Éditeur(s) : HAL CCSD American Society of Tropical Medicine and Hygiene
Résumé : International audience
Anti-leishmaniasis drug resistance is a common problem worldwide. The aim of this study was to inventory the general in vitro level of sensitivity of Leishmania isolates circulating in French Guiana and to highlight potential in vitro pentamidine-resistant isolates. This sensitivity study was conducted on 36 patient-promastigote isolates for seven drugs (amphotericin B, azithromycin, fluconazole, meglumine antimoniate, miltefosine, paromomycin, and pentamidine) using the Cell Counting Kit-8 viability test. The IC50 values obtained were heterogeneous. One isolate exhibited high IC50 values for almost all drugs tested. Pentamidine, which is the first-line treatment in French Guiana, showed efficacy at very low doses (mean of 0.0038 μg/mL). The concordance of the in vitro pentamidine results with the patients' clinical outcomes was 94% (K = 0.82).
ISSN: 0002-9637

inserm-01481512
http://www.hal.inserm.fr/inserm-01481512
http://www.hal.inserm.fr/inserm-01481512/document
http://www.hal.inserm.fr/inserm-01481512/file/2017%2C%20Ginouves%20-%20In%20vitro%20sensitivity%20of%20cutaneous%20leishmania.pdf
DOI : 10.4269/ajtmh.16-0373

Éditeur(s) : HAL CCSD John Libbey Eurotext
Résumé : International audience
Chemical risk assessment is a tool used in decision-making processes concerning situations of scientific uncertainty. Approaches to risk assessment in occupational and environmental health share the same objective of risk prevention. Nevertheless, the methods for both differ depending on whether the goal is to enforce regulations or conduct expert assessments and studies. These differences are stronger in occupational health, for which regulations require risk assessments at the work station, to classify and prioritize exposure situations to implement occupational risk prevention strategies. Risk assessment thus has somewhat different meanings in occupational and environmental health. This article attempts to clarify the different terms used in the different contexts and to describe the similarities and differences of the two approaches.
ISSN: 1635-0421

hal-00936256
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00936256
DOI : 10.1684/ers.2013.0646

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Background: While it is known that cancer risk is related to area-level socioeconomic status, the extent to which these inequalities are explained by contextual effects is poorly documented especially for head and neck cancer. Methods: A case-control study, ICARE, included 2415 head and neck cancer cases and 3555 controls recruited between 2001 and 2007 from 10 French regions retrieved from a general cancer registry. Individual socioeconomic status was assessed using marital status, highest educational level and occupational social class. Area-level socioeconomic status was assessed using the French version of the European Deprivation Index (EDI). The relationship between both individual and area-based socioeconomic level and the risk of head and neck cancer was assessed by multilevel analyses. Results: A higher risk for head and neck cancer was found in divorced compared with married individuals (OR = 2.14, 95% CI = 1.78-2.57), for individuals with a basic school-leaving qualification compared with those with higher education (OR = 4.55 95% CI = 3.72-5.57), for manual workers compared with managers (OR = 4.91, 95% CI = 3.92-6.15) and for individuals living in the most deprived areas compared with those living in the most affluent ones (OR = 1.98, 95% CI = 1.64-2.41). The influence of area-level socioeconomic status measured by EDI remained after controlling for individual socioeconomic characteristics (OR = 1.51; 95% confidence interval: 1.23-1.85, p-value = 0.0003). Conclusions: The role of individual socioeconomic status in the risk of head and neck cancer is undeniable, although contextual effects of deprived areas also increase the susceptibility of individuals developing the disease. (C) 2017 Elsevier Ltd. All rights reserved.
ISSN: 1368-8375

hal-01578588
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01578588
DOI : 10.1016/j.oraloncology.2017.06.014
PUBMED : 28688682

Éditeur(s) : HAL CCSD John Libbey Eurotext
Résumé : International audience
French toxicological reference values (VTR) and French occupational exposure limit values (VLEP) are indicators that are widely used in risk assessment for, respectively, human and occupational health. Neither value can replace the other. However, the information obtained for one can be very useful for the other. We propose to clarify the fundamental differences and similarities between these two values. To achieve this, we review first their history and then the methods used to derive them; we conclude by proposing some improvements to harmonize them. A case study of formaldehyde illustrates our analysis.
ISSN: 1635-0421

hal-00936267
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00936267
DOI : 10.1684/ers.2013.0647

Éditeur(s) : HAL CCSD Wiley
Résumé : Plant germination and development depend upon a seed's successful dispersal into a suitable habitat and its ability to grow and survive within the surrounding biotic and abiotic environment. The seeds of Aechmea mertensii, a tank-bromeliad species, are dispersed by either Camponotus femoratus or Neoponera goeldii, two ant species that initiate ant gardens (AGs). These two mutualistic ant species influence the vegetative and reproductive traits of the bromeliad through their divergent ecological preferences (i.e. light and substrate). We hypothesised that the seeds dispersed by these two ant species have underlying genetic differences affecting germination, growth and survival of A.mertensii seedlings in different ways. To test this, we used an experimental approach consisting of sowing seeds of A.mertensii: (i) taken from the two AG-ant associations (i.e. seed origin), (ii) in two contrasting light conditions, and (iii) on three different substrates. Light and substrate had significant effects on germination, survival and on eight key leaf traits reflecting plant performance. Seed origin had a significant effect only on germination and on two leaf traits (total dry mass and relative growth rate). Overall, this bromeliad performs better (i.e. high growth and survival rates) when growing both in the shade and in the carton nest developed by C.femoratus ants. These results suggest that the plasticity of the tank bromeliad A.mertensii is mainly due to environment but also to genetic differences related to seed origin, as some traits are heritable. Thus, these two ant species may play contrasting roles in shaping plant evolution and speciation.
ISSN: 1435-8603

hal-01606565
https://hal.archives-ouvertes.fr/hal-01606565
DOI : 10.1111/plb.12452
PRODINRA : 407514

Éditeur(s) : HAL CCSD
Résumé : International audience
Human polycystic echinococcosis is a parasitic infection caused by the larval stage of Echinococcus vogeli which occurs in rural areas of Central and South America. Abdominal echinococcosis caused by E. vogeli is reported for the first time in a child, a 6-year-old boy in French Guiana. The diagnosis was made by histological and molecular techniques. In tropical regions, this neglected disease must be considered even in children.
ISSN: 2046-9047

hal-01484299
https://hal.univ-lorraine.fr/hal-01484299
DOI : 10.1179/2046905515Y.0000000054

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
The Southwest Indian Ocean (SWIO) is a striking marine biodiversity hotspot. Coral reefs in this region host a high proportion of endemics compared to total species richness and they are particularly threatened by human activities. The island archipelagos with their diverse marine habitats constitute a natural laboratory for studying diversification processes. Rocky shores in the SWIO region have remained understudied. This habitat presents a high diversity of molluscs, in particular gastropods. To explore the role of climatic and geological factors in lineage diversification within the genus Nerita, we constructed a new phylogeny with an associated chronogram from two mitochondrial genes [cytochrome oxidase sub-unit 1 and 16S rRNA], combining previously published and new data from eight species sampled throughout the region. All species from the SWIO originated less than 20 Ma ago, their closest extant relatives living in the Indo-Australian Archipelago (IAA). Furthermore, the SWIO clades within species with Indo-Pacific distribution ranges are quite recent, less than 5 Ma. These results suggest that the regional diversification of Nerita is closely linked to tectonic events in the SWIO region. The Reunion mantle plume head reached Earth's surface 67 Ma and has been stable and active since then, generating island archipelagos, some of which are partly below sea level today. Since the Miocene, sea-level fluctuations have intermittently created new rocky shore habitats. These represent ephemeral stepping-stones, which have likely facilitated repeated colonization by intertidal gastropods, like Nerita populations from the IAA, leading to allopatric speciation. This highlights the importance of taking into account past climatic and geological factors when studying diversification of highly dispersive tropical marine species. It also underlines the unique history of the marine biodiversity of the SWIO region.
ISSN: 1932-6203

hal-01185713
https://hal.archives-ouvertes.fr/hal-01185713
https://hal.archives-ouvertes.fr/hal-01185713/document
https://hal.archives-ouvertes.fr/hal-01185713/file/PLoS%20ONE%202014%20Postaire.pdf
DOI : 10.1371/journal.pone.0095040

Éditeur(s) : HAL CCSD Oxford University Press (OUP): Policy A1 - Oxford Open Option C
Résumé : International audience
BACKGROUND: Infections of renal grafts with Candida species can induce life-threatening complications in the recipient. METHODS: A 9-year retrospective study involving all of the transplant centers in France was designed to determine the incidence, origin, characteristics, and outcome of graft-site candidiasis that occurred after kidney transplantation. Yeasts cultured from preservation or drainage solutions and graft specimens were recorded. RESULTS: Among 18,617 kidney grafts, 18 recipients corresponding to 12 donors developed culture-confirmed graft-site candidiasis (incidence, 1 case per 1000 grafts) a median of 25 days after the graft procedure. Clinical presentations included 14 cases of renal arteritis (13 were complicated by aneurysm), 1 urinoma, 2 graft site abscesses, and 1 surgical site infection. Candida albicans was involved in 13 cases. A unique C. albicans genotype or a single rare Candida species was involved in each episode. Together with the clinical history, these findings demonstrate that organ contamination followed by transmission to the recipient occurred during recovery. Therapeutic management varied from simple monitoring in 1 case to a combination of surgery (nephrectomy in 9 cases and arterial bypass in 9 cases) and antifungal therapy (14 cases). Overall, 3 of 18 kidney transplant recipients died, and 9 had their graft surgically removed. CONCLUSION: Graft-transmitted candidiasis that ends most often in fungal arteritis is associated with high morbidity and mortality after kidney transplantation and is related to organ contamination during recovery in the donor.
Clinical Infectious Diseases

hal-00676313
https://hal.archives-ouvertes.fr/hal-00676313
DOI : 10.1086/595688
PUBMED : 19090753

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Signalling through the Wnt family of secreted proteins originated in a common metazoan ancestor and greatly influenced the evolution of animal body plans. In bilaterians, Wnt signalling plays multiple fundamental roles during embryonic development and in adult tissues, notably in axial patterning, neural development and stem cell regulation. Studies in various cnidarian species have particularly highlighted the evolutionarily conserved role of the Wnt/b-catenin pathway in specification and patterning of the primary embryonic axis. However in another key non-bilaterian phylum, Ctenophora, Wnts are not involved in early establishment of the body axis during embryogenesis. We analysed the expression in the adult of the ctenophore Pleurobrachia pileus of 11 orthologues of Wnt signalling genes including all ctenophore Wnt ligands and Fz receptors and several members of the intracellular b-catenin pathway machinery. All genes are strongly expressed around the mouth margin at the oral pole, evoking the Wnt oral centre of cnidarians. This observation is consistent with primary axis polarisation by the Wnts being a universal metazoan feature, secondarily lost in ctenophores during early development but retained in the adult. In addition, local expression of Wnt signalling genes was seen in various anatomical structures of the body including in the locomotory comb rows, where their complex deployment suggests control by the Wnts of local comb polarity. Other important contexts of Wnt involvement which probably evolved before the ctenophore/ cnidarian/bilaterian split include proliferating stem cells and progenitors irrespective of cell types, and developing as well as differentiated neuro-sensory structures.
ISSN: 1932-6203

hal-01544483
https://hal.archives-ouvertes.fr/hal-01544483
DOI : 10.1371/journal.pone.0084363

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Cancer cells display alterations in many cellular processes. One core hallmark of cancer is the Warburg effect which is a glycolytic reprogramming that allows cells to survive and proliferate. Although the contributions of environmental contaminants to cancer development are widely accepted, the underlying mechanisms have to be clarified. Benzo[a]pyrene (B[a]P), the prototype of polycyclic aromatic hydrocarbons, exhibits genotoxic and carcinogenic effects, and it is a human carcinogen according to the International Agency for Research on Cancer. In addition to triggering apoptotic signals, B[a]P may induce survival signals, both of which are likely to be involved in cancer promotion. We previously suggested that B[a]P-induced mitochondrial dysfunctions, especially membrane hyperpolarization, might trigger cell survival signaling in rat hepatic epithelial F258 cells. Here, we further characterized these dysfunctions by focusing on energy metabolism. We found that B[a]P promoted a metabolic reprogramming. Cell respiration decreased and lactate production increased. These changes were associated with alterations in the tricarboxylic acid cycle which likely involve a dysfunction of the mitochondrial complex II. The glycolytic shift relied on activation of the Na+/H+ exchanger 1 (NHE1) and appeared to be a key feature in B[a]P-induced cell survival related to changes in cell phenotype (epithelial-to-mesenchymal transition and cell migration).
ISSN: 2045-2322

Droits : http://creativecommons.org/licenses/by/
hal-01359569
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359569
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359569/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359569/file/The%20environmental%20carcinogen-CCBY%20%281%29.pdf
DOI : 10.1038/srep30776

Éditeur(s) : HAL CCSD
Résumé : International audience
The Black Curassow (Crax alector) is a large game bird with Vulnerable conservation status found in north-centralSouth America. We examined its distributional pattern across French Guiana using a large number of environmentaldescriptors at 3 scales of analysis: landscape, forest type, and microhabitat. We used a hierarchical model withtemporary emigration and imperfect detection for data collected by standard distance sampling methods at 35study sites. At the landscape scale, Black Curassow density decreased with hunting pressure and increased withsteeper slopes in both hunted and unhunted areas. Topography appeared to be a good proxy for Black Curassowecological requirements and probably reflected habitat quality. At the forest scale, population density wasnegatively correlated with the abundance of palms and Mimosoideae and positively correlated with the abundanceof Lauraceae. Botanical families did not directly influence Black Curassow distribution, but rather determined spatialpatterns by being markers of a particular forest type. At the microhabitat scale, Black Curassows used hilltops morefrequently than other parts of the local topographical gradient. Our multiscale analysis shows that this species’distribution can be explained by biotic or abiotic conditions, regardless of the scale. For conservation, werecommend maintaining connectivity between Black Curassow populations separated by hunted areas. Ourpredicted densities could be used to adapt hunting quotas across French Guiana’s forests. We show that combiningfield and remote sensing data helps to understand the ecological processes responsible for Black Curassow habitatrelationships.
The Condor Ornithological Applications

hal-01455653
https://hal.archives-ouvertes.fr/hal-01455653
https://hal.archives-ouvertes.fr/hal-01455653/document
https://hal.archives-ouvertes.fr/hal-01455653/file/condor-15-28.1.pdf
DOI : 10.1650/CONDOR-15-28.1

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Chronic liver damage due to viral or chemical agents leads to a repair process resulting in hepatic fibrosis. Fibrosis may lead to cirrhosis, which may progress to liver cancer or a loss of liver function, with an associated risk of liver failure and death. Chlordecone is a chlorinated pesticide used in the 1990s. It is not itself hepatotoxic, but its metabolism in the liver triggers hepatomegaly and potentiates hepatotoxic agents. Chlordecone is now banned, but it persists in soil and water, resulting in an ongoing public health problem in the Caribbean area. We assessed the probable impact of chlordecone on the progression of liver fibrosis in the population of contaminated areas, by developing a mouse model of chronic co-exposure to chlordecone and a hepatotoxic agent, carbon tetrachloride (CCl4). After repeated administrations of chlordecone and CCl4 by gavage over a 12-week period, we checked for liver damage in the exposed mice, by determining serum liver transaminase (AST, ALT) levels, histological examinations of the liver and measuring the expression of genes encoding extracellular matrix components. The co-exposure of mice to CCl4 and chlordecone resulted in significant increases in ALT and AST levels. Chlordecone also increased expression of the Col1A2, MMP-2, TIMP-1 and PAI-1 genes in CCl4-treated mice. Finally, we demonstrated, by quantifying areas of collagen deposition and alpha-SMA gene expression, that chlordecone potentiated the hepatic fibrosis induced by CCl4. In conclusion, our data suggest that chlordecone potentiates hepatic fibrosis in mice with CCl4-induced chronic liver injury
ISSN: 0378-4274

hal-01274228
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274228
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274228/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274228/file/Chlordecone%20potentiates%20hepatic%20fibrosis%20%281%29.pdf
DOI : 10.1016/j.toxlet.2016.02.005

Éditeur(s) : HAL CCSD American Society of Hematology
Résumé : International audience
Sickle cell disease is characterized by painful vaso-occlusive crises during which abnormal interactions between erythroid adhesion molecules and vessel-wall proteins are thought to play a critical role. Hydroxyurea, the only drug with proven benefit in sickle cell disease, diminishes these interactions, but its mechanism of action is not fully understood. We report that, under hydroxyurea, expression of the unique erythroid laminin receptor Lu/BCAM was increased, but red blood cell adhesion to laminin decreased. Because Lu/BCAM phosphorylation is known to activate cell adhesion to laminin, it was evaluated and found to be dramatically lower in hydroxyurea-treated patients. Analysis of the protein kinase A pathway showed decreased intracellular levels of the upstream effector cyclic adenosine monophosphate during hydroxyurea treatment. Using a cellular model expressing recombinant Lu/BCAM, we showed that hydroxyurea led to decreased intracellular cyclic adenosine monophosphate levels and diminished Lu/BCAM phosphorylation and cell adhesion. We provide evidence that hydroxyurea could reduce abnormal sickle red blood cell adhesion to the vascular wall by regulating the activation state of adhesion molecules independently of their expression level.
ISSN: 0006-4971

inserm-00821117
http://www.hal.inserm.fr/inserm-00821117
http://www.hal.inserm.fr/inserm-00821117/document
http://www.hal.inserm.fr/inserm-00821117/file/Bartolucci_Blood_2010.pdf
DOI : 10.1182/blood-2009-12-257444

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
DNA cytosine methylation is a widely conserved epigenetic mark in eukaryotes that appears to have critical roles in the regulation of genome structure and transcription. Genome-wide methylation maps have so far only been established from the supergroups Archaeplastida and Unikont. Here we report the first whole-genome methylome from a stramenopile, the marine model diatom Phaeodactylum tricornutum. Around 6% of the genome is intermittently methylated in a mosaic pattern. We find extensive methylation in transposable elements. We also detect methylation in over 320 genes. Extensive gene methylation correlates strongly with transcriptional silencing and differential expression under specific conditions. By contrast, we find that genes with partial methylation tend to be constitutively expressed. These patterns contrast with those found previously in other eukaryotes. By going beyond plants, animals and fungi, this stramenopile methylome adds significantly to our understanding of the evolution of DNA methylation in eukaryotes.
ISSN: 2041-1723

hal-01545322
https://hal.archives-ouvertes.fr/hal-01545322
DOI : 10.1038/ncomms3091

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The benefit of assimilating high spatial and temporal resolution Global Positioning System (GPS) zenith tropospheric delay (ZTD) observations within a high-resolution numerical weather prediction (NWP) system is evaluated during IOP 9 of the Convective and Orographically-induced Precipitation Study (COPS) campaign. In the framework of the international COPS field experiment, which took place from June to August 2007, a dense GPS network was deployed in the Vosges mountain region in eastern France and in the Black Forest region in southwestern Germany. GPS ZTD observations collected during the COPS field campaign, in addition to the European operational GPS data, are assimilated into the AROME/3D-Var system. We investigate the impact of assimilating these GPS ZTD observations on the forecast of convective systems that travelled over eastern France during the three days of COPS IOP 9 (18-20 July 2007). The results show a clear positive impact on short-range quantitative precipitation forecasts when GPS ZTD observations are assimilated. The impact is most important on 19 July 2007 (IOP 9b). The present study benefits from additional validation measurements collected during the COPS campaign. In particular we find that the assimilation of ZTD data induces changes in the low-to-middle tropospheric water vapour vertical structure that are consistent with water vapour measurements from radiosonde and airborne lidar. As most of the improvement is gained by assimilating GPS ZTD observations from the European operational GPS network, this study opens up encouraging horizons for the assimilation of GPS ZTD in new high-resolution operational NWP systems
ISSN: 0035-9009

hal-00424350
https://hal.archives-ouvertes.fr/hal-00424350
DOI : 10.1002/qj.508

Éditeur(s) : HAL CCSD Wiley
Résumé : While attention on logging in the tropics has been increasing, studies on the long-term effects of silviculture on forest dynamics and ecology remain scare and spatially limited. Indeed, most of our knowledge on tropical forests arises from studies carried out in undisturbed tropical forests. This bias is problematic given that logged and disturbed tropical forests are now covering a larger area than the so-called primary forests. A new network of permanent sample plots in logged forests, the Tropical managed Forests Observatory (TmFO), aims to fill this gap by providing unprecedented opportunities to examine long-term data on the resilience of logged tropical forests at regional and global scales. TmFO currently includes 24 experimental sites distributed across three tropical regions, with a total of 490 permanent plots and 921ha of forest inventories.
ISSN: 1402-2001

hal-01204230
https://hal.archives-ouvertes.fr/hal-01204230
DOI : 10.1111/avsc.12125
PRODINRA : 323838

Éditeur(s) : HAL CCSD Sociedade Entomológica do Brasil
Résumé : Variations in diel activity among hyperdiverse tropical communities of moths, despite representing a key component of niche partitioning between species, have barely been studied so far. Using light trapping from dawn to sunset over a 1-year period in French Guiana, we investigated these variations within and between two families of moths (Sphingidae and Saturniidae). Our results revealed contrasting patterns in flight activity at night between Sphingidae and Saturniidae. Sphingidae reached their peak in species richness and abundance between 7:00 and 8:00 p.m., followed by a decrease around 11:00 p.m. to midnight, whereas Saturniidae were continuously present throughout the night, with a peak around midnight. In addition, we found changes in diel activity among some of the most common genera in each family, highlighting distinct behavioral, physiological, and functional traits among taxa. Given differences in flight activity at different taxonomic levels, it is strongly recommended to monitor by light trapping throughout the night to effectively sample saturniid and sphingid assemblages, even though the activity of Sphingidae sharply declines after midnight. These results improve the general natural history information of tropical moths and reinforce the need of further research on the ecological and taxonomic consequences of differences in diel activity.
ISSN: 1519-566X

hal-01536447
https://hal.archives-ouvertes.fr/hal-01536447
DOI : 10.1007/s13744-014-0264-3
PRODINRA : 320714