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Grieshaber P, Gehron J, Bongert M, Schäfer S, Fiebich M, Krombach G, Böning A. Exploration of the Mixing Phenomena during Interaction of Internal and External Circulations (EMPACs): Developing an in-vitro and in-silico Model of the Human Circulation. Thorac Cardiovasc Surg 2016. [DOI: 10.1055/s-0036-1571485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Cierpiol S, Schäfer S, Gossner J. Compression of the medulla oblongata due to an elongated vertebral artery is a common incidental finding on MRI of the brain. Acta Neurol Belg 2015; 115:841-2. [PMID: 26008725 DOI: 10.1007/s13760-015-0488-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Accepted: 05/13/2015] [Indexed: 11/27/2022]
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Abstract
Abstract. Recently, Sui, He, and Humphreys (2012) introduced a new paradigm to measure perceptual self-prioritization processes. It seems that arbitrarily tagging shapes to self-relevant words (I, my, me, and so on) leads to speeded verification times when matching self-relevant word shape pairings (e.g., me – triangle) as compared to non-self-relevant word shape pairings (e.g., stranger – circle). In order to analyze the level at which self-prioritization takes place we analyzed whether the self-prioritization effect is due to a tagging of the self-relevant label and the particular associated shape or due to a tagging of the self with an abstract concept. In two experiments participants showed standard self-prioritization effects with varying stimulus features or different exemplars of a particular stimulus-category suggesting that self-prioritization also works at a conceptual level.
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Roth B, Becker N, Romeyke S, Schäfer S, Domnick F, Spinath FM. Intelligence and school grades: A meta-analysis. INTELLIGENCE 2015. [DOI: 10.1016/j.intell.2015.09.002] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Burki U, Greally E, Laval S, Schäfer S, Straub V. G.P.120. Neuromuscul Disord 2014. [DOI: 10.1016/j.nmd.2014.06.150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Bernemann C, Hülsewig C, Ruckert C, Schäfer S, Blümel L, Hempel G, Götte M, Greve B, Barth PJ, Kiesel L, Liedtke C. Influence of secreted frizzled receptor protein 1 (SFRP1) on neoadjuvant chemotherapy in triple negative breast cancer does not rely on WNT signaling. Mol Cancer 2014; 13:174. [PMID: 25033833 PMCID: PMC4110378 DOI: 10.1186/1476-4598-13-174] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 07/09/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Triple negative breast cancer (TNBC) is characterized by lack of expression of both estrogen and progesterone receptor as well as lack of overexpression or amplification of HER2. Despite an increased probability of response to chemotherapy, many patients resistant to current chemotherapy regimens suffer from a worse prognosis compared to other breast cancer subtypes. However, molecular determinants of response to chemotherapy specific to TNBC remain largely unknown. Thus, there is a high demand for biomarkers potentially stratifying triple negative breast cancer patients for neoadjuvant chemotherapies or alternative therapies. METHODS In order to identify genes correlating with both the triple negative breast cancer subtype as well as response to neoadjuvant chemotherapy we employed publicly available gene expression profiles of patients, which had received neoadjuvant chemotherapy. Analysis of tissue microarrays as well as breast cancer cell lines revealed correlation to the triple negative breast cancer subtype. Subsequently, effects of siRNA-mediated knockdown on response to standard chemotherapeutic agents as well as radiation therapy were analyzed. Additionally, we evaluated the molecular mechanisms by which SFRP1 alters the carcinogenic properties of breast cancer cells. RESULTS SFRP1 was identified as being significantly overexpressed in TNBC compared to other breast cancer subtypes. Additionally, SFRP1 expression is significantly correlated with an increased probability of positive response to neoadjuvant chemotherapy. Knockdown of SFRP1 in triple negative breast cancer cells renders the cells more resistant to standard chemotherapy. Moreover, tumorigenic properties of the cells are modified by knockdown, as shown by both migration or invasion capacity as well reduced apoptotic events. Surprisingly, we found that these effects do not rely on Wnt signaling. Furthermore, we show that pro-apoptotic as well as migratory pathways are differentially regulated after SFRP1 knockdown. CONCLUSION We could firstly show that SFRP1 strongly correlates with the triple negative breast cancer subtype and secondly, that SFRP1 might be used as a marker stratifying patients to positively respond to neoadjuvant chemotherapy. The mechanisms by which tumor suppressor SFRP1 influences carcinogenic properties of cancer cells do not rely on Wnt signaling, thereby demonstrating the complexity of tumor associated signaling pathways.
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Langsch S, Schäfer S, Tschan M, Vassella E. 226: Role of EGFR-regulated microRNAs in malignant processes of non-small cell lung cancer. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)50197-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Schäfer S, Alejandre-Lafont E, Schmidt T, Gizewski E, Fiebich M, Krombach G. Dose Management for X-Ray and CT: Systematic Comparison of Exposition Values from Two Institutes to Diagnostic Reference Levels and Use of Results for Optimisation of Exposition. ROFO-FORTSCHR RONTG 2014; 186:785-94. [DOI: 10.1055/s-0033-1356425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hofmann T, Schäfer S, Linseisen M, Sytik L, Gudermann T, Chubanov V. Activation of TRPM7 channels by small molecules under physiological conditions. Pflugers Arch 2014; 466:2177-89. [PMID: 24633576 DOI: 10.1007/s00424-014-1488-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 02/17/2014] [Accepted: 02/18/2014] [Indexed: 01/07/2023]
Abstract
Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) is a cation channel covalently linked to a protein kinase domain. TRPM7 is ubiquitously expressed and regulates key cellular processes such as Mg(2+) homeostasis, motility, and proliferation. TRPM7 is involved in anoxic neuronal death, cardiac fibrosis, and tumor growth. The goal of this work was to identify small molecule activators of the TRPM7 channel and investigate their mechanism of action. We used an aequorin bioluminescence-based assay to screen for activators of the TRPM7 channel. Valid candidates were further characterized using patch clamp electrophysiology. We identified 20 drug-like compounds with various structural backbones that can activate the TRPM7 channel. Among them, the δ opioid antagonist naltriben was studied in greater detail. Naltriben's action was selective among the TRP channels tested. Naltriben activates TRPM7 currents without prior depletion of intracellular Mg(2+) even under conditions of low PIP2. Moreover, naltriben interfered with the effect of the TRPM7 inhibitor NS8593. Finally, our experiments with TRPM7 variants carrying mutations in the pore, TRP, and kinase domains indicate that the site of TRPM7 activation by this small-molecule ligand is most likely located in or near the TRP domain. In conclusion, we identified the first organic small-molecule activators of TRPM7 channels, thus providing new experimental tools to study TRPM7 function in native cellular environments.
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Eggers J, Martino V, Reinbold R, Schäfer S, Kiesel L, Greve B, Götte M. microRNA miR-200b differentially affects proliferation, invasiveness and stemness of endometriotic cells by targeting the transcription factors KLF4, ZEB1 and ZEB2. Exp Clin Endocrinol Diabetes 2014. [DOI: 10.1055/s-0034-1371993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Dettwiler M, Dennler M, Kümmerle-Fraune C, Schäfer S, Hurter K, Hilbe M. Uncommon Metastasis of an Osteosarcoma Causing Central Diabetes Insipidus in a Borsoi Dog. J Comp Pathol 2014. [DOI: 10.1016/j.jcpa.2013.11.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Dinh W, Albrecht-Küpper B, Weimann G, Schäfer S. Partieller Agonismus am Adenosin-A1-Rezeptor: Ein neues Prinzip zur Therapie der Herzinsuffizienz? Pneumologie 2013. [DOI: 10.1055/s-0033-1344886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Cuthbertson DJ, Johnson SR, Piljac-Žegarac J, Kappel J, Schäfer S, Wüst M, Ketchum REB, Croteau RB, Marques JV, Davin LB, Lewis NG, Rolf M, Kutchan TM, Soejarto DD, Lange BM. Accurate mass-time tag library for LC/MS-based metabolite profiling of medicinal plants. PHYTOCHEMISTRY 2013; 91:187-97. [PMID: 23597491 PMCID: PMC3697863 DOI: 10.1016/j.phytochem.2013.02.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/21/2013] [Accepted: 02/25/2013] [Indexed: 05/20/2023]
Abstract
We report the development and testing of an accurate mass-time (AMT) tag approach for the LC/MS-based identification of plant natural products (PNPs) in complex extracts. An AMT tag library was developed for approximately 500 PNPs with diverse chemical structures, detected in electrospray and atmospheric pressure chemical ionization modes (both positive and negative polarities). In addition, to enable peak annotations with high confidence, MS/MS spectra were acquired with three different fragmentation energies. The LC/MS and MS/MS data sets were integrated into online spectral search tools and repositories (Spektraris and MassBank), thus allowing users to interrogate their own data sets for the potential presence of PNPs. The utility of the AMT tag library approach is demonstrated by the detection and annotation of active principles in 27 different medicinal plant species with diverse chemical constituents.
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Schäfer S, Stroszczynski C, Heiss P. [Sufficiency in the reduction of the portosystemic pressure gradient by implantation of a second transjugular intrahepatic portosystemic shunt]. ROFO-FORTSCHR RONTG 2013; 185:666-8. [PMID: 23696016 DOI: 10.1055/s-0033-1335139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Gossner J, Schäfer S. Usefulness of the bolus-tracking baseline scan for the diagnosis of hepatic steatosis in abdominal computed tomography: a feasibility study. ISRN RADIOLOGY 2013; 2013:147632. [PMID: 24959557 PMCID: PMC4045524 DOI: 10.5402/2013/147632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 04/07/2013] [Indexed: 11/29/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a common pathology in western societies. Unenhanced computed tomography (CT) of the liver is a valuable tool in determining the presence of steatosis hepatis, but in most departments standard CT protocols of abdomen often do not include unenhanced scans anymore. In a small series of 22 patients the liver density was measured in the acquired low-dose baseline scan for bolus tracking and was compared to the measurement in a regular unenhanced CT scan of the upper abdomen. The mean difference between the unenhanced CT scan and the low-dose baseline scan was 3.4 HU (range 0.2-8.6 HU); the difference between these two scans was 5 HU or smaller in 82% of the patients. There was a significant difference between the two used CT scanners; this has to be kept in mind before implementing this approach into daily practice. All but one patient with fatty liver disease on unenhanced CT were diagnosed using the baseline scan. The baseline scan for bolus tracking may be useful for the diagnosis or in the followup of fatty liver disease.
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Roswag I, Kampschulte M, Dahms J, Schäfer S, Krombach G. Röntgen des Thorax bei Intensivpatienten mit dem „Manuellen Mobilkassetteneinzug Ilsro“. ROFO-FORTSCHR RONTG 2013. [DOI: 10.1055/s-0033-1346446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Schäfer S, Hellrung E, Stoelben E, Windisch W, Karagiannidis C. Akute infektgetriggerte respiratorische Azidose bei einem 24-jährigen Patienten mit kongenitaler Myasthenie. Pneumologie 2013. [DOI: 10.1055/s-0033-1334550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Boretti FS, Sieber-Ruckstuhl NS, Schäfer S, Baumgartner C, Riond B, Hofmann-Lehmann R, Reusch CE. Duration of t4 suppression in hyperthyroid cats treated once and twice daily with transdermal methimazole. J Vet Intern Med 2013; 27:377-81. [PMID: 23398124 DOI: 10.1111/jvim.12040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Revised: 11/13/2012] [Accepted: 12/06/2012] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Transdermal methimazole is an acceptable alternative to oral treatment for hyperthyroid cats. There are, however, no studies evaluating the duration of T4 suppression after transdermal methimazole application. Such information would be valuable for therapeutic monitoring. OBJECTIVE To assess variation in serum T4 concentration in hyperthyroid cats after once- and twice-daily transdermal methimazole administration. ANIMALS Twenty client-owned cats with newly diagnosed hyperthyroidism. METHODS Methimazole was formulated in a pluronic lecithin organogel-based vehicle and applied to the pinna of the inner ear at a starting dose of 2.5 mg/cat q12h (BID group, 10 cats) and 5 mg/cat q24h (SID group, 10 cats). One and 3 weeks after starting treatment, T4 concentrations were measured immediately before and every 2 hours after gel application over a period of up to 10 hours. RESULTS Significantly decreased T4 concentrations were observed in week 1 and 3 compared with pretreatment concentrations in both groups. All cats showed sustained suppression of T4 concentration during the 10-hour period, and T4 concentrations immediately before the next methimazole treatment were not significantly different compared with any time point after application, either in the BID or SID groups. CONCLUSIONS Because transdermal methimazole application led to prolonged T4 suppression in both the BID and SID groups, timing of blood sampling does not seem to be critical when assessing treatment response.
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Rinke S, Schäfer S, Lange K, Gersdorff N, Roediger M. Practice-based clinical evaluation of metal-ceramic and zirconia molar crowns: 3-year results. J Oral Rehabil 2012; 40:228-37. [PMID: 23211063 DOI: 10.1111/joor.12018] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2012] [Indexed: 11/28/2022]
Abstract
This practice-based study evaluates the clinical performance of conventionally luted metal-ceramic and zirconia molar crowns fabricated with pronounced anatomical core design and a prolonged cooling period of the veneering porcelain. Fifty-three patients were treated from 07/2008 until 07/2009 with either metal-ceramic crowns (MCC) (high-noble alloy + low-fusing porcelain) or zirconia crowns (Cercon System, DeguDent, Germany). Forty-nine patients (30 women/19 men) with 100 restorations (metal-ceramic: 48/zirconia: 52, mean observational period: 36·5 ± 6 months) participated in a clinical follow-up examination and were included in the study. Time-dependent survival (in situ criteria), success (event-free restorations) and chipping rates (defects of the veneering ceramics) were calculated according to the Kaplan-Meier method and analysed in relation to the crown fabrication technique, using a Cox regression model (P < 0·05). Three complete failures (metal-ceramic: 1, zirconia: 2) were recorded (survival rate after 3 years: metal-ceramic: 97·6%, zirconia: 95·2%). Of the metal-ceramic restorations, 90·9% remained event-free (two ceramic fractures, one endodontic treatment), whereas the success rate for the zirconia was 86·8% (two ceramic fractures, one endodontic treatment, one secondary caries). No significant differences in survival (P = 0·53), success (P = 0·49) and ceramic fracture rates (P = 0·57) were detected. The combination of a pronounced anatomical core design and a modified firing of the veneering porcelain for the fabrication of zirconia molar crowns resulted in a 3-year survival, success and chipping rate comparable to MCC.
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Chubanov V, Mederos y Schnitzler M, Meißner M, Schäfer S, Abstiens K, Hofmann T, Gudermann T. Natural and synthetic modulators of SK (K(ca)2) potassium channels inhibit magnesium-dependent activity of the kinase-coupled cation channel TRPM7. Br J Pharmacol 2012; 166:1357-76. [PMID: 22242975 DOI: 10.1111/j.1476-5381.2012.01855.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Transient receptor potential cation channel subfamily M member 7 (TRPM7) is a bifunctional protein comprising a TRP ion channel segment linked to an α-type protein kinase domain. TRPM7 is essential for proliferation and cell growth. Up-regulation of TRPM7 function is involved in anoxic neuronal death, cardiac fibrosis and tumour cell proliferation. The goal of this work was to identify non-toxic inhibitors of the TRPM7 channel and to assess the effect of blocking endogenous TRPM7 currents on the phenotype of living cells. EXPERIMENTAL APPROACH We developed an aequorin bioluminescence-based assay of TRPM7 channel activity and performed a hypothesis-driven screen for inhibitors of the channel. The candidates identified were further assessed electrophysiologically and in cell biological experiments. KEY RESULTS TRPM7 currents were inhibited by modulators of small conductance Ca²⁺ -activated K⁺ channels (K(Ca)2.1-2.3; SK) channels, including the antimalarial plant alkaloid quinine, CyPPA, dequalinium, NS8593, SKA31 and UCL 1684. The most potent compound NS8593 (IC₅₀ 1.6 µM) specifically targeted TRPM7 as compared with other TRP channels, interfered with Mg²⁺ -dependent regulation of TRPM7 channel and inhibited the motility of cultured cells. NS8593 exhibited full and reversible block of native TRPM7-like currents in HEK 293 cells, freshly isolated smooth muscle cells, primary podocytes and ventricular myocytes. CONCLUSIONS AND IMPLICATIONS This study reveals a tight overlap in the pharmacological profiles of TRPM7 and K(Ca)2.1-2.3 channels. NS8593 acts as a negative gating modulator of TRPM7 and is well-suited to study functional features and cellular roles of endogenous TRPM7.
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Schäfer S, Stroszczynski C, Müller-Wille R. [CVC malposition with partial anomalous pulmonary venous: a rare cause of a local pulmonary edema]. ROFO-FORTSCHR RONTG 2012; 185:69-71. [PMID: 22893487 DOI: 10.1055/s-0032-1313132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Schäfer S, Hamer B, Treursić B, Möhlenkamp C, Spira D, Korlević M, Reifferscheid G, Claus E. Comparison of bioaccumulation and biomarker responses in Dreissena polymorpha and D. bugensis after exposure to resuspended sediments. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2012; 62:614-627. [PMID: 22231661 DOI: 10.1007/s00244-011-9735-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 11/17/2011] [Indexed: 05/31/2023]
Abstract
The zebra mussel Dreissena polymorpha is widely used as sentinel organism for the assessment of environmental contamination in freshwater environments. However, in the River Rhine (Germany), the D. polymorpha population is declining, whereas the closely related quagga mussel D. bugensis is found in high numbers at some sites. In the present laboratory study, D. polymorpha and D. bugensis were exposed to resuspended native sediments for ≤2 weeks. Wet sediments (<63 μm, 100 mg l(-1) dry weight) were used as surrogate suspended particulate matter to mimic one of the mussels' main uptake route for chemicals. The sediments were sampled in (1) the River Elbe in Dessau, a site known to be highly polluted with, e.g., organochlorine (OC) pesticides and (2) at a relatively unpolluted site in Havelberg in the River Havel, one of the Elbe's tributaries. Chemical analysis of persistent OC compounds (seven polychlorinated biphenyls [PCBs], DDT and its metabolites (DDX), hexachlorocylohexanes [HCHs], and hexachlorobenzene [HCB]) in soft tissue of mussels showed significantly greater values of PCBs 101, 118, 153, 138, 180, the sum of seven PCBs, and p,p'-DDD in D. bugensis compared with D. polymorpha. Fourteen days of exposure to Dessau sediment increased the concentration of p,p'-DDE and p,p'-DDD, as well as the sum of DDX, in both species compared with Havelberg sediment. Interspecific differences were less pronounced when regarding chemical concentrations with lipid content instead of dry-weight of tissue because D. bugensis had greater levels of total lipid than D. polymorpha. DNA damage in gills, as measured with the comet assay, was greater in D. bugensis compared with D. polymorpha. Simultaneously, the content of heat-shock protein (hsp70) in gills was greater in D. polymorpha than in D. bugensis. DNA damage and hsp70 were not induced by exposure time or sediment type. This study shows that D. bugensis and D. polymorpha may differ in their bioaccumulation potential of OC pesticides as well as their levels of DNA damage and hsp70. Therefore, more investigations are needed before quagga mussel can be used as alternative test organism for the zebra mussel.
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Schäfer S, Wege A, Brockhoff G, Schardt K, Wiggermann P, Stroszczynski C, Jung EM. Hochauflösender kontrastmittelverstärkter Ultraschall (CEUS) zur Detektion und Beurteilung der Mikrovaskularisation im Kleintiermodell zum Therapiemonitoring des Effektes von Trastuzumab/IL15. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0032-1311473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Thondorf I, Voigt V, Schäfer S, Gebauer S, Zebisch K, Laug L, Brandsch M. Three-dimensional quantitative structure–activity relationship analyses of substrates of the human proton-coupled amino acid transporter 1 (hPAT1). Bioorg Med Chem 2011; 19:6409-18. [DOI: 10.1016/j.bmc.2011.08.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 08/22/2011] [Accepted: 08/28/2011] [Indexed: 10/17/2022]
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Lehnen H, Schäfer S, Reineke T, Puchooa A, Maiwald R, Zechner U. Twin Pregnancies Conceived Spontaneously and by ART (Assisted Reproductive Technologies) – a Retrospective Analysis and Review. Geburtshilfe Frauenheilkd 2011. [DOI: 10.1055/s-0031-1280130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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Heiles S, Schäfer S, Schäfer R. On the rotational temperature and structure dependence of electric field deflection experiments: A case study of germanium clusters. J Chem Phys 2011; 135:034303. [DOI: 10.1063/1.3610390] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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Schäfer S, Anschlag J, Nettersheim D, Haas N, Pawig L, Schorle H. The role of BLIMP1 and its putative downstream target TFAP2C in germ cell development and germ cell tumours. ACTA ACUST UNITED AC 2011; 34:e152-8; discussion e158-9. [PMID: 21564135 DOI: 10.1111/j.1365-2605.2011.01167.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
During the past years, much information has been gathered regarding the genetic and epigenetic programmes leading to the specification and maintenance of primordial germ cells. Expression of the transcriptional regulator BLIMP1 (PRDM1) is regarded as the main event in germ cell specification. BLIMP1 induces a set of target genes, one of them being transcription factor TFAP2C (AP-2γ, Tcfap2c). In murine loss of function models Blimp1 and Tcfap2c share an identical phenotype, strengthening the assumption that they act in the same pathway. One major role of this pathway is the inhibition of somatic differentiation in germ cells. BLIMP1 and TFAP2C are also expressed in carcinoma in situ (CIS, IGCNU, TIN) and in seminoma. As pointed out herein, the presence of both proteins helps to explain the undifferentiated nature of these germ cell tumours. In addition, we performed a meta-analysis of high-throughput datasets searching for TFAP2C/Tcfap2c target genes. This analysis leads us to suggest Nanos3, Dmrt1 and Dnmt3b as potential TFAP2C/Tcfap2c target genes with relevance to germ cell development and germ cell tumours.
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Müller-Höcker J, Horvath R, Schäfer S, Hessel H, Müller-Felber W, Kühr J, Copeland WC, Seibel P. Mitochondrial DNA depletion and fatal infantile hepatic failure due to mutations in the mitochondrial polymerase γ (POLG) gene: a combined morphological/enzyme histochemical and immunocytochemical/biochemical and molecular genetic study. J Cell Mol Med 2011; 15:445-56. [PMID: 19538466 PMCID: PMC3822808 DOI: 10.1111/j.1582-4934.2009.00819.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Accepted: 05/06/2009] [Indexed: 11/27/2022] Open
Abstract
Combined morphological, immunocytochemical, biochemical and molecular genetic studies were performed on skeletal muscle, heart muscle and liver tissue of a 16-months boy with fatal liver failure. The pathological characterization of the tissues revealed a severe depletion of mtDNA (mitochondrial DNA) that was most pronounced in liver, followed by a less severe, but still significant depletion in skeletal muscle and the heart. The primary cause of the disease was linked to compound heterozygous mutations in the polymerase γ (POLG) gene (DNA polymerase γ; A467T, K1191N). We present evidence, that compound heterozygous POLG mutations lead to tissue selective impairment of mtDNA replication and thus to a mosaic defect pattern even in the severely affected liver. A variable defect pattern was found in liver, muscle and heart tissue as revealed by biochemical, cytochemical, immunocytochemical and in situ hybridization analysis. Functionally, a severe deficiency of cytochrome-c-oxidase (cox) activity was seen in the liver. Although mtDNA depletion was detected in heart and skeletal muscle, there was no cox deficiency in these tissues. Depletion of mtDNA and microdissection of cox-positive or negative areas correlated with the histological pattern in the liver. Interestingly, the mosaic pattern detected for cox-activity and mtDNA copy number fully aligned with the immunohistologically revealed defect pattern using Pol γ, mtSSB- and mtTFA-antibodies, thus substantiating the hypothesis that nuclear encoded proteins located within mitochondria become unstable and are degraded when they are not actively bound to mtDNA. Their disappearance could also aggravate the mtDNA depletion and contribute to the non-homogenous defect pattern.
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Lehnen H, Schäfer S, Poarangan C, Havers N, Zechner U. Eindeutige Determinierung der Zygosität von gleichgeschlechtlichen Gemini mittels Mikrosatelliten-PCR-Analyse. Geburtshilfe Frauenheilkd 2011. [DOI: 10.1055/s-0030-1250615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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80
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Rinke S, Schäfer S, Roediger M. Complication rate of molar crowns: a practice-based clinical evaluation. INTERNATIONAL JOURNAL OF COMPUTERIZED DENTISTRY 2011; 14:203-218. [PMID: 22141230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This practice-based study evaluates the initial clinical performance of conventionally luted metal-ceramic and zirconia molar crowns fabricated with a prolonged cooling period of the veneering porcelain. Forty-nine patients were treated (group A: high precious alloy + low fusing porcelain; group B: zirconia crowns). All zirconia crowns were veneered with a modified porcelain firing cycle including a 6-minute cooling period. Ninety-two restorations (74 vital abutments/18 nonvital abutments) were evaluated after a mean observation period of 18.2 +/- 4.6 months. No complete failures or loss of vitality were recorded in either group. Two events were recorded in group A (1 loss of retention/1 minor ceramic chipping < 2 mm2). The third event occurred in group B (minor ceramic chipping <2 mm2). All ceramic defects could be polished intraorally. Statistical analysis revealed non-significant differences in success rates (p = 0.91) of metal-ceramic and zirconia crowns fabricated with a modified porcelain firing. The modified firing of the zirconia porcelain seems to decrease the risk for early ceramic chipping in the molar area, leading to a technical complication rate comparable to that of metal-ceramic crowns.
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81
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Schäfer S, Schiffmann JH. Tosade-de pointes-Tachykardie bei Long-QT-Syndrom-Patienten unter Hypothermie-Behandlung. KLINISCHE PADIATRIE 2010. [DOI: 10.1055/s-0030-1261555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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82
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Schupp N, Queisser N, Wolf M, Kolkhof P, Bärfacker L, Schäfer S, Heidland A, Stopper H. Aldosterone causes DNA strand breaks and chromosomal damage in renal cells, which are prevented by mineralocorticoid receptor antagonists. Horm Metab Res 2010; 42:458-65. [PMID: 20094972 DOI: 10.1055/s-0029-1243253] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Epidemiological studies exploring the connection between hypertension and cancer incidence find a higher cancer mortality in hypertensive patients, particularly elevated in hypertension associated with a stimulation of the renin-angiotensin-aldosterone system. Primary aldosteronism, with plasma aldosterone levels between 0.5 and 1 nM (18-36 ng/dL) and local aldosterone levels up to 500 nM (18,000 ng/dL), is now recognised as a more common cause for hypertension. We recently found angiotensin II to be genotoxic due to its induction of oxidative stress. Since aldosterone in higher concentrations also has oxidative effects, its potential genotoxic action in pig LLC-PK1 cells with properties of proximal tubules was analysed. DNA damage was evaluated by two test systems: the comet assay, and the micronucleus frequency test. The results showed that aldosterone concentrations starting from 10 nM (360 ng/dL) caused a significant increase of DNA damage monitored with the comet assay in LLC-PK1, while there was no change in cell vitality and proliferation. The micronucleus frequency test revealed that 10 nM aldosterone also leads to the formation of micronuclei. Furthermore, the formation of superoxide radicals in the cells by this aldosterone concentration could be detected with the superoxide-specific stain dihydroethidium. Further evidence for oxidative stress-induced DNA damage was its reversibility by the antioxidants tempol and catalase. Addition of the steroidal mineralocorticoid receptor antagonist spironolactone or the novel selective nonsteroidal antagonist (R)-BR-4628 reduced the DNA damage and the amount of superoxide radicals indicating a receptor-dependent process.
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83
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Becker E, Schurer L, Rosenbruch M, Kohlmeyer J, Schäfer K, Kuhlebrock K, Laux V, Schäfer S, Trübel H. Inhaliertes Iloprost verbessert den Gasaustausch und die Hämodynamik bei Mekonium Aspiration induziertem akuten Lungenversagen. Pneumologie 2010. [DOI: 10.1055/s-0030-1251199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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84
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Heiles S, Schäfer S, Schäfer R. Mass spectrometry and beam deflection studies of tin-lead nanoalloy clusters. Phys Chem Chem Phys 2010; 12:247-53. [PMID: 20024466 DOI: 10.1039/b917206h] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Photo-ionization mass spectrometry and electric beam deflection experiments were used to study isolated Sn(M)Pb(N) clusters (7 <or=N + M<or= 13 for tin-rich clusters, 7 <or=N + M<or= 15 for lead-rich clusters) in a molecular beam apparatus. The observed mass spectra reveal a broad abundance distribution of the bimetallic clusters in which all possible cluster compositions can be identified within the investigated size ranges. Comparison of the relative cluster intensities between pure tin or lead clusters (Sn(N+M) and Pb(N+M)) and mixed Sn(M)Pb(N) clusters indicate quite similar relative abundance distributions which can be smoothly shifted from one to the other extreme by changing the composition. The mass spectroscopic findings could be explained by assuming a substitution "alloy" formation in the Sn(M)Pb(N) cluster system. In combination, the dielectric properties were determined by passing the bimetallic clusters through an inhomogeneous electric field. The observed polarizabilities are significantly increased for most of the bimetallic clusters. This can be explained in an adiabatic polarization model by the presence of permanent electric dipole moments. These observations demonstrate how the electronic properties are not only crucially influenced by the cluster size but also by the composition of this nanoalloy model system. In addition to the enhanced polarizability, most of the measured beam profiles for tin-rich clusters show detectable beam broadenings due to the permanent dipole moments, in contrast to lead-rich clusters which possess considerable smaller dipole moments. Molecular dynamic simulations of the measured beam profile for Sn(6)Pb(1) taking theoretically calculated isomeric structures and dipole moments into account yields no completely satisfying outcome. Therefore we discuss possible reasons for the discrepancy between experimental and theoretical results.
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85
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Klein M, Schermuly R, Ellinghaus P, Kramer F, Schäfer S. Anti-Remodeling-Ansätze in der Therapie der pulmonalen Hypertonie. Pneumologie 2010. [DOI: 10.1055/s-0029-1215186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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86
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Becker E, Schäfer K, Kohlmeyer J, Rosenbruch M, Piroth W, Laux V, Schäfer S, Trübel H. Inhaliertes Iloprost verbessert selektiv den pulmonalen Gefäßwiderstand bei sekundärer pulmonaler Hypertonie im Rahmen einer akuten Lungenschädigung. Pneumologie 2010. [DOI: 10.1055/s-0029-1215181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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87
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Schäfer S, Köhler A. Gonadal lesions of female sea urchin (Psammechinus miliaris) after exposure to the polycyclic aromatic hydrocarbon phenanthrene. MARINE ENVIRONMENTAL RESEARCH 2009; 68:128-136. [PMID: 19527915 DOI: 10.1016/j.marenvres.2009.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 04/29/2009] [Accepted: 05/07/2009] [Indexed: 05/27/2023]
Abstract
Histopathological alterations in the reproductive tissue of the female sea urchin Psammechinus miliaris after exposure to the polycyclic aromatic hydrocarbon (PAH) phenanthrene were investigated using light microscopy. Sexually mature sea urchins were exposed to 500 microg L(-1) phenanthrene for 20 days. A severe disorganisation of the acinal structure of the gonads was observed in phenanthrene-treated animals, mainly as a result of aggregates of degenerating previtellogenic oocytes. Growth and maturation of previtellogenic oocytes were inhibited, whereas there were no obvious effects on vitellogenic oocytes and mature ova. The acinal wall showed signs of fibrosis as well as dilation of the two epithelial layers. Phenanthrene severely affected the reproductive function of the sea urchins since a proper oogenesis of the ovarian tissue is very unlikely. Generally, the observed alterations are similar to histopathological changes in reproductive tissue in other invertebrates after exposure to PAHs and oil.
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Kurbacher CM, Schmidt M, Kurbacher JA, Schäfer S, Arenz PN, Nagel WJ, Reinhold U. Bevacizumab (BEV) and continuous low-dose granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with advanced solid tumors: final results of a prospective clinical trial. J Clin Oncol 2009. [DOI: 10.1200/jco.2009.27.15_suppl.e14544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e14544 Background: BEV is potent inhibitor of VEGF-mediated tumor angiogenesis. VEGF is also crucial in antineoplastic immunortolerance by blocking the generation of dendritic cells (DC). VEGF inhibition may thus result in an improved anti-cancer immune response which may be further augmented by GM-CSF, a powerful stimulator of DC generation. In a previous study, GM-CSF was able to produce clinical responses in patients (pts) suffering from refractory carcinomas (Kurbacher et al., Oncology 2005). In this trial, we investigated BEV+GM-CSF in pts with advanced solid neoplasms. Methods: 26 pts have been enrolled: epithelial ovarian cancer, n=12; breast cancer, n= 6; primary peritoneal carcinoma, n=3; hormone-refractory prostate cancer, n=2; miscellaneous, n=3. All pts have been considered refractory to or non-treatable by chemotherapy due to their baseline bone marrow and/or organ functions. Fourteen pts had previously received BEV as part of other antineoplastic regimens. BEV was applied at a fixed dose of 6 mg/kg q2w. The starting dose of GM-CSF (sargramostim) was 125 μg/d. In cases not responding and/or not achieving moderate leukocytosis (< 20 G/L), GM-CSF was increased every 4 weeks at 25 μg increments up to a maximum of 250 μg/d. Toxicity was documented according to the NCI-CTC score, responses were recorded according to the RECIST or Rustin criteria. Results: Grade (G) 3–4 hypertension was seen in 3 pts, with 1 pt experiencing cerebral stroke 6 weeks after cessation of BEV+GM-CSF. Other G3–4 toxicities were fatigue in two pts, and fever, pain, myalgia, and central nervous symptoms in either one pt. Other side-effects like injection-site reactions, proteinuria, anemia, thrombocytopenia, and constipation did not exceed G1–2. The objective response rate was 31% (1 CR, 7 PR, 10 SD, and 8 PD); the rate of pts benefiting was 69%. Eight pts failing prior BEV benefited from BEV+GM-CSF. Until today, 13 pts have died. The median time to progression is 92 days and the median overall survival is 302 days. Conclusions: BEV+GM-CSF is an active and generally well tolerated non-cytotoxic regimen in pts with advanced solid tumors. Thus, large-scaled studies of this promising treatment are warranted. No significant financial relationships to disclose.
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Zieger B, Jenny A, Tsakiris DA, Bartsch I, Sandrock K, Schubart C, Schäfer S, Busse A, Wuillemin WA. A large Swiss family with Bernard-Soulier syndrome - Correlation phenotype and genotype. Hamostaseologie 2009; 29:161-167. [PMID: 19404517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023] Open
Abstract
Bernard-Soulier syndrome (BSS) is a rare, autosomal recessive inherited bleeding disorder associated with thrombocytopenia, thrombocytopathy and giant platelets. BSS is caused by genetic alterations of the glycoprotein (GP) Ib/V/IX complex. We report on a large Swiss family of whom four family members suffer from BSS. Here, a homozygous missense mutation in position 1829 (A(R)G) of the GPIX gene constituting a N45S substitution is the cause for the bleeding symptoms. A total of 38 family members within two generations were analyzed regarding the N45S mutation by DNA sequencing and restriction fragment length polymorphism. The laboratory parameters which are characteristically for BSS such as platelet count, platelet volume and the expression of CD42a (GPIX), CD42b (GPIbalpha) and CD41 (GPIIb) were measured for all 38 individuals. The four homozygous patients showed bleeding symptoms, thrombocytopenia and giant platelets. In these patients, the expression of CD42a (GPIX), CD42b (GPIbalpha) was diminished. Interestingly, the intensity of the bleeding symptoms of the 4 homozygous family members seemed to vary although they carry the same mutation. The 24 heterozygous carriers did not differ significantly from their 10 wildtype family members regarding bleeding symptoms and laboratory analysis.
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Fleischmann L, Linck M, Burck A, Domesle C, Kempf S, Rodrigues M, Pabinger A, Pies C, Porst JP, Rotzinger H, Schäfer S, Weldle R, Fleischmann A, Enss C, Seidel GM. Physics and applications of metallic magnetic calorimeters for particle detection. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/150/1/012013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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91
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Schäfer S, Arnim AV. Einsatz von Körperbildskulpturtest und Körperbildinterview als Verlaufsinstrumente bei stationär behandelten Traumapatientinnen. Psychother Psychosom Med Psychol 2009. [DOI: 10.1055/s-0029-1208245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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92
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Schäfer S, Brüning K, Fiori W, Kiesel L, Buchweitz O. Wird die operative Therapie der Endometriose im aktuellen DRG-System sachgerecht abgebildet? Geburtshilfe Frauenheilkd 2008. [DOI: 10.1055/s-2008-1039047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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93
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Meyer S, von Mach MA, Ivan D, Schäfer S, Habbe N, Kann B, Kann PH. Color-coded duplex endoscopic ultrasound of the adrenals. J Endocrinol Invest 2008; 31:882-7. [PMID: 19092293 DOI: 10.1007/bf03346436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Imaging of the adrenals by endoscopic ultrasound (EUS) is a valuable technique for detection and localization of adrenal lesions, but endosonomorphological tumor distinction remains difficult. In this single-center study, the amount of blood flow in common adrenal lesions, such as adrenal adenomas, adrenal hyperplasia, and pheochromocytomas, was visualized by color-coded duplex EUS (CD-EUS) and was retrospectively analysed. Therefore, we reviewed our EUS database to evaluate and correlate the perfusion patterns of common adrenal lesions with histologically confirmed diagnosis, possible malignancy, and endosonomorphological features such as echogeneity, echostructure, and tumor size. CD-EUS was performed using an endosonoscope Pentax FG 32 UA with a longitudinal 7.5 MHz sector array and Hitachi EUB 525 ultrasound system. In 38 consecutive patients (male=19; female=19; age: mean 53+/-16 yr SD), perfusion patterns of 46 histologically confirmed adrenal, para- or extra-adrenal lesions of adrenal origin (adenoma: no.=20; nodular hyperplasia: no.=11; pheochromocytoma: no.=15; diameter 26+/-15 mm, range 6-70 mm) were analyzed and classified semiquantitatively as "not" (no.=24), "slightly" (no.=12), "moderately" (no.=4) or "highly" (no.=6) hypervascularized. Compared to adenomas (p=0.003) and nodular hyperplasia (p=0.047), pheochromocytomas showed a significantly higher grade of perfusion. There was no relationship between perfusion patterns and localization of pheochromocytomas (adrenal: 8; paraadrenal: 3; extra-adrenal: 4). Vascularization was not statistically associated with tumor echogeneity, echostructure, malignancy or tumor size. CD-EUS is an additional tool for adrenal endosonographic tumor distinction and seems to improve the endosonographic detection of pheochromocytomas by visualization of hypervascularization. As an overlap of perfusion patterns exists, CD-EUS findings must be interpreted in the context of clinical, laboratory and chemical results.
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Steinhard J, Schmitz R, Heinig J, Schäfer S, Kiesel L. Detektion der atrialen Kontraktion des fetalen Herzens mit Tissue Doppler Imaging (TDI). Geburtshilfe Frauenheilkd 2008. [DOI: 10.1055/s-0028-1088591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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95
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Hollauer A, Langolf OA, Selten A, Fuhr N, Schäfer S, Ebert AD. Laparoscopic stripping of benigne ovarian cysts without bi-coagulation or sutures using a gelantin-thrombin matrix (FloSeal) – First report of a promising technique. Geburtshilfe Frauenheilkd 2008. [DOI: 10.1055/s-0028-1088740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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96
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Kurbacher CM, Schäfer S, Wessling G, Kurbacher JA, Arenz PN, Schmidt M. Bevacizumab and granulocyte-macrophage colony-stimulating factor in pretreated patients with metastatic solid malignancies. Geburtshilfe Frauenheilkd 2008. [DOI: 10.1055/s-0028-1088676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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97
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Steinhard J, Schmitz R, Schäfer S, Heinig J, Kiesel L. Speckle tracking imaging (STI) erlaubt die 3D-Darstellung der fetalen rechtsventrikulären myokardialen Kontraktion (Strain). Geburtshilfe Frauenheilkd 2008. [DOI: 10.1055/s-0028-1088954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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98
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Schäfer S, Eick S, Hofmann B, Dufaux T, Stockmann R, Wrobel G, Offenhäusser A, Ingebrandt S. Time-dependent observation of individual cellular binding events to field-effect transistors. Biosens Bioelectron 2008; 24:1201-8. [PMID: 18692383 DOI: 10.1016/j.bios.2008.07.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 07/04/2008] [Accepted: 07/07/2008] [Indexed: 10/21/2022]
Abstract
Electrolyte-gate field-effect transistors (EG-FETs) gained continuously more importance in the field of bioelectronics. The reasons for this are the intrinsic properties of these FETs. Binding of analysts or changes in the electrolyte composition are leading to variations of the drain-source current. Furthermore, due to the signal amplification upon voltage-to-current conversion even small extracellular signals can be detected. Here we report about impedance spectroscopy with an FET array to characterize passive components of a cell attached to the transistor gate. We developed a 16-channel readout system, which provides a simultaneous, lock-in based readout. A test signal of known amplitude and phase was applied via the reference electrode. We monitored the electronic transfer function of the FETs with the attached cell. The resulting frequency spectrum was used to investigate the surface adhesion of individual HEK293 cells. We applied different chemical treatments with either the serinpeptidase trypsin or the ionophor amphotericin B (AmpB). Binding studies can be realized by a time-dependent readout of the lock-in amplifier at a constant frequency. We observed cell detachment upon trypsin activity as well as membrane decomposition induced by AmpB. The results were interpreted in terms of an equivalent electrical circuit model of the complete system. The presented method could in future be applied to monitor more relevant biomedical manipulations of individual cells. Due to the utilization of the silicon technology, our method could be easily up-scaled to many output channels for high throughput pharmacological screening.
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Schmitz R, Schmitter M, Schäfer S, Kiesel L, Klockenbusch W, Steinhard J. Ultraschall im 3. Trimenon. Geburtshilfe Frauenheilkd 2008. [DOI: 10.1055/s-2008-1038755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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100
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Schäfer S. Die Aufteilung der Ia-Fasern de-efferenzierter Katzen-Muskelspindeln in zwei Gruppen. KLIN NEUROPHYSIOL 2008. [DOI: 10.1055/s-2008-1060721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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