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Featured researches published by N. Maass.


Hypertension in Pregnancy | 2012

The Evaluation of the Oxidative State of Low-Density Lipoproteins in Intrauterine Growth Restriction and Preeclampsia

Ulrich Pecks; Raphaela Caspers; Barbara Schiessl; Dirk O. Bauerschlag; Daniela Piroth; N. Maass; W. Rath

Objective. To evaluate the oxidative state of lipoproteins in pregnancies complicated by intrauterine growth restriction (IUGR) in comparison to preeclampsia (PE) and healthy pregnant control subjects (CN). Methods. Maternal serum of 20 PE, 29 IUGR, and 29 gestational age-matched CN were analyzed. Total cholesterol (TC), low-density lipoprotein (LDL)-bound cholesterol (LDL-C), and oxidized LDL (oxLDL) concentration were measured once between 25 and 34 weeks of gestation. Statistical estimates were performed by Students t-test. Results. Serum concentrations of LDL-C and TC were significantly reduced in IUGR [LDL-C: CN – mean = 146 mg/dL, SD = ± 40.1; IUGR – mean = 102 mg/dL, SD = ± 27.3 (p < 0.0001); PE – mean = 130 mg/dL, SD = 38.8 mg/dL; TC: CN – mean = 259/dL, SD = ± 46.8; IUGR – mean = 218 mg/dL, SD = ± 35.0 (p < 0.001); PE – mean = 244 mg/dL, SD = 48.2]. There was no significant difference in oxLDL/LDL-C ratio within the three groups (CN: mean = 0.76, SD = 0.24; IUGR: mean = 0.74, SD = 0.12; PE: mean = 0.77, SD = 0.22). Conclusion. Our results show a lower maternal LDL-C and TC concentration in IUGR pregnancies. These data contribute to the hypothesis of a decreased cholesterol supply to the fetus in IUGR. However, we could not confirm the hypothesis of an altered oxidative state in neither IUGR nor PE.


European Journal of Obstetrics & Gynecology and Reproductive Biology | 2012

Differential expression of MMP-2, MMP-9 and PCNA in endometriosis and endometrial carcinoma

Marion T. Weigel; Julia Krämer; Christian Schem; Antonia Wenners; Ibrahim Alkatout; Walter Jonat; N. Maass; Christoph Mundhenke

OBJECTIVES Endometriosis is a common gynaecological disease with clinical symptoms such as chronic pain, infertility and intra-abdominal adhesions. Different theories on the pathogenesis of endometriosis and especially its aggressive subtype with infiltrative growth have been discussed. The objective of this study is to evaluate differences in proliferation and invasive properties of invasive colorectal endometriosis, superficial peritoneal endometriosis and endometrial carcinoma (G1 and G2). STUDY DESIGN Paraffin embedded tissues of peritoneal endometriosis, endometriosis of the intestine and endometrial carcinoma from 97 patients were stained immunohistochemically to assess differences in expression patterns of matrix metalloproteinases (MMP-2, MMP-9) as markers of invasion and the marker of proliferation PCNA. MMP expression was evaluated using the Immuno Reactive Score (IRS) (combining positive cell ratio and staining intensity) and PCNA expression was assessed as the percentage of positively stained cells in representative areas. RESULTS MMP-2, MMP-9 and PCNA showed differential expression patterns in the different tissues examined. MMP-2 and PCNA expression was stronger in invasive colorectal endometriosis than in superficial peritoneal endometriosis (p=0.0394). MMP-9, however, was more frequently expressed in peritoneal endometriosis (59.1%) than in colorectal endometriosis (44.4%). This result did not reach statistical significance. When colorectal endometriosis was compared to low grade endometrial carcinoma, proliferation detected by PCNA was significantly higher in endometriosis (p=0.0008). MMP-2 and MMP-9 showed higher expression in endometrial carcinoma than in endometriosis. CONCLUSIONS There are obvious differences in expression patterns of MMP-2, MMP-9 and PCNA in different stages of endometriosis and in endometrial cancer. These markers can be helpful to evaluate aggressiveness and invasiveness of endometriosis in different localizations. The results obtained could be of relevance for a better understanding of the pathogenesis of endometriosis and the development of an individual therapy concept.


Journal of Translational Medicine | 2015

Fatty acid synthase overexpression: target for therapy and reversal of chemoresistance in ovarian cancer

Dirk O. Bauerschlag; N. Maass; Peter Leonhardt; Frederik A. Verburg; Ulrich Pecks; Felix Zeppernick; Agnieszka Morgenroth; Felix M. Mottaghy; Rene Tolba; I. Meinhold-Heerlein; Karen Bräutigam

BackgroundFatty acid synthase (FASN) is crucial to de novo long-chain fatty acid synthesis, needed to meet cancer cells’ increased demands for membrane, energy, and protein production.MethodsWe investigated FASN overexpression as a therapeutic and chemosensitization target in ovarian cancer tissue, cell lines, and primary cell cultures. FASN expression at mRNA and protein levels was determined by quantitative real-time polymerase chain reaction and immunoblotting and immunohistochemistry, respectively. FASN inhibition’s impact on cell viability, apoptosis, and fatty acid metabolism was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide assay, cell death detection enzyme-linked immunosorbent assay, immunoblotting, and 18 F-fluoromethylcholine uptake measurement, respectively.ResultsRelative to that in healthy fallopian tube tissue, tumor tissues had 1.8-fold average FASN protein overexpression; cell lines and primary cultures had 11-fold–100-fold mRNA and protein overexpression. In most samples, the FASN inhibitor cerulenin markedly decreased FASN expression and cell viability and induced apoptosis. Unlike concomitant administration, sequential cerulenin/cisplatin treatment reduced cisplatin’s half maximal inhibitory concentration profoundly (up to 54%) in a cisplatin-resistant cell line, suggesting platinum (re)sensitization. Cisplatin-resistant cells displayed lower 18 F-fluoro-methylcholine uptake than did cisplatin-sensitive cells, suggesting that metabolic imaging might help guide therapy.ConclusionsFASN inhibition induced apoptosis in chemosensitive and platinum-resistant ovarian cancer cells and may reverse cisplatin resistance.


BJUI | 2012

Two‐ and three‐/four dimensional perineal ultrasonography in men with urinary incontinence after radical prostatectomy

Ruth Kirschner-Hermanns; Laila Najjari; Bernhard Brehmer; Regina Blum; Vikram Zeuch; N. Maass; Axel Heidenreich

Study Type – Diagnostic (case control)


Fertility and Sterility | 2011

Two-dimensional gel electrophoresis in peritoneal fluid samples identifies differential protein regulation in patients suffering from peritoneal or ovarian endometriosis

Monika M. Wölfler; I. Meinhold-Heerlein; Linda Söhngen; W. Rath; Ruth Knüchel; Joseph Neulen; N. Maass; Corinna Henkel

Endometriosis is determined by local and systemic proinflammatory dysregulation and therefore differential protein expression in peritoneal fluid (PF). Of highest interest is lesion formation and the establishment and persistence of endometriosis. In this study we analyzed well-characterized PF samples of patients with ovarian or peritoneal endometriosis and compared them to control samples. We found 11 proteins differentially regulated, of which some might play a key role in the pathogenesis of endometriosis.


European Journal of Obstetrics & Gynecology and Reproductive Biology | 2015

Off-label use of misoprostol for labor induction in Germany: a national survey

F. Voigt; Tamme W. Goecke; Laila Najjari; Ulrich Pecks; N. Maass; W. Rath

OBJECTIVE Misoprostol is safe and effective for labor induction in viable pregnancies. Little is known about the prevalence of off-label use of misoprostol, and the reasons for using or not using misoprostol for labor induction. As such, a national survey was conducted in Germany to assess reliable data about the use of misoprostol in clinical practice. STUDY DESIGN A prospective study was performed in 2013 using a standardized survey questionnaire. All registered departments of obstetrics and gynecology in Germany were targeted. RESULTS Out of 783 questionnaires, 542 (69%) were returned. Three hundred and fifty-five (66%) respondents reported that they use misoprostol for labor induction in viable term pregnancies, and 183 (34%) respondents reported that they never use misoprostol for this indication. The most common reasons given for using misoprostol in labor induction were: effectiveness (40%), good patient acceptance (35%), established/well proven in clinical practice (35%) and cost-effectiveness (32%). The most common reasons given for not using misoprostol were lack of licence (off-label use, 69%) and uncertainty of the legal situation (27%). CONCLUSION Although misoprostol is not licensed in Germany for obstetric indications, the vast majority of respondents (66%) reported that they use misoprostol for labor induction. The main reasons for not using misoprostol for labor induction in Germany are legal concerns rather than lack of scientific evidence. Cost-effective medications with evidence-based effectiveness and safety should be supported by a clear statement from national medical societies.


Fertility and Sterility | 2013

Reduced hemopexin levels in peritoneal fluid of patients with endometriosis

Monika M. Wölfler; I. Meinhold-Heerlein; Corinna Henkel; W. Rath; Joseph Neulen; N. Maass; Karen Bräutigam

OBJECTIVE To study altered hemopexin concentrations in peritoneal fluid (PF) samples from patients with endometriosis. Recent data implicate a role of altered iron metabolism in endometriosis patients. Hemopexin is the major transport protein for heme. Like iron, heme exposure to the epithelial surface can provoke oxidative stress on the peritoneal epithelium. Therefore, altered hemopexin concentrations and heme scavenging in PF might play a role in the pathophysiology of endometriosis. DESIGN Prospective explorative study. SETTING Academic tertiary care center. PATIENT(S) Eighty symptomatic patients scheduled for laparoscopy for the diagnosis and/or therapy of endometriosis. INTERVENTION(S) Aspiration of PF samples during laparoscopy. MAIN OUTCOME MEASURE(S) Hemopexin and heme concentration in PF. RESULT(S) At laparoscopy, 47 of 80 (58.8%) patients exhibited endometriosis, and 33 (41.2%) were proven disease-free (CO). By means of ELISA significantly lower concentrations of hemopexin in the samples from patients with endometriosis (endometriosis 0.377 ± 0.16 mg/mL) compared with controls (disease-free 0.479 ± 0.20 mg/mL) could be demonstrated. Heme levels in the samples were not significantly different between groups (endometriosis 9.130 ± 6.124 μM and disease-free 9.990 ± 4.485 μM). There was no significant correlation between heme and hemopexin levels (Pearsons correlation coefficient r = -0.146). Demographic data between the groups were comparable. CONCLUSION(S) These data provide further evidence that hemopexin is significantly down-regulated in PF samples from patients with endometriosis compared with controls. This study confirms recent findings in two-dimensional gel electrophoresis demonstrating a down-regulation of hemopexin in PF from patients with endometriosis in a larger series of samples.


American Journal of Reproductive Immunology | 2012

Anti‐oxidized Low‐Density Lipoprotein (oxLDL) Antibody Levels are not Related to Increasing Circulating oxLDL Concentrations During the Course of Pregnancy

Ulrich Pecks; Dagmar Tillmann; Sabine Ernst; N. Maass; I. Meinhold-Heerlein

To address the question of whether the high levels of oxidative modified low‐density lipoproteins (oxLDL) in pregnancy are opposed by an appropriate humoral autoimmune response providing anti‐oxLDL autoantibodies in maternal serum of healthy women throughout gestation.


Zeitschrift Fur Geburtshilfe Und Neonatologie | 2012

Determination of maternal and foetal serum lipid profile and placental oxidised low density lipoprotein accumulation in preeclampsia and normotensive pregnancies

Ulrich Pecks; R. Caspers; K. Sosnowsky; N. Freerksen; N. Maass; Berthold Huppertz; W. Rath

BACKGROUND Oxidised low density lipoproteins (oxLDL) are key players in the development of atherosclerotic cardiovascular diseases. Since there are similarities between the pathogenesis of preeclampsia and atherosclerosis we hypothesised an increased accumulation of oxLDL at the materno-foetal and foeto-foetal interface within the placental tissue of preeclamptic women compared to women with normotensive pregnancies (controls). Moreover, we analysed maternal and foetal serum lipid parameters. PATIENTS AND METHODS oxLDL was determined by immunohistochemistry in placental paraffin sections of 14 women suffering from preeclampsia (30th-39th week of gestation) and compared to 28 preterm and term deliveries (25th-40th week of gestation). 10 high power fields were chosen randomly by the newCAST software and oxLDL expression was analysed via standardised methods by 2 independent and blinded investigators. Maternal and foetal triglycerides, total cholesterol, LDL cholesterol and HDL cholesterol were measured. Statistical examination was carried out by the Mann-Whitney test. RESULTS oxLDL was found in villous trophoblast and placental endothelium. No significant differences were observed in expression intensity between preeclampsia and controls. Maternal and foetal triglyceride levels were significantly increased in preeclampsia compared to controls (pre-eclampsia mothers: 293 [SD 87.4] mg/dL, controls: 214 [SD 89.4] mg/dL, p=0.0097; preeclampsia foetuses: 26 [SD 16.6] mg/dL, controls: 18 [SD 10.4] mg/dL, p=0.0463). No significant differences in other lipid concentrations were found. CONCLUSIONS We could not confirm our initial hypothesis of an increased oxLDL accumulation in placental tissue of preeclampsia. However, preeclampsia is a condition of dyslipidaemia affecting both maternal and foetal serum with implications for development and programming of cardiovascular diseases in later life.


Genes, Chromosomes and Cancer | 2013

Breakpoint characterization of the der(19)t(11;19)(q13;p13) in the ovarian cancer cell line SKOV‐3

Wiebke Onkes; Regina Fredrik; Francesca Micci; Benjamin J Schönbeck; José I. Martín-Subero; Reinhard Ullmann; Felix Hilpert; Karen Bräutigam; Ottmar Janssen; N. Maass; Reiner Siebert; Sverre Heim; Norbert Arnold; Jörg Weimer

About 20% of ovarian carcinomas show alterations of 19p13 and/or 19q13 in the form of added extra material whose origin often is from chromosome 11. Based on earlier spectral karyotype analysis of the ovarian cancer cell line SKOV‐3, which shows an unbalanced translocation der(19)t(11;19), the aim of this study was to determine the precise breakpoints of that derivative chromosome. After rough delimitation of the breakpoints of microdissected derivative chromosomes by array analysis, we designed a matrix of primers spanning 11q13.2 and 19p13.2 detecting multiple amplicons on genomic and cDNA. Sequencing the amplicons, accurate localization of both breakpoints on both chromosomes was possible and we found that exon 14 of HOOK2 from chromosome 19 and exon 2 of ACTN3 from chromosome 11 were fused in the derivative chromosome. The breakpoint in the HOOK2 gene was in an intrinsic triplet of nucleic acids leading to a shift in the ACTN3 reading frame in the derivative chromosome. This frameshift alteration should give rise to an early stop codon causing a loss of function of ACTN3. Signals in two‐dimensional Western blotting exactly match to calculated molecular mass and the isoelectric point of the fusion protein.

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W. Rath

RWTH Aachen University

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F. Voigt

RWTH Aachen University

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