Mercury induces inflammatory mediator release from human mast cells

<p>Abstract</p> <p>Background</p> <p>Mercury is known to be neurotoxic, but its effects on the immune system are less well known. Mast cells are involved in allergic reactions, but also in innate and acquired immunity, as well as in inflammation. Many patients with Autism Spectrum Disorders (ASD) have "allergic" symptoms; moreover, the prevalence of ASD in patients with mastocytosis, characterized by numerous hyperactive mast cells in most tissues, is 10-fold higher than the general population suggesting mast cell involvement. We, therefore, investigated the effect of mercuric chloride (HgCl₂) on human mast cell activation.</p> <p>Methods</p> <p>Human leukemic cultured LAD2 mast cells and normal human umbilical cord blood-derived cultured mast cells (hCBMCs) were stimulated by HgCl2 (0.1-10 μM) for either 10 min for beta-hexosaminidase release or 24 hr for measuring vascular endothelial growth factor (VEGF) and IL-6 release by ELISA.</p> <p>Results</p> <p>HgCl₂induced a 2-fold increase in β-hexosaminidase release, and also significant VEGF release at 0.1 and 1 μM (311 ± 32 pg/10⁶cells and 443 ± 143 pg/10⁶cells, respectively) from LAD2 mast cells compared to control cells (227 ± 17 pg/10⁶cells, n = 5, p < 0.05). Addition of HgCl₂(0.1 μM) to the proinflammatory neuropeptide substance P (SP, 0.1 μM) had synergestic action in inducing VEGF from LAD2 mast cells. HgCl₂also stimulated significant VEGF release (360 ± 100 pg/10⁶cells at 1 μM, n = 5, p < 0.05) from hCBMCs compared to control cells (182 ± 57 pg/10⁶cells), and IL-6 release (466 ± 57 pg/10⁶cells at 0.1 μM) compared to untreated cells (13 ± 25 pg/10⁶cells, n = 5, p < 0.05). Addition of HgCl₂(0.1 μM) to SP (5 μM) further increased IL-6 release.</p> <p>Conclusions</p> <p>HgCl₂stimulates VEGF and IL-6 release from human mast cells. This phenomenon could disrupt the blood-brain-barrier and permit brain inflammation. As a result, the findings of the present study provide a biological mechanism for how low levels of mercury may contribute to ASD pathogenesis.</p

Profiling Attitudes for Personalized Information Provision

PAROS is a generic system under design whose goal is to offer personalization, recommendation, and other adaptation services to information providing systems. In its heart lies a rich user model able to capture several diverse aspects of user behavior, interests, preferences, and other attitudes. The user model is instantiated with profiles of users, which are obtained by analyzing and appropriately interpreting potentially arbitrary pieces of user-relevant information coming from diverse sources. These profiles are maintained by the system, updated incrementally as additional data on users becomes available, and used by a variety of information systems to adapt the functionality to the users’ characteristics

A survey of context-aware cross-digital library personalization

The constant interaction of users with different Digital Libraries (DLs) and the subsequent scattering of user information across them raise the need not only for Digital Library interoperability but also for cross-Digital Library personalization. The latter calls for sharing and combining of user-information across different DL systems so that a DL system may take advantage of data from others. To achieve this goal, DL systems should be able to maintain compliant and interoperable user models and profiles that enable propagation and reconciliation of user information across different DLs. In this paper, we motivate the need for cross-Digital Library personalization, we define and examine user model, profile, and context interoperability, and we survey and discuss existing user model interoperability approaches