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  • 1
    Language: English
    In: Environmental Science and Pollution Research, 2008, Vol.15(1), pp.75-83
    Description: Byline: Robert Kase (1), Peter-D. Hansen (2), Birgit Fischer (2), Werner Manz (1), Peter Heininger (1), Georg Reifferscheid (1) Keywords: Anti-estrogenic substances; aquatic environment; endocrine disrupting chemicals (EDC); Enzyme-Linked Receptor Assay (ELRA); E-Screen; estrogenicity; salinity tolerance; Yeast Estrogen Screen (YES) Abstract: Goal, Scope and Background Exogenic endocrine-active substances are also called 'Endocrine Disrupting Chemicals' (EDC). They imitate or hinder the function of natural endogenic hormones or disturb the synthesis or the metabolism of hormones or of hormone receptors. The Enzyme-Linked Receptor Assay (ELRA) can detect estrogenic and anti-estrogenic effects at the level of receptor binding and is a useful tool for the integrative detection of contaminant effects. Although the test system has been used repeatedly in sediment assessments, the questions have remained concerning how it responds to variations in the physico-chemical matrix. For some bioassays, the salinity of the sample is a critical factor. This is especially relevant when testing wastewater samples or when sediment-associated samples in the tidal reaches of rivers are tested. Sediments in the tidal reaches of rivers change their salinity several times a day. Against this background, it would be beneficial to have a test procedure of known salinity tolerance. On account of this, the salinity tolerance of the ELRA was tested, assessed with reference substances at several salinity levels, and compared with the E-Screen method and a Yeast Estrogen Screen (YES), which are also frequently applied in environmental testing. The aim of this paper was to explore when the salinity limits within these test procedures are applicable. The trials should reveal the working range to be expected, characterize the salinity-dependent variations in sensitivity of the test, and provide options for methodological adjustments to improve the stability against increased salinity. Methods The ELRA was carried out with the human Estrogen Receptor [alpha]. (ER) using the same principle like a competitive immunoassay based on ligand-protein interaction. However, an essential difference is the use of a physiologically relevant receptor instead of an antibody as a linking protein. The ELRA measures the competition of sample estrogens and anti-estrogens against estradiol supplied as a BSA-coating conjugate for the binding site of dissolved ER. Estradiol or xeno-estrogen binding is quantified by a biotynilated anti-ER antibody and the subsequent measurement of peroxidase activity by a streptavidin-POD-biotin complex. The E-Screen was performed with the human breast cancer cell line MCF-7, which expresses the estrogen receptor constitutively. Cell proliferation depends on binding of estrogens or xeno-estrogens with the receptor. After incubation, estrogen-dependent cell growth was measured by sulforhodamin B staining. The YES was performed with a recombinant yeast strain, transfected with a receptor and a reporter plasmid bearing the estrogen receptor and a vitellogenin gene fused with the reporter gene lacZ. Estrogen or xeno-estrogen-dependent gene induction was measured indirectly by LacZ activity. The salinity levels were simulated in varying concentrations with NaCl from 0 to 40[per thousand] or Artificial Sea Water (ASW) from 0 to 32[per thousand]. Results The study characterized the factor 'salinity' for the prospective application fields of the ELRA. With reference substances such as 17-[beta]-estradiol, the ELRA showed classical sigmoidal concentration-effect relations in a range from 0.05 to 100 ug/l under physiological conditions. After a methodological adjustment to compensate decreasing receptor-binding affinity of estrogens and xeno-estrogens at higher salinity levels. the ELRA became applicable under salinity conditions up to concentrations of 20.5[per thousand]. In tests, the ELRA reached under the influence of salinity a mean limit of detection of 0.062 [beta]g/l 17-[beta]-estradiol. The mean relative inter-test error was around 11%. Above concentrations of 20.5[per thousand] there is a risk of false negative assessment. Compared with the E-Screen method using the MCF7 cell line and the yeast estrogen test system (YES), the ELRA shows a lower sensitivity to 17-[beta]-estradiol. In the E-Screen, the cell proliferation was strongly reduced by sodium chloride induced cytotoxicity. In comparison with the E-Screen, the salinity tolerance of the YES and YAS methods is significantly higher. Discussion Despite adaption, total salinity tolerance could not be achieved with the ELRA. Freshwater samples were generally appraisable. Higher salinity levels above 20.5[per thousand] would tend towards false negative results. The low inter-test error of 11% makes the ELRA suitable for the detection of estrogenic and anti-estrogenic potentials of single substances, substance mixtures, and of environmental samples. Conclusions The ELRA is very fast and reproducible, it can be used for high-throughput screening in a microplate format at low cost, it is robust to microbial contamination, and is less susceptible to cytotoxic interferences than cell culture methods. Recommendations and Perspectives In their established form, the YES and the E-Screen methods are not applicable for liquid phase testing at higher salinity conditions. The salinity-adapted test version of the ELRA described here shows a broader working range for samples. Native water samples of more or less brackish origin or high-salinity effluent samples are testable. Results of tests with sediment associated samples of different salinity will be subject of a forthcoming publication. Author Affiliation: (1) German Federal Institute of Hydrology, Am Mainzer Tor 1, 56068, Koblenz, Germany (2) Department of Ecotoxicology, Technical University of Berlin, Franklinstrasse 29, 10587, Berlin, Germany Article History: Registration Date: 04/06/2007 Received Date: 07/08/2006 Accepted Date: 13/06/2007 Online Date: 13/06/2007 Article note: ESS-Submission Editor: Dr. Jan Schwarzbauer (schwarzbauer@lek.rwth-aachen.de)
    Keywords: Anti-estrogenic substances ; aquatic environment ; endocrine disrupting chemicals (EDC) ; Enzyme-Linked Receptor Assay (ELRA) ; E-Screen ; estrogenicity ; salinity tolerance ; Yeast Estrogen Screen (YES)
    ISSN: 0944-1344
    E-ISSN: 1614-7499
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  • 2
    Language: English
    In: PLoS ONE, 2013, Vol. 8(10)
    Description: The estuary of the River Elbe between Hamburg and the North Sea (Germany) is a sink for contaminated sediment and suspended particulate matter (SPM). One major concern is the effect of human activities on the hydrodynamics, particularlythe intensive dredging activities in this area that may result in remobilization of sediment-bound pollutants. The aim of this study was to identify pollutants contributing to the toxicological risk associated with re-suspension of sediments in the Elbe Estuary by use of an effect-directed analysis that combines chemical and biological analyses in with specific fractionation techniques. Sediments were collected from sites along the Elbe Estuary and a site from a small harbor basin of the Elbe Estuary that is known to be polluted. The sixteen priority EPA-PAHs were quantified in organic extracts of sediments. In addition, dioxin equivalents of sediments were investigated by use of the 7-ethoxyresorufin O-deethylase assay with RTL-W1 cells and the Ah receptor-mediated luciferase transactivation assay with H4IIE-luc cells. Quantification of the 16 priorityPAHs revealed that sediments were moderately contaminated at all of the sites in the Elbe River Estuary (,0.02–0.906 mg/gdw). Sediments contained relatively small concentrations of dioxin equivalents (Bio-TEQ) with concentrations ranging from15.5 to 322 pg/g dw, which were significantly correlated with dioxin equivalents calculated based on toxicity referencevalues and concentrations of PAH. The concentration of Bio-TEQ at the reference site exceeded 200,000 pg/g dw. In apotency balance the 16 PAHs explained between 47 and 118% of the Bio-TEQ in the luciferase assay, which can be explained by the constant input of PAHs bound to SPM from the upper course of the Elbe River into its estuary. Successful identification of a significant portion of dioxin-like activity to priority PAHs in complex environmental samples such assediments has rarely been reported.
    Keywords: Natural Sciences ; Earth And Related Environmental Sciences ; Environmental Sciences ; Naturvetenskap ; Geovetenskap Och Miljövetenskap ; Miljövetenskap ; Enviromental Science ; Miljövetenskap
    ISSN: 1932-6203
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  • 3
    Language: English
    In: Clinical chemistry, February 2002, Vol.48(2), pp.315-22
    Description: In children and adolescents, markers of bone and collagen metabolism reflect the dynamics of skeletal growth and development. The aim of this study was to assess the relationship of the urinary collagen markers deoxypyridinoline (DPD) and hydroxylysine (Hyl) and its glycosides [galactosyl-Hyl (Gal-Hyl) and glucosyl-Gal-Hyl] with growth. Urine samples from 240 apparently healthy children and adolescents (6-19 years; 124 girls) and from 51 prepubertal children with growth hormone (GH) deficiency (3-14 years; 14 girls) were analyzed. Urinary Hyl and its glycosides were quantified by HPLC, and DPD was assessed by chemiluminescence assay. Urinary concentrations of all markers were related to urinary creatinine. Multiple regression analysis revealed that only age and height velocity were independently associated with these markers in healthy children. In GH-deficient patients, the urinary excretion of both analytes after 4 weeks of GH therapy correlated significantly with the height increase during the first treatment year (r = 0.79 for Gal-Hyl; r = 0.70 for DPD; P 〈0.001 each). In a multivariate linear regression model using Gal-Hyl concentrations at 4 weeks, baseline concentrations of insulin-like growth factor 1 and height velocity after 3 months accounted for 80% of the variability in height gain during the first treatment year. A model using DPD concentrations at 4 weeks, in place of Gal-Hyl concentrations, as well as baseline concentrations of insulin-like growth factor 1 and height velocity after 3 months accounted for 83% of the variability. These urinary bone and collagen markers give some early indication of growth response, but the prediction of an individual marker is too imprecise to serve as a basis for clinical decisions. Markers of bone and collagen metabolism might be more useful as components of multivariate growth prediction models.
    Keywords: Growth ; Amino Acids -- Urine ; Collagen -- Urine ; Dwarfism, Pituitary -- Diagnosis ; Glycosides -- Urine ; Hydroxylysine -- Urine
    ISSN: 0009-9147
    E-ISSN: 15308561
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  • 4
    Language: English
    In: PLoS ONE, 2009, Vol.4(10), p.e7517
    Description: There is an urgent need for new drugs against influenza type A and B viruses due to incomplete protection by vaccines and the emergence of resistance to current antivirals. The influenza virus polymerase complex, consisting of the PB1, PB2 and PA subunits, represents a promising target for the development of new drugs. We have previously demonstrated the feasibility of targeting the protein-protein interaction domain between the PB1 and PA subunits of the polymerase complex of influenza A virus using a small peptide derived from the PA-binding domain of PB1. However, this influenza A virus-derived peptide did not affect influenza B virus polymerase activity. Here we report that the PA-binding domain of the polymerase subunit PB1 of influenza A and B viruses is highly conserved and that mutual amino acid exchange shows that they cannot be functionally exchanged with each other. Based on phylogenetic analysis and a novel biochemical ELISA-based screening approach, we were able to identify an influenza A-derived peptide with a single influenza B-specific amino acid substitution which efficiently binds to PA of both virus types. This dual-binding peptide blocked the viral polymerase activity and growth of both virus types. Our findings provide proof of principle that protein-protein interaction inhibitors can be generated against influenza A and B viruses. Furthermore, this dual-binding peptide, combined with our novel screening method, is a promising platform to identify new antiviral lead compounds.
    Keywords: Research Article ; Biochemistry -- Drug Discovery ; Virology -- Antivirals, Including Modes Of Action And Resistance ; Virology -- New Therapies, Including Antivirals And Immunotherapy ; Infectious Diseases -- Viral Infections
    E-ISSN: 1932-6203
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  • 5
    Language: English
    In: American Heart Journal, 1994, Vol.127(4), pp.978-984
    Description: Es ist wichtig, die potentiellen Wechselwirkungen zwischen dem implantierbaren Kardioverter-Defibrillator (ICD) und antiarrhythmischer Therapie in Patienten zu verstehen, die als Adjunkt zur ICD-Therapie pharmakologisch behandelt werden. In der 101 Patienten umfassenden Kohortenstudie der Autoren wurden in 61 % der Patienten im Rahmen der Langzeittherapie aus folgenden Gründen Antiarrhythmika verschrieben: Unterdrückung von ventrikulären Tachykardien bzw. ventrikulären Fibrillationen (50 %), die Frequenz ventrikulärer Tachykardien zu erniedrigen (19 %), supraventrikulären Tachykardien vorzubeugen (21 %) und aus anderen Gründen (10 %). Der wichtigste Punkt ist der potentielle Einfluß von antiarrhythmischen Medikamenten auf die Defibrillationsschwelle (DFT). In Tierstudien erhöhte z.B. Lidocain in einer dosisabhängigen Weise die DFT. Quinidin, Procainamid, Propafenon und Flecainid hatten keinen Einfluß auf die DFT bzw. führten nur in wenigen Fällen zu einer geringen Zunahme. Sotalol verringerte bei interner Defibrillation die benötigte Energie. In einer prospektiven Studie konnten die Autoren belegen, daß der Einsatz von Amiodaron die DFT signifikant von 14,1 + 3,0 auf 20,9 + 5,4 J, p 〈 0.001 erhöhte (400 mg/Tag); Mexiletinin hatte keinen Einfluß (720 mg/Tag). Als Fazit schließen die Autoren, daß vor einer Gabe von antiarrhythmischen Pharmaka die DFT bzw. deren Sicherheitszone bekannt sein muß, wenn Patienten behandelt werden sollen, die einen ICD haben. Liegt nur eine geringe Sicherheitszone vor, so soll nach Beginn der Therapie die DFT neu ermittelt werden.
    Keywords: Medicine
    ISSN: 0002-8703
    E-ISSN: 1097-6744
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  • 6
    In: Circulation, 1992, Vol.86(4), pp.1217-1222
    Description: BACKGROUND: Shock delivery of an implantable defibrillator may cause a change in the amplitude of endocardial electrograms and impair the detection of ventricular fibrillation. Thus, the effects of shock discharges on the amplitude of endocardial electrograms were evaluated in five patients undergoing implantation of a cardioverter-defibrillator in combination with a new nonthoracotomy lead system METHODS AND RESULTS: At implant, bipolar endocardial electrograms were recorded before each shock application, during ventricular fibrillation, during redetection of ventricular fibrillation in case the applied shock was ineffective, and at intervals of 5, 10, 20, 30, 60, and 120 seconds after each shock delivery. The amplitude of the endocardial electrograms decreased from 10.5±3.8 mV during sinus rhythm to 6.3±1.9 mV during initial ventricular fibrillation and declined to 2.2±1.3 mV during redetection of ventricular fibrillation. After successful termination, the following bipolar electrograms could be obtained at the predetermined intervals: 1.9±1.2 mV, 3.1±1.8 mV, 4.5±1.9 mV, 6.5±2.9 mV, 9.5±3.3 mV, and 10.4±3.8 mV. At predischarge testing, failure of redetection of ventricular fibrillation could be documented in two patients, requiring rescue external defibrillation in both cases to restore sinus rhythm. CONCLUSIONS: These findings demonstrate that the implantable cardioverter-defibrillator did not ensure reliable redetection of ventricular fibrillation in patients using the implanted nonthoracotomy lead system. Thus, the potential risk of sudden cardiac death may persist in these patients despite defibrillator therapy.
    Keywords: Medicine ; Anatomy & Physiology;
    ISSN: 0009-7322
    E-ISSN: 15244539
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  • 7
    In: Pacing and Clinical Electrophysiology, April 1992, Vol.15(4), pp.645-648
    Description: The implantable cardioverter defibrillator is designed to prevent sudden cardiac death from ventricular tachyarrhythmias. The long-term efficacy of the implantable cardioverter defibrillator has been demonstrated by several investigators. Up to 70 % of the patients who receive an implantable cardioverter defibrillator will also be maintained on concomitant antiarrhythmic drug treatment for a variety of reasons including suppression of non-sustained ventricular tachycardia, elimination of supraventricular tachyarrhythmias, and decrease of the frequency of sustained ventricular events. Since various antiarrhythmic drugs have been reported to alter defibrillation threshold. It is a major issue to obtain more information about the chronic defibrillation threshold in patients treated by the implantable cardioverter defibrillator. This publication reports details.
    Keywords: Elektrotherapie ; Elektrische Stimulation ; Defibrillator ; Implantation (Chirurgie) ; Kenndaten ; Arzneimittelwechselwirkung ; Arzneimittel ; Reizwahrnehmung ; Tachykardie ; Ventrikel (Herzkammer) ; Medicine;
    ISSN: 0147-8389
    E-ISSN: 1540-8159
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  • 8
    Language: English
    In: American Heart Journal, 1994, Vol.127(4), pp.1179-1184
    Description: Clinical experience suggests that the implantable cardioverter defibrillator (ICD) can reduce sudden cardiac death and total mortality in patients with malignant ventricular arrhythmia who meet the selection criteria for implantation. In addition to surgical problems, patients are faced with psychological and social adjustments. Patient acceptance for such therapy is marked by perceived concerns regarding device discharge, life-style alterations, and complications. We included 57 patients with ICDs in a study of their acceptance of the device. Results of a specially designed questionnaire (state-trait personality inventory) showed that 47 of 57 patients felt that their symptoms improved with the ICD system, 32 were constantly aware of the device, and 24 patients acclimated to the ICD system within less than 2 months. With respect to the need for battery replacement, only 27 patients requested a repeat electrophysiologic evaluation, 20 patients stated fear of ICD discharges, 12 patients revealed physical discomfort from the device, and limited quality of life occurred in eight patients. Fifty-five of 57 patients answered that it was worth having an ICD device implanted, 30 (53%) patients returned to active life, and 56 (98%) would advise another patient to have an ICD implantation if necessary. In conclusion, in general, the acceptance of the ICD as a tool for management of life-threatening ventricular tachyarrhythmias is very high. Quality of life and patient acceptance are important criteria for successful ICD therapy in addition to the improved survival rate.
    Keywords: Medicine
    ISSN: 0002-8703
    E-ISSN: 1097-6744
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  • 9
    In: Pacing and Clinical Electrophysiology, September 1993, Vol.16(9), pp.1815-1821
    Description: Besides surgical problems, recipierifs of implantable cardioverter defibrillators (ICDs) are faced with psychological and social adjustments. Successful ICD therapy is influenced by the patients’ perceived concerns regarding device, discharge, changes in life style, and complications. In order to assess patients’ acceptance of the ICD, the psychological profile of 57 consecutive patients was evaluated using a specifically designed questionnaire and the State Trait Anxiety Inventory (STAI). The results showed that 20 patients staled fear of ICD discharge, 12 patients revealed physical discomfort due to the device, and limited quality‐of‐life occurred in 8 patients. Fifty‐five of 57 patients answered that it was worth having an ICD device implanted, 30 (53%) patients returned to active life, and 56 (98%) would advise another patient to undergo implantation if necessary. Overall, there was only a slight, but insignificant, decrease in the level of anxiety within the total patient population after ICD implantation. However, a comparison of two subgroups indicated that the state of anxiety was significantly higher in patients 5 shocks versus those 〉 50 years of age and having experienced 〈 5 shocks. In general, the acceptance of the ICD as a tool in managing life‐threatening ventricular tachyarrhythmias is high. Besides the increased survival rate, quality‐of‐life and patient acceptance are important criteria for successful ICD therapy.
    Keywords: Implantable Cardioverter Defibrillator Icd ; Patient Acceptance ; Icd Psychological And Social Aspects
    ISSN: 0147-8389
    E-ISSN: 1540-8159
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  • 10
    In: Pacing and Clinical Electrophysiology, April 1993, Vol.16(4), pp.778-788
    Description: In a prospective study the efficacy of amiodarone in combinalion with the three Class I drugs mexiletine, fiecainide, orencainide was evaluated consecutively in 12 patients with recurrent venlriculav tachycardias (VT) by programmed stimulation. None of the tested drug combinations suppressed induction of sustained VT. The combination of amiodarone with Class IC drugs fJecainide and encainide prolonged the cycle length of VT significantly, whereas the combination with mexiletine did not hove the same degree of slowing on the VT cycle length. Several proarrhythmic effects occurred during the combination therapy with encainide: (1) frequent, spontaneous recurrences of hemodynamically well tolerated VT in four patients; (2) enhanced inducihilily of VT in three patients; (3) impaired termination of VT in three patients. Though a marked increase in QRS and QTc intervals was observed by combined treatment with encainide, no significant correlation could be established between aggravation of arrhythmia and plasma levels of encainide, degree of QRS widening, JT or QTc prolongation. The only predictor for the occurrence of proarrhythmic events was found in left ventricular ejection fraction. These findings suggest that in patients refractory to amiodarone alone or a combination with mexiletine, the combined treatment of amiodarone with other Class IC drugs prolongs the VT cycle length but does not suppress induction of VT during programmed stimulation. Combination therapy of amiodarone with encainide was associated with a high incidence of proarrhythmic effects.
    Keywords: Proarrhythmic Effects ; Antiarrhythmic Combination ; Amiodarone ; Mexiletine ; Flecainide ; Encainide
    ISSN: 0147-8389
    E-ISSN: 1540-8159
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