Multiple Risk Factor Intervention Trial (MRFIT)
- PDF / 1,188,467 Bytes
- 98 Pages / 504.57 x 720 pts Page_size
- 109 Downloads / 163 Views
Macrophages Riyad Khanfer School of Sport and Exercise Sciences, The University of Birmingham, Edgbaston, Birmingham, UK
Definition Macrophages are white blood cells which form an important part of the innate immunity (non-specific). They are widely distributed in the body’s tissues. Macrophages have irregular shape with granules in their cytoplasm. They are phagocytes and play a crucial role in the initiation of the adaptive (specific) immune response. They engulf, remove, and digest necrotic cell debris, bacteria, and other foreign bodies and also play important roles in the early phases of infection and inflammation (Levinson 2006; Waugh and Grant 2001). Known as antigen-presenting cells, macrophages migrate between tissues, and when they encounter pathogen/antigen, they engulf it, more importantly, they digest the antigen via specific intracellular processes and transport the most antigenic fragment to their own cell membrane and display it on their surface, where they carry it until they come into contact with the adaptive immune cells (T lymphocytes) in the lymphoid tissues. These lymphocytes become activated and sensitized as a result and eventually proliferate
and differentiate into three main types of memory T cells which generate a specific memory against this particular original antigen (Janway et al. 2005). In the inflammatory response, macrophages produce many cytokines (cell messengers); among them are two important proinflammatory cytokines: interferon-g and tumor necrosis factor (TNF). Macrophages have also been found to play a role in tumor immunology; they can infiltrate tumor mass and destroy tumor cells in tissue culture by producing reactive oxygen intermediates (ROIs) and tumor necrosis factor (TNF) (Janway et al. 2005; Weinberg 2007).
Cross-References ▶ Immune Function
References and Readings Janeway, C. A., Travers, P., Walport, M., & Shlomchik, M. J. (2005). Immunobiology (6th ed.). New York/ London: Garland Science. Levinson, W. (2006). Review of medical microbiology and immunology (9th ed.). New York: McGraw-Hill Medical. Waugh, A., & Grant, A. (2001). Ross and Wilson anatomy and physiology in health and illness. Edinburgh: Churchill Livingstone. Weinberg, R. (2007). The Biology of Cancer. New York: Garland Science.
M.D. Gellman & J.R. Turner (eds.), Encyclopedia of Behavioral Medicine, DOI 10.1007/978-1-4419-1005-9, # Springer Science+Business Media New York 2013
M
1184
Magnetic Resonance Imaging (MRI) John Ryan1 and Howard Aizenstein2 1 Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh, Pittsburgh, PA, USA 2 Geriatric Psychiatry Neuroimaging, Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
Synonyms MRI
Definition Magnetic resonance imaging is a noninvasive imaging method used for visualizing structures in the body. The participant is placed in a strong static magnetic field that aligns all atomic nuclei in the body. A radiofrequency pulse is applied at a resonant frequency to selectively
Data Loading...
