578 research outputs found

    Characterization of endospore-forming bacteria associated with entomopathogenic nematodes, Heterorhabditis spp., and description of Paenibacillus nematophilus sp. nov.

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    Endospore-forming bacteria were isolated from insect-pathogenic nematodes, Heterorhabditis spp., from three diverse geographical locations. Spindle-shaped sporangia of these bacteria adhere to the free-living infective stage of the nematode, which carries them to new insect hosts, where the bacterium reproduces. These isolates were characterized based on phenotypic and chemotaxonomic properties and 16S rRNA gene sequences. Analysis of the 16S rRNA gene placed the isolates within the genus Paenibacillus. The isolates shared higher sequence similarities with each other (95.1-100%) than they did with any other named species within the genus (89.2-94%). Paenibacillus macquariensis, Paenibacillus azoreducens, Paenibacillus amylolyticus and Paenibacillus durus were among the species with highest sequence similarity to these isolates. The isolates shared a high degree of phenotypic similarity and were easily distinguished from closely related members of the genus. Anteiso-C15:0 and C16:0 were among the major fatty acid types and the DNA G + C content was approximately 44 mol% in all isolates. DNA-DNA similarity studies revealed genomic heterogeneity among the isolates, such that they are likely to represent more than one species. Two of the isolates (both from a Heterorhabditis megidis isolate from Estonia) are phenotypically distinguishable from the others and are proposed as a single species, Paenibacillus nematophilus sp. nov. The type strain for this novel species is NEM1aT (=DSM 13559T =NCIMB 13845T). The other isolates, although closely related to the proposed species, are likely to represent at least one, but most likely two, novel species

    Acute B-Cell Inhibition by Soluble Antigen Arrays Is Valency-Dependent and Predicts Immunomodulation in Splenocytes

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Biomacromolecules, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.biomac.9b00328.Antigen valency plays a fundamental role in directing the nature of an immune response to be stimulatory or tolerogenic. Soluble Antigen Arrays (SAgAs) are an antigen-specific immunotherapy that combats autoimmunity through the multivalent display of autoantigen. While mechanistic studies have shown SAgAs to induce T and B-cell anergy, the effect of SAgA valency has never been experimentally tested. Here, SAgAs of discrete antigen valencies were synthesized by click chemistry and evaluated for acute B-cell signaling inhibition as well as downstream immunomodulatory effects in splenocytes. Initial studies using the Raji B-cell line demonstrated SAgA valency dictated the extent of calcium flux. Lower valency constructs elicited the largest reductions in B-cell activation. In splenocytes from mice with experimental autoimmune encephalomyelitis, the same valency-dependent effects were evident in the downregulation of the costimulatory marker CD86. The reduction of calcium flux observed in Raji B-cells correlated strongly with downregulation in splenocyte CD86 expression after 72 hours. Here, a thorough analysis of SAgA antigenic valency illustrates that low, but not monovalent, presentation of autoantigen was ideal for eliciting the most potent immunomodulatory effects.Madison and Lila Self Graduate Fellowship at the University of KansasNIH T32 GM00854

    Specific Adherence of Sporangia of a Paenibacillus Sp. Bacterium to Heterorhabditis Spp. Nematodes. Hitching a Ride to Lunch?

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    The fact that entomopathogenic nematodes of the genera Heterorhabditis and Stemernema are normally found in mutuahstic association with the bacteria Photorhabdus spp. and Xenorhabdus spp , respectively, has long been universally accepted However, the extent and nature of their interaction with bacteria other than these, under natural conditions, is less well known. There have been a number of reports of other bacteria being isolated from entomopathogenic nematodes, particularly from Stemernema spp. (reviewed by Boemare et al, 1998a). Jackson et al (1995) reported the occurrence oí Providencia rettgeri with a number of strains of Heterorhabditis spp. originating from different geographical regions. Boemare et al (1998b) point out that écologiste will tend to harvest nematodes resulting from "successful" parasitisms, i e. those where the cadaver is not more rapidly putrefied by the presence of co-associated bacteria other that the natural symbiont. With this in mind it is conceivable that we may under-estimate the frequency of association of these nematodes with other bacteria

    Triticale: a general overview of its use in poultry production

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    Triticale, a hybrid of wheat and rye, is one of the most promising grain crops. In terms of productivity, the level of metabolizable energy, and the composition of essential amino acids, triticale surpasses rye and is not inferior to wheat. It is resistant to the most dangerous diseases and pests. In terms of nutritional value, triticale can compete with wheat, corn, sorghum, and barley. The presence, however, of antinutrients in triticale such as non-starch polysaccharides, alkylresorcinols, and trypsin inhibitors significantly reduces the biological value of this crop. In the global practice of compound feed production, there are many methods and technologies for processing grain raw materials to increase their nutritional value. Enzymatic treatment and extrusion technologies are worthy of special attention. The high content of triticale in the compound feed of poultry breeder flocks should be used effectively, taking into account the characteristics of triticale varieties and climatic conditions. An optimal triticale level in feed (15% for layer and broiler chicks) may improve body weight gain and reduce feed costs when raising replacement young stock. Layer breeder flocks fed a 20% triticale-based diet may have increased egg production, high viability, and flock uniformity. Producing triticale-soy and triticale-sunflower extrudates and supplementing the diet of poultry flocks with essential amino acids represent promising avenues for maximizing the benefits of triticale. Innovative methods of achieving this goal should be further developed and put into practice, particularly given the expansion of triticale's cultivation areas

    Triticale: a general overview of its use in poultry production

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    Subjects: Agriculture, Dairy & Animal Science. Contributors: Olena V. Gaviley, Oleg O. Katerynych, Igor A. Ionov, Olena O. Dekhtiarova, Darren K. Griffin, Michael N. Romanov. Triticale, a hybrid of wheat and rye, is one of the most promising grain crops. In terms of productivity, the level of metabolizable energy, and the composition of essential amino acids, triticale surpasses rye and is not inferior to wheat. It is resistant to the most dangerous diseases and pests. In terms of nutritional value, triticale can compete with wheat, corn, sorghum, and barley. The presence, however, of antinutrients in triticale such as non-starch polysaccharides, alkylresorcinols, and trypsin inhibitors significantly reduces the biological value of this crop. In the global practice of compound feed production, there are many methods and technologies for processing grain raw materials to increase their nutritional value. Enzymatic treatment and extrusion technologies are worthy of special attention. The high content of triticale in the compound feed of poultry breeder flocks should be used effectively, taking into account the characteristics of triticale varieties and climatic conditions. An optimal triticale level in feed (15% for layer and broiler chicks) may improve body weight gain and reduce feed costs when raising replacement young stock. Layer breeder flocks fed a 20% triticale-based diet may have increased egg production, high viability, and flock uniformity. Producing triticale-soy and triticale-sunflower extrudates and supplementing the diet of poultry flocks with essential amino acids represent promising avenues for maximizing the benefits of triticale. Innovative methods of achieving this goal should be further developed and put into practice, particularly given the expansion of triticale's cultivation areas. Poultry producers consistently face the challenges of increasing flock productivity and reducing production costs. Additional issues to be kept in mind include disease control (with a minimum use of antibiotics) for both animals and food crops, animal welfare, and environmental concerns. Balanced feeding plays one of the most crucial roles in poultry production. It needs to meet all the needs of the bird in accordance with age and productivity, providing a diet consisting of the required content of basic nutrients, energy, and biologically active substances including, proteins, amino acids, and carbohydrates. Moreover, in order to expand the fodder base in the worldwide poultry industry, the sustained expansion of the harvesting area of cereal crops that are more resistant to climate change is essential. Cereals are the main component of poultry feed. Conventionally, corn and wheat are most widely used for this purpose

    Divergent trajectories of cellular bioenergetics, intermediary metabolism and systemic redox status in survivors and non-survivors of critical illness.

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    BACKGROUND: Numerous pathologies result in multiple-organ failure, which is thought to be a direct consequence of compromised cellular bioenergetic status. Neither the nature of this phenotype nor its relevance to survival are well understood, limiting the efficacy of modern life-support. METHODS: To explore the hypothesis that survival from critical illness relates to changes in cellular bioenergetics, we combined assessment of mitochondrial respiration with metabolomic, lipidomic and redox profiling in skeletal muscle and blood, at multiple timepoints, in 21 critically ill patients and 12 reference patients. RESULTS: We demonstrate an end-organ cellular phenotype in critical illness, characterized by preserved total energetic capacity, greater coupling efficiency and selectively lower capacity for complex I and fatty acid oxidation (FAO)-supported respiration in skeletal muscle, compared to health. In survivors, complex I capacity at 48 h was 27% lower than in non-survivors (p = 0.01), but tended to increase by day 7, with no such recovery observed in non-survivors. By day 7, survivors' FAO enzyme activity was double that of non-survivors (p = 0.048), in whom plasma triacylglycerol accumulated. Increases in both cellular oxidative stress and reductive drive were evident in early critical illness compared to health. Initially, non-survivors demonstrated greater plasma total antioxidant capacity but ultimately higher lipid peroxidation compared to survivors. These alterations were mirrored by greater levels of circulating total free thiol and nitrosated species, consistent with greater reductive stress and vascular inflammation, in non-survivors compared to survivors. In contrast, no clear differences in systemic inflammatory markers were observed between the two groups. CONCLUSION: Critical illness is associated with rapid, specific and coordinated alterations in the cellular respiratory machinery, intermediary metabolism and redox response, with different trajectories in survivors and non-survivors. Unravelling the cellular and molecular foundation of human resilience may enable the development of more effective life-support strategies.MRC, Evelyn Trust, Intensive Care Society, Royal Free Charit

    The echo-transponder electrode catheter: A new method for mapping the left ventricle

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    AbstractThe ability to locate catheter position in the left ventricle with respect to endocardial landmarks might enhance the accuracy of ventricular tachycardia mapping. An echotransponder system (Telectronics, Inc.) was compared with biplane fluoroscopy for left ventricular endocardial mapping. A 6F electrode catheter was modified with the addition of a piezoelectric crystal 5 mm from the tip. This crystal was connected to a transponder that received and transmitted ultrasound, resulting in a discrete artifact on the two-dimensional echocardiographic image corresponding to the position of the catheter tip.Catheters were introduced percutaneously into the left ventricle of nine anesthetized dogs. Two-dimensional echotransponder and biplane fluoroscopic images were recorded on videotape with the catheter at multiple endocardial sites. Catheter location was marked by delivering radiofrequency current to the distal electrode, creating a small endocardial lesion. Catheter location by echo-transponder and by fluoroscopy were compared with lesion location without knowledge of other data. Location by echo-transponder was 8.7 ± 5.1 mm from the center of the radiofrequency lesion versus 14 + 7.8 mm by fluoroscopy (n = 15, p = 0.023). Echo-transponder localization is more precise than is biplane fluoroscopy and may enhance the accuracy of left ventricular eledrophysiologic mapping

    Near Resonant Spatial Images of Confined Bose-Einstein Condensates in the '4D' Magnetic Bottle

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    We present quantitative measurements of the spatial density profile of Bose-Einstein condensates of sodium atoms confined in a new '4D' magnetic bottle. The condensates are imaged in transmission with near resonant laser light. We demonstrate that the Thomas-Fermi surface of a condensate can be determined to better than 1%. More generally, we obtain excellent agreement with mean-field theory. We conclude that precision measurements of atomic scattering lengths and interactions between phase separated cold atoms in a harmonic trap can be measured with high precision using this method.Comment: 15 pages, 3 figures. Submitted 10/30/97, accepted for publication in Phys. Rev. A Rapid Com
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