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Ritter D, Schwarz K, Knebel J, Hansen T, Zifle A, Fuchs A, Fautz R. P13-13 Development of a non-target strategy for evaluation of potential biological effects of inhalable aerosols generated during purposeful room conditioning using an in vitro inhalation model. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Nowak N, Sonnenschein N, Hansen T, Ritter D, Blümlein K, Escher S, Schwarz K. P17-10 Design and application of a physiologically based kinetic (PBK) model for uptake of airborne particulates. Toxicol Lett 2022. [DOI: 10.1016/j.toxlet.2022.07.620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Luettges K, Bode M, Thiele A, Ritter D, Klopfleisch R, Kappert K, Foryst-Ludwig A, Kolkhof P, Wenzel U, Kintscher U. Finerenone reduces renal RORgt gd T-Cells and protects against cardiorenal damage. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Chronic activation of the mineralocorticoid receptor (MR) through the agonist aldosterone leads to pathological processes like inflammation, fibrosis, and increased blood pressure. Therefore, MR antagonists (MRA) belong to guideline-based therapy for hypertension and heart failure with reduced ejection fraction. The nonsteroidal, selective MRA finerenone (FIN) induces distinct pharmacological actions when compared to steroidal MRAs including less adverse effects and improved efficacy (e.g. anti-fibrosis). In this study, we investigated the effects of FIN in a deoxycorticosterone acetate (DOCA)-salt model which induces an increase of blood pressure and end organ damage including hypertrophy, fibrosis, and inflammatory cell infiltration in heart and kidney.
Male C57BL6/J mice were either uni-nephrectomized in addition to DOCA-pellet application (2.4mg/d) and 0.9% NaCl in the drinking water (DOCA/UNX) or received a sham operation. One week prior to the surgery, oral treatment with FIN (10mg/kg/d) or vehicle (VEH) started and lasted throughout the experiment. Five weeks after the procedure, final examinations including blood pressure (BP) measurement, urine analysis, speckle-tracking echocardiography (STE), and FACS analysis of the heart and kidney were performed.
BP was significantly reduced by FIN treatment. FACS analysis revealed a notable immune response due to DOCA/ UNX exposure. Especially infiltrating renal RORγt γδ T-Cells were upregulated, which was significantly ameliorated by the FIN-treatment. This was accompanied by an improvement of kidney function shown by a reduction of the urinary albumin/creatinine ratio in FIN-treated mice. In the heart, FIN reduced DOCA/ UNX-induced cardiac hypertrophy, cardiac fibrosis and led to an improvement of the global longitudinal strain (GLS) in the STE-analysis. Cardiac actions of FIN were not associated with a regulation of cardiac RORγt γδ T-Cells.
The present study shows cardiac and renal protective effects of FIN in a DOCA/UNX model. The cardiorenal protection was accompanied by a reduction of renal RORγt γδ T-Cells. Anti-inflammatory actions of FIN may provide a potential mechanism of its clinical efficacy recently observed in clinical trials.
Funding Acknowledgement
Type of funding sources: Private company. Main funding source(s): Bayer AG
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Affiliation(s)
- K Luettges
- Charite Universitatsmedizin Berlin, Berlin, Germany
| | - M Bode
- University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - A Thiele
- Charite Universitatsmedizin Berlin, Berlin, Germany
| | - D Ritter
- Charite Universitatsmedizin Berlin, Berlin, Germany
| | | | - K Kappert
- Charite Universitatsmedizin Berlin, Berlin, Germany
| | | | | | - U Wenzel
- University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - U Kintscher
- Charite Universitatsmedizin Berlin, Berlin, Germany
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Jenkins MC, Parker CC, O'Brien CN, Ritter D. Viable Eimeria oocysts in poultry house litter at the time of chick placement. Poult Sci 2019; 98:3176-3180. [PMID: 30953077 DOI: 10.3382/ps/pez147] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 03/11/2019] [Indexed: 11/20/2022] Open
Abstract
The purpose of this study was to determine if Eimeria oocysts recovered from litter at the time of chick placement in commercial broiler houses contained oocysts that were infectious for chickens. Over 100 litter samples were collected from 30 poultry farms representing a total of 60 different broiler houses with 9 houses sampled more than once over 1.5 yr. The samples were collected just before the placement of newly hatched chicks and after an anticoccidial drug (ACD) or Eimeria vaccine (VAC) program, and processed for counting oocysts followed by Eimeria species determination using ITS1 PCR. Broiler chicks were inoculated with recovered Eimeria oocysts to determine if the litter oocysts were viable and capable of causing patent infection. At placement, E. maxima (Emax) oocysts were detected in 70 of 75 houses after ACD program and 46 of 47 houses after VAC program. Eimeria acervulina, E. praecox, and/or E. tenella (Eapt) were detected in 75 of 75 houses after ACD program and 47 of 47 houses after VAC program. Viability testing revealed that 33.0% of broiler houses contained viable Emax oocysts, while 46.9% contained viable Eapt oocysts. During VAC programs, the concentration of Emax oocysts at placement and the total number of Emax oocysts shed by chickens in viability studies showed a very strong correlation (r = 0.83). Likewise, during ACD programs, the concentration of Eapt oocysts at placement and the total number of Eapt oocysts shed by chickens in the viability study showed a strong correlation (r = 0.62). In general, Eimeria oocyst levels at placement and number of viable oocysts shed by chickens in the viability study were similar among houses on the same farm. However, the number of Eimeria oocysts shed in the viability studies was considerably less than expected based on the number of oocysts given. These data suggest that nearly 100% of all poultry houses contain Emax and Eapt oocysts at placement with 30 to 50% of the houses containing viable Eimeria oocysts, thus possibly representing a source of the protozoa to newly hatched chicks.
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Affiliation(s)
- M C Jenkins
- Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, NEA, ARS, USDA, Building 1040, BARC-EAST, Beltsville, MD 20705, USA
| | - C C Parker
- Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, NEA, ARS, USDA, Building 1040, BARC-EAST, Beltsville, MD 20705, USA
| | - C N O'Brien
- Animal Parasitic Diseases Laboratory, Beltsville Agricultural Research Center, NEA, ARS, USDA, Building 1040, BARC-EAST, Beltsville, MD 20705, USA
| | - D Ritter
- Mountaire Farms, Inc., Millsboro, DE 19966, USA
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Brodbeck C, Wolf K, Ritter D, Knebel J. Use of Computational Fluid Dynamics for optimization of cell-based in vitro methods in inhalation research. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.06.1550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Obernolte H, Ritter D, Knebel J, Braubach P, Jonigk D, Warnecke G, Krüger M, Fieguth HG, Pfennig O, Braun A, Sewald K. Cigarette Smoke and Cigarette Smoke Condensate Induce Inflammation and Cytotoxicity in Precision-Cut Lung Slices (PCLS). Pneumologie 2016. [DOI: 10.1055/s-0036-1584646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Pfennig A, Conell J, Ritter P, Ritter D, Severus E, Meyer TD, Hautzinger M, Wolff J, Godemann F, Reif A, Bauer M. Leitliniengerechte psychiatrisch-psychotherapeutische Behandlung bei bipolaren Störungen. Nervenarzt 2016; 88:222-233. [PMID: 27220643 DOI: 10.1007/s00115-016-0083-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Yalon E, Karpov I, Karpov V, Riess I, Kalaev D, Ritter D. Detection of the insulating gap and conductive filament growth direction in resistive memories. Nanoscale 2015; 7:15434-15441. [PMID: 26335720 DOI: 10.1039/c5nr03314d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Filament growth is a key aspect in the operation of bipolar resistive random access memory (RRAM) devices, yet there are conflicting reports in the literature on the direction of growth of conductive filaments in valence change RRAM devices. We report here that an insulating gap between the filament and the semiconductor electrode can be detected by the metal-insulator-semiconductor bipolar transistor structure, and thus provide information on the filament growth direction. Using this technique, we show how voltage polarity and electrode chemistry control the filament growth direction during electro-forming. The experimental results and the nature of a gap between the filament and an electrode are discussed in light of possible models of filament formation.
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Affiliation(s)
- E Yalon
- Electrical Engineering Department, Technion - Israel Institute of Technology, Haifa 32000, Israel.
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Ritter D, Knebel J. Acute toxicity testing of inhalable/gaseous compounds by cell-based methods in vitro – Application to volatile organic compounds. Toxicol Lett 2015. [DOI: 10.1016/j.toxlet.2015.08.517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Obernolte H, Konzok S, Ritter D, Knebel J, Braubach P, Jonigk D, Braun A, Sewald K. Cigarette smoke condensate and cigarette smoke induce cytotoxicity and inflammation in human and rodent Precision-Cut Lung Slices of different species. Pneumologie 2015. [DOI: 10.1055/s-0035-1556609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Deplanque G, Demarchi M, Hebbar M, Flynn P, Melichar B, Atkins J, Nowara E, Moyé L, Piquemal D, Ritter D, Dubreuil P, Mansfield CD, Acin Y, Moussy A, Hermine O, Hammel P. A randomized, placebo-controlled phase III trial of masitinib plus gemcitabine in the treatment of advanced pancreatic cancer. Ann Oncol 2015; 26:1194-1200. [PMID: 25858497 PMCID: PMC4516046 DOI: 10.1093/annonc/mdv133] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/05/2015] [Accepted: 02/18/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Masitinib is a selective oral tyrosine-kinase inhibitor. The efficacy and safety of masitinib combined with gemcitabine was compared against single-agent gemcitabine in patients with advanced pancreatic ductal adenocarcinoma (PDAC). PATIENTS AND METHODS Patients with inoperable, chemotherapy-naïve, PDAC were randomized (1 : 1) to receive gemcitabine (1000 mg/m(2)) in combination with either masitinib (9 mg/kg/day) or a placebo. The primary endpoint was overall survival (OS) in the modified intent-to-treat population. Secondary OS analyses aimed to characterize subgroups with poor survival while receiving single-agent gemcitabine with subsequent evaluation of masitinib therapeutic benefit. These prospectively declared subgroups were based on pharmacogenomic data or a baseline characteristic. RESULTS Three hundred and fifty-three patients were randomly assigned to receive either masitinib plus gemcitabine (N = 175) or placebo plus gemcitabine (N = 178). Median OS was similar between treatment-arms for the overall population, at respectively, 7.7 and 7.1 months, with a hazard ratio (HR) of 0.89 (95% CI [0.70; 1.13]. Secondary analyses identified two subgroups having a significantly poor survival rate when receiving single-agent gemcitabine; one defined by an overexpression of acyl-CoA oxidase-1 (ACOX1) in blood, and another via a baseline pain intensity threshold (VAS > 20 mm). These subgroups represent a critical unmet medical need as evidenced from median OS of 5.5 months in patients receiving single-agent gemcitabine, and comprise an estimated 63% of patients. A significant treatment effect was observed in these subgroups for masitinib with median OS of 11.7 months in the 'ACOX1' subgroup [HR = 0.23 (0.10; 0.51), P = 0.001], and 8.0 months in the 'pain' subgroup [HR = 0.62 (0.43; 0.89), P = 0.012]. Despite an increased toxicity of the combination as compared with single-agent gemcitabine, side-effects remained manageable. CONCLUSIONS The present data warrant initiation of a confirmatory study that may support the use of masitinib plus gemcitabine for treatment of PDAC patients with overexpression of ACOX1 or baseline pain (VAS > 20mm). Masitinib's effect in these subgroups is also supported by biological plausibility and evidence of internal clinical validation. TRIAL REGISTRATION ClinicalTrials.gov:NCT00789633.
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Affiliation(s)
- G Deplanque
- Department of Medical Oncology, Saint Joseph Hospital, Paris.
| | - M Demarchi
- Department of Medical Oncology, University Hospital of Besançon, Besançon
| | - M Hebbar
- Department of Medical Oncology, University Hospital, Lille, France
| | - P Flynn
- Metro-Minnesota Community Clinical Oncology Program, Park Nicollet Institute, Minneapolis, USA
| | - B Melichar
- Department of Oncology, Palacký University Medical School & Teaching Hospital, Olomouc, Czech Republic
| | - J Atkins
- Southeastern Medical Oncology Center, Goldsboro, USA
| | - E Nowara
- Department of Clinical and Experimental Oncology, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice, Poland
| | - L Moyé
- Department of Biostatistics, University of Texas School of Public Health, Houston, USA
| | - D Piquemal
- Clinical Development, Acobiom, Montpellier
| | - D Ritter
- Clinical Development, Acobiom, Montpellier
| | - P Dubreuil
- Signaling, Hematopoiesis and Mechanism of Oncogenesis, Inserm U1068, CRCM, Marseille; Institut Paoli-Calmettes, Marseille; Aix-Marseille University, UM 105, Marseille; CNRS, UMR7258, CRCM, Marseille; Clinical Development, AB Science, Paris
| | | | - Y Acin
- Clinical Development, AB Science, Paris
| | - A Moussy
- Clinical Development, AB Science, Paris
| | - O Hermine
- Clinical Development, AB Science, Paris; Department of Clinical Hematology, Necker Hospital, Paris; INSERM UMR 1163, Laboratory of Cellular and Molecular Mechanisms of Hematological Disorders and Therapeutic Implications, Paris; Paris Descartes - Sorbonne Paris Cité University, Imagine Institute, Paris; CNRS ERL 8254, Paris; Laboratory of Excellence GR-Ex, Paris; National Reference Center on Mastocytosis (CEREMAST), Paris
| | - P Hammel
- Department of Gastroenterology, Hôpital Beaujon, Clichy, France
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Kelrich A, Dubrovskii VG, Calahorra Y, Cohen S, Ritter D. Control of morphology and crystal purity of InP nanowires by variation of phosphine flux during selective area MOMBE. Nanotechnology 2015; 26:085303. [PMID: 25648852 DOI: 10.1088/0957-4484/26/8/085303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present experimental results showing how the growth rate, morphology and crystal structure of Au-catalyzed InP nanowires (NWs) fabricated by selective area metal organic molecular beam epitaxy can be tuned by the growth parameters: temperature and phosphine flux. The InP NWs with 20-65 nm diameters are grown at temperatures of 420 and 480 °C with the PH3 flow varying from 1 to 9 sccm. The NW tapering is suppressed at a higher temperature, while pure wurtzite crystal structure is preferred at higher phosphine flows. Therefore, by combining high temperature and high phosphine flux, we are able to fabricate non-tapered and stacking fault-free InP NWs with the quality that other methods rarely achieve. We also develop a model for NW growth and crystal structure which explains fairly well the observed experimental tendencies.
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Affiliation(s)
- A Kelrich
- Electrical Engineering Faculty, Technion-Israel Institute of Technology, Haifa 32000, Israel
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Kelrich A, Calahorra Y, Greenberg Y, Gavrilov A, Cohen S, Ritter D. Shadowing and mask opening effects during selective-area vapor-liquid-solid growth of InP nanowires by metalorganic molecular beam epitaxy. Nanotechnology 2013; 24:475302. [PMID: 24177750 DOI: 10.1088/0957-4484/24/47/475302] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Indium phosphide nanowires were grown by metalorganic molecular beam epitaxy using the selective-area vapor-liquid-solid method. We show experimentally and theoretically that the size of the annular opening around the nanowire has a major impact on nanowire growth rate. In addition, we observed a considerable reduction of the growth rate in dense two-dimensional arrays, in agreement with a calculation of the shadowing of the scattered precursors. Due to the impact of these effects on growth, they should be considered during selective-area vapor-liquid-solid nanowire epitaxy.
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Affiliation(s)
- A Kelrich
- Electrical Engineering Faculty, Technion-Israel Institute of Technology, Haifa 32000, Israel
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Troeller S, Linsel G, Huettig N, Bauer M, Graebsch C, Smirnova L, Pirow R, Liebsch M, Berger-Preiß E, Kock H, Oertel A, Ritter D, Knebel J. Air/liquid interface (ALI) technique for toxicity testing of gaseous compounds on human lung cells. Toxicol Lett 2013. [DOI: 10.1016/j.toxlet.2013.05.271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Switalla S, Knebel J, Ritter D, Dasenbrock C, Krug N, Braun A, Sewald K. Determination of genotoxicity by the Comet assay applied to murine precision-cut lung slices. Toxicol In Vitro 2012; 27:798-803. [PMID: 23274917 DOI: 10.1016/j.tiv.2012.12.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 12/10/2012] [Accepted: 12/13/2012] [Indexed: 12/30/2022]
Abstract
Precision-cut lung slices (PCLSs) are an organotypic lung model that is widely used in pharmacological, physiological, and toxicological studies. Genotoxicity testing, as a pivotal part of early risk assessment, is currently established in vivo in various organs including lung, brain, or liver, and in vitro in cell lines or primary cells. The aim of the present study was to provide the three-dimensional organ culture PCLS as a new ex vivo model for determination of genotoxicity using the Comet assay. Murine PCLS were exposed to increasing concentrations of ethyl methane sulfonate 'EMS' (0.03-0.4%) and formalin (0.5-5mM). Tissue was subsequently dissociated, and DNA single-strand breaks were quantified using the Comet assay. Number of viable dissociated lung cells was between 4×10(5) and 6.7×10(5)cells/slice. Even treatment with EMS did not induce toxicity compared to untreated tissue control. As expected, DNA single-strand breaks were increased dose-dependently and significantly after exposure to EMS. Here, tail length rose from 24μm to 75μm. In contrast, formalin resulted in a significant induction of DNA cross-links. The effects induced by EMS and formalin demonstrate the usefulness of PCLS as a new ex vivo lung model for genotoxicity testing in the early risk assessment of airborne substances in the future.
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Affiliation(s)
- S Switalla
- Fraunhofer Institute for Toxicology and Experimental Medicine, Airway Immunology, Nikolai-Fuchs-Str. 1, 30625 Hannover, Germany
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Yalon E, Cohen S, Gavrilov A, Ritter D. Evaluation of the local temperature of conductive filaments in resistive switching materials. Nanotechnology 2012; 23:465201. [PMID: 23093285 DOI: 10.1088/0957-4484/23/46/465201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The resistive switching effect in metal oxides and other dielectric materials is among the leading future non-volatile memory technologies. Resistive switching is widely ascribed to the formation and rupture of conductive filaments in the oxide, which are generated by temperature-enhanced nano-scale ion migration or other thermal effects. In spite of the central role of the local filament temperature on the switching effect, as well as on the conduction and reliability physics, no measurement methods of the filament temperature are yet available. In this work, we report on a method for evaluating the conducting filament temperature, using a metal-insulator-semiconductor bipolar transistor structure. The filament temperature is obtained by analyzing the thermal excitation rate of electrons from the filament Fermi level into the conduction band of a p-type semiconductor electrode. Measurements were carried out to obtain the conductive filament temperature in hafnia at varying ambient temperatures in the range of 3-300 K. Significant Joule heating of the filament was observed across the entire measured ambient temperature range. The extracted temperatures provide physical insight into the resistive switching effect.
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Affiliation(s)
- E Yalon
- Technion-Israel Institute of Technology, Haifa 32000, Israel.
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Lewitzka U, Scheffczyk R, Ritter D, Doucette S, Bauer M, Bschor T. No correlation between lithium serum levels and psychopathological features during the euthymic interval of patients with recurrent affective disorder. Pharmacopsychiatry 2011; 45:1-6. [PMID: 21989601 DOI: 10.1055/s-0031-1286343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
INTRODUCTION The aim of this prospective study was to investigate the influence of lithium serum levels on subclinical psychopathological features during the euthymic interval in patients with an affective disorder. METHODS The study included 54 patients with a recurrent affective disorder undergoing a continuous prophylactic lithium treatment (31 unipolar, 23 bipolar). The observation period lasted for 2 years and included 332 visits. Visits consisted of a detailed interview, a continuous measurement of lithium levels and the collection of validated scales including HAMD, YMRS, CGI, VAMS and the SCL-90R. Several correlations between lithium serum levels and different psychopathological features during the euthymic interval were calculated on an individual patient basis and on a group basis to reveal generally occurring correlations. RESULTS No generally occurring significant correlations between lithium serum levels and specific psychopathological features were found. Only on a single patient level, 32 significant correlations between lithium level and specific psychopathological features were found, partly indicating a negative and partly indicating a positive influence of higher lithium levels on psychopathological symptoms. Nevertheless, in the group analyses no significant correlations were found. DISCUSSION Higher lithium levels were not associated with an improved psychopathological status, but they were not associated with a worse status (due to a higher burden of side effects) either. According to the literature there is currently no strong evidence to treat patients with a higher lithium level. It is recommended to start with a lower level and to continue with individual adjustments in accordance to prophylactic efficacy and tolerability.
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Affiliation(s)
- U Lewitzka
- Department of Psychiatry and Psychotherapy, University Hospital Carl Gustav Carus, Dresden, Germany.
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Ritter D, Knebel J. Toxicological characterization of inhalable substances and aerosols in vitro: Enhancement of experimental methods by in situ fluorescence analysis of the cellular status during exposure. Toxicol Lett 2011. [DOI: 10.1016/j.toxlet.2011.05.608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lee K, Lillehoj H, Jang S, Li G, Bautista D, Phillips K, Ritter D, Lillehoj E, Siragusa G. Effects of coccidiosis control programs on antibody levels against selected pathogens and serum nitric oxide levels in broiler chickens. J APPL POULTRY RES 2011. [DOI: 10.3382/japr.2010-00218] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Bschor T, Ritter D, Lewitzka U, Bauer M, Uhr M, Ising M. Effects of lithium on the HPA axis in patients with unipolar major depression. Eur Psychiatry 2011. [DOI: 10.1016/s0924-9338(11)72319-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background(I)Profound alterations of the hypothalamic-pituitary-adrenocortical (HPA) axis regulation were repeatedly shown in depressed patients. The most sensitive challenge test of the HPA axis, the combined dexamethasone/CRH test (DEX/CRH test), shows an overstimulation of ACTH and cortisol in depressed patients. Under tricyclic antidepressant treatment, a normalization of the HPA axis overdrive was found to precede the clinical improvement.(II)Lithium is a well established drug for the treatment of affective disorders. Yet, its exact mode of action and its effects on the HPA axis are still unknown.Design and methodsThree 4-week studies with each 30 acutely depressed patients (unipolar, SCID I confirmed) were conducted. In study 1, patients refractory to a treatment trial with an antidepressant of at least four weeks were treated with lithium augmentation. In study 2 and 3, drug free patients were treated with lithium monotherapy or citalopram monotherapy respectively. Weekly HAM-D ratings were performed. In each study, the DEX/CRH test was conducted right before and four weeks after initiation of the pharmacotherapy.ResultsAll three pharmacological strategies showed good antidepressive efficacy. Both lithium monotherapy and lithium augmentation led to a (for most parameters significant) increase in the HPA axis activity. In contrast, citalopram monotherapy resulted in a decrease of the hormone response to the DEX/CRH test.
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Singh P, Wu T, Wendung M, Bendale P, Ware J, Ritter D, Zhang L. Mechanisms Causing Capacity Loss on Long Term Storage in NiMH System. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-496-25] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTCapacity recovery after long term storage and loaded storage is a critical issue with the NiMH system since its inception. A measurable loss in capacity is observed when cells are stored for long periods of time or discharged deeply to zero volts. The different mechanisms that are known to cause self discharge and capacity loss after storage and loaded storage will be the focus of this paper. Capacity loss after long term storage involves two main events. One is self discharge which causes the open circuit voltage(OCV) of the cell to drop. Self discharge is caused by decomposition of NiOOH, migration of metal ions and possible degradation of separator. Self discharge can be prevented by using separators which are stable at high temperatures and pH and have good ion trapping capability. Various separator types and treatments can play an important role in inhibiting metal ions from migrating thus reducing self discharge. Self discharge during storage causes a severe suppression in the voltage of the foam positive electrode. This drop in voltage causes a breakdown of the cobalt conductive network in the nickel positive electrode. Reduction of high valence cobalt(III) which forms the electrode's conductive network takes place at these low voltages. A permanent breakdown in the conductive network results in low efficiency of the cell on consecutive charge and discharge cycles. In addition, the cobalt in its lower valence states can migrate away from the electrode into the separator causing shorts. These events effect the charge and discharge efficiency of these cells thereby resulting in capacity loss. Various mechanisms causing self discharge which affect capacity recovery after long term storage and loaded storage are discussed in this paper.
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Jenkins M, Klopp S, Ritter D, Miska K, Fetterer R. Comparison of Eimeria species distribution and salinomycin resistance in commercial broiler operations utilizing different coccidiosis control strategies. Avian Dis 2010; 54:1002-6. [PMID: 20945780 DOI: 10.1637/9137-111109-reg.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The purpose of the present study was to evaluate the species composition and salinomycin sensitivity of Eimeria oocysts isolated from commercial broiler farms that differed by means of coccidiosis control (anticoccidial drugs [ACD] vs. live oocyst vaccines [VAC]). A comparison of Eimeria species composition and salinomycin sensitivity was also made before and after a producer switched from salinomycin to live oocyst vaccines. In general, no significant difference was observed in the concentration of Eimeria spp. oocysts in litter from VAC-utilizing farms compared to litter from ACD-utilizing farms. Application of PCR-based methods to detect coccidia found that Eimeria species distribution in litter from VAC operations more closely resembled the species composition in the live oocyst vaccines. Drug sensitivity testing found that Eimeria oocysts from VAC operations displayed greater salinomycin sensitivity as measured by weight gain and feed conversion efficiency compared to oocysts from ACD farms. These findings provide additional evidence for the usefulness of live oocyst vaccines to restore ionophore sensitivity in poultry operations that contain an ionophore-resistant population of Eimeria spp. oocysts.
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Affiliation(s)
- M Jenkins
- Animal Parasitic Diseases Laboratory, Agricultural Research Service, USDA, Beltsville, MD 20705, USA.
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23
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Switalla S, Knebel J, Ritter D, Krug N, Braun A, Sewald K. Effects of acute in vitro exposure of murine precision-cut lung slices to gaseous nitrogen dioxide and ozone in an air–liquid interface (ALI) culture. Toxicol Lett 2010; 196:117-24. [DOI: 10.1016/j.toxlet.2010.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2010] [Revised: 03/12/2010] [Accepted: 04/07/2010] [Indexed: 10/19/2022]
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24
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Huber R, Ritter D, Hering T, Kensy F, Wang L, Büchs J. Optimierung der Proteinexpression im Hochdurchsatz. CHEM-ING-TECH 2009. [DOI: 10.1002/cite.200950023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Affiliation(s)
- C Schmidgunst
- Siemens AG, Medical Solutions, Special System Division, Allee am Roethelheimpark 2, 91052 Erlangen, Germany.
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26
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Bschor T, Ritter D, Lewitzka U, Bauer M, Adli M, Baethge C, Uhr M, Ising M. Effects of lithium on the HPA axis in patients with unipolar major depression. Pharmacopsychiatry 2005. [DOI: 10.1055/s-2005-918650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Solberg T, Chow P, Sorensen S, Wink N, Mitschke M, Ritter D, Agazaryan N, Lee S. Image guided radiotherapy using a mobile kilovoltage x-ray device. Int J Radiat Oncol Biol Phys 2004. [DOI: 10.1016/j.ijrobp.2004.07.623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
The in vitro study of adverse cellular effects induced by inhaled pollutants poses a special problem due to the difficulties of exposing cultured cells of the respiratory tract directly to test atmospheres that can include complex gaseous and particulate mixtures. In general, there is no widely accepted in vitro exposure system. However, in vitro methods offer the unique possibility for use of human cells, developed and validated cell culture and exposure device (CULTEX(1)) using the principle of the air/liquid exposure technique. Cells of the respiratory tract are grown on porous membranes in transwell inserts. After removal of the medium, the cells can be treated on their superficial surfaces with the test atmosphere, and at the same time they are supplied with nutrients through the membrane below. In comparison with other experimental approaches, the goal of our studies is to analyze the biological effects of test atmospheres under environmental conditions, i.e. without humidifying the atmosphere or adding additional CO(2). The system used is small and flexible enough independent of a cultivation chamber and thus offers the opportunity for onsite study of indoor and outdoor atmospheres in the field. The efficacy of the exposure device has already been demonstrated in the analysis of dose-dependent cytotoxic and genotoxic effects of exposure of epithelial lung cells to complex mixtures such as native diesel exhaust and side-stream smoke.
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Affiliation(s)
- Michaela Aufderheide
- Fraunhofer Institute of Toxicology and Aerosol Research, Drug Research and Clinical Inhalation, Nikolai-Fuchs-Strasse 1, 30625, Hannover, Germany.
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30
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Abstract
To investigate the effects of native diesel motor exhaust on human lung cells in vitro, a new experimental concept was developed using an exposure device on the base of the cell cultivation system CULTEX (Patent No. DE19801763.PCT/EP99/00295) to handle the cells during a 1-h exposure period independent of an incubator and next to an engine test rig. The final experimental set-up allows the investigation of native (chemically and physically unmodified) diesel exhaust using short distances for the transportation of the gas to the target cells. The analysis of several atmospheric compounds as well as the particle concentration of the exhaust was performed by online monitoring in parallel. To validate the complete system we concentrated on the measurement of two distinct viability parameters after exposure to air and undiluted, diluted and filtered diesel motor exhaust generated under different engine operating conditions. Cell viability was not influenced by the exposure to clean air, whereas dose-dependent cytotoxicity was found contingent on the dosage of exhaust. Additionally, the quality of exhaust, represented by two engine operating conditions (idling, higher load), also showed well-distinguishable cytotoxicity. In summary, the experimental set-up allows research on biological effects of native engine emissions using short exposure times.
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Affiliation(s)
- J W Knebel
- Fraunhofer Institute of Toxicology and Aerosol Research, Nikolai-Fuchs Str. 1, 30625 Hannover, Germany
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31
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Ritter D, Knebel JW, Aufderheide M. In vitro exposure of isolated cells to native gaseous compounds--development and validation of an optimized system for human lung cells. Exp Toxicol Pathol 2001; 53:373-86. [PMID: 11817107 DOI: 10.1078/0940-2993-00204] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
An exposure system for adherent growing cells to native gaseous compounds was developed using air/liquid culture techniques on the basis of the Cultex system'. In contrast to other exposure systems the reproducible testing of native environmentally relevant gases without changing their physical or chemical properties including heating, CO2- content and humidity is possible. Specially designed systems for medium flow and gas support guarantee the nutrification and humidification as well as the direct gas contact of the exposed cells which are cultivated on microporous membranes (0.4 microm pore size). The system works independently of a cell culture incubator offering the possibility to analyze any relevant gas mixture directly under indoor or outdoor conditions. Several experimental approaches were carried out to characterize the properties of the system. In exploratory experiments without cells, the reproducibility and quality of the gas/membrane contact could be demonstrated. Exposures of human lung fibroblasts (Lk004 cells) and human lung epithelial cells (HFBE-21 cells) to synthetic air, ozone (202 ppb, 510 ppb) and nitrogen dioxide (75 ppb to 1,200 ppb) established that cells could be treated for 120 minutes without significant loss of cellular viability. At the same time, the experiments confirmed that such exposure times are long enough to detect biological effects of environmentally relevant gas mixtures. The analysis of viability (viable cell number, tetrazoliumsalt cleavage) and intracellular end-points (oxidized/reduced glutathione, ATP/ADP) showed that both gases induced relevant cellular changes. In summary, the efficiency and practicability of this newly developed exposure system for adherent human lung cells could be clearly demonstrated.
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Affiliation(s)
- D Ritter
- Department In Vitro Toxicology, Fraunhofer Institute for Toxicology and Aerosol Research, Hannover, Germany
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32
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Aufderheide M, Ritter D, Knebel JW, Scherer G. A method for in vitro analysis of the biological activity of complex mixtures such as sidestream cigarette smoke. Exp Toxicol Pathol 2001; 53:141-52. [PMID: 11484832 DOI: 10.1078/0940-2993-00187] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Studies of the cytotoxicity of air contaminants such as gaseous or particulate compounds and complex mixtures have traditionally used in animal experiments because of the difficulties in exposing cell cultures directly to these substances. New cultivation and exposure techniques enhance the efficiency of in vitro methods, as demonstrated by a new system called CULTEX* which uses a transwell membrane technique for direct exposure of complex mixtures like sidestream cigarette smoke at the air/liquid interface. The factors influencing the susceptibility of human bronchial epithelial cells (e.g. gas flow rate or duration of exposure) were studied and the cells were finally exposed for one hour to clean air or different concentrations of sidestream smoke. The biological parameters estimated were number of cells, metabolic activity and glutathione concentration. After exposure of the cells to sidestream cigarette smoke, dose-dependent effects were measured. Thus, the introduction of these cultivation and exposure techniques offers new testing strategies for the toxicological evaluation of a broad range of airborne and inhalable compounds.
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Affiliation(s)
- M Aufderheide
- Fraunhofer Institute of Toxicology and Aerosol Research Drug Research and Clinical Inhalation, Hannover, Germany.
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33
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Abstract
The diagnosis of acute infection with human immunodeficiency virus (HIV) presents a challenge for the primary care provider. We present a case of early HIV infection and discuss the limitations of the currently established diagnostic algorithm for HIV infection. We conclude that alternative diagnostic testing for human immunodeficiency virus type 1 (HIV-1) RNA is warranted in certain clinical settings. Appropriate, early diagnosis of HIV infection may improve the patient's outcome and provide additional public health benefits by reducing transmission of disease.
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Affiliation(s)
- A A Suarez
- Department of Pathology, Saint Louis University School of Medicine, Missouri, USA
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34
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Chu CC, Henneberry TJ, Natwick ET, Ritter D, Birdsall SL. Efficacy of CC traps and seasonal activity of adult Bemisia argentifolii (Homoptera: Aleyrodidae) in Imperial and Palo Verde Valleys, California. J Econ Entomol 2001; 94:47-54. [PMID: 11233132 DOI: 10.1603/0022-0493-94.1.47] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Adult whitefly Bemisia argentifolii Bellows & Perring trap (CC trap) catches were compared with suction type trap catches. CC trap catches were significantly correlated to the suction trap catches. Higher numbers of B. argentifolii adults were caught in CC traps oriented toward an untreated, B. argentifolii-infested, cotton field as compared with traps oriented toward Bermuda grass fields, farm roads, or fallow areas. CC trap catches at five heights above ground (from 0 to 120 cm) were significantly related to each other in choice and no-choice studies. CC trap catches were low in the Imperial and Palo Verde Valleys from late October to early June each of 1996, 1997, and 1998. Trap catches increased with increasing seasonal air temperatures and host availability. Trap catches were adversely affected by wind and rain. Abrupt trap catch increases of 40- to 50-fold for 1-2 d in late June to early July followed by abrupt decreases in adult catches suggest migrating activity of adults from other nearby crop sources.
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Affiliation(s)
- C C Chu
- Western Cotton Research Laboratory, USDA-ARS, Phoenix, AZ 85040, USA
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35
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Galambos C, Brink DS, Ritter D, Chung HD, Creer MH. False-positive plasma troponin I with the AxSYM analyzer. Clin Chem 2000; 46:1014-5. [PMID: 10894851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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36
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Ritter D, Taylor JF, Hoffmann JW, Carnaghi L, Giddings SJ, Zakeri H, Kwok PY. Alternative splicing for the alpha1 subunit of soluble guanylate cyclase. Biochem J 2000; 346 Pt 3:811-6. [PMID: 10698711 PMCID: PMC1220917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Soluble guanylate cyclase (sGC), the receptor for nitric oxide, is a heterodimer consisting of alpha and beta subunits. We investigated the mRNA species for the alpha(1) subunit in human brain, heart, artery and immortalized B-lymphocytes. Three mRNA species were identified in these tissues. The major mRNA species contained the full expression sequence of the alpha(1) subunit. Two other types of mRNA were detected in which 5' sequences were deleted by splicing (506-590 and 412-590). Each of these deletions included the predicted translation start site, indicating that translation of these two alternatively spliced RNA species does not result in the production of full-length alpha(1) subunits. The relative amounts of the two mRNA species with deletions of the translation start site differed significantly between cell lines of immortalized B-lymphocytes from different individuals. sGC enzymic activity was significantly decreased in cellular extracts from cell lines with high proportions of mRNA species containing the deletion 506-590 when compared with extracts from cell lines that contained mostly mRNA without this deletion.
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Affiliation(s)
- D Ritter
- Department of Pathology, Saint Louis University School of Medicine, St Louis, MO 63104, USA.
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37
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Abstract
We studied the feasibility of routine diagnostic testing for HIV-1 RNA at a publicly funded testing site. HIV-1 RNA was determined with a commercial polymerase chain reaction assay in pooled seronegative blood samples submitted for HIV testing to a public health laboratory. Recovery of HIV-1 RNA from the samples was estimated as at least 8% of viral RNA that was found in freshly prepared plasma. We estimated that screening for HIV-1 RNA in serum pools would result in the identification of blood specimens from more than 95% of acutely infected patients. The frequency of HIV-1 RNA in seronegative blood samples was estimated to be between 19 and 601 per 10(6) submitted specimens. The ratio of HIV-1 RNA positive and seronegative samples to specimens with HIV-1 antibodies confirmed by Western blot was estimated to be between 0.2% and 6.6%. The reagent costs for identifying 1 HIV-infected blood sample were 10-fold higher with the commercially available HIV-1 RNA assay compared with the HIV antibody enzyme-linked immunosorbent assay. Diagnostic testing for HIV-1 RNA may be warranted in high-risk populations since acutely infected patients may benefit most from anti-retroviral therapy and are thought to contribute disproportionately to the HIV epidemic.
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Affiliation(s)
- D Ritter
- Department of Pathology, St Louis University School of Medicine, MO, USA
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38
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Ritter D, Knebel J, Aufderheide M, Mohr U. Development of a Cell Culture Model System for Routine Testing of Substances Inducing Oxidative Stress. Toxicol In Vitro 1999; 13:745-51. [DOI: 10.1016/s0887-2333(99)00063-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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39
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Polski JM, Creer MH, Ritter D, Johnston MF. Polyethylene glycol-induced immunoglobulin precipitation may cause invalidation of antiglobulin tests. Transfusion 1999; 39:537-9. [PMID: 10336008 DOI: 10.1046/j.1537-2995.1999.3905537.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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40
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Eliason SC, Ritter D, Chung HD, Creer M. Interlaboratory variability for total homocysteine analysis in plasma. Clin Chem 1999; 45:315-6. [PMID: 9931068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
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41
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Knebel JW, Ritter D, Aufderheide M. Development of an in vitro system for studying effects of native and photochemically transformed gaseous compounds using an air/liquid culture technique. Toxicol Lett 1998; 96-97:1-11. [PMID: 9820642 DOI: 10.1016/s0378-4274(98)00044-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An experimental in vitro model was established to study the effects of environmentally relevant gaseous compounds on lung cells. The technical unit consists of a gas reaction chamber (2400 l) with a sun-simulator to produce and photochemically transform gaseous mixtures and compounds at the upper limit of environmentally relevant concentrations. Rat lung cells were exposed on transwells in a perspex chamber inside an incubator, into which the gaseous mixtures were conducted. Analysis of the gas phase was performed inside the reaction chamber and at the outlet of the exposure box to assess the effective exposure concentrations. The growth of the cells on PET-membranes allowed direct cell exposure with a minimal barrier for contact between gas and cells. To assess the cytotoxicity, the following biochemical markers for the cellular status after exposure were determined: amount of dsDNA, WST, BrdU-incorporation after exposure, LDH release into the culture medium, activity of glutathione S-transferases and esterases. Using this system, dose-dependent cytotoxicity was found for NO2 in the concentration range from 80 to 360 ppb and strong cytotoxic effects for ozone in the concentration range from 225 to 500 ppb. Exposure to purified air did not show significant effects. In addition, some irradiated gas mixtures (photo smog) showed cytotoxicity whereas non-irradiated mixtures did not.
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Affiliation(s)
- J W Knebel
- Institut für Experimentelle Pathologie, Medizinische Hochschule Hannover, Germany.
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42
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Aufderheide M, Ritter D, Knebel J. Cytotoxic activity of PAN (peroxyacetyl nitrate), an environmental pollutant, on rat lung cells. Toxicol Lett 1998. [DOI: 10.1016/s0378-4274(98)80949-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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43
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McCall WG, Alves SL, Brooks DY, Fallacaro MD, Gray GC, Ritter D. An analysis of factors influencing nurse anesthesia educational program director turnover. 1996-1997 AANA Education Committee. AANA J 1997; 65:537-542. [PMID: 9464008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Ye P, Umayahara Y, Ritter D, Bunting T, Auman H, Rotwein P, D'Ercole AJ. Regulation of insulin-like growth factor I (IGF-I) gene expression in brain of transgenic mice expressing an IGF-I-luciferase fusion gene. Endocrinology 1997; 138:5466-75. [PMID: 9389533 DOI: 10.1210/endo.138.12.5600] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Insulin-like growth factor I (IGF-I) plays an important role in the development and function of the central nervous system (CNS). Little is known, however, about the factors and mechanisms involved in regulation of CNS IGF-I gene expression. To facilitate our goal to define mechanisms of IGF-I gene regulation in the CNS, we generated several lines of transgenic (Tg) mice that express firefly luciferase (LUC) under control of a 11.3-kb fragment from the 5' region of the rat IGF-I gene. Consistent with expression of the native IGF-I gene in murine brain, expression of the transgene predominated in neurons and astrocytes and used promoter 1, the major IGF-I promoter in the CNS and in most tissues. Transgene messenger RNA and protein expression rapidly increased after birth and peaked at postnatal (P) day 4 in all brain regions studied. LUC activities in all regions then gradually decreased to 0.5-4% of their peak values at P31, except for the olfactory bulb, which maintained about one third of its maximal activity. Compared with littermate controls, administration of dexamethasone decreased LUC activity and transgenic IGF-I messenger RNA abundance, whereas GH significantly increased the expression of the transgene. Addition of GH to cultured fetal brain cells from Tg mice for 12 h also increased LUC activity in a dose-dependent manner (77-388%). These results show that this IGF-I promoter transgene is expressed in a fashion similar to the endogenous IGF-I gene, and thus indicates that the transgene contains cis-elements essential for developmental, GH, and glucocorticoid regulation of IGF-I gene expression in the CNS. These Tg mice should serve as an useful model to study mechanisms of IGF-I gene regulation in the brain.
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Affiliation(s)
- P Ye
- Department of Pediatrics, University of North Carolina at Chapel Hill, 27599, USA
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45
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Landt M, Ritter D, Lai K, Benke PJ, Elsas LJ, Steiner RD. Black children deficient in galactose 1-phosphate uridyltransferase: correlation of activity and immunoreactive protein in erythrocytes and leukocytes. J Pediatr 1997; 130:972-80. [PMID: 9202622 DOI: 10.1016/s0022-3476(97)70286-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A recent study found a high prevalence of a missense mutation (S135L) in the gene for galactose 1-phosphate uridyltransferase (GALT) in black children with galactosemia (J Pediatr 1996; 128:89-95). In the present study, GALT activity and GALT protein content were measured in erythrocytes and leukocytes of eight black and seven white galactosemic (GALT-deficient) children, for correlation with the presence of the S135L and Q188R (highly prevalent in white galactosemic children) missense mutations. The S135L mutation was found in 9 of 16 alleles of black children but not in white children; the Q188R mutation was found in 10 of 14 alleles examined in white galactosemic children and in 4 of 16 alleles in black galactosemic children. The GALT activity was near zero in the erythrocytes of white and black galactosemic children (0.26 +/- 0.28 vs 0.33 +/- 0.25 mumol/hr per gram of hemoglobin, respectively; p = 0.61) (normal 17 to 26 mumol/hr per gram), and no correlation of erythrocyte activity with genotype was observed. The GALT activity was higher in the leukocytes of black galactosemic children compared with white children (5 +/- 6 vs 1 +/- 2 mumol/hr per gram, respectively) (normal 172 to 374 mumol/hr per gram), but the difference was not statistically significant (p = 0.11). Analysis by genotype revealed that the two S135L homozygotes had much more leukocyte activity (9 and 17 mumol/hr per gram) than Q188R homozygotes or than all non-S135L allelic genotypes. Compound heterozygotes (S135L/G) had intermediate activity. The GALT protein was not detectable by Western blot in the erythrocytes of either white or black galactosemic children, as determined by antibodies specific for both C- and N-terminal sequences. The GALT protein was undetectable in the leukocytes of white galactosemic children, but leukocytes from black galactosemic children with the S135L mutation contained reduced but readily detectable GALT protein. Erythrocyte galactose 1-phosphate levels were significantly lower in galactosemic children with an S135L mutant allele (1.1 +/- 0.2 gm/dl) compared with children who had other mutations (3.1 +/- 0.9 mg/dl; p = 0.0001). The correlation of protein content data with activity levels in the blood cells suggests that the S135L missense mutation affects the stability of GALT protein to produce a deficiency state.
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Affiliation(s)
- M Landt
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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46
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Ritter D, Cortese CM, Edwards LC, Barr JL, Chung HD, Long C. Interference with testing for lysergic acid diethylamide. Clin Chem 1997; 43:635-7. [PMID: 9105265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We found a high rate (4.2%) of positive results for lysergic acid diethylamide (LSD) by Emit in 1898 urine samples that were submitted primarily from psychiatric patients for drugs-of-abuse (DOA) testing. Specimens that tested positive for LSD by Emit subsequently tested negative for LSD with two RIAs. Furthermore, LSD was not detected in randomly selected Emit-positive urine samples by gas chromatography-mass spectrometry. Normal urine samples tested positive for LSD by Emit when they were supplemented with therapeutic medications that were prescribed for patients with positive urine LSD results by Emit. These therapeutic drugs interfered specifically with the Emit assay for LSD, since other Emit DOA tests were not affected by these medications at the tested concentrations.
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Affiliation(s)
- D Ritter
- Pathology and Laboratory Medicine, John Cochran Veterans Affairs Medical Center, Saint Louis, MO 63106, USA.
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47
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Abstract
It was recently reported that the epaxial muscles of a lizard, Varanus salvator, function to stabilize the trunk during locomotion, and it was suggested that this stabilizing role may be a shared derived feature of amniotes. This result was unexpected because it had previously been assumed that the epaxial muscles of lizards function to produce lateral bending during locomotion and that only in mammals and birds were the epaxial muscles active in stabilizing the trunk. These results and the inferences made from them lead to two questions. (1) Is the pattern of epaxial muscle activity observed in V. salvator representative of a basal lizard condition or is it a derived condition that evolved within lizards? (2) If the epaxial muscles do not produce lateral bending, which muscles do carry out this function? These questions were addressed by collecting synchronous electromyographic (EMG) and kinematic data from two lizard species during walking and running. EMG data were collected from the epaxial muscles of a lizard species from a basal clade, Iguana iguana, in order to address the first question. EMG data were collected from the hypaxial muscles of both Iguana iguana and Varanus salvator to address the second question. The timing of epaxial muscle activity in Iguana iguana relative to the kinematics of limb support and lateral trunk bending is similar to that observed in Varanus salvator, a finding that supports the hypothesis that the epaxial muscles stabilize the trunk during locomotion in lizards and that this stabilizing role is a basal feature of lizards. Therefore, a stabilizing function of the epaxial muscles is most parsimoniously interpreted as a basal amniote feature. In both Iguana iguana and Varanus salvator, the activity of two of the hypaxial muscles, the external oblique and rectus abdominis, is appropriately timed for the production of lateral bending. This indicates that elements of the hypaxial musculature, not the epaxial musculature, are the primary lateral bending muscles of lizards.
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Kelley PD, Brink DS, Joist JH, Ritter D. Lactate dehydrogenase isoenzyme utilization. Clin Chem 1996. [DOI: 10.1093/clinchem/42.10.1723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kelley PD, Brink DS, Joist JH, Ritter D. Lactate dehydrogenase isoenzyme utilization. Clin Chem 1996; 42:1723-4. [PMID: 8855169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Abstract
STUDY OBJECTIVE To evaluate the effects of oral, intramuscular (i.m.) and intravenous (i.v. glycopyrrolate on oral and gastric secretions, and to assess how these routes of administration change intubating conditions. DESIGN Randomized, double-blinded study. SETTING University hospital operating room. PATIENTS 37 ASA status I and II general anesthesia patients. INTERVENTIONS Patients were randomized to receive glycopyrrolate or placebo just before surgery by three routes: oral, i.m., and i.v.. Glycopyrrolate was received once by one route and placebo by the other two routes. A placebo group received three placebos and no glycopyrrolate. MEASUREMENTS AND MAIN RESULTS Mouth conditions and intubating conditions were qualitatively assessed by the patient and the intubating anesthesiologist. No difference between groups was noted. Oral and gastric volumes were measured and showed significantly less gastric volume for the i.v. group as compared with the other groups. Oral secretions were reduced in both the i.v. and i.m. groups when compared with placebo or glycopyrrolate administered orally. CONCLUSIONS Preoperative glycopyrrolate is significantly more effective at reducing oral and gastric secretions if administered intravenously immediately before induction.
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Affiliation(s)
- C A Bernstein
- Department of Anesthesiology, University of California, Irvine Medical Center, Orange, CA 92668, USA
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