43 results on '"Schaer R"'
Search Results
2. In vitro IFN-gamma production by goat blood cells after stimulation with somatic and secreted Corynebacterium pseudotuberculosis antigens
- Author
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Meyer, R., Regis, L., Vale, V., Paule, B., Carminati, R., Bahia, R., Moura-Costa, L., Schaer, R., Nascimento, I., and Freire, S.
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- 2005
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3. Vascular endothelial growth factor (VEGF) levels as a tool to discriminate between malignant and nonmalignant ascites
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NASCIMENTO, I., SCHAER, R., LEMAIRE, D., FREIRE, S., PAULE, B., CARVALHO, S., MEYER, R., and SCHAER-BARBOSA, H.
- Published
- 2004
4. Valeur de la tomographie par émission de positons au ( 18 F)-fluorodésoxyglucose pour prédire la récidive dans les cancers ORL non oropharyngé pris en charge par chimioradiothérapie
- Author
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Castelli, J., primary, Depeursinge, A., additional, Nditifei-Ndoh, V., additional, Devillers, A., additional, Dicente, Y., additional, Schaer, R., additional, Prior, J., additional, Bourhis, J., additional, Sire, C., additional, and de Crevoisier, R., additional
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- 2017
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5. The medGIFT Group in ImageCLEFmed 2013
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Herrera, A. G. S., Markonis, D., Schaer, R., Eggel, I., and Henning Müller
- Abstract
This article presents the participation of the medGIFT group in ImageCLEFmed 2013. Since 2004, the group has participated in the medical image retrieval tasks of ImageCLEF each year. There are four types of tasks for ImageCLEFmed 2013: modality classification, image-based retrieval, case-based retrieval and a new task on compound figure separation. The medGIFT group participated in all four tasks. MedGIFT is developing a system named ParaDISE (Parallel Distributed Image Search Engine), which is the successor of GIFT (GNU Image Finding Tool). The alpha version of ParaDISE was used to run the experiments in the competition. The focus was on the use of multiple features in combinations with novel strategies, i.e, compound figure separation for modality classification or modality filtering for ad-hoc image and case-based retrieval.
- Published
- 2013
6. Implémentation d’un itinéraire clinique dans le système d’information clinique de l’Hôpital du Valais
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none Schaer R, Petignat P-A, Gnaegi A
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- 2011
7. [Local democracy and social control of nanotechnologies : the 'Grenoblois' publics can they take part in the scientific and technical choices ? Report of mission for La Métro. Final report]
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Callon, M., DIANOUX, L., Fourniau, J.M., Gilbert, C., Hermitte, Marie-Angèle, Joly, Pierre Benoit, Joseph, Carmille, Kaufmann, A., Larrere, R., Neubauer, Claudia, Schaer, R., Inconnu, Transformations Sociales et Politiques liées aux Vivants (TSV), Institut National de la Recherche Agronomique (INRA), and ProdInra, Migration
- Subjects
[SHS] Humanities and Social Sciences ,Environnement, espace et société ,[SHS]Humanities and Social Sciences - Abstract
Contrat ; B06106 ; Accompagnement de projets scientifiques dans le domaine des nanosciences et des biotechnologies Diffusion du document : INRA Etablissement d'Economie et Sociologie rurales 65 boulevard de Brandebourg 94205 Ivry Cedex (FRA); Un groupe de spécialistes des relations entre science et société, chercheurs académiques et associatifs a été chargé par La Métro (Communauté des Communes de l'agglomération grenobloise) de porter un diagnostic sur l'état des projets de développement des nanotechnologies et sur les débats publics dont ils font l'objet et de faire des recommandations sur les façons d'associer les publics grenoblois aux choix scientifiques et techniques. Le rapport rend compte de ce diagnostic, nécessaire à l'appréciation de la pertinence des différents dispositifs de participation des publics à l'élaboration des choix scientifiques et techniques, et des pistes qu'il convient d'explorer afin d'assurer leur inscription durable dans la vie de l'agglomération grenobloise.
- Published
- 2005
8. Le musee du XVIIIe siecle: l'apogee et le chant du cygne de l'encyclopedisme
- Author
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Meijers, D.J., Schaer, R., and Faculteit der Letteren
- Published
- 1996
9. Implémentation d’un itinéraire clinique dans le système d’information clinique de l’Hôpital du Valais
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Schaer R, Petignat P-A, Gnaegi A, none, primary
- Published
- 2011
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10. Flavonoid Rutin Alters the Viability and Function of Mitogen-Stimulated Splenocytes and Thymocytes Compared with Non Stimulated Cells
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Roseghini, R., primary, Rocha, D.S., additional, Clarêncio, J., additional, Costa, S.L., additional, Costa, M.F.D., additional, Tardy, M., additional, Nascimento, R., additional, Schaer, R., additional, Velozo, E., additional, Meyer, R., additional, and Freire, S., additional
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- 2007
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11. Different Effects of Arborinine Alkaloid Obtained from BrazilianErthela baihensison Spleen and Thymus Cells Stimulatedin Vitrowith Different Mitogens
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Roseghini, R., primary, Moreira, P., additional, Vale, V., additional, Pinheiro, A.M., additional, Costa, J.F.O., additional, Bittencourt, T., additional, Nascimento, I., additional, Schaer, R., additional, Velozo, E., additional, El-Bachá, R., additional, Meyer, R., additional, and Freire, S., additional
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- 2006
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12. Evaluating angiogenic cytokines VEGF, basic FGF and TGF- β1 as tumor markers in ascites
- Author
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Nascimento, I. L., primary, Barbosa, H. S., additional, Schaer, R. E., additional, Lemaire, D. C., additional, Freire, S. M., additional, Vale, V., additional, Salomao, M. L., additional, Lessa, G. S., additional, and Meyer, R. J., additional
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- 2005
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13. Three-phase partitioning as an efficient method for extraction/concentration of immunoreactive excreted–secreted proteins of Corynebacterium pseudotuberculosis
- Author
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Paule, B.J.A, primary, Meyer, R, additional, Moura-Costa, L.F, additional, Bahia, R.C, additional, Carminati, R, additional, Regis, L.F, additional, Vale, V.L.C, additional, Freire, S.M, additional, Nascimento, I, additional, Schaer, R, additional, and Azevedo, V, additional
- Published
- 2004
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14. Experimental Corynebacterium pseudotuberculosis primary infection in goats: kinetics of IgG and interferon-γ production, IgG avidity and antigen recognition by Western blotting
- Author
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Paule, B.J.A, primary, Azevedo, V, additional, Regis, L.F, additional, Carminati, R, additional, Bahia, C.R, additional, Vale, V.L.C, additional, Moura-Costa, L.F, additional, Freire, S.M, additional, Nascimento, I, additional, Schaer, R, additional, Goes, A.M, additional, and Meyer, R, additional
- Published
- 2003
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15. Pancreatic tumors: evaluation with endoscopic US, CT, and MR imaging.
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Müller, M F, primary, Meyenberger, C, additional, Bertschinger, P, additional, Schaer, R, additional, and Marincek, B, additional
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- 1994
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16. Different Effects of Arborinine Alkaloid Obtained from Brazilian Erthela baihensis on Spleen and Thymus Cells Stimulated in Vitro with Different Mitogens.
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Roseghini, R., Moreira, P., Vale, V., Pinheiro, A.M., Costa, J.F.O., Bittencourt, T., Nascimento, I., Schaer, R., Velozo, E., El-Bachá, R., Meyer, R., and Freire, S.
- Subjects
ALKALOIDS ,MICROBIAL metabolites ,MITOGENS ,LECTINS ,APOPTOSIS ,CELL death - Abstract
The present study has examined the effects of arborinine, an alkaloid obtained from Erthela bahiensis , a Brazilian plant popularly used as diuretic, antidiabetic, antithermic and expectorant, on the viability and function of immune system cells in vitro using a murine model. Rat spleen and thymus cells were cultured with 10nM, 1µM e 10µM of the drug in the presence or absence of pokeweed (PWM), lipopolysaccharide (LPS), or concanavallin (ConA) mitogens. Cellular proliferation was analyzed by H 3 ‐thymidin uptake after 48 and 72 hr. Our results showed an inhibitory effect of arborinine on splenocytes proliferation under ConA or PWM stimulation and increased apoptosis on splenocytes and thymocytes stimulated with PWM in 24 hr. A decrease was observed on Interferon gamma (IFN-γ) production by ConA- or LPS-stimulated splenocytes in 48 hr and 72 hr and ConA- or PWM-stimulated thymocytes in 72 hr. In contrast, an increase on lymphoproliferation was observed on LPS-stimulated splenocytes and ConA- or PWM-stimulated thymocytes in 48 hr. On this period, apoptosis decreased on LPS- or PWM-stimulated splenocytes and IFN-γ production increased in PWM stimulated thymocytes. Arborinine also induced a decrease on Interleukin-10 production by splenocytes and thymocytes stimulated with ConA or PWM. There was no significant variation on the necrosis rate of the cells treated with arborinine or any change on their viability or function values in the absence of mitogenic stimulus. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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17. VISCERAL -VISual concept extraction challenge in RAdioLogy: ISBI 2014 challenge organization
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Del Toro, O. A. J., Goksel, O., Menze, B., Müller, H., Georg Langs, Weber, M. -A, Eggel, I., Gruenberg, K., Holzer, M., Jakab, A., Kontokotsios, G., Krenn, M., Fernandez, T. S., Schaer, R., Taha, A. A., Winterstein, M., and Hanbury, A.
18. Microfabrication of free-standing micro-solid oxide fuel cells on Foturan® and silicon substrates
- Author
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Tölke, R., Evans, A., Rupp, J. L. M., Bieberle-Hütter, A., Schlupp, M. V. F., Scherrer, B., Prestat, M., Gauckler, L. J., Courbat, J., Briand, D., de Rooij, N. F., Muralt, P., Yan, Y., Schaer, R., and Böni, H.
- Abstract
Due to their high specific energy and energy density, micro-solid oxide fuel cells1,2 (µ-SOFCs) are seen as one of the technologies that could help satisfying the continuously increasing demand for electric energy in portable electronic devices. The µ-SOFC is a less than 1 µm thin free-standing membrane. The membrane consists of ceramic and metallic thin film layers integrated on a micro-structurable substrate based on MEMS technologies. In this study, Foturan® glass ceramic and silicon µ-SOFCs substrates are compared in terms of etching behavior, mechanical and thermomechanical properties
19. Overview of the VISCERAL challenge at ISBI 2015
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Goksel, O., Foncubierta-Rodríguez, A., Del Toro, O. A. J., Müller, H., Langs, G., Weber, M. -A, Menze, B., Eggel, I., Gruenberg, K., Winterstein, M., Holzer, M., Krenn, M., Kontokotsios, G., Metallidis, S., Schaer, R., Taha, A. A., András Jakab, Fernandez, T. S., and Hanbury, A.
20. Valeur de la tomographie par émission de positons au (18F)-fluorodésoxyglucose pour prédire la récidive dans les cancers ORL non oropharyngé pris en charge par chimioradiothérapie.
- Author
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Castelli, J., de Crevoisier, R., Depeursinge, A., Dicente, Y., Schaer, R., Nditifei-Ndoh, V., Devillers, A., Prior, J., Bourhis, J., and Sire, C.
- Abstract
Objectif de l’étude Les objectifs de ce travail étaient d’identifier, pour des cancers non oropharyngé localement évolués pris en charge par chimioradiothérapie, des paramètres de tomographie par émission de positons (TEP) quantitatifs prédictif de la survie sans progression et dans un second temps d’établir un score pronostique. Matériel et méthode Un total de 78 patients, avec un suivi médian de 23 mois, issus de trois centres (Rennes, Lorient et Lausanne), ont été inclus dans cette étude rétrospective. En plus de la standard uptake value maximale (SUVMax), les paramètres de TEP de volume ( metabolic tumor volume [MTV] et total lesion glycolysis [TLG]) ont été calculés en utilisant différentes valeurs de seuillage en valeur absolue (de 0 à 20) ou relative (de 0 à 100 % de la SUVMax). L’ensemble des paramètres cliniques et de TEP a été analysé et une corrélation avec la survie sans récidive a été recherchée. Un modèle pronostique de survie sans progression a été défini. Une validation interne a été réalisée par une méthode de ré-échantillonnage ( bootstrap ). Résultats En analyse multifactorielle, le MTV était le seul facteur pronostique indépendant de la survie sans progression, alors que les facteurs classiques cliniques ([stade T, volume tumoral macroscopique], stade selon l’American Joint Committee on Cancer [AJCC]) étaient peu ou pas significatifs. Après ré-échantillonnage, le c-index ajusté était de 0,69. La calibration interne a retrouvé un bon ajustement entre la survie sans progression prédite et la survie sans progression observée à 24 mois. Un score prédictif a été calculé, permettant d’identifier deux groupes à risque. La durée médiane de la survie sans progression était de 37 mois (intervalle de confiance à 95 % [IC95 %] : 36–55 mois pour le groupe de bas risque et de 8 mois [IC95 % : 5–15 mois] pour le groupe de haut risque, p < 0,01). Conclusion Le MTV est un puissant facteur pronostique de la survie sans progression chez les patients pris en charge par chimioradiothérapie. L’utilisation du MTV pourrait permettre une identification précoce des cancers de pronostic défavorable, candidat potentiel à une intensification thérapeutique. Une validation externe prospective sera nécessaire pour confirmer ces résultats. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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21. THERMAL EFFICIENCY OF STEAM-COOLED REACTORS WITH EXTERNAL FEEDWATER EVAPORATION.
- Author
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Schaer, R
- Published
- 1967
22. Intrauterine position effects in a mouse model of maternal immune activation.
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Schaer R, Mueller FS, Notter T, Weber-Stadlbauer U, and Meyer U
- Subjects
- Animals, Female, Pregnancy, Mice, Male, Cytokines metabolism, Neurodevelopmental Disorders immunology, Behavior, Animal physiology, Fetus immunology, Fetus metabolism, Uterus metabolism, Uterus immunology, Poly I-C pharmacology, Prenatal Exposure Delayed Effects immunology, Prenatal Exposure Delayed Effects metabolism, Disease Models, Animal, Mice, Inbred C57BL, Brain metabolism, Brain immunology
- Abstract
Rodent models of maternal immune activation (MIA) are increasingly used as experimental tools in preclinical research of immune-mediated neurodevelopmental disorders and mental illnesses. Using a viral-like MIA model that is based on prenatal poly(I:C) exposure in mice, we have recently identified the existence of subgroups of MIA-exposed offspring that show dissociable behavioral, transcriptional, brain network and inflammatory profiles even under conditions of genetic homogeneity and identical MIA. Here, we tested the hypothesis that the intrauterine positions of fetuses, which are known to shape individual variability in litter-bearing mammals through variations in fetal hormone exposure, may contribute to the variable outcomes of MIA in mice. MIA was induced by maternal administration of poly(I:C) on gestation day 12 in C57BL/6N mice. Determining intrauterine positions using delivery by Cesarean section (C-section), we found that MIA-exposed offspring developing between female fetuses only (0M-MIA offspring) displayed significant deficits in sociability and sensorimotor gating at adult age, whereas MIA-exposed offspring developing between one or two males in utero (1/2M-MIA offspring) did not show the same deficits. These intrauterine position effects similarly emerged in male and female offspring. Furthermore, while MIA elevated fetal brain levels of pro- and anti-inflammatory cytokines independently of the precise intrauterine position and sex of adjacent fetuses during the acute phase, fetal brain levels of TNF-α remained elevated in 0M-MIA but not 1/2M-MIA offspring until the post-acute phase in late gestation. As expected, 1/2M offspring generally showed higher testosterone levels in the fetal brain during late gestation as compared to 0M offspring, confirming the transfer of testosterone from male fetuses to adjacent male or female fetuses. Taken together, our findings identify a novel source of within-litter variability contributing to heterogeneous outcomes of short- and long-term effects in a mouse model of MIA. In broader context, our findings highlight that individual differences in fetal exposure to hormonal and inflammatory signals may be a perinatal factor that shapes risk and resilience to MIA., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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23. Differential effects of purified low molecular weight Poly(I:C) in the maternal immune activation model depend on the laboratory environment.
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Tillmann KE, Schaer R, Mueller FS, Mueller K, Voelkl B, Weber-Stadlbauer U, and Pollak DD
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- Female, Pregnancy, Animals, Molecular Weight, Disease Models, Animal, Cytokines immunology, Behavior, Animal drug effects, Male, Poly I-C pharmacology, Prenatal Exposure Delayed Effects immunology
- Abstract
The Poly (I:C) (polyriboinosinic-polyribocytidilic acid) paradigm of maternal immune activation (MIA) is most widely used as experimental model for the evaluation of the effects of gestational infection on the brain and behavior of the progeny. We have previously reported significant batch-to-batch variability in the effects of Poly (I:C), purchased from the same supplier (Sigma-Aldrich), on maternal and fetal immune responses and found these differences to be dependent on the relative amount of synthetic double-stranded RNA fragments in the high versus low molecular weight (LMW) range contained in the compound. We here resorted to Poly (I:C) purified for LMW dsRNA fragments to establish a MIA paradigm with increased reproducibility and enhanced standardization in an effort to refine the MIA paradigm and characterize its effect on offspring behavior. We found that the parallel application of LMW Poly (I:C) in two different MIA-experienced laboratories (Vienna and Zurich) yielded differential outcomes in terms of maternal immune responses and behavioral phenotypes in the offspring generation. In both experimental sites, administration of LMW Poly (I:C) induced a significant sickness response and cytokine induction in the pregnant dam and fetal brains, while the expected deficit in sociability as one main behavioral outcome parameter in the MIA progeny, was only present in the Zurich, but not the Vienna cohort. We conclude that although using Poly (I:C) purified for a defined molecular weight range reduces batch-to-batch variability, it does not make the MIA model more reliable and robust. The differential response in behavioral phenotypes of the MIA offspring between the two laboratories illustrates the highly complex interaction between prenatal and postnatal milieus - including the laboratory environment - that determine offspring phenotypic outcomes after MIA. Consequently, establishing a new MIA protocol or implementing the MIA model firstly under new or changed environmental conditions must include the assessment of offspring behavior to ensure solid and reproducible experimental outcomes., (© 2024. The Author(s).)
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- 2024
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24. Prenatal immune activation in mice induces long-term alterations in brain mitochondrial function.
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Schneider Gasser EM, Schaer R, Mueller FS, Bernhardt AC, Lin HY, Arias-Reyes C, and Weber-Stadlbauer U
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- Animals, Female, Pregnancy, Mice, Male, Poly I-C pharmacology, Disease Models, Animal, Brain immunology, Brain metabolism, Amygdala metabolism, Amygdala immunology, Behavior, Animal, Mice, Inbred C57BL, Neurons metabolism, Neurons immunology, Prenatal Exposure Delayed Effects immunology, Mitochondria metabolism, Prefrontal Cortex metabolism, Prefrontal Cortex immunology
- Abstract
Prenatal exposure to infections is a risk factor for neurodevelopmental disorders in offspring, and alterations in mitochondrial function are discussed as a potential underlying factor. Here, using a mouse model of viral-like maternal immune activation (MIA) based on poly(I:C) (POL) treatment at gestational day (GD) 12, we show that adult offspring exhibit behavioral deficits, such as reduced levels of social interaction. In addition, we found increased nicotinamidadenindinucleotid (NADH)- and succinate-linked mitochondrial respiration and maximal electron transfer capacity in the prefrontal cortex (PFC) and in the amygdala (AMY) of males and females. The increase in respiratory capacity resulted from an increase in mitochondrial mass in neurons (as measured by complex IV activity and transcript expression), presumably to compensate for a reduction in mitochondrion-specific respiration. Moreover, in the PFC of control (CON) male offspring a higher excess capacity compared to females was observed, which was significantly reduced in the POL-exposed male offspring, and, along with a higher leak respiration, resulted in a lower mitochondrial coupling efficiency. Transcript expression of the uncoupling proteins (UCP4 and UCP5) showed a reduction in the PFC of POL male mice, suggesting mitochondrial dysfunction. In addition, in the PFC of CON females, a higher expression of the antioxidant enzyme superoxide dismutase (SOD1) was observed, suggesting a higher antioxidant capacity as compared to males. Finally, transcripts analysis of genes involved in mitochondrial biogenesis and dynamics showed reduced expression of fission/fusion transcripts in PFC of POL offspring of both sexes. In conclusion, we show that MIA causes alterations in neuronal mitochondrial function and mass in the PFC and AMY of adult offspring with some effects differing between males and females., (© 2024. The Author(s).)
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- 2024
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25. The Image Biomarker Standardization Initiative: Standardized Convolutional Filters for Reproducible Radiomics and Enhanced Clinical Insights.
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Whybra P, Zwanenburg A, Andrearczyk V, Schaer R, Apte AP, Ayotte A, Baheti B, Bakas S, Bettinelli A, Boellaard R, Boldrini L, Buvat I, Cook GJR, Dietsche F, Dinapoli N, Gabryś HS, Goh V, Guckenberger M, Hatt M, Hosseinzadeh M, Iyer A, Lenkowicz J, Loutfi MAL, Löck S, Marturano F, Morin O, Nioche C, Orlhac F, Pati S, Rahmim A, Rezaeijo SM, Rookyard CG, Salmanpour MR, Schindele A, Shiri I, Spezi E, Tanadini-Lang S, Tixier F, Upadhaya T, Valentini V, van Griethuysen JJM, Yousefirizi F, Zaidi H, Müller H, Vallières M, and Depeursinge A
- Subjects
- Humans, Reproducibility of Results, Biomarkers, Multimodal Imaging, Radiomics, Image Processing, Computer-Assisted
- Abstract
Filters are commonly used to enhance specific structures and patterns in images, such as vessels or peritumoral regions, to enable clinical insights beyond the visible image using radiomics. However, their lack of standardization restricts reproducibility and clinical translation of radiomics decision support tools. In this special report, teams of researchers who developed radiomics software participated in a three-phase study (September 2020 to December 2022) to establish a standardized set of filters. The first two phases focused on finding reference filtered images and reference feature values for commonly used convolutional filters: mean, Laplacian of Gaussian, Laws and Gabor kernels, separable and nonseparable wavelets (including decomposed forms), and Riesz transformations. In the first phase, 15 teams used digital phantoms to establish 33 reference filtered images of 36 filter configurations. In phase 2, 11 teams used a chest CT image to derive reference values for 323 of 396 features computed from filtered images using 22 filter and image processing configurations. Reference filtered images and feature values for Riesz transformations were not established. Reproducibility of standardized convolutional filters was validated on a public data set of multimodal imaging (CT, fluorodeoxyglucose PET, and T1-weighted MRI) in 51 patients with soft-tissue sarcoma. At validation, reproducibility of 486 features computed from filtered images using nine configurations × three imaging modalities was assessed using the lower bounds of 95% CIs of intraclass correlation coefficients. Out of 486 features, 458 were found to be reproducible across nine teams with lower bounds of 95% CIs of intraclass correlation coefficients greater than 0.75. In conclusion, eight filter types were standardized with reference filtered images and reference feature values for verifying and calibrating radiomics software packages. A web-based tool is available for compliance checking., (© RSNA, 2024 See also the editorial by Huisman and D'Antonoli in this issue.)
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- 2024
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26. 3D-printed iodine-ink CT phantom for radiomics feature extraction - advantages and challenges.
- Author
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Bach M, Aberle C, Depeursinge A, Jimenez-Del-Toro O, Schaer R, Flouris K, Konukoglu E, Müller H, Stieltjes B, and Obmann MM
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- Humans, Phantoms, Imaging, Printing, Three-Dimensional, Ink, Tomography, X-Ray Computed methods
- Abstract
Background: To test and validate novel CT techniques, such as texture analysis in radiomics, repeat measurements are required. Current anthropomorphic phantoms lack fine texture and true anatomic representation. 3D-printing of iodinated ink on paper is a promising phantom manufacturing technique. Previously acquired or artificially created CT data can be used to generate realistic phantoms., Purpose: To present the design process of an anthropomorphic 3D-printed iodine ink phantom, highlighting the different advantages and pitfalls in its use. To analyze the phantom's X-ray attenuation properties, and the influences of the printing process on the imaging characteristics, by comparing it to the original input dataset., Methods: Two patient CT scans and artificially generated test patterns were combined in a single dataset for phantom printing and cropped to a size of 26 × 19 × 30 cm
3 . This DICOM dataset was printed on paper using iodinated ink. The phantom was CT-scanned and compared to the original image dataset used for printing the phantom. The water-equivalent diameter of the phantom was compared to that of a patient cohort (N = 104). Iodine concentrations in the phantom were measured using dual-energy CT. 86 radiomics features were extracted from 10 repeat phantom scans and the input dataset. Features were compared using a histogram analysis and a PCA individually and overall, respectively. The frequency content was compared using the normalized spectrum modulus., Results: Low density structures are depicted incorrectly, while soft tissue structures show excellent visual accordance with the input dataset. Maximum deviations of around 30 HU between the original dataset and phantom HU values were observed. The phantom has X-ray attenuation properties comparable to a lightweight adult patient (∼54 kg, BMI 19 kg/m2 ). Iodine concentrations in the phantom varied between 0 and 50 mg/ml. PCA of radiomics features shows different tissue types separate in similar areas of PCA representation in the phantom scans as in the input dataset. Individual feature analysis revealed systematic shift of first order radiomics features compared to the original dataset, while some higher order radiomics features did not. The normalized frequency modulus |f(ω)| of the phantom data agrees well with the original data. However, all frequencies systematically occur more frequently in the phantom compared to the maximum of the spectrum modulus than in the original data set, especially for mid-frequencies (e.g., for ω = 0.3942 mm-1 , |f(ω)|original = 0.09 * |fmax |original and |f(ω)|phantom = 0.12 * |fmax |phantom )., Conclusions: 3D-iodine-ink-printing technology can be used to print anthropomorphic phantoms with a water-equivalent diameter of a lightweight adult patient. Challenges include small residual air enclosures and the fidelity of HU values. For soft tissue, there is a good agreement between the HU values of the phantom and input data set. Radiomics texture features of the phantom scans are similar to the input data set, but systematic shifts of radiomics features in first order features, due to differences in HU values, need to be considered. The paper substrate influences the spatial frequency distribution of the phantom scans. This phantom type is of very limited use for dual-energy CT analyses., (© 2023 The Authors. Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.)- Published
- 2023
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27. QuantImage v2: a comprehensive and integrated physician-centered cloud platform for radiomics and machine learning research.
- Author
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Abler D, Schaer R, Oreiller V, Verma H, Reichenbach J, Aidonopoulos O, Evéquoz F, Jreige M, Prior JO, and Depeursinge A
- Subjects
- Research, Software, Models, Theoretical, Forecasting, Carcinoma diagnostic imaging, Lung Neoplasms diagnostic imaging, Humans, Machine Learning, Radiology instrumentation, Radiology methods, Computational Biology, Cloud Computing
- Abstract
Background: Radiomics, the field of image-based computational medical biomarker research, has experienced rapid growth over the past decade due to its potential to revolutionize the development of personalized decision support models. However, despite its research momentum and important advances toward methodological standardization, the translation of radiomics prediction models into clinical practice only progresses slowly. The lack of physicians leading the development of radiomics models and insufficient integration of radiomics tools in the clinical workflow contributes to this slow uptake., Methods: We propose a physician-centered vision of radiomics research and derive minimal functional requirements for radiomics research software to support this vision. Free-to-access radiomics tools and frameworks were reviewed to identify best practices and reveal the shortcomings of existing software solutions to optimally support physician-driven radiomics research in a clinical environment., Results: Support for user-friendly development and evaluation of radiomics prediction models via machine learning was found to be missing in most tools. QuantImage v2 (QI2) was designed and implemented to address these shortcomings. QI2 relies on well-established existing tools and open-source libraries to realize and concretely demonstrate the potential of a one-stop tool for physician-driven radiomics research. It provides web-based access to cohort management, feature extraction, and visualization and supports "no-code" development and evaluation of machine learning models against patient-specific outcome data., Conclusions: QI2 fills a gap in the radiomics software landscape by enabling "no-code" radiomics research, including model validation, in a clinical environment. Further information about QI2, a public instance of the system, and its source code is available at https://medgift.github.io/quantimage-v2-info/ . Key points As domain experts, physicians play a key role in the development of radiomics models. Existing software solutions do not support physician-driven research optimally. QuantImage v2 implements a physician-centered vision for radiomics research. QuantImage v2 is a web-based, "no-code" radiomics research platform., (© 2023. The Author(s).)
- Published
- 2023
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28. Late prenatal immune activation in mice induces transgenerational effects via the maternal and paternal lineages.
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Raymann S, Schalbetter SM, Schaer R, Bernhardt AC, Mueller FS, Meyer U, and Weber-Stadlbauer U
- Subjects
- Animals, Female, Pregnancy, Disease Models, Animal, Epigenesis, Genetic, Poly I-C, Mice, Brain, Cognition, Prenatal Exposure Delayed Effects, Immune System Phenomena
- Abstract
Prenatal exposure to infectious or noninfectious immune activation is an environmental risk factor for neurodevelopmental disorders and mental illnesses. Recent research using animal models suggests that maternal immune activation (MIA) during early to middle stages of pregnancy can induce transgenerational effects on brain and behavior, likely via inducing stable epigenetic modifications across generations. Using a mouse model of viral-like MIA, which is based on gestational treatment with poly(I:C), the present study explored whether transgenerational effects can also emerge when MIA occurs in late pregnancy. Our findings demonstrate that the direct descendants born to poly(I:C)-treated mothers display deficits in temporal order memory, which are similarly present in second- and third-generation offspring. These transgenerational effects were mediated via both the maternal and paternal lineages and were accompanied by transient changes in maternal care. In addition to the cognitive effects, late prenatal immune activation induced generation-spanning effects on the prefrontal expression of gamma-aminobutyric acid (GABA)ergic genes, including parvalbumin and distinct alpha-subunits of the GABAA receptor. Together, our results suggest that MIA in late pregnancy has the potential to affect cognitive functions and prefrontal gene expression patterns in multiple generations, highlighting its role in shaping disease risk across generations., (© The Author(s) 2022. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
- Full Text
- View/download PDF
29. Assessing radiomics feature stability with simulated CT acquisitions.
- Author
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Flouris K, Jimenez-Del-Toro O, Aberle C, Bach M, Schaer R, Obmann MM, Stieltjes B, Müller H, Depeursinge A, and Konukoglu E
- Subjects
- Phantoms, Imaging, Retrospective Studies, Machine Learning, Tomography, X-Ray Computed methods
- Abstract
Medical imaging quantitative features had once disputable usefulness in clinical studies. Nowadays, advancements in analysis techniques, for instance through machine learning, have enabled quantitative features to be progressively useful in diagnosis and research. Tissue characterisation is improved via the "radiomics" features, whose extraction can be automated. Despite the advances, stability of quantitative features remains an important open problem. As features can be highly sensitive to variations of acquisition details, it is not trivial to quantify stability and efficiently select stable features. In this work, we develop and validate a Computed Tomography (CT) simulator environment based on the publicly available ASTRA toolbox ( www.astra-toolbox.com ). We show that the variability, stability and discriminative power of the radiomics features extracted from the virtual phantom images generated by the simulator are similar to those observed in a tandem phantom study. Additionally, we show that the variability is matched between a multi-center phantom study and simulated results. Consequently, we demonstrate that the simulator can be utilised to assess radiomics features' stability and discriminative power., (© 2022. The Author(s).)
- Published
- 2022
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30. High Triplet Energy Iridium(III) Isocyanoborato Complex for Photochemical Upconversion, Photoredox and Energy Transfer Catalysis.
- Author
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Schmid L, Glaser F, Schaer R, and Wenger OS
- Abstract
Cyclometalated Ir(III) complexes are often chosen as catalysts for challenging photoredox and triplet-triplet-energy-transfer (TTET) catalyzed reactions, and they are of interest for upconversion into the ultraviolet spectral range. However, the triplet energies of commonly employed Ir(III) photosensitizers are typically limited to values around 2.5-2.75 eV. Here, we report on a new Ir(III) luminophore, with an unusually high triplet energy near 3.0 eV owing to the modification of a previously reported Ir(III) complex with isocyanoborato ligands. Compared to a nonborylated cyanido precursor complex, the introduction of B(C
6 F5 )3 units in the second coordination sphere results in substantially improved photophysical properties, in particular a high luminescence quantum yield (0.87) and a long excited-state lifetime (13.0 μs), in addition to the high triplet energy. These favorable properties (including good long-term photostability) facilitate exceptionally challenging organic triplet photoreactions and (sensitized) triplet-triplet annihilation upconversion to a fluorescent singlet excited state beyond 4 eV, unusually deep in the ultraviolet region. The new Ir(III) complex photocatalyzes a sigmatropic shift and [2 + 2] cycloaddition reactions that are unattainable with common transition metal-based photosensitizers. In the presence of a sacrificial electron donor, it furthermore is applicable to demanding photoreductions, including dehalogenations, detosylations, and the degradation of a lignin model substrate. Our study demonstrates how rational ligand design of transition-metal complexes (including underexplored second coordination sphere effects) can be used to enhance their photophysical properties and thereby broaden their application potential in solar energy conversion and synthetic photochemistry.- Published
- 2022
- Full Text
- View/download PDF
31. Machine Learning Assisted Citation Screening for Systematic Reviews.
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Dhrangadhariya A, Hilfiker R, Schaer R, and Müller H
- Subjects
- Humans, Research, Machine Learning, Mass Screening
- Abstract
Evidence-based practice is highly dependent upon up-to-date systematic reviews (SR) for decision making. However, conducting and updating systematic reviews, especially the citation screening for identification of relevant studies, requires much human work and is therefore expensive. Automating citation screening using machine learning (ML) based approaches can reduce cost and labor. Machine learning has been applied to automate citation screening but not for the SRs with very narrow research questions. This paper reports the results and observations for an ongoing research that aims to automate citation screening for SRs with narrow research questions using machine learning. The research also sheds light on the problem of class imbalance and class overlap on the performance of ML classifiers when applied to SRs with narrow research questions.
- Published
- 2020
- Full Text
- View/download PDF
32. Deep Learning-Based Retrieval System for Gigapixel Histopathology Cases and the Open Access Literature.
- Author
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Schaer R, Otálora S, Jimenez-Del-Toro O, Atzori M, and Müller H
- Abstract
Background: The introduction of digital pathology into clinical practice has led to the development of clinical workflows with digital images, in connection with pathology reports. Still, most of the current work is time-consuming manual analysis of image areas at different scales. Links with data in the biomedical literature are rare, and a need for search based on visual similarity within whole slide images (WSIs) exists., Objectives: The main objective of the work presented is to integrate content-based visual retrieval with a WSI viewer in a prototype. Another objective is to connect cases analyzed in the viewer with cases or images from the biomedical literature, including the search through visual similarity and text., Methods: An innovative retrieval system for digital pathology is integrated with a WSI viewer, allowing to define regions of interest (ROIs) in images as queries for finding visually similar areas in the same or other images and to zoom in/out to find structures at varying magnification levels. The algorithms are based on a multimodal approach, exploiting both text information and content-based image features., Results: The retrieval system allows viewing WSIs and searching for regions that are visually similar to manually defined ROIs in various data sources (proprietary and public datasets, e.g., scientific literature). The system was tested by pathologists, highlighting its capabilities and suggesting ways to improve it and make it more usable in clinical practice., Conclusions: The developed system can enhance the practice of pathologists by enabling them to use their experience and knowledge to control artificial intelligence tools for navigating repositories of images for clinical decision support and teaching, where the comparison with visually similar cases can help to avoid misinterpretations. The system is available as open source, allowing the scientific community to test, ideate and develop similar systems for research and clinical practice., Competing Interests: There are no conflicts of interest.
- Published
- 2019
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33. Cloud-Based Evaluation of Anatomical Structure Segmentation and Landmark Detection Algorithms: VISCERAL Anatomy Benchmarks.
- Author
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Jimenez-Del-Toro O, Muller H, Krenn M, Gruenberg K, Taha AA, Winterstein M, Eggel I, Foncubierta-Rodriguez A, Goksel O, Jakab A, Kontokotsios G, Langs G, Menze BH, Salas Fernandez T, Schaer R, Walleyo A, Weber MA, Dicente Cid Y, Gass T, Heinrich M, Jia F, Kahl F, Kechichian R, Mai D, Spanier AB, Vincent G, Wang C, Wyeth D, and Hanbury A
- Subjects
- Aged, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Tomography, X-Ray Computed, Algorithms, Anatomic Landmarks diagnostic imaging, Anatomy methods, Image Processing, Computer-Assisted methods
- Abstract
Variations in the shape and appearance of anatomical structures in medical images are often relevant radiological signs of disease. Automatic tools can help automate parts of this manual process. A cloud-based evaluation framework is presented in this paper including results of benchmarking current state-of-the-art medical imaging algorithms for anatomical structure segmentation and landmark detection: the VISCERAL Anatomy benchmarks. The algorithms are implemented in virtual machines in the cloud where participants can only access the training data and can be run privately by the benchmark administrators to objectively compare their performance in an unseen common test set. Overall, 120 computed tomography and magnetic resonance patient volumes were manually annotated to create a standard Gold Corpus containing a total of 1295 structures and 1760 landmarks. Ten participants contributed with automatic algorithms for the organ segmentation task, and three for the landmark localization task. Different algorithms obtained the best scores in the four available imaging modalities and for subsets of anatomical structures. The annotation framework, resulting data set, evaluation setup, results and performance analysis from the three VISCERAL Anatomy benchmarks are presented in this article. Both the VISCERAL data set and Silver Corpus generated with the fusion of the participant algorithms on a larger set of non-manually-annotated medical images are available to the research community.
- Published
- 2016
- Full Text
- View/download PDF
34. Comparing fusion techniques for the ImageCLEF 2013 medical case retrieval task.
- Author
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G Seco de Herrera A, Schaer R, Markonis D, and Müller H
- Subjects
- Algorithms, Artificial Intelligence, Documentation methods, Pattern Recognition, Automated methods, Terminology as Topic, User-Computer Interface, Information Storage and Retrieval methods, Multimodal Imaging methods, Natural Language Processing, Radiology Information Systems organization & administration, Subtraction Technique, Vocabulary, Controlled
- Abstract
Retrieval systems can supply similar cases with a proven diagnosis to a new example case under observation to help clinicians during their work. The ImageCLEFmed evaluation campaign proposes a framework where research groups can compare case-based retrieval approaches. This paper focuses on the case-based task and adds results of the compound figure separation and modality classification tasks. Several fusion approaches are compared to identify the approaches best adapted to the heterogeneous data of the task. Fusion of visual and textual features is analyzed, demonstrating that the selection of the fusion strategy can improve the best performance on the case-based retrieval task., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2015
- Full Text
- View/download PDF
35. Live ECG readings using Google Glass in emergency situations.
- Author
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Schaer R, Salamin F, Jimenez Del Toro OA, Atzori M, Muller H, and Widmer A
- Subjects
- Adult, Emergency Treatment, Eyeglasses, Female, Heart Diseases physiopathology, Heart Diseases surgery, Humans, Male, Medical Staff, Microcomputers, Monitoring, Physiologic instrumentation, Electrocardiography, Monitoring, Physiologic methods
- Abstract
Most sudden cardiac problems require rapid treatment to preserve life. In this regard, electrocardiograms (ECG) shown on vital parameter monitoring systems help medical staff to detect problems. In some situations, such monitoring systems may display information in a less than convenient way for medical staff. For example, vital parameters are displayed on large screens outside the field of view of a surgeon during cardiac surgery. This may lead to losing time and to mistakes when problems occur during cardiac operations. In this paper we present a novel approach to display vital parameters such as the second derivative of the ECG rhythm and heart rate close to the field of view of a surgeon using Google Glass. As a preliminary assessment, we run an experimental study to verify the possibility for medical staff to identify abnormal ECG rhythms from Google Glass. This study compares 6 ECG rhythms readings from a 13.3 inch laptop screen and from the prism of Google Glass. Seven medical residents in internal medicine participated in the study. The preliminary results show that there is no difference between identifying these 6 ECG rhythms from the laptop screen versus Google Glass. Both allow close to perfect identification of the 6 common ECG rhythms. This shows the potential of connected glasses such as Google Glass to be useful in selected medical applications.
- Published
- 2015
- Full Text
- View/download PDF
36. Facilitating medical information search using Google Glass connected to a content-based medical image retrieval system.
- Author
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Widmer A, Schaer R, Markonis D, and Muller H
- Subjects
- Brain pathology, Humans, Image Processing, Computer-Assisted, Lung diagnostic imaging, Magnetic Resonance Imaging, Tomography, X-Ray Computed, Eyeglasses, Information Storage and Retrieval methods, Medical Informatics methods, Search Engine
- Abstract
Wearable computing devices are starting to change the way users interact with computers and the Internet. Among them, Google Glass includes a small screen located in front of the right eye, a camera filming in front of the user and a small computing unit. Google Glass has the advantage to provide online services while allowing the user to perform tasks with his/her hands. These augmented glasses uncover many useful applications, also in the medical domain. For example, Google Glass can easily provide video conference between medical doctors to discuss a live case. Using these glasses can also facilitate medical information search by allowing the access of a large amount of annotated medical cases during a consultation in a non-disruptive fashion for medical staff. In this paper, we developed a Google Glass application able to take a photo and send it to a medical image retrieval system along with keywords in order to retrieve similar cases. As a preliminary assessment of the usability of the application, we tested the application under three conditions (images of the skin; printed CT scans and MRI images; and CT and MRI images acquired directly from an LCD screen) to explore whether using Google Glass affects the accuracy of the results returned by the medical image retrieval system. The preliminary results show that despite minor problems due to the relative stability of the Google Glass, images can be sent to and processed by the medical image retrieval system and similar images are returned to the user, potentially helping in the decision making process.
- Published
- 2014
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- View/download PDF
37. Calretinin regulates Ca2+-dependent inactivation and facilitation of Ca(v)2.1 Ca2+ channels through a direct interaction with the α12.1 subunit.
- Author
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Christel CJ, Schaer R, Wang S, Henzi T, Kreiner L, Grabs D, Schwaller B, and Lee A
- Subjects
- Animals, Calbindin 2, Calcium Channels, N-Type genetics, Cerebellum cytology, HEK293 Cells, Humans, Mice, Nerve Tissue Proteins genetics, Neurons cytology, Protein Structure, Tertiary, S100 Calcium Binding Protein G genetics, Calcium metabolism, Calcium Channels, N-Type metabolism, Calcium Signaling physiology, Cerebellum metabolism, Nerve Tissue Proteins metabolism, Neurons metabolism, S100 Calcium Binding Protein G metabolism
- Abstract
Voltage-gated Ca(v)2.1 Ca(2+) channels undergo dual modulation by Ca(2+), Ca(2+)-dependent inactivation (CDI), and Ca(2+)-dependent facilitation (CDF), which can influence synaptic plasticity in the nervous system. Although the molecular determinants controlling CDI and CDF have been the focus of intense research, little is known about the factors regulating these processes in neurons. Here, we show that calretinin (CR), a Ca(2+)-binding protein highly expressed in subpopulations of neurons in the brain, inhibits CDI and enhances CDF by binding directly to α(1)2.1. Screening of a phage display library with CR as bait revealed a highly basic CR-binding domain (CRB) present in multiple copies in the cytoplasmic linker between domains II and III of α(1)2.1. In pulldown assays, CR binding to fusion proteins containing these CRBs was largely Ca(2+)-dependent. α(1)2.1 coimmunoprecipitated with CR antibodies from transfected cells and mouse cerebellum, which confirmed the existence of CR-Ca(v)2.1 complexes in vitro and in vivo. In HEK293T cells, CR significantly decreased Ca(v)2.1 CDI and increased CDF. CR binding to α(1)2.1 was required for these effects, because they were not observed upon substitution of the II-III linker of α(1)2.1 with that from the Ca(v)1.2 α(1) subunit (α(1)1.2), which lacks the CRBs. In addition, coexpression of a protein containing the CRBs blocked the modulatory action of CR, most likely by competing with CR for interactions with α(1)2.1. Our findings highlight an unexpected role for CR in directly modulating effectors such as Ca(v)2.1, which may have major consequences for Ca(2+) signaling and neuronal excitability.
- Published
- 2012
- Full Text
- View/download PDF
38. Hepatitis B virus prevalence and vaccination response in health care workers and students at the Federal University of Bahia, Brazil.
- Author
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Carvalho P, Schinoni MI, Andrade J, Vasconcelos Rêgo MA, Marques P, Meyer R, Araújo A, Menezes T, Oliveira C, Macêdo RS, Macêdo LS, Leal JC, Matos B, Schaer R, Simones JM, Freire SM, and Paraná R
- Subjects
- Adolescent, Adult, Aged, Antibodies, Viral blood, Brazil epidemiology, Cross-Sectional Studies, Female, Hepatitis B Core Antigens immunology, Hepatitis B Surface Antigens blood, Humans, Male, Middle Aged, Occupational Exposure, Seroepidemiologic Studies, Treatment Outcome, Young Adult, Health Personnel, Hepatitis B epidemiology, Hepatitis B prevention & control, Hepatitis B Vaccines therapeutic use, Hepatitis B virus immunology, Students, Universities
- Abstract
Unlabelled: BACKGROUND AND RATIONALE FOR THE STUDY: Hepatitis B (HB) is one of the most prevalent occupational infections in health attendance environments. According to the Brazil Ministry of Health, health professionals must be vaccinated against the hepatitis B virus (HBV) and provide laboratory proof of immunization., Aims: To evaluate the seroprevalence of HBV infection and to analyze the response to vaccine by measuring serum antibodies against HBV surface antigen (anti-HBs) levels in a sample of students and health professionals at the Federal University of Bahia., Results: As part of this cross-sectional study, a campaign against occupational HB was launched in 2007 and vaccination and blood samples were collected for analysis of the following serological markers: HBV surface antigen (HBsAg) and anti-HBs (measured by enzyme-linked immunoassay) and total antibodies against HBV core antigen (anti-HBc). The study sample comprised 766 people. Global seropositivity for HBV was 1.7%: 0.5% in the students and 8.8% in the professionals. In a group of volunteers, a serological profile compatible with postvaccine immunity was shown by 95% of volunteers with proof of vaccination and by 81.8% of volunteers without proof of vaccination., Conclusions: In conclusion, this study shows that it is important to promote vaccination campaigns and improve knowledge and awareness about HB among health care workers and higher education students.
- Published
- 2012
39. Flavonoids inhibit angiogenic cytokine production by human glioma cells.
- Author
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Freitas S, Costa S, Azevedo C, Carvalho G, Freire S, Barbosa P, Velozo E, Schaer R, Tardy M, Meyer R, and Nascimento I
- Subjects
- Antibodies, Monoclonal pharmacology, Antibodies, Monoclonal, Humanized, Bevacizumab, Croton chemistry, Fabaceae chemistry, Glioblastoma blood supply, Humans, Neovascularization, Pathologic metabolism, Phytotherapy, Angiogenesis Inhibitors pharmacology, Cytokines antagonists & inhibitors, Cytokines biosynthesis, Flavonoids pharmacology, Glioblastoma drug therapy, Glioblastoma metabolism, Plant Extracts pharmacology
- Abstract
VEGF and TGF-β1 are cytokines that stimulate tissue invasion and angiogenesis. These factors are considered as molecular targets for the therapy of glioblastoma. Bevacizumab, a recombinant humanized monoclonal antibody developed against VEGF, inhibits endothelial cell proliferation and vessel formation. Flavonoids obtained from Dimorphandra mollis and Croton betulaster have been described as proliferation inhibitors of a human glioblastoma derived cell line. VEGF and TGF-β1 levels were dosed by ELISA in a GL-15 cell line treated with bevacizumab and also with the flavonoids rutin, 5-hydroxy-7,4'-dimethoxyflavone, casticin, apigenin and penduletin. Rutin reduced the VEGF and TGF-β1 levels after 24 h but not after 72 h. The other flavonoids significantly reduced TGF-β1 production. Bevacizumab reduced only the VEGF levels in the supernatant from GL-15 cultures. These results suggest that the flavonoids studied, and commonly used in popular medicine, present an interesting subject of study due to their potential effect as angiogenic factor inhibitors., (Copyright © 2010 John Wiley & Sons, Ltd.)
- Published
- 2011
- Full Text
- View/download PDF
40. The flavonoid rutin but not the alkaloid arborinine induces apoptosis in a B-cell hybridoma cell line.
- Author
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Roseghini R, Falcão GM, Oliveira Costa JF, Clarêncio J, Nascimento I, Velozo E, Schaer R, Vale V, Costa SL, Costa Mde F, Tardy M, Meyer R, and Menezes Freire S
- Subjects
- Acridines isolation & purification, Animals, Antibodies, Monoclonal biosynthesis, B-Lymphocytes, Cell Line, Tumor, Cell Proliferation drug effects, Hybridomas drug effects, Hybridomas pathology, Mice, Necrosis chemically induced, Rutin isolation & purification, Seeds, Acridines pharmacology, Antineoplastic Agents, Phytogenic pharmacology, Apoptosis drug effects, Fabaceae chemistry, Plant Extracts pharmacology, Rutaceae chemistry, Rutin pharmacology
- Abstract
The effects of arborinine, an alkaloid extracted from Erthela bahiensis and of rutin, a flavonoid obtained from Dimorphandra mollis (Benth.), Brazilian medicinal plants, on the viability and function of a murine B-cell hybridoma as a tumor model were investigated. The flavonoid rutin at 50 microM induced an increase in the number of apoptotic cells of one- to fivefold and reductions in cellular proliferation and monoclonal antibody production. Less but still significant necrosis was also induced by rutin under the same experimental conditions. On the other hand, the alkaloid arborinine exerted no significant effects on the studied parameters.
- Published
- 2009
- Full Text
- View/download PDF
41. A novel method for analyzing DSCE-images with an application to tumor grading.
- Author
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Slotboom J, Schaer R, Ozdoba C, Reinert M, Vajtai I, El-Koussy M, Kiefer C, Zbinden M, Schroth G, and Wiest R
- Subjects
- Adult, Aged, Brain Neoplasms classification, Contrast Media, Female, Glioma classification, Humans, Male, Middle Aged, Reproducibility of Results, Sensitivity and Specificity, Algorithms, Brain Neoplasms diagnosis, Glioma diagnosis, Image Enhancement methods, Image Interpretation, Computer-Assisted methods, Organometallic Compounds
- Abstract
Objectives: (a) The development of a novel analysis method, named Dynamic pixel intensity Histogram Analysis (DHA) allowing for pixel intensity-histogram-model-parameter fitting of arbitrary-shaped regions defined in dynamic-susceptibility-contrast-enhanced (DSCE) difference MR-image time-series, and (b) its prospective application and evaluation for glioma grading., Materials and Methods: For each difference-image, pixel intensity histograms of arbitrary-shaped ROIs were computed and fitted using the Levenberg-Marquardt algorithm. Time-dependent histogram center-position- and width-parameters are computed during bolus-passage. The method was applied to 25 patients with low and high grade gliomas., Results: During bolus outflow-time, histogram-center-position-parameter and histogram-width-parameter reach highest significance levels and discriminate gliomas of different grades. The histogram center-position-parameter discriminated grade-II from grade-III, grade-II from grade-IV but not grade-III from grade-IV. The observed histogram width-parameters discriminated grade-II from grade-III (P < 0.00022), grade-II from grade-IV (P <8.3 10), and grade-III from grade-IV (P < 0.00063)., Conclusions: DHA is a easy-to-use method for glioma grading; the histogram width parameter is best indicator for histologic grade.
- Published
- 2008
- Full Text
- View/download PDF
42. Serologic immunoreactivity to Neospora caninum antigens in dogs determined by indirect immunofluorescence, western blotting and dot-ELISA.
- Author
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Pinheiro AM, Costa MF, Paule B, Vale V, Ribeiro M, Nascimento I, Schaer RE, Almeida MA, Meyer R, and Freire SM
- Subjects
- Animals, Antibodies, Protozoan blood, Blotting, Western, Coccidiosis diagnosis, Coccidiosis immunology, Coccidiosis parasitology, Cross Reactions, Dog Diseases diagnosis, Dog Diseases immunology, Dogs, Enzyme-Linked Immunosorbent Assay methods, Female, Fluorescent Antibody Technique, Indirect veterinary, Male, Neospora immunology, Sensitivity and Specificity, Toxoplasma isolation & purification, Toxoplasmosis, Animal diagnosis, Coccidiosis veterinary, Dog Diseases parasitology, Enzyme-Linked Immunosorbent Assay veterinary, Neospora isolation & purification
- Abstract
Neospora caninum, is a coccidian protozoan known as a major cause of bovine abortion and canine neuropathies. The aim of the present study was to develop a reliable and quick test to detect antibodies to N. caninum in dog sera. Sixty-five serum samples from dogs, including 35 positive and 30 negative for N. caninum antibodies were used for standardization of the test. In parallel, immunoreactivity of the sera to Toxoplasma gondii antigens was investigated using a passive agglutination test. A dot-ELISA test, using soluble extract of N. caninum tachyzoites on nitrocellulose ester membranes, was developed and standardized. SDS-PAGE and complementary analysis of reactivity by Western blotting were used for the characterization of the immunoreactive fractions of all tested sera. The sensitivity and specificity of the dot-ELISA were 94 and 73%, respectively, compared to IFAT at a cut-off of 1:50, and 87 and 100% compared to IFAT at a cut-off of 1:25. Among the sera that tested positively for both IFAT and dot-ELISA, only 8.6% were reactive to T. gondii. The most immunoreactive fractions in Western blots were the 14-, 33-, 42- and 55 kDa bands, with percentages of 42, 60, 42 and 37%, respectively. The 60 kDa band showed a non-specific reaction in 43% of neosporosis-negative animals by both dot-ELISA and IFAT. These results indicate that the dot-ELISA using N. caninum antigen present good sensitivity and specificity, and might be used as a screening test to detect antibodies to N. caninum in dogs.
- Published
- 2005
- Full Text
- View/download PDF
43. Experimental Corynebacterium pseudotuberculosis primary infection in goats: kinetics of IgG and interferon-gamma production, IgG avidity and antigen recognition by Western blotting.
- Author
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Paule BJ, Azevedo V, Regis LF, Carminati R, Bahia CR, Vale VL, Moura-Costa LF, Freire SM, Nascimento I, Schaer R, Goes AM, and Meyer R
- Subjects
- Animals, Antibodies, Bacterial blood, Antibody Affinity immunology, Antigens, Bacterial immunology, Blotting, Western veterinary, Brazil, Corynebacterium Infections immunology, Corynebacterium Infections pathology, Enzyme-Linked Immunosorbent Assay veterinary, Female, Goat Diseases microbiology, Goats, Immunoglobulin G blood, Immunoglobulin G immunology, Interferon-gamma blood, Kinetics, Lymphadenitis immunology, Lymphadenitis pathology, Male, Corynebacterium Infections veterinary, Corynebacterium pseudotuberculosis immunology, Goat Diseases immunology, Immunoglobulin G biosynthesis, Interferon-gamma biosynthesis, Lymphadenitis veterinary
- Abstract
Corynebacterium pseudotuberculosis is the cause of caseous lymphadenitis (CLA) in small ruminants, a chronic granulomatous disease that provokes significant zootechnics losses to ovine and goat breeders in northern Brazil. The present work was conducted to analyse aspects of humoral and cellular immune responses after experimental infection. Eight goats were infected intradermally with a single dose of virulent C. pseudotuberculosis strain and specific IgG, interferon-gamma (IFN-gamma) production as well as IgG avidity and antigens pattern recognition dynamics against an excreted-secreted antigen were recorded during 20 weeks. At the end of the follow-up, animals were slaughtered and necropsied. Although no animals showed apparent clinical signs of infection at the end of the trial, IFN-gamma response, even more so than the humoral response, differentiated animals into two groups of high or medium/low response. The time-course of IFN-gamma production presented a short-lived primary response on day 5 after infection of animals of both groups, and a strong and long lasting secondary response starting on day 16 after infection in the high response group. The indirect ELISA used was able to detect a positive antibody titre between 6 and 11 days after infection in the two groups. IgG avidity index oscillated initially between 15 and 45%, and showed approximately 5% units increment during the 20 follow-up weeks. With only one individual exception, the qualitative antigens pattern recognition showed on day 11 after infection remained constant through the experiment. IgG avidity is highly correlated with IgG production, but could not be related with specific immunodominant bands. Both humoral and cellular responses kinetics presented a similar pattern of activation/deactivation but necropsy results suggested that the IFN-gamma test would be a very specific marker of CLA status.
- Published
- 2003
- Full Text
- View/download PDF
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