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Gorham's Disease
Gorham's disease (pronounced GOR-amz), also known as Gorham vanishing bone disease and phantom bone disease, is a very rare skeletal condition of unknown cause, characterized by the uncontrolled proliferation of distended, thin-walled vascular or lymphatic channels within bone, which leads to resorption and replacement of bone with angiomas and/or fibrosis.Gorham LW, Stout AP. Massive osteolysis (acute spontaneous absorption of bone, phantom bone, disappearing bone): its relation to hemangiomatosis. J Bone Joint Surg m1955;37-A:985-1004.Ross JL., Schinella R., and Shenkman L. Massive osteolysis: An unusual cause of bone destruction. The American Journal of Medicine 1978; 65(2): 367-372. Signs and symptoms The symptoms of Gorham's disease vary depending on the bones involved. It may affect any part of the skeleton, but the most common sites of disease are the shoulder, skull, pelvic girdle, jaw, ribs, and spine.MÖLLER, G., Priemel, M., Amling, M. Werner, M., Kuhlmey, A. S., D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Disease
Bone disease refers to the medical conditions which affect the bone. Terminology A bone disease is also called an "osteopathy", but because the term osteopathy is often used to refer to an alternative health-care philosophy, use of the term can cause some confusion. Bone and cartilage disorders Osteochondrodysplasia is a general term for a disorder of the development of bone and cartilage. List A * Ambe * Avascular necrosis or Osteonecrosis * Arthritis B * Bone spur (Osteophytes) C * Craniosynostosis * Coffin–Lowry syndrome * Copenhagen disease F * Fibrodysplasia ossificans progressiva * Fibrous dysplasia * Fong disease (or Nail–patella syndrome) * Fracture G * Giant cell tumor of bone * Greenstick fracture * Gout H * Hypophosphatasia * Hereditary multiple exostoses K * Klippel–Feil syndrome M * Metabolic bone disease * Multiple myeloma N * Nail–patella syndrome O * Osteitis * Osteitis deformans (or Paget's disease of bone) * Osteitis fibr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoclasts
An osteoclast () is a type of bone cell that breaks down bone tissue. This function is critical in the maintenance, repair, and remodeling of bones of the vertebral skeleton. The osteoclast disassembles and digests the composite of hydrated protein and mineral at a molecular level by secreting acid and a collagenase, a process known as ''bone resorption''. This process also helps regulate the level of blood calcium. Osteoclasts are found on those surfaces of bone that are undergoing resorption. On such surfaces, the osteoclasts are seen to be located in shallow depressions called ''resorption bays (Howship's lacunae)''. The resorption bays are created by the erosive action of osteoclasts on the underlying bone. The border of the lower part of an osteoclast exhibits finger-like processes due to the presence of deep infoldings of the cell membrane; this border is called ''ruffled border''. The ruffled border lies in contact with the bone surface within a resorption bay. The peripher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dystrophic Calcification
Dystrophic calcification (DC) is the calcification occurring in degenerated or necrotic tissue, as in hyalinized scars, degenerated foci in leiomyomas, and caseous nodules. This occurs as a reaction to tissue damage, including as a consequence of medical device implantation. Dystrophic calcification can occur even if the amount of calcium in the blood is not elevated (a systemic mineral imbalance would elevate calcium levels in the blood and all tissues) and cause metastatic calcification. Basophilic calcium salt deposits aggregate, first in the mitochondria, then progressively throughout the cell. These calcifications are an indication of previous microscopic cell injury, occurring in areas of cell necrosis when activated phosphatases bind calcium ions to phospholipids in the membrane. Calcification in dead tissue #Caseous necrosis in T.B. is most common site of dystrophic calcification. #Liquefactive necrosis in chronic abscesses may get calcified. #Fat necrosis following acu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atypia
Atypia (from Greek, ''a'' + ''typos'', without type; a condition of being irregular or nonstandard) is a histopathologic term for a structural abnormality in a cell, i.e. it is used to describe atypical cells. Atypia can be caused by an infection or irritation if diagnosed in a Pap smear, for example. In the uterus it is more likely to be precancerous. The related concept of dysplasia refers to an abnormality of development, and includes abnormalities on larger, histopathologic scales. Example features Features that constitute atypia have different definitions for different diseases, but often include the following nucleus abnormalities: *Enlargement *Pleomorphism *Nuclear polychromasia, which means variability in nuclear chromatin content. Polychromasia otherwise refers to a disease of immature red blood cells. *Numerous mitotic figures Examples for Barrett's esophagus In Barrett's esophagus, features that are classified as atypia but not as dysplasia are mainly: *''Nuclear st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is then fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous or inflammatory conditions. History T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphangiomatosis
Lymphangiomatosis is a condition where a lymphangioma is not present in a single localised mass, but in a widespread or multifocal manner. It is a rare type of tumor which results from an abnormal development of the lymphatic system. It is thought to be the result of congenital errors of lymphatic development occurring prior to the 20th week of gestation. Lymphangiomatosis is a condition marked by the presence of cysts that result from an increase both in the size and number of thin-walled lymphatic channels that are abnormally interconnected and dilated.Pernick, Nat. "Soft Tissue Tumors Part 3 Muscle, Vascular, Nerve, Other Lymphangiomatosis." PathologyOutlines.com. PathologyOutlines.com, Inc., 10/17/2009. Web. 6 Sep 2011. http://www.pathologyoutlines.com/topic/softtissue3lymphangiomatosis.html. 75% of cases involve multiple organs. It typically presents by age 20 and, although it is technically benign, these deranged lymphatics tend to invade surrounding tissues and cause problem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histopathological
Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Specifically, in clinical medicine, histopathology refers to the examination of a biopsy or surgical specimen by a pathologist, after the specimen has been processed and histological sections have been placed onto glass slides. In contrast, cytopathology examines free cells or tissue micro-fragments (as "cell blocks"). Collection of tissues Histopathological examination of tissues starts with surgery, biopsy, or autopsy. The tissue is removed from the body or plant, and then, often following expert dissection in the fresh state, placed in a fixative which stabilizes the tissues to prevent decay. The most common fixative is 10% neutral buffered formalin (corresponding to 3.7% w/v formaldehyde in neutral buffered water, such as phosphate buff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascularization
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting. Vasculogenesis is the embryonic formation of endothelial cells from mesoderm cell precursors, and from neovascularization, although discussions are not always precise (especially in older texts). The first vessels in the developing embryo form through vasculogenesis, after which angiogenesis is responsible for most, if not all, blood vessel growth during development and in disease. Angiogenesis is a normal and vital process in growth and development, as well as in wound healing and in the formation of granulation tissue. However, it is also a fundamental step in the transition of tumors from a benign state to a malignant one, leading to the use of angiogenesis inhibitors in the treatment of cancer. The essential role of angiogenesis in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autocrine
Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger (called the autocrine agent) that binds to autocrine receptors on that same cell, leading to changes in the cell. This can be contrasted with paracrine signaling, intracrine signaling, or classical endocrine signaling. Examples An example of an autocrine agent is the cytokine interleukin-1 in monocytes. When interleukin-1 is produced in response to external stimuli, it can bind to cell-surface receptors on the same cell that produced it. Another example occurs in activated T cell lymphocytes, i.e., when a T cell is induced to mature by binding to a peptide: MHC complex on a professional antigen-presenting cell and by the B7:CD28 costimulatory signal. Upon activation, "low-affinity" IL-2 receptors are replaced by "high-affinity" IL-2 receptors consisting of α, β, and γ chains. The cell then releases IL-2, which binds to its own new IL-2 receptors, causing self-stimulation an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paracrine
Paracrine signaling is a form of cell signaling, a type of cellular communication in which a cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells. Signaling molecules known as paracrine factors diffuse over a relatively short distance (local action), as opposed to cell signaling by endocrine factors, hormones which travel considerably longer distances via the circulatory system; juxtacrine interactions; and autocrine signaling. Cells that produce paracrine factors secrete them into the immediate extracellular environment. Factors then travel to nearby cells in which the gradient of factor received determines the outcome. However, the exact distance that paracrine factors can travel is not certain. Although paracrine signaling elicits a diverse array of responses in the induced cells, most paracrine factors utilize a relatively streamlined set of receptors and pathways. In fact, different organs in the body - even between different spec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteolysis
Osteolysis is an active resorption of bone matrix by osteoclasts and can be interpreted as the reverse of ossification. Although osteoclasts are active during the natural formation of healthy bone the term "osteolysis" specifically refers to a pathological process. Osteolysis often occurs in the proximity of a prosthesis that causes either an immunological response or changes in the bone's structural load. Osteolysis may also be caused by pathologies like bone tumors, cysts, or chronic inflammation. Joint replacement While bone resorption is commonly associated with many diseases or joint problems, the term ''osteolysis'' generally refers to a problem common to artificial joint replacements such as total hip replacements, total knee replacements and total shoulder replacements. Osteolysis can also be associated with the radiographic changes seen in those with bisphosphonate-related osteonecrosis of the jaw. There are several biological mechanisms which may lead to osteolysis. In t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vascular Endothelial Growth Factor
Vascular endothelial growth factor (VEGF, ), originally known as vascular permeability factor (VPF), is a signal protein produced by many cells that stimulates the formation of blood vessels. To be specific, VEGF is a sub-family of growth factors, the platelet-derived growth factor family of cystine-knot growth factors. They are important signaling proteins involved in both vasculogenesis (the '' de novo'' formation of the embryonic circulatory system) and angiogenesis (the growth of blood vessels from pre-existing vasculature). It is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate such as in hypoxic conditions. Serum concentration of VEGF is high in bronchial asthma and diabetes mellitus. VEGF's normal function is to create new blood vessels during embryonic development, new blood vessels after injury, muscle following exercise, and new vessels (collateral circulation) to bypass blocked vessels. It can contribute to disease. So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
