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.
Background: Polishing technique for acrylic resin material have great effect on properties of acrylic material and bacterial colonization such as staphylococcus aurous, which are responsible for many acrylic prosthetic infections such as the commonly ocular infections. Ineffective polishing technique could affect roughness and subsequently porosity of acrylic materials.So, a new effective method for polishing acrylic was used depending on the use of optiglaze coating material. So, this study aimed to evaluate the effect of optiglaze polishing on porosity of acrylic resin material and staphylococcus aurous activity in comparison to conventional polishing technique.
Materials and methods: Specimen(n=120) were prepared :20 spe
... Show MoreConducting polyaniline / ZnO nano composites are synthesized
using a simplified cheap method with one step in –situ chemical
polymerization, and AC conductivity (σac) of the prepared samples is
studied in the range of frequency from 50 Hz to 15MHz.). The
presence of polarons in the conjugated polymer chain are responsible
for the ac conductivity is reliance on the frequency in these
composites. The effect of increasing the ZnO nano particle
concentration irradiation and gamma radiation on the electric
conductivity was analyzed. The result showed that the
nanocomposite prepared has the highest conductivity, from pure
polyaniline and the exponential factor S was found increasing with
ZnO content it was 0
Samples prepared by using carbon black as a filler material and phenolic resin as a binder. The samples were pressed in a (3) cm diameter cylindrical die to (250)MPa and treated thermally within temperature range of (600-1000)oC for two and three hours. Physical properties tests were performed, like density, porosity, and X-ray tests. Moreover vicker microhardness and electric resistivity tests were done. From the results, it can be concluded that density was increased while porosity was decreased gradually with increasing temperature and treating time. In microhardness test, it found that more temperature and treating time cause more hardness. Finally the resistivity was decreased in steps with temperature and treating time. It can be c
... Show MoreIn this work, 332 Al alloy was prepared and reinforced with (0.5% and 1%) nano-Al2O3 particles. The prepared unreinforced and reinforced 332 Al alloy with nano-Al2O3 were solution heat treated (T6) at 510 ̊C and aged at 225 ̊C with different times (1, 3, and 5 h). Hardness test was performed on all the prepared alloys. All prepared alloys were dry slided under different applied loads (5, 10, 15, and 20 N) against steel counterface surface using pin on disk apparatus. The results showed that refinement effect was observed after addition of nano-Al2O3 particles and a change in silicon morphology after performing the solution heat treatment. The results also showed that har
... Show MoreDouble drum dryer is operated for producing pregelatinized maize starches using feed starch slurries of different
solids(7, 10 and13 g/100 g )content . Steam pressure (2,3,and 4 bar), the level of pool between the drums (4,7,and 10
cm) , and speed of drums rotation (3,4,and 6 rpm) are varied together with the feed solids content in a practical range of
values. The response of the dryer is registered by measuring several output variables, i.e. external drum temperature,
product moisture content, mass flow rate.
The present study aimed to explain the dose-dependent possible deleterious effects of 30 day administration of Tramadol on some hematological and biochemical parameters of laboratory male rats (Rattus norvegicus), the study consisted of eighteen adult male rats randomly divided into three equal groups (each of six). Group 1 (control) were treated by intraperitoneal injection of normal saline solution (0.2 ml), group two (low dose) was treated by intraperitonealy (i.p) injection of Tramadol at a dose of 50 mg/kg/day, group three (high dose) was treated by intraperitonealy injection of Tramadol at a dose of 100 mg/kg/day for 30 days. At the end of experimental period, rats were sacrificed. Blood were collected by cardiac puncture to inv
... Show MoreNowadays, the use of recycled waste construction materials instead of aggregates is becoming popular in construction owing to its environmental benefits. This paper presents an experimental and analytical campaign to study the behavior of axially loaded columns constructed from recycled aggregates. The latter was used instead of natural aggregates, and they were collected from the waste of previous concrete constructions. Different concrete mixtures made from varying amounts of recycled aggregates ranged from 0 to 50% of the total coarse aggregate were conducted to achieve 28 MPa. The effect of steel fibers is another investigated variable with volumes ranged from 0 to 2% concerning concrete’s mixture. The experimental
... Show MoreThe present study aimed to evaluate the concentration of Malon dialdehyde (MDA) in pregnant women during different stages of pregnancy (stage of pregnancy, abortion, contraceptives and parity number).The study included (120) blood samples from normal pregnant women in age of the procreating were subdivided into three trimesters of pregnancy (40/group), and (40) samples from non-pregnant women as a control group. The results showed a significant increase in MDA in three stages of pregnancy compared with the control group. The concentration of MDA increased significantly in pregnant women with multipregnancy when compared with pregnant women for the first time, and in pregnant women whom was using contraceptions compared with p
... Show MoreOptoelectronic devices, widely used in high energy and nuclear physics applications, suffer severe radiation damage that leads to degradations in its efficiency. In this paper, the influence of gamma radiation (137Ce source) and beta radiation (90Sr source) on the photoelectric parameters of the Si solar cell, based on the I–V characterization at different irradiation exposer, has been studied. The penetrating radiation produces defects in the base material, may be activated during its lifetime, becoming traps for electron–hole pairs produced optically and, this will, decrease the efficiency of the solar cell. The main objective of the paper is to study and measure changes in the I–V characteristics of solar cells, such as efficienc
... Show MoreIn the present work, nanocomposite of poly (vinyl alcohol) (PVA) incorporated with functionalized graphene oxide (FGO) were fabricated using casting method. PVA was dispersed by varying content of FGO (0.3, 0.5, 0.8, 1 wt %). The PVA- FGO nanocomposite was characterized by FT‐IR, FE-SEM and XRD. Frequency dependence of real permittivity (ε’), imaginary (ε’’) and a.c conductivity of PVA/FGO and PVA/GO nanocomposite were studied in the frequency range 100 Hz- 1 MHz. The experimental results showed that the values of real (ε’) and imaginary permittivity (ε’’) increased dramatically by increasing the FGO content in PVA matrix. PVA/ FGO (1 wt %) nanocomposite revealed higher electrical conductivity of 6.4×10-4 Sm-1 compared to
... Show More