Européens et prédateurs exotiques en Indochine, le cas du tigre

[Jean-Marc Moriceau, Philippe Madeline (dir.)- en savoir plus sur l'ouvrage : http://www.unicaen.fr/puc/spip.php?article802 (consulté le 26/04/2011)]L'expansion coloniale du XIXe siècle amène les Européens à s'installer dans des territoires qui leur étaient très largement inconnus. Là, ils se trouvent face à une nature et une faune souvent perçue comme hostiles et dangereuses. Entre 1858 et 1897-1898, les Français prennent pied dans la péninsule indochinoise et y établissent une Union composée notamment de la Cochinchine, du Cambodge, du Tonkin de l'Annam et du Laos. Le système de domination en place, une société coloniale, essentiellement urbaine, se développe ; mais " la brousse " avec ses secrets et ses dangers joue encore un rôle important dans l'imaginaire des Français d'Indochine. Là, l'archétype du prédateur exotique est le tigre (Panthera tigris corbetti), figure emblématique d'une jungle fantasmée : Ong Cop, le seigneur tigre. Nous chercherons ici à étudier les relations homme-tigre en Indochine, en insistant sur la partie méridionale, Cambodge, Cochinchine et sud de l'Annam. Nous verrons comment les Français ont réagi à la présence du tigre et quelles ont été les conséquences de la colonisation européenne pour les rapports entre l'homme et l'animal

Cellular Immune Responses Induced with Dose-Sparing Intradermal Administration of HIV Vaccine to HIV-Uninfected Volunteers in the ANRS VAC16 Trial

The objective was to compare the safety and cellular immunogenicity of intradermal versus intramuscular immunization with an HIV-lipopeptide candidate vaccine (LIPO-4) in healthy volunteers.A randomized, open-label trial with 24 weeks of follow-up was conducted in France at six HIV-vaccine trial sites. Sixty-eight healthy 21- to 55-year-old HIV-uninfected subjects were randomized to receive the LIPO-4 vaccine (four HIV lipopeptides linked to a T-helper-stimulating epitope of tetanus-toxin protein) at weeks 0, 4 and 12, either intradermally (0.1 ml, 100 microg of each peptide) or intramuscularly (0.5 ml, 500 microg of each peptide). Comparative safety of both routes was evaluated. CD8+ T-cell immune responses to HIV epitopes (ELISpot interferon-gamma assay) and tetanus toxin-specific CD4+ T-cell responses (lymphoproliferation) were assessed at baseline, two weeks after each injection, and at week 24.No severe, serious or life-threatening adverse events were observed. Local pain was significantly more frequent after intramuscular injection, but local inflammatory reactions were more frequent after intradermal immunization. At weeks 2, 6, 14 and 24, the respective cumulative percentages of induced CD8+ T-cell responses to at least one HIV peptide were 9, 33, 39 and 52 (intradermal group) or 14, 20, 26 and 37 (intramuscular group), and induced tetanus toxin-specific CD4+ T-cell responses were 6, 27, 33 and 39 (intradermal), or 9, 46, 54 and 63 (intramuscular). In conclusion, intradermal LIPO-4 immunization was well tolerated, required one-fifth of the intramuscular dose, and induced similar HIV-specific CD8+ T-cell responses. Moreover, the immunization route influenced which antigen-specific T-cells (CD4+ or CD8+) were induced.ClinicalTrials.gov NCT00121121

Inferring within-flock transmission dynamics of highly pathogenic avian influenza H5N8 virus in France, 2020.

Following the emergence of highly pathogenic avian influenza (H5N8) in France in early December 2020, we used duck mortality data from the index farm to investigate within-flock transmission dynamics. A stochastic epidemic model was fitted to the daily mortality data and model parameters were estimated using an approximate Bayesian computation sequential Monte Carlo (ABC-SMC) algorithm. The model predicted that the first bird in the flock was infected 5 days (95% credible interval, CI: 3-6) prior to the day of suspicion and that the transmission rate was 4.1 new infections per day (95% CI: 2.8-5.8). On average, ducks became infectious 4.1 h (95% CI: 0.7-9.1) after infection and remained infectious for 4.3 days (95% CI: 2.8-5.7). The model also predicted that 34% (50% prediction interval: 8%-76%) of birds would already be infectious by the day of suspicion, emphasizing the substantial latent threat this virus could pose to other poultry farms and to neighbouring wild birds. This study illustrates how mechanistic models can help provide rapid relevant insights that contribute to the management of infectious disease outbreaks of farmed animals. These methods can be applied to future outbreaks and the resulting parameter estimates made available to veterinary services within a few hours

Genome sequencing of Xanthomonas axonopodis pv. phaseoli CFBP4834-R reveals that flagellar motility is not a general feature of xanthomonads.

Xanthomonads are plant-associated bacteria that establish neutral, commensal or pathogenic relationships with plants. The list of common characteristics shared by all members of the genus Xanthomonas is now well established based on the entire genome sequences that are currently available and that represent various species, numerous pathovars of X. axonopodis (sensu Vauterin et al., 2000), X. oryzae and X. campestris, and many strains within some pathovars. These ?-proteobacteria are motile by a single polar flagellum. Motility is an important feature involved in biofilm formation, plant colonization and hence considered as a pathogenicity factor. X. axonopodis pv. phaseoli var. fuscans (Xapf) is one of the causal agents of common bacterial blight of bean and 4834-R is a highly aggressive strain of this pathogen that was isolated from a seed-borne epidemic in France in 1998. We obtained a high quality assembled sequence of the genome of this strain with 454-Solexa and 2X Sanger sequencing. Housekeeping functions are conserved in this genome that shares core characteristics with genomes of other xanthomonads: the six secretion systems which have been described so far in Gram negative bacteria are all present, as well as their ubiquitous substrates or effectors and a rather usual number of mobile elements. Elements devoted to the adaptation to the environment constitute an important part of the genome with a chemotaxis island and dispersed MCPs, numerous two-component systems, and numerous TonB dependent transporters. Furthermore, numerous multidrug efflux systems and functions dedicated to biofilm formation that confer resistance to stresses are also present. An intriguing feature revealed by genome analysis is a long deletion of 35 genes (33 kbp) involved in flagellar biosynthesis. This deletion is replaced by an insertion sequence called ISXapf2. Genes such as flgB to flgL and fliC to fleQ which are involved in the flagellar structure (rod, P- and L-ring, hook, cap and filament) are absent in the genome of strain 4834-R that is not motile. Primers were designed to detect this deletion by PCR in a collection of more than 300 strains representing different species and pathovars of Xanthomonas, and less than 5% of the tested xanthomonads strains were found nonmotile because of a deletion in the flagellum gene cluster. We observed that half of the Xapf strains isolated from the same epidemic than strain 4834-R was non-motile and that this ratio was conserved in the strains colonizing the next bean seed generation. Isolation of such variants in a natural epidemic reveals that either flagellar motility is not a key function for fitness or that some complementation occurs within the bacterial population. (Résumé d'auteur

LIPH Expression in Skin and Hair Follicles of Normal Coat and Rex Rabbits

Natural mutations in the LIPH gene were shown to be responsible for hair growth defects in humans and for the rex short hair phenotype in rabbits. In this species, we identified a single nucleotide deletion in LIPH (1362delA) introducing a stop codon in the C-terminal region of the protein. We investigated the expression of LIPH between normal coat and rex rabbits during critical fetal stages of hair follicle genesis, in adults and during hair follicle cycles. Transcripts were three times less expressed in both fetal and adult stages of the rex rabbits than in normal rabbits. In addition, the hair growth cycle phases affected the regulation of the transcription level in the normal and mutant phenotypes differently. LIPH mRNA and protein levels were higher in the outer root sheath (ORS) than in the inner root sheath (IRS), with a very weak signal in the IRS of rex rabbits. In vitro transfection shows that the mutant protein has a reduced lipase activity compared to the wild type form. Our results contribute to the characterization of the LIPH mode of action and confirm the crucial role of LIPH in hair production

OA04-01. Safety and immunogenicity of LIPO-5, a HIV-1 lipopeptide vaccine: results of ANRS VAC18, a phase 2, randomized, double-blind, placebo-controlled trial

International audiencen.

Patent Foramen Ovale Closure or Anticoagulation vs. Antiplatelets after Stroke

BACKGROUND Trials of patent foramen ovale (PFO) closure to prevent recurrent stroke have been inconclusive. We investigated whether patients with cryptogenic stroke and echocardiographic features representing risk of stroke would benefit from PFO closure or anticoagulation, as compared with antiplatelet therapy. METHODS In a multicenter, randomized, open-label trial, we assigned, in a 1:1:1 ratio, patients 16 to 60 years of age who had had a recent stroke attributed to PFO, with an associated atrial septal aneurysm or large interatrial shunt, to transcatheter PFO closure plus long-term antiplatelet therapy (PFO closure group), antiplatelet therapy alone (antiplatelet-only group), or oral anticoagulation (anticoagulation group) (randomization group 1). Patients with contraindications to anticoagulants or to PFO closure were randomly assigned to the alternative noncontraindicated treatment or to antiplatelet therapy (randomization groups 2 and 3). The primary outcome was occurrence of stroke. The comparison of PFO closure plus antiplatelet therapy with antiplatelet therapy alone was performed with combined data from randomization groups 1 and 2, and the comparison of oral anticoagulation with antiplatelet therapy alone was performed with combined data from randomization groups 1 and 3. RESULTS A total of 663 patients underwent randomization and were followed for a mean (+/- SD) of 5.3 +/- 2.0 years. In the analysis of randomization groups 1 and 2, no stroke occurred among the 238 patients in the PFO closure group, whereas stroke occurred in 14 of the 235 patients in the antiplatelet-only group (hazard ratio, 0.03; 95% confidence interval, 0 to 0.26; P<0.001). Procedural complications from PFO closure occurred in 14 patients (5.9%). The rate of atrial fibrillation was higher in the PFO closure group than in the antiplatelet-only group (4.6% vs. 0.9%, P = 0.02). The number of serious adverse events did not differ significantly between the treatment groups (P = 0.56). In the analysis of randomization groups 1 and 3, stroke occurred in 3 of 187 patients assigned to oral anticoagulants and in 7 of 174 patients assigned to antiplatelet therapy alone. CONCLUSIONS Among patients who had had a recent cryptogenic stroke attributed to PFO with an associated atrial septal aneurysm or large interatrial shunt, the rate of stroke recurrence was lower among those assigned to PFO closure combined with antiplatelet therapy than among those assigned to antiplatelet therapy alone. PFO closure was associated with an increased risk of atrial fibrillation

A Deletion in Exon 9 of the LIPH Gene Is Responsible for the Rex Hair Coat Phenotype in Rabbits (Oryctolagus cuniculus)

The fur of common rabbits is constituted of 3 types of hair differing in length and diameter while that of rex animals is essentially made up of amazingly soft down-hair. Rex short hair coat phenotypes in rabbits were shown to be controlled by three distinct loci. We focused on the “r1” mutation which segregates at a simple autosomal-recessive locus in our rabbit strains. A positional candidate gene approach was used to identify the rex gene and the corresponding mutation. The gene was primo-localized within a 40 cM region on rabbit chromosome 14 by genome scanning families of 187 rabbits in an experimental mating scheme. Then, fine mapping refined the region to 0.5 cM (Z = 78) by genotyping an additional 359 offspring for 94 microsatellites present or newly generated within the first defined interval. Comparative mapping pointed out a candidate gene in this 700 kb region, namely LIPH (Lipase Member H). In humans, several mutations in this major gene cause alopecia, hair loss phenotypes. The rabbit gene structure was established and a deletion of a single nucleotide was found in LIPH exon 9 of rex rabbits (1362delA). This mutation results in a frameshift and introduces a premature stop codon potentially shortening the protein by 19 amino acids. The association between this deletion and the rex phenotype was complete, as determined by its presence in our rabbit families and among a panel of 60 rex and its absence in all 60 non-rex rabbits. This strongly suggests that this deletion, in a homozygous state, is responsible for the rex phenotype in rabbits