britt Rosin, Ina Patties, Annegret Glasow, Manja Kamprad, Markus Scholz, Guido Hildebrandt

Date Published: 1st May 2011

Publication Type: Journal article

Integration of Genome-Wide SNP Data and Gene-Expression Profiles Reveals Six Novel Loci and Regulatory Mechanisms for Amino Acids and Acylcarnitines in Whole Blood.
Genetical Statistics and Systems Biology

Abstract (Expand)

Profiling amino acids and acylcarnitines in whole blood spots is a powerful tool in the laboratory diagnosis of several inborn errors of metabolism. Emerging data suggests that altered blood levels of … amino acids and acylcarnitines are also associated with common metabolic diseases in adults. Thus, the identification of common genetic determinants for blood metabolites might shed light on pathways contributing to human physiology and common diseases. We applied a targeted mass-spectrometry-based method to analyze whole blood concentrations of 96 amino acids, acylcarnitines and pathway associated metabolite ratios in a Central European cohort of 2,107 adults and performed genome-wide association (GWA) to identify genetic modifiers of metabolite concentrations. We discovered and replicated six novel loci associated with blood levels of total acylcarnitine, arginine (both on chromosome 6; rs12210538, rs17657775), propionylcarnitine (chromosome 10; rs12779637), 2-hydroxyisovalerylcarnitine (chromosome 21; rs1571700), stearoylcarnitine (chromosome 1; rs3811444), and aspartic acid traits (chromosome 8; rs750472). Based on an integrative analysis of expression quantitative trait loci in blood mononuclear cells and correlations between gene expressions and metabolite levels, we provide evidence for putative causative genes: SLC22A16 for total acylcarnitines, ARG1 for arginine, HLCS for 2-hydroxyisovalerylcarnitine, JAM3 for stearoylcarnitine via a trans-effect at chromosome 1, and PPP1R16A for aspartic acid traits. Further, we report replication and provide additional functional evidence for ten loci that have previously been published for metabolites measured in plasma, serum or urine. In conclusion, our integrative analysis of SNP, gene-expression and metabolite data points to novel genetic factors that may be involved in the regulation of human metabolism. At several loci, we provide evidence for metabolite regulation via gene-expression and observed overlaps with GWAS loci for common diseases. These results form a strong rationale for subsequent functional and disease-related studies.

Authors: R. Burkhardt, H. Kirsten, F. Beutner, L. M. Holdt, A. Gross, A. Teren, A. Tonjes, S. Becker, K. Krohn, P. Kovacs, M. Stumvoll, D. Teupser, J. Thiery, U. Ceglarek, M. Scholz

Date Published: 25th Sep 2015

Publication Type: Not specified

Human Diseases: kidney disease

Integration of mathematical model predictions into routine workflows to support clinical decision making in haematology
Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND Individualization and patient-specific optimization of treatment is a major goal of modern health care. One way to achieve this goal is the application of high-resolution diagnostics together …r with the application of targeted therapies. However, the rising number of different treatment modalities also induces new challenges: Whereas randomized clinical trials focus on proving average treatment effects in specific groups of patients, direct conclusions at the individual patient level are problematic. Thus, the identification of the best patient-specific treatment options remains an open question. Systems medicine, specifically mechanistic mathematical models, can substantially support individual treatment optimization. In addition to providing a better general understanding of disease mechanisms and treatment effects, these models allow for an identification of patient-specific parameterizations and, therefore, provide individualized predictions for the effect of different treatment modalities. RESULTS In the following we describe a software framework that facilitates the integration of mathematical models and computer simulations into routine clinical processes to support decision-making. This is achieved by combining standard data management and data exploration tools, with the generation and visualization of mathematical model predictions for treatment options at an individual patient level. CONCLUSIONS By integrating model results in an audit trail compatible manner into established clinical workflows, our framework has the potential to foster the use of systems-medical approaches in clinical practice. We illustrate the framework application by two use cases from the field of haematological oncology.

Authors: Katja Hoffmann, Katja Cazemier, Christoph Baldow, Silvio Schuster, Yuri Kheifetz, Sibylle Schirm, Matthias Horn, Thomas Ernst, Constanze Volgmann, Christian Thiede, Andreas Hochhaus, Martin Bornhäuser, Meinolf Suttorp, Markus Scholz, Ingmar Glauche, Markus Loeffler, Ingo Roeder

Date Published: 1st Dec 2020

Publication Type: Journal article

Intrathecal morphine is superior to intravenous PCA in patients undergoing minimally invasive cardiac surgery
Genetical Statistics and Systems Biology

Abstract (Expand)

Aim of our study was to evaluate the beneficial effect of low dose intrathecal morphine on postoperative analgesia, over the use of intravenous patient controlled anesthesia (PCA), in patients undergoing … fast track anesthesia during minimally invasive cardiac surgical procedures. A randomized controlled trial was undertaken after approval from local ethical committee. Written informed consent was obtained from 61 patients receiving mitral or tricuspid or both surgical valve repair in minimal invasive technique. Patients were assigned randomly to 2 groups. Group 1 received general anesthesia and intravenous patient controlled analgesia (PCA) pump with Piritramide (GA group). Group 2 received a single shot of intrathecal morphine (1.5 \textgreekmg/kg body weight) prior to the administration of general anesthesia (ITM group). Site of puncture was confined to lumbar (L1-2 or L2-3) intrathecal space. The amount of intravenous piritramide used in post anesthesia care unit (PACU) and the first postoperative day was defined as primary end point. Secondary end points included: time for tracheal extubation, pain and sedation scores in PACU upto third postoperative day. For statistical analysis Mann-Whitney-U Test and Fishers exact test (SPSS) were used. We found that the demand for intravenous opioids in PACU was significantly reduced in ITM group (P \textless0.001). Pain scores were significantly decreased in ITM group until second postoperative day (P \textless0.01). There was no time delay for tracheal extubation in ITM group, and sedation scores did not differ in either group. We conclude that low dose single shot intrathecal morphine provides adequate postoperative analgesia, reduces the intravenous opioid consumption during the early postoperative period and does not defer early extubation.

Authors: Chirojit Mukherjee, Eva Koch, Joergen Banusch, Markus Scholz, Udo X. Kaisers, Joerg Ender

Date Published: 2012

Publication Type: Journal article

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