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Smith HB, Mathis C. Life detection in a universe of false positives: Can the Fatal Flaws of Exoplanet Biosignatures be Overcome Absent a Theory of Life? Bioessays 2023; 45:e2300050. [PMID: 37821360 DOI: 10.1002/bies.202300050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 09/24/2023] [Accepted: 09/27/2023] [Indexed: 10/13/2023]
Abstract
Astrobiology aims to determine the distribution and diversity of life in the universe. But as the word "biosignature" suggests, what will be detected is not life itself, but an observation implicating living systems. Our limited access to other worlds suggests this observation is more likely to reflect out-of-equilibrium gasses than a writhing octopus. Yet, anything short of a writhing octopus will raise skepticism about what has been detected. Resolving that skepticism requires a theory to delineate processes due to life and those due to abiotic mechanisms. This poses an existential question for life detection: How do astrobiologists plan to detect life on exoplanets via features shared between non-living and living systems? We argue that you cannot without an underlying theory of life. We illustrate this by analyzing the hypothetical detection of an "Earth 2.0" exoplanet. Without a theory of life, we argue the community should focus on identifying unambiguous features of life via four areas: examining life on Earth, building life in the lab, probing the solar system, and searching for technosignatures. Ultimately, we ask, what exactly do astrobiologists hope to learn by searching for life?
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Affiliation(s)
- Harrison B Smith
- Earth-Life Science Institute, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, Japan
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Cole Mathis
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
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2
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Foote S, Sinhadc P, Mathis C, Walker SI. False Positives and the Challenge of Testing the Alien Hypothesis. Astrobiology 2023; 23:1189-1201. [PMID: 37962842 DOI: 10.1089/ast.2023.0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The origin of life and the detection of alien life have historically been treated as separate scientific research problems. However, they are not strictly independent. Here, we discuss the need for a better integration of the sciences of life detection and origins of life. Framing these dual problems within the formalism of Bayesian hypothesis testing, we demonstrate via simple examples how high confidence in life detection claims require either (1) a strong prior hypothesis about the existence of life in a particular alien environment, or conversely, (2) signatures of life that are not susceptible to false positives. As a case study, we discuss the role of priors and hypothesis testing in recent results reporting potential detection of life in the venusian atmosphere and in the icy plumes of Enceladus. While many current leading biosignature candidates are subject to false positives because they are not definitive of life, our analyses demonstrate why it is necessary to shift focus to candidate signatures that are definitive. This indicates a necessity to develop methods that lack substantial false positives, by using observables for life that rely on prior hypotheses with strong theoretical and empirical support in identifying defining features of life. Abstract theories developed in pursuit of understanding universal features of life are more likely to be definitive and to apply to life-as-we-don't-know-it. We discuss Molecular Assembly theory as an example of such an observable which is applicable to life detection within the solar system. In the absence of alien examples these are best validated in origin of life experiments, substantiating the need for better integration between origins of life and biosignature science research communities. This leads to a conclusion that extraordinary claims in astrobiology (e.g., definitive detection of alien life) require extraordinary explanations, whereas the evidence itself could be quite ordinary.
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Affiliation(s)
- Searra Foote
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
| | - Pritvik Sinhadc
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Dubai College, Dubai, UAE
| | - Cole Mathis
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
| | - Sara Imari Walker
- School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, Arizona, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
- Blue Marble Space Institute for Science, Seattle, Washington, USA
- ASU-SFI Center for Biosocial Complex Systems, Arizona State University, Tempe, Arizona, USA
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Mettler C, Beeker N, Mathis C, Treluyer J, Le Guern V, Chouchana L, Terrier B. La survenue d’une naissance prématurée chez les femmes enceintes atteintes de vascularite systémique: une étude de cohorte nationale. Rev Med Interne 2021. [DOI: 10.1016/j.revmed.2021.10.256] [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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Mettler C, Beeker N, Mathis C, Treluyer J, Le Guern V, Chouchana L, Terrier B. Utilisation des traitements immunosuppresseurs pendant la grossesse chez les femmes atteintes de vascularite systémique : une étude de cohorte nationale. Rev Med Interne 2021. [DOI: 10.1016/j.revmed.2021.10.257] [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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Liu Y, Mathis C, Bajczyk MD, Marshall SM, Wilbraham L, Cronin L. Exploring and mapping chemical space with molecular assembly trees. Sci Adv 2021; 7:eabj2465. [PMID: 34559562 PMCID: PMC8462901 DOI: 10.1126/sciadv.abj2465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/03/2021] [Indexed: 06/01/2023]
Abstract
The rule-based search of chemical space can generate an almost infinite number of molecules, but exploration of known molecules as a function of the minimum number of steps needed to build up the target graphs promises to uncover new motifs and transformations. Assembly theory is an approach to compare the intrinsic complexity and properties of molecules by the minimum number of steps needed to build up the target graphs. Here, we apply this approach to prebiotic chemistry, gene sequences, plasticizers, and opiates. This allows us to explore molecules connected to the assembly tree, rather than the entire space of molecules possible. Last, by developing a reassembly method, based on assembly trees, we found that in the case of the opiates, a new set of drug candidates could be generated that would not be accessible via conventional fragment-based drug design, thereby demonstrating how this approach might find application in drug discovery.
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Affiliation(s)
- Yu Liu
- School of Chemistry, University of Glasgow, University Avenue,
Glasgow G12 8QQ, UK
| | - Cole Mathis
- School of Chemistry, University of Glasgow, University Avenue,
Glasgow G12 8QQ, UK
| | | | - Stuart M. Marshall
- School of Chemistry, University of Glasgow, University Avenue,
Glasgow G12 8QQ, UK
| | - Liam Wilbraham
- School of Chemistry, University of Glasgow, University Avenue,
Glasgow G12 8QQ, UK
| | - Leroy Cronin
- School of Chemistry, University of Glasgow, University Avenue,
Glasgow G12 8QQ, UK
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Marshall SM, Mathis C, Carrick E, Keenan G, Cooper GJT, Graham H, Craven M, Gromski PS, Moore DG, Walker SI, Cronin L. Identifying molecules as biosignatures with assembly theory and mass spectrometry. Nat Commun 2021; 12:3033. [PMID: 34031398 PMCID: PMC8144626 DOI: 10.1038/s41467-021-23258-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/07/2021] [Indexed: 01/14/2023] Open
Abstract
The search for alien life is hard because we do not know what signatures are unique to life. We show why complex molecules found in high abundance are universal biosignatures and demonstrate the first intrinsic experimentally tractable measure of molecular complexity, called the molecular assembly index (MA). To do this we calculate the complexity of several million molecules and validate that their complexity can be experimentally determined by mass spectrometry. This approach allows us to identify molecular biosignatures from a set of diverse samples from around the world, outer space, and the laboratory, demonstrating it is possible to build a life detection experiment based on MA that could be deployed to extraterrestrial locations, and used as a complexity scale to quantify constraints needed to direct prebiotically plausible processes in the laboratory. Such an approach is vital for finding life elsewhere in the universe or creating de-novo life in the lab.
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Affiliation(s)
| | - Cole Mathis
- School of Chemistry, University of Glasgow, Glasgow, UK
| | - Emma Carrick
- School of Chemistry, University of Glasgow, Glasgow, UK
| | - Graham Keenan
- School of Chemistry, University of Glasgow, Glasgow, UK
| | | | - Heather Graham
- Astrobiology Analytical Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | | | - Douglas G Moore
- Beyond Centre for Concepts in Fundamental Science, Arizona State University, Tempe, AZ, USA
| | - Sara I Walker
- Beyond Centre for Concepts in Fundamental Science, Arizona State University, Tempe, AZ, USA
| | - Leroy Cronin
- School of Chemistry, University of Glasgow, Glasgow, UK.
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Mathis C, Hamitouche S, Barberot JP, Lindas P. Refractory lymphorrhoea of the neck treated with etilefrine. Eur Ann Otorhinolaryngol Head Neck Dis 2021; 138:383-386. [PMID: 33608232 DOI: 10.1016/j.anorl.2021.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND Intraoperative injury of the thoracic duct is an uncommon complication of head and neck surgery, which is difficult to manage and associated with serious consequences. We report a case of lymphorrhoea of the neck refractory to all the usual treatments that resolved in response to a treatment strategy described in thoracic and visceral surgery: use of a sympathomimetic drug, etilefrine. To our knowledge and after review of the literature, this is the first reported case of lymphorrhoea of the neck treated by etilefrine. CASE REPORT Our patient presented massive lymphatic fluid leakage following left neck dissection as part of the management of oropharyngeal cancer with lymph node metastases. The treatments usually proposed, such as intraoperative repair and appropriate dietary and drug management, were not effective, resulting in multiple, severe complications. After evaluation of the benefit-risk balance, treatment with etilefrine was introduced at the dosages proposed in the literature for the management of chylothorax. This treatment allowed complete resolution of the lymphatic fluid leak after one week. DISCUSSION Etilefrine can therefore be added to the treatment options for the management of lymphatic fluid leaks refractory to the usual treatments.
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Affiliation(s)
- C Mathis
- Service d'ORL, CHU, 29, avenue du Maréchal de Lattre de Tassigny, 54035 Nancy, France.
| | - S Hamitouche
- Service d'ORL, CHU, 29, avenue du Maréchal de Lattre de Tassigny, 54035 Nancy, France
| | - J-P Barberot
- Service d'ORL, Hôpital Robert Schuman, 57045 Metz cedex 01, France
| | - P Lindas
- Service d'ORL, Hôpital Robert Schuman, 57045 Metz cedex 01, France
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Nickols N, Kishan A, Kane N, Diaz-Perez S, Ganapathy E, Nazarian R, Felix C, Mathis C, Kwak J, Basehart V, Zomorodian N, King C, Kupelian P, Rettig M, Steinberg M, Cao M, Knudsen B, Schaue D, Reiter R. Phase I Trial of Stereotactic Body Radiotherapy Neoadjuvant to Radical Prostatectomy for Patients with Unfavorable and High-Risk Non-Metastatic Prostate Cancer: Feasibility And Safety. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.1849] [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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Abstract
We study the effects of individual perceptions of payoffs in two-player games. In particular we consider the setting in which individuals' perceptions of the game are influenced by their previous experiences and outcomes. Accordingly, we introduce a framework based on evolutionary games where individuals have the capacity to perceive their interactions in different ways. Starting from the narrative of social behaviors in a pub as an illustration, we first study the combination of the Prisoner's Dilemma and Harmony Game as two alternative perceptions of the same situation. Considering a selection of game pairs, our results show that the interplay between perception dynamics and game payoffs gives rise to nonlinear phenomena unexpected in each of the games separately, such as catastrophic phase transitions in the cooperation basin of attraction, Hopf bifurcations and cycles of cooperation and defection. Combining analytical techniques with multiagent simulations, we also show how introducing individual perceptions can cause nontrivial dynamical behaviors to emerge, which cannot be obtained by analyzing the system at a macroscopic level. Specifically, initial perception heterogeneities at the microscopic level can yield a polarization effect that is unpredictable at the macroscopic level. This framework opens the door to the exploration of new ways of understanding the link between the emergence of cooperation and individual preferences and perceptions, with potential applications beyond social interactions.
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Affiliation(s)
- Alberto Antonioni
- Grupo Interdisciplinar de Sistemas Complejos (GISC), Departamento de Matemáticas, Universidad Carlos III de Madrid, E-28911 Leganés, Madrid, Spain
| | - Luis A Martinez-Vaquero
- Institute of Cognitive Sciences and Technologies, National Research Council of Italy (ISTC-CNR), 00185 Rome, Italy
| | - Cole Mathis
- Beyond Center for Fundamental Questions in Science, Arizona State University, Tempe Arizona, USA
- Department of Physics, Arizona State University, Tempe Arizona, USA
| | - Leto Peel
- ICTEAM, Université catholique de Louvain, Avenue George Lemaître 4, B-1348 Louvain-la-Neuve, Belgium
| | - Massimo Stella
- Institute for Complex Systems Simulation, University of Southampton, 4 University Road, Southampton SO17 1BJ, United Kingdom
- Complex Science Consulting, Via Amilcare Foscarini 2, 73100, Lecce, Italy
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Abstract
The application of network science to biology has advanced our understanding of the metabolism of individual organisms and the organization of ecosystems but has scarcely been applied to life at a planetary scale. To characterize planetary-scale biochemistry, we constructed biochemical networks using a global database of 28,146 annotated genomes and metagenomes and 8658 cataloged biochemical reactions. We uncover scaling laws governing biochemical diversity and network structure shared across levels of organization from individuals to ecosystems, to the biosphere as a whole. Comparing real biochemical reaction networks to random reaction networks reveals that the observed biological scaling is not a product of chemistry alone but instead emerges due to the particular structure of selected reactions commonly participating in living processes. We show that the topology of biochemical networks for the three domains of life is quantitatively distinguishable, with >80% accuracy in predicting evolutionary domain based on biochemical network size and average topology. Together, our results point to a deeper level of organization in biochemical networks than what has been understood so far.
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Affiliation(s)
- Hyunju Kim
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Harrison B. Smith
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Cole Mathis
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- Department of Physics, Arizona State University, Tempe, AZ, USA
| | - Jason Raymond
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - Sara I. Walker
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ, USA
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
- ASU-SFI Center for Biosocial Complex Systems, Tempe, AZ, USA
- Blue Marble Space Institute of Science, Seattle, WA, USA
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11
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Wilckens KA, Tudorascu D, Snitz BE, Price J, Aizenstein H, Lopez O, Erickson K, Lopresti B, Laymon C, Minhas D, Mathis C, Buysse D, Klunk W, Cohen AD. 1008 Sleep Efficiency Moderates The Relationship Between Beta-Amyloid And Memory Retention. Sleep 2018. [DOI: 10.1093/sleep/zsy061.1007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | | | - B E Snitz
- University of Pittsburgh, Pittsburgh, PA
| | - J Price
- University of Pittsburgh, Charlestown, MA
| | | | - O Lopez
- University of Pittsburgh, Pittsburgh, PA
| | - K Erickson
- University of Pittsburgh, Pittsburgh, PA
| | - B Lopresti
- University of Pittsburgh, Pittsburgh, PA
| | - C Laymon
- University of Pittsburgh, Pittsburgh, PA
| | - D Minhas
- University of Pittsburgh, Pittsburgh, PA
| | - C Mathis
- University of Pittsburgh, Pittsburgh, PA
| | - D Buysse
- University of Pittsburgh, Pittsburgh, PA
| | - W Klunk
- University of Pittsburgh, Pittsburgh, PA
| | - A D Cohen
- University of Pittsburgh, Pittsburgh, PA
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Mathis C, Ramprasad SN, Walker SI, Lehman N. Prebiotic RNA Network Formation: A Taxonomy of Molecular Cooperation. Life (Basel) 2017; 7:life7040038. [PMID: 29035326 PMCID: PMC5745551 DOI: 10.3390/life7040038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/06/2017] [Accepted: 10/11/2017] [Indexed: 12/31/2022] Open
Abstract
Cooperation is essential for evolution of biological complexity. Recent work has shown game theoretic arguments, commonly used to model biological cooperation, can also illuminate the dynamics of chemical systems. Here we investigate the types of cooperation possible in a real RNA system based on the Azoarcus ribozyme, by constructing a taxonomy of possible cooperative groups. We construct a computational model of this system to investigate the features of the real system promoting cooperation. We find triplet interactions among genotypes are intrinsically biased towards cooperation due to the particular distribution of catalytic rate constants measured empirically in the real system. For other distributions cooperation is less favored. We discuss implications for understanding cooperation as a driver of complexification in the origin of life.
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Affiliation(s)
- Cole Mathis
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ 85287, USA.
| | - Sanjay N Ramprasad
- Department of Chemistry, Portland State University, P.O. Box 751, Portland, OR 97202, USA.
| | - Sara Imari Walker
- Beyond Center for Fundamental Concepts in Science, Arizona State University, Tempe, AZ 85287, USA.
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA.
| | - Niles Lehman
- Department of Chemistry, Portland State University, P.O. Box 751, Portland, OR 97202, USA.
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Iskandar AR, Titz B, Sewer A, Leroy P, Schneider T, Zanetti F, Mathis C, Elamin A, Frentzel S, Schlage WK, Martin F, Ivanov NV, Peitsch MC, Hoeng J. Systems toxicology meta-analysis of in vitro assessment studies: biological impact of a candidate modified-risk tobacco product aerosol compared with cigarette smoke on human organotypic cultures of the aerodigestive tract. Toxicol Res (Camb) 2017; 6:631-653. [PMID: 30090531 PMCID: PMC6062142 DOI: 10.1039/c7tx00047b] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/26/2017] [Indexed: 12/22/2022] Open
Abstract
Systems biology combines comprehensive molecular analyses with quantitative modeling to understand the characteristics of a biological system as a whole. Leveraging a similar approach, systems toxicology aims to decipher complex biological responses following exposures. This work reports a systems toxicology meta-analysis in the context of in vitro assessment of a candidate modified-risk tobacco product (MRTP) using three human organotypic cultures of the aerodigestive tract (buccal, bronchial, and nasal epithelia). Complementing a series of functional measures, a causal network enrichment analysis of transcriptomic data was used to compare quantitatively the biological impact of aerosol from the Tobacco Heating System (THS) 2.2, a candidate MRTP, with 3R4F cigarette smoke (CS) at similar nicotine concentrations. Lower toxicity was observed in all cultures following exposure to THS2.2 aerosol compared with 3R4F CS. Because of their morphological differences, a smaller exposure impact was observed in the buccal (stratified epithelium) compared with the bronchial and nasal (pseudostratified epithelium). However, the causal network enrichment approach supported a similar mechanistic impact of CS across the three cultures, including the impact on xenobiotic, oxidative stress, and inflammatory responses. At comparable nicotine concentrations, THS2.2 aerosol elicited reduced and more transient effects on these processes. To demonstrate the benefits of additional data modalities, we employed a newly established targeted mass-spectrometry marker panel to further confirm the reduced cellular stress responses elicited by THS2.2 aerosol compared with 3R4F CS in the nasal culture. Overall, this work demonstrates the applicability and robustness of the systems toxicology approach for in vitro inhalation toxicity assessment.
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Affiliation(s)
- A R Iskandar
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - B Titz
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - A Sewer
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - P Leroy
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - T Schneider
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - F Zanetti
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - C Mathis
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - A Elamin
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - S Frentzel
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - W K Schlage
- Biology consultant , Max-Baermann-Str. 21 , 51429 Bergisch Gladbach , Germany
| | - F Martin
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - N V Ivanov
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - M C Peitsch
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
| | - J Hoeng
- PMI R&D , Philip Morris Products S.A. (part of the Philip Morris International group of companies) , Quai Jeanrenaud 5 , CH-2000 Neuchâtel , Switzerland . ; ; Tel: +41 (58)242 2214
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Kumar T, Mathis C, Sathanandam S, Zurakowski D, Subramanian S, Allen J, Solimine M, Berrios L, Jackson S, Landers M, Sullivan R, Barnett S, Loftis C, Price L, Tansey J, Hoskoppal D, Knott-Craig C. Effect of Thyroid Hormone on Cardiac Function Following Orthotopic Heart Transplantation in Piglets. J Heart Lung Transplant 2017. [DOI: 10.1016/j.healun.2017.01.724] [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: 11/16/2022] Open
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Abstract
It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase is distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly. Key Words: Origin of life-Prebiotic evolution-Astrobiology-Biopolymers-Life. Astrobiology 17, 266-276.
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Affiliation(s)
- Cole Mathis
- 1 Department of Physics, Arizona State University , Tempe, Arizona
| | - Tanmoy Bhattacharya
- 2 Santa Fe Institute , Santa Fe, New Mexico
- 3 Los Alamos National Laboratory , Los Alamos, New Mexico
| | - Sara Imari Walker
- 4 Beyond Center for Fundamental Concepts in Science and School of Earth and Space Exploration, Arizona State University , Tempe, Arizona
- 5 Blue Marble Space Institute of Science , Seattle, Washington
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16
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Zanetti F, Schlage W, Sewer A, Leroy P, Majeed S, Guedj E, Trivedi K, Elamin A, Frentzel S, Iskandar A, Kostadinova R, Mathis C, Ivanov N, Peitsch M, Hoeng J. Systems toxicology assessment of a heat-not-burn product aerosol compared with cigarette smoke on organotypic buccal epithelial cultures. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.07.203] [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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17
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Frentzel S, Steiner S, Majeed S, Vuillaume G, Kleinhans S, Nordlund M, Mathis C, Hoeng J. A new fluorescence based method for the characterization of in vitro aerosol exposure systems. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.07.201] [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: 10/20/2022]
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Iskandar A, Mathis C, Martin F, Leroy P, Sewer A, Majeed S, Kuehn D, Trivedi K, Grandolfo D, Cabanski M, Guedj E, Merg C, Frentzel S, Ivanov N, Peitsch M, Hoeng J. An application of 3-D nasal cultures: Systems toxicological assessment of a candidate modified-risk tobacco product. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.07.202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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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Martinez Y, Mathis C, Xiang Y, Leroy P, Sewer A, Mejeed S, Trivedi K, Guedj E, Merg C, Iskandar A, Schlage W, Frentzel S, Ivanov N, Peitsch M, Hoeng J. Systems toxicology assessment of a heat-not-burn product aerosol compared with conventional cigarette smoke on organotypic bronchial epithelial cultures. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.07.204] [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: 11/26/2022]
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Leroy P, Mathis C, Iskandar A, Frentzel S, Elamin A, Keyur T, Garcia E, Knorr A, Ivanov N, Hoeng J, Peitsch M. Comparative systems toxicology assessment of the Tobacco Heating System 2.2 and reference cigarettes (3R4F), on human organotypic respiratory tissue cultures. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.06.1588] [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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21
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Kogel U, Gonzalez Suarez I, Xiang Y, Dossin E, Guy PA, Mathis C, Marescotti D, Goedertier D, Martin F, Peitsch MC, Hoeng J. Biological impact of cigarette smoke compared to an aerosol produced from a prototypic modified risk tobacco product on normal human bronchial epithelial cells. Toxicol In Vitro 2015; 29:2102-15. [PMID: 26277032 DOI: 10.1016/j.tiv.2015.08.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/10/2015] [Accepted: 08/10/2015] [Indexed: 01/09/2023]
Abstract
Cigarette smoking causes serious and fatal diseases. The best way for smokers to avoid health risks is to quit smoking. Using modified risk tobacco products (MRTPs) may be an alternative to reduce the harm caused for those who are unwilling to quit smoking, but little is known about the toxic effects of MRTPs, nor were the molecular mechanisms of toxicity investigated in detail. The toxicity of an MRTP and the potential molecular mechanisms involved were investigated in high-content screening tests and whole genome transcriptomics analyses using human bronchial epithelial cells. The prototypic (p)MRTP that was tested had less impact than reference cigarette 3R4F on the cellular oxidative stress response and cell death pathways. Higher pMRTP aerosol extract concentrations had impact on pathways associated with the detoxification of xenobiotics and the reduction of oxidative damage. A pMRTP aerosol concentration up to 18 times higher than the 3R4F caused similar perturbation effects in biological networks and led to the perturbation of networks related to cell stress, and proliferation biology. These results may further facilitate the development of a systems toxicology-based impact assessment for use in future risk assessments in line with the 21st century toxicology paradigm, as shown here for an MRTP.
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Affiliation(s)
- U Kogel
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - I Gonzalez Suarez
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - Y Xiang
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - E Dossin
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - P A Guy
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - C Mathis
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - D Marescotti
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - D Goedertier
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - F Martin
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - M C Peitsch
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
| | - J Hoeng
- Philip Morris International R&D, Philip Morris Products S.A., Quai Jeanrenaud 5, 2000 Neuchâtel, Switzerland.
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Steiner S, Majeed S, Pierrick D, Vuillaume G, Dossin E, Guy P, Frentzel S, Nordlund M, Mathis C, Bentley M, Hoeng J. Gas-vapor phase and particulate matter partitioning of 3R4F aerosol components and their delivery in the Vitrocell 24/48 ® aerosol exposure system. Toxicol Lett 2015. [DOI: 10.1016/j.toxlet.2015.08.400] [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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Mathis C, Iskandar A, Johne S, Majeed S, Grandolfo D, Kuehn D, Merg C, Elamin A, Guedj E, Dulize R, Peric D, Trivedi K, Benyagoub A, Xiang Y, Martin F, Leroy P, Frentzel S, Ivanov N, Peitsch M, Hoeng J. Assessment of the Tobacco Heating System 2.2, a candidate Modified Risk Tobacco Product, on human organotypic nasal and bronchial epithelial tissue culture using systems toxicology approach. Toxicol Lett 2015. [DOI: 10.1016/j.toxlet.2015.08.920] [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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Roucher A, Zaoui P, Tartry D, Choukroun G, Mathis C, Moulin B, Fauvel J. Surveillance de la kaliémie et de la créatininémie au cours des essais cliniques par le laboratoire centralisé ou local ? Nephrol Ther 2015. [DOI: 10.1016/j.nephro.2015.07.393] [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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Schaefer E, Lauer J, Durand M, Pelletier V, Obringer C, Claussmann A, Braun JJ, Redin C, Mathis C, Muller J, Schmidt-Mutter C, Flori E, Marion V, Stoetzel C, Dollfus H. Mesoaxial polydactyly is a major feature in Bardet-Biedl syndrome patients with LZTFL1 (BBS17) mutations. Clin Genet 2013; 85:476-81. [PMID: 23692385 DOI: 10.1111/cge.12198] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [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: 02/06/2013] [Revised: 05/16/2013] [Accepted: 05/16/2013] [Indexed: 10/26/2022]
Abstract
Ciliopathies are heterogeneous disorders sharing different clinical signs due to a defect at the level of the primary cilia/centrosome complex. Postaxial polydactyly is frequently reported in ciliopathies, especially in Bardet-Biedl syndrome (BBS). Clinical features and genetic results observed in a pair of dizygotic twins with BBS are reported. The following manifestations were present: retinitis pigmentosa, bilateral insertional polydactyly, cognitive impairment and renal dysfunction. X-rays of the hands confirmed the presence of a 4th mesoaxial extra-digit with Y-shaped metacarpal bones. The sequencing of LZTFL1 identified a missense mutation (NM_020347.2: p.Leu87Pro; c.260T>C) and a nonsense mutation (p.Glu260*; c.778G>T), establishing a compound heterozygous status for the twins. A major decrease of LZTFL1 transcript and protein was observed in the patient's fibroblasts. This is the second report of LZTFL1 mutations in BBS patients confirming LZTFL1 as a BBS gene. Interestingly, the only two families reported in literature thus far with LZTFL1 mutations have in common mesoaxial polydactyly, a very uncommon feature for BBS. This special subtype of polydactyly in BBS patients is easily identified on clinical examination and prompts for priority sequencing of LZTFL1 (BBS17).
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Affiliation(s)
- E Schaefer
- Laboratoire de Génétique Médicale, INSERM U1112, Faculté de Médecine de Strasbourg, Universitaires de Strasbourg, Strasbourg, France
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Dodart JC, Mathis C, Ungerer A. Des formes sécrétées du précurseur de la protéine ß-amyloïde impliqué dans la maladie d'Alzheimer améliorent la mémoire des souris. Med Sci (Paris) 2012. [DOI: 10.4267/10608/1319] [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: 11/30/2022] Open
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27
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Ikonomovic M, Price J, Abrahamson E, Mathis C, Paljug W, Debnath M, Shao L, Becker C, Hamilton R, Klunk W. Direct Correlations of [H-3]Flutemetamol Binding with [H-3]PiB Binding and Amyloid-beta Concentration and Plaque Load in [C-11]PiB Imaged Brains (S34.002). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.s34.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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28
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Prieux-Lucas K, Touati S, Lemdani M, Perron S, Serapicos D, Mathis C, Laporte C, Perna S, Plouvier E, Thuillier F, Forceville X. P118 La supplémentation protéique et calorique du petit déjeuner améliore-t-elle l’état nutritionnel des patients hospitalisés ? NUTR CLIN METAB 2011. [DOI: 10.1016/s0985-0562(11)70185-6] [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: 11/26/2022]
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29
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Jannes G, Piquet R, Maïssa P, Mathis C, Rousseaux G. Experimental demonstration of the supersonic-subsonic bifurcation in the circular jump: a hydrodynamic white hole. Phys Rev E Stat Nonlin Soft Matter Phys 2011; 83:056312. [PMID: 21728652 DOI: 10.1103/physreve.83.056312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 02/17/2011] [Indexed: 05/31/2023]
Abstract
We provide an experimental demonstration that the circular hydraulic jump represents a hydrodynamic white hole or gravitational fountain (the time reverse of a black hole) by measuring the angle of the Mach cone created by an object in the "supersonic" inner flow region. We emphasize the general character of this gravitational analogy by showing theoretically that the white hole horizon constitutes a stationary and spatial saddle-node bifurcation within dynamical-systems theory. We also demonstrate that the inner region has a "superluminal" dispersion relation, that is, that the group velocity of the surface waves increases with frequency, and discuss some possible consequences with respect to the robustness of Hawking radiation. Finally, we point out that our experiment shows a concrete example of a possible "trans-Planckian distortion" of black or white holes.
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Affiliation(s)
- G Jannes
- Université de Nice Sophia Antipolis, Laboratoire J.-A. Dieudonné, UMR CNRS-UNS 6621, Parc Valrose, F-06108 Nice Cedex 02, France
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Abstract
G protein-coupled receptor (GPCR) associated sorting protein-1 (GASP-1) is suspected to play a key role in recycling and degradation of several GPCRs. In a previous study, we have shown that GASP-1-knock-out (GASP-1-KO) mice displayed deficits in acquiring a cocaine self-administration task, associated with an exacerbated down-regulation of striatal dopaminergic and cholinergic receptors. Among several possibilities, GASP-1 deficiency could have impaired memory processes underlying the acquisition of the operant conditioning task. Therefore, the present study investigated cognitive performances of GASP-1-KO mice and their wild-type littermates (WT) in a broad variety of memory tasks. Consistent with a deficit in procedural memory, GASP-1-KO mice showed delayed acquisition of a food-reinforced bar-press task. During water-maze training in hidden- or visible-platform paradigms, mutant and WT mice acquired the tasks at the same rate. However, GASP-1 mice exhibited persistent thigmotaxic swimming, longer distance to the platform, and reduced swim speed. There was no deficit in several tasks requiring simple behavioral responses (Barnes maze, object recognition and passive avoidance tasks). Thus, the ability to acquire and/or express complex responses seems affected in GASP-1-deficient mice. Hippocampal functions were preserved, as the retention of an acquired memory in spatial tasks remained unaffected. The pattern of behavioral deficits observed in GASP-1-KO mice is coherent with current knowledge on the role of striatal GPCRs in acquisition/expression of skilled behavior and in motivation. Together with the previous findings, the so far established phenotype of GASP-1-KO mice makes them a potentially exciting tool to study striatal functions.
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Affiliation(s)
- C Mathis
- Laboratoire d'Imagerie et de Neurosciences Cognitives, FRE 3289 Université de Strasbourg-CNRS, IFR 37 de Neurosciences, GDR 2905 CNRS, 12 rue Goethe, Strasbourg, France.
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Yoshikawa HN, Mathis C, Maïssa P, Rousseaux G, Douady S. Pattern formation in bubbles emerging periodically from a liquid free surface. Eur Phys J E Soft Matter 2010; 33:11-18. [PMID: 20848154 DOI: 10.1140/epje/i2010-10645-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Accepted: 07/21/2010] [Indexed: 05/29/2023]
Abstract
Patterns formed by centimeter scale bubbles on the free surface of a viscous liquid are investigated in a cylindrical container. These bubbles emerge periodically at the surface and interact with each other in the central zone. Their radial emission, due to interaction and radial surface flow, leads to the formation of a variety of patterns. Different star-like and spiral patterns appear spontaneously by increasing the bubble emergence frequency. It is found that these patterns are due to a constant angular shift in the bubble emission direction. Measurements of this angular shift show a supercritical bifurcation accompanied by a transition from a pattern of two opposed straight arms to spiral patterns. By applying the tools and concepts from the study of leaf arrangement in botany (phyllotaxis), the recognized patterns and the mechanism of the pattern formation are discussed. Close similarities to the leaf arrangement are found in the behavior of the angular shift and the patterns. These findings suggest that the observed patterns are formed by a packing mechanism of successively appearing elements (bubbles), which is similar to that of the leaves at the earliest stage of phyllotaxis.
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Affiliation(s)
- H N Yoshikawa
- Laboratoire J.-A. Dieudonné, UMR 6621 CNRS/Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 02, France.
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Pozdnyakov O, Pozdnyakov A, Schmaltz B, Mathis C. Thermal degradation in bulk and thin films of 2-, 4-, and 6-arm polystyrene stars with a C60 core. POLYMER 2006. [DOI: 10.1016/j.polymer.2005.12.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Crowell MD, Mathis C, Schettler VA, Yunus T, Lacy BE. The effects of tegaserod, a 5-HT receptor agonist, on gastric emptying in a murine model of diabetes mellitus. Neurogastroenterol Motil 2005; 17:738-43. [PMID: 16185313 DOI: 10.1111/j.1365-2982.2005.00681.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
UNLABELLED The C57BLKS/J db/db transgenic mouse is a model of diabetes mellitus that has been shown to have delayed gastric emptying. We assessed gastric emptying rates in C57BLKS/J mice, and determined the effects of tegaserod, a new selective 5-HT(4) receptor partial agonist, on gastric emptying. METHODS Gastric emptying rates of a 20% glucose test meal were determined in 12-20-week-old female db/db mice and control littermates. The effects of tegaserod (0.1-2.0 mg kg(-1), i.p.) on gastric transit were tested in a second group of db/db mice. Pretreatment with GR11308, a specific 5-HT(4)antagonist, was used to confirm the mechanism of action of tegaserod on gastric emptying. RESULTS Gastric emptying of glucose was significantly slower in db/db mice than in control littermates. Tegaserod (0.1 mg kg(-1)) significantly accelerated the gastric emptying rate of glucose in db/db mice, reducing the fraction of the meal remaining in the stomach at 30 min by 80%. GR11308 blocked the gastrokinetic effects of tegaserod. CONCLUSIONS Gastric emptying was impaired in db/db mice. Low dose tegaserod improved gastric emptying rates in this model of gastroparesis through the activation of 5-HT(4) receptors. These findings suggest that 5-HT(4) receptor agonists may prove useful for improving delayed gastric emptying in gastroparesis.
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Affiliation(s)
- M D Crowell
- The Marvin M. Schuster Center for Digestive and Motility Disorders, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Pirat C, Mathis C, Maïssa P, Gil L. Structures of a continuously fed two-dimensional viscous film under a destabilizing gravitational force. Phys Rev Lett 2004; 92:104501. [PMID: 15089210 DOI: 10.1103/physrevlett.92.104501] [Citation(s) in RCA: 3] [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] [Received: 06/27/2003] [Indexed: 05/24/2023]
Abstract
We study the gravity induced instability of a liquid film formed below a plane grid which is used as a porous media in an original hydrodynamic experiment. The film is continuously supplied with a controlled flow rate. We give through a phase diagram the full spectrum of the different flow regimes and we investigate the dynamics of the observed structures. True secondary instabilities of a 2D periodic pattern are described. The control parameters are the flow rate and the viscosity.
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Affiliation(s)
- C Pirat
- Institut du Non Linéaire de Nice (UMR CNRS 6618), Université de Nice Sophia Antipolis, 1361 Route des Lucioles, F-06560 Valbonne, France.
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Bullinger M, Morfeld M, Kohlmann T, Nantke J, van den Bussche H, Dodt B, Dunkelberg S, Kirchberger I, Krüger-Bödecker A, Lachmann A, Lang K, Mathis C, Mittag O, Peters A, Raspe HH, Schulz H. [SF-36 Health Survey in Rehabilitation Research. Findings from the North German Network for Rehabilitation Research, NVRF, within the rehabilitation research funding program]. Rehabilitation (Stuttg) 2003; 42:218-25. [PMID: 12938044 DOI: 10.1055/s-2003-41645] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The SF-36 Health Survey and its 12-item abridged form is an instrument for the assessment of health related quality of life that can be used with healthy persons and patient populations. Its use has been recommended within a large German multicentre rehabilitation research programme. The paper examines missing data across all five study projects of the North German Network for Rehabilitation Research (NVRF) as well as psychometric properties of the instrument. In addition, data were compared to representative norm data using the SF-36 (SF-12) in the German National Health Survey. Results showed that there were few missing data in the SF-36. Examining the impact of age, gender and health status yielded effects of higher age and female gender on missing data. Psychometric analyses showed good to excellent results of the instrument in terms of scale fit and reliability. In terms of convergent validity, medium to high correlation of the SF-36 subscales with comparable instruments (e. g. SCL-90-R) could be found. Summarizing, the SF-36/SF-12 can be recommended for use in rehabilitation research. Analyses regarding sensitivity should be conducted in future studies.
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Affiliation(s)
- M Bullinger
- Arbeitsgruppe Lebensqualitätsforschung bei Erwachsenen und Kindern, Institut und Poliklinik für Medizinische Psychologie, Zentrum für Psychosoziale Medizin, Universitätsklinikum Hamburg-Eppendorf.
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Abstract
Small animal models that manifest many of the characteristic neuropathological and behavioral features of Alzheimer's disease (AD) have been developed and have proven of great value for studying the pathogenesis of this disorder at the molecular, cellular and behavioral levels. The great progress made in our understanding of the genetic factors that either cause or contribute to the risk of developing AD has prompted many laboratories to create transgenic (tg) mice that overexpress specific genes which cause familial forms of the disease. Several of these tg mice display neuropathological and behavioral features of AD including amyloid beta-peptide (A beta) and amyloid deposits, neuritic plaques, gliosis, synaptic alterations and signs of neurodegeneration as well as memory impairment. Despite these similarities, important differences in neuropathology and behavior between these tg mouse models and AD have also been observed, and to date no perfect animal model has emerged. Moreover, ascertaining which elements of the neuropathological and behavioral phenotype of these various strains of tg mice are relevant to that observed in AD continues to be a challenge. Here we provide a critical review of the AD-like neuropathology and behavioral phenotypes of several well-known and utilized tg mice that express human APP transgenes.
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Affiliation(s)
- J C Dodart
- Neuroscience Discovery Research, Eli Lilly and Company, Indianapolis, IN 46285, USA.
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Schikowski A, Thewissen M, Mathis C, Ross HG, Enck P. Serotonin type-4 receptors modulate the sensitivity of intramural mechanoreceptive afferents of the cat rectum. Neurogastroenterol Motil 2002; 14:221-7. [PMID: 12061906 DOI: 10.1046/j.1365-2982.2002.00328.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
It has been suggested that serotonin (5-hydroxytryptamine) type-4 (5-HT4) receptors modulate the sensitivity of intrinsic afferents of the intestinal mucosa. We studied the involvement of 5-HT4receptors in the modulation of extrinsic afferent sensitivity of the intestinal wall. During distension ramps, mechanoreceptive rectal afferents in sacral dorsal roots were examined in decerebrate anaesthesia-free cats using the selective 5-HT4receptor partial agonist, tegaserod (HTF 919), and the 5-HT4receptor antagonist, SB 203186. The static discharge rate of the afferents evoked by rectal distension decreased after intravenous (i.v.) administration of tegaserod at intraluminal pressures above 30 mmHg, with the most effective reduction occurring at 50 mmHg. The effect was dose-dependent, with maximal reduction occurring at 1.2 mg kg-1 bodyweight, and could be partly reversed by i.v. administration of SB 203186. Tegaserod did not alter the pressure-volume relationship (compliance) of the rectum. It is tentatively concluded that 5-HT4receptor activation has an inhibitory effect on intramural mechanoreceptors in the cat's rectum. Our results are in line with the observation that tegaserod relieves the sensory symptoms of patients suffering from irritable bowel syndrome.
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Affiliation(s)
- A Schikowski
- Physiologisches Institut, Heinrich-Heine-Universität, Düsseldorf, Germany
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Venturini J, Koudoumas E, Couris S, Janot JM, Seta P, Mathis C, Leach S. Optical limiting and nonlinear optical absorption properties of C60–polystyrene star polymer films: C60 concentration dependence. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b201308h] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Mathis C, Hogen-Esch TE. Oligomerization of Vinyl Monomers. 2. Evidence for a conformationally restrained six-membered ring containing lithium ion. J Am Chem Soc 2002. [DOI: 10.1021/ja00366a053] [Citation(s) in RCA: 17] [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: 11/28/2022]
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Mathis C, Denisenko-Nehrbass N, Girault JA, Borrelli E. Essential role of oligodendrocytes in the formation and maintenance of central nervous system nodal regions. Development 2001; 128:4881-90. [PMID: 11731467 DOI: 10.1242/dev.128.23.4881] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [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: 11/20/2022]
Abstract
The membrane of myelinated axons is divided into functionally distinct domains characterized by the enrichment of specific proteins. The mechanisms responsible for this organization have not been fully identified. To further address the role of oligodendrocytes in the functional segmentation of the axolemma in vivo, the distribution of nodal (Na+ channels, ankyrin G), paranodal (paranodin/contactin-associated-protein) and juxtaparanodal (Kv1.1 K+ channels) axonal markers, was studied in the brain of MBP-TK and jimpy mice. In MBP-TK transgenic mice, oligodendrocyte ablation was selectively induced by FIAU treatment before and during the onset of myelination. In jimpy mice, oligodendrocytes degenerate spontaneously within the first postnatal weeks after the onset of myelination. Interestingly, in MBP-TK mice treated for 1-20 days with FIAU, despite the ablation of more than 95% of oligodendrocytes, the protein levels of all tested nodal markers was unaltered. Nevertheless, these proteins failed to cluster in the nodal regions. By contrast, in jimpy mice, despite a diffused localization of paranodin, the formation of nodal clusters of Na+ channels and ankyrin G was observed. Furthermore, K+ channels clusters were transiently visible, but were in direct contact with nodal markers. These results demonstrate that the organization of functional domains in myelinated axons is oligodendrocyte dependent. They also show that the presence of these cells is a requirement for the maintenance of nodal and paranodal regions.
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Affiliation(s)
- C Mathis
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM/CNRS/ULP, BP 163, 67404 Illkirch Cedex, C.U. de Strasbourg, France
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Koudoumas E, Konstantaki M, Mavromanolakis A, Couris S, Ederle Y, Mathis C, Seta P, Leach S. Ultrafast nonlinear optical response of C60–polystyrene star polymers. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)00088-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mathis C, Hindelang C, LeMeur M, Borrelli E. A transgenic mouse model for inducible and reversible dysmyelination. J Neurosci 2000; 20:7698-705. [PMID: 11027231 PMCID: PMC6772884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Oligodendrocytes are glial cells devoted to the production of myelin sheaths. Myelination of the CNS occurs essentially after birth. To delineate both the times of oligodendrocyte proliferation and myelination, as well as to study the consequence of dysmyelination in vivo, a model of inducible dysmyelination was developed. To achieve oligodendrocyte ablation, transgenic animals were generated that express the herpes virus 1 thymidine kinase (HSV1-TK) gene under the control of the myelin basic protein (MBP) gene promoter. The expression of the MBP-TK transgene in oligodendrocytes is not toxic on its own; however, toxicity can be selectively induced by the systemic injection of animals with nucleoside analogs, such as FIAU [1-(2-deoxy-2-fluoro-beta-delta-arabinofuranosyl)-5-iodouracil]. This system allows us to control the precise duration of the toxic insult and the degree of ablation of oligodendrocytes in vivo. We show that chronic treatment of MBP-TK mice with FIAU during the first 3 postnatal weeks triggers almost a total depletion of oligodendrocytes in the CNS. These effects are accompanied by a behavioral phenotype characterized by tremors, seizures, retarded growth, and premature animal death. We identify the period of highest oligodendrocytes division in the first 9 postnatal days. Delaying the beginning of FIAU treatments results in different degrees of dysmyelination. Dysmyelination in MBP-TK mice is always accompanied by astrocytosis. Thus, this transgenic line provides a model to study the events occurring during dysmyelination of various intensities. It also represents an invaluable tool to investigate remyelination in vivo.
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Affiliation(s)
- C Mathis
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, National de la Recherche Scientifique/Université Louis Pasteur, 67404 Illkirch Cedex, France
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Abstract
Regional 5-hydroxytryptamine(1A) (5-HT(1A)) receptor binding potential (BP) of depressed subjects with primary, recurrent, familial mood disorders was compared to that of healthy controls by using positron emission tomography and [carbonyl-(11)C]WAY-100635 ¿[(11)C]N-(2-(4-(2-methoxyphenyl)-1-piperazin-1-yl)ethyl)-N-(2- pyridy l)cyclohexanecarboxamide¿. The mean 5-HT(1A) receptor BP was reduced 42% in the midbrain raphe and 25-33% in limbic and neocortical areas in the mesiotemporal, occipital, and parietal cortex. The magnitude of these abnormalities was most prominent in bipolar depressives and unipolar depressives who had bipolar relatives. These abnormal reductions in 5-HT(1A) receptor BP are consistent with in vivo evidence that 5-HT(1A) receptor sensitivity is reduced in major depressive disorder and postmortem data showing a widespread deficit of 5-HT(1A) receptor expression in primary mood disorders.
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Affiliation(s)
- W C Drevets
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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Abstract
Intensive investigation towards the understanding of the biology and physiological functions of the beta-amyloid precursor protein (APP) have been supported since it is known that a 39-43 amino acid fragment of APP, called the beta-amyloid protein (Abeta), accumulates in the brain parenchyma to form the typical lesions associated with Alzheimer's disease (AD). It emerges from extensive data that APP and its derivatives show a wide range of contrasting physiological properties and therefore might be involved in distinct physiological functions. Abeta has been shown to disrupt neuronal activity and to demonstrate neurotoxic properties in a wide range of experimental procedures. In contrast, both in vitro and in vivo studies suggest that APP and/or its secreted forms are important factors involved in the viability, growth and morphological and functional plasticity of nerve cells. Furthermore, several recent studies suggest that APP and its derivatives have an important role in learning and memory processes. Memory impairments can be induced in animals by intracerebral treatment with Abeta. Altered expression of the APP gene in aged animals or in genetically-modified animals also leads to memory deficits. By contrast, secreted forms of APP have recently been shown to facilitate learning and memory processes in mice. These interesting findings open novel perspectives to understand the involvement of APP in the development of cognitive deficits associated with AD. In this review, we summarize the current data concerning the biology and the behavioral effects of APP and its derivatives which may be relevant to the roles of these proteins in memory and in AD pathology.
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Affiliation(s)
- J C Dodart
- Laboratoire d'Ethologie et Neurobiologie, URA-CNRS 1295, ULP, Strasbourg, France.
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Dodart JC, Mathis C, Saura J, Bales KR, Paul SM, Ungerer A. Neuroanatomical abnormalities in behaviorally characterized APP(V717F) transgenic mice. Neurobiol Dis 2000; 7:71-85. [PMID: 10783292 DOI: 10.1006/nbdi.1999.0278] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.9] [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: 11/22/2022] Open
Abstract
Histological analyses were performed on the brains of APP(V717F) transgenic (Tg)mice previously studied in a battery of behavioral tests. We describe here the regional and age-dependent deposition of amyloid in both heterozygous and homozygous Tg mice. We also report that Tg mice show significant and age-dependent changes in synaptic density measured by synaptophysin immunoreactivity. Surprisingly, a rather marked hippocampal atrophy is observed as early as 3 months of age in Tg mice (20-40%). Statistical analyses revealed that the deficits in object recognition memory are related to the number of amyloid deposits in specific brain regions, whereas deficits in spatial reference and working memory are related to the changes in synaptic density and hippocampal atrophy. Our study suggests that the behavioral deficits observed in Tg mice are only in part related to amyloid deposition, but are also related to neuroanatomical alterations secondary to overexpression of the APP(V717F) transgene and independent of amyloid deposition.
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Affiliation(s)
- J C Dodart
- ULP, URA-CNRS 1295, 7 Rue de l'Université, Strasbourg, France
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