Lymphocyte transformation test reveals low prevalence of true metal hypersensitivity among pre-operative total knee arthroplasty patients.

Purpose: The aims of this study were to determine the prevalence of metal hypersensitivity, and identify pre-operative factors which could predict susceptibility to hypersensitivity reactions among patients scheduled for primary total knee arthroplasty (TKA). The present study used a testing method consistent with the recognised biological response to metals.

Methods: A prospective cross-sectional analysis of 220 patients was conducted.

The pathophysiology of immunoporosis: innovative therapeutic targets.

Background: The physiological balance between bone resorption and bone formation is now known to be mediated by a cascade of events parallel to the classic osteoblast-osteoclast interaction. Thus, osteoimmunology now encompasses the role played by other cell types, such as cytokines, lymphocytes and chemokines, in immunological responses and how they help modulate bone metabolism. All these factors have an impact on the RANK/RANKL/OPG pathway, which is the major pathway for the maturation and resorption activity of osteoclast precursor cells, responsible for osteoporosis development.

Evidence Supporting the Safety of Pegylated Diethylaminoethyl-Chitosan Polymer as a Nanovector for Gene Therapy Applications.

Purpose: Diethylaminoethyl-chitosan (DEAE-CH) is a derivative with excellent potential as a delivery vector for gene therapy applications. The aim of this study is to evaluate its toxicological profile for potential future clinical applications.

Methods: An endotoxin-free chitosan (CH) modified with DEAE, folic acid (FA) and polyethylene glycol (PEG) was used to complex small interfering RNA (siRNA) and form nanoparticles (DEAE-CH-PEG-FA/siRNA).

In vitro and in vivo assessment of the proresolutive and antiresorptive actions of resolvin D1: relevance to arthritis.

Background: Resolvin D1 (RvD1), an important member of resolvins, exerts a wide spectrum of biological effects, including resolution of inflammation, tissue repair, and preservation of cell viability. The aim of the present study is to investigate the anti-arthritic potential and clarify the bone protective actions of RvD1 in vitro and in vivo.

Methods: RAW264.

Biological activities of interleukin (IL)-21 in human monocytes and macrophages.

The biological roles of interleukin (IL)-21 in human monocytes and macrophages have been neglected. We previously demonstrated that IL-21 induce phagocytosis and established that Syk is a new molecular target of IL-21. Herein, we found that IL-21 is not chemoattractant for immature THP-1 and primary monocytes but can increase the capacity of THP-1 cells (not primary monocytes) to adhere onto a cell substratum by a Syk-dependent mechanism without altering the expression of a panel of cell surface molecules.

Activation of human AML14.3D10 eosinophils by nanoparticles: Modulatory activity on apoptosis and cytokine production.

Eosinophilic inflammation is frequently observed in response to nanoparticle (NP) exposure in airway rodent models of allergies where the number of eosinophils is increased in lungs. Despite this, it is surprising that the potential cytotoxic effect of NP, as well as their direct role on eosinophils is poorly documented. The present study investigated how different NP can alter the biology of the human eosinophilic cell line AML14.

Prolonged cultures of unstimulated human neutrophils lead to the apparition and persistence of rest-in-plate structures (RIPs) recognized by professional phagocytes in vitro and in vivo.

Polymorphonuclear neutrophil cells (PMNs) are known to spontaneously undergo apoptosis and then eliminated by professional phagocytes to prevent inflammation, a process called efferocytosis. However, when efferocytosis is impaired, PMNs will fall into secondary necrosis. Whether this state can persist for a certain period of time is unclear, since most of the studies investigating secondary necrosis are performed within 24h following induction by a proapoptotic agent.

Silver nanoparticles induce degradation of the endoplasmic reticulum stress sensor activating transcription factor-6 leading to activation of the NLRP-3 inflammasome.

In the past decade, the increasing amount of nanoparticles (NP) and nanomaterials used in multiple applications led the scientific community to investigate the potential toxicity of NP. Many studies highlighted the cytotoxic effects of various NP, including titanium dioxide, zinc oxide, and silver nanoparticles (AgNP). In a few studies, endoplasmic reticulum (ER) stress was found to be associated with NP cytotoxicity leading to apoptosis in different cell types.

IL-21 enhances phagocytosis in mononuclear phagocyte cells: identification of spleen tyrosine kinase as a novel molecular target of IL-21.

The biological significance of the IL-21/IL-21R system in human monocytes/macrophages is not well documented, and the expression of IL-21R is unclear and has been disputed. In this study, we showed for the first time, to our knowledge, that human monocyte-like THP-1 cells expressed the two IL-21R components, CD132 (γc) and IL-21Rα, on their cell surface, as assessed by flow cytometry. Moreover, IL-21 was found to enhance FcR-mediated phagocytosis, but not endocytosis.