Phagocytic activities

Bacteria bind to complement components and the bacterium-complement complexes bind complement receptors on the surface of macrophages. Phagocytosis may also be mediated by specific antibodies that function as opsonins, which bind to particles, rendering them susceptible to phagocytosis. The bacterium-antibody complex then binds the macrophages via the Fc receptor and phagocytosis begins. 

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Low humidity also affects comfort and health. Comfort complaints about dry nose, throat, eyes, and skin occur in low-humidity conditions, typically when the dew point is less than 0 °C. Low humidity can lead to drying of the skin and mucous surfaces. On respiratory surfaces, drying can concentrate mucus to the extent that ciliary clearance and phagocytic activities are re-... 

A class of immunoregulatory polypeptides produced by various cells types, but predominantly by mononuclear phagocytes activated by signals provided by exogenous pyrogens. These peptides act as endogenous pyrogens. 

Colchicine has a long history of successful use and was the treatment of choice for many years. It is used infrequently today because of its low therapeutic index. Colchicine is thought to exert its anti-inflammatory effects by interfering with the function of mitotic spindles in neutrophils by binding of tubulin dimers this inhibits phagocytic activity. 

Additional molecular mechanisms must also mediate IFN-y effects, as it promotes a marked clinical improvement in some CGD patients without enhancing phagocyte activity. IFN-y s demonstrated ability to stimulate aspects of cellular and humoral immunity (e.g. via T- and B-lymphocytes), as well as NK cell activity, is most likely responsible for these observed improvements. 

Additional studies illustrate that IFN-y stimulates phagocytic activity in humans suffering from various cancers, AIDS and lepromatous leprosy (leprosy is caused by the bacterium Mycobacterium leprae. Lepromatous leprosy is a severe contagious form of the disease leading to disfigurement). IFN-y may thus prove useful in treating such conditions. 

Non-specific immunity Peritoneal macrophage count and phagocytic activity Phagocytosis... 

Fournier M, et al., Effects of exposure of My a arenaria and Mactmmeris polynyma to contaminated marine sediments on phagocytic activity of hemocytes, Aquatic Toxicol., 59, 89,2002. 

Russo, J. and Lagidick, L., Effects of environmental concentrations of atrazine on hemocyte density and phagocytic activity of pond snails Lymnea stagnalis, Environ. Pollut., 127, 303, 2004. 

Seeley, K.R., andWeeks-Perkins, B.A., Altered phagocytic activity of macrophages in oyster toadfish from a highly polluted subestuary, J. Aquat. Animal Health, 3, 224, 1991. 

Pillet, S. et al., In vitro exposure of seal peripheral blood leukocytes to different metals reveal a sex-dependent effect of zinc on phagocytic activity, Mar. Pollut. Bull., 40,921,2000. 

Garland, L. G. (1992). New pathways of phagocyte activation The coupling of receptor-linked phospholipase D and the role of tyrosine kinase in primed neutrophils. FEMS Microbiol. Immunol. 105,229-38. 

Sakai H, Horinouchi H, Tomiyama K, et al. Hemoglobin-vesicles as oxygen carriers influence on phagocytic activity and histopathological changes in reticuloendothelial system. Am J Pathol 2001 159 1079. 

A variety of assays have been developed to quantify phagocytic activity. These include direct microscopic visualization (2,3), spectrophotometric evaluation of phagocytized paraffin droplets containing dye (4), scintillation counting of radiolabeled bacteria (5), fluorometric (6), and flow cytometric analysis of fluorescent particles (7-13). The flow cytometric assay offers the advantage of rapid analysis of thousands of cells and quantification of the internalized particle density for each analyzed cell. The assay may be performed with purified leukocyte preparations (7-13) or anficoagulated whole blood (14,15). 

Not all KCs are phagocytic to the same extent periportal KCs generally have a higher level of phagocytic activity than those in other regions of the liver [49]. Prior to phagocytosis, particulate material like viruses, bacteria and erythrocytes may be opsonized and bound by specific receptors, but this is not essential for phagocytosis [50]. 

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