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Leukocyte-promoting Factor
Leukocyte-promoting factor, more commonly known as leukopoietin, is a category of substances produced by neutrophils when they encounter a foreign antigen. Leukopoietin stimulates the bone marrow to increase the rate of leukopoiesis in order to replace the neutrophils that will inevitably be lost when they begin to phagocytose the foreign antigens. Leukocyte-promoting factors include colony stimulating factors (CSFs) (produced by monocytes and T lymphocytes), interleukins (produced by monocytes, macrophages, and endothelial cells), prostaglandins, and lactoferrin. See also * White blood cell * Leukocytosis * Complete blood count * Indium-111 WBC scan * Leukocyte extravasation Leukocyte extravasation (also commonly known as leukocyte adhesion cascade or diapedesis – the passage of cells through the intact vessel wall) is the movement of leukocytes out of the circulatory system and towards the site of tissue damage or ... References Cytokines Hormones of the blood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrophil Granulocyte
Neutrophils (also known as neutrocytes or heterophils) are the most abundant type of granulocytes and make up 40% to 70% of all white blood cells in humans. They form an essential part of the innate immune system, with their functions varying in different animals. They are formed from stem cells in the bone marrow and differentiated into subpopulations of neutrophil-killers and neutrophil-cagers. They are short-lived and highly mobile, as they can enter parts of tissue where other cells/molecules cannot. Neutrophils may be subdivided into segmented neutrophils and banded neutrophils (or bands). They form part of the polymorphonuclear cells family (PMNs) together with basophils and eosinophils. The name ''neutrophil'' derives from staining characteristics on hematoxylin and eosin ( H&E) histological or cytological preparations. Whereas basophilic white blood cells stain dark blue and eosinophilic white blood cells stain bright red, neutrophils stain a neutral pink. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostaglandin
The prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derived enzymatically from the fatty acid arachidonic acid. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring. They are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives. The structural differences between prostaglandins account for their different biological activities. A given prostaglandin may have different and even opposite effects in different tissues in some cases. The ability of the same prostaglandin to stimulate a reaction in one tissue and inhibit the same reaction in another tissue is determined by the type of receptor to which the prostaglandin binds. They act as autocrine or paracrine factors with their target cells present in the immediate vicinity of the site of their secreti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokines
Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrine signaling, autocrine, paracrine signaling, paracrine and endocrine signaling as Immunomodulation, immunomodulating agents. Cytokines include chemokines, interferons, interleukins, lymphokines, and tumour necrosis factors, but generally not hormones or growth factors (despite some growth factor#cytokine, overlap in the terminology). Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes and mast cells, as well as Endothelium, endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. They act through cell surface receptors and are especially important in the immune system; cytokines modulate the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukocyte Extravasation
Leukocyte extravasation (also commonly known as leukocyte adhesion cascade or diapedesis – the passage of cells through the intact vessel wall) is the movement of leukocytes out of the circulatory system and towards the site of tissue damage or infection. This process forms part of the innate immune response, involving the recruitment of non-specific leukocytes. Monocytes also use this process in the absence of infection or tissue damage during their development into macrophages. Overview Leukocyte extravasation occurs mainly in post-capillary venules, where haemodynamic shear forces are minimised. This process can be understood in several steps: # Chemoattraction # Rolling adhesion # Tight adhesion # (Endothelial) Transmigration It has been demonstrated that leukocyte recruitment is halted whenever any of these steps is suppressed. White blood cells (leukocytes) perform most of their functions in tissues. Functions include phagocytosis of foreign particles, production of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indium-111 WBC Scan
The indium white blood cell scan is a nuclear medicine procedure in which white blood cells (mostly neutrophils) are removed from the patient, tagged with the radioisotope Indium-111, and then injected intravenously into the patient. The tagged leukocytes subsequently localize to areas of relatively new infection. The study is particularly helpful in differentiating conditions such as osteomyelitis from decubitus ulcers for assessment of route and duration of antibiotic therapy. In imaging of infections, the gallium scan has a sensitivity advantage over the indium white blood cell scan in imaging osteomyelitis (bone infection) of the spine, lung infections and inflammation, and in detecting chronic infections. In part, this is because gallium binds to neutrophil membranes, even after neutrophil death, whereas localization of neutrophils labeled with indium requires them to be in relatively good functional order. However, indium leukocyte imaging is better at localizing acute (i.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complete Blood Count
A complete blood count (CBC), also known as a full blood count (FBC), is a set of medical laboratory tests that provide information about the cells in a person's blood. The CBC indicates the counts of white blood cells, red blood cells and platelets, the concentration of hemoglobin, and the hematocrit (the volume percentage of red blood cells). The red blood cell indices, which indicate the average size and hemoglobin content of red blood cells, are also reported, and a white blood cell differential, which counts the different types of white blood cells, may be included. The CBC is often carried out as part of a medical assessment and can be used to monitor health or diagnose diseases. The results are interpreted by comparing them to reference ranges, which vary with sex and age. Conditions like anemia and thrombocytopenia are defined by abnormal complete blood count results. The red blood cell indices can provide information about the cause of a person's anemia such as iron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukocytosis
Leukocytosis is a condition in which the white cell (leukocyte count) is above the normal range in the blood. It is frequently a sign of an inflammatory response, most commonly the result of infection, but may also occur following certain parasitic infections or bone tumors as well as leukemia. It may also occur after strenuous exercise, convulsions such as epilepsy, emotional stress, pregnancy and labor, anesthesia, as a side effect of medication (e.g., lithium), and epinephrine administration. There are five principal types of leukocytosis: # Neutrophilia (the most common form) # Lymphocytosis # Monocytosis # Eosinophilia # Basophilia This increase in leukocyte (primarily neutrophils) is usually accompanied by a "left upper shift" in the ratio of immature to mature neutrophils and macrophages. The proportion of immature leukocytes increases due to proliferation and inhibition of granulocyte and monocyte precursors in the bone marrow which is stimulated by several products of i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Blood Cell
White blood cells, also called leukocytes or leucocytes, are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell lineage (myeloid cells or lymphoid cells). White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinophils, and basophils), and agranulocytes (monocytes, and lymphocytes (T cells and B cells)). Myeloid cells ( myelocytes) include neutrophils, eosinophils, mast cells, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactoferrin
Lactoferrin (LF), also known as lactotransferrin (LTF), is a multifunctional protein of the transferrin family. Lactoferrin is a globular glycoprotein with a molecular mass of about 80 kDa that is widely represented in various secretory fluids, such as milk, saliva, tears, and nasal secretions. Lactoferrin is also present in secondary granules of PMNs and is secreted by some acinar cells. Lactoferrin can be purified from milk or produced recombinantly. Human colostrum (''"first milk"'') has the highest concentration, followed by human milk, then cow milk (150 mg/L). Lactoferrin is one of the components of the immune system of the body; it has antimicrobial activity ( bacteriocide, fungicide) and is part of the innate defense, mainly at mucoses. In particular, lactoferrin provides antibacterial activity to human infants. Lactoferrin interacts with DNA and RNA, polysaccharides and heparin, and shows some of its biological functions in complexes with these ligands. Lact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endothelial Cell
The endothelium is a single layer of squamous endothelial cells that line the interior surface of blood vessels and lymphatic vessels. The endothelium forms an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. Endothelial cells form the barrier between vessels and tissue and control the flow of substances and fluid into and out of a tissue. Endothelial cells in direct contact with blood are called vascular endothelial cells whereas those in direct contact with lymph are known as lymphatic endothelial cells. Vascular endothelial cells line the entire circulatory system, from the heart to the smallest capillaries. These cells have unique functions that include fluid filtration, such as in the glomerulus of the kidney, blood vessel tone, hemostasis, neutrophil recruitment, and hormone trafficking. Endothelium of the interior surfaces of the heart chambers is called endocardium. An impaired function can lead to serious health issues thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antigen
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. The term ''antigen'' originally referred to a substance that is an antibody generator. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of monosaccharides/simple sugars), lipids, or nucleic acids. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react and bind more than one antigen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cells, microbes, cellular debris, and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. The process is called phagocytosis, which acts to defend the host against infection and injury. These large phagocytes are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense ( innate immunity) and also help initiate specific defense mechanisms (adaptive immunity) by recruiting othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
