Necrosis (in Greek Νεκρός = Dead) is the name given to accidental death of cells and living tissue. Toxicology (from the Greek words toxicos and logos) is the study of the adverse effects of Chemicals on living organisms Forensic toxicology is the use of Toxicology and other disciplines such as Analytical chemistry, Pharmacology and Clinical chemistry to aid medicolegal Toxinology is the specialized area of Toxicology that deals specifically with animal plant and microbial toxins but is also considered a science in its own right The history of Poison stretches from before 4500 BC to the Present day. S00-T14 - Injury (S00-S09 Head ( Superficial Injury of head ( Superficial injury of 17 Injury and poisoning (800-999 fracture of skull (800-804 ( Fracture of Vault of skull ( Fracture of Base of skull In the context of Biology, poisons are substances that can cause damage, Illness, or Death to Organisms usually by This article is about the class of Biotoxins For other uses see Venom (disambiguation and Venomous (disambiguation. A toxicant is a chemical compound that has an effect on organisms An antidote or counterdose is a substance which can counteract a form of Poisoning. Acceptable daily intake or ADI is a measure of the amount of a specific substance (usually a Food additive, or a residue of a veterinary drug or pesticide in Acute toxicity describes the adverse effects of a substance which result either from a single exposure or from multiple exposures in a short space of time (usually less than 24 hours Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at ftudruinsubstance is lost Biomagnification, also known as bioamplification, or biological magnification is the increase in concentration of a substance such as the Pesticide Fixed Dose Procedure (FDP proposed in 1984 is a method to assess a substance's acute oral Toxicity. In Toxicology, the median lethal dose, LD50 (abbreviation for “Lethal Dose 50%” or LCt50 (Lethal Concentration & Time of a A lethal dose (LD is an indication of the Lethality of a given substance or type of Radiation. Toxic capacity can mean the Toxicity of a substance possibly in relation to a specific Organism and toxic capacity can mean the capacity of an organism Toxicity Class refers to a classification system for Pesticides created by a national or international government-related or -sponsored organization A toxin ( Greek:, toxikon, lit (poison for use on arrows is a Poisonous substance produced by living cells or organisms that is active at very low This article is about the class of Biotoxins For other uses see Venom (disambiguation and Venomous (disambiguation. A neurotoxin is a Toxin that acts specifically on nerve cells ( Neurons, usually by interacting with Membrane proteins such as Ion channels Necrosis (in Greek Νεκρός = "dead" is the name given to unnatural Death of cells and living tissue. Hemotoxins, haemotoxins or hematotoxins are Toxins that destroy Red blood cells (that is cause Hemolysis) disrupt Blood Mycotoxin (from the Greek μύκης (mykes mukos "fungus" is a Toxin produced by an organism of the Fungus kingdom which includes Mushrooms Aflatoxins are naturally occurring Mycotoxins that are produced by many species of Aspergillus, a Fungus, most notably Aspergillus Phototoxins are Toxins that can cause allergic reactions in particularly susceptible individuals and which can cause dangerous Photosensitivity in a much broader range This is a list of toxins poisons and chemical weapons from works of fiction (usually in Fantasy and Science fiction) The Bradford sweets poisoning was the accidental Arsenic poisoning of more than 200 people in Bradford, England in 1858 an estimated 20 people died when sometimes referred to as, is a neurological syndrome caused by severe Mercury poisoning. is a Neurological syndrome caused by severe Mercury poisoning. Alexander Litvinenko was a former officer of Russian Federal Security Service, who escaped prosecution in Russia and received a Political asylum in The Bhopal disaster was an Industrial disaster that occurred in the city of Bhopal, Madhya Pradesh, India, resulting in the immediate deaths The 2007 pet food recalls comprise the contamination and wide recall of many brands of cat and dog foods beginning in March 2007 and the ensuing developments This is a list of Poisonings in chronological order of victim Toxic metals are Metals that form Poisonous soluble compounds and have no biological role i Lead poisoning (also known as saturnism, plumbism, or painter's colic) is a medical condition caused by increased levels of the metal Lead in Mercury poisoning (also known as mercurialism, hydrargyria, Hunter-Russell syndrome, or acrodynia when affecting children is a Disease Cadmium has no constructive purpose in the Human body It and its compounds are extremely Toxic even in low concentrations and will Bioaccumulate in Antimony (IPA (Received Pronunciation, /ˈæntɪmoʊni/ (US is a Chemical element with the symbol Sb (stibium meaning "mark" and Arsenic Poisoning kills by Allosteric inhibition of essential metabolic Enzymes, leading to death from multi-system Beryllium (bəˈrɪliəm is a Chemical element with the symbol Be and Atomic number 4 Iron poisoning is caused by a large excess of Iron intake It has been primarily been associated with young children who consumed large quantities of iron supplement pills Thallium (ˈθæliəm is a Chemical element with the symbol Tl and Atomic number 81 In high concentrations soluble Fluoride Salts are somewhat Toxic. Oxygen toxicity or oxygen toxicity syndrome (also known as the " Paul Bert effect" or the "Lorrain Smith effect" describes harmful effects caused There are four syndromes called shellfish poisoning, which share some common features and are primarily associated with bivalve molluscs (such as Mussels Paralytic shellfish poisoning (PSP is one of the four recognized syndromes of Shellfish poisoning (the others being Neurotoxic shellfish poisoning, diarrhetic Diarrhetic shellfish poisoning (DSP is one of the four recognised symptom types of Shellfish poisoning, the others being Paralytic shellfish poisoning, Neurotoxic Amnesic shellfish poisoning (ASP is a human illness caused by consumption of the marine biotoxin called Domoic acid. Ciguatera is a Foodborne illness poisoning in humans caused by eating Marine species whose flesh is contaminated with a toxin known as Ciguatoxin, Scombroid food poisoning is a foodborne Illness that results from eating spoiled (decayed Fish. Tetrodotoxin (anhydrotetrodotoxin 4-epitetrodotoxin tetrodonic acid TTX is a potent Neurotoxin with no known antidote which blocks Action potentials in Nerves Pesticide Poisonings occur when chemicals intended to control a pest affect non-target organisms such as Humans Wildlife, or Bees Since Many Organophosphates are potent Neurotoxins functioning by inhibiting the action of Acetylcholinesterase (AChE in nerve cells. Foodborne illness (also foodborne disease) is any Illness resulting from the consumption of food Historically most cases of nicotine poisoning have been the result of its use as an Insecticide; however such use is less frequent now than previously Carbon monoxide poisoning occurs after the inhalation of Carbon monoxide gas Vitamin poisoning, or hypervitaminosis, refers to a condition of high storage levels of Vitamins which can lead to Toxic Symptoms The medical The term drug overdose (or simply overdose or OD) describes the Ingestion or application of a Drug or other substance in quantities See also List of deadly fungi Mushroom poisoning, also known as mycetism, refers to deleterious effects from ingestion of Toxic substances present This is a list of Plants containing Poisonous parts that pose a serious risk of illness, injury or Death to Humans or Animals. Hazard symbols are easily recognizable symbols designed to warn about hazardous materials or locations The term carcinogen refers to any substance Radionuclide or radiation that is an agent directly involved in the promotion of Cancer or in the fatation of its propagation In Biology, a mutagen ( Latin, literally origin of change) is a physical or chemical agent that changes the genetic information (usually DNA) This is a list of Extremely Hazardous Substances as defined by Section 302 of the U Biological warfare (BW — known as a germ warfare, biological weapons and bioweaponry — is the use of any Pathogen ( Bacterium Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Death is the termination of the biological functions that define living Organisms It refers both to a specific The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called Tissue is a cellular organizational level intermediate between cells and a complete organism It begins with cell swelling, chromatin digestion, and disruption of the plasma membrane and organelle membranes. Chromatin is the complex basis of DNA and protein that makes up Chromosomes It is found inside the nuclei of eukaryotic cells, and within the The cell membrane (also called the plasma membrane, plasmalemma, or "phospholipid bilayer" is a Selectively permeable Lipid bilayer In Cell biology, an organelle (pronunciation /ɔː(rgəˡnɛl/ is a specialized subunit within a cell that has a specific function and is usually separately enclosed Late necrosis is characterized by extensive DNA hydrolysis, vacuolation of the endoplasmic reticulum, organelle breakdown, and cell lysis. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions The endoplasmic reticulum (Greek endo = "within" (prefix plásma = "formed entity" Latin reticulum = "little net" or ER, is an Organelle Lysis ( Greek, lysis from lyein = to separate refers to the death of a cell by breaking of the cellular membrane often by viral or osmotic The release of intracellular content after plasma membrane rupture is the cause of inflammation in necrosis. Inflammation ( Latin, inflamatio, to set on fire is the complex biological response of vascular tissues to harmful stimuli such as Pathogens

In contrast to apoptosis, cleanup of cell debris by phagocytes of the immune system is generally more difficult, as the disorderly death generally does not send cell signals which tell nearby phagocytes to engulf the dying cell. Phagocytes are cells that are found in the blood bone marrow and other tissues of Vertebrates. An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor In Biology, signal transduction refers to any process by which a cell converts one kind of signal or stimulus into another Phagocytosis is the cellular process of engulfing solid particles by the Cell membrane to form an internal Phagosome, or "food vacuole This lack of signaling makes it harder for the immune system to locate and recycle dead cells which have died through necrosis than if the cell had undergone apoptosis. An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor

Causes

There are many causes of necrosis including prolonged exposure to injury, infection, cancer, infarction, poisons, and inflammation. Injury or bodily injury is Damage or Harm caused to the Structure or function of the Body caused by an outside agent or An infection is the detrimental Colonization of a host Organism by a foreign Species. Cancer (medical term Malignant Neoplasm) is a class of Diseases in which a group of cells display uncontrolled In Medicine, an infarction is the process resulting in a Macroscopic area of necrotic tissue in some organ caused by loss of adequate Blood supply In the context of Biology, poisons are substances that can cause damage, Illness, or Death to Organisms usually by Inflammation ( Latin, inflamatio, to set on fire is the complex biological response of vascular tissues to harmful stimuli such as Pathogens Severe damage to one essential system in the cell leads to secondary damage to other systems, a so-called "cascade of effects". Necrosis can arise from lack of proper care to a wound site. Necrosis is accompanied by the release of special enzymes, that are stored by lysosomes, which are capable of digesting cell components or the entire cell itself. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Lysosomes are Organelles that contain Digestive enzymes (acid Hydrolases. The injuries received by the cell may compromise the lysosome membrane, or may initiate a disorganised chain reaction which causes the release in enzymes. Unlike apoptosis, cells that die by necrosis may release harmful chemicals that damage other cells. In biopsy, necrosis is halted by fixation or freezing. A biopsy (in Greek: βίος life and όψη look/appearance is a Medical test involving the removal of cells or tissues In the fields of Histology, Pathology, and Cell biology, fixation is a chemical process by which Biological tissues are preserved from decay Many species of viper (eg rattlesnakes or Bothrops) produce venom which causes severe necrosis in snake-bite victims. VIPeR is a Military robot developed by the Israeli company Elbit Systems and intended for use in warfare Rattlesnakes are a group of venomous Snakes, genera Crotalus and Sistrurus. Common names: lanceheads American lanceheads American lance-headed vipers This article is about the class of Biotoxins For other uses see Venom (disambiguation and Venomous (disambiguation. Additionally, some spiders (eg the Brown Recluse) contain venom which may cause significant cutaneous injuries with tissue loss and necrosis. The brown recluse Spider, Loxosceles reclusa, is a well-known member of the family Sicariidae (formerly placed in a family "Loxoscelidae"

Severe tissue necrosis following Bothrops asper envenomation. Common names: terciopelo fer-de-lance ( more) Bothrops asper is a venomous pitviper Species The victim was an 11-year old boy, bitten two weeks earlier in Ecuador, but treated only with antibiotics. For a topic outline on this subject see List of basic Ecuador topics. In modern usage an antibiotic is a Chemotherapeutic agent with activity against Microorganisms such as Bacteria, fungi or Protozoa ^[1]

Morphologic patterns

There are seven distinctive morphologic patterns of necrosis:

• Coagulative necrosis is typically seen in hypoxic environments (e. Coagulative Necrosis is a type of accidental cell Death typically caused by Ischemia or Infarction. Chronic Hypoxia is a pathological condition in which the body as a whole ( generalized hypoxia) or region of the body ( tissue hypoxia) is deprived of adequate g. myocardial infarction, infarct of the spleen). Myocardial infarction ( MI or AMI for acute myocardial infarction) also known as a heart attack, occurs when the blood supply The spleen is an organ found in all Vertebrate animals In humans the spleen is located in the abdomen of the body where it functions in the destruction of redundant Red Cell outlines remain after cell death and can be observed by light microscopy. Microscopy is the technical field of using microscopes to view samples or objects
• Liquefactive necrosis is usually associated with cellular destruction and pus formation (e. Liquefactive necrosis (or colliquative necrosis) is a type of Necrosis which is characteristic of focal Bacterial or Fungal infections Pus is a whitish-yellow yellow or yellow-brown substance produced during Inflammatory responses of the body that can be found in regions of Pyogenic bacterial g. pneumonia). Pneumonia is an inflammatory illness of the Lung. Frequently it is described as lung Parenchyma / alveolar inflammation and abnormal This is typical of bacterial or, sometimes, fungal infections because of their ability to stimulate an inflammatory reaction. Curiously, ischemia (restriction of blood supply) in the brain produces liquefactive rather than coagulative necrosis, this is due to the lack of any substantial supportive stroma. In Medicine, ischemia ( Greek ισχαιμία, isch- is restriction hema or haema is Blood) is a restriction
• Gummatous necrosis is restricted to necrosis involving spirochaetal infections (e. The classic lesion is the gumma, a granulomatous lesion thought to be caused by reaction to spirochaete in the tissue Spirochaetes is a phylum of distinctive Gram-negative bacteria, which have long helically coiled cells g. syphilis). Syphilis is a Sexually transmitted disease caused by the spirochetal Bacterium Treponema pallidum pallidum.
• Haemorrhagic necrosis is due to blockage of the venous drainage of an organ or tissue (e. Bleeding, technically known as hemorrhaging / haemorrhaging (see American and British spelling differences) is the loss of Blood from g. in testicular torsion). In testicular torsion the Spermatic cord that provides the blood supply to a Testicle is twisted cutting off the blood supply often causing Orchalgia.
• Caseous necrosis is a specific form of coagulation necrosis typically caused by mycobacteria (e. Caseous necrosis describes a form of Biological tissue death caseous meaning it has a cheese-like appearance g. tuberculosis). Tuberculosis (abbreviated as TB for tubercle bacillus or T u' b' erculosis Bacillus --> is a common It can be considered a combination of coagulative and liquefactive necroses.
• Fatty necrosis results from the action of lipases on fatty tissues (e. Fats consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water A lipase is a Water-soluble Enzyme that Catalyzes the Hydrolysis of Ester bonds in water–insoluble Lipid g. acute pancreatitis, breast tissue necrosis). Acute Pancreatitis is a sudden Inflammation of the Pancreas. Depending on its severity it can have severe complications and high mortality despite The breast is the upper Ventral region of an animal’s Torso, particularly that of Mammals including Human beings.
• Fibrinoid necrosis is caused by immune-mediated vascular damage. Fibrinoid necrosis is a special type of Necrosis that can be seen in blood vessel walls Immunity is a material term that describes a state of having sufficient biological defenses to avoid Infection, Disease, or other unwanted biological invasion The blood vessels are part of the Circulatory system and function to transport Blood throughout the body It is marked by deposition of fibrin-like proteinaceous material in arterial walls, which appears smudgy and eosinophilic on light microscopy. Fibrin (also called Factor Ia) is a Protein involved in the clotting of blood Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Arteries are Blood vessels that carry blood away from the Heart. See also Eosin Eosinophilic means loves eosin, and refers to the Staining of certain tissues, cells, or Organelles

Arachnogenic necrosis

Spider bites are cited as causing necrosis in some areas. '''Spiders''' occasionally bite humans Although 98-99% of spider bites are harmless more rarely the symptoms of their bites can include necrotic wounds systemic These claims are widely disputed. In the US at least, only the bites of spiders in the genus Loxosceles or brown recluse have been proven to consistently cause necrosis. The recluse spiders (genus Loxosceles) also known as fiddle-back or violin spiders, are a venomous genus of spiders known for ^[2] Many other spider species are claimed to cause necrosis but in most cases firm evidence is lacking. Partially this is because the early bite is often painless and the spider species cannot be identified.

Several species of spiders possess toxins proven to cause necrosis:

• Loxosceles spiders, including the brown recluse in the midwestern United States and the Chilean recluse in South America

Spiders suspected of, but not shown to cause necrosis:

• White-tailed spiders in Australia and New Zealand^[3]
• Hobo spider in northwestern USA^[4]
• Sac spider in United States and Australia^[5]

See also

• Peripheral vascular disease
• Osteonecrosis of the jaw
• Aseptic bone necrosis
• Gangrene
• Ischemic cascade
• Necrotoxins are toxins that cause necrosis
• Apoptosis

Footnotes