Pharmacokinetic study and the extraction efficiency of bulk and precipitated ibuprofen-imprinted polymer sorbents for gas chromatography and gas chromatography-mass spectrometry ibuprofen bio-analysis.

Bulk and precipitation polymerization methods were used to prepare ibuprofen-molecularly imprinted polymers. Molecularly imprinted polymer-bulk and -precipitation were synthesized in acetonitrile, likewise molecularly imprinted polymer-bulk (mixture) and molecularly imprinted polymer-precipitation (mixture) in a mixture of acetonitrile/toluene (75:25 v/v). N2 adsorption-desorption analysis data revealed that molecularly imprinted polymer-precipitation (mixture) has the highest specific surface area (200.74 m2 /g). The surface chemistry and morphology of the synthesized sorbents were investigated by Fourier-transform infrared analysis and scanning electron microscope micrographs respectively. The prepared sorbents in the mixture of solvents were used in a dispersive solid-phase extraction process for selective extraction and pre-concentration of ibuprofen from urine and human plasma samples. The detection limits were 62.91 and 7.89 ng/ml using molecularly imprinted polymer-bulk (mixture) and molecularly imprinted polymer-precipitation (mixture), respectively. Also, the sorbents showed selective behavior to extract ibuprofen in the presence of naproxen, fenoprofen, and ketoprofen. Overall, the results showed that the precipitation method in the mixture of acetonitrile/toluene resulted in the preparation of a sorbent with the highest extraction efficiency. Furthermore, a pharmacokinetic study was done. The maximum plasma concentration, the time required for maximum plasma concentration, and plasma half-life were 28.95 µg/ml, 2, and 2.39 h, respectively.

Modified activated carbon derived from chestnut oak shells as a new sorbent for the needle-trap extraction.

In this study, an acid-treated-activated carbon was prepared from chestnut oak shell carbonization followed by modification with hydrochloric acid/nitric acid and then used as a new sorbent for headspace needle-trap extraction of chlorophenol compounds from aqueous solutions. Different techniques, including scanning electron microscopy, nitrogen adsorption-desorption analysis, and Fourier transform-infrared spectroscopy were used for the characterization of the sorbents. The effects of some experimental parameters, including the temperature, pH, sorbent amount, and time of extraction were optimized. The developed method is fast and sensitive, providing low and sub ng/L detection limits. The limits of detection and quantification were in the range of 0.75-5 and 5-15 ng/ml, respectively, and the equilibrium time was 20 min. Wide linearity in the range of 15-2000 ng/L with R2  > 0.9993 was obtained. Repeatability of the method was accessed at 50, 100, and 200 ng/L concentration levels and RSD% of 5%-12% was achieved. The introduced method was applied for analyzing real water samples containing spiked chlorophenols, and the relative recovery values were found to be in the range of 84%-99% at the concentration levels of 50, 100 and 200 ng/L.

KSHV SOX mediated host shutoff: the molecular mechanism underlying mRNA transcript processing.

Onset of the lytic phase in the KSHV life cycle is accompanied by the rapid, global degradation of host (and viral) mRNA transcripts in a process termed host shutoff. Key to this destruction is the virally encoded alkaline exonuclease SOX. While SOX has been shown to possess an intrinsic RNase activity and a potential consensus sequence for endonucleolytic cleavage identified, the structures of the RNA substrates targeted remained unclear. Based on an analysis of three reported target transcripts, we were able to identify common structures and confirm that these are indeed degraded by SOX in vitro as well as predict the presence of such elements in the KSHV pre-microRNA transcript K12-2. From these studies, we were able to determine the crystal structure of SOX productively bound to a 31 nucleotide K12-2 fragment. This complex not only reveals the structural determinants required for RNA recognition and degradation but, together with biochemical and biophysical studies, reveals distinct roles for residues implicated in host shutoff. Our results further confirm that SOX and the host exoribonuclease Xrn1 act in concert to elicit the rapid degradation of mRNA substrates observed in vivo, and that the activities of the two ribonucleases are co-ordinated.

Improvement of solid-phase microextraction efficiency by the application of a carbon-nanotubes-based ternary microextraction fiber composite.

In this study, a novel technique is proposed for preparation of an efficient and unbreakable metal-wire-supported solid-phase microextraction fiber. A sol-gel film was deposited on electrophoretically deposited carbon nanotubes on a stainless-steel wire. The applicability of the fiber was evaluated through the extraction of some aromatic pollutants as model compounds from the headspace of aqueous samples in combination with gas chromatography and mass spectrometry. The parameters affecting the structure and extraction efficiency of the fiber (including the type of solvent, time, and potential for electrophoretic deposition) and the parameters affecting the extraction efficiency (such as coating type, salt content, extraction temperature, and time) were investigated. The results showed that the film thickness will be increased by increasing the potential and time duration. Finally, the characterization of the deposited film was accomplished by scanning electron microscopy and thermogravimetric analysis. After the optimization of the extraction parameters, the limit of detection of less than 20 pg/mL was achieved, and the calibration curves were all linear (r2  ≥ 0.9737), in the range from 50 to 500 pg/mL. The solid-phase microextraction fiber has a high mechanical strength; good stability and long service life, making it potentially applicable in the extraction of trace polycyclic aromatic hydrocarbons from aqueous samples.

Evaluation of Graphene as a Solid-Phase Extraction Sorbent for the Preconcentration and Determination of Trace Amounts of Nickel in Food Samples Prior to Flame Atomic Absorption Spectrometry.

A sensitive and low cost SPE method for the extraction, preconcentration, and flame atomic absorption spectrometric determination of nickel at ng/mL levels is described. Parameters governing the extraction efficiency including pH of the solution, eluent type, sample volume, and matrix ions were investigated for optimization of the presented procedure. The enhancement factor was calculated as 96.5. The calibration curve was linear with R2 of 0.999 in the concentration range from 2 to 200 ng/mL. The RSD was 5.35% (n=7), the LOD was 0.588 ng/mL, and relative recoveries from vegetable samples ranged between 99 and 109.5%.

The neuroendocrine phenotype of gastric myofibroblasts and its loss with cancer progression.

Stromal cells influence cancer progression. Myofibroblasts are an important stromal cell type, which influence the tumour microenvironment by release of extracellular matrix (ECM) proteins, proteases, cytokines and chemokines. The mechanisms of secretion are poorly understood. Here, we describe the secretion of marker proteins in gastric cancer and control myofibroblasts in response to insulin-like growth factor (IGF) stimulation and, using functional genomic approaches, we identify proteins influencing the secretory response. IGF rapidly increased myofibroblast secretion of an ECM protein, TGFßig-h3. The secretory response was not blocked by inhibition of protein synthesis and was partially mediated by increased intracellular calcium (Ca(2+)). The capacity for evoked secretion was associated with the presence of dense-core secretory vesicles and was lost in cells from patients with advanced gastric cancer. In cells responding to IGF-II, the expression of neuroendocrine marker proteins, including secretogranin-II and proenkephalin, was identified by gene array and LC-MS/MS respectively, and verified experimentally. The expression of proenkephalin was decreased in cancers from patients with advanced disease. Inhibition of secretogranin-II expression decreased the secretory response to IGF, and its over-expression recovered the secretory response consistent with a role in secretory vesicle biogenesis. We conclude that normal and some gastric cancer myofibroblasts have a neuroendocrine-like phenotype characterized by Ca(2+)-dependent regulated secretion, dense-core secretory vesicles and expression of neuroendocrine marker proteins; loss of the phenotype is associated with advanced cancer. A failure to regulate myofibroblast protein secretion may contribute to cancer progression.

A shutoff and exonuclease mutant of murine gammaherpesvirus-68 yields infectious virus and causes RNA loss in type I interferon receptor knockout cells.

Significant loss of RNA followed by severely reduced cellular protein pool, a phenomenon termed host shutoff, is associated with a number of lytic virus infections and is a critical player in viral pathogenesis. Until recently, viral DNA exonucleases were associated only with processing of viral genomic DNA and its encapsidation. However, recent observations have identified host shutoff and exonuclease function for the highly conserved viral exonucleases in γ-herpesviruses, which include Kaposi's sarcoma-associated herpesvirus, Epstein-Barr virus and the mouse model murine gammaherpesvirus-68, also referred to as MHV-68. In this study, we show that although ablation of the MHV-68 exonuclease ORF37 caused a restrictive phenotype in WT IFN-α/ß receptor-positive cells such as NIH 3T3, lack of ORF37 was tolerated in cells lacking the IFN-α/ß receptor: the ORF37Stop virus was capable of forming infectious particles and caused loss of mRNA in IFN-α/ß receptor knockout cells. Moreover, ORF37Stop virus was able to establish lytic infection in the lungs of mice lacking the IFN-α/ß receptor. These observations provide evidence that lytic MHV-68 infection and subsequent loss of mRNA can take place independently of ORF37. Moreover, efficient growth of ORF37Stop virus also identifies a role for this family of viral nucleases in providing a window of opportunity for virus growth by overcoming type I IFN-dependent responses.

The gene expression signature associated with TP53 mutation/deletion in chronic lymphocytic leukaemia is dominated by the under-expression of TP53 and other genes on chromosome 17p.

In chronic lymphocytic leukaemia (CLL), TP53 mutation and deletion are strongly associated with one another and with adverse clinical outcome. Mutant TP53 protein typically accumulates to high levels and has been reported to have transcriptional regulatory activity distinct from that of wild-type TP53. To investigate whether such an effect is relevant to CLL, carefully balanced primary CLL samples with or without TP53 mutation/deletion were compared for their gene expression profiles using high-density DNA microarrays. Ninety-six and eight differentially expressed genes were identified, respectively, using two alternative statistical approaches with different stringencies. None of the differentially expressed genes were known to be regulated by mutant TP53, and only four of the 67 under-expressed genes were known transcriptional targets of wild-type TP53. Significantly, both approaches showed that gene under-expression was the dominant feature of TP53-mutant CLL samples. Furthermore, a disproportionate number of the under-expressed genes were located on chromosome 17p, the most significant being TP53 itself. Together, these results indicate that any transcriptional regulatory effects of mutant TP53 in CLL cells are overshadowed by the under-expression of co-deleted TP53 and other genes on chromosome 17p. Our findings have implications for emerging therapeutic strategies that target mutant TP53.

Crystal structure of a KSHV-SOX-DNA complex: insights into the molecular mechanisms underlying DNase activity and host shutoff.

The early lytic phase of Kaposi's sarcoma herpesvirus infection is characterized by viral replication and the global degradation (shutoff) of host mRNA. Key to both activities is the virally encoded alkaline exonuclease KSHV SOX. While the DNase activity of KSHV SOX is required for the resolution of viral genomic DNA as a precursor to encapsidation, its exact involvement in host shutoff remains to be determined. We present the first crystal structure of a KSHV SOX-DNA complex that has illuminated the catalytic mechanism underpinning both its endo and exonuclease activities. We further illustrate that KSHV SOX, similar to its Epstein-Barr virus homologue, has an intrinsic RNase activity in vitro that although an element of host shutoff, cannot solely account for the phenomenon.

Human cytomegalovirus transcriptome activity differs during replication in human fibroblast, epithelial and astrocyte cell lines.

Broad cell tropism contributes to the pathogenesis of human cytomegalovirus (HCMV), but the extent to which cell type influences HCMV gene expression is unclear. A bespoke HCMV DNA microarray was used to monitor the transcriptome activity of the low passage Merlin strain of HCMV at 12, 24, 48 and 72 h post-infection, during a single round of replication in human fetal foreskin fibroblast cells (HFFF-2s), human retinal pigmented epithelial cells (RPE-1s) and human astrocytoma cells (U373MGs). In order to correlate transcriptome activity with concurrent biological responses, viral cytopathic effect, growth kinetics and genomic loads were examined in the three cell types. The temporal expression pattern of viral genes was broadly similar in HFFF-2s and RPE-1s, but dramatically different in U373MGs. Of the 165 known HCMV protein-coding genes, 41 and 48 were differentially regulated in RPE-1s and U373MGs, respectively, compared with HFFF-2s, and 22 of these were differentially regulated in both RPE-1s and U373MGs. In RPE-1s, all differentially regulated genes were downregulated, but, in U373MGs, some were down- and others upregulated. Differentially regulated genes were identified among the immediate-early, early, early late and true-late viral gene classes. Grouping of downregulated genes according to function at landmark stages of the replication cycle led to the identification of potential bottleneck stages (genome replication, virion assembly, and virion maturation and release) that may account for cell type-dependent viral growth kinetics. The possibility that cell type-specific differences in expressed cellular factors are responsible for modulation of viral gene expression is discussed.

High-Risk Behaviors and Associated Factors among Iranian Adult Population: A National Survey.

Background: There is no official and representative information on certain health-risk behaviors in Iran. This national survey was performed to determine the prevalence of five high-risk behaviors among the adult population and underlying factors. Methods: This cross-sectional study was performed in 23 provinces of Iran in 2019 involving 10,957 participants. The following five risky behaviors were evaluated: (a) using illicit drugs in the past month, (b) drinking alcohol in the past month, (c) having extramarital sex in the past year, (d) having suicidal thoughts in the past month, (e) and attempting suicide in the past year. The logistic regression model was used for analyses and associations were reported using odds ratio (OR) with its 95% confidence interval (CI). Results: The prevalence of health-risk behaviors was as follows: illicit drug use 10.4%, drinking alcohol 16.8%, extramarital sex 9.9%, suicidal thoughts 8.8%, and suicide attempt 5.4%. Almost 27.6% of the participants were involved in at least one risky behavior. There was a strong association between illicit drugs use and male gender 2.51 (2.11-2.98) and using psychiatric medications 2.96 (2.46-3.55); between drinking alcohol and male gender 2.23 (1.93-2.58); between extramarital sex and divorced/widowed status 2.43 (1.72-3.44) and having an intimate friend of the opposite sex 3.75 (3.13-4.51); between suicidal thoughts and using psychiatric medications 2.23 (1.83-2.72); between suicide attempt and a history of running away from home 2.10 (1.64-2.68). Conclusion: More than one-fourth Iranian adult population is involved in at least one risky behavior. Engaging in any risky behavior may increase the possibility of engaging in other high-risk behaviors.

The Epidemiology of Aggression and Associated Factors among Iranian Adult Population: A National Survey.

BACKGROUND: This survey was conducted to determine the level of aggression among the Iranian adult population and underlying predisposing factors. STUDY DESIGN: A cross-sectional study. METHODS: This cross-sectional study included 10,957 participants, involving 23 out of the 31 provinces of Iran in 2019. The outcome of interest was aggression, evaluated by the Buss & Perry aggression questionnaire. The association between aggression and 34 demographic, behavioral, social, and cultural characteristics was assessed using simple and multiple linear regression. RESULTS: The overall mean (SD) score of aggression was 77.10 (22.53). Based on the severity of aggression, the participants were categorized into four groups as follows: 2,464 (23.1%) nonaggressive, 4,692 (43.9%) mild, 3,071 (28.8%) moderate, and 454 (4.2%) severe aggressive. Aggression was more likely to occur in people with the following characteristics: younger ages, having several siblings, lower ranks of birth, having an intimate friend of the opposite sex, having an aggressive father/mother, history of parental divorce, interest in watching action/porn movies, listening to music, history of escape from home/school, using neuropsychiatric drugs, using illicit drugs, history of suicidal thoughts/attempt, and family conflict and hostility. Aggression was less likely to occur with the following characteristics: reading, regular physical exercise, the ability to control anger, regular prayer, adherence to avoid lying, respect to other people's rights, sexual satisfaction, and attachment to parents. CONCLUSION: A majority of the population has some degree of aggression. Aggression is a multifactorial behavior corresponding with several demographical, social, cultural, and religious factors, some of which back to early childhood events.

Murine gammaherpesvirus-induced fibrosis is associated with the development of alternatively activated macrophages.

Murine gammaherpesvirus 68 (MHV-68) is a natural pathogen of rodents closely related to the human gammaherpesviruses Kaposi's sarcoma-associated herpesvirus and EBV. Following intranasal infection, the virus replicates in the lung epithelium prior to establishing latent infection in lymphoid tissue. Infection of mice deficient in IFN-gammaR signaling (IFN-gammaR-/-) results in a multiple organ fibrosis, in which the spleen is severely affected. We show here that by Day 12 postinfection, prior to development of fibrosis in the spleens of IFN-gammaR-/- mice, different subsets of splenic macrophages (Mvarphis) are morphologically activated and enter latently infected germinal centers (GCs). Mvarphis coexpressing arginase I (ARG1), a marker of alternative activation of Mvarphis, and murine Mvarphi markers F4/80, ER-TR9, and MOMA-1 are found in GCs of IFN-gammaR-/- mice but not of wild-type mice. Quantitative RT-PCR of spleen RNA confirms induction of ARG1 and in addition, shows up-regulation of found in inflammatory zone 1/resistin-like molecule-alpha, tissue inhibitor of metalloproteinase-1, matrix metalloproteinase-12, fibronectin, and factor XIIIA in IFN-gammaR-/- mice. In contrast, inducible NO synthase, associated with classical Mvarphi activation, is up-regulated following infection of wild-type mice but not IFN-gammaR(-/-) mice. Concomitant with the aaMvarphis, transcription of the Th2 cytokines IL-13, IL-21, and IL-5 is up-regulated. Thus, in the absence of IFN-gammaR signaling, MHV-68 initiates a Th2 immune response, leading to alternative activation of macrophages and induction of fibrosis. This system provides an important model for studying the pathogenesis of fibrosis initiated by a latent herpesvirus infection.

Enhanced inhibition of influenza virus infection by peptide-noble-metal nanoparticle conjugates.

The influenza ("flu") type-A virus is a major medical and veterinary health concern and causes global pandemics. The peptide "FluPep" is an established inhibitor of influenza virus infectivity in model systems. We have explored the potential for noble-metal nanoparticle conjugates of FluPep to enhance its antiviral activity and to determine their potential as a delivery platform for FluPep. FluPep ligand is FluPep extended at its N-terminus with the sequence CVVVTAAA, to allow for its incorporation into a mixed-matrix ligand shell of a peptidol and an alkanethiol ethylene glycol consisting of 70% CVVVTol and 30% HS(CH2)11(OC2H4)4OH (mol/mol). Gold and silver nanoparticles (ca. 10 nm diameter) with up to 5% (mol/mol) FluPep ligand remained as stable as the control of mixed-matrix-passivated nanoparticles in a variety of tests, including ligand exchange with dithiothreitol. The free FluPep ligand peptide was found to inhibit viral plaque formation in canine MDCK cells (IC50 = 2.1 nM), but was less potent than FluPep itself (IC50 = 140 pM). Nanoparticles functionalised with FluPep ligand showed enhanced antiviral activity compared to the free peptides. The IC50 value of the FluPep-functionalised nanoparticles decreased as the grafting density of FluPep ligand increased from 0.03% to 5% (both mol/mol), with IC50 values down to about 10% of that of the corresponding free peptide. The data demonstrate that conjugation of FluPep to gold and silver nanoparticles enhances its antiviral potency; the antimicrobial activity of silver ions may enable the design of even more potent antimicrobial inhibitors, capable of targeting both influenza and bacterial co-infections.

Modified Activated Carbon Prepared from Acorn Shells as a New Solid-Phase Extraction Sorbent for the Preconcentration and Determination of Trace Amounts of Nickel in Food Samples Prior to Flame Atomic Absorption Spectrometry.

A new solid-phase extraction (SPE) sorbent was introduced based on acidic-modified (AM) activated carbon (AC) prepared from acorn shells of native oak trees in Kurdistan. Hydrochloric acid (15%, w/w) and nitric acid (32.5%, w/w) were used to condition and modify AC. The IR spectra of AC and AM-AC showed that AM lead to the formation of increasing numbers of acidic functional groups on AM-AC. AM-AC was used in the SPE method for the extraction and preconcentration of Ni+2 prior to flame atomic absorption spectrometric determination at ng/mL levels in model and real food samples. Effective parameters of the SPE procedure, such as the pH of the solutions, sorbent dosage, extraction time, sample volume, type of eluent, and matrix ions, were considered and optimized. An enrichment factor of 140 was obtained. The calibration curve was linear with an R2 of 0.997 in the concentration range of 1-220 ng/mL. The RSD was 5.67% (for n = 7), the LOD was 0.352 ng/mL, and relative recoveries in vegetable samples ranged from 96.7 to 103.7%.

Regulation of ecdysteroid signalling during Drosophila development: identification, characterization and modelling of ecdysone oxidase, an enzyme involved in control of ligand concentration.

The steroidal moulting hormones (ecdysteroids) mediate developmental transitions in insects, and their regulation is mainly controlled by the production and inactivation of these steroid hormones at the appropriate developmental times. One route of metabolism of ecdysteroids in insects involves EO (ecdysone oxidase)-catalysed conversion into 3-dehydroecdysteroid, which undergoes reduction to the corresponding 3-epiecdysteroid. By a twin-stranded bioinformatics approach, employing both phylogenomics and model structure-based analysis, we first predicted that DmEO (the EO of Drosophila melanogaster) corresponds to the protein product of gene CG9504. When CG9504 was expressed in COS7 cells, significant conversion of ecdysone into 3-dehydroecdysone was observed. Quantitative PCR and enzyme assay showed that DmEO was mainly expressed in the midgut during the late instars at a time corresponding to a hormone titre peak. DmEO shares only 27% amino acid sequence identity with Spodoptera littoralis (Lepidoptera) EO, yet key substrate-binding residues are well conserved. A model of DmEO is consistent with an inability to catalyse reaction of cholesterol derivatives. The significance of DmEO in ligand activation is discussed in relation to new evidence suggesting that 3-dehydro- and 3-epiecdysteroids may be functionally active as ligands in a novel, atypical ecdysteroid signalling pathway involving the Drosophila orphan nuclear receptor, DHR38, rather than being merely hormone inactivation products.

Evaluation of a new method for chemical coating of aluminum wire with molecularly imprinted polymer layer. Application for the fabrication of triazines selective solid-phase microextraction fiber.

A new solid-phase microextraction (SPME) fiber is fabricated through ultra violet irradiation polymerization of ametryn-molecularly imprinted polymer on the surface of anodized-silylated aluminum wire. The prepared fiber is durable with very good chemical and thermal stability which can be coupled to GC and GC/MS. The effective parameters on the fabrication and application procedures such as spraying mode, ultra violet irradiation (polymerization) time, number of sprayings and polymerizations, pH and ionic strength of sample and extraction time were optimized. This fiber shows high selectivity with great extraction capacity toward triazines. SPME and GC analysis of ametryn, prometryn, terbutryn, atrazine, simazine, propazine and cyanazine using the fabricated fiber result in the detection limits of 9, 32, 27, 43, 51, 74 and 85 ng mL(-1), respectively. The reliability of the prepared fiber in real samples has been investigated and proved by using spiked tap water, rice, maize and onion samples.

Preparation and binding study of solid-phase microextraction fiber on the basis of ametryn-imprinted polymer: application to the selective extraction of persistent triazine herbicides in tap water, rice, maize and onion.

A monolithic ametryn molecular-imprinted polymer based on a simple polymerization method was fabricated for use as new solid-phase microextraction (SPME) fiber, which can be coupled with GC and GC/MS for selective extraction and analysis of triazine herbicides. Methacrylic acid (MAA), ethylene glycol dimethacrylate (EDMA) and ametryn bear role of functional monomer, cross-linker and template, respectively. In the optimized conditions the fabricated fiber showed better molecular recognition abilities for methylthiotriazine herbicides than chloro-triazine herbicides. By use of bi-Langmuir isotherm model the evaluated equilibrium constants for ametryn were 0.01 and 890.69 microM(-1), and the numbers of binding sites were 129.98 and 5.82 nmol g(-1), respectively. The high extraction efficiency was obtained for ametryn, prometryn, terbutryn, atrazine, simazine, propazine, and cyanazine, yielding the detection limits of 14, 28, 45, 56, 85, 95 and 74 ng mL(-1), respectively by GC with flame ionization detection. The reliability of the prepared fiber for extraction of ametryn and other analogues in real samples has been investigated and proved by using spiked samples such as tap water, rice, maize, and onion.

Preparation of new solid phase micro extraction fiber on the basis of atrazine-molecular imprinted polymer: application for GC and GC/MS screening of triazine herbicides in water, rice and onion.

A simple polymerization strategy has been used to produce a monolithic solid phase micro extraction (SPME) fiber on the basis of molecularly imprinted polymer able to couple with GC and GC-MS for selective extraction and analysis of triazine herbicides. A fiber was produced by copolymerization of methacrylic acid-ethylene glycol dimethacrylate imprinted with atrazine. The effective factors influencing the polymerization have been investigated and are detailed here. At the optimum conditions the prepared fiber is firm, inexpensive, durable and thermally stable up to 280 degrees C which has vital importance in SPME coupled with GC or GC/MS. In addition, the influences of pH, extraction time and temperature on the extraction efficiency of analytes were optimized. Selectivity of prepared fibers in relation to triazine herbicides and some of the other pesticide has been investigated. The high extraction efficiency was obtained for atrazine, simazine, propazine, cyanazine, ametryn, terbutryn and prometryn yielding the detection limits of 20, 70, 80, 81, 69, 88 and 68 ng mL(-1), respectively and the high quantities of recoveries. The reliability of prepared fiber to extraction of atrazine and other analogues in real samples has been investigated and proved by implementation of SPME in spiked samples such as tap water, onion and rice.

Severe respiratory syncytial virus bronchiolitis in infants is associated with reduced airway interferon gamma and substance P.

BACKGROUND: Severe human respiratory syncytial virus (hRSV) bronchiolitis in previously well infants may be due to differences in the innate immune response to hRSV infection. AIM: to determine if factors mediating proposed mechanisms for severe bronchiolitis differ with severity of disease. METHODOLOGY/PRINCIPLE FINDINGS: 197 infants admitted to hospital with hRSV bronchiolitis were recruited and grouped according to no oxygen requirement (n = 27), oxygen dependence (n = 114) or mechanical ventilation (n = 56). We collected clinical data, nasopharyngeal aspirate (NPA) and if ventilated bronchoalveolar lavage (BAL). Interferon-gamma (IFN-gamma), substance P (SP), interleukin 9 (IL-9), urea and hRSV load, were measured in cell free supernatant from NPA and BAL. Multivariate analysis compared independent effects of clinical, virological and immunological variables upon disease severity. IFN-gamma and SP concentrations were lower in NPA from infants who required oxygen or mechanical ventilation. Viral load and IL-9 concentrations were high but did not vary with severity of disease. Independent predictors of severe disease (in diminishing size of effect) were low weight on admission, low gestation at birth, low NPA IFN-gamma and NPA SP. Nasal airway sampling appears to be a useful surrogate for distal airway sampling since concentrations of IFN-gamma, SP, IL-9 and viral load in NPA correlate with the same in BAL. CONCLUSIONS: Our data support two proposed mechanisms for severe hRSV disease; reduced local IFN-gamma response and SP mediated inflammation. We found large amounts of hRSV and IL-9 in airways secretions from the upper and lower respiratory tract but could not associate these with disease severity.