Phagocytic ability

The neutrophils (also called polymorphonuclear leucocytes, PMNs), which are the professional phagocytes of the body. They constitute >70% of the total leucocyte population, remaining in the circulatory system for less than 48 hours before migrating into the tissues, in response to a suitable stimulus, where they phagocytose material. They possess receptors forFc and activated C3 which enhance their phagocytic ability (see later in chapter). 

Mechanisms by which ozone might interfere with bactericidal function include an alteration in cell-membrane function that produces a loss in phagocytic ability and is perhaps mediated by lipid peroxides and a decrease in the ability of veolar macrophages to kill phagocytized bacteria. Leukocytes in general appear to have a multiplicity of mechanisms for destroying ingested bacteria. 

Table 4.10. Some pathogens (bacterial, fungal and protozoal) whose phagocyte-mediated destruction is impaired in persons suffering from chronic granulomatous disease (CGD). Administration of IFN-y, in most cases, enhances the phagocytes ability to destroy these pathogens. These agents can cause hepatic and pulmonary infections, as well as genitourinary tract, joint and other infections...

Steroids also alter important functional activities of lymphocytes and monocytes. This effect is mainly on T lymphocytes and is at least partly due to a decrease in IL-2 production. Other proinflammatory cytokines such as IL-1 and IL-6 are also down regulated (Barnes, 2001 Krensky et al., 2005). The effect on B lymphocytes is less prominent. Steroids also profoundly impair the function of monocytes/macrophages by significantly decreasing their phagocytic ability. Glucocorticoids also increase I B expression, thereby curtailing activation of NF-kB, which increases apoptosis of activated cells (Auphan etal., 1995). 

Immunological Effects. Very few data are available on the immunological effects of vanadium in humans or animals. One intermediate-duration oral mouse study of sodium orthovanadate showed no immunological damage as measured by a response to sheep erythrocytes (Sharma et al. 1981). Intraperitoneal injections of ammonia metavanadate into mice have caused impairment in response to bacterial challenges also decreased peritoneal macrophage phagocytic ability (Cohen et al. 

CARBALLAL M j, l6pez c, azevedo c, villalba A (1997), In vitro study of phagocytic ability of Mytilus galloprovincialis Lmk. hemocytes. Fish Shellfish Immunol, 7, 403 16. 

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