Publications

227 Publications visible to you, out of a total of 227

Abstract (Expand)

OBJECTIVE\backslashr\backslashnWe established the Leipzig (LIFE) Heart Study, a biobank and database of patients with different stages of coronary artery disease (CAD) for studies of clinical, metabolic, cellular and genetic factors of cardiovascular diseases.\backslashr\backslashnDESIGN\backslashr\backslashnThe Leipzig (LIFE) Heart Study (NCT00497887) is an ongoing observational angiographic study including subjects with different entities of CAD. Cohort 1, patients undergoing first-time diagnostic coronary angiography due to suspected stable CAD with previously untreated coronary arteries. Cohort 2, patients with acute myocardial infarction (MI) requiring percutaneous revascularization. Cohort 3, patients with known left main coronary artery disease (LMCAD).\backslashr\backslashnRESULTS\backslashr\backslashnWe present preliminary results of demographics and phenotyping based on a 4-years analysis of a total of 3,165 subjects. Cohort 1 (n=2,274) shows the typical distribution of elective coronary angiography cohorts with 43% cases with obstructive CAD and 37% normal angiograms. Cohorts 2 and 3 consist of 590 and 301 subjects, respectively, adding patients with severe forms of CAD. The suitability of the database and biobank to perform association studies was confirmed by replication of the CAD susceptibility locus on chromosome 9p21 (OR per allele: 1.55 (any CAD), 1.54 (MI), 1.74 (LMCAD), p\textless10(-6), respectively). A novel finding was that patients with LMCAD had a stronger association with 9p21 than patients with obstructive CAD without LMCAD (OR 1.22, p=0.042). In contrast, 9p21 did not associate with myocardial infarction in excess of stable CAD.\backslashr\backslashnCONCLUSION\backslashr\backslashnThe Leipzig (LIFE) Heart Study provides a basis to identify molecular targets related to atherogenesis and associated metabolic disorders. The study may contribute to an improvement of individual prediction, prevention, and treatment of CAD. OBJECTIVE We established the Leipzig (LIFE) Heart Study, a biobank and database of patients with different stages of coronary artery disease (CAD) for studies of clinical, metabolic, cellular and genetic factors of cardiovascular diseases. DESIGN The Leipzig (LIFE) Heart Study (NCT00497887) is an ongoing observational angiographic study including subjects with different entities of CAD. Cohort 1, patients undergoing first-time diagnostic coronary angiography due to suspected stable CAD with previously untreated coronary arteries. Cohort 2, patients with acute myocardial infarction (MI) requiring percutaneous revascularization. Cohort 3, patients with known left main coronary artery disease (LMCAD). RESULTS We present preliminary results of demographics and phenotyping based on a 4-years analysis of a total of 3,165 subjects. Cohort 1 (n=2,274) shows the typical distribution of elective coronary angiography cohorts with 43% cases with obstructive CAD and 37% normal angiograms. Cohorts 2 and 3 consist of 590 and 301 subjects, respectively, adding patients with severe forms of CAD. The suitability of the database and biobank to perform association studies was confirmed by replication of the CAD susceptibility locus on chromosome 9p21 (OR per allele: 1.55 (any CAD), 1.54 (MI), 1.74 (LMCAD), p\textless10(-6), respectively). A novel finding was that patients with LMCAD had a stronger association with 9p21 than patients with obstructive CAD without LMCAD (OR 1.22, p=0.042). In contrast, 9p21 did not associate with myocardial infarction in excess of stable CAD. CONCLUSION The Leipzig (LIFE) Heart Study provides a basis to identify molecular targets related to atherogenesis and associated metabolic disorders. The study may contribute to an improvement of individual prediction, prevention, and treatment of CAD. OBJECTIVE We established the Leipzig (LIFE) Heart Study, a biobank and database of patients with different stages of coronary artery disease (CAD) for studies of clinical, metabolic, cellular and genetic factors of cardiovascular diseases. DESIGN The Leipzig (LIFE) Heart Study (NCT00497887) is an ongoing observational angiographic study including subjects with different entities of CAD. Cohort 1, patients undergoing first-time diagnostic coronary angiography due to suspected stable CAD with previously untreated coronary arteries. Cohort 2, patients with acute myocardial infarction (MI) requiring percutaneous revascularization. Cohort 3, patients with known left main coronary artery disease (LMCAD). RESULTS We present preliminary results of demographics and phenotyping based on a 4-years analysis of a total of 3,165 subjects. Cohort 1 (n=2,274) shows the typical distribution of elective coronary angiography cohorts with 43% cases with obstructive CAD and 37% normal angiograms. Cohorts 2 and 3 consist of 590 and 301 subjects, respectively, adding patients with severe forms of CAD. The suitability of the database and biobank to perform association studies was confirmed by replication of the CAD susceptibility locus on chromosome 9p21 (OR per allele: 1.55 (any CAD), 1.54 (MI), 1.74 (LMCAD), p\textless10(-6), respectively). A novel finding was that patients with LMCAD had a stronger association with 9p21 than patients with obstructive CAD without LMCAD (OR 1.22, p=0.042). In contrast, 9p21 did not associate with myocardial infarction in excess of stable CAD. CONCLUSION The Leipzig (LIFE) Heart Study provides a basis to identify molecular targets related to atherogenesis and associated metabolic disorders. The study may contribute to an improvement of individual prediction, prevention, and treatment of CAD. OBJECTIVE We established the Leipzig (LIFE) Heart Study, a biobank and database of patients with different stages of coronary artery disease (CAD) for studies of clinical, metabolic, cellular and genetic factors of cardiovascular diseases. DESIGN The Leipzig (LIFE) Heart Study (NCT00497887) is an ongoing observational angiographic study including subjects with different entities of CAD. Cohort 1, patients undergoing first-time diagnostic coronary angiography due to suspected stable CAD with previously untreated coronary arteries. Cohort 2, patients with acute myocardial infarction (MI) requiring percutaneous revascularization. Cohort 3, patients with known left main coronary artery disease (LMCAD). RESULTS We present preliminary results of demographics and phenotyping based on a 4-years analysis of a total of 3,165 subjects. Cohort 1 (n=2,274) shows the typical distribution of elective coronary angiography cohorts with 43% cases with obstructive CAD and 37% normal angiograms. Cohorts 2 and 3 consist of 590 and 301 subjects, respectively, adding patients with severe forms of CAD. The suitability of the database and biobank to perform association studies was confirmed by replication of the CAD susceptibility locus on chromosome 9p21 (OR per allele: 1.55 (any CAD), 1.54 (MI), 1.74 (LMCAD), p\textless10(-6), respectively). A novel finding was that patients with LMCAD had a stronger association with 9p21 than patients with obstructive CAD without LMCAD (OR 1.22, p=0.042). In contrast, 9p21 did not associate with myocardial infarction in excess of stable CAD. CONCLUSION The Leipzig (LIFE) Heart Study provides a basis to identify molecular targets related to atherogenesis and associated metabolic disorders. The study may contribute to an improvement of individual prediction, prevention, and treatment of CAD. OBJECTIVE We established the Leipzig (LIFE) Heart Study, a biobank and database of patients with different stages of coronary artery disease (CAD) for studies of clinical, metabolic, cellular and genetic factors of cardiovascular diseases. DESIGN The Leipzig (LIFE) Heart Study (NCT00497887) is an ongoing observational angiographic study including subjects with different entities of CAD. Cohort 1, patients undergoing first-time diagnostic coronary angiography due to suspected stable CAD with previously untreated coronary arteries. Cohort 2, patients with acute myocardial infarction (MI) requiring percutaneous revascularization. Cohort 3, patients with known left main coronary artery disease (LMCAD). RESULTS We present preliminary results of demographics and phenotyping based on a 4-years analysis of a total of 3,165 subjects. Cohort 1 (n=2,274) shows the typical distribution of elective coronary angiography cohorts with 43% cases with obstructive CAD and 37% normal angiograms. Cohorts 2 and 3 consist of 590 and 301 subjects, respectively, adding patients with severe forms of CAD. The suitability of the database and biobank to perform association studies was confirmed by replication of the CAD susceptibility locus on chromosome 9p21 (OR per allele: 1.55 (any CAD), 1.54 (MI), 1.74 (LMCAD), p\textless10(-6), respectively). A novel finding was that patients with LMCAD had a stronger association with 9p21 than patients with obstructive CAD without LMCAD (OR 1.22, p=0.042). In contrast, 9p21 did not associate with myocardial infarction in excess of stable CAD. CONCLUSION The Leipzig (LIFE) Heart Study provides a basis to identify molecular targets related to atherogenesis and associated metabolic disorders. The study may contribute to an improvement of individual prediction, prevention, and treatment of CAD.

Authors: Frank Beutner, Daniel Teupser, Stephan Gielen, Lesca Miriam Holdt, Markus Scholz, Enno Boudriot, Gerhard Schuler, Joachim Thiery, Massimo Federici

Date Published: 22nd Dec 2011

Publication Type: Journal article

Abstract (Expand)

Rare causal variants are believed to significantly contribute to the genetic basis of common diseases or quantitative traits. Appropriate statistical methods are required to discover the highest possible number of disease-relevant variants in a genome-wide screening study. The publicly available Genetic Analysis Workshop 17 data set consists of 697 individuals and 24,487 genetic variants. It includes a simulated complex disease model with intermediate quantitative phenotypes. We compare four gene-wise scoring methods with respect to ranking of causal genes under variable allele frequency thresholds for collapsing of rare variants and considering whether or not rare variants were included. We also compare causal genes for which the ranks differ clearly between scoring methods regarding such characteristics as number and strength of causal variants. We corroborated our findings with additional simulations. We found that the maximum statistics method was superior in assigning high ranks to genes with a single strong causal variant. Hotelling’s T2 test was superior for genes with several independent causal variants. This was consistent for all phenotypes and was confirmed by single-gene analyses and additional simulations. The multivariate analysis performed similarly to Hotelling’s T2 test. The least absolute shrinkage and selection operator (LASSO) analysis was widely comparable with the maximum statistics method. We conclude that the maximum statistics method is a superior alternative to Hotelling’s T2 test if one expects only one independent causal variant per gene with a dominating effect. Such a variant could also be a supermarker derived by collapsing rare variants. Because the true nature of the genetic effect is unknown for real data, both methods need to be taken into consideration.

Authors: Markus Scholz, Holger Kirsten

Date Published: 1st Dec 2011

Publication Type: Journal article

Abstract (Expand)

Meningiomas are classified as benign, atypical, or anaplastic. The majority are sporadic, solitary, and benign tumors with favorable prognoses. However, the prognosis for patients with anaplastic meningiomas remains less favorable. High resolution genomic profiling has the capacity to provide more detailed information. Therefore, we analyzed genomic aberrations of benign and atypical meningiomas using single nucleotide polymorphism (SNP) array, combined with G-banding by trypsin using Giemsa stain (GTG banding), spectral karyotyping, and locus-specific fluorescence in situ hybridization (FISH). We confirmed frequently detected chromosomal aberrations in meningiomas and identified novel genetic events. Applying SNP array, we identified constitutional de novo loss or gain within chromosome 22 in three patients, possibly representing inherited causal events for meningioma formation. We show evidence for somatic segmental uniparental disomy in regions 4p16.1, 7q31.2, 8p23.2, and 9p22.1 not previously described for primary meningioma. GTG-banding and spectral karyotyping detected a novel balanced reciprocal translocation t(4;10)(q12;q26) in one benign meningioma. A paracentric inversion within 1p36, previously described as novel, was detected as a recurrent chromosomal aberration in benign and atypical meningiomas. Analyses of tumors and matched normal tissues with a combination of SNP arrays and complementary techniques will help to further elucidate potentially causal genetic events for tumorigenesis of meningioma.

Authors: Heidrun Holland, Kristin Mocker, Peter Ahnert, Holger Kirsten, Helene Hantmann, Ronald Koschny, Manfred Bauer, Ralf Schober, Markus Scholz, Jürgen Meixensberger, Wolfgang Krupp

Date Published: 1st Oct 2011

Publication Type: Journal article

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Population isolates have long been of interest to genetic epidemiologists because of their potential to increase power to detect disease-causing genetic variants. The Sorbs of Germany are considered as cultural and linguistic isolates and have recently been the focus of disease association mapping efforts. They are thought to have settled in their present location in eastern Germany after a westward migration from a largely Slavic-speaking territory during the Middle Ages. To examine Sorbian genetic diversity within the context of other European populations, we analyzed genotype data for over 30 000 autosomal single-nucleotide polymorphisms from over 200 Sorbs individuals. We compare the Sorbs with other European individuals, including samples from population isolates. Despite their geographical proximity to German speakers, the Sorbs showed greatest genetic similarity to Polish and Czech individuals, consistent with the linguistic proximity of Sorbian to other West Slavic languages. The Sorbs also showed evidence of subtle levels of genetic isolation in comparison with samples from non-isolated European populations. The level of genetic isolation was less than that observed for the Sardinians and French Basque, who were clear outliers on multiple measures of isolation. The finding of the Sorbs as only a minor genetic isolate demonstrates the need to genetically characterize putative population isolates, as they possess a wide range of levels of isolation because of their different demographic histories.

Authors: Krishna R. Veeramah, Anke Tönjes, Peter Kovacs, Arnd Gross, Daniel Wegmann, Patrick Geary, Daniela Gasperikova, Iwar Klimes, Markus Scholz, John Novembre, Michael Stumvoll

Date Published: 1st Sep 2011

Publication Type: Journal article

Abstract (Expand)

BACKGROUND\backslashr\backslashnObesity is a risk factor for atherosclerotic vascular disease. Altered adipokine secretion, including increased production of nicotinamide phosphoribosyltransferase (Nampt) and retinol binding protein 4 (RBP4) may link adipose tissue dysfunction to cardiovascular complications.\backslashr\backslashnMETHODS\backslashr\backslashnWe determined Nampt and RBP4 serum concentrations in 193 consecutive patients with carotid stenosis prior to carotid endarterectomy (CEA) in relation to recently experienced ischemic events, markers of atherosclerosis and obesity, as well as anthropometric and clinical characteristics.\backslashr\backslashnRESULTS\backslashr\backslashnNampt but not RBP4 was significantly higher in symptomatic patients who experienced an ischemic event within 6 months before surgery compared to asymptomatic patients (p=0.001). In multivariate regression analysis Nampt was the only independent predictor of symptomatic carotid stenosis. Nampt correlated with peripheral leukocyte blood count (p\textless0.0001) and with the number of macrophages/foam cells within carotid plaques (p=0.042). However, Nampt and RBP4 serum concentrations did not correlate with the maximum percentage of carotid stenosis.\backslashr\backslashnCONCLUSION\backslashr\backslashnOur data suggest circulating Nampt as an independent predictor of recently experienced ischemic events in patients with carotid stenosis despite the lack of an association between Nampt and carotid atherosclerosis severity. BACKGROUND Obesity is a risk factor for atherosclerotic vascular disease. Altered adipokine secretion, including increased production of nicotinamide phosphoribosyltransferase (Nampt) and retinol binding protein 4 (RBP4) may link adipose tissue dysfunction to cardiovascular complications. METHODS We determined Nampt and RBP4 serum concentrations in 193 consecutive patients with carotid stenosis prior to carotid endarterectomy (CEA) in relation to recently experienced ischemic events, markers of atherosclerosis and obesity, as well as anthropometric and clinical characteristics. RESULTS Nampt but not RBP4 was significantly higher in symptomatic patients who experienced an ischemic event within 6 months before surgery compared to asymptomatic patients (p=0.001). In multivariate regression analysis Nampt was the only independent predictor of symptomatic carotid stenosis. Nampt correlated with peripheral leukocyte blood count (p\textless0.0001) and with the number of macrophages/foam cells within carotid plaques (p=0.042). However, Nampt and RBP4 serum concentrations did not correlate with the maximum percentage of carotid stenosis. CONCLUSION Our data suggest circulating Nampt as an independent predictor of recently experienced ischemic events in patients with carotid stenosis despite the lack of an association between Nampt and carotid atherosclerosis severity.

Authors: Gabriela Aust, Migle Uptaite-Patapoviene, Markus Scholz, Olaf Richter, Silvio Rohm, Matthias Blüher

Date Published: 1st Jun 2011

Publication Type: Journal article

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

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The tumor entity of hemangiopericytoma is not universally recognized as a nosological entity by pathologists, and there is a trend toward reassigning it to other categories gradually. However, hemangiopericytomas occurring in the nervous system are included in the new WHO classification of brain tumors, and are distinguished from both meningioma and fibrous tumors. Since there are few genetic studies, we performed a comprehensive cytogenetic analysis of an infratentorial hemangiopericytoma in a 55-year-old female. It was originally classified as a grade II tumor but recurred as a grade III tumor with a proliferation index of 20%. Using trypsin-Giemsa staining (GTG-banding) and multicolor fluorescence in situ hybridization (M-FISH), we could confirm the loss of chromosomal material 10q, which has been previously described in hemangiopericytoma, and we identified de novo chromosomal aberrations on chromosome 8. Applying genome-wide high-density single nucleotide polymorphism array (SNP-A) analysis, we detected segments with loss or gain, as well as clonal deletions or regions suggestive of segmental uniparental disomy. These findings, together with the results of conventional histological and immunohistochemical characterization, provide additional evidence for the nosological separation of hemangiopericytoma in the central nervous system as a biologically different entity.

Authors: Heidrun Holland, Michela Livrea, Peter Ahnert, Ronald Koschny, Holger Kirsten, Jürgen Meixensberger, Manfred Bauer, Ralf Schober, Dominik Fritzsch, Wolfgang Krupp

Date Published: 1st May 2011

Publication Type: Journal article

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