TAS-116, a Well-Tolerated Hsp90 Inhibitor,Prevents the Activation of the NLRP3 Inflammasome in Human Retinal Pigment Epithelial Cells

Chronic inflammation has been associated with several chronic diseases, such as age-related macular degeneration (AMD). The NLRP3 inflammasome is a central proinflammatory signaling complex that triggers caspase-1 activation leading to the maturation of IL-1β. We have previously shown that the inhibition of the chaperone protein, Hsp90, prevents NLRP3 activation in human retinal pigment epithelial (RPE) cells; these are cells which play a central role in the pathogenesis of AMD. In that study, we used a well-known Hsp90 inhibitor geldanamycin, but it cannot be used as a therapy due to its adverse effects, including ocular toxicity. Here, we have tested the effects of a novel Hsp90 inhibitor, TAS-116, on NLRP3 activation using geldanamycin as a reference compound. Using our existing protocol, inflammasome activation was induced in IL-1α-primed ARPE-19 cells with the proteasome and autophagy inhibitors MG-132 and bafilomycin A1, respectively. Intracellular caspase-1 activity was determined using a commercial caspase-1 activity kit and the FLICA assay. The levels of IL-1β were measured from cell culture medium samples by ELISA. Cell viability was monitored by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and lactate dehydrogenase (LDH) measurements. Our findings show that TAS-116 could prevent the activation of caspase-1, subsequently reducing the release of mature IL-1β. TAS-116 has a better in vitro therapeutic index than geldanamycin. In summary, TAS-116 appears to be a well-tolerated Hsp90 inhibitor, with the capability to prevent the activation of the NLRP3 inflammasome in human RPE cells.     

Magnetically Controlled Carbonate Nanocomposite with Ciprofloxacin for Biofilm Eradication

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.     

Are there so many sons per node in a wireless sensor network data aggregation tree?

Some authors seem to believe that the average number of sons in a Wireless Sensor Network (WSN) data aggregation tree can be kept constant, even when the distances from the sink increase. But this assumption is impossible to stand in a dense and uniformly deployed network, as the number of nodes in a given level would grow exponentially, while the perimeter just grows linearly. In this letter, it is shown that the average number of sons of a given tree node is in average a quite low number, slightly higher than one, and that it tends to 1, as the distance to sink, or node depth, increases, both for 2-D, and for 3-D WSNs.     

Conditioned and unconditioned fear organized in the inferior colliculus are differentially sensitive to injections of muscimol into the basolateral nucleus of the amygdala.

Chemical stimulation of the inferior colliculus (IC) with semicarbazide--an inhibitor of the gamma aminobutyric acid synthesizing enzyme--functions as an unconditioned stimulus in the conditioned place aversion test (CPA), and electrolytic lesions of the basolateral amygdala (BLA) enhance the aversiveness of the IC stimulation. This study examined the effects of inactivation of the BLA with muscimol on the conditioned and unconditioned fear using semicarbazide injections into the IC of rats subjected to conditioned (CPA) or unconditioned (open field) fear tests. In both tests, the rats were injected with semicarbazide or saline into the IC and muscimol or saline into the BLA. Muscimol decreased the CPA and increased the unconditioned fear elicited by IC injections of semicarbazide. These findings indicate that distinct modulatory mechanisms in the BLA are recruited during the conditioned and unconditioned fear triggered by IC activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The yeast rRNA biosynthesis factor Ebp2p is also required for efficient nuclear division

Molecular genetic analysis of the yeast Ebp2 protein has revealed that it is an essential, nucleolar protein that functions in the rRNA biosynthesis pathway. Temperature-sensitive ebp2-1 mutants are defective in the processing of the 27 SA precursor rRNA, and the point substitutions that disrupt this activity cluster towards the central, more highly conserved region of the Ebp2 protein. We report here that other ebp2 mutants exhibit deficiencies associated with defects in chromosome segregation. Yeast cells bearing a 50 amino acid C-terminal truncation allele (ebp2 delta C50) display a slow-growth phenotype and exhibit an increased percentage of cells with the nucleus positioned at the bud neck. The ebp2-1 and ebp2 delta C50 alleles genetically complement each other, and ebp2 delta C50 mutants exhibit nuclear division defects that are distinct from the rRNA biosynthesis-related phenotypes of ebp2-1 mutants. Cytological and FACS analysis of the ebp2 delta C50 deletion mutants indicate that the chromosome segregation related activities of the Ebp2 protein are monitored by Mad2p, a mitotic checkpoint protein. The finding that yeast Ebp2p functions in nuclear division is consistent with the growing body of evidence that supports the role that human EBP2 plays in chromosome segregation.     

Ontologies: How can They be Built?

Ontologies are an important component in many areas, such as knowledge management and organization, electronic commerce and information retrieval and extraction. Several methodologies for ontology building have been proposed. In this article, we provide an overview of ontology building. We start by characterizing the ontology building process and its life cycle. We present the most representative methodologies for building ontologies from scratch, and the proposed techniques, guidelines and methods to help in the construction task. We analyze and compare these methodologies. We describe current research issues in ontology reuse. Finally, we discuss the current trends in ontology building and its future challenges, namely, the new issues for building ontologies for the Semantic Web.     

Improved emission uniformity from a liquid-jet laser-plasma extreme-ultraviolet source

Many modern compact soft-x-ray and extreme-ultraviolet (EUV) imaging systems operate with small fields of view and therefore benefit from the use of small high-brightness sources. Such systems include water-window microscopes and EUV lithography tools. We show that the photon losses in such systems can be minimized while uniformity of object-plane illumination is maintained by controlled scanning of the source. The improved collection efficiency is demonstrated both theoretically and experimentally for a scanned laser-plasma source compared with static sources. A prospective aerial image microscope and a liquid-xenon-jet laser-plasma source are offered as examples of modern imaging tools that may benefit from such scanning of the source.     

Noise reduction in directional signals using multiple morse wavelets illustrated on quadrature Doppler ultrasound

The use of multiple complex-valued Morse wavelets for the scalogram study of signals which are unidirectional at any time, but are bidirectional overall is considered. These wavelets are well-suited to identifying the forward and reverse components. Scalogram averaging which is possible due to the multiplicity of the complex-valued wavelets leads to a scalogram with reduced noise. Information from positive and negative scales can then be used to estimate a final "cleaned" scalogram. Quadrature Doppler ultrasound blood flow in the femoral artery is taken as an example to clearly illustrate the noise reduction.     

Production and characterization of pure and Cr<Superscript>3+</Superscript>-doped hydroxyapatite for biomedical applications as fluorescent probes

Pure and Cr³⁺-doped hydroxyapatite (HAP) were prepared via chemical precipitation route. The XRD measurements revealed that the typical HAP powder pattern was obtained. SEM analysis indicated that aggregates of nanoparticles were formed. EDX analysis indicates that the [Ca]/[P] concentration ratio was higher than the expected values but can be explained by the presence of carbonate groups as dopants. The optical absorption spectra of the doped samples presented absorption bands typical of Cr³⁺ occupying to different crystalline sites. From the position of the bands, it was possible to estimate the crystal field parameters for both sites of Cr³⁺ in the HAP matrix. The emission spectra of the Cr-doped samples were also investigated and typical transitions of the dopant ion, in trivalent state, were identified. The potential use of the Cr³⁺-HAP as fluorescent probes for medical applications was discussed.