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Yessotoxin
Yessotoxins are a group of lipophilic, sulfur bearing polyether toxins that are related to ciguatoxins. They are produced by a variety of dinoflagellates, most notably ''Lingulodinium polyedrum'' and '' Gonyaulax spinifera''. When the environmental conditions encourage the growth of YTX producing dinoflagellates, the toxin(s) bioaccumulate in edible tissues of bivalve molluscs, including mussels, scallops, and clams, thus allowing entry of YTX into the food chain. History The first YTX analog discovered, yessotoxin, was initially found in the scallop species '' Patinopecten yessoensis'' in the 1960s. Since then, numerous yessotoxin analogs have been isolated from shellfish and marine algae (including 45-hydroxyyessotoxin and carboxyyessotoxin). Initially, scientists wrongly classified YTXs in the group of diarrhetic shellfish poisoning (DSP) toxins along the lines of okadaic acid and azaspiracids. These type of toxins can cause extreme gastrointestinal upset and accelerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Okadaic Acid
Okadaic acid, C44H68O13, is a toxin produced by several species of dinoflagellates, and is known to accumulate in both marine sponges and shellfish. One of the primary causes of diarrhetic shellfish poisoning, okadaic acid is a potent inhibitor of specific protein phosphatases and is known to have a variety of negative effects on cells. A polyketide, polyether derivative of a C38 fatty acid, okadaic acid and other members of its family have shined light upon many biological processes both with respect to dinoflagellete polyketide synthesis as well as the role of protein phosphatases in cell growth. History As early as 1961, reports of gastrointestinal disorders following the consumption of cooked mussels appeared in both the Netherlands and Los Lagos. Attempts were made to determine the source of the symptoms, however they failed to elucidate the true culprit, instead implicating a species of microplanctonic dinoflagellates. In the summers of the late 1970s, a series of food po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patinopecten Yessoensis
''Mizuhopecten yessoensis'' (Yesso scallop, giant Ezo scallop) is a species of marine bivalve mollusks in the family Pectinidae, the scallops. Its name Yesso/Ezo refers to its being found north of Japan. Its tissues bioaccumulate algal yessotoxins and are studied extensively. Description The Yesso scallop (''Mizuhopecten yessoensis'') is a cold water marine bivalve species. The valves have a convex center with a smooth exterior shell. On one side it is white and on the other dark brown. Habitat The Yesso scallop is widely distributed along the cold coast of Northern Japan. Scallop cultivation is located in the northern islands of Honshu and Hokkaido, with the Sea of Okhotsk, Saroma Lake and Funka Bay in Hokkaido accounting for more than 80% of the scallop production during the period of 1991 to 2002. Ecology and behavior Temperature plays a key role in the timing of spawning and larvae settlement of the Yesso scallop. Generally, the scallops spawn between May 1 to June ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingulodinium Polyedrum
''Lingulodinium polyedra'' is a species of motile photosynthetic dinoflagellates. ''L. polyedra'' are often the cause of red tides in southern California, leading to bioluminescent displays on beaches at night. Life cycle As part of its life cycle, this species produces a resting stage, a dinoflagellate cyst called '' Lingulodinium machaerophorum'' (synonym '' Hystrichosphaeridium machaerophorum''). This cyst was first described by Deflandre and Cookson in 1955 from the Miocene of Balcombe Bay, Victoria, Australia as: "Shell globular, subsphaerical or ellipsoidal with a rigid membrane, more brittle than deformable, covered with numerous long, stiff, conical, pointed processes resembling the blade of a dagger. Surface of shell granular or punctate." Its stratigraphic range is the Upper Paleocene of eastern USA and Denmark till Recent. Organic-walled dinocyst morphology is shown to be controlled by changes in salinity and temperature in some species, more particularly proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonyaulax Spinifera
''Gonyaulax'' is a genus of dinoflagellates with the type species ''Gonyaulax spinifera'' (Claparède et Lachmann) Diesing. ''Gonyaulax'' belongs to red dinoflagellates and commonly causes red tides. It secretes a poisonous toxin known as "saxitoxin" which causes paralysis in humans. Structure ''Gonyaulax'' is a genus of dinoflagellates that are aquatic organisms with two separate flagella: one extends backward and the other wraps around the cell in a lateral groove helping to keep the organism afloat by rotational motility. The plate formula in the genus ''Gonyaulax'' Diesing was redefined as Po, 3', 2a, 6", 6c, 4-8s, 5'", 1p, 1"". Classification All species are marine, except for one freshwater species, ''Gonyaulax apiculata''. It previously included several species, which are now considered to belong to a separate genus, e.g.: *''Gonyaulax tamarensis'' (now: '' Alexandrium tamarense'') *''Gonyaulax grindleyi'' (now: ''Protoceratium reticulatum'') *''Gonyaulax polyed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azaspiracid
Azaspiracids (AZA) are a group of polycyclic ether marine algal toxins produced by the small dinoflagellate '' Azadinium spinosum'' that can accumulate in shellfish and thereby cause illness in humans. Azaspiracid was first identified in the 1990s following an outbreak of human illness in the Netherlands that was associated with ingestion of contaminated shellfish originating from Killary Harbour, Ireland. To date, over 20 AZA analogues have been identified in phytoplankton and shellfish. Over the last 15 years, AZAs have been reported in shellfish from many coastal regions of western Europe, Northern Africa, South America, and North America. In addition, AZAs have been found in Japanese sponges and Scandinavian crabs. Not surprisingly, the global distribution of AZAs appears to correspond to the apparent wide spread occurrence of ''Azadinium''. Empirical evidence is now available that unambiguously demonstrates the accumulation of AZAs in shellfish via direct feeding on AZA-produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxicity
Neurotoxicity is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the central and/or peripheral nervous system. It occurs when exposure to a substance – specifically, a neurotoxin or neurotoxicant– alters the normal activity of the nervous system in such a way as to cause permanent or reversible damage to nervous tissue. This can eventually disrupt or even kill neurons, which are cells that transmit and process signals in the brain and other parts of the nervous system. Neurotoxicity can result from organ transplants, radiation treatment, certain drug therapies, recreational drug use, and exposure to heavy metals, bites from certain species of venomous snakes, pesticides, certain industrial cleaning solvents, fuels and certain naturally occurring substances. Symptoms may appear immediately after exposure or be delayed. They may include limb weakness or numbness, loss of memory, vision, and/or in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Phosphatase
A protein phosphatase is a phosphatase enzyme that removes a phosphate group from the phosphorylated amino acid residue of its substrate protein. Protein phosphorylation is one of the most common forms of reversible protein posttranslational modification ( PTM), with up to 30% of all proteins being phosphorylated at any given time. Protein kinases (PKs) are the effectors of phosphorylation and catalyse the transfer of a γ-phosphate from ATP to specific amino acids on proteins. Several hundred PKs exist in mammals and are classified into distinct super-families. Proteins are phosphorylated predominantly on Ser, Thr and Tyr residues, which account for 79.3, 16.9 and 3.8% respectively of the phosphoproteome, at least in mammals. In contrast, protein phosphatases (PPs) are the primary effectors of dephosphorylation and can be grouped into three main classes based on sequence, structure and catalytic function. The largest class of PPs is the phosphoprotein phosphatase (PPP) family compr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intraperitoneal
The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesothelium supported by a thin layer of connective tissue. This peritoneal lining of the cavity supports many of the abdominal organs and serves as a conduit for their blood vessels, lymphatic vessels, and nerves. The abdominal cavity (the space bounded by the vertebrae, abdominal muscles, diaphragm, and pelvic floor) is different from the intraperitoneal space (located within the abdominal cavity but wrapped in peritoneum). The structures within the intraperitoneal space are called "intraperitoneal" (e.g., the stomach and intestines), the structures in the abdominal cavity that are located behind the intraperitoneal space are called " retroperitoneal" (e.g., the kidneys), and those structures below the intraperitoneal space are called "subperi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatotoxicity
Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn from the market after approval. The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses (e.g. paracetamol) and sometimes even when introduced within therapeutic ranges (e.g. halothane), may injure the organ. Other chemical agents, such as those used in laboratories and industries, natural chemicals (e.g., microcystins), and herbal remedies (two prominent examples being kava, mechanism unknown, and comfrey, through its pyrrolizidine alkaloid content) can also induce hepatotoxicity. Chemicals that cause liver injury are called hepatotoxins. More than 900 drugs have been implicated in causing liver injury (see LiverTox, ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiotoxicity
Cardiotoxicity is the occurrence of heart dysfunction as electric or muscle damage, resulting in heart toxicity. The heart becomes weaker and is not as efficient in pumping blood. Cardiotoxicity may be caused by chemotherapy (a usual example is the class of anthracyclines) treatment and/or radiotherapy; complications from anorexia nervosa; adverse effects of heavy metals intake; the long-term abuse of or ingestion at high doses of certain strong stimulants such as cocaine; or an incorrectly administered drug such as bupivacaine. One of the ways to detect cardiotoxicity at early stages when there is a subclinical dysfunction is by measuring changes in regional function of the heart using strains. See also * Cardiotoxin III * Batrachotoxin * Heart failure * Drug interaction Drug interactions occur when a drug's mechanism of action is disturbed by the concomitant administration of substances such as foods, beverages, or other drugs. The cause is often the inhibition of the sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipophilic
Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipophilic (translated as "fat-loving" or "fat-liking"), and the axiom that "like dissolves like" generally holds true. Thus lipophilic substances tend to dissolve in other lipophilic substances, but hydrophilic ("water-loving") substances tend to dissolve in water and other hydrophilic substances. Lipophilicity, hydrophobicity, and non-polarity may describe the same tendency towards participation in the London dispersion force, as the terms are often used interchangeably. However, the terms "lipophilic" and "hydrophobic" are not synonymous, as can be seen with silicones and fluorocarbons, which are hydrophobic but not lipophilic. __TOC__ Surfactants Hydrocarbon-based surfactants are compounds that are amphiphilic (or amphipathic), having ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third most abundant metal, after iron and aluminium. The most common calcium compound on Earth is calcium carbonate, found in limestone and the fossilised remnants of early sea life; gypsum, anhydrite, fluorite, and apatite are also sources of calcium. The name derives from Latin ''calx'' "lime", which was obtained from heating limestone. Some calcium compounds were known to the ancients, though their chemistry was unknown until the seventeenth century. Pure calcium was isolated in 1808 via electrolysis of its oxide by Humphry Davy, who named the element. Calcium compounds are widely used in many industries: in foods and ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
