CNS activity of Pokeweed Anti-viral Protein (PAP) in mice infected with Lymphocytic Choriomeningitis Virus (LCMV)

BACKGROUND: Others and we have previously described the potent in vivo and in vitro activity of the broad-spectrum antiviral agent PAP (Pokeweed antiviral protein) against a wide range of viruses. The purpose of the present study was to further elucidate the anti-viral spectrum of PAP by examining its effects on the survival of mice challenged with lymphocytic choriomeningitis virus (LCMV). METHODS: We examined the therapeutic effect of PAP in CBA mice inoculated with intracerebral injections of the WE54 strain of LCMV at a 1000 PFU dose level that is lethal to 100% of mice within 7–9 days. Mice were treated either with vehicle or PAP administered intraperitoneally 24 hours prior to, 1 hour prior to and 24 hours, 48 hours 72 hours and 96 hours after virus inoculation. RESULTS: PAP exhibits significant in vivo anti- LCMV activity in mice challenged intracerebrally with an otherwise invariably fatal dose of LCMV. At non-toxic dose levels, PAP significantly prolonged survival in the absence of the majority of disease-associated symptoms. The median survival time of PAP-treated mice was >21 days as opposed to 7 days median survival for the control (p = 0.0069). CONCLUSION: Our results presented herein provide unprecedented experimental evidence that PAP exhibits antiviral activity in the CNS of LCMV-infected mice

Genetic relatedness and molecular characterization of multidrug resistant Acinetobacter baumannii isolated in central Ohio, USA

<p>Abstract</p> <p>Background</p> <p>Over the last decade, nosocomial infections due to <it>Acinetobacter baumannii </it>have been described with an increasing trend towards multidrug resistance, mostly in intensive care units. The aim of the present study was to determine the clonal relatedness of clinical isolates and to elucidate the genetic basis of imipenem resistance.</p> <p>Methods</p> <p><it>A. baumannii </it>isolates (n = 83) originated from two hospital settings in central Ohio were used in this study. Pulsed-field gel electrophoresis genotyping and antimicrobial susceptibility testing for clinically relevant antimicrobials were performed. Resistance determinants were characterized by using different phenotypic (accumulation assay for efflux) and genotypic (PCR, DNA sequencing, plasmid analysis and electroporation) approaches.</p> <p>Results</p> <p>The isolates were predominantly multidrug resistant (>79.5%) and comprised of thirteen unique pulsotypes, with genotype VII circulating in both hospitals. The presence of <it>bla</it>_OXA-23in 13% (11/83) and IS_{<it>Aba1 </it>}linked <it>bla</it>_OXA-66in 79.5% (66/83) of clinical isolates was associated with high level imipenem resistance. In this set of OXA producing isolates, multidrug resistance was bestowed by <it>bla</it>_ADC-25, class 1 integron-borne aminoglycoside modifying enzymes, presence of sense mutations in <it>gyrA</it>/<it>parC </it>and involvement of active efflux (with evidence for the presence of <it>adeB </it>efflux gene).</p> <p>Conclusion</p> <p>This study underscores the major role of carbapenem-hydrolyzing class D β-lactamases, and in particular the acquired OXA-23, in the dissemination of imipenem-resistant <it>A. baumannii</it>. The co-occurrence of additional resistance determinant could also be a significant threat.</p

Time-Series Photometry of M67: W UMa Systems, Blue Stragglers, and Related Systems

We present an analysis of over 2200 V images taken on 14 nights at the Mt. Laguna 1 m telescope of the open cluster M67. Our observations overlap but extend beyond the field analyzed by Gilliland et al. (1991), and complement data recently published by van den Berg et al. (2002) and Stassun et al. (2002). We show variability in the light curves of all 4 of the known W UMa variables on timescales ranging from a day to decades (for AH Cnc). We have modeled the light curve of AH Cnc, and the total eclipses allow us to determine q = 0.16 +0.03/-0.02 and i = 86 +4/-8 degrees. The position of this system near the turnoff of M67 makes it useful for constraining the turnoff mass for the cluster. We have also detected two unusual features in the light curve of AH Cnc that may be caused by prominences. We have also monitored cluster blue stragglers for variability, and we present evidence hinting at low level variations in the stragglers S752, S968, and S1263, and we place limits on the variability of a number of other cluster blue stragglers. Finally, we provide photometry of the sub-subgiant branch star S1063 showing variability on timescales similar to the orbital period, while the ``red straggler'' S1040 shows evidence of an unexplained drop in brightness at phases corresponding to the passage of the white dwarf in front of the giant.Comment: 44 pages, 16 figures, AASTeX, accepted for A

Sub-Subgiants in the Old Open Cluster M67?

We report the discovery of two spectroscopic binaries in the field of the old open cluster M67 -- S1063 and S1113 -- whose positions in the color-magnitude diagram place them approximately 1 mag below the subgiant branch. A ROSAT study of M67 independently discovered these stars to be X-ray sources. Both have proper-motion membership probabilities greater than 97%; precise center-of-mass velocities are consistent with the cluster mean radial velocity. S1063 is also projected within one core radius of the cluster center. S1063 is a single-lined binary with a period of 18.396 days and an orbital eccentricity of 0.206. S1113 is a double-lined system with a circular orbit having a period of 2.823094 days. The primary stars of both binaries are subgiants. The secondary of S1113 is likely a 0.9 Mo main-sequence star, which implies a 1.3 Mo primary star. We have been unable to explain securely the low apparent luminosities of the primary stars; neither binary contain stars presently limited in radius by their Roche lobes. We speculate that S1063 and S1113 may be the products of close stellar encounters involving binaries in the cluster environment, and may define alternative stellar evolutionary tracks associated with mass-transfer episodes, mergers, and/or dynamical stellar exchanges

In vitro template-change PCR to create single crossover libraries: a case study with B. thuringiensis Cry2A toxins

During evolution the creation of single crossover chimeras between duplicated paralogous genes is a known process for increasing diversity. Comparing the properties of homologously recombined chimeras with one or two crossovers is also an efficient strategy for analyzing relationships between sequence variation and function. However, no well-developed in vitro method has been established to create single-crossover libraries. Here we present an in vitro template-change polymerase change reaction that has been developed to enable the production of such libraries. We applied the method to two closely related toxin genes from B. thuringiensis and created chimeras with differing properties that can help us understand how these toxins are able to differentiate between insect species

Diets containing sea cucumber (Isostichopus badionotus) meals are hypocholesterolemic in young rats

Peer reviewedPublisher PD

The KNee OsteoArthritis Prediction (KNOAP2020) challenge:An image analysis challenge to predict incident symptomatic radiographic knee osteoarthritis from MRI and X-ray images

Objectives: The KNee OsteoArthritis Prediction (KNOAP2020) challenge was organized to objectively compare methods for the prediction of incident symptomatic radiographic knee osteoarthritis within 78 months on a test set with blinded ground truth. Design: The challenge participants were free to use any available data sources to train their models. A test set of 423 knees from the Prevention of Knee Osteoarthritis in Overweight Females (PROOF) study consisting of magnetic resonance imaging (MRI) and X-ray image data along with clinical risk factors at baseline was made available to all challenge participants. The ground truth outcomes, i.e., which knees developed incident symptomatic radiographic knee osteoarthritis (according to the combined ACR criteria) within 78 months, were not provided to the participants. To assess the performance of the submitted models, we used the area under the receiver operating characteristic curve (ROCAUC) and balanced accuracy (BACC). Results: Seven teams submitted 23 entries in total. A majority of the algorithms were trained on data from the Osteoarthritis Initiative. The model with the highest ROCAUC (0.64 (95% confidence interval (CI): 0.57–0.70)) used deep learning to extract information from X-ray images combined with clinical variables. The model with the highest BACC (0.59 (95% CI: 0.52–0.65)) ensembled three different models that used automatically extracted X-ray and MRI features along with clinical variables. Conclusion: The KNOAP2020 challenge established a benchmark for predicting incident symptomatic radiographic knee osteoarthritis. Accurate prediction of incident symptomatic radiographic knee osteoarthritis is a complex and still unsolved problem requiring additional investigation.</p

Dominant Negative Mutants of Bacillus thuringiensis Cry1Ab Toxin Function as Anti-Toxins: Demonstration of the Role of Oligomerization in Toxicity

BACKGROUND:Bacillus thuringiensis Cry toxins, that are used worldwide in insect control, kill insects by a mechanism that depends on their ability to form oligomeric pores that insert into the insect-midgut cells. These toxins are being used worldwide in transgenic plants or spray to control insect pests in agriculture. However, a major concern has been the possible effects of these insecticidal proteins on non-target organisms mainly in ecosystems adjacent to agricultural fields. METHODOLOGY/PRINCIPAL FINDINGS:We isolated and characterized 11 non-toxic mutants of Cry1Ab toxin affected in different steps of the mechanism of action namely binding to receptors, oligomerization and pore-formation. These mutant toxins were analyzed for their capacity to block wild type toxin activity, presenting a dominant negative phenotype. The dominant negative phenotype was analyzed at two levels, in vivo by toxicity bioassays against susceptible Manduca sexta larvae and in vitro by pore formation activity in black lipid bilayers. We demonstrate that some mutations located in helix alpha-4 completely block the wild type toxin activity at sub-stoichiometric level confirming a dominant negative phenotype, thereby functioning as potent antitoxins. CONCLUSIONS/SIGNIFICANCE:This is the first reported case of a Cry toxin dominant inhibitor. These data demonstrate that oligomerization is a fundamental step in Cry toxin action and represent a potential mechanism to protect special ecosystems from the possible effect of Cry toxins on non-target organisms