101
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Mohamed ISI, Dang HD, Beltempo M, Kabbara H, Barrington KJ, Lefebvre F. Tendencies of Medical Coverage in North American Neonatal Intensive Care Units (Nicus). Paediatr Child Health 2009. [DOI: 10.1093/pch/14.suppl_a.34a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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102
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Oueslati J, Kefi R, Lefebvre F, Rzaigui M, Nasr CB. Crystal Structure and Spectroscopic Studies of a New Organic Dihydrogenmonophosphate [2-NH2-6-CH3-C4H3N2O]2(H2PO4)2. PHOSPHORUS SULFUR 2009. [DOI: 10.1080/10426500802196794] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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103
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Theret E, Lefebvre F, Noudel R, Eap C, Litre C, Rousseaux P, Scherpereel B. Énorme kyste neurentérique intramédullaire avec extension intrathoracique chez un nourrisson de 1 mois : approche antérieure chirurgicale. À propos d’un cas et revue de la littérature. Neurochirurgie 2008. [DOI: 10.1016/j.neuchi.2008.08.104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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104
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Pain F, Dhenain M, Gurden H, Routier AL, Lefebvre F, Mastrippolito R, Lanièce P. A method based on Monte Carlo simulations and voxelized anatomical atlases to evaluate and correct uncertainties on radiotracer accumulation quantitation in beta microprobe studies in the rat brain. Phys Med Biol 2008; 53:5385-404. [DOI: 10.1088/0031-9155/53/19/008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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105
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Legent G, Delaune A, Norris V, Delcorte A, Gibouin D, Lefebvre F, Misevic G, Thellier M, Ripoll C. Method for macromolecular colocalization using atomic recombination in dynamic SIMS. J Phys Chem B 2008; 112:5534-46. [PMID: 18399679 DOI: 10.1021/jp7100489] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Localizing two or more components of assemblies in biological systems requires both continued development of fluorescence techniques and invention of entirely new techniques. Candidates for the latter include dynamic secondary ion mass spectrometry (D-SIMS). The latest generation of D-SIMS, the Cameca NanoSIMS 50, permits the localization of specific, isotopically labeled molecules and macromolecules in sections of biological material with a resolution in the tens of nanometers and with a sensitivity approaching in principle that of a single protein. Here we use two different systems, crystals of glycine and mixtures of proteins, to show that the formation of recombinant CN secondary ions under Cs bombardment can be exploited to create a new colocalization technique. We show experimentally that the formation of the recombinant (13)C(15)N secondary ion between (13)C- and (15)N-labeled macromolecules is indeed an indicator of the distance between the interacting macromolecules and on their shape. We build up a convolution model of the mixing-recombination process in D-SIMS that allows quantitative interpretations of the distance-dependent formation of the recombinant CN. Our results show that macromolecules can be colocalized if they are within 2 nm of one another. We discuss the potential advantages of this new technique for biological applications.
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106
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Szabo-Fresnais N, Lefebvre F, Fischmeister R, Pomérance M. cAMP increases autocrine IL-1-induced IL-6 production in cardiomyocytes leading to hypertrophic signal transduction pathways. J Mol Cell Cardiol 2008. [DOI: 10.1016/j.yjmcc.2008.02.168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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107
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Oueslati A, Kefi R, Ben Nasr C, Lefebvre F. Crystal structure of a new organic hydrogenmonophosphate adduct [2-NH2-6-CH3-C4H3N2O]2HPO4. J Mol Struct 2007. [DOI: 10.1016/j.molstruc.2007.01.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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108
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Kefi R, Nasr CB, Lefebvre F. Synthesis and Characterization of a New Monophosphate (C6H6NCl2)(H2PO4) with an Interesting Chlorine-Mediated Framework. PHOSPHORUS SULFUR 2007. [DOI: 10.1080/10426500701370300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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109
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Bordoloi A, Lefebvre F, Halligudi S. Organotin-oxometalate coordination polymer catalyzed oxyfunctionalization of monoterpenes. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2007.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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110
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Sawant DP, Vinu A, Mirajkar S, Lefebvre F, Ariga K, Anandan S, Mori T, Nishimura C, Halligudi S. Silicotungstic acid/zirconia immobilized on SBA-15 for esterifications. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2007.02.029] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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111
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Kefi R, Lefebvre F, Ben Nasr C. Synthesis and characterization of a layered chlorozincophosphate templated by protonated 4-methylpiperidine. CRYSTAL RESEARCH AND TECHNOLOGY 2007. [DOI: 10.1002/crat.200610824] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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112
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Oueslati J, Rayes A, Nasr CB, Lefebvre F. Synthesis and Characterization of Two New Compounds: N(C2H4NH3)3(H2TO4)(HTO4)·2H2O (T = P, As). PHOSPHORUS SULFUR 2007. [DOI: 10.1080/10426500500269992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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113
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Nassar G, Sabra M, Lefebvre F, Toubal M, Nongaillard B, Noel Y. Design of low-frequency ultrasonic sensors for the analysis of the draining stage of cheese production. ULTRASONICS 2006; 44:e1045-e1050. [DOI: 10.1016/j.ultras.2006.05.100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
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114
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Kefi R, Ben Nasr C, Lefebvre F, Rzaigui M. Hydrothermal synthesis and characterization of a new zinc phosphate [Zn2.5(HPO4)2(PO4)][C6H10N2]·5H2O. Polyhedron 2006. [DOI: 10.1016/j.poly.2006.05.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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115
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Kefi R, Nasr CB, Lefebvre F, Rzaigui M. The Synthesis and Characterization of a New Layered Chlorozincophosphate Zn(HPO4)Cl[C4H10N]. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426500600614782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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116
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Oueslati A, Touati A, Nasr CB, Lefebvre F. The Synthesis and Characterization of 2-Amino-3-methylpyridinium Dihydrogenmonophosphate: (C6H9N2)H2PO4. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426500600614196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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117
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Kumbar SM, Shanbhag G, Lefebvre F, Halligudi S. Heteropoly acid supported on titania as solid acid catalyst in alkylation of p-cresol with tert-butanol. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.molcata.2006.05.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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118
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Mrad ML, Nasr CB, Rzaigui M, Lefebvre F. Synthesis, Crystal Structure, and NMR Spectroscopy of a New P-Phenylenediamonium Diphosphate [ p-NH 3C 6H 4NH 3]H 2P 2O 7. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/10426500500366558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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119
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Dérue C, Gibouin D, Lefebvre F, Studer D, Thellier M, Ripoll C. Relative Sensitivity Factors of Inorganic Cations in Frozen-hydrated Standards in Secondary Ion MS Analysis. Anal Chem 2006; 78:2471-7. [PMID: 16615752 DOI: 10.1021/ac051518u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe the measurement, at 100 K, of the SIMS relative sensitivity factors (RSFs) of the main physiological cations Na+, K+, Mg2+, and Ca2+ in frozen-hydrated (F-H) ionic solutions. Freezing was performed by either plunge freezing or high-pressure freezing. We also report the measurement of the RSFs in flax fibers, which are a model for ions in the plant cell wall, and in F-H ionic samples, which are a model for ions in the vacuole. RSFs were determined under bombardment with neutral oxygen (FAB) for both the fibers and the F-H samples. We show that referencing to ice-characteristic secondary ions is of little value in determining RSFs and that referencing to K is preferable. The RSFs of Na relative to K and of Ca relative to Mg in F-H samples are similar to their respective values in fiber samples, whereas the RSFs of both Ca and Mg relative to K are lower in fibers than in F-H samples. Our data show that the physical factors important for the determination of the RSFs are not the same in F-H samples and in homogeneous matrixes. Our data show that it is possible to perform a SIMS relative quantification of the cations in frozen-hydrated samples with an accuracy on the order of 15%. Referencing to K permits the quantification of the ionic ratios, even when the absolute concentration of the referencing ion is unknown. This is essential for physiological studies of F-H biological samples.
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120
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Mrad ML, Ben Nasr C, Rzaigui M, Lefebvre F. Synthesis and Crystal Structure of a New Adduct 4-Benzyl Piperidinium Dihydrogenphosphate Phosphoric Acid [C 12H 16NH 2] 2 (H 2PO 4) 2 H 3PO 4. PHOSPHORUS SULFUR 2006. [DOI: 10.1080/104265090968613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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121
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Poulin R, Lefebvre F. Alternative life-history and transmission strategies in a parasite: first come, first served? Parasitology 2005; 132:135-41. [PMID: 16393362 DOI: 10.1017/s003118200500870x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 07/04/2005] [Accepted: 07/04/2005] [Indexed: 11/06/2022]
Abstract
Alternative transmission strategies are common in many parasitic organisms, often representing discrete phenotypes adopted in response to external cues. The facultative truncation of the normal 3-host life-cycle to a 2-host cycle in many trematodes provides an example: some individuals mature precociously, via progenesis, in their intermediate host and produce eggs without the need to reach a definitive host. The factors that determine how many and which individuals adopt the truncated life-cycle within a parasite population remain unknown. We investigated the occurrence of progenesis in the trematode Stegodexamene anguillae within its fish intermediate host. Location within the host was a key determinant of progenesis. Although the size and egg output of progenetic metacercariae encysted in host gonads did not differ from those of the few progenetic metacercariae in other host tissues, the likelihood of metacercariae becoming progenetic was much higher for those in the gonads than those elsewhere in the host. Progenetic parasites can only evacuate their eggs along with host eggs or sperm, providing a link between the parasite's transmission strategy and its location in the host. Host size and sex, and the presence of other parasite species in the host, did not affect the occurrence of progenesis in S. anguillae. However, the proportion of metacercariae in host gonads and the proportion of progenetic metacercariae both decreased with increasing numbers of S. anguillae per host. These results suggest that progenesis is adopted mostly by the parasites that successfully establish in host gonads. These are generally the first to infect a fish; subsequent arrivals settle in other tissues as the gonads quickly become saturated with parasites. In this system, the site of encystment within the fish host both promotes and constrains the adoption of a facultative, truncated life-cycle by the parasite.
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122
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Lefebvre F, Poulin R. Progenesis in digenean trematodes: a taxonomic and synthetic overview of species reproducing in their second intermediate hosts. Parasitology 2005; 130:587-605. [PMID: 15977895 DOI: 10.1017/s0031182004007103] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Precocious egg production, i.e. progenesis, has been documented for a number of species in scattered reports throughout the trematode literature. The last 2 extensive studies on the subject date from Buttner in the early 1950s (in French) and from Tang in the early 1980s (in Chinese). Overall, 43 species were then known for their ability to produce eggs at the metacercarial stage while still in the second intermediate host. Here, we update the list, and document the existence of progenesis in a total of 79 digenean trematode species, for which we provide information on the taxonomy of the hosts, the facultative or obligate character of progenesis, relevant references, as well as some other pertinent biological information. We then review the subject by asking 7 questions of fundamental evolutionary importance. These include: What favours progenetic development? What are the associated costs and benefits? How are progenetic eggs released from the host? While exposing the various opinions of previous authors, we attempt to give a synthetic overview and stress on the importance of the metacercarial cyst wall (whether it is present, and if so its thickness) in the evolution and the adoption of a progenetic life-cycle.
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123
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Ni KF, Shan GR, Weng ZX, Sheibat-Othman N, Fevotte G, Lefebvre F, Bourgeat-Lami E. Synthesis of Hybrid Core−Shell Nanoparticles by Emulsion (Co)polymerization of Styrene and γ-Methacryloxypropyltrimethoxysilane. Macromolecules 2005. [DOI: 10.1021/ma050334e] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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124
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Lefebvre F, Poulin R. Life history constraints on the evolution of abbreviated life cycles in parasitic trematodes. J Helminthol 2005; 79:47-53. [PMID: 15831113 DOI: 10.1079/joh2004273] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abbreviations of the complex life cycle of trematodes, from three to two hosts, have occurred repeatedly and independently among trematode lineages. This is usually facultative and achieved via progenesis: following encystment in the second intermediate host, the metacercaria develops precociously into an egg-producing adult, bypassing the need to reach a definitive host. Given that it provides relatively cheap insurance against a shortage of definitive hosts, it is not clear why facultative progenesis has only evolved in a few taxa. Here a comparative approach is used to test whether progenetic trematodes are characterized by larger body size and egg volumes, two traits that correlate with other key life history features, than other trematodes. These traits may constrain the evolution of progenesis, because precocious maturation might be impossible when the size difference between the metacercaria and a reproductive adult is too large. First, trematode species belonging to genera in which progenesis has been documented were found not to differ significantly from other trematode species. Second, using within-genus paired comparisons across 19 genera in which progenesis has been reported, progenetic species did not differ, with respect to body size or egg size, from their non-progenetic congeners. Third, using intraspecific paired comparisons in species where progenesis is facultative, no difference was observed in the sizes of eggs produced by worms in both the intermediate and definitive host, suggesting that opting for progenesis does not influence the size of a worm's eggs. Overall, the lack of obvious differences in body or egg size between trematodes with truncated life cycles and those with the normal three-host cycle indicates that basic life history characteristics are not acting as constraints on the evolution of progenesis; trematodes of all sizes can do it. Why facultative progenesis is not more widespread remains a mystery.
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125
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Devassy BM, Shanbhag G, Lefebvre F, Böhringer W, Fletcher J, Halligudi S. Zirconia-supported phosphotungstic acid as catalyst for alkylation of phenol with benzyl alcohol. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.molcata.2004.12.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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