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111.
112.
Éric Armynot du Châtelet Viviane Bout-Roumazeilles Armelle Riboulleau Alain Trentesaux 《Revue de Micropaléontologie》2009,52(1):75
The paleoecological interpretation of fossil foraminiferal assemblages depends on an understanding of the ecological processes operating at the present. This study investigates both the quality of organic matter (OM) by elemental analysis as well as the sediment grain size and clay mineralogy to understand their relative influence on distribution and abundance of benthic foraminifera. This study is carried out on 15 samples regularly spaced from the mudflat to the tidal marsh. The results indicate that grain size is the most limiting parameter. Living (stained) benthic foraminiferal density and species richness are both very low within coarser sediments. OM is the second limiting factor. The density of foraminifera is the lowest and the species richness is the highest with the lowest organic carbon (Corg) contents and C/N < 12. Conversely, when the Corg is very high and C/N > 12, the density is high and the species richness medium. A high smectite proportion within the clay-size fraction seems to favor the development of Miliammina fusca. Trochammina inflata and Jadammina macrescens are both favored by an increase of organic carbon proportion but Trochammina inflata preferentially feeds on algal-derived OM when compared with Jadammina macrescens. 相似文献
113.
114.
Elo?se Raoust Viviane Balloy Ignacio Garcia-Verdugo Lhousseine Touqui Reuben Ramphal Michel Chignard 《PloS one》2009,4(10)
Background
The human lung is exposed to a large number of airborne pathogens as a result of the daily inhalation of 10,000 liters of air. Innate immunity is thus essential to defend the lungs against these pathogens. This defense is mediated in part through the recognition of specific microbial ligands by Toll-like receptors (TLR) of which there are at least 10 in humans. Pseudomonas aeruginosa is the main pathogen that infects the lungs of cystic fibrosis patients. Based on whole animal experiments, using TLR knockout mice, the control of this bacterium is believed to occur by the recognition of LPS and flagellin by TLRs 2,4 and 5, respectively.Methodology/Principal Findings
In the present study, we investigated in vitro the role of these same TLR and ligands, in alveolar macrophage (AM) and epithelial cell (EC) activation. Cellular responses to P. aeruginosa was evaluated by measuring KC, TNF-α, IL-6 and G-CSF secretion, four different markers of the innate immune response. AM and EC from WT and TLR2, 4, 5 and MyD88 knockout mice for were stimulated with the wild-type P. aeruginosa or with a mutant devoid of flagellin production.Conclusions/Significance
The results clearly demonstrate that only two ligand/receptor pairs are necessary for the induction of KC, TNF-α, and IL-6 synthesis by P. aeruginosa-activated cells, i.e. TLR2,4/LPS and TLR5/flagellin. Either ligand/receptor pair is sufficient to sense the bacterium and to trigger cell activation, and when both are missing lung EC and AM are unable to produce such a response as were cells from MyD88−/− mice. 相似文献115.
116.
Viviane Sternkopf Dorit Liebers-Helbig Markus S Ritz Jun Zhang Andreas J Helbig Peter de Knijff 《BMC evolutionary biology》2010,10(1):348
Background
Based on extensive mitochondrial DNA (mtDNA) sequence data, we previously showed that the model of speciation among species of herring gull (Larus argentatus) complex was not that of a ring species, but most likely due more complex speciation scenario's. We also found that two species, herring gull and glaucous gull (L. hyperboreus) displayed an unexpected biphyletic distribution of their mtDNA haplotypes. It was evident that mtDNA sequence data alone were far from sufficient to obtain a more accurate and detailed insight into the demographic processes that underlie speciation of this complex, and that extensive autosomal genetic analysis was warranted. 相似文献117.
Schemberger MO Bellafronte E Nogaroto V Almeida MC Schühli GS Artoni RF Moreira-Filho O Vicari MR 《Genetica》2011,139(11-12):1499-1508
Parodon and Apareiodon lack sufficiently consistent morphological traits to be considered a monophyletic group in Parodontidae. Species within this family are either sex-homomorphic or sex-heteromorphic (i.e., lacking a differentiated sex chromosome system, ZZ/ZW or ZZ/ZW(1)W(2)). In this study, a DNA fragment from the heterochromatin segment of the W chromosome of Apareiodon ibitiensis (named WAp) was microdissected and used for in situ mapping of nine Parodontidae species. The species were also characterized using a satellite DNA probe (pPh2004). The species were phylogenetically clustered according to 17 characters, which were examined by both classical and molecular cytogenetic techniques. Given the present results, the single ZZ/ZW sex chromosome system seems to have been derived from a paracentric inversion of a terminal WAp site onto the proximal regions of the short arms of a metacentric chromosome pair, followed by WAp site amplification. We reason that these events restrained recombination and favored differentiation of the W chromosome in some species. Moreover, co-hybridization experiments targeting the WAp and pPh2004 repetitive DNA sites of A. affinis suggest that the ZZ/ZW(1)W(2) sex chromosomes of this species may have arisen from a translocation between the proto-sex chromosome and an autosome. Our phylogenetic analysis corroborates the hypothesis of sex chromosome differentiation and establishes groups of closely related species. The phylogenetic reorganization in response to these new data supports the presence of internal monophyletic groups within Parodontidae. 相似文献
118.
Abreu PA da Silva VA Santos FC Castro HC Riscado CS de Souza MT Ribeiro CP Barbosa JE dos Santos CC Rodrigues CR Lione V Correa BA Cunha AC Ferreira VF de Souza MC Paixão IC 《Current microbiology》2011,62(5):1349-1354
Herpes simplex virus is an important human pathogen responsible for a range of diseases from mild uncomplicated mucocutaneous infections to life-threatening ones. Currently, the emergence of Herpes simplex virus resistant strains increased the need for more effective and less cytotoxic drugs for Herpes treatment. In this work, we synthesized a series of oxoquinoline derivatives and experimentally evaluated the antiviral activity against acyclovir resistant HSV-1 strain as well as their cytotoxity profile. The most active compound (3b), named here as Fluoroxaq-3b, showed a promising profile with a better cytotoxicity profile than acyclovir. The theoretical analysis of the structure-activity relationship of these compounds revealed some stereoelectronic properties such as lower LUMO energy and lipophilicity, besides a higher polar surface area and number of hydrogen bond acceptor groups as important parameters for the antiviral activity. Fluoroxaq-3b showed a good oral theoretical bioavailability, according to Lipinski rule of five, with a promising profile for further in vivo analysis. 相似文献
119.
Lakhdar Ghazouani Nesrine Abboud Sonia Ben Hadj Khalifa Claire Perret Viviane Nicaud Wassim Youssef Almawi François Cambien Touhami Mahjoub 《Molecular biology reports》2011,38(1):495-501
P-selectin (SELP) and its counter-receptor, P-selectin glycoprotein ligand-1 (PSGL-1), play key role in the transient attachment
of leukocytes to endothelial cells predisposing to coronary heart disease (CHD). In the current report, 293 angiographically
proven CHD patients and 327 age, gender, and race-matched controls were included. Our aim was to evaluate the contribution
to CHD of the following SNPs: C-2123G, G-1969A and T715P in SELP, Met62Ile and the VNTR variants in PSGL-1 gene in a North African population from Tunisia. While there were no significant differences in the distribution of SELP
or PSGL-1 alleles or genotypes between patients and controls, a trend for a significant association of the C-2123G genotypes
distribution with incident CHD was observed (P = 0.06). Assuming an additive model of transmission, the risk was 74% higher among subjects carrying the GG genotypes in
comparison to those carrying the CC genotype (OR = 1.74 [1.01–2.98], P = 0.04) and 80% higher in the recessive model (OR = 1.80 [1.08–3.01], P = 0.02). Haplotype analysis did not identify any specific SELP or PSGL-1 haplotypes to be associated with CHD. The present
study demonstrated no evidence of association between individual SELP or PSGL-1 SNPs or haplotypes with incident CHD. However,
this study replicates absence of association of the mostly studied SNP, T715P, previously reported in individuals with African
origin. 相似文献
120.
França K Villa RT Bastos VR Almeida AC Massucatti K Fukumaru D Bedin V 《Mycopathologia》2011,172(1):69-72
Subcutaneous chromoblastomycosis is an infection commonly seen in tropical and subtropical climates, usually caused by trauma
with vegetables and often affects the host’s lower limbs. We report a case of auricular chromoblastomycosis in a 67-year-old
man and discuss the rarity of this clinical manifestation of chromoblastomycosis in the medical literature. In the present
case, the etiologic agent was Fonsecaea pedrosoi, the most common agent found in Brazil. 相似文献