Infiltration of cells

When a foreign substance comes in contact with the human body, the system initiates its host defense m hanisms involving what may be called the inflammatory response. For instance, the presence of foreign materials causes acute inflammatory changes, evokes an immune reaction, or is associated with infiltrate of cells predominantly of the mononuclear phagocyte after an acute inflammatory reaction. It is the macrophage that is the most important cell in the mononuclear phagocyte system (MPS) which plays a major role in all these kinds of inflammation. 

Migration and infiltration of cells into tissue engineering scaffolds are crucial factors for their success. Many types of scaffold design require that cells seeded in vitro or recruited in vivo are allowed to infiltrate and populate the scaffolds quickly. Microstructure has a significant effect on cell migration and infiltration, and understanding these effects may lead to better scaffold design. 

Fig. 8. Sensitized guinea pig. Nipple 37-2 hours after a single application of 0.1% DNCB in acetone beginning of spongiosis, dermal infiltration of cells giving a positive reaction...

Fig. 18. Liver of a rat suffering from choline deficiency (low-protein, high-fat diet). Note extensive fatty infiltration of cells. Fibrous tissue has developed which divides organ up into lobules which bear little relation to the normal anatomical lobular arrangement.

Although many efforts have been devoted to increasing the infiltration of cells into a nanofibrous constructs, a robust and transferrable scaffold has yet to be developed and remains a major goal of future work. 

When exposure is repeated, the allergen binds between two adjacent IgE molecules. This causes release of inflammatory mediators (histamine, leukotrienes, chemotactic factors). These act locally and cause smooth muscle contraction, increased vascular permeability, mucous gland secretion, and infiltration of inflammatory cells (neutrophils and eosinophils). However, histamine can also be released by non-IgE-mediated mechanisms (e.g., due to exposure to certain fungi). 463... 

EDI), and water to produce a group of biodegradable PU foams. The interconnected pores varied in size from 10 to 2 mm in diameter. Rabbit bone-marrow stromal cells cultured on the materials for up to 30 days formed multilayers of confluent cells and were phenotypically similar to those grown on tissue culture PS. It supported the adherence and proliferation of both bone-marrow stromal cells and chondrocytes in vitro. In subdermal implants the investigators found that the material showed infiltration of both vascular cells and connective tissue. 

Malefyt R. Meng Q. Kay AB. Phipps S. Lee TH. Ying S Early production of thymic stromal lymphopoie-tin precedes infiltration of dendritic cells expressing its receptor in allergen-induced late phase cutaneous responses in atopic subjects. Allergy 2009 64 1014-1022. 

Mastocytomas and diffuse cutaneous mastocytosis are further manifestations of cutaneous mastocytosis (CM) [9]. Solitary mastocytomas are common in children. Most are present at birth or develop in infancy. These lesions are flat or mildly elevated, well demarcated, solitary yellowish red-brown plaques or nodules, typically 2-5 cm in diameter. Diffuse cutaneous mastocytosis is a rare disorder characterized by diffuse mast cell infiltration of large areas of the skin that presents in infants in the first year of life. Severe edema and leathery indurations of the skin leads to accentuation of skin folds (pseudo-lichenified skin) and a peau-dbrange-like appearance. Systemic complications include hypotension and gastrointestinal hemorrhage. Infants and young children with considerable mast cell infiltration of the skin sometimes exhibit blister formation in the first 3 years of life. MPCM and other forms of CM have been classified in a consensus nomenclature (table 1) [10]. 

Multifocal dense infiltrates of mast cells in bone marrow and/or other extracutaneous organs... 

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