Polymorphonuclear leukocytes eosinophils

LEUKOCYTES. Leukocytes are white blood cells involved in the cellular and humoral defense of the organism against foreign materials. They are grouped into two classes polymorphonuclear leukocytes, which comprise neutrophils, eosinophils, and basophils, and mononuclear leukocytes that include lymphocytes and monocytes. Of these, neutrophils and lymphocytes have been suggested as potential cellular carriers. 

The full name of these cells is neutrophilic polymorphonuclear leukocytes, but the terms neutrophil and, less-commonly now, polymorph are generally used to describe this cell (Fig. 1.1a). In fact, most preparations of neutrophils contain about 95-97% neutrophils, the remainder being largely eosinophils, because the commonly-used separation techniques do not efficiently separate these cell types. Neutrophils are the most abundant white cell in the blood, accounting for 40-65% of white blood cells, and are found at concentrations usually in the range 3-5 x 106 cells/ml blood. This number can increase dramatically (up to tenfold) in cases of infection. They have a relatively short half-life in the circulation (estimated at about 8-20 h), but this may be extended to up to several days if the cells leave the circulation and enter tissues - although it is difficult to measure the lifespan of a tissue neutrophil. Because of the large numbers of neutrophils in the circulation and their relatively short lifespan, vast numbers of neutrophils enter and... 

Neutrophils, monocytes, macrophages, eosinophils, basophils, and polymorphonuclear leukocytes are all affected by several or all of these factors. Binding to specific receptors results in a variety of changes in the cells. These include alterations in membrane potential, cyclic nucleotide levels, and ion fluxes (Na+, K+, Ca2+) as well as increased methylation of specific proteins. 

Granulocytes (polymorphonuclear leukocytes) Neutrophils Eosinophils Basophils/mast cells"... 

Nedocromil was developed as a result of research for compounds to control asthma. Its activity has been studied in vitro in a variety of inflammatory cells, including mast cells, eosinophils, and polymorphonuclear leukocytes. Nedocromil appears to be more potent than cromolyn in its ability to inhibit immimologic release of mast cell mediators. It can also modify the actions of eosinophils, neutrophils, monocytes, macrophages, and platelets. Pharmacokinetic studies indicate that ocular penetration of nedocromil is slow, and clearance from the eye is relatively rapid. Nedocromil differs from the other mast cell stabilizers in that it is effective within 15 to 30 minutes. 

Specifically, the giant papillae found in VKC consist of dense fibrous tissue (connective tissue hyperplasia) as well as eosinophils, mast cells, basophils, polymorphonuclear leukocytes, lymphocytes, and macrophages. Mucous discharge contains eosinophils. Trantas dots, which appear as elevated white opacities at the limbus, contain eosinophils and epithelial cells. 

PAF stimulates polymorphonuclear leukocytes to aggregate, to release LTs and lysosomal enzymes, and to generate superoxide. PAF also promotes aggregation of monocytes and degranulation of eosinophils. It is chemotactic for eosinophils, neutrophils, and monocytes and promotes endothelial adherence and diapedesis of neutrophils. When given systemically, PAF causes leuko-cytopenia, with neutrophils showing the greatest decline. 

Lipoxygenases may act at carbons 5, 12, or 15. The type of lipoxygenase varies from tissue to tissue. For example, polymorphonuclear leukocytes contain primarily 5-lipoxygenase, platelets are rich in 12-lipoxygenase, and eosinophilic leukocytes contain primarily 15-lipoxygenase. 

Polymorphonuclear leukocyte A white blood cell which possesses a nucleus composed of two or more lobes or parts a granulocyte (neutrophil, eosinophil, basophil). 

The occurrence of 5-lipoxygenase was implicated from the isolation of 5-hydroxy-6,8,11,14-eicosatetraenoic acid produced from arachidonic add by rabbit polymorphonuclear leukocytes [194]. The enzyme is now known to initiate the biosynthetic pathway of some leukotrienes, and is considered to occur in various leukotriene-synthesizing tissues rabbit peritoneal polymorphonuclear leukocytes [194], murine mastocytoma cells [201], human polymorphonuclear leukocytes [202], rat peritoneal mononuclear cells [203,204], rat basophilic leukemia cells [205,206], and horse eosinophils [207]. The 10000 X g supernatant of rat basophilic leukemia cells produces 5-hydroxy arachidonic acid, and the reaction requires the presence of caldum ion and glutathione [206]. The 100000 X g supernatant of guinea pig peritoneal polymorphonuclear leukocytes contains a 5-lipoxygenase, which also requires calcium ion and produces 5-hydroperoxy acid in the absence of glutathione [199]. 

Goetzl EJ, Woods M and Gorman RR Stimulation of human eosinophil and neutrophil polymorphonuclear leukocyte chemotaxis and randan migration by 12-HETE. J CZyin Inv y6t 59 179-183, 1977. 

Varying degrees of keratitis were present in the majority of rats in group A consisting of one or more of the following features polymorphonuclear leukocyte infiltration of the corneal epithelium, stroma or Descemet s membrane, the presence of blood vessels in the stroma, hyperplasia of the epithelium, vacuolar degeneration of the epithelium and eosinophil infiltration into the stroma (figure 3),... 

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