shiga toxins (stxs) are bacterial virulence factors produced by shigella dysenteriae serotype 1 and escherichia coli strains. stxs are critical factors for the development of diseases such as severe bloody diarrhea and hemolytic uremic syndrome. additionally, stxs trigger the secretion of pro- inflammatory cytokines and chemokines, particularly in monocytes or macrophages. the inflammatory cyto...

Mast cells have been implicated in the pathogenesis of fibrosis because of their increased number in chronic inflammatory reactions. In a previous study, we had shown that human mast cells readily attach and form heterotypic cell-cell contacts when seeded on top of fibroblast monolayers. Here, we report that human mast cells stimulate fibroblast proliferation after cell-cell contact. Proliferat...

Primate alpha-chymases are mast cell neutral proteases that are involved in regulating several regulatory peptides including angiotensin II. Because of significant substrate specificity differences among the chymase group of enzymes, animal models that overexpress primate chymases are crucial for delineating the in vivo function of these enzymes. Activation of alpha-prochymase requires processi...

Degradation of the extracellular matrix occurs under physiological and pathological conditions, thought to be principally mediated by a family of neutral proteolytic enzymes termed the matrix metalloproteinases (MMPs). The present study was initiated to determine whether mast cells have the ability to produce these proteases in diseased and normal human tissue. Immunohistochemistry and in situ ...

Background and objective:Gingival bleeding reduction in smokers has been associated with decreased blood vessel density. The mechanism of suppressive effect of cigarette smoking on blood vessel density is not precisely defined. The aim of this study was to evaluate the impact of smoking on angiogenesis by assessing mast cells density and VEGF expression in chronic peri...

Primary cutaneous lymphomas (PCLs) are clonal Tor B-cell neoplasms, which originate in the skin. In recent years, mast cells were described as regulators of the tumor microenvironment in different human malignancies. Here, we investigated the role of mast cells in the tumor microenvironment of PCL. We found significantly increased numbers of mast cells in skin biopsies from patients with cutane...

Primary cutaneous lymphomas (PCLs) are clonal T- or B-cell neoplasms, which originate in the skin. In recent years, mast cells were described as regulators of the tumor microenvironment in different human malignancies. Here, we investigated the role of mast cells in the tumor microenvironment of PCL. We found significantly increased numbers of mast cells in skin biopsies from patients with cuta...

OBJECTIVES The significance of the mast cell in the pathogenesis of rheumatic diseases has become more evident. Although mast cell hyperplasia is a feature of rheumatoid arthritis, the nature of mast cell chemoattractants involved in the recruitment of mast cells in joint diseases has not been studied in any detail. In this study the presence of mast cell chemotactic activity in synovial fluids...

Mast cells play a central role in type I hypersensitivity reactions and allergic disorders such as anaphylaxis and asthma. Activation of mast cells, through a cascade of phosphorylation events, leads to the release of mediators of the early phase allergic response. Understanding the molecular architecture underlying mast cell signaling may provide possibilities for therapeutic intervention in a...