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International audience; Analysis of the incisor enamel microstructure of extinct and extant West Indian caviomorph rodents emphasizes a clear microstructural distinction between the Echimyidae (Capromyinae and Heteropsomyinae) among Octodontoidea and the "Heptaxodontidae" whose phylogenetic affinities are debated. All capromyines and heteropsomyines have a pattern of enamel characterized by a rectangular crystallite arrangement, which is biomechanically strongest in limiting crack propagation most efficiently (subtype [Sbt.] 3 of multiserial Hunter-Schreger bands [HSBs]). This enamel condition is exclusive to all mainland octodontoids. In stark contrast, “heptaxodontids” sampled here exhibit much less derived enamel subtypes of multiserial HSBs with parallel to acute angular crystallite arrangement (Sbt. 1 [Clidomys], Sbt. 1–2 [Elasmodontomys], and low acute Sbt. 2 [Amblyrhiza]), less well adapted for prevention of crack propagation. The incisor enamel microstructure of Amblyrhiza and Clidomys is consistent with a chinchilloid assignment, as reflected by the anatomy of their auditory region and their unusual dental pattern. For Elasmodontomys, the primitive condition of its incisor enamel is difficult to reconcile with its highly nested phylogenetic position within the Octodontoidea clade (among the Capromyinae), as recently inferred from aDNA analyses. The different enamel patterns among extinct and extant West Indian caviomorphs indicate distinct high-level taxonomic groups, but restricted to the Octochinchilloi (Octodontoidea and Chinchilloidea) among Caviomorpha. The great diversity of caviomorphs on the Caribbean islands resulted from intra-archipelago diversification through time, but their high-level phylogenetic diversity can only be explained by distinct sources, implying de facto multiple (potentially time-staggered) natural colonizations of the West Indies. The chinchilloid-compatible enamel and dental pattern characterizing Borikenomys from lower Oligocene deposits in Puerto Rico, strongly suggest a link with some of the recently-extinct "heptaxodontids" that would substantiate their much greater antiquity in the Caribbean islands.

International audience; Saint Barthélemy is the only island of the northern Lesser Antilles where it is possible to investigate in the detail the chronostratigraphy of the mixed carbonate-volcaniclastic deposits of the Paleogene Caribbean volcanic arc. Based on field mapping and new biostratigraphical and sedimentological data, we study the limestone units interbedded in the Paleogene volcaniclastic deposits. We find that four main carbonate units occur instead of previously believed six ones. Based on the ages given by the foraminifera assemblages, and taking into account the recently published 40Ar/39Ar ages of magmatic rocks, the Lower Limestone unit dates Lutetian, the Intermediate Limestone unit late (?) Bartonian-late Priabonian, the Upper Limestone late Priabonian and the Top Limestone unit early Miocene. The Paleogene carbonate beds were deposited on gently dipping submarine volcaniclastic deposits issued from emergent volcanoes, in muddy, unrimmed inner to mid-ramp setting dominated by bottom communities. A major subaerial unconformity is evidenced during the Oligocene, most probably corresponding to uplift affecting Saint Barthélemy. Our work offers a revised lithostratigraphic succession of Saint Barthélemy as a first key-point for further studies of the Paleogene Caribbean arc deposits which were dismembered following the entrance of the Bahamas Bank in the Lesser Antilles subduction zone.

Background Identifying determinants for histologically proven high-grade anal intraepithelial lesions (hHSIL) in HIV-positive MSM would allow better targeted screening. Methods APACHES is a prospective study of anal HPV and related-lesions in 513 HIV-positive MSM aged ≥35 in six clinics across France. At baseline, participants underwent high resolution anoscopy (HRA) with biopsy of suspicious lesions, preceded by anal swabs for liquid-based cytology, p16/Ki67 immunostaining, and HPV DNA. hHSIL diagnosis was established by histopathological review panel consensus, and determinants assessed by logistic regression. Results Baseline hHSIL prevalence was 10.4% and did not differ significantly by age, sexual behaviour or any HIV/immunodeficiency markers. hHSIL prevalence was significantly elevated in participants that smoked (ORadj=2.6, 95%CI 1.3–5.5) or who, in concurrent anal swabs, had ASCUS/LSIL (3.6, 95% CI 1.4–9.3) or ASC-H/HSIL (22.2, 95% CI 6.8–72.6) cytologic abnormalities, p16/Ki67 dual positivity (3.4, 95%CI 1.5–7.5), or non16-HR HPV (13.0, 95%CI 1.7–102), but most notably, HPV16 (46.3, 6.1–355) infection. Previous diagnosis of low- (2.3, 95%CI 1.0–5.4) or high- (3.8, 95%CI 1.5–9.9) grade anal lesion also conveyed higher hHSIL risk. After controlling for patient-specific determinants, there remained significant clinic-specific effects, especially in higher risk groups (HPV16-positive participants: 31.3% hHSIL in clinics A-D versus 5.1% in clinics E-F, p Conclusions Anal cytology and HPV16 infection are potentially useful determinants of hHSIL risk in HIV-positive MSM, but HIV/immunodeficiency-related variables appear not to be.

Although the incidence of syphilis is increasing, liver involvement in tertiary syphilis remains exceptional. We report a case of tertiary syphilis revealed by liver localization. The clinical picture was misleading, mimicking multinodular hepatic metastasis. The final diagnosis was suspected following a fine-needle ultrasound-guided biopsy of a liver nodule showing granulomas as well as acellular necrosis and confirmed by positive serum syphilitic reactions and the presence of spirochetes in the liver. The outcome was uneventful following antibiotic treatment. It is important to be aware of the misleading picture of the disease, which has a favorable prognosis provided that simple treatment is rapidly initiated.