Changes in the cross-sections of the nasal cavity assessed by acoustic rhinometry in the study population as a guideline for attempts to standardize nasal provocation tests.

Introduction: A specific difficulty in the standardization of nasal allergen challenge tests as measured by acoustic rhinometry is the lack of reference values measured according to dependent changes, for example height and weight/height- or weight-dependent changes. Human growth and development rates and other changes the human body undergoes throughout the lifetime depend closely on the environment, sex, and race. Aim: To assess selected anthropometric (body weight and height) and rhinometric (nasal cross-sectional areas) measurements concerning subject age and sex. Material and methods: The study was conducted in 633 subjects selected in multistage, stratified sampling (324 females and 309 males). Body weight and height were measured with a sliding weight scale and height measure. Nasal cavity cross-sectional areas were measured via acoustic rhinometry. Results: We observed parallel increases in the evaluated anthropometric measurements and nasal cavity cross-sectional areas both in males and females aged ≤ 14 years, with the two sexes starting to differ significantly in terms of those measurements over the age of 14 (p < 0.0001; p < 0.000001). The evaluated rhinometric measurements showed a greater correlation with height than with body weight. The time of the most diversified and dynamic changes in anthropomorphic measurements was the age of > 12 years: with boys demonstrating significantly higher mean values of height and body weight than girls. Conclusions: Height showed a better correlation with rhinometric measurements (cross-sectional area of the nasal cavity) in younger subjects (at their age of development) than in older ones.

The normal ranges of selected acoustic rhinometry parameters depending on age and sex-component of standarization in nasal provocation test.

Introduction: Acoustic rhinometry is a non-invasive method of measuring intranasal spaces. As one of the objective techniques for nasal patency, it plays a critical role in evaluating the nasal allergen challenge.Aim: To establish the typical ranges of selected AR parameters for age and sex. Material and methods: The study was conducted in a group of 583 randomly selected subjects (329 females and 254 males). Acoustic rhinometry was done before and 15 min after a two-time application of 0.1% solution of the decongestant xylomethazoline. The evaluated AR parameters (the cross-sectional area 1 (CSA-1) at the level of the isthmus nasi and the distance between the external nares and the isthmus nasi (dCSA-1)) were measured separately for both nasal cavities. Another evaluated parameter was the mean CSA measured 3 cm beyond CSA-1 on the AR curve (CSA-3). Results: The site of the minimum CSA on the acoustic rhinometry curve in the study group was the second notch on the acoustic rhinometry curve (CSA-1), corresponding to the nasal isthmus. With increasing age of the subjects, we observed a systematic increase in nasal spaces. The difference between sexes reached statistical significance at the ages of 17 years and older. Conclusions: The evaluated males show larger nasal cavity volumes than females. The difference between the sexes reaches statistical significance at older ages.

Global organization of neuronal activity only requires unstructured local connectivity.

Modern electrophysiological recordings simultaneously capture single-unit spiking activities of hundreds of neurons spread across large cortical distances. Yet, this parallel activity is often confined to relatively low-dimensional manifolds. This implies strong coordination also among neurons that are most likely not even connected. Here, we combine in vivo recordings with network models and theory to characterize the nature of mesoscopic coordination patterns in macaque motor cortex and to expose their origin: We find that heterogeneity in local connectivity supports network states with complex long-range cooperation between neurons that arises from multi-synaptic, short-range connections. Our theory explains the experimentally observed spatial organization of covariances in resting state recordings as well as the behaviorally related modulation of covariance patterns during a reach-to-grasp task. The ubiquity of heterogeneity in local cortical circuits suggests that the brain uses the described mechanism to flexibly adapt neuronal coordination to momentary demands.

On the Complexity of Resting State Spiking Activity in Monkey Motor Cortex.

Resting state has been established as a classical paradigm of brain activity studies, mostly based on large-scale measurements such as functional magnetic resonance imaging or magneto- and electroencephalography. This term typically refers to a behavioral state characterized by the absence of any task or stimuli. The corresponding neuronal activity is often called idle or ongoing. Numerous modeling studies on spiking neural networks claim to mimic such idle states, but compare their results with task- or stimulus-driven experiments, or to results from experiments with anesthetized subjects. Both approaches might lead to misleading conclusions. To provide a proper basis for comparing physiological and simulated network dynamics, we characterize simultaneously recorded single neurons' spiking activity in monkey motor cortex at rest and show the differences from spontaneous and task- or stimulus-induced movement conditions. We also distinguish between rest with open eyes and sleepy rest with eyes closed. The resting state with open eyes shows a significantly higher dimensionality, reduced firing rates, and less balance between population level excitation and inhibition than behavior-related states.

Impact of the Carbon Nanofillers Addition on Rheology and Absorption Ability of Composite Shear Thickening Fluids.

Synthesis and characterization of composite shear thickening fluids (STFs) containing carbon nanofillers are presented. Shear thickening fluids have attracted particular scientific and technological interest due to their unique ability to abruptly increase viscosity in the case of a sudden impact. The fluids have been developed as a potential component of products with high energy absorbing efficiency. This study reports on the rheological behavior, stability, and microstructure of the STFs modified with the following carbon nanofillers: multi-walled carbon nanotubes, reduced graphene oxide, graphene oxide, and carbon black. In the current experiment, the basic STF was made as a suspension of silica particles with a diameter of 500 nm in polypropylene glycol and with a molar mass of 2000 g/mol. The STF was modified with carbon nanofillers in the following proportions: 0.05, 0.15, and 0.25 vol.%. The addition of the carbon nanofillers modified the rheological behavior and impact absorption ability; for the STF containing 0.25 vol.% of carbon nanotubes, an increase of force absorption up to 12% was observed.

Mechanisms of fibrinogen adsorption on latex particles determined by zeta potential and AFM measurements.

The adsorption of fibrinogen on polystyrene latex particles was studied using the concentration depletion method combined with the AFM detection of residual protein after adsorption. Measurements were carried out for a pH range of 3.5-11 and an ionic strength range of 10(-3)-0.15 M NaCl. First, the bulk physicochemical properties of fibrinogen and the latex particle suspension were characterized for this range of pH and ionic strength. The zeta potential and the number of uncompensated (electrokinetic) charges on the protein were determined from microelectrophoretic measurements. It was revealed that fibrinogen molecules exhibited amphoteric characteristics, being on average positively charged for pH <5.8 (isolectric point) and negative otherwise. However, the latex particles did not show any isoelectric point, remaining strongly negative for this pH range. Afterward, systematic measurements of the electrophoretic mobility of fibrinogen-covered latex were carried out as a function of the amount of adsorbed protein, expressed as the surface concentration. A monotonic increase in the electrophoretic mobility (zeta potential) of the latex was observed in all cases, indicating a significant adsorption of fibrinogen on latex for pH below 11. It was also proven that fibrinogen adsorption was irreversible, with the maximum surface concentration varying between 2.5 and 5 × 10(3) µm(-2) (weight concentration of a bare molecule was 1.4 to 2.8 mg m(-2)). These measurements revealed two main adsorption mechanisms of fibrinogen: (i) the unoriented (random) mechanism prevailing for lower ionic strength, where adsorbing molecules significantly penetrate the fuzzy polymeric layer on the latex core and (ii) the side-on adsorption mechanism prevailing for pH > 5.8 and a higher ionic strength of 0.15 M. It was also shown that in the latter case, variations in the zeta potential with the protein coverage could be adequately described in terms of the electrokinetic model, previously formulated for planar substrate adsorption. On the basis of these experimental data, an efficient procedure of preparing fibrinogen-covered latex particles of controlled monolayer structure and coverage was envisaged.

Isomerization of the phytohormone precursor 12-oxophytodienoic acid (OPDA) in the insect gut: a mechanistic and computational study.

12-Oxophytodienoic acid (OPDA) is isomerized in the gut of herbivorous insects to tetrahydrodicranenone B (iso-OPDA). The transformation is achieved by a glutathione S-transferase present in the gut epithelium. Experiments with 9-[(2)H]-iso-OPDA demonstrated the complete retention of the deuterium atom in the product 11-[(2)H]-OPDA consistent with an intramolecular 1,3-hydrogen shift. Homology modeling based on the x-ray structure of a glutathione S-transferase from Anopheles gambiae revealed that the co-factor glutathione does not covalently bind to the substrate but appears to be involved in the initial deprotonation and enolization of the OPDA. The transformation resembles that of a mammalian GST-catalyzed isomerization of Δ(5)-3-ketosteroids to Δ(4)-3-ketosteroids or the conversion of prostaglandin A(1) to the biologically inactive prostaglandin B(1).

The phytohormone precursor OPDA is isomerized in the insect gut by a single, specific glutathione transferase.

Oxylipins play important roles in stress signaling in plants. The compound 12-oxophytodienoic acid (cis-OPDA) is an early biosynthetic precursor of jasmonic acid (JA), the key phytohormone orchestrating the plant anti-herbivore defense. When consumed by feeding Lepidopteran larvae, plant-derived cis-OPDA suffers rapid isomerization to iso-OPDA in the midgut and is excreted in the frass. Unlike OPDA epimerization (yielding trans-OPDA), the formation of iso-OPDA is enzyme-dependent, and is catalyzed by an inducible glutathione transferase (GSTs) from the larval gut. Purified GST fractions from the gut of Egyptian cotton leafworm (Spodoptera littoralis) and cotton bollworm (Helicoverpa armigera) both exhibited strong OPDA isomerization activity, most likely via transient formation of a glutathione-OPDA conjugate. Out of 16 cytosolic GST proteins cloned from the gut of cotton bollworm larvae and expressed in E. coli, only one catalyzed the OPDA isomerization. The biological function of the double bond shift might be seen in an inactivation of cis-OPDA, similar to the inactivation of prostaglandin A1 to prostaglandin B1 in mammalian tissue. The enzymatic isomerization is particularly widespread among generalist herbivores that have to cope with various amounts of cis-OPDA in their spectrum of host plants.

Involvement of siderophores in the reduction of metal-induced inhibition of auxin synthesis in Streptomyces spp.

Unlike synthetic metal chelators, microbe-assisted phytoremediation provides plants with natural metal-solubilizing chelators which do not constitute a potential source of environmental pollution. Concurrently with microbial chelators, plant growth promotion can be enhanced through bacterially-produced phytohormones. In this work, the simultaneous production of siderophores and auxins by Streptomyces was studied to gain insight for future application in plant growth and phytoremediation in a metal-contaminated soil. Standard auxin and siderophore detection assays indicated that all of the investigated Streptomyces strains can produce these metabolites simultaneously. However, Al(3+), Cd(2+), Cu(2+), Fe(3+) and Ni(2+), or a combination of Fe(3+) and Cd(2+), and Fe(3+) and Ni(2+) affected auxin production negatively, as revealed by spectrophotometry and gas chromatography-mass spectrometry. This effect was more dramatic in a siderophore-deficient mutant. In contrast, except for Fe, all the metals stimulated siderophore production. Mass spectrometry showed that siderophore and auxin-containing supernatants from a representative Streptomyces species contain three different hydroxamate siderophores, revealing the individual binding responses of these siderophores to Cd(2+) and Ni(2+), and thus, showing their auxin-stimulating effects. We conclude that siderophores promote auxin synthesis in the presence of Al(3+), Cd(2+), Cu(2+) and Ni(2+) by chelating these metals. Chelation makes the metals less able to inhibit the synthesis of auxins, and potentially increases the plant growth-promoting effects of auxins, which in turn enhances the phytoremediation potential of plants.

Effects of feeding Spodoptera littoralis on lima bean leaves: IV. Diurnal and nocturnal damage differentially initiate plant volatile emission.

Continuous mechanical damage initiates the rhythmic emission of volatiles in lima bean (Phaseolus lunatus) leaves; the emission resembles that induced by herbivore damage. The effect of diurnal versus nocturnal damage on the initiation of plant defense responses was investigated using MecWorm, a robotic device designed to reproduce tissue damage caused by herbivore attack. Lima bean leaves that were damaged by MecWorm during the photophase emitted maximal levels of beta-ocimene and (Z)-3-hexenyl acetate in the late photophase. Leaves damaged during the dark phase responded with the nocturnal emission of (Z)-3-hexenyl acetate, but with only low amounts of beta-ocimene; this emission was followed by an emission burst directly after the onset of light. In the presence of (13)CO(2), this light-dependent synthesis of beta-ocimene resulted in incorporation of 75% to 85% of (13)C, demonstrating that biosynthesis of beta-ocimene is almost exclusively fueled by the photosynthetic fixation of CO(2) along the plastidial 2-C-methyl-D-erythritol 4-P pathway. Jasmonic acid (JA) accumulated locally in direct response to the damage and led to immediate up-regulation of the P. lunatus beta-ocimene synthase gene (PlOS) independent of the phase, that is, light or dark. Nocturnal damage caused significantly higher concentrations of JA (approximately 2-3 times) along with enhanced expression levels of PlOS. Transgenic Arabidopsis thaliana transformed with PlOS promoter :: beta-glucuronidase fusion constructs confirmed expression of the enzyme at the wounded sites. In summary, damage-dependent JA levels directly control the expression level of PlOS, regardless of light or dark conditions, and photosynthesis is the major source for the early precursors of the 2-C-methyl-D-erythritol 4-P pathway.

Iso-OPDA: an early precursor of cis-jasmone in plants?

Cis-jasmone is a highly appreciated fragrance and plant-derived signal molecule that controls pollination, attracts parasitoids of attacking herbivores, and serves as an intra- and interspecific signal that controls gene expression. cis-Jasmone is produced from linolenic acid along the jasmonic acid cascade. In addition to the conversion of jasmonic acid into cis-jasmone, a novel pathway might exist that converts cis-oxophytodienoic acid (OPDA), an early precursor of jasmonic acid, into iso-OPDA. The planar iso-OPDA is degraded by beta-oxidation to 3,7-didehydrojasmonic acid, which yields cis-jasmone by spontaneous decarboxylation. The degradation of iso-OPDA to cis-jasmone is demonstrated for many plant species and the yeast Saccharomyces cerevisiae.

Functional identification and differential expression of 1-deoxy-D-xylulose 5-phosphate synthase in induced terpenoid resin formation of Norway spruce (Picea abies).

Conifers produce terpenoid-based oleoresins as constitutive and inducible defenses against herbivores and pathogens. Much information is available about the genes and enzymes of the late steps of oleoresin terpenoid biosynthesis in conifers, but almost nothing is known about the early steps which proceed via the methylerythritol phosphate (MEP) pathway. Here we report the cDNA cloning and functional identification of three Norway spruce (Picea abies) genes encoding 1-deoxy-D-xylulose 5-phosphate synthase (DXS), which catalyzes the first step of the MEP pathway, and their differential expression in the stems of young saplings. Among them are representatives of both types of plant DXS genes. A single type I DXS gene is constitutively expressed in bark tissue and not affected by wounding or fungal application. In contrast, two distinct type II DXS genes, PaDXS2A and PaDXS2B, showed increased transcript abundance after these treatments as did two other genes of the MEP pathway tested, 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) and 4-hydroxyl 3-methylbutenyl diphosphate reductase (HDR). We also measured gene expression in a Norway spruce cell suspension culture system that, like intact trees, accumulates monoterpenes after treatment with methyl jasmonate. These cell cultures were characterized by an up-regulation of monoterpene synthase gene transcripts and enzyme activity after elicitor treatment, as well as induced formation of octadecanoids, including jasmonic acid and 12-oxophytodienoic acid. Among the Type II DXS genes in cell cultures, PaDXS2A was induced by treatment with chitosan, methyl salicylate, and Ceratocystis polonica (a bark beetle-associated, blue-staining fungal pathogen of Norway spruce). However, PaDXS2B was induced by treatment with methyl jasmonate and chitosan, but was not affected by methyl salicylate or C. polonica. Our results suggest distinct functions of the three DXS genes in primary and defensive terpenoid metabolism in Norway spruce.

Rapid enzymatic isomerization of 12-oxophytodienoic acid in the gut of lepidopteran larvae.

In response to feeding larvae of the Mediterranean climbing cutworm (Spodoptera littoralis), leaves of the lima bean (Phaseolus lunatus) produce fatty acid-derived signaling compounds (oxylipins). The major products are the phytohormones jasmonic acid and its biosynthetic precursor 12-oxophytodienoic acid (OPDA), along with 13-hydroxy-12-oxooctadeca-9,15-dienoic acid, 9-hydroxy-12-oxooctadeca-10,15-dienoic acid (alpha- and gamma-ketol), as well as unsaturated aldehydes. Oxylipin production is highest at the feeding zone of the insect and decreases with distance from the damaged area. Accordingly, the feeding insect experiences high local concentrations of oxylipins, which are taken up into the alimentary canal and are finally excreted with the feces. In contrast to most other oxylipins, OPDA was not detectable in the insect's gut; instead the structurally related tetrahydrodicranenone B (iso-OPDA) was identified. Feeding experiments with deuterium-labeled OPDA proved that the isomerization is catalyzed by an enzyme from the insect's gut tissue. The phenomenon appears to be widespread among Lepidopteran larvae.

[Acoustic rhinometry--examination technique and discussion of the recommendation of the Committee for Standardisation of Acoustic Rhinometry, European Rhinologic Association ]. / Rynometria akustyczna--technika badania i omówienie zalecen Komitetu Standaryzacji Rynometrii Akustycznej Europejskiego Towarzystwa Rynologicznego.

Acoustic rhinometry (AR) is a technique of nasal patency assessment, ever more frequently used in clinical practice. As yet, no generally accepted recommendations has been developed concerning the method of examination performing. In the paper the technique of examination is presented and the recommendations of the Committee for Standardisation of Acoustic Rhinometry, European Rhinologic Association are discussed.

[Relationship between inflammation of upper and lower respiratory airways]. / Powiazania pomiedzy zapaleniami górnych i dolnych dróg oddechowych.

Dysfunction of the upper and lower airways frequently coexists, and they appear to share key elements of pathogenesis. Data from epidemiologic studies indicate that nasal symptoms are experienced by as many as 78% of patients with asthma and that asthma is experienced by as many as 38% of patients with allergic rhinitis. Among patients with nasal polyps 27-51% have asthma. Polyps of nasal mucosa usually exacerbates symptoms of concomitant asthma. Studies also have identified a temporal relation between the onset of rhinitis and asthma, with rhinitis frequently preceding the development of asthma. Patients with allergic rhinitis and no clinical evidence of asthma commonly exhibit nonspecific bronchial hyperresponsivenes. The mechanisms upper and lower airway dysfunction are under investigation. They include nasal-bronchial reflex, mouth breathing caused by nasal obstruction, and pulmonary aspiration of nasal contents. Nasal allergen challenge results in increases in lower airway reactivity within 30 minutes, suggesting a neural reflex. Improvements in asthma associated with increased nasal breathing may be the result of superior humidification, warming of inspired air, and decreased inhalation of airborne allergens. Postnasal drainage of inflammatory cells during sleep also may affect lower airway responsiveness. The effective management of allergic rhinitis relieves symptoms of asthma. A link between allergic rhinitis and asthma is evident from epidemiologic, pathophysiologic, and clinical studies. The development of differential diagnosis of rhinitis has multiplied their present classifications. This article presents classifications of rhinitis connected with lower airways dysfunction.