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188 Publications visible to you, out of a total of 188
A new evaluation and training system for micro-telemanipulation at the middle ear
Genetical Statistics and Systems Biology

Abstract (Expand)

In this article, a new surgical model for evaluating telemanipulators used in middle ear surgery is presented. The purpose of this work was to develop an evaluation and training system which imitates … a typical surgical task of middle ear surgery and which can easily be repeated in order to get significant result. The abstract task can be performed manually or by means of a microsurgical telemanipulator and guaranties stable experimental conditions between different subjects at any time. As a task the stapedotomy was chosen, due to the high demands in positioning and in applying forces to the delicate structures in the middle ear. The manual and telemanipulated performance of 15 ENT surgeons and 17 medical students was compared using this evaluation and training system. In this article, a new surgical model for evaluating telemanipulators used in middle ear surgery is presented. The purpose of this work was to develop an evaluation and training system which imitates a typical surgical task of middle ear surgery and which can easily be repeated in order to get significant result. The abstract task can be performed manually or by means of a microsurgical telemanipulator and guaranties stable experimental conditions between different subjects at any time. As a task the stapedotomy was chosen, due to the high demands in positioning and in applying forces to the delicate structures in the middle ear. The manual and telemanipulated performance of 15 ENT surgeons and 17 medical students was compared using this evaluation and training system.

Authors: Thomas Maier, Gero Strauss, Markus Scholz, Thomas Berger, Anne Kielhorn, Konrad Entsfellner, Christian Willim, Wolfgang Buscher, Andreas Dietz, Tim C. Lueth

Date Published: 1st Aug 2012

Publication Type: Journal article

KMWin--a convenient tool for graphical presentation of results from Kaplan-Meier survival time analysis.
GLA - German Lymphoma Alliance, Genetical Statistics and Systems Biology

Abstract (Expand)

BACKGROUND: Analysis of clinical studies often necessitates multiple graphical representations of the results. Many professional software packages are available for this purpose. Most packages are … either only commercially available or hard to use especially if one aims to generate or customize a huge number of similar graphical outputs. We developed a new, freely available software tool called KMWin (Kaplan-Meier for Windows) facilitating Kaplan-Meier survival time analysis. KMWin is based on the statistical software environment R and provides an easy to use graphical interface. Survival time data can be supplied as SPSS (sav), SAS export (xpt) or text file (dat), which is also a common export format of other applications such as Excel. Figures can directly be exported in any graphical file format supported by R. RESULTS: On the basis of a working example, we demonstrate how to use KMWin and present its main functions. We show how to control the interface, customize the graphical output, and analyse survival time data. A number of comparisons are performed between KMWin and SPSS regarding graphical output, statistical output, data management and development. Although the general functionality of SPSS is larger, KMWin comprises a number of features useful for survival time analysis in clinical trials and other applications. These are for example number of cases and number of cases under risk within the figure or provision of a queue system for repetitive analyses of updated data sets. Moreover, major adjustments of graphical settings can be performed easily on a single window. CONCLUSIONS: We conclude that our tool is well suited and convenient for repetitive analyses of survival time data. It can be used by non-statisticians and provides often used functions as well as functions which are not supplied by standard software packages. The software is routinely applied in several clinical study groups.

Authors: A. Gross, M. Ziepert, M. Scholz

Date Published: 23rd Jun 2012

Publication Type: Not specified

Combined effects of different interleukin-28B gene variants on the outcome of dual combination therapy in chronic hepatitis C virus type 1 infection
Genetical Statistics and Systems Biology

Abstract (Expand)

In patients with chronic hepatitis C virus (HCV) infection, several variants of the interleukin-28B (IL28B) gene have been shown to correlate significantly with a sustained virologic response (SVR). … Recent evidence shows that determination of one single IL28B polymorphism, rs12979860, is sufficient for predicting treatment outcome. We examined whether the combined determination of the IL28B single-nucleotide polymorphisms (SNPs), rs12979860, rs8099917, rs12980275, and rs8103142, might improve the prediction of SVR in patients with HCV. In the study cohort, 54% of 942 patients with chronic HCV type 1 infection had SVR. The IL28B SNPs, rs12979860CC and rs8099917TT, correlated significantly with SVR (68% and 62%). The SNPs, rs12980275 and rs8103142, were in strong linkage disequilibrium with rs12979860 and were not included in further analysis. In homozygous carriers of the rs12979860 responder allele C, additional genotyping of the rs8099917 SNP had no effect on response prediction, whereas in carriers of the rs12979860 nonresponder allele, the rs8099917 SNP improved the response prediction. In heterozygous carriers of the rs12979860 nonresponder T allele, SVR rates were 55% in the presence of the rs8099917TT genotype and 40% in patients carrying the rs8099917 TG or GG genotype. Analysis of an independent confirmation cohort of 377 HCV type 1-infected patients verified the significant difference in SVR rates between the combined genotypes, rs12979860CT/rs8099917TT and rs12979860CT/rs8099917TG (38% versus 21%; P = 0.018). Conclusion: Treatment outcome prediction could not be improved in homozygous carriers of the IL28B rs12979860 C responder allele by the additional determination of the rs8099917 SNP. There is evidence that a significant proportion of heterozygous carriers of the rs12979860 T nonresponder allele can profit with respect to SVR prediction by further determination of the rs8099917 SNP. (HEPATOLOGY 2012;55:1700-1710).

Authors: Janett Fischer, Stephan Böhm, Markus Scholz, Tobias Müller, Heiko Witt, Jacob George, Christoph Sarrazin, Simone Susser, Eckart Schott, Vijayaprakash Suppiah, David R. Booth, Graeme J. Stewart, Florian van Bömmel, Annika Brodzinski, Balazs Fülöp, Pascal Migaud, Thomas Berg

Date Published: 1st Jun 2012

Publication Type: Journal article

Pre-operative Tei Index does not predict left ventricular function immediately after mitral valve repair
Genetical Statistics and Systems Biology

Abstract (Expand)

Echocardiographic assessment of systolic left ventricular (LV) function in patients with severe mitral regurgitation (MR) undergoing mitral valve (MV) repair can be challenging because the measurement … of ejection fraction (EF) or fractional area change (FAC) in pathological states is of questionable value. The aim of our study was to evaluate the usefulness of the pre-operative Tei Index in predicting left ventricular EF or FAC immediately after MV repair. One hundred and thirty patients undergoing MV repair with sinus rhythm pre- and post-operatively were enrolled in this prospective study. Twenty-six patients were excluded due to absence of sinus rhythm post-operatively. Standard transesophageal examination (IE 33, Philips, Netherlands) was performed before and after cardiopulmonary bypass according to the guidelines of the ASE/SCA. FAC was determined in the transgastric midpapillary short-axis view. LV EF was measured in the midesophageal four- and two-chamber view. For calculation of the Tei Index, the deep transgastric and the midesophageal four-chamber view were used. Statistical analysis was performed with SPSS 17.0. values are expressed as mean with standard deviation. LV FAC and EF decreased significantly after MV repair (FAC: 56\pm12% vs. 50\pm14%, P\textless0.001; EF: 58\pm11 vs. 50\pm12\textgreek’E P\textless0.001). The Tei Index decreased from 0.66\pm0.23 before MV repair to 0.41\pm0.19 afterwards (P\textless0.001). No relationship between pre-operative Tei Index and post-operative FAC or post-operative EF were found (FAC: r=-0.061, P=0.554; EF: r=-0.29, P=0.771). Conclusion: Pre-operative Tei Index is not a good predictor for post-operative FAC and EF in patients undergoing MV repair.

Authors: Chirojit Mukherjee, Steffen Groeger, Maurice Hogan, Markus Scholz, Udo X. Kaisers, Joerg Ender

Date Published: 2012

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

Biomathematische Modellierung von Therapiewirkungen bei Lymphomerkrankungen - Ein Beitrag zur Medizinischen Systembiologie
Genetical Statistics and Systems Biology

Abstract

Not specified

Author: Markus Scholz

Date Published: 2012

Publication Type: Journal article

Rationale and design of the Leipzig (LIFE) Heart Study: phenotyping and cardiovascular characteristics of patients with coronary artery disease
Genetical Statistics and Systems Biology

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

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