Drug hypersensitivity involves the activation of T cells in an HLA allele–restricted manner. Because the majority of individuals who carry HLA risk alleles do not develop hypersensitivity, other parameters must control development of the drug-specific T cell response. Thus, we have used a T cell–priming assay and nitroso sulfamethoxazole (SMX-NO) as a model Ag to investigate the activation of specific TCR Vβ subtypes, the impact of programmed death -1 (PD-1), CTL-associated protein 4 (CTLA4), and T cell Ig and mucin domain protein-3 (TIM-3) coinhibitory signaling on activation of naive and memory T cells, and the ability of regulatory T cells (Tregs) to prevent responses. An expansion of the TCR repertoire was observed for nine Vβ subtypes, whereas spectratyping revealed that SMX-NO–specific T cell responses are controlled by public TCRs present in all individuals alongside private TCR repertoires specific to each individual. We proceeded to evaluate the extent to which the activation of these TCR Vβ–restricted Ag-specific T cell responses is governed by regulatory signals. Blockade of PD-L1/CTLA4 signaling dampened activation of SMX-NO–specific naive and memory T cells, whereas blockade of TIM-3 produced no effect. Programmed death-1, CTLA4, and TIM-3 displayed discrete expression profiles during drug-induced T cell activation, and expression of each receptor was enhanced on dividing T cells. Because these receptors are also expressed on Tregs, Treg-mediated suppression of SMX-NO–induced T cell activation was investigated. Tregs significantly dampened the priming of T cells. In conclusion, our findings demonstrate that distinct TCR Vβ subtypes, dysregulation of coinhibitory signaling pathways, and dysfunctional Tregs may influence predisposition to hypersensitivity.
The ability of different alumina-grafted particles was examined for adsorption of phenol and p-chlorophenol under different conditions (i.e. concentrations and temperatures). Dispersion stability of alumina in liquid medium (water) was studied using settling under gravity technique. The result shows the settling initial rate of the alumina-grafted acrylic acid particles was faster than initial rate of settling when alumina-graft acrylic acid monomer adsorbed phenol and p-chlorophenol and vice versa to the alumina-graft poly(acrylic acid) polymer.
Thermodynamic parameters values (DG, DS, DH) were calculated for adsorption processes of phenol and p-chlorophenol adsorbed onto different surfaces. The
... Show MoreThe work concerned with studying the effect of (SiO2) addition as a
filler on the adhesive properties of (PVA). Samples were prepared as
sheets by using casting method. The mechanical properties showed
that increase in tensile strength from (34MPa) to (68MPa) when
(SiO2) added to (PVA). The adhesive strength showed that joint
properties depend upon specific adhesive characteristic of material
(PVA) and (SiO2\PVA)composites at different concentrations (1.5%,
2.5%, 3.5%, 4.5wt%), the cohesive strength of the adhesive material,
the joint design, and adherent type (Sponge Rubber(SR), Natural
leather (NL), Vulcanized Rubber(VR), and Cartoon). The results
proved the tensile strength increased with (SiO2) ratio, so
A field experiment was carried out to find out the effect of some herbicides(Pallas, Crash, U46) on the companion weed to three cultivars of the oat crop (Shefa, Hamel, and Pimula) and the yield and its components of these cultivars. The results showed the superiority of the two treatments of spraying weed herbicides (T1 and T2 ) by giving the best results, as they recorded the lowest number of weed plants after 30 days of spraying reached 1.44 and 1.67 plant/m2 . Besides, the lowest weed dry weight was 0.11 and 0.00 g/m2, and the highest inhibition percentage in dry weight was 98.44% and 100.0% of the two treatments, respectively. The treatment T2 was also superior by giving the highest control percentage of 93.28% compared to the compari
... Show MoreIn this paper, SiO2 nanoparticles thin films were synthesised at different PH values of solution by sol gel method at fixed temperature (25oC) and molar ratio (R =H2O/precursor) of (Tetra Ethyl Ortho Silicate) TEOS as precursor at (R=1). The structure and optical properties of the thin films have been investigated. All thin films were tested by using X-RAY diffraction. All X-RAY spectrum can be indexed as monoclinic structure with strong crystalline (110) plane. The morphological properties of the prepared films were studied by SEM. The results indicate that all films are in nano scale and the particle size around (19-62) nm .The size of silica particles increases with increasing PH value of solution where both the rate of hydrolysis and
... Show MoreThe perturbation of a satellite high orbit due to the presence of other
gravitational bodies (such as the Sun and the Moon) and SRP from the conservative
perturbing forces were studied, using our modified model. A precise calculation of
the perturbations is possible only if the initial orbit is sufficiently well known.
Orbital elements that have been entered hp=3000Km., inclination= 63ᵒ, 23ᵒ and
eccentricity= 0.1, longitude of ascending node 30ᵒ, argument of perigee 40ᵒ where
the orbital elements will deviate from initial values with time through 3000 days.
Newton-Rapson method was used to calculate the position and velocity with out
perturbation . The perturbed equation of motion solved numerically using
Faujasite type NaY zeolite catalyst was prepared from locally available kaolin, then the prepared NaY zeolite have been modified by exchanging of sodium ion with ammonium to produce NH4Y zeolite. NH4Y zeolite was converted to HY zeolite by ion exchanging with oxalic acid. Zinc and nickel promoters have been added to the prepared HY zeolite catalyst, and the effect of these promoters on the catalytic activity of the prepared HY catalyst was studied in fluid catalytic cracking process using light gas oil as a feedstock. The experimental results show that the promoted catalyst gives higher gas oil conversion and gasoline yield than HY zeolite catalyst at the same reaction temperature and WHSV. It was also found that the promoted catalyst gi
... Show MoreThis research dealt with choosing the best satellite parking orbit and then the transition of the satellite from the low Earth orbit to the geosynchronous orbit (GEO). The aim of this research is to achieve this transition with the highest possible efficiency (lowest possible energy, time, and fuel consumption with highest accuracy) in the case of two different inclination orbits. This requires choosing a suitable primary parking orbit. All of the methods discussed in previous studies are based on two orbits at the same plane, mostly applying the circular orbit as an initial orbit. This transition required the use of the advanced technique of the Hohmann transfer method for the elliptical orbits, as we did in an earlier research, namely
... Show MoreBackground: Tobacco smoking and tuberculosis (TB) are two major public health problems; Associations between smoking and tuberculosis including death from tuberculosis have been reported , A reduction in smoking could be expected to have a significant impact on TB incidence and prevalence .
Objectives: to assess the effect of smoking on tuberculosis.
Methods: This study was conducted from June 2011 to June 2012 in 200 patients, adult ( aged 17 years and more), newly diagnosed patients of pulmonary tuberculosis, at the chest and Respiratory Disease Specialized Center in Baghdad. Demographic data, presenting symptoms, data on smoking, and recurrence of disease were compared. Information on smoking status, tobacco smoking was collecte
In this study, the effect of ceramic coating on the performance and gases emission on diesel engine was investigated. A four-stroke, direct injected, single cylinder, diesel engine was tested at constant speed and at different load conditions without coating. Then, the inlet and exhaust valves faces were coated by about 500µm with ceramic materials. Ceramic layers were made of YttriaStabilized Zirconia (YSZ), and NiCrAl as a bond coat. The coating technique adapted in this work is the flame spray method. The engine with valves ceramiccoated research was tested for the same operation conditions of the engine (without coating). The results indicate a reduction in both fuel consumption by about 7.6% and particulate emissions by about (13
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