Covalent modification of protein by drugs may disrupt self-tolerance, leading to lymphocyte activation. Until now, determination of the threshold required for this process has not been possible. Therefore, we performed quantitative mass spectrometric analyses to define the epitopes formed in tolerant and hypersensitive patients taking the β-lactam antibiotic piperacillin and the threshold required for T cell activation. A hydrolyzed piperacillin hapten was detected on four lysine residues of human serum albumin (HSA) isolated from tolerant patients. The level of modified Lys541 ranged from 2.6 to 4.8%. Analysis of plasma from hypersensitive patients revealed the same pattern and levels of modification 1–10 d after the commencement of therapy. Piperacillin-responsive skin-homing CD4+ clones expressing an array of Vβ receptors were activated in a dose-, time-, and processing-dependent manner; analysis of incubation medium revealed that 2.6% of Lys541 in HSA was modified when T cells were activated. Piperacillin–HSA conjugates that had levels and epitopes identical to those detected in patients were shown to selectively stimulate additional CD4+ clones, which expressed a more restricted Vβ repertoire. To conclude, the levels of piperacillin–HSA modification that activated T cells are equivalent to the ones formed in hypersensitive and tolerant patients, which indicates that threshold levels of drug Ag are formed in all patients. Thus, the propensity to develop hypersensitivity is dependent on other factors, such as the presence of T cells within an individual’s repertoire that can be activated with the β-lactam hapten and/or an imbalance in immune regulation.
Spin coating technique has been applied in this work to prepared Xerogel films doped with Rhodamine 6G laser dyes. The solid host of laser dye modifies its spectroscopic properties with respect to liquid host. During the spin coating process the dye molecules suffer from changing their environment. The effects of three parameters were studied here: the spinning speed, multilayer coating and formaldehyde addition
Iraqi calcium bentonite was activated via acidification to study its structural and electrical properties. The elemental analysis of treated bentonite was determined by using X-ray fluorescence while the unit crystal structure was studied through X-ray diffraction showing disappearance of some fundamental reflections due to the treatment processes. The surface morphology, on the other hand, was studied thoroughly by Scanning Electron microscopy SEM and Atomic Force Microscope AFM showing some fragments of montmorillonite sheets. Furthermore, the electrical properties of bentonite were studied including: The dielectric permittivity, conductivity, tangent loss factor, and impedance with range of frequency (0.1-1000 KHz) at different temperatu
... Show MoreABSTRACT : Fifteenth isolates of C. sakazakii were obtained from previous studies of the sample (infant formula, cerebrospinal fluid and blood). All isolates C. sakazakii identification based on microscopic, biochemical test and confirmed by 16SrRNA. We studied the movement of all isolates and study adhesion to polystyrene plate, adhesion and invasion to Esophageal adenocarcinoma (SKG-GT-4) for four isolates [Cerebrospinal fluid (CSF5), Bloods (B 1), Dialak (A1c), Novolac Allernova (C1)] and its cytotoxicity. Results showed that all isolates can move after 4 hours of incubation and increased after 8 hours, the isolates moved to different distances strong, medium, and weak. The results showed that the number of C. sakazakii colony adherent t
... Show MoreThe focus of this research revolves around the importance level of sialic acid in the reasoning of cases, including tumors and then evaluate the patient's response to treatment and its impact on the immune response there are a lot of evidence showing that parts Alkrbu ???????? in peptides sugary and glycoproteins play an important role in Alfalitin life and responsiveness
The analysis, behavior of two-phase flow incompressible fluid in T-juction is done by using "A Computational Fluid Dynamic (CFD) model" that application division of different in industries. The level set method was based in “Finite Element method”. In our search the behavior of two phase flow (oil and water) was studed. The two-phase flow is taken to simulate by using comsol software 4.3. The multivariable was studying such as velocity distribution, share rate, pressure and the fraction of volume at various times. The velocity was employed at the inlet (0.2633, 0.1316, 0.0547 and 0.0283 m/s) for water and (0.1316 m/s) for oil, over and above the pressure set at outlet as a boundary condition. It was observed through the program
... Show MoreBack ground: Oral lichen planus is a chronic inflammatory disease that affects the mucous membrane of the mouth. Several researchers suggest that oxidative stress is implicated in the pathogenesis of this disorder. It has been hypothesized that melatonin is powerful anti-oxidants and can easily cross the cell membrane and is considered a free radical scavenger of Hydroxid, Oxygen and Nitrogen dioxide, cortisol as a stress hormone and the immunoglobulin A as first line of defense and protection to the mucous membrane of the mouth are interrelated factors for the emergence of oral lichen planus. Aim of this study was to evaluate the level of melatonin, Cortisol and IgA in saliva of patients with oral lichen planus lesions in comparison with p
... Show MoreBackground: The marginal fit is the most characteristic that closely related to the longevity or success of a restoration, which is absolutely affected by the fabrication technique. The objective of present in vitro study was to evaluate the effect of four different CAD/CAM systems on the marginal fit of lithiµm disilicate all ceramic crowns. Materials and Methods: Adentoform tooth of a right mandibular first molar was prepared to receive all ceramic crown restoration with deep chamfer finishing line (1mm) and axial reduction convergence angle of 6 degree, dentoform model duplicated to have Nickel-Chromiµm master die. Thirty two stone dies produce from master die and distributed randomly in to four groups (8 dies for each group) accor
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