Global phylogeography of sailfish: deep evolutionary lineages with implications for fisheries management

Hydrobiologia - Since the Miocene profound climatic changes have influenced the biology and ecology of species worldwide, such as their connectivity, genetic population structure, and biogeography....     

Two Doses of Candidate TB Vaccine MVA85A in Antiretroviral Therapy (ART) Na?ve Subjects Gives Comparable Immunogenicity to One Dose in ART+ Subjects

Tuberculosis (TB) is a global public health problem exacerbated by the HIV epidemic. Here we evaluate a candidate TB vaccine, MVA85A, in a Phase I study in HIV-infected adults in Senegal. 24 patients were enrolled: Group 1∶12, antiretroviral therapy (ART) naïve, adults, with CD4 counts >300 and HIV RNA load <100 000 copies/ml. Group 2∶12 adults, stable on ART, with CD4 counts >300, and an undetectable HIV RNA load. Safety was evaluated by occurrence of local and systemic adverse events (AEs) and by monitoring of CD4 count, HIV RNA load, haematology and biochemistry. Immunogenicity was evaluated by ex-vivo interferon-gamma ELISpot assay. 87.7% of AEs were mild; 11.6% were moderate; and 0.7% were severe. 29.2% of AEs were systemic; 70.8% were expected local AEs. There were no vaccine-related Serious Adverse Events (SAEs) or clinically significant effects on HIV RNA load or CD4 count. In ART naive subjects, the first MVA85A immunisation induced a significant immune response at 1 and 4 weeks post-immunisation, which contracted to baseline by 12 weeks. Durability of immunogenicity in subjects on ART persisted out to 24 weeks post-vaccination. A second dose of MVA85A at 12 months enhanced immunogenicity in ART naïve subjects. Subjects on ART had higher responses after the first vaccination compared with ART naïve subjects; responses were comparable after 2 immunisations. In conclusion, MVA85A is well-tolerated and immunogenic in HIV-infected subjects in Senegal. A two dose regimen in ART naïve subjects is comparable in immunogenicity to a single dose in subjects on ART.Clinicaltrials.gov trial identifier {"type":"clinical-trial","attrs":{"text":"NCT00731471","term_id":"NCT00731471"}}NCT00731471.     

CoOOH nanosheet electrodes: Simple fabrication for sensitive electrochemical sensing of hydrogen peroxide and hydrazine

Cobalt oxyhydroxide, CoOOH, nanosheets were prepared via a surface alkaline treatment of cobalt foil at room temperature without using templates and catalysts. The morphology, chemical composition and structures of the nanosheets were characterized by XRD, FTIR and Raman spectroscopy, FESEM and TEM. These oriented and nanostructured arrays can be used directly as electrodes, thus simplifying the electrode fabrication process, as well as offering advantages such as enhanced electrode-electrolyte contact area, minimum diffusion resistance and direct active material-current collector connection for fast electron transport. The electrode was used as an electrochemical sensor towards non-enzymatic detection of hydrogen peroxide and hydrazine in alkaline solution. The amperometric detection of H(2)O(2) and N(2)H(4) was carried out at low potential (0V and 0.1V). At 0.1V, the amperometric signals are linearly proportional to H(2)O(2) concentration up to 1.6mM (R(2)=0.995), showing a detection limit (S/N=3) of 40μM and a high sensitivity of 99μAmM(-1)cm(-2). For N(2)H(4), the amperometric signals are linearly proportional to concentration up to 1.2mM (R(2)=0.99), showing a detection limit (S/N=3) of 20μM and a high sensitivity of 155μAmM(-1)cm(-2) at 0.1V.     

Role of human immunodeficiency virus (HIV)-specific T-cell immunity in control of dual HIV-1 and HIV-2 infection

Progressive immune dysfunction and AIDS develop in most cases of human immunodeficiency virus type 1 (HIV-1) infection but in only 25 to 30% of persons with HIV-2 infection. However, the natural history and immunologic responses of individuals with dual HIV-1 and HIV-2 infection are largely undefined. Based on our previous findings, we hypothesized that among patients with dual infection the control of HIV-1 is associated with the ability to respond to HIV-2 Gag epitopes and to maintain HIV-specific CD4⁺ T-cell responses. To test this, we compared the HIV-specific ex vivo IFN-γ enzyme-linked immunospot (ELISPOT) assay responses of 19 dually infected individuals to those of persons infected with HIV-1 or HIV-2 only. Further, we assessed the functional profile of HIV Gag-specific CD4⁺ and CD8⁺ T cells from nine HIV dually infected patients by using a multicolor intracellular cytokine staining assay. As determined by ELISPOT assay, the magnitude and frequency of IFN-γ-secreting T-cell responses to gene products of HIV-1 were higher than those to gene products of HIV-2 (2.64 versus 1.53 log₁₀ IFN-γ spot-forming cells/10⁶ cells [90% versus 63%, respectively].) Further, HIV-1 Env-, Gag-, and Nef- and HIV-2 Gag-specific responses were common; HIV-2 Nef-specific responses were rare. HIV-specific CD4⁺ T helper responses were detected in nine of nine dually infected subjects, with the majority of these T cells producing gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) and, to a lesser extent, interleukin-2. The HIV-1 plasma viral load was inversely correlated with HIV-2 Gag-specific IFN-γ-/TNF-α-secreting CD4⁺ and HIV-2 Gag-specific IFN-γ-secreting CD8⁺ T cells. In conclusion, the T-cell memory responses associated with containment of single HIV-1 and HIV-2 infection play a similar significant role in the immune control of dual HIV-1 and HIV-2 infection.     

Diversity of Toxoplasma gondii strains shaped by commensal communities of small mammals

Commensal rodent species are key reservoirs for Toxoplasma gondii in the domestic environment. In rodents, different T. gondii strains show variable patterns of virulence according to host species. Toxoplasma gondii strains causing non-lethal chronic infections in local hosts will be more likely to persist in a given environment, but few studies have addressed the possible role of these interactions in shaping the T. gondii population structure. In addition, the absence of validated techniques for upstream detection of T. gondii chronic infection in wild rodents hinders exploration of this issue under natural conditions. In this study, we took advantage of an extensive survey of commensal small mammals in three coastal localities of Senegal, with a species assemblage constituted of both native African species and invasive species. We tested 828 individuals for T. gondii chronic infection using the modified agglutination test for antibody detection in serum samples and a quantitative PCR assay for detection of T. gondii DNA in brain samples. The infecting T. gondii strains were genotyped whenever possible by the analysis of 15 microsatellite markers. We found (i) a very poor concordance between molecular detection and serology in the invasive house mouse, (ii) significantly different levels of prevalence by species and (iii) the autochthonous T. gondii Africa 1 lineage strains, which are lethal for laboratory mice, only in the native African species of commensal small mammals. Overall, this study highlights the need to reconsider the use of MAT serology in natural populations of house mice and provides the first known data about T. gondii genetic diversity in invasive and native species of small mammals from Africa. In light of these results, we discuss the role of invasive and native species, with their variable adaptations to different T. gondii strains, in shaping the spatial structure of T. gondii genetic diversity in Africa.     

Unravelling biodiversity,evolution and threats to conservation in the Sahara‐Sahel

Deserts and arid regions are generally perceived as bare and rather homogeneous areas of low diversity. The Sahara is the largest warm desert in the world and together with the arid Sahel displays high topographical and climatic heterogeneity, and has experienced recent and strong climatic oscillations that have greatly shifted biodiversity distribution and community composition. The large size, remoteness and long‐term political instability of the Sahara‐Sahel, have limited knowledge on its biodiversity. However, over the last decade, there have been an increasing number of published scientific studies based on modern geomatic and molecular tools, and broad sampling of taxa of these regions. This review tracks trends in knowledge about biodiversity patterns, processes and threats across the Sahara‐Sahel, and anticipates needs for biodiversity research and conservation. Recent studies are changing completely the perception of regional biodiversity patterns. Instead of relatively low species diversity with distribution covering most of the region, studies now suggest a high rate of endemism and larger number of species, with much narrower and fragmented ranges, frequently limited to micro‐hotspots of biodiversity. Molecular‐based studies are also unravelling cryptic diversity associated with mountains, which together with recent distribution atlases, allows identifying integrative biogeographic patterns in biodiversity distribution. Mapping of multivariate environmental variation (at 1 km × 1 km resolution) of the region illustrates main biogeographical features of the Sahara‐Sahel and supports recently hypothesised dispersal corridors and refugia. Micro‐scale water‐features present mostly in mountains have been associated with local biodiversity hotspots. However, the distribution of available data on vertebrates highlights current knowledge gaps that still apply to a large proportion of the Sahara‐Sahel. Current research is providing insights into key evolutionary and ecological processes, including causes and timing of radiation and divergence for multiple taxa, and associating the onset of the Sahara with diversification processes for low‐mobility vertebrates. Examples of phylogeographic patterns are showing the importance of allopatric speciation in the Sahara‐Sahel, and this review presents a synthetic overview of the most commonly hypothesised diversification mechanisms. Studies are also stressing that biodiversity is threatened by increasing human activities in the region, including overhunting and natural resources prospection, and in the future by predicted global warming. A representation of areas of conflict, landmines, and natural resources extraction illustrates how human activities and regional insecurity are hampering biodiversity research and conservation. Although there are still numerous knowledge gaps for the optimised conservation of biodiversity in the region, a set of research priorities is provided to identify the framework data needed to support regional conservation planning.     

Evaluation of coagulation activation after Rhinovirus infection in patients with asthma and healthy control subjects: an observational study

Background

Asthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance.

Methods

28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation).

Results

13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01).Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1.

Conclusions

Experimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load.

Trial registration

This trial was registered at the Dutch trial registry (http://www.trialregister.nl): NTR1677.     

Shifts in Mycobacterial Populations and Emerging Drug-Resistance in West and Central Africa

In this study, we retrospectively analysed a total of 605 clinical isolates from six West or Central African countries (Benin, Cameroon, Central African Republic, Guinea-Conakry, Niger and Senegal). Besides spoligotyping to assign isolates to ancient and modern mycobacterial lineages, we conducted phenotypic drug-susceptibility-testing for each isolate for the four first-line drugs. We showed that phylogenetically modern Mycobacterium tuberculosis strains are more likely associated with drug resistance than ancient strains and predict that the currently ongoing replacement of the endemic ancient by a modern mycobacterial population in West/Central Africa might result in increased drug resistance in the sub-region.     

Maternal and Perinatal Outcomes by Mode of Delivery in Senegal and Mali: A Cross-Sectional Epidemiological Survey

Objective

In the context of rapid changes regarding practices related to delivery in Africa, we assessed maternal and perinatal adverse outcomes associated with the mode of delivery in 41 referral hospitals of Mali and Senegal.

Study Design

Cross-sectional survey nested in a randomised cluster trial (1/10/2007–1/10/2008). The associations between intended mode of delivery and (i) in-hospital maternal mortality, (ii) maternal morbidity (transfusion or hysterectomy), (iii) stillbirth or neonatal death before Day 1 and (iv) neonatal death between 24 hours after birth and hospital discharge were examined. We excluded women with immediate life threatening maternal or fetal complication to avoid indication bias. The analyses were performed using hierarchical logistic mixed models with random intercept and were adjusted for women''s, newborn''s and hospitals'' characteristics.

Results

Among the 78,166 included women, 2.2% had a pre-labor cesarean section (CS) and 97.8% had a trial of labor. Among women with a trial of labor, 87.5% delivered vaginally and 12.5% had intrapartum CS. Pre-labor CS was associated with a marked reduction in the risk of stillbirth or neonatal death before Day 1 as compared with trial of labor (OR = 0.2 [0.16–0.36]), though we did not show that maternal mortality (OR = 0.3 [0.07–1.32]) and neonatal mortality after Day 1 (OR = 1.3 (0.66–2.72]) differed significantly between groups. Among women with trial of labor, intrapartum CS and operative vaginal delivery were associated with higher risks of maternal mortality and morbidity, and neonatal mortality after Day 1, as compared with spontaneous vaginal delivery.

Conclusions

In referral hospitals of Mali and Senegal, pre-labor CS is a safe procedure although intrapartum CS and operative vaginal delivery are associated with increased risks in mothers and infants. Further research is needed to determine what aspects of obstetric care contribute to a delay in the provision of intrapartum interventions so that practices may be made safer when they are needed.     

Reduced quantitative ultrasound bone mineral density in HIV-infected patients on antiretroviral therapy in Senegal

Background

Bone status in HIV-infected patients on antiretroviral treatment (ART) is poorly documented in resource-limited settings. We compared bone mineral density between HIV-infected patients and control subjects from Dakar, Senegal.

Methods

A total of 207 (134 women and 73 men) HIV-infected patients from an observational cohort in Dakar (ANRS 1215) and 207 age- and sex-matched controls from the general population were enrolled. Bone mineral density was assessed by quantitative ultrasound (QUS) at the calcaneus, an alternative to the reference method (i.e. dual X-absorptiometry), often not available in resource-limited countries.

Results

Mean age was 47.0 (±8.5) years. Patients had received ART for a median duration of 8.8 years; 45% received a protease inhibitor and 27% tenofovir; 84% had undetectable viral load. Patients had lower body mass index (BMI) than controls (23 versus 26 kg/m², P<0.001). In unadjusted analysis, QUS bone mineral density was lower in HIV-infected patients than in controls (difference: −0.36 standard deviation, 95% confidence interval (CI): −0.59;−0.12, P = 0.003). Adjusting for BMI, physical activity, smoking and calcium intake attenuated the difference (−0.27, CI: −0.53;−0.002, P = 0.05). Differences in BMI between patients and controls explained a third of the difference in QUS bone mineral density. Among patients, BMI was independently associated with QUS bone mineral density (P<0.001). An association between undetectable viral load and QUS bone density was also suggested (β = 0.48, CI: 0.02;0.93; P = 0.04). No association between protease inhibitor or tenofovir use and QUS bone mineral density was found.

Conclusion

Senegalese HIV-infected patients had reduced QUS bone mineral density in comparison with control subjects, in part related to their lower BMI. Further investigation is needed to clarify the clinical significance of these observations.