Rapid Polymerase Chain Reaction–Based Test for the Detection of Female Urogenital Chlamydial Infections

Objective: The purpose of this study was to evaluate the Amplicor Chlamydia trachomatis Test (Roche Molecular Systems, Branchburg, NJ), a polymerase chain reaction (PCR)-based technique, as a screening test for the detection of female urogenital C. trachomatis infections, comparing it to an enzyme immunoassay method

Biogeographic analysis of the Tortugas Ecological Reserve: Examining the refuge effect following reserve establishment

Almost 120 days at sea aboard three NOAA research vessels and one fishing vessel over the past three years have supported biogeographic characterization of Tortugas Ecological Reserve (TER). This work initiated measurement of post-implementation effects of TER as a refuge for exploited species. In Tortugas South, seafloor transect surveys were conducted using divers, towed operated vehicles (TOV), remotely operated vehicles (ROV), various sonar platforms, and the Deepworker manned submersible. ARGOS drifter releases, satellite imagery, ichthyoplankton surveys, sea surface temperature, and diver census were combined to elucidate potential dispersal of fish spawning in this environment. Surveys are being compiled into a GIS to allow resource managers to gauge benthic resource status and distribution. Drifter studies have determined that within the ~ 30 days of larval life stage for fishes spawning at Tortugas South, larvae could reach as far downstream as Tampa Bay on the west Florida coast and Cape Canaveral on the east coast. Together with actual fish surveys and water mass delineation, this work demonstrates that the refuge status of this area endows it with tremendous downstream spillover and larval export potential for Florida reef habitats and promotes the maintenance of their fish communities. In Tortugas North, 30 randomly selected, permanent stations were established. Five stations were assigned to each of the following six areas: within Dry Tortugas National Park, falling north of the prevailing currents (Park North); within Dry Tortugas National Park, falling south of the prevailing currents (Park South); within the Ecological Reserve falling north of the prevailing currents (Reserve North); within the Ecological Reserve falling south of the prevailing currents (Reserve South); within areas immediately adjacent to these two strata, falling north of the prevailing currents (Out North); and within areas immediately adjacent to these two strata, falling south of the prevailing currents (Out South). Intensive characterization of these sites was conducted using multiple sonar techniques, TOV, ROV, diver-based digital video collection, diver-based fish census, towed fish capture, sediment particle-size, benthic chlorophyll analyses, and stable isotope analyses of primary producers, fish, and, shellfish. In order to complement and extend information from studies focused on the coral reef, we have targeted the ecotone between the reef and adjacent, non-reef habitats as these areas are well-known in ecology for indicating changes in trophic relationships at the ecosystem scale. Such trophic changes are hypothesized to occur as top-down control of the system grows with protection of piscivorous fishes. Preliminary isotope data, in conjunction with our prior results from the west Florida shelf, suggest that the shallow water benthic habitats surrounding the coral reefs of TER will prove to be the source of a significant amount of the primary production ultimately fueling fish production throughout TER and downstream throughout the range of larval fish dispersal. Therefore, the status and influence of the previously neglected, non-reef habitat within the refuge (comprising ~70% of TER) appears to be intimately tied to the health of the coral reef community proper. These data, collected in a biogeographic context, employing an integrated Before-After Control Impact design at multiple spatial scales, leave us poised to document and quantify the postimplementation effects of TER. Combined with the work at Tortugas South, this project represents a multi-disciplinary effort of sometimes disparate disciplines (fishery oceanography, benthic ecology, food web analysis, remote sensing/geography/landscape ecology, and resource management) and approaches (physical, biological, ecological). We expect the continuation of this effort to yield critical information for the management of TER and the evaluation of protected areas as a refuge for exploited species. (PDF contains 32 pages.

Accumulation of Hexavalent Uranium by Highly Organic Soils at the Needle's Eye Natural Analogue Site, South West Scotland

Nuclear power has the potential to provide electricity with lower emissions of greenhouse gases than electricity generated by combustion of fossil fuels. However, a downside of nuclear power generation is the production of waste products which will be radioactive for long timescales into the future. Safe storage of generated waste is a significant consideration for the future use of nuclear power. Studies have been undertaken at the Needle's Eye Natural Analogue site in Southwest Scotland to evaluate if the highly organic soils (loss on ignition ~ 80%) at the site are an effective barrier for uranium (U), a major component of nuclear waste. Analysis of soils by x-ray absorption spectroscopy (XAS) demonstrated that, despite the dominant waterlogged and anaerobic conditions in the soil at the site, conducive to the reduction of U to U(IV), the majority of U in the upper 30 cm of the soil profile was present as U(VI) complexed with oxygen functional groups of soil organic matter (SOM). Results of SOM characterization (UV/Vis spectroscopy, FTIR and ¹H NMR) demonstrated that SOM in the region of the soil profile with greatest U accumulation was relatively enriched with carboxylate functional groups and fulvic acid organic matter compared to deeper in the soil profile where aromatic structures and humic acids became more prominent. The results indicate that highly organic soils can be an effective barrier to the mobility of U in the surface environment, with implications for the future selection of sites for long-term storage of nuclear waste

De novo Vessel Formation Through Cross-Talk of Blood-Derived Cells and Mesenchymal Stromal Cells in the Absence of Pre-existing Vascular Structures

Background: The generation of functional blood vessels remains a key challenge for regenerative medicine. Optimized in vitro culture set-ups mimicking the in vivo perivascular niche environment during tissue repair may provide information about the biological function and contribution of progenitor cells to postnatal vasculogenesis, thereby enhancing their therapeutic potential. Aim: We established a fibrin-based xeno-free human 3D in vitro vascular niche model to study the interaction of mesenchymal stromal cells (MSC) with peripheral blood mononuclear cells (PBMC) including circulating progenitor cells in the absence of endothelial cells (EC), and to investigate the contribution of this cross-talk to neo-vessel formation. Materials and Methods: Bone marrow-derived MSC were co-cultured with whole PBMC, enriched monocytes (Mo), enriched T cells, and Mo together with T cells, respectively, obtained from leukocyte reduction chambers generated during the process of single-donor platelet apheresis. Cells were embedded in 3D fibrin matrices, using exclusively human-derived culture components without external growth factors. Cytokine secretion was analyzed in supernatants of 3D cultures by cytokine array, vascular endothelial growth factor (VEGF) secretion was quantified by ELISA. Cellular and structural re-arrangements were characterized by immunofluorescence and confocal laser-scanning microscopy of topographically intact 3D fibrin gels. Results: 3D co-cultures of MSC with PBMC, and enriched Mo together with enriched T cells, respectively, generated, within 2 weeks, complex CD31C /CD34C vascular structures, surrounded by basement membrane collagen type-IVC cells and matrix, in association with increased VEGF secretion. PBMC contained CD31C CD34CCD45dimCD14 progenitor-type cells, and EC of neo-vessels were PBMC-derived. Vascular structures showed intraluminal CD45C cells that underwent apoptosis thereby creating a lumen. Cross-talk of MSC with enriched Mo provided a proangiogenic paracrine environment. MSC co-cultured with enriched T cells formed "cellin-cell" structures generated through internalization of T cells by CD31C CD45dim = cells. No vascular structures were detected in co-cultures of MSC with either Mo or T cells. Conclusion: Our xeno-free 3D in vitro vascular niche model demonstrates that a complex synergistic network of cellular, extracellular and paracrine cross-talk can contribute to de novo vascular development through self-organization via co-operation of immune cells with blood-derived progenitor cells and MSC, and thereby may open a new perspective for advanced vascular tissue engineering in regenerative medicine

The Binding of Factor H to a Complex of Physiological Polyanions and C3b on Cells Is Impaired in Atypical Hemolytic Uremic Syndrome

Factor H (fH) is essential for complement homeostasis in fluid-phase and on surfaces. Its two C-terminal domains (CCP 19-20) anchor fH to self surfaces where it prevents C3b amplification in a process requiring its N-terminal four domains. In atypical hemolytic uremic syndrome (aHUS), mutations clustering towards the C-terminus of fH may disrupt interactions with surface-associated C3b or polyanions and thereby diminish the ability of fH to regulate complement. To test this we compared a recombinant protein encompassing CCP 19-20 with sixteen mutants. The mutations had only very limited and localized effects on protein structure. While we found four aHUS-linked fH mutations that decreased binding to C3b and/or to heparin (a model compound for cell-surface polyanionic carbohydrates), we identified five aHUS-associated mutants with increased affinity for either or both ligands. Strikingly, these variable affinities for the individual ligands did not correlate with the extent to which all the aHUS-associated mutants were found to be impaired in a more physiological assay that measured their ability to inhibit cell surface complement functions of full-length fH. Taken together, our data suggest that disruption of a complex fH-self surface recognition process, involving a balance of affinities for protein and physiological carbohydrate ligands, predisposes to aHUS

OPTIMADE, an API for exchanging materials data.

The Open Databases Integration for Materials Design (OPTIMADE) consortium has designed a universal application programming interface (API) to make materials databases accessible and interoperable. We outline the first stable release of the specification, v1.0, which is already supported by many leading databases and several software packages. We illustrate the advantages of the OPTIMADE API through worked examples on each of the public materials databases that support the full API specification

Investigations of peptide structural stability in vacuo

Gas-phase analytical techniques provide very valuable tools for tackling the structural complexity of macromolecular structures such as those encountered in biological systems. Conformational dynamics of polypeptides and polypeptide assemblies underlie most biological functionalities, yet great difficulties arise when investigating such phenomena with the well-established techniques of X-ray crystallography and NMR. In areas such as these ion mobility interfaced with mass spectrometry (IMMS) and molecular modelling can make a significant contribution. During an IMMS experiment analyte ions drift in a chamber filled with an inert gas; measurement of the transport properties of analyte ions under the influence of a weak electric field can lead to determination of the orientationally-averaged collision cross-section of all resolved ionic species. A comparison with cross-sections estimated for model molecular geometries can lead to structural assignments. Thus IMMS can be used effectively to separate gas-phase ions based on their conformation. The drift tube employed in the experiments described herein is thermally regulated, which also enables the determination of collision cross-sections over a range of temperatures, and can provide a view of temperature-dependent conformational dynamics over the experimental (low microsecond) timescale. Studies described herein employ IMMS and a gamut of other MS-based techniques, solution spectroscopy and – importantly – molecular mechanics simulations to assess a) conformational stability of isolated peptide ions, with a focus on small model peptides and proteins, especially the Trp cage miniprotein; and b) structural characteristics of oligomeric aggregates of an amyloidogenic peptide. The results obtained serve to clarify the factors which dominate the intrinsic stability of non-covalent structure in isolated peptides and peptide assemblies. Strong electrostatic interactions are found to play a pivotal role in determining the conformations of isolated proteins. Secondary structures held together by hydrogen bonding, such as helices, are stable in the absence of solvent, however gas-phase protein structures display loss of their hydrophobic cores. The absence of a polar solvent, “self-solvation” is by far the most potent force influencing the gas-phase configuration of these systems. Geometries that are more compact than the folded state observed in solution are routinely detected, indicating the existence of intrinsically stable compact non-native states in globular proteins, illuminating the nature of proteins’ ‘unfolded’ states.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Título en español.

Biological control methods for schistosomiasis in man and fascioliasis in cattle include the use of Marisa cornuarietis, a predatory snail. To insure that this snail does not transmit the trematode parasites, laboratory exposures were made under favorable conditions. It was found that Marisa cornuarietis, as well as other potential biological control snails, did not transmit either of the two parasites.Resumen en español