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Phase Reaction (phase + reaction)
Kinds of Phase Reaction Selected AbstractsAcute phase reaction in the fetus and newbornACTA PAEDIATRICA, Issue 9 2000R Bracci First page of article [source] The birth process initiates an acute phase reaction in the fetus-newborn infantACTA PAEDIATRICA, Issue 9 2000G Marchini Our goal was to investigate whether the normal birth process stimulated an acute phase response in healthy infants with physiological changes in the circulating levels of acute phase cytokines and acute phase proteins. We also monitored body temperature, body weight and behavioural state in order to investigate if clinical signs of acute phase reaction were present. We made cross-sectional measurements of interleukin-1,, interleukin-6, C-reactive protein, serum amyloid A, procalcitonin, prealbumin, body weight, body temperature and the duration of the sleeping period during the first four postnatal days. We found an increase in interleukin-6 (p < 0.001) during the first day, followed by an increase in C-reactive protein, serum amyloid A and procalcitonin on the second postnatal day (p < 0.01). The level of prealbumin fell after birth and reached its lowest value at 3 d of age (p < 0,001). Interleukin-l p remained unchanged. The duration of the sleeping period was longer during the first day (p < 0.01). There was an increase in body temperature during the first day (p < 0.01). Maximal weight loss was during the first 2 d. Conclusions: The normal birth process and extra-uterine adaptation stimulates an acute phase reaction in the newborn infant with a release of interleukin-6 and acute phase proteins and a depression of prealbumin. This reaction, as the body's first line inflammatory defence system, probably affects the infant's behaviour, nutritional state as well as the regulation of body temperature. [source] The PPAR, agonist GW501516 suppresses interleukin-6-mediated hepatocyte acute phase reaction via STAT3 inhibitionEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 5 2007T. Kino Abstract Background, Interleukin-6 and downstream liver effectors acute phase reactants are implicated in the systemic inflammatory reaction. Peroxisome proliferator-activated receptor , (PPAR,), which binds to and is activated by a variety of fatty acids, was recently shown to have anti-inflammatory actions. Materials and methods, We examined the ability of the synthetic PPAR, agonist GW501516 to suppress interleukin-6-induced expression of acute phase proteins in human hepatoma HepG2 cells and rat primary hepatocytes. Results, GW501516 dose-dependently suppressed interleukin-6-induced mRNA expression of the acute phase protein ,1-antichymotrypsin in HepG2 cells. The compound also suppressed interleukin-6-induced mRNA expression of ,2-acid glycoprotein, ,-fibrinogen and ,2-macroglobulin in and the secretion of C-reactive protein by rat primary hepatocytes. Depletion of the PPAR, receptor, but not of PPAR, or ,, attenuated the suppressive effect of GW501516 on interleukin-6-induced ,1-antichymotrypsin mRNA expression, indicating that PPAR, specifically mediated this effect. Since interleukin-6 stimulates the transcriptional activity of the ,1-antichymotrypsin promoter by activating the signal transducer and activator of transcription (STAT) 3, we examined functional interaction of this transcription factor and PPAR, on this promoter. Overexpression of PPAR, enhanced the suppressive effect of GW501516 on STAT3-activated transcriptional activity of the ,1-antichymotrypsin promoter, while GW501516 suppressed interleukin-6-induced binding of this transcription factor to this promoter. Conclusions, These findings indicate that agonist-activated PPAR, interferes with interleukin-6-induced acute phase reaction in the liver by inhibiting the transcriptional activity of STAT3. PPAR, agonists might be useful for the suppression of systemic inflammatory reactions in which IL-6 plays a central role. [source] Synthesis of Core,Shell Inorganic NanotubesADVANCED FUNCTIONAL MATERIALS, Issue 15 2010Ronen Kreizman Abstract New materials and techniques pertaining to the synthesis of inorganic nanotubes have been ever increasing since the initiation of the field in 1992. Recently, WS2 nanotubes, which are produced now in large amounts, were filled with molten lead iodide salt by a capillary wetting process, resulting in PbI2@WS2 core,shell nanotubes. This work features progress in the synthesis of new core,shell nanotubes, including BiI3@WS2 nanotubes produced in a similar same manner. In addition, two new techniques for obtaining core,shell nanotubes are presented. The first is via electron-beam irradiation, i.e., in situ synthesis within a transmission electron microscope. This synthesis results in SbI3 nanotubes, observed either in a hollow core of WS2 ones (SbI3@WS2 nanotubes), or atop of them (WS2@SbI3 nanotubes). The second technique involves a gaseous phase reaction, where the layered product employs WS2 nanotubes as nucleation sites. In this case, the MoS2 layers most often cover the WS2 nanotube, resulting in WS2@MoS2 core,shell nanotubes. Notably, superstructures of the form MoS2@WS2@MoS2 are occasionally obtained. Using a semi-empirical model, it is shown that the PbI2 nanotubes become stable within the core of MoS2 nanotubes only above a critical core diameter of the host (>12,nm); below this diameter the PbI2 crystallizes as nanowires. These model calculations are in agreement with the current experimental observations, providing further support to the growth mechanism of such core,shell nanotubes. [source] Kinetics of the sulfate radical-mediated photo-oxidation of humic substancesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 1 2008Pedro M. David Gara The kinetics of the aqueous phase reaction of sulfate radicals with commercial humic acids and with organic matter extracted from vermicompost (VC) was studied by flash-photolysis. The results can be interpreted by a mechanism that in a first step considers the reversible binding of the sulfate radicals by the humic substances. Both the bound and free sulfate radicals decay to oxidized products. From experiments performed with Aldrich humic acids in the temperature range from 283 to 303 K, the enthalpy change associated with the binding process was estimated to be ,(36 ± 11) kJ mol,1. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 40: 19,24, 2008 [source] Rate coefficients for the reaction of OH with OClO between 242 and 392 K,INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 4 2006Tomasz Gierczak Rate coefficients are reported for the gas phase reaction of OH with OClO over the temperature range 242,392 K at 25, 50, and 100 Torr (He). Kinetic measurements were made using pulsed laser photolysis with laser induced fluorescence detection of the OH radical. The measured rate coefficients were independent of pressure and are well represented by k1(T) = (1.43,±,0.3),×,10,12 exp(597,±,36/T) cm3 molecule,1 s,1 (k1(298 K) = 1.06,×,10,11 cm3 molecule,1 s,1). The quoted uncertainties are 2, (95% confidence level) and include estimated systematic errors. Discrepancies with the previous OH + OClO rate coefficient measurement by Poulet et al. (Int J Chem Kinet 1986, 18, 847,859) are discussed. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 234,241, 2006 [source] Side Effects of Cardiopulmonary Bypass:JOURNAL OF CARDIAC SURGERY, Issue 6 2004What Is the Reality? This is due, in part, to lack of suitable control group against which bypass and cardioplegic arrest can be compared. The recent success of beating heart coronary artery bypass grafting has, however, for the first time, provided an opportunity to compare the same operation, in similar patient groups, with, or without CPB and cardioplegic arrest. CPB is associated with an acute phase reaction of protease cascades, leucocyte, and platelet activation that result in tissue injury. This is largely manifest as subclinical organ dysfunction that produces a clinical effect in those patients that generate an excessive inflammatory response or in those with limited functional reserve. The contribution of myocardial ischemia/reperfusion, secondary to aortic cross-clamping, and cardioplegic arrest, to the systemic inflammatory response and wider organ dysfunction is unknown, and requires further evaluation in clinical trials. [source] Experimental study of feasibility in kinetically-controlled reactive distillationAICHE JOURNAL, Issue 2 2005Madhura Chiplunkar Abstract Bifurcation studies predict limited ranges of feasibility for products in certain reactive distillations. These are closely related to the bifurcations in the singular points of dynamic models for simple reactive distillation (isobaric open evaporation with liquid phase reaction). A new dynamic model is described with constant vapor rate together with an experimental study for the reactive distillation of acetic acid with isopropanol to produce isopropyl acetate, catalyzed by Amberlyst-15 ion-exchange resin. An experimental apparatus with real-time measurement of liquid compositions based on Fourier transform infrared (FTIR) spectroscopy is described, and used to follow the composition dynamics at several initial conditions and Damköhler numbers (Da). The experimental results match model predictions that show four regions of behavior. For Da , 1, these show a stable node at acetic acid and several other fixed points as saddles. However, near Da , 2, both isopropanol and acetic acid are stable nodes and a quaternary singular point appears. The presence of two stable nodes requires the presence of a distillation boundary and, therefore, a limited feasibility for the bottom product compositions from continuous reactive distillation. For the reaction rates studied, the model predictions are closely consistent with the experimental findings, and are robust to variations in the vapor rate. These experiments are among the first to analyze the dynamics and feasibility in a kinetically-controlled reactive distillation and are consistent with previous studies for the reaction equilibrium limit, indicating the formation of a reactive azeotrope. © 2005 American Institute of Chemical Engineers AIChE J, 51: 464,479, 2005 [source] Cholestatic liver disease: pathophysiology and therapeutic optionsLIVER INTERNATIONAL, Issue 2002AF. Hofmann Abstract: Cholestasis results from defective canalicular secretion of bile or obstruction to bile flow distal to the canaliculus. In early primary biliary cirrhosis, bile secretion continues, because of the secretory pressure of bile or because some ductules are not obstructed. With complete cholestasis, a bile acid deficiency occurs in the small intestinal lumen leading to lipid maldigestion and fat-soluble vitamin malabsorption. Bacterial proliferation, bacterial translocation to lymph nodes and endotoxemia may also occur leading to an acute phase reaction. Retention of bile acids in the hepatocyte leads to apoptosis. Accumulation of bile acids in the systemic circulation leads to pruritus, and may contribute to endothelial injury in the lungs and kidney. Early attempts to mimic hepatic excretory function by hemoperfusion over adsorbent columns were unsuccessful for a variety of reasons. Extracorporeal dialysis against albumin offers promise of a realistic albeit partial simulation of hepatic excretory function. [source] The decline of Steller sea lions Eumetopias jubatus in Alaska: a review of the nutritional stress hypothesisMAMMAL REVIEW, Issue 1 2003A. W. TRITES ABSTRACT 1.,The decline of Steller sea lions Eumetopias jubatus in the Gulf of Alaska and Aleutian Islands between the late 1970s and 1990s may have been related to reduced availability of suitable prey. Many studies have shown that pinnipeds and other mammals suffering from nutritional stress typically exhibit reduced body size, reduced productivity, high mortality of pups and juveniles, altered blood chemistry and specific behavioural modifications. 2.,Morphometric measurements of Steller sea lions through the 1970s and 1980s in Alaska indicate reduced body size. Reduced numbers of pups born and an apparent increase in juvenile mortality rates also appear to be nutritionally based. Blood chemistry analyses have further shown that Steller sea lions in the Gulf of Alaska and Aleutian Islands area exhibited signs of an acute phase reaction, or immune reaction, in response to unidentified physical and/or environmental stress. Behavioural studies during the 1990s have not noted any changes that are indicative of an overall shortage in the quantity of prey available to lactating female sea lions. 3.,The data collected in Alaska are consistent with the hypothesis that Steller sea lions in the declining regions were nutritionally compromised because of the relative quality of prey available to them (chronic nutritional stress), rather than because of the overall quantity of fish per se (acute nutritional stress). This is further supported by captive studies that indicate the overall quality of prey that has been available to Steller sea lions in the declining population could compromise the health of Steller sea lions and hinder their recovery. [source] Determination of Optimum Conditions and the Kinetics of Methanol OxidationCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 1 2010A. H. Ulukardesler Abstract In this study, the catalytic oxidation of methanol to formaldehyde was investigated in a laboratory-scale fixed-bed catalytic reactor, under a large number of different conditions. Iron-molybdate catalysts supported by silica or alumina with a molybdenium/iron (Mo/Fe) ratio of 1.5, 3 and 5 were studied for the gas phase reaction. In order to obtain the optimum conditions, six different temperatures in the range of 250,375,°C and three different space times of 50.63, 33.75 and 20.25 g/(mol/h) were investigated. After determining the optimum conditions for this reaction, experiments aimed at understanding the reaction kinetics, were carried out. These experiments were performed on the catalyst favoring the formation of formaldehyde, which has a (Mo/Fe) ratio of 5 on a silica support. Seven reaction models derived by the mechanisms cited in the literature were tested to elucidate the kinetics of the reaction and the surface reaction controlling model was found to be the most suitable reaction mechanism. [source] Study on Synthesis and Electrochemical Properties of Nanophase Li-Mn-spinelCHINESE JOURNAL OF CHEMISTRY, Issue 3 2003Feng Chuan-Qi Abstract Li-Mn-spinel was synthesized using the rheological phase reaction method. First, the precursor was prepared by rheological phase reaction. Then it was decomposed to form Li-Mn-spinel, which was characterized by X-ray diffraction analysis and IR spectra. The particle size of Li-Mn-spinel was determined by the method of the transmission electron microscopy. The synthesized materials are of nanometer size with 30,100 nm in the average diameter. The electrochemical properties of the Li-Mn-spinel were also studied. It proved that this method not only provided a simple practicable and effective route for the synthesis of Li-Mn-spinel, but also had many advantages such as lower sintering temperature, shorter sintering time, fine particles and particularly excellent electrochemical performances. [source] Endogenous glucocorticoids and antigen-induced acute and late phase pulmonary responsesCLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2000Stokes Peebles Background Several studies suggest that endogenous glucocorticoids can dampen the severity of experimental allergic reactions in animals. Objective To investigate the influence that endogenous glucocorticoids have on the course of IgE-mediated pulmonary early and late phase reactions. Methods Twenty-one allergic asthmatic and six healthy control subjects underwent inhaled antigen challenge with measurements of plasma cortisol and cortisone by gas chromatography-mass spectrometry. Results There were no differences between the asthmatic and control groups in the baseline levels of cortisol or cortisone. However, the asthmatic subjects had significantly higher cortisol levels (67.2 ± 8.6 vs 35.1 ± 4.5 ng/mL; P = 0.04) and had higher cortisol/cortisone ratios (4.8 ± 0.6 vs 3.0 ± 0.2; P = 0.01) 8 h after challenge compared to the control subjects. Among the asthmatic subjects, those whose FEV1 recovered rapidly had higher baseline levels of cortisol and those who displayed a late phase reaction had lower levels of cortisol during the late phase period. Conclusion The results suggest that endogenous glucocorticoids may play a significant role in the modulation of airway responses to antigen challenge, and that antigen challenge may induce cortisol production in allergic subjects. [source] A Microfluidic Approach to the Rapid Screening of Palladium-Catalysed Aminocarbonylation ReactionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 18 2009Philip Abstract The evaluation and selection of the most appropriate catalyst for a chemical transformation is an important process in many areas of synthetic chemistry. Conventional catalyst screening involving batch reactor systems can be both time-consuming and expensive, resulting in a large number of individual chemical reactions. Continuous flow microfluidic reactors are increasingly viewed as a powerful alternative format for reacting and processing larger numbers of small-scale reactions in a rapid, more controlled and safer fashion. In this study we demonstrate the use of a planar glass microfluidic reactor for performing the three-component palladium-catalysed aminocarbonylation reaction of iodobenzene, benzylamine and carbon monoxide to form N -benzylbenzamide, and screen a series of palladium catalysts over a range of temperatures. N -Benzylbenzamide product yields for this reaction were found to be highly dependent on the nature of the catalyst and reaction temperature. The majority of catalysts gave good to high yields under typical flow conditions at high temperatures (150,°C), however the palladium(II) chloride-Xantphos complex [PdCl2(Xantphos)] proved to be far superior as a catalyst at lower temperatures (75,120,°C). The utilised method was found to be an efficent and reliable way for screening a large number of palladium-catalysed carbonylation reactions and may prove useful in screening other gas/liquid phase reactions. [source] Reactions of gaseous ions.JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 1 2001Editor's Note: The following paper is the first in a series that describes the gas phase reactions of positive ions derived from compounds such as methane and ethylene with other gas phase molecules to produce secondary ions. These very careful experiments formed the basis of chemical ionization, one of the ionization techniques that revolutionized mass spectrometry at that time and a technique still very much in use today. At elevated pressures in a mass spectrometer ion source reactions occur between certain ions and the neutral species present. We have studied the various secondary ions formed in methane and ethylene at elevated pressures and have determined the reactions by which they are formed and the rates of these reactions. The rates are all extremely fast. The reaction rates have been treated by classical collision theory and it has been shown that to a fair approximation the cross-sections and reaction rate constants can be predicted from a simple balance of rotational and polarization forces. [Reprinted from J. Am. Chem. Soc. 1957; 79: 2419.] Copyright © 1957 by the American Chemical Society and reprinted by permission of the copyright owner. [source] Synthesis of Porous Silicon Nitride with Unidirectionally Aligned Channels Using Freeze-Drying ProcessJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2002Takayuki Fukasawa Porous silicon nitride with macroscopically aligned channels was synthesized using a freeze-drying process. Freezing of a water-based slurry of silicon nitride was done while unidirectionally controlling the growth direction of the ice. Pores were generated subsequently by sublimation of the columnar ice during freeze-drying. By sintering this green body, a porous silicon nitride with high porosity (over 50%) was obtained and its porosity was controllable by the slurry concentration. The porous Si3N4 had a unique microstructure, where macroscopically aligned open pores contained fibrous grains protruding from the internal walls of the Si3N4 matrix. It is hypothesized that vapor/solid phase reactions were important to the formation mechanism of the fibrous grains. [source] Microreactor Array Assembly, Designed for Diversity Oriented Synthesis Using a Multiple Core Structure Library on Solid SupportMOLECULAR INFORMATICS, Issue 11 2006Alexander Groß Abstract The application of spatially encoded principles in solid phase combinatorial synthesis requires no chemical or physical coding strategies. The resulting products are encoded by their position inside the array and their synthesis history. The advantages of microreactor arrays for solid phase synthesis as one of the embodiments in the field of microreaction technology are discussed. Here, we review the reactor design, necessary process steps, and a strategy for the diversity oriented array synthesis. In particular, the glass-made microreactor and its assembly for 1563 parallel solid phase reactions, which can be performed at temperatures up to 120,°C, are described. Bead loading and liquid handling steps were adapted to this array. The production of large libraries demands suitable synthesis protocols and building blocks. The optimization of appropriate synthesis conditions is a time-consuming process. A multiple core structure library approach for the efficient synthesis of diverse heterocyclic libraries is described. The aim of this work was to prove the feasibility of the glass-microreaction array for massive parallel library synthesis. [source] Reactions of Cl,/Cl2,, Radicals with the Nanoparticle Silica Surface and with Humic Acids: Model Reactions for the Aqueous Phase Chemistry of the AtmospherePHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007Paula Caregnato ABSTRACT Reactions of chlorine radicals might play a role in aqueous aerosols where a core of inorganic components containing insulators such as SiO2 and dissolved HUmic-LIke Substances (HULIS) are present. Herein, we report conventional flash photolysis experiments performed to investigate the aqueous phase reactions of silica nanoparticles (NP) and humic acid (HA) with chlorine atoms, Cl,, and dichloride radical anions, Cl2,,. Silica NP and HA may be taken as rough models for the inorganic core and HULIS contained in atmospheric particles, respectively. Both Cl, and Cl2,, were observed to react with the deprotonated silanols on the NP surface with reaction rate constants, k ± ,, of (9 ± 6) × 107 M,1 s,1 and (7 ± 4) × 105 M,1 s,1, respectively. The reaction of Cl, with the surface deprotonated silanols leads to the formation of SiO, defects. HA are also observed to react with Cl, and Cl2,, radicals, with reaction rate constants at pH 4 of (3 ± 2) × 1010 M,1 s,1 and (1.2 ± 0.3) × 109 M,1 s,1, respectively. The high values observed for these constants were discussed in terms of the multifunctional heterogeneous mixture of organic molecules conforming HA. [source] Numerical Calculations of Spray Roasting Reactors of the Steel Industry with Special Emphasis on Fe2O3 -Particle FormationCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2007M. Beck Abstract This work presents numerical calculations for the lay-out of spray roasting reactors for the steel industry. In these reactors, a pickling liquor based on water and HCl containing FeCl2 is regenerated in a combustor leading to the formation of Fe2O3 particles. For the lay-out of these reactors, detailed knowledge of the flow and temperature field, the associated gas phase reactions, and especially, of the formation of the Fe2O3 particles is required. An extended particle formation model is presented which is based on earlier work. Finally, results for an industrial spray roasting reactor are given showing the potential of the numerical tools developed for the improvement of the technical lay-out of such thermal reactors. [source] Solution- and Solid-Phase Synthesis of Radicicol (Monorden) and Pochonin CCHEMISTRY - A EUROPEAN JOURNAL, Issue 17 2005Sofia Barluenga Dr. Abstract A modular synthesis for pochonin C and radicicol is reported. The two natural products were prepared in seven and eight steps, respectively, from three readily available fragments. Alternative syntheses of these compounds were achieved using a combination of polymer-bound reagents and solid phase reactions. The conformation of the two natural products was studied and compared by using 2D NMR spectroscopy. [source] Nasal challenges with recombinant derivatives of the major birch pollen allergen Bet v 1 induce fewer symptoms and lower mediator release than rBet v 1 wild-type in patients with allergic rhinitisCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2002M. Van Hage-Hamsten Summary Background Genetic engineering of the major birch pollen allergen (Bet v 1) has led to the generation of recombinant Bet v 1 derivatives with markedly reduced IgE-binding capacity, but with retained T cell activating ability. Objective To compare the mucosal reactivity to rBet v 1 derivatives with rBet v 1 wild-type as basis for new therapeutic strategies for birch pollen allergy based on mucosal tolerance induction. Methods Outside the pollen season, 10 patients with birch pollen allergic rhinitis and mild asthma underwent four nasal challenge-sessions in a randomized, double-blind, and cross-over design, employing increasing doses of rBet v 1 fragment mix, rBet v 1 trimer, rBet v 1 wild-type and diluent (albumin). Nasal lavage fluids (NAL) were collected before the challenge-series as well as 10 min, 4 and 24 h thereafter. Nasal lavage fluid levels of tryptase as well as EPO and ECP were measured as indices of mast cell and eosinophil activity, respectively. Results All 10 patients tolerated the highest accumulated dose, 8.124 µg, when challenged with rBet v 1 trimer, eight with rBet v 1 fragments compared to one when challenged with rBet v 1 wild-type. No late phase reactions were observed. The change in tryptase levels (pre-challenge vs. 10 min) was significantly lower after challenges with rBet v 1 trimer and rBet v 1 fragments than with rBet v 1 wild-type. The change in EPO/ECP concentration pre-challenge versus 4 h post-challenge was lower for rBet v 1 trimer and the change was significantly lower when pre-challenge versus 24 h post-challenge to rBet v 1 fragments and rBet v 1 wild-type was examined. Conclusion The derivatives induced significantly fewer symptoms and lower mast cell and eosinophil activation than rBet v 1 wild-type upon application to the nasal mucosa. They could in the future be candidates for immunotherapy based on mucosal tolerance induction. [source] Endogenous glucocorticoids and antigen-induced acute and late phase pulmonary responsesCLINICAL & EXPERIMENTAL ALLERGY, Issue 9 2000Stokes Peebles Background Several studies suggest that endogenous glucocorticoids can dampen the severity of experimental allergic reactions in animals. Objective To investigate the influence that endogenous glucocorticoids have on the course of IgE-mediated pulmonary early and late phase reactions. Methods Twenty-one allergic asthmatic and six healthy control subjects underwent inhaled antigen challenge with measurements of plasma cortisol and cortisone by gas chromatography-mass spectrometry. Results There were no differences between the asthmatic and control groups in the baseline levels of cortisol or cortisone. However, the asthmatic subjects had significantly higher cortisol levels (67.2 ± 8.6 vs 35.1 ± 4.5 ng/mL; P = 0.04) and had higher cortisol/cortisone ratios (4.8 ± 0.6 vs 3.0 ± 0.2; P = 0.01) 8 h after challenge compared to the control subjects. Among the asthmatic subjects, those whose FEV1 recovered rapidly had higher baseline levels of cortisol and those who displayed a late phase reaction had lower levels of cortisol during the late phase period. Conclusion The results suggest that endogenous glucocorticoids may play a significant role in the modulation of airway responses to antigen challenge, and that antigen challenge may induce cortisol production in allergic subjects. [source] | |||||||||||||||||||