Method for Quantitative Study of Airway Functional Microanatomy Using Micro-Optical Coherence Tomography

We demonstrate the use of a high resolution form of optical coherence tomography, termed micro-OCT (μOCT), for investigating the functional microanatomy of airway epithelia. μOCT captures several key parameters governing the function of the airway surface (airway surface liquid depth, periciliary liquid depth, ciliary function including beat frequency, and mucociliary transport rate) from the same series of images and without exogenous particles or labels, enabling non-invasive study of dynamic phenomena. Additionally, the high resolution of μOCT reveals distinguishable phases of the ciliary stroke pattern and glandular extrusion. Images and functional measurements from primary human bronchial epithelial cell cultures and excised tissue are presented and compared with measurements using existing gold standard methods. Active secretion from mucus glands in tissue, a key parameter of epithelial function, was also observed and quantified.     

Microplate quantification of plant leaf superoxide dismutases

Superoxide dismutases (SODs) catalyze the dismutation of superoxide radicals in a broad range of organisms, including plants. Quantification of SOD activity in crude plant extracts has been problematic due to the presence of compounds that interfere with the dose-response of the assay. Although strategies exist to partially purify SODs from plant extracts, the requirement for purification limits the rapidity and practical number of assays that can be conducted. In this article, we describe modification of a procedure using o-dianisidine as substrate that permits relatively rapid quantification of SOD activity in crude leaf extracts in a microplate format. The method employs the use of a commercial apparatus that permits lysis of 12 tissue samples at once and the use of Pipes buffer to reduce interference from compounds present in crude leaf extracts. The assay provided a linear response from 1 to 50 units of SOD. The utility of the assay was demonstrated using tissue extracts prepared from a group of taxonomically diverse plants. Reaction rates with tissue extracts from two grasses were linear for at least 60 min. Tissues of certain species contained interfering compounds, most of which could be removed by ultrafiltration. The presence of plant catalases, peroxidases, and ascorbate in physiological quantities did not interfere with the assay. This approach provides a means to quantify SOD activity in relatively large numbers of plant samples provided that the possibility for the presence of interfering compounds is considered. The presence of interfering compounds in certain plant tissues necessitates caution in interpreting the effects of plant stresses on SOD.     

Synonymous codon usage pattern among the S,M, and L segments in Crimean-congo hemorrhagic fever virus

Crimean-Congo hemorrhagic fever (CCHF) virus is one among the major zoonosis viral diseases that use the Hyalomma ticks as their transmission vector to cause viral infection to the human and mammalian community. The fatality of infectious is high across the world especially in Africa, Asia, Middle East, and Europe. This study regarding codon usage bias of S, M, and L segments of the CCHF virus pertaining to the host Homo sapiens, reveals in-depth information about the evolutionary characteristics of CCHFV. Relative Synonymous Codon Usage (RSCU), Effective number of codons (ENC) were calculated, to determine the codon usage pattern in each segment. Correlation analysis between Codon adaptation index (CAI), GRAVY (Hydrophobicity), AROMO (Aromaticity), and nucleotide composition revealed bias in the codon usage pattern. There was no strong codon bias found among any segments of the CCHF virus, indicating both the factors i.e., natural selection and mutational pressure shapes the codon usage bias.     

The approximate entropy of the electromyographic signals of tremor correlates with the osmotic fragility of human erythrocytes

Background  

The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics.     

Long-term landscape changes in vegetation structure: fire management in the wetlands of KwaMbonambi,South Africa

In wetlands the effects of fire on vegetation dynamics are somewhat uncertain. A change detection analysis in the herbaceous wetlands of KwaMbonambi, South Africa, which were subject to frequent fires, revealed that in 1937 the study area comprised grassland (69%), herbaceous wetland (25%), indigenous swamp forest (4%) and tree plantations (1%). However, by 1970, tree plantations occupied 78% of the landscape and grasslands and herbaceous wetlands had declined to 9% and 6%, respectively, whereas indigenous swamp forest had increased to 6%. By 2009 tree plantations had been removed from the wetland areas. Despite this opportunity for herbaceous wetlands to recover their historical extent, they decreased to only 2%, mostly changing to indigenous swamp forest or to an herbaceous/fern (Stenochlaena tenuifolia)/woodland mosaic. Fire records showed suppression of fire to be an important contributing factor, particularly in wetlands that had been disturbed by tree plantations, although subsequently removed. A pilot burning experiment revealed that S. tenuifolia did not inhibit fire. It is therefore practicable to increase fire frequency to prevent the mosaic developing into forest. A conceptual model of the influence of fire regime on wetland vegetation type is presented and priorities for further research on wetlands and fire are recommended.     

Production of the lantibiotic salivaricin A and its variants by oral streptococci and use of a specific induction assay to detect their presence in human saliva

Salivaricin A (SalA), the first Streptococcus salivarius lantibiotic to be characterized, appears to be inhibitory to most Streptococcus pyogenes strains. A variant of the SalA structural gene (salA1) is present in more than 90% of S. pyogenes strains, but only strains of M serotype 4 and T pattern 4 produce the biologically active peptide. The present study identifies four additional variants (salA2 to salA5) of the SalA structural gene and demonstrates that each of the corresponding inhibitory peptides (SalA2 to SalA5) is produced in vitro. These variants appear to be similar to SalA and SalA1 in their inhibitory activity against Micrococcus luteus and in their ability to act as inducers of SalA production. It had previously been shown that S. pyogenes strain SF370 had a deletion (of approximately 2.5 kb) in the salM and salT genes of the salA1 locus. In the present study, several additional characteristic deletions within the salA1 loci were identified. S. pyogenes strains of the same M serotype all share the same salA1 locus structure. Since S. salivarius is a predominant member of the normal oral flora of healthy humans, strains producing anti-S. pyogenes lantibiotics, such as SalA, may have excellent potential for use as oral probiotics. In the present study, we have used a highly specific SalA induction system to directly detect the presence of SalA in the saliva of humans who either naturally harbor populations of SalA-producing S. salivarius or who have been colonized with the SalA2-producing probiotic S. salivarius K12.     

Production of the Lantibiotic Salivaricin A and Its Variants by Oral Streptococci and Use of a Specific Induction Assay To Detect Their Presence in Human Saliva

Salivaricin A (SalA), the first Streptococcus salivarius lantibiotic to be characterized, appears to be inhibitory to most Streptococcus pyogenes strains. A variant of the SalA structural gene (salA1) is present in more than 90% of S. pyogenes strains, but only strains of M serotype 4 and T pattern 4 produce the biologically active peptide. The present study identifies four additional variants (salA2 to salA5) of the SalA structural gene and demonstrates that each of the corresponding inhibitory peptides (SalA2 to SalA5) is produced in vitro. These variants appear to be similar to SalA and SalA1 in their inhibitory activity against Micrococcus luteus and in their ability to act as inducers of SalA production. It had previously been shown that S. pyogenes strain SF370 had a deletion (of approximately 2.5 kb) in the salM and salT genes of the salA1 locus. In the present study, several additional characteristic deletions within the salA1 loci were identified. S. pyogenes strains of the same M serotype all share the same salA1 locus structure. Since S. salivarius is a predominant member of the normal oral flora of healthy humans, strains producing anti-S. pyogenes lantibiotics, such as SalA, may have excellent potential for use as oral probiotics. In the present study, we have used a highly specific SalA induction system to directly detect the presence of SalA in the saliva of humans who either naturally harbor populations of SalA-producing S. salivarius or who have been colonized with the SalA2-producing probiotic S. salivarius K12.     

Thalidomide attenuates nitric oxide mediated angiogenesis by blocking migration of endothelial cells

Background  

Thalidomide is an immunomodulatory agent, which arrests angiogenesis. The mechanism of anti-angiogenic activity of thalidomide is not fully understood. As nitric oxide is involved in angiogenesis, we speculate a cross-talk between thalidomide and nitric oxide signaling pathway to define angiogenesis. The aim of present study is to understand the mechanistic aspects of thalidomide-mediated attenuation of angiogenesis induced by nitric oxide at the cellular level.     

Neural mechanisms of context-dependent processing of CO2 avoidance behavior in fruit flies

The fruit fly, Drosophila melanogaster, innately avoids even low levels of CO₂. CO₂ is part of the so-called Drosophila stress odor produced by stressed flies, but also a byproduct of fermenting fruit, a main food source, making the strong avoidance behavior somewhat surprising. Therefore, we addressed whether feeding states might influence the fly’s behavior and processing of CO₂. In a recent report, we showed that this innate behavior is differentially processed and modified according to the feeding state of the fly. Interestingly, we found that hungry flies require the function of the mushroom body, a higher brain center required for olfactory learning and memory, but thought to be dispensable for innate olfactory behaviors. In addition, we anatomically and functionally characterized a novel bilateral projection neuron connecting the CO₂ sensory input to the mushroom body. This neuron was essential for processing of CO₂ in the starved fly but not in the fed fly. In this Extra View article, we provide evidence for the potential involvement of the neuromodulator dopamine in state-dependent CO₂ avoidance behavior. Taken together, our work demonstrates that CO₂ avoidance behavior is mediated by alternative neural pathways in a context-dependent manner. Furthermore, it shows that the mushroom body is not only involved in processing of learned olfactory behavior, as previously suggested, but also in context-dependent innate olfaction.