723 research outputs found
Genomic and molecular characterization of a novel quorum sensing molecule in Bacillus licheniformis
Quorum sensing molecules (QSMs) are involved in the regulation of complicated processes helping bacterial populations respond to changes in their cell-density. Although the QS gene cluster (comQXPA) has been identified in the genome sequence of some bacilli, the QS system B. licheniformis has not been investigated in detail, and its QSM (ComX pheromone) has not been identified. Given the importance of this antagonistic bacterium as an industrial workhorse, this study was aimed to elucidate B. licheniformis NCIMB-8874 QS. The results obtained from bioinformatics studies on the whole genome sequence of this strain confirmed the presence of essential quorum sensing-related genes. Although polymorphism was verified in three proteins of this cluster, ComQ, precursor-ComX and ComP, the transcription factor ComA was confirmed as the most conserved protein. The cell–cell communication of B. licheniformis NCIMB-8874 was investigated through further elucidation of the ComX pheromone as 13-amino acid peptide. The peptide sequence of the pheromone has been described through biochemical characterisation
Three-dimensional cephalometric evaluation of maxillary growth following in utero repair of cleft lip and alveolar-like defects in the mid-gestational sheep model
Objective: To evaluate maxillary growth following in utero repair of surgically created cleft lip and alveolar (CLA)-like defects by means of three-dimensional (3D) computer tomographic (CT) cephalometric analysis in the mid-gestational sheep model. Methods: In 12 sheep fetuses a unilateral CLA-like defect was created in utero (untreated control group: 4 fetuses). Four different bone grafts were used for the alveolar defect closure. After euthanasia, CT scans of the skulls of the fetuses, 3D re-constructions, and a 3D-CT cephalometric analysis were performed. Results: The comparisons between the operated and nonoperated skull sides as well as of the maxillary asymmetry among the experimental groups revealed no statistically significant differences of the 12 variables used. Conclusions: None of the surgical approaches used for the in utero correction of CLA-like defects seem to affect significantly postsurgical maxillary growth; however, when bone graft healing takes place, a tendency for almost normal maxillary growth can be observed. Copyright (c) 2006 S. Karger AG, Basel
Egg parasitoids of the genus Trichogramma (Hymenoptera, Trichogrammatidae) in olive groves of the Mediterranean region
A survey of egg parasitoids of the genus Trichogramma (Hymenoptera, Trichogrammatidae) was carried out in olive groves in Portugal,
Greece, Egypt, and Tunisia during the years 2002–2004. Parasitoids were obtained either by exposing sentinel eggs (Sitotroga
cerealella Olivier or Ephestia kuehniella Zeller) on olive trees or by collecting eggs of lepidopterous olive pests. Parasitized egg samples
were reared separately in the laboratory for emergence of parasitoids. These were further reared in separate lines and processed by morphological
and molecular biology techniques for species characterization. The recorded fauna of Trichogramma parasitoids in olive
groves was species poor and consisted of species mainly known from the Mediterranean region. Trichogramma bourarachae Pintureau
and Babault was found in Tunisia and Egypt, T. cordubensis Vargas and Cabello, and T. euproctidis Girault in Egypt, Trichogramma
cacoeciae Marchal in Portugal, Greece, Egypt, Tunisia and Trichogramma nerudai Pintureau and Gerding in Portugal. Apart from that,
Trichogramma oleae Voegele´ and Pointel was collected in Tunisia. This species is probably not indigenous, but has established after several
releases of a French strain were made in recent years. For selected strains, the sequence of the internal transcribed spacer 2 (ITS-2)
region of rDNA was determined and deposited in the GenBank database. Differences in important biological attributes were found
among collected strains of T. bourarachae, suggesting the existence of biotypes. The results contribute to the limited knowledge on distribution
and biodiversity of the genus Trichogramma in the Mediterranean region. They can be helpful for the preservation and use of
indigenous Trichogramma species in biological control of lepidopterous pests in olive and other local crops
MicroRNAs in pulmonary arterial remodeling
Pulmonary arterial remodeling is a presently irreversible pathologic hallmark of pulmonary arterial hypertension (PAH). This complex disease involves pathogenic dysregulation of all cell types within the small pulmonary arteries contributing to vascular remodeling leading to intimal lesions, resulting in elevated pulmonary vascular resistance and right heart dysfunction. Mutations within the bone morphogenetic protein receptor 2 gene, leading to dysregulated proliferation of pulmonary artery smooth muscle cells, have been identified as being responsible for heritable PAH. Indeed, the disease is characterized by excessive cellular proliferation and resistance to apoptosis of smooth muscle and endothelial cells. Significant gene dysregulation at the transcriptional and signaling level has been identified. MicroRNAs are small non-coding RNA molecules that negatively regulate gene expression and have the ability to target numerous genes, therefore potentially controlling a host of gene regulatory and signaling pathways. The major role of miRNAs in pulmonary arterial remodeling is still relatively unknown although research data is emerging apace. Modulation of miRNAs represents a possible therapeutic target for altering the remodeling phenotype in the pulmonary vasculature. This review will focus on the role of miRNAs in regulating smooth muscle and endothelial cell phenotypes and their influence on pulmonary remodeling in the setting of PAH
The emerging field of venom-microbiomics for exploring venom as a microenvironment, and the corresponding Initiative for Venom Associated Microbes and Parasites (iVAMP)
Venom is a known source of novel antimicrobial natural products. The substantial, increasing number of these discoveries have unintentionally culminated in the misconception that venom and venom-producing glands are largely sterile environments. Culture-dependent and -independent studies on the microbial communities in venom microenvironments reveal the presence of archaea, algae, bacteria, endoparasites, fungi, protozoa, and viruses. Venom-centric microbiome studies are relatively sparse to date and the adaptive advantages that venom-associated microbes might offer to their hosts, or that hosts might provide to venom-associated microbes, remain unknown. We highlight the potential for the discovery of venom-microbiomes within the adaptive landscape of venom systems. The considerable number of known, convergently evolved venomous animals juxtaposed with the comparatively few studies to identify microbial communities in venom provides new possibilities for both biodiversity and therapeutic discoveries. We present an evidence-based argument for integrating microbiology as part of venomics to which we refer to as venom-microbiomics. We also introduce iVAMP, the Initiative for Venom Associated Microbes and Parasites (https://ivamp-consortium.github.io/), as a growing consortium for interested parties to contribute and collaborate within this subdiscipline. Our consortium seeks to support diversity, inclusion and scientific collaboration among all researchers interested in this subdiscipline
Field-deployable, quantitative, rapid identification of active Ebola virus infection in unprocessed blood
The West African Ebola virus outbreak underlined the importance of delivering mass diagnostic capability outside the clinical or primary care setting in effectively containing public health emergencies caused by infectious disease. Yet, to date, there is no solution for reliably deploying at the point of need the gold standard diagnostic method, real time quantitative reverse transcription polymerase chain reaction (RT- qPCR), in a laboratory infrastructure-free manner. In this proof of principle work, we demonstrate direct performance of RT-qPCR on fresh blood using far-red fluorophores to resolve fluorogenic signal inhibition and controlled, rapid freeze/thawing to achieve viral genome extraction in a single reaction chamber assay. The resulting process is entirely free of manual or automated sample pre-processing, requires no microfluidics or magnetic/mechanical sample handling and thus utilizes low cost consumables. This enables a fast, laboratory infrastructure-free, minimal risk and simple standard operating procedure suited to frontline, field use. Developing this novel approach on recombinant bacteriophage and recombinant human immunodeficiency virus (HIV; Lentivirus), we demonstrate clinical utility in symptomatic EBOV patient screening using live, infectious Filoviruses and surrogate patient samples. Moreover, we evidence assay co-linearity independent of viral particle structure that may enable viral load quantification through pre-calibration, with no loss of specificity across an 8 log- linear maximum dynamic range. The resulting quantitative rapid identification (QuRapID) molecular diagnostic platform, openly accessible for assay development, meets the requirements of resource- limited countries and provides a fast response solution for mass public health screening against emerging biosecurity threats
Alzheimer's Disease: a Review of its Visual System Neuropathology. Optical Coherence Tomography-a Potential Role As a Study Tool in Vivo
Alzheimer's disease (AD) is a prevalent, long-term progressive degenerative disorder with great social impact. It is currently thought that, in addition to neurodegeneration, vascular changes also play a role in the pathophysiology of the disease. Visual symptoms are frequent and are an early clinical manifestation; a number of psychophysiologic changes occur in visual function, including visual field defects, abnormal contrast sensitivity, abnormalities in color vision, depth perception deficits, and motion detection abnormalities. These visual changes were initially believed to be solely due to neurodegeneration in the posterior visual pathway. However, evidence from pathology studies in both animal models of AD and humans has demonstrated that neurodegeneration also takes place in the anterior visual pathway, with involvement of the retinal ganglion cells' (RGCs) dendrites, somata, and axons in the optic nerve. These studies additionally showed that patients with AD have changes in retinal and choroidal microvasculature. Pathology findings have been corroborated in in-vivo assessment of the retina and optic nerve head (ONH), as well as the retinal and choroidal vasculature. Optical coherence tomography (OCT) in particular has shown great utility in the assessment of these changes, and it may become a useful tool for early detection and monitoring disease progression in AD. The authors make a review of the current understanding of retinal and choroidal pathological changes in patients with AD, with particular focus on in-vivo evidence of retinal and choroidal neurodegenerative and microvascular changes using OCT technology.info:eu-repo/semantics/publishedVersio
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