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Clémentine Schilte Frédérik Staikovsky Thérèse Couderc Yoann Madec Florence Carpentier Somar Kassab Matthew L. Albert Marc Lecuit Alain Michault 《PLoS neglected tropical diseases》2013,7(3)
Background
Arthritogenic alphaviruses, including Chikungunya virus (CHIKV), are responsible for acute fever and arthralgia, but can also lead to chronic symptoms. In 2006, a Chikungunya outbreak occurred in La Réunion Island, during which we constituted a prospective cohort of viremic patients (n = 180) and defined the clinical and biological features of acute infection. Individuals were followed as part of a longitudinal study to investigate in details the long-term outcome of Chikungunya.Methodology/Principal Findings
Patients were submitted to clinical investigations 4, 6, 14 and 36 months after presentation with acute CHIKV infection. At 36 months, 22 patients with arthralgia and 20 patients without arthralgia were randomly selected from the cohort and consented for blood sampling. During the 3 years following acute infection, 60% of patients had experienced symptoms of arthralgia, with most reporting episodic relapse and recovery periods. Long-term arthralgias were typically polyarthralgia (70%), that were usually symmetrical (90%) and highly incapacitating (77%). They were often associated with local swelling (63%), asthenia (77%) or depression (56%). The age over 35 years and the presence of arthralgia 4 months after the disease onset are risk factors of long-term arthralgia. Patients with long-term arthralgia did not display biological markers typically found in autoimmune or rheumatoid diseases. These data helped define the features of CHIKV-associated chronic arthralgia and permitted an estimation of the economic burden associated with arthralgia.Conclusions/Significance
This study demonstrates that chronic arthralgia is a frequent complication of acute Chikungunya disease and suggests that it results from a local rather than systemic inflammation. 相似文献4.
Anatomical and molecular characters used to differentiate populations of the land snail Cornu aspersum (Helix aspersa) exhibit, in the western Mediterranean, definite and concordant patterns of correlation with geography. Scenarios involving Pliocene geological changes and postglacial expansion during the Pleistocene were proposed in previous studies to account for the establishment of this geographical structure. In the present work, we have performed a spatial analysis of variation in shell morphometrics, after the partitioning of the overall variation into size and shape components by means of a principal component-based approach (Cadima and Jolliffe, 1996). In order to know if the same historical events have also structured shell variation, the analysis includes all the populations from North Africa which were investigated for anatomical and molecular surveys. Contrary to shell size, which shows a significant spatial heterogeneity essentially related to environmental pressures, variation in shell shape components splits the populations according to a geographical pattern reflective of hypotheses suggested for molecular markers and genital anatomy. This implies that the selective forces often invoked to explain spatial changes in shell shape are not the deciding factors in the present case. Moreover, within each of the two geographical clusters defined, Mantel correlograms show that the similarity between populations declines according to an isolation by distance model. Because of the different allometric relationships between shell size and genitalia measurements in Western and Eastern entities of North Africa, mechanical constraints, possibly leading to a precopulatory isolation in the contact zone, are involved. 相似文献
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Haenni M Saras E Bertin S Leblond P Madec JY Payot S 《Applied and environmental microbiology》2010,76(24):7957-7965
Bovine isolates of Streptococcus agalactiae (n = 76), Streptococcus dysgalactiae subsp. dysgalactiae (n = 32), and Streptococcus uberis (n = 101) were analyzed for the presence of different integrative and conjugative elements (ICEs) and their association with macrolide, lincosamide, and tetracycline resistance. The diversity of the isolates included in this study was demonstrated by multilocus sequence typing for S. agalactiae and pulsed-field gel electrophoresis for S. dysgalactiae and S. uberis. Most of the erythromycin-resistant strains carry an ermB gene. Five strains of S. uberis that are resistant to lincomycin but susceptible to erythromycin carry the lin(B) gene, and one has both linB and lnuD genes. In contrast to S. uberis, most of the S. agalactiae and S. dysgalactiae tetracycline-resistant isolates carry a tet(M) gene. A tet(S) gene was also detected in the three species. A Tn916-related element was detected in 30 to 50% of the tetracycline-resistant strains in the three species. Tetracycline resistance was successfully transferred by conjugation to an S. agalactiae strain. Most of the isolates carry an ICE integrated in the rplL gene. In addition, half of the S. agalactiae isolates have an ICE integrated in a tRNA lysine (tRNA(Lys)) gene. Such an element is also present in 20% of the isolates of S. dysgalactiae and S. uberis. A circular form of these ICEs was detected in all of the isolates tested, indicating that these genetic elements are mobile. These ICEs could thus also be a vehicle for horizontal gene transfer between streptococci of animal and/or human origin. 相似文献
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Immune defenses have been shown to be heavily involved in the evolution of physiological trade-offs. In this study, we compared the internal defense systems in two subspecies of the land snail Cornu aspersum that exhibit contrasting life-history strategies. The "fast-living" Cornu aspersum subsp. aspersa is widespread throughout the world, especially in ecosystems disturbed by man, whereas natural populations of the giant Cornu aspersum subsp. maxima, characterized by a longer life span, are present only in north Africa. Snails were experimentally challenged with Escherichia coli; the measurements used to assess their internal defense for cell- and humoral-mediated immune responses were bacterial clearance, hemocyte density, reactive oxygen species (ROS) production, and plasma antibacterial activity. Both subspecies showed a similar ability to clear bacteria from their hemolymph; however, they varied in the robustness of different individual immune components. Cornu aspersum aspersa had higher ROS activity than did C. a. maxima and lower plasma bactericidal activity. These results suggest that ecological factors can sculpt the immune response. One interpretation is that shorter life span selects for immune defenses such as ROS that, although effective, can cause long-term damage. Such different immune patterns obviously entail various costs involved in the strong intraspecific variation of life-history trade-offs we previously observed. We also have to consider that such variation might be related to intraspecific differences in the relative strength of resistance and tolerance mechanisms. 相似文献
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Madec Y Germanaud D Moya-Alvarez V Alkassoum W Issa A Amadou M Tchiombiano S Pizzocolo C Huber F Diallo S Abdoulaye-Mamadou R 《PloS one》2011,6(7):e22787
Background
In developing countries, malnutrition is a contributing factor in over 50% of child deaths. Mortality rates are higher in underweight children, and HIV-infection is known to increase underweight. Our goals were to evaluate the prevalence of HIV among children hospitalised for severe malnutrition (SM) at the Niamey national hospital (Niger), and to compare renutrition and mortality by HIV-status.Methods
Retrospective study based on all children <5 years hospitalised for SM between January 1st 2008 and July 1st 2009. HIV-prevalence was the ratio of HIV+ children on the number of children tested. Duration of renutrition and mortality were described using survival curves.Results
During the study period, 477 children were hospitalised for SM. HIV testing was accepted in 470 (98.5%), of which 40 were HIV+ (HIV prevalence (95% confidence interval) of 8.6% (6.2–11.5)). Duration of renutrition was longer in HIV+ than HIV− children (mean: 22 vs. 15 days; p = 0.003). During renutrition, 8 (20%) and 61 (14%) HIV+ and HIV− children died, respectively (p = 0.81).Conclusion
Around 9% of children hospitalised for severe malnutrition were HIV infected, while in Niger HIV prevalence in adults is estimated at 0.8%. This pleads for wider access to HIV testing in this population. 相似文献9.
Cladière L Hamze K Madec E Levdikov VM Wilkinson AJ Holland IB Séror SJ 《Molecular genetics and genomics : MGG》2006,275(4):409-420
YloQ, from Bacillus subtilis, was identified previously as an essential nucleotide-binding protein of unknown function. YloQ was successfully over-expressed
in Escherichia coli in soluble form. The purified protein displayed a low GTPase activity similar to that of other small bacterial GTPases such
as Bex/Era. Based on the demonstrated GTPase activity and the unusual order of the yloQ G motifs, we now designate this protein as CpgA (circularly permuted GTPase). An unexpected property of this low abundance
GTPase was the demonstration, using gel filtration and ultracentrifugation analysis, that the protein formed stable dimers,
dependent upon the concentration of YloQ(CpgA), but independent of GTP. In order to investigate function, cpgA was placed under the control of the pspac promotor in the B. subtilis chromosome. When grown in E or Spizizen medium in the absence of IPTG, the rate of growth was significantly reduced. A large
proportion of the cells exhibited a markedly perturbed morphology, with the formation of swollen, bent or ‘curly’ shapes.
To confirm that this was specifically due to depleted CpgA a plasmid-borne cpgA under pxyl control was introduced. This restored normal cell shape and growth rate, even in the absence of IPTG, provided xylose was
present. The crystal structure of CpgA(YloQ) suggests a role as a translation initiation factor and we discuss the possibility
that CpgA is involved in the translation of a subset of proteins, including some required for shape maintenance.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users. 相似文献
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Attig L Djiane J Gertler A Rampin O Larcher T Boukthir S Anton PM Madec JY Gourdou I Abdennebi-Najar L 《American journal of physiology. Endocrinology and metabolism》2008,295(5):E1117-E1125
Low birth weight resulting from intrauterine growth retardation (IUGR) is a risk factor for further development of metabolic diseases. The pig appears to reproduce nearly all of the phenotypic pathological consequences of human IUGR and is likely to be more relevant than rodents in studies of neonatal development. In the present work, we characterized the model of low-birth-weight piglets with particular attention to the hypothalamic leptin-sensitive system, and we tested whether postnatal leptin supplementation can reverse the precocious signs of adverse metabolic programming. Our results demonstrated that 1) IUGR piglets present altered postnatal growth and increased adiposity; 2) IUGR piglets exhibit abnormal hypothalamic distribution of leptin receptors that may be linked to further disturbance in food-intake behavior; and 3) postnatal leptin administration can partially reverse the IUGR phenotype by correcting growth rate, body composition, and development of several organs involved in metabolic regulation. We conclude that IUGR may be characterized by altered leptin receptor distribution within the hypothalamic structures involved in metabolic regulation and that leptin supplementation can partially reverse the IUGR phenotype. These results open interesting therapeutic perspectives in physiopathology for the correction of defects observed in IUGR. 相似文献