Lossy compression is widely used to decrease the size of multichannel remote sensing data. Alongside this positive effect, lossy compression may lead to a negative outcome as making worse image ...classification. Thus, if possible, lossy compression should be carried out carefully, controlling the quality of compressed images. In this paper, a dependence between classification accuracy of maximum likelihood and neural network classifiers applied to three-channel test and real-life images and quality of compressed images characterized by standard and visual quality metrics is studied. The following is demonstrated. First, a classification accuracy starts to decrease faster when image quality due to compression ratio increasing reaches a distortion visibility threshold. Second, the classes with a wider distribution of features start to “take pixels” from classes with narrower distributions of features. Third, a classification accuracy might depend essentially on the training methodology, i.e., whether features are determined from original data or compressed images. Finally, the drawbacks of pixel-wise classification are shown and some recommendations on how to improve classification accuracy are given.
Neuronal excitotoxicity which is induced by exposure to excessive extracellular glutamate is shown to be involved in neuronal cell death in acute brain injury and a number of neurological diseases. ...High concentration of glutamate induces calcium deregulation which results in mitochondrial calcium overload and mitochondrial depolarization that triggers the mechanism of cell death. Inhibition of mitochondrial calcium uptake could be potentially neuroprotective but complete inhibition of mitochondrial calcium uniporter could result in the loss of some physiological processes linked to Ca
2+
in mitochondria. Here, we found that a novel compound, TG-2112x, can inhibit only the lower concentrations mitochondrial calcium uptake (induced by 100 nM-5 μM) but not the uptake induced by higher concentrations of calcium (10 μM and higher). This effect was not associated with changes in mitochondrial membrane potential and cellular respiration. However, a pre-treatment of neurons with TG-2112x protected the neurons against calcium overload upon application of toxic concentrations of glutamate. Thus, sequestration of mitochondrial calcium uptake protected the neurons against glutamate-induced mitochondrial depolarization and cell death. In our hands, TG-2112x was also protective against ionomycin-induced cell death. Hence, low rate mitochondrial calcium uptake plays an underestimated role in mitochondrial function, and its inhibition could protect neurons against calcium overload and cell death in glutamate excitotoxicity.
With each passing year since the Chernobyl accident of 1986, more questions arise about the potential for organisms to adapt to radiation exposure. Often this is thought to be attributed to somatic ...and germline mutation rates in various organisms. We analyzed the adaptability of native Arabidopsis plants collected from areas with different levels of contamination around the Chernobyl nuclear power plant from 1986 to 1992. Notably, progeny of Chernobyl plants resisted higher concentrations of the mutagens Rose Bengal and methyl methane sulfonate. We analyzed the possible molecular mechanisms of their resistance to mutagens and found a more than 10-fold lower frequency of extrachromosomal homologous recombination, significant differences in the expression of radical scavenging (CAT1 and FSD3) and DNA-repair (RAD1 and RAD51-like) genes upon exposure to mutagens (Rose Bengal and x-rays), and a higher level of global genome methylation. This data suggests that adaptation to ionizing radiation is a complex process involving epigenetic regulation of gene expression and genome stabilization that improves plants' resistance to environmental mutagens.
We have previously demonstrated that human vaginal Lactobacillus crispatus 2029 (LC2029) strain is highly adhesive to cervicovaginal epithelial cells, exhibits antagonistic activity against ...genitourinary pathogens and expresses surface-layer protein (Slp). The aims of the present study were elucidation of Slp structural and immunomodulatory characteristics and its roles in protective properties of the whole vaginal LC2029 bacteria against foodborne pathogens. Enteric Caco-2 and colon HT-29 cell lines were used as the in vitro models of the human intestinal epithelial layer. LC2029 strain has two homologous surface-layer (S-layer) genes, slp1 and slp2. Whilst we found no evidence for the expression of slp1 under the growth conditions used, a very high level of expression of the slp2 gene was detected. C-terminal part of the amino sequence of Slp2 protein was found to be highly similar to that of the conserved C-terminal region of SlpA protein of L. crispatus Zj001 isolated from pig intestines and CbsA protein of L. crispatus JCM5810 isolated from chicken intestines, and was substantially variable at the N-terminal and middle regions. The amino acid sequence identity between SlpA and CbsA was as high as 84%, whilst the identity levels of these sequences with that of Slp2 were only 49% and 50% (respectively). LC2029 strain was found to be both acid and bile tolerant. Survival in simulated gastric and intestinal juices of LC2029 cells unable to produce Slp2 was reduced by 2–3 logs. Vaginal L. crispatus 1385 (LC1385) strain not expressing Slp was also very sensitive to gastric and intestinal stresses. Slp2 was found to be non-covalently bound to the surface of the bacterium, acting as an adhesin and facilitating interaction of LC2029 lactobacilli with the host immature or fully differentiated Caco-2 cells, as well as HT-29 cells. No toxicity to or damage of Caco-2 or HT-29 epithelial cells were detected after 24 h of colonization by LC2029 lactobacilli. Both Slp2 protein and LC2029 cells induced NF-kB activation in Caco-2 and HT-29 cells, but did not induce expression of innate immunity mediators Il-8, Il-1β, and TNF-α. Slp2 and LC2029 inhibited Il-8 production in Caco-2 and HT-29 cells induced by MALP-2 and increased production of anti-inflammatory cytokine Il-6. Slp2 inhibited production of CXCL1 and RANTES by Caco-2 cells during differentiation and maturation process within 15 days. Culturing Caco-2 and HT-29 cells in the presence of Slp2 increased adhesion of bifidobacteria BLI-2780 to these enterocytes. Upon binding to Caco-2 and HT-29 cells, Slp2 protein and LC2029 lactobacilli were recognized by toll-like receptors (TLR) 2/6. It was shown that LC2029 strain is a strong co-aggregator of foodborne pathogens Campylobacter jejuni, Salmonella enteritidis, and Escherichia coli O157:H used in this study. The Slp2 was responsible for the ability of LC2029 to co-aggregate these enteropathogens. Slp2 and intact LC2029 lactobacilli inhibited foodborne pathogen-induced activation of caspase-9 and caspase-3 as apoptotic biomarkers in Caco-2 and HT-29 cells. In addition, Slp2 and Slp2-positive LC2029 strain reduced adhesion of tested pathogenic bacteria to Caco-2 and HT-29 cells. Slp2-positive LC2029 strain but not Slp2 alone provided bactericidal effect on foodborne pathogens. These results suggest a range of mechanisms involved in inhibition of growth, viability, and cell-adhesion properties of pathogenic Proteobacteria by the Slp2 producing LC2029, which may be useful in treatment of necrotizing enterocolitis (NEC) in newborns and foodborne infectious diseases in children and adults, increasing the colonization resistance and maintaining the intestinal homeostasis.
We have previously demonstrated the ability of the human vaginal strain Lactobacillus crispatus 2029 (LC2029) for strong adhesion to cervicovaginal epithelial cells, expression of the surface layer ...protein 2 (Slp2), and antagonistic activity against urogenital pathogens. Slp2 forms regular two-dimensional structure around the LC2029 cells,which is secreted into the medium and inhibits intestinal pathogen-induced activation of caspase-9 and caspase-3 in the human intestinal Caco-2 cells. Here, we elucidated the effects of soluble Slp2 on adhesion of proteobacteria pathogens inducing necrotizing enterocolitis (NEC), such as Escherichia coli ATCC E 2348/69, E. coli ATCC 31705, Salmonella Enteritidis ATCC 13076, Campylobacter jejuni ATCC 29428, and Pseudomonas aeruginosa ATCC 27853 to Caco-2 cells, as well as on growth promotion, differentiation, vascular endothelial growth factor (VEGF) production, and intestinal barrier function of Caco-2 cell monolayers. Slp2 acts as anti-adhesion agent for NEC-inducing proteobacteria, promotes growth of immature Caco-2 cells and their differentiation, and enhances expression and functional activity of sucrase, lactase, and alkaline phosphatase. Slp2 stimulates VEGF production, decreases paracellular permeability, and increases transepithelial electrical resistance, strengthening barrier function of Caco-2 cell monolayers. These data support the important role of Slp2 in the early postnatal development of the human small intestine enterocytes.
•A microarray-based method was evaluated to identify ctDNA BRAF mutations in melanoma patients.•The presence of BRAF mutations in cfDNA correlates with tumor progression (P=0.005).•Increased levels ...of cfDNA correlate with tumor progression (P=0.02).•Coincidence of genotypes between the tumor DNA and ctDNA was 65%.
Background: Circulating tumor DNA (ctDNA) holds great potential for cancer therapy and can provide diagnostic and prognostic information before and during treatment.
Methods: Plasma DNA samples from 97 melanoma patients, 20 healthy donors and 3 patients with benign skin tumors were analyzed by microarray analysis and droplet digital PCR (ddPCR).
Results: A microarray for simultaneous detection of six BRAF V600 mutations in ctDNA has been developed. The method allows the detection of 0.05% mutated DNA from WT DNA background. For paired samples (pre-surgery plasma and tumor tissue) isolated from 74 patients, the concordance of genotypes between tumor DNA and ctDNA was 65% (48/74). BRAF mutations in ctDNA were detected in 27/50 patients with BRAF-positive tumors and in 3/24 patients with BRAF wild-type tumors. The presence of ctDNA BRAF mutations in 23 plasma samples from melanoma patients undergoing therapy correlated significantly with tumor progression (P=0.005). The increase in cell-free DNA levels measured by ddPCR also correlated with disease progression (P=0.02). The concordance of results obtained by microarray identification of BRAF mutations and those obtained by ddPCR was 91%.
Conclusion: The novel microarray-based approach can be a useful non-invasive tool for accurate identification of ctDNA BRAF mutations to monitor disease progression.
Efficiency analysis of color image filtering Fevralev, Dmitriy V; Ponomarenko, Nikolay N; Lukin, Vladimir V ...
EURASIP journal on advances in signal processing,
15/8, Letnik:
2011, Številka:
1
Journal Article
Recenzirano
Odprti dostop
This article addresses under which conditions filtering can visibly improve the image quality. The key points are the following. First, we analyze filtering efficiency for 25 test images, from the ...color image database TID2008. This database allows assessing filter efficiency for images corrupted by different noise types for several levels of noise variance. Second, the limit of filtering efficiency is determined for independent and identically distributed (i.i.d.) additive noise and compared to the output mean square error of state-of-the-art filters. Third, component-wise and vector denoising is studied, where the latter approach is demonstrated to be more efficient. Fourth, using of modern visual quality metrics, we determine that for which levels of i.i.d. and spatially correlated noise the noise in original images or residual noise and distortions because of filtering in output images are practically invisible. We also demonstrate that it is possible to roughly estimate whether or not the visual quality can clearly be improved by filtering.
A problem of predicting compression ratio (CR) for lossy image compression methods based on discrete cosine transform (DCT) is considered for remote sensing imaging as a main target application. We ...demonstrate that the noise presence in images leads to specific requirements to lossy image compression as well as to criteria used, and ways to meet these requirements. In particular, it is often desired to compress images in the neighborhood of optimal operation point (OOP) where a compressed image might be closer to the corresponding noise-free one compared to noisy (original, uncompressed) counterpart. In this paper, first, we consider a problem of predicting CR for compressing noisy images in OOP neighborhood. Several statistical parameters calculated in DCT domain in 8 × 8 pixel blocks are used for this. The factors that influence a prediction accuracy and the ways to improve this accuracy are discussed. Next, we show that there is a statistical parameter that does not require any a priori information on noise properties, and that can be used to predict CR with a high accuracy without any necessity to apply multiple image compression/decompression procedures. The proposed methods are thoroughly tested for two DCT-based image coders applied to component-wise lossy compression of hyperspectral data. Finally, a modification of the prediction approach for 3-D compression of multichannel images is proposed.
Heterotrimeric G proteins are immediate transducers of G protein-coupled receptors-the biggest receptor family in metazoans-and play innumerate functions in health and disease. A set of de novo point ...mutations in
and
, the genes encoding the α-subunits (Gαo and Gαi1, respectively) of the heterotrimeric G proteins, have been described to cause pediatric encephalopathies represented by epileptic seizures, movement disorders, developmental delay, intellectual disability, and signs of neurodegeneration. Among such mutations, the Gln52Pro substitutions have been previously identified in
and
. Here, we describe the case of an infant with another mutation in the same site, Gln52Arg. The patient manifested epileptic and movement disorders and a developmental delay, at the onset of 1.5 weeks after birth. We have analyzed biochemical and cellular properties of the three types of dominant pathogenic mutants in the Gln52 position described so far: GαoGln52Pro, Gαi1Gln52Pro, and the novel GαoGln52Arg. At the biochemical level, the three mutant proteins are deficient in binding and hydrolyzing GTP, which is the fundamental function of the healthy G proteins. At the cellular level, the mutants are defective in the interaction with partner proteins recognizing either the GDP-loaded or the GTP-loaded forms of Gαo. Further, of the two intracellular sites of Gαo localization, plasma membrane and Golgi, the former is strongly reduced for the mutant proteins. We conclude that the point mutations at Gln52 inactivate the Gαo and Gαi1 proteins leading to aberrant intracellular localization and partner protein interactions. These features likely lie at the core of the molecular etiology of pediatric encephalopathies associated with the codon 52 mutations in
/
.
Previously, the protective role of the S-layer protein 2 (Slp2) of the vaginal
2029 (LC2029) strain against foodborne pathogens
,
serovar Enteritidis, and
O157:H was demonstrated. We demonstrate the ...new roles of the Slp2-positive LC2029 strain and soluble Slp2 against
infections. We show that LC2029 bacteria can adhere to the surface of the cervical epithelial HeLa cells, prevent their contact with
, and block yeast transition to a pathogenic hyphal form. Surface-bound Slp2 provides the ability for LC2029 to co-aggregate with various
strains, including clinical isolates.
-induced necrotizing epithelial damage is reduced by colonization with the Slp2-positive LC2029 strain. Slp2 inhibits the adhesion of various strains of
to different human epithelial cells, blocks yeast transition to a pathogenic hyphal form, and prevents the colonization and pathogenic infiltration of mucosal barriers. Only Slp2 and LC2029 bacteria stimulate the production of protective human β-defensin 3 in various epithelial cells. These findings support the anti-
potential of the probiotic LC2029 strain and Slp2 and form the basis for further research on their ability to prevent and manage invasive
infections.
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