Ethnopharmacological Importance: Uncaria tomentosa Willd. DC., is used in the Amazonian region of South America, wherein ethnic groups use the plant to treat diseases, including gastric disorders.
View Article and Find Full Text PDFBoth non-Hermitian systems and the behavior of emitters coupled to structured baths have been studied intensely in recent years. Here, we study the interplay of these paradigmatic settings. In a series of examples, we show that a single quantum emitter coupled to a non-Hermitian bath displays a number of unconventional behaviors, many without Hermitian counterpart.
View Article and Find Full Text PDFA continuous intraocular delivery of neurotrophic factors (NFs) is being explored as a strategy to rescue photoreceptor cells and visual functions in degenerative retinal disorders that are currently untreatable. To establish a cell-based intraocular delivery system for a sustained administration of NFs to the dystrophic mouse retina, we used a polycistronic lentiviral vector to genetically modify adherently cultivated murine neural stem (NS) cells. The vector concurrently encoded a gene of interest, a reporter gene, and a resistance gene and thus facilitated the selection, cloning, and in vivo tracking of the modified cells.
View Article and Find Full Text PDFPurpose: To evaluate endothelial progenitor cell [late outgrowth endothelial progenitor cells (OECs)], vascular endothelial growth factor (VEGF), and stromal cell-derived factor 1α (SDF-1α) plasma levels as potential biomarkers before and during ranibizumab (Lucentis(®)) treatment for neovascular age-related macular degeneration (nvAMD).
Methods: Thirty-one patients with untreated nvAMD presenting for 3 consecutive intravitreal ranibizumab injections and a follow-up visit at 4 weeks intervals were enrolled. Peripheral blood was collected before each injection and at the follow-up visit and OEC clusters were cultured and evaluated according to previously published protocols.
Purpose: We recently demonstrated increased frequency and growth potential of late outgrowth endothelial progenitor cells (OECs) in patients with neovascular age-related macular degeneration (nvAMD). This study investigated the effects of short- and long-term in vitro inhibition of vascular endothelial growth factor (VEGF) Receptor-2 (VEGFR-2) signaling by SU5416 and other inhibitors of the VEGF signaling pathway in OECs.
Methods: OECs, from the peripheral blood of patients with nvAMD, and human umbilical vein endothelial cells were grown in the presence of SU5416, other VEGFR-2 tyrosine kinase inhibitors (TKIs), and inhibitors of phosphatidylinositol 3'-Kinase (PI3K)/protein kinase B (Akt) and protein kinase C (PKC) in complete angiogenic medium.
Comparative genomics is the cornerstone of identification of gene functions. The immense number of living organisms precludes experimental identification of functions except in a handful of model organisms. The bacterial domain is split into large branches, among which the Firmicutes occupy a considerable space.
View Article and Find Full Text PDFBacterial populations are subject to complex processes of diversification that involve mutation and horizontal DNA transfer mediated by transformation, transduction, or conjugation. Tracing the evolutionary events leading to genetic changes allows us to infer the history of a microbe. Here, we combine experimental and in silico approaches to explore the forces that drive the genome dynamics of Streptococcus agalactiae, the leading cause of neonatal infections.
View Article and Find Full Text PDFListeria monocytogenes is a food-borne, opportunistic, bacterial pathogen causing a wide spectrum of diseases, including meningitis, septicemia, abortion, and gastroenteritis, in humans and animals. Among the 13 L. monocytogenes serovars described, human listeriosis is mostly associated with strains of serovars 4b, 1/2b, and 1/2a.
View Article and Find Full Text PDFAdaptation to the host environment and exploitation of host cell functions are critical to the success of intracellular pathogens. Here, insight to these virulence mechanisms was obtained for the first time from the transcriptional program of the human pathogen Legionella pneumophila during infection of its natural host, Acanthamoeba castellanii. The biphasic life cycle of L.
View Article and Find Full Text PDFGroup B streptococcus (GBS) is a leading cause of neonatal morbidity and mortality. Multilocus sequence typing (MLST) revealed that the sequence type ST-17 defines a "highly virulent" serotype III clone strongly associated with neonatal invasive infections. Our aim was to identify a target sequence enabling rapid, simple, and specific detection of this clone by a real-time PCR assay.
View Article and Find Full Text PDFBackground: A chikungunya virus outbreak of unprecedented magnitude is currently ongoing in Indian Ocean territories. In Réunion Island, this alphavirus has already infected about one-third of the human population. The main clinical symptom of the disease is a painful and invalidating poly-arthralgia.
View Article and Find Full Text PDFStreptococcus agalactiae is a leading cause of invasive infections in neonates, and responsible for bovine mastitis. It is also a commensal bacterium adapted to asymptomatic colonization of the mammalian gut and of the genitourinary tract. Here, we report the analysis of a collection of 75 strains of human and animal origin by using serotyping, multilocus sequence typing, whole genome DNA-array hybridizations and sequence comparison of putatively virulence-associated loci.
View Article and Find Full Text PDFThe bacterium Photorhabdus establishes a highly specific association with Heterorhabditis, its nematode host. Photorhabdus strains associated with Heterorhabditis bacteriophora or Heterorhabditis megidis were compared using a Photorhabdus DNA microarray. We describe 31 regions belonging to the Photorhabdus flexible gene pool.
View Article and Find Full Text PDFStreptococcus agalactiae (group B streptococcus [GBS]) is the leading cause of neonatal pneumonia, sepsis, and meningitis. An in silico genome analysis indicated that GBS strain NEM316 encodes 35 proteins containing an LPXTG motif which are thought to be covalently linked to the peptidoglycan by an enzyme called sortase. The role of these cell wall-anchored proteins in GBS pathogenesis was evaluated on a global level by inactivating the srtA gene.
View Article and Find Full Text PDFPhotorhabdus is an entomopathogenic bacterium belonging to the Enterobacteriaceae. The genome of the TT01 strain of Photorhabdus luminescens was recently sequenced and a large number of toxin-encoding genes were found. Genomic analysis predicted the presence on the chromosome of genes encoding a type three secretion system (TTSS), the main role of which is the delivery of effector proteins directly into eukaryotic host cells.
View Article and Find Full Text PDFIn this study, we carried out a detailed structural and functional analysis of a Streptococcus agalactiae (GBS) two-component system which is orthologous to the CovS/CovR (CsrS/CsrR) regulatory system of Streptococcus pyogenes. In GBS, covR and covS are part of a seven gene operon transcribed from two promoters that are not regulated by CovR. A DeltacovSR mutant was found to display dramatic phenotypic changes such as increased haemolytic activity and reduced CAMP activity on blood agar.
View Article and Find Full Text PDFLegionella pneumophila, the causative agent of Legionnaires' disease, replicates as an intracellular parasite of amoebae and persists in the environment as a free-living microbe. Here we have analyzed the complete genome sequences of L. pneumophila Paris (3,503,610 bp, 3,077 genes), an endemic strain that is predominant in France, and Lens (3,345,687 bp, 2,932 genes), an epidemic strain responsible for a major outbreak of disease in France.
View Article and Find Full Text PDFEntomopathogenic bacteria of the genus Photorhabdus harbor a type III secretion system. This system was probably acquired prior to the separation of the species within this genus. Furthermore, the core components of the secretion machinery are highly conserved but the predicted effectors differ between Photorhabdus luminescens and P.
View Article and Find Full Text PDFPhotorhabdus luminescens is an insect-pathogenic bacterium that forms a symbiosis with specific entomopathogenic nematodes. In this bacterium, a symbiosis-'deficient' phenotypic variant (known as the secondary variant or form II) arises at a low frequency during prolonged incubation. A knock-out mutant was generated of the regulator of a newly identified two-component regulatory system, designated AstR-AstS.
View Article and Find Full Text PDFAnalysis of the Photorhabdus luminescens genome sequence revealed that the pts region is related to the tail synthesis gene core of the P2 phage. The pts locus encodes a DNA invertase homologue. PCR-RFLP analysis showed the two potential tail fiber regions of the pts locus present DNA inversions.
View Article and Find Full Text PDFPhotorhabdus luminescens is a symbiont of entomopathogenic nematodes. Analysis of the genome sequence of this organism revealed a homologue of PhoP-PhoQ, a two-component system associated with virulence in intracellular bacterial pathogens. This organism was shown to respond to the availability of environmental magnesium.
View Article and Find Full Text PDFMotivation: Contigs-Assembly and Annotation Tool-Box (CAAT-Box) is a software package developed for the computational part of a genome project where the sequence is obtained by a shotgun strategy. CAAT-Box contains new tools to predict links between contigs by using similarity searches with other whole genome sequences. Most importantly, it allows annotation of a genome to commence during the finishing phase using a gene-oriented strategy.
View Article and Find Full Text PDFListeria monocytogenes is a food-borne bacterial pathogen that causes a wide spectrum of diseases, such as meningitis, septicemia, abortion, and gastroenteritis, in humans and animals. Among the 13 L. monocytogenes serovars described, invasive disease is mostly associated with serovar 4b strains.
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