			Home About us Contact

Polystyrene Plates (polystyrene + plate)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Polypropylene glycol is a selective binding inhibitor for LTA and other structurally related TLR2 agonists

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2008
Christian Draing
Abstract Polypropylene glycol (PPG) is commonly added to bacterial cultures to avoid foaming. However, lipoteichoic acid (LTA) from bacteria grown with PPG lacked cytokine-inducing potency in human blood. We tested the blocking efficacy of several glycols on the cytokine response to staphylococcal LTA in human blood. PPG 1200 was the most potent inhibitor tested, shown for TNF, IL-1,, IL-6, IL-8, IL-10 and TGF-, induction, and displayed no cytotoxic effects. TNF induction by Staphylococcus aureus or by Toll-like receptor (TLR)2 agonists (di- and triacylated lipopeptides and LTA) was also inhibited by PPG 1200, but not that induced by Escherichia,coli or TLR4 agonists. In flow cytometric studies, PPG-carrying nanobeads bound more rhodamine-labeled LTA than those with glycerol. Additionally, the methyl group peak in the 1H-NMR of LTA shifted after incubation with increasing PPG 1200 concentrations. Sequential incubation of polystyrene plates with LTA, then PPG 1200 and then blood, with washing steps in between, showed that LTA-induced TNF release was inhibited. But when PPG 1200 was pre-incubated with blood that was washed before LTA was added, TNF induction was not repressed, demonstrating that PPG binds LTA and not cellular structures. In summary, PPG 1200 is a novel inhibitor of cytokine induction by TLR2 agonists, which interferes directly with the ligands. [source]

A new ELISA assay for diagnosis of acquired von Willebrand Syndrome

HAEMOPHILIA, Issue 3 2003
C. Siaka
Summary. The pathophysiology of acquired von Willebrand syndrome (AVWS), a rare bleeding disorder, is not fully understood. Circulating antibodies to Von Willebrand factor (VWF) are found in patients with AVWS associated with lymphoproliferative disorders but these autoantibodies are difficult to detect with routine laboratory tests and neutralisation assays. We have developed a simple enzyme-linked immunosorbent assay (ELISA) to detect serum antibody binding to VWF protein immobilized on polystyrene plates. Ten patients with AVWS were studied, eight of whom also had lymphoproliferative disorders. We found antibodies in eight patients; all of them were positive for IgG and five were also positive for IgM. This simple method appears to be more sensitive than functional assays, which failed to identify two of the patients who were positive with the ELISA. In conjunction with other tests, this ELISA method may be useful for demonstrating the immunological mechanism underlying some cases of AVWS. Such patients would qualify for intravenous immunoglobulin therapy, which can correct the clotting disorder. [source]

Evaluation of mechanical properties of adjacent flow weldline

POLYMER ENGINEERING & SCIENCE, Issue 8 2005
Koji Yamada
Weldlines occur at the interface of two adjacent flows of material behind an obstructive pin in a cavity in injection molding (meldline or hot weldline). Tensile strength of such "adjacent flow weldline" in injection molded polystyrene plates was evaluated by a mechanical step-by-step milling technique. The strength when the milling depth was 1/5 of the thickness from each surface was about the same and independent of the distance from the pin. In contrast, the strength without milling decreased once and then increased along the flow direction. This demonstrates that the strength of a weldline is predominantly dependent on the properties of the surface layer of the weldline. The depth of the surface layer was defined as the depth of the weld, Dw. Dw reduced monotonously along the flow direction and faded away with the V-notch, resulting in an increase of strength along the direction. On the other hand, it was considered that the farther from the pin, the flow-induced molecular orientation in the surface layer is greater. It caused a decrease of the strength along the flow direction. The sequence of decrease and increase in tensile strength of adjacent flow weldline is due to the complex effect of these two contradictory factors. POLYM. ENG. SCI., 45:1180,1186, 2005. © 2005 Society of Plastics Engineers [source]

ORIGINAL ARTICLE: Murine Monoclonal Antibody 26 Raised Against Tetanus Toxoid Cross-Reacts with ,2 -Glycoprotein I: Its Characteristics and Role in Molecular Mimicry

AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 1 2009
Aleksandra Inic-Kanada
Problem, Studies on experimental antiphospholipid syndrome (APS) models proved that molecular mimicry between plasma protein ,2 -glycoprotein I (,2GPI) and structure within micro-organisms or their products, might be a cause for experimental APS. Considering the heterogeneity of polyclonal antiphospholipid antibodies (aPLs), it is important to define the precise characteristics of pathogenic aPLs. To avoid the influence of polyclonality and to further analyse the connection between molecular mimicry and APS, we produced monoclonal antibodies (MAbs) against tetanus toxoid (TTd) and tested their reactivity against ,2GPI. Method of study, In this report, we analysed the characteristics of MAb26 raised against TTd and cross-reactive with ,2GPI: its binding properties in various in vitro immunoassays, its specific interactions with surface epitopes expressed on apoptotic cells and its role in vivo. Results, We have demonstrated that MAb26: (i) binds ,2GPI being immobilized on an appropriate surface: irradiated polystyrene plates, non-irradiated plates pre-coated with anionic phospholipids and polyvinylidene fluoride membrane; (ii) binds specifically to apoptotic but not to viable cells and the binding is ,2GPI-dependent; and (iii) induces a pathologic pregnancy outcome when passively injected into BALB/c mice. Conclusion, This study concluded that certain subpopulations of antibodies raised against TTd and cross-reactive with ,2GPI, because of the molecular mimicry mechanism, could have pathologic potential. [source]