|
Normoblast
A nucleated red blood cell (NRBC), also known by several other names, is a red blood cell that contains a cell nucleus. Almost all vertebrate organisms have hemoglobin-containing cells in their blood, and with the exception of mammals, all of these red blood cells are nucleated. In mammals, NRBCs occur in normal development as precursors to mature red blood cells in erythropoiesis, the process by which the body produces red blood cells. NRBCs are normally found in the bone marrow of humans of all ages and in the blood of fetuses and newborn infants. After infancy, RBCs normally contain a nucleus only during the very early stages of the cell's life, and the nucleus is ejected as a normal part of cellular differentiation before the cell is released into the bloodstream. The presence of circulating NRBCs in adults occurs in situations of hematopoietic stress such as severe infection, massive hemorrhage, marrow infiltration, or extramedullary hematopoiesis. That is, if NRBCs are ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pronormoblast
A proerythroblast (or rubriblast, or pronormoblast) is a precursor cell to the normoblast (nucleated red blood cell), as the earliest of four stages in its Cellular differentiation, development. In histology, it is very difficult to distinguish it from the other "-blast" cells (lymphoblast, myeloblast, monoblast, and megakaryoblast). The cytoplasm is blue in an H&E stain, indicating that it is basophilic. Proerythroblasts arise from the CFU-e (colony-forming unit Red blood cell, erythroid) cells, and give rise to basophilic erythroblasts. In the mouse, proerythroblasts are large committed Progenitor cell, progenitors that express high levels of transferrin receptor (iron acquisition receptor), the erythropoietin receptor (EpoR), some Stem cell factor#c-KIT receptor, c-Kit (stem cell factor receptor), and are Ter119 (Cell adhesion molecule, cell surface molecule)-positive. Their proliferative capacity is more limited compared to the preceding stage, the CFU-e. In vivo, starting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proerythroblast
A proerythroblast (or rubriblast, or pronormoblast) is a precursor cell to the normoblast (nucleated red blood cell), as the earliest of four stages in its development. In histology, it is very difficult to distinguish it from the other "-blast" cells (lymphoblast, myeloblast, monoblast, and megakaryoblast). The cytoplasm is blue in an H&E stain, indicating that it is basophilic. Proerythroblasts arise from the CFU-e (colony-forming unit erythroid) cells, and give rise to basophilic erythroblasts. In the mouse, proerythroblasts are large committed progenitors that express high levels of transferrin receptor (iron acquisition receptor), the erythropoietin receptor (EpoR), some c-Kit (stem cell factor receptor), and are Ter119 ( cell surface molecule)-positive. Their proliferative capacity is more limited compared to the preceding stage, the CFU-e. In vivo, starting with the proerythroblast stage, erythroid cells undergo several more cell divisions while at the same tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleated Red Cells
The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long strands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene expression. Because the nuclear envelope is impermeab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelofibrosis
Primary myelofibrosis (PMF) is a rare bone marrow blood cancer. It is classified by the World Health Organization (WHO) as a type of myeloproliferative neoplasm, a group of cancers in which there is activation and growth of mutated cells in the bone marrow. This is most often associated with a somatic mutation in the '' JAK2'', '' CALR'', or '' MPL'' genes. In PMF, the bony aspects of bone marrow are remodeled in a process called osteosclerosis; in addition, fibroblasts secrete collagen and reticulin proteins that are collectively referred to as fibrosis. These two pathological processes compromise the normal function of bone marrow, resulting in decreased production of blood cells such as erythrocytes (red cells), granulocytes, and megakaryocytes. The latter are responsible for the production of platelets. Signs and symptoms include fever, night sweats, bone pain, fatigue, and abdominal pain. Increased infections, bleeding and an enlarged spleen ( splenomegaly) are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyponymy And Hypernymy
Hypernymy and hyponymy are the wikt:Wiktionary:Semantic relations, semantic relations between a generic term (''hypernym'') and a more specific term (''hyponym''). The hypernym is also called a ''supertype'', ''umbrella term'', or ''blanket term''. The hyponym names a subset, subtype of the hypernym. The semantic field of the hyponym is included within that of the hypernym. For example, "pigeon", "crow", and "hen" are all hyponyms of "bird" and "animal"; "bird" and "animal" are both hypernyms of "pigeon", "crow", and "hen". A core concept of hyponymy is ''type of'', whereas ''instance of'' is differentiable. For example, for the noun "city", a hyponym (naming a type of city) is "capital city" or "capital", whereas "Paris" and "London" are instances of a city, not types of city. Discussion In linguistics, semantics, general semantics, and ontology components, ontologies, hyponymy () shows the relationship between a generic term (hypernym) and a specific instance of it (hyponym ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym
A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all synonyms of one another: they are ''synonymous''. The standard test for synonymy is substitution: one form can be replaced by another in a sentence without changing its meaning. Words may often be synonymous in only one particular sense: for example, ''long'' and ''extended'' in the context ''long time'' or ''extended time'' are synonymous, but ''long'' cannot be used in the phrase ''extended family''. Synonyms with exactly the same meaning share a seme or denotational sememe, whereas those with inexactly similar meanings share a broader denotational or connotational sememe and thus overlap within a semantic field. The former are sometimes called cognitive synonyms and the latter, near-synonyms, plesionyms or poecilonyms. Lexic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Word Sense
In linguistics, a word sense is one of the meanings of a word. For example, a dictionary may have over 50 different senses of the word "play", each of these having a different meaning based on the context of the word's usage in a sentence, as follows: In each sentence different collocates of "play" signal its different meanings. People and computers, as they read words, must use a process called word-sense disambiguationR. Navigli''Word Sense Disambiguation: A Survey'' ACM Computing Surveys, 41(2), 2009, pp. 1-69. to reconstruct the likely intended meaning of a word. This process uses context to narrow the possible senses down to the probable ones. The context includes such things as the ideas conveyed by adjacent words and nearby phrases, the known or probable purpose and register of the conversation or document, and the orientation (time and place) implied or expressed. The disambiguation is thus context-sensitive. Advanced semantic analysis has resulted in a sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoxemia
Hypoxemia (also spelled hypoxaemia) is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia is usually caused by pulmonary disease. Sometimes the concentration of oxygen in the air is decreased leading to hypoxemia. Definition ''Hypoxemia'' refers to the low level of oxygen in arterial blood. Tissue hypoxia refers to low levels of oxygen in the tissues of the body and the term ''hypoxia'' is a general term for low levels of oxygen. Hypoxemia is usually caused by pulmonary disease whereas tissue oxygenation requires additionally adequate circulation of blood and perfusion of tissue to meet metabolic demands. Hypoxemia is usually defined in terms of reduced partial pressure of oxygen (mm Hg) in arterial blood, but also in terms of reduced content of oxygen (ml oxygen per dl blood) or percentage saturation of hemoglobin (the oxygen-binding protein within red blood cells) with oxygen, which is either found singly o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphoma
Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). The name typically refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph nodes, fever, drenching sweats, unintended weight loss, itching, and constantly feeling tired. The enlarged lymph nodes are usually painless. The sweats are most common at night. Many subtypes of lymphomas are known. The two main categories of lymphomas are the non-Hodgkin lymphoma (NHL) (90% of cases) and Hodgkin lymphoma (HL) (10%). Lymphomas, leukemias and myelomas are a part of the broader group of tumors of the hematopoietic and lymphoid tissues. Risk factors for Hodgkin lymphoma include infection with Epstein–Barr virus and a history of the disease in the family. Risk factors for common types of non-Hodgkin lymphomas include autoimmune diseases, HIV/AIDS, infection with human T-lymphotropic virus, immunosuppressant medicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukemia
Leukemia ( also spelled leukaemia; pronounced ) is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or '' leukemia cells''. Symptoms may include bleeding and bruising, bone pain, fatigue, fever, and an increased risk of infections. These symptoms occur due to a lack of normal blood cells. Diagnosis is typically made by blood tests or bone marrow biopsy. The exact cause of leukemia is unknown. A combination of genetic factors and environmental (non-inherited) factors are believed to play a role. Risk factors include smoking, ionizing radiation, petrochemicals (such as benzene), prior chemotherapy, and Down syndrome. People with a family history of leukemia are also at higher risk. There are four main types of leukemia—acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL) and chronic myelo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myeloma
Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. Often, no symptoms are noticed initially. As it progresses, bone pain, anemia, renal insufficiency, and infections may occur. Complications may include hypercalcemia and amyloidosis. The cause of multiple myeloma is unknown. Risk factors include obesity, radiation exposure, family history, age and certain chemicals. There is an increased risk of multiple myeloma in certain occupations. This is due to the occupational exposure to aromatic hydrocarbon solvents having a role in causation of multiple myeloma. Multiple myeloma is the result of a multi-step malignant transformation, and almost universally originates from the pre-malignant stage monoclonal gammopathy of undetermined significance (MGUS). As MGUS evolves into MM, another pre-stage of the disease is reached, known as smoldering myeloma (SMM). In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
