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Haemotoxin
Hemotoxins, haemotoxins or hematotoxins are toxins that destroy red blood cells, disrupt blood clotting, and/or cause organ degeneration and generalized tissue damage. The term ''hemotoxin'' is to some degree a misnomer since toxins that damage the blood also damage other tissues. Injury from a hemotoxic agent is often very painful and can cause permanent damage and in severe cases death. Loss of an affected limb is possible even with prompt treatment. Hemotoxins are frequently employed by venomous animals, including snakes (vipers and pit vipers) and spiders (brown recluse). Animal venoms contain enzymes and other proteins that are hemotoxic or neurotoxic or occasionally both (as in the Mojave rattlesnake, the Japanese mamushi, and similar species). In addition to killing the prey, part of the function of a hemotoxic venom for some animals is to aid digestion. The venom breaks down protein in the region of the bite, making prey easier to digest. The process by which a hemotoxin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venom (poison)
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism. Venom has evolved in terrestrial and marine environments and in a wide variety of animals: both predators and prey, and both vertebrates and invertebrates. Venoms kill through the action of at least four major classes of toxin, namely necrotoxins and cytotoxins, which kill cells; neurotoxins, which affect nervous systems; myotoxins, which damage muscles; and haemotoxins, which disrupt blood clotting. Venomous animals cause tens of thousa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxin
A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849–1919) and is derived from the word toxic. Toxins can be small molecules, peptides, or proteins that are capable of causing disease on contact with or absorption by body tissues interacting with biological macromolecules such as enzymes or cellular receptors. Toxins vary greatly in their toxicity, ranging from usually minor (such as a bee sting) to potentially fatal even at extremely low doses (such as botulinum toxin). Toxins are largely secondary metabolites, which are organic compounds that are not directly involved in an organism's growth, development, or reproduction, instead often aiding it in matters of defense. Terminology Toxins are often distinguished from other chemical agents strictly based on their biological origin. Le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxin
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature nervous tissue.Olney 2002 The term can also be used to classify endogenous compounds, which, when abnormally contacted, can prove neurologically toxic. Though neurotoxins are often neurologically destructive, their ability to specifically target neural components is important in the study of nervous systems. Common examples of neurotoxins include lead, ethanol (drinking alcohol), glutamate,Choi 1987 nitric oxide, botulinum toxin (e.g. Botox), tetanus toxin,Simpson 1986 and tetrodotoxin. Some substances such as nitric oxide and glutamate are in fact essential for proper function of the body and only exert neurotoxic effects at excessive concentrations. Neurotoxins inhibit neuron control over ion concentrations across the cell membrane, or com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daboia
''Daboia'' is a genus of venomous vipers.. Species The following four species are recognized as being valid: *''Daboia mauritanica'' – Moorish viper *''Daboia palaestinae'' – Palestine viper *''Daboia russelii'' – Russell's viper *''Daboia siamensis'' – eastern Russell's viper In the future, more species may be added to ''Daboia''. Obst (1983) reviewed the genus and suggested that it be extended to include ''Macrovipera lebetina'', ''Daboia palaestinae'', and '' M. xanthina''. Groombridge (1980, 1986) united ''V. palaestinae'' and ''Daboia'' as a clade based on a number of shared apomorphies In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ..., including snout shape and head color pattern. Lenk et al. (2001) found support for this idea based on molecular evidence, sugge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laboratory
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physicians' offices, clinics, hospitals, and regional and national referral centers. Overview The organisation and contents of laboratories are determined by the differing requirements of the specialists working within. A physics laboratory might contain a particle accelerator or vacuum chamber, while a metallurgy laboratory could have apparatus for casting or refining metals or for testing their strength. A chemist or biologist might use a wet laboratory, while a psychologist's laboratory might be a room with one-way mirrors and hidden cameras in which to observe behavior. In some laboratories, such as those commonly used by computer scientists, computers (sometimes supercomputers) are used for either simulations or the analysis of data. Scient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dilute Russell's Viper Venom Time
Dilute Russell's viper venom time (dRVVT) is a laboratory test often used for detection of lupus anticoagulant (LA). History Russell's viper venom (RVV) was known to clot blood many years ago. It was widely used as a styptic to clot minor wounds when razor blades were more commonly used for shaving (e.g. “Stypven”, Burroughs-Wellcome Pharma). RVV came to be useful in laboratory tests for blood clotting factors V, X, prothrombin and phospholipid. It was first used in clotting tests for lupus anticoagulant (LA) in an individual case in 1975. The “dilute Russells Viper Venom time (dRVVT)” test was then applied in 1985 to diagnose LA in a large number of patients and it became more widely used for this purpose. This multi-step method involved adding individual solutions of dilute phospholipid, RVV and calcium chloride to a test plasma and then measuring how long it took for the mixture to clot. In 1989, researchers at Westmead Hospital developed a simpler assay by combining ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiphospholipid Syndrome
Antiphospholipid syndrome, or antiphospholipid antibody syndrome (APS or APLS), is an autoimmune, hypercoagulable state caused by antiphospholipid antibodies. APS provokes blood clots (thrombosis) in both arteries and veins as well as pregnancy-related complications such as miscarriage, stillbirth, preterm delivery, and severe preeclampsia. Although the exact etiology of APS is still not clear, genetics is believed to play a key role in the development of the disease. The diagnostic criteria require one clinical event (i.e. thrombosis or pregnancy complication) and two positive blood test results spaced at least three months apart that detect lupus anticoagulant, anti-apolipoprotein antibodies, or anti-cardiolipin antibodies. Antiphospholipid syndrome can be primary or secondary. Primary antiphospholipid syndrome occurs in the absence of any other related disease. Secondary antiphospholipid syndrome occurs with other autoimmune diseases, such as systemic lupus erythematosu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coagulation
Coagulation, also known as clotting, is the process by which blood changes from a liquid to a gel, forming a blood clot. It potentially results in hemostasis, the cessation of blood loss from a damaged vessel, followed by repair. The mechanism of coagulation involves activation, adhesion and aggregation of platelets, as well as deposition and maturation of fibrin. Coagulation begins almost instantly after an injury to the endothelium lining a blood vessel. Exposure of blood to the subendothelial space initiates two processes: changes in platelets, and the exposure of subendothelial tissue factor to plasma factor VII, which ultimately leads to cross-linked fibrin formation. Platelets immediately form a plug at the site of injury; this is called ''primary hemostasis. Secondary hemostasis'' occurs simultaneously: additional coagulation (clotting) factors beyond factor VII ( listed below) respond in a cascade to form fibrin strands, which strengthen the platelet plug. Disorders of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Diagnosis
Medical diagnosis (abbreviated Dx, Dx, or Ds) is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as diagnosis with the medical context being implicit. The information required for diagnosis is typically collected from a history and physical examination of the person seeking medical care. Often, one or more diagnostic procedures, such as medical tests, are also done during the process. Sometimes posthumous diagnosis is considered a kind of medical diagnosis. Diagnosis is often challenging because many signs and symptoms are nonspecific. For example, redness of the skin (erythema), by itself, is a sign of many disorders and thus does not tell the healthcare professional what is wrong. Thus differential diagnosis, in which several possible explanations are compared and contrasted, must be performed. This involves the correlation of various pieces of information followed by the recognition and differentiat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gloydius Blomhoffii
''Gloydius blomhoffii'', commonly known as the mamushi,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . Japanese moccasin, Japanese pit viper, Qichun snake, Salmusa or Japanese mamushi,Gumprecht A, Tillack F, Orlov NL, Captain A, Ryabov S (2004). ''Asian Pitvipers''. First Edition. Berlin: Geitje Books. 368 pp. . is a venomous pit viper species found in Japan. It was once considered to have 4 subspecies, but it is now considered monotypic. This species, along with the yamakagashi (''Rhabdophis tigrinus'') and the Okinawan habu (''Protobothrops flavoviridis''), are the most venomous snakes in Japan. Every year, 2000–3000 people in Japan are bitten by a mamushi. Bitten victims typically require one week of treatment in a hospital. Severe bites require intensive care, and approximately 10 victims die annually. Etymology The specific name, ''blomhoffii'', is in honor of Jan Cock Blomhoff, who was director of the Dutch trading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crotalus Scutulatus
''Crotalus scutulatus'' (common names: Mojave rattlesnake,Crothier, B.I. ''et al''. 2003. Scientific and standard English names of amphibians and reptiles of North America north of Mexico: Update. ''Herpetological Review'' 34:196–203 Stebbins, R.C. 2003. ''A Field Guide to Western Reptiles and Amphibians''. Boston: Houghton Mifflin & Co.Campbell JA, Lamar WW. 2004. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates, Ithaca and London. 870 pp. 1500 plates. . Mojave green,) is a highly venomous pit viper species found in the deserts of the southwestern United States and central Mexico. It is perhaps best known for its potent neurotoxic-hemotoxic venom, which is considered one of the world's most potent rattlesnake venoms. Two subspecies are recognized, including the nominate subspecies described here. Description This species grows to an average of less than in length, with a maximum of . The color varies from shades of brown to pale green depe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
