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1.
BACKGROUND: Preceding mucosal response to one allergen leads to the priming of the nasal mucosal response to another allergen. This study aimed to determine whether environmental allergens, especially ubiquitous animal dander, can induce nasal priming. METHODS: We investigated 26 grass-pollen-allergic subjects with additional sensitization to other aeroallergens. We performed continuous allergen challenge for 2 h with 1500 Dactylis glomerata pollen/m3 in the Vienna challenge chamber. The nasal flow at 150 Pa was examined, and subjective scores were obtained every 15 min. Statistical analysis was calculated from the area under curve of nasal flow reduction by Student's t-test and the Mann-Whitney U-test. Alpha was 0.05. RESULTS: In subjects with positive cat-dander RAST (class of > or = 3), besides grass-pollen allergy, the specific nasal allergic reaction to Dactylis challenge was significantly pronounced (P < 0.01), and an earlier onset of reaction was evident. The same results were obtained with additional sensitization to dog dander (P < 0.05). Concomitant sensitization to mugwort also led to escalating symptoms (P < 0.05). CONCLUSIONS: These results indicate that a specific nasal allergic reaction is augmented by environmental priming caused by ubiquitous animal dander and possibly is influenced by the daily use of spices.  相似文献   
2.
This paper reports the fabrication and characterization of a prototype microfluidic device that can act as a periodic beam steerer. The prototype is formed by a simple T-junction followed by a serpentine channel that allows generation of a periodical segmented flow of air and water bubbles. If light hits the channel wall with a suitable angle, it can be either transmitted or reflected by the segmented flow, giving rise to an alternating beam steerer. The duty cycle, switching frequency, and overall stability and reproducibility of this prototype system are presented and discussed.  相似文献   
3.
Background: Chlamydia trachomatis (CT) is the agent of the most common bacterial sexually transmitted infection worldwide. Until now, little information is available about the microbial composition of urine samples during CT urethritis. Therefore, in this study, we characterized the microbiome and metabolome profiles of first-void urines in a cohort of women with CT urethral infection attending an STI clinic. Methods: Based on CT positivity by nucleic acid amplification techniques on urine samples, the enrolled women were divided into two groups, i.e., “CT-negative” (n = 21) and “CT-positive” (n = 11). Urine samples were employed for (i) the microbiome profile analysis by means of 16s rRNA gene sequencing and (ii) the metabolome analysis by 1H-NMR. Results: Irrespective of CT infection, the microbiome of first-void urines was mainly dominated by Lactobacillus, L. iners and L. crispatus being the most represented species. CT-positive samples were characterized by reduced microbial biodiversity compared to the controls. Moreover, a significant reduction of the Mycoplasmataceae family—in particular, of the Ureaplasma parvum species—was observed during CT infection. The Chlamydia genus was positively correlated with urine hippurate and lactulose. Conclusions: These data can help elucidate the pathogenesis of chlamydial urogenital infections, as well as to set up innovative diagnostic and therapeutic approaches.  相似文献   
4.
Maize stovers collected every 14 days over an 84-day growth period were subjected to high-performance liquid chromatography with electrochemical detector (HPLC-ED) and pyrolysis/gas chromatography/mass spectrometry (PY/GC/MS) in order to monitor changes in the phenolic composition. Prior to HPLC-ED analyses, ground samples were sequentially extracted with (i) methanol, (ii) 0·1M sodium hydroxide and (iii) 2M sodium hydroxide in the presence of nitrobenzene to separate, respectively, free phenolic monomers, alkali-labile phenolic monomers and alkali-resistant lignin. In turn, solution (ii) was treated with alkaline nitrobenzene to obtain (iv) alkali-labile lignin. Pyrolysis was carried out on ground native samples by using a platinum heated filament pyrolyser. Increases in the absolute phenolic concentrations in the residues of 0·1M sodium hydroxide extraction and in the ratio of alkali-resistant lignin vs total lignin were observed by HPLC-ED during the first 28–42 days of maturation, reaching a steady level in the remaining maturation period. A linear increase of syringyl units vs guaiacyl units was for found the alkali-resistant lignin fraction over the entire period of maturation. Similar trends were showed by PY/GC/MS with regard to relative lignin content and syringyl/guaiacyl ratio. Both techniques showed their usefulness to gauge changes in the phenolic composition during the lignification process.  相似文献   
5.
Background: Enzymes of tricarboxylic acid (TCA) have recently been recognized as tumor suppressors. Mutations in the SDHB subunit of succinate dehydrogenase (SDH) cause pheochromocytomas and paragangliomas (PCCs/PGLs) and predispose patients to malignant disease with poor prognosis. Methods: Using the human pheochromocytoma cell line (hPheo1), we knocked down SDHB gene expression using CRISPR-cas9 technology. Results: Microarray gene expression analysis showed that >500 differentially expressed gene targets, about 54%, were upregulated in response to SDHB knock down. Notably, genes involved in glycolysis, hypoxia, cell proliferation, and cell differentiation were up regulated, whereas genes involved in oxidative phosphorylation (OXPHOS) were downregulated. In vitro studies show that hPheo1 proliferation is not affected negatively and the cells that survive by shifting their metabolism to the use of glutamine as an alternative energy source and promote OXPHOS activity. Knock down of SDHB expression results in a significant increase in GLUD1 expression in hPheo1 cells cultured as monolayer or as 3D culture. Analysis of TCGA data confirms the enhancement of GLUD1 in SDHB mutated/low expressed PCCs/PGLs. Conclusions: Our data suggest that the downregulation of SDHB in PCCs/PGLs results in increased GLUD1 expression and may represent a potential biomarker and therapeutic target in SDHB mutated tumors and SDHB loss of activity-dependent diseases.  相似文献   
6.
Introduction: A reliable method of intradialysis calcium mass balance quantification is far from been established. We herein investigated the use of a single‐pool variable‐volume Calcium kinetic model to assess calcium mass balance in chronic and stable dialysis patients. Methods: Thirty‐four patients on thrice‐weekly HD were studied during 240 dialysis sessions. All patients were dialyzed with a nominal total calcium concentration of 1.50 mmol/L. The main assumption of the model is that the calcium distribution volume is equal to the extracellular volume during dialysis. This hypothesis is assumed valid if measured and predicted end dialysis plasma water ionized calcium concentrations are equal. A difference between predicted and measured end‐dialysis ionized plasma water calcium concentration is a deviation on our main hypothesis, meaning that a substantial amount of calcium is exchanged between the extracellular volume and a nonmodeled compartment. Findings: The difference between predicted and measured values was 0.02 mmol/L (range ?0.08:0.16 mmol/L). With a mean ionized dialysate calcium concentration of 1.25 mmol/L, calcium mass balance was on average negative (mean ± SD ?0.84 ± 1.33 mmol, range ?5.42:2.75). Predialysis ionized plasma water concentration and total ultrafiltrate were the most important predictors of calcium mass balance. A significant mobilization of calcium from the extracellular pool to a nonmodeled pool was calculated in a group of patients. Discussion: The proposed single pool variable‐volume Calcium kinetic model is adequate for prediction and quantification of intradialysis calcium mass balance, it can evaluate the eventual calcium transfer outside the extracellular pool in clinical practice.  相似文献   
7.
8.
Hexachlorocyclohexanes in the North American atmosphere   总被引:2,自引:0,他引:2  
Annually integrated air concentrations of alpha- and gamma-hexachlorocyclohexane (HCH) were determined in 2000/2001 at 40 stations across North America using XAD-based passive air samplers to understand atmospheric distribution processes on a continental scale. Elevated levels of gamma-HCH in the atmosphere of the Canadian Prairies are consistent with the ongoing use of lindane as a seed treatment on canola and confirm the feasibility of detecting the agricultural use of a pesticide using long-term integrated passive air sampling. In contrast to gamma-HCH, the atmospheric concentrations of alpha-HCH show a rather uniform distribution across Canada and the United States, which is expected for a chemical with no current use on the continent. Higher levels in the atmosphere over Atlantic Canada can be explained by alpha-HCH evaporating from the waters of the Labrador Current, which is supported bythe chiral composition of alpha-HCH and the temperature dependence of its atmospheric concentrations along the east coast of Canada. Similarly, alpha-HCH is volatilizing from Lake Superior. Atmospheric HCH levels increase with elevation in the Canadian Rocky Mountains. The results suggest that evaporation, in particular from cold water bodies, is an important source of alpha-HCH to the North American atmosphere. Low levels of HCHs in Central America hint at efficient degradation under tropical conditions. Chiral analysis shows that (+)-alpha-HCH is often enriched in air over continental areas and at the Pacific Coast, which is opposite to the enantiomeric enrichment in the proximity to the Great Lakes and the Atlantic Ocean. Passive air sampling is a powerful tool to discern the large-scale variability of semivolatile and persistent organic chemicals in the atmosphere.  相似文献   
9.
A novel setup for the coupling of a commercially available thin-layer cell to electrospray mass spectrometry (ESI-MS) which allows the electrochemical reactions at the counter electrode to be straightforwardly separated from the flow into the mass spectrometer has been developed. In this way, interferences from reaction products formed at the counter electrode can be minimized. This reduces the risk of changes in the mass spectra as a result of electrochemical reactions in the solution. The described setup also enables the working electrode to be positioned close to the electrospray (ESI) emitter without the need for a grounding point or a long transfer line between the electrochemical cell and the electrospray emitter. By decoupling the electrochemical reactions in the flow cell and those in the electrospray emitter, improved facilities for studies of electrochemical reactions are obtained through a better control of the potential of the working electrode. The setup has been used to study the oxidation of a drug (Olsalazine), which previously has been found to involve chemical follow-up reactions. It is also demonstrated that uncharged thiols can be detected in ESI-MS after spontaneous adsorption on a gold working electrode, followed by oxidative desorption to yield sulfinates or sulfonates. This adsorption and potential-controlled desorption has been used for the preconcentration of micromolar concentrations of 1-hexanethiol as well as for desalting of solutions containing micromolar concentrations of thiols. The results indicate that the present on-line coupling of an electrochemical cell to ESI-MS provides promising possibilities for sample preconcentration, matrix exchange (including desalting), and ionization of neutral compounds, such as thiols.  相似文献   
10.
Vestibular Deiters' neurons have been isolated from bovine brain by the Hydén's freehand dissection technique and challenged with monoclonal antibodies directed toward the alpha 1 and beta 2/3 subunits of the GABAA receptors. Subsequent challenge with fluorescent secondary antibodies and confocal microscopy allowed the study of the cellular distribution of such subunits. In Deiters' neurons the beta 2/3 subunit displayed a clear presence all along the cell body profile and the initial parts of the dendrites. The alpha 1 subunit was found highly present all over the cell interior except the nuclear profiles. The strong presence inside the cells possibly masked its presence on the plasma membrane. However, in part of the cells studied a distinct presence on the plasma membrane was evident. This subunit was visualized also all along the long dendrites of these neurons. The approach we describe here, involving freehand isolated mature neurons from adult animals, may allow a better characterization of the tridimensional distribution of different types of neuronal GABAA receptors in the respect of the approach with brain slices.  相似文献   
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