Leukocytes nuclei

Malec et al. (M2) discovered the synthesis of antibacterial proteins and nuclear RNA in isolated leukocyte nuclei. In granulocytes, more than one half of mRNA is unstable, quickly and continuously renewing itself and ensuring protein synthesis (Cl). 

Staining Applications Nucleic acids cells chromatin leukocytes nuclei micronuclei megakaryocyte microorganisms sperms ° hairs ... 

Staining Applications Nucleic acids bacteria cells leukocytes nuclei megakaryoc54es ... 

Staining Applications Cytokines antigen-specific antibody leukocytes nuclei nucleic acids parasites precancerous cells prions hairs " kera-tine fibers ... 

Staining Applications Nucleic acids cells antihodies bacteria leukocytes nuclei megakaryocyte microorganisms peptides pro-teins reticulocytes sperms ... 

Staining Applications Nucleic acids cells " bac-teria " chromatin genes leukocytes nuclei peptides proteins antibodies ... 

The leukocytes classified as agranulocytes contain very few granules in their cytoplasm. In further contrast to granulocytes, these cells have a single, large nonsegmented nucleus. 

Figure 1.1. Electron micrographs of leukocytes (a) neutrophil, showing polymorphic nucleus and numerous cytoplasmic granules (b) eosinophil, showing distinctive granules with crystalline core (c) monocyte, with horseshoe-shaped nucleus (d) small lymphocyte. Magnification x7000.

Neutrophil. A granular leukocyte, having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules. Neutrophils have the properties of chemotaxis adherence to immune complexes, and phagocytosis. 

Blood cells. Blood and the linings of blood vessels may be regarded as a fifth tissue type.135/135a The human body contains 5 x 109 erythrocytes or red blood cells per ml, a total of 2.5 x 1013 cells in the five liters of blood present in the body. Erythrocytes are rapidly synthesized in the bone marrow. The nucleus is destroyed, leaving a cell almost completely filled with hemoglobin. With an average lifetime of 125 days, human red blood cells are destroyed by leukocytes in the spleen and liver. 

The flow of leukocytes was studied in square capillaries fabricated on a Si chip, and sealed with a PDMS or Pyrex cover plate. This capillary size (cross section of 4 pm2) is similar to the diameter of a human blood capillary, but is less than both the average diameter of a leukocyte cell (10 pm) and its nucleus (6 pm). Figure 8.32 shows the difference in the flow behavior of two leukocytes (possibly neutrophils) [1175]. Deformation-induced release of ATP from erythrocytes in PDMS channels was studied. The released ATP was detected by chemiluminescence using the luciferin/luciferase system [169]. 

The adrenal corticosteroids have been extensively used to suppress many different aspects of the immune response. AU of the corticosteroids have similar mechanisms of action. They bind to specific corticosteroid binding proteins in the cytoplasm. These complexes are then transported into the nucleus where they bind to discrete portions of the cell s DNA. This binding results in derepression of regulatory genes and the subsequent transcription of new mRNA (Rhen and Cidlowski, 2005). Steroids inhibit the consequences of the immune response. They have several different actions in this regard. One of their most important effects is to transiently alter the number of circulating leukocytes. There is a rapid increase in the number of neutrophils and a concomitant decrease in the number of lymphocytes, monocytes, eosinophils and basophils (Krensky et al, 2005). 

It is now well established that the MCI receptor mainly expressed in melanocytes and leukocytes plays a key role in skin pigmentation and inflammatory response (136, 137). The MC2 receptor is expressed only in the adrenal gland and mediates glucocorticoneogen-esis (123). The MC3 and MC4 receptors are both found in the brain, the MC3 receptor is found in the arcuate nucleus and the nucleus of the solitary tract, whereas the MC4 receptor is mainly found in the hypothalamus (138). Finally, the MC5 receptor is involved in exocrine functions and is localized predominantly in the sebaceous glands (139). The complex role of the melanotropins and the MC receptors, in controlling various physiological functions, has made it difficult to draw simple correlations between these receptors and the... 

Inflammation is induced by the release of proinflammatory mediators from the cytosol of damaged or infected cells (Sect. 13.2.2). One of the first identified cytokines was an osteoclast activation factor later found to induce a multitude of other proinflammatory events, InterLeukin-1 (IL-1). A second was Tumor Necrosis Factor (TNF), more formally known as tumor necrosis factor-alpha, TNF-a (Sect. 13.2.2). The binding of these proteins to receptors on adjacent cells activates Nuclear Factor kappa B (NFkB), a protein in the leukocyte cytosol. The hgand-bound receptor indirectly phosphorylates an NFkB partner protein (Inhibitor of NFkB, IkB) in the cytosol. The phosphorylated IkB is targeted for destruction and its loss exposes a nuclear locahzation sequence on the NFkB protein which can now enter the nucleus where it induces the expression of important proteins, depending on the type of cell that is activated. ODAR is a Receptor Activator of Nuclear Factor kappa B (RANK), one of a large family of proinflammatory hgand receptors on leukocytes. 

Monocyte. Bone marrow-derived mononuclear phagocytic leukocyte, with bean-shaped nucleus and fine granular cytoplasm containing lysosomes, phagocytic vacuoles, and cytoskeletal filaments. Once transported to tissues, monocytes develop into macrophages. 

Some cell types differ sufficiently In density that they can be separated on the basis of this physical property. White blood cells (leukocytes) and red blood cells (erythrocytes), for instance, have very different densities because erythrocytes have no nucleus thus these cells can be separated by equilibrium density centrifugation (described shortly). Because most cell types cannot be differentiated so easily, other techniques such as flow cytometry must be used to separate them. 

The leukocytes can be classified either as polymorphonuclear leukocytes (granulocytes) or mononuclear leukocytes, depending on the morphology of the nucleus in these cells. The mononuclear leukocyte has a rounded nucleus, whereas the polymorphonuclear leukocytes have a multilobed nucleus. 

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