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Botulin
Botulinum toxin, or botulinum neurotoxin (commonly called botox), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction, thus causing flaccid paralysis. The toxin causes the disease botulism. The toxin is also used commercially for medical and cosmetic purposes. Botulinum toxin is an acetylcholine release inhibitor and a neuromuscular blocking agent. The seven main types of botulinum toxin are named types A to G (A, B, C1, C2, D, E, F and G). New types are occasionally found. Types A and B are capable of causing disease in humans, and are also used commercially and medically. Types C–G are less common; types E and F can cause disease in humans, while the other types cause disease in other animals. Botulinum toxins are among the most potent toxins known to science. Intoxication can occur naturally as a result of either w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clostridium Botulinum
''Clostridium botulinum'' is a Gram-positive bacteria, gram-positive, Bacillus (shape), rod-shaped, Anaerobic organism, anaerobic, endospore, spore-forming, Motility, motile bacterium with the ability to produce botulinum toxin, which is a neurotoxin. ''C. botulinum'' is a diverse group of pathogenic bacteria. Initially, they were grouped together by their ability to produce botulinum toxin and are now known as four distinct groups, ''C. botulinum'' groups I–IV. Along with some strains of ''Clostridium butyricum'' and ''Clostridium baratii'', these bacteria all produce the toxin. Botulinum toxin can cause botulism, a severe Flaccid paralysis, flaccid paralytic disease in humans and other animals, and is the most potent toxin known to science, natural or synthetic, with a lethal dose of 1.3–2.1 ng/kg in humans.(2010). Chapter 19. ''Clostridium'', ''Peptostreptococcus'', ''Bacteroides'', and Other Anaerobes. In Ryan K.J., Ray C (Eds), ''Sherris Medical Microbiology'', 5th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botulism
Botulism is a rare and potentially fatal illness caused by botulinum toxin, which is produced by the bacterium ''Clostridium botulinum''. The disease begins with weakness, blurred vision, Fatigue (medical), feeling tired, and trouble speaking. This may then be followed by weakness of the arms, chest muscles, and legs. Vomiting, swelling of the abdomen, and diarrhea may also occur. The disease does not usually affect consciousness or cause a fever. Botulism can occur in several ways. The bacterial spores which cause it are common in both soil and water and are very resistant. They produce the botulinum toxin when exposed to low oxygen levels and certain temperatures. Foodborne botulism happens when food containing the toxin is eaten. Infant botulism instead happens when the bacterium develops in the intestines and releases the toxin. This typically only occurs in children less than one year old, as protective mechanisms against development of the bacterium develop after that age ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blepharospasm
Blepharospasm is a neurological disorder characterized by intermittent, involuntary spasms and contractions of the orbicularis oculi muscle, orbicularis oculi (eyelid) muscles around both eyes. These result in abnormal twitching or blinking, and in the extreme, sustained eyelid closure resulting in functional blindness. The word blepharospasm is derived from the Greek: βλέφαρον / blepharon, eyelid, and σπασμός / spasmos, ''spasm,'' an uncontrolled muscle contraction. The condition should be distinguished from the more common, and milder, involuntary quivering of an eyelid, known as myokymia or fasciculation. Blepharospasm is one form of a group of movement disorders called dystonia. It may be a primary or secondary disorder. The primary disorder is benign essential blepharospasm, in which term the qualifier ''essential'' indicates that the Idiopathic, cause is unknown. Blepharospasm may occur as secondary to conditions including dry eyes and other specific ocul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Median Lethal Dose
In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a given substance. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of higher toxicity. The term LD50 is generally attributed to John William Trevan. The test was created by J. W. Trevan in 1927. The term semilethal dose is occasionally used in the same sense, in particular with translations of foreign language text, but can also refer to a sublethal dose. LD50 is usually determined by tests on animals such as laboratory mice. In 2011, the U.S. Food and Drug Administration approved alternative methods to LD50 for testing the cosmetic drug botox without animal tests. Conventions The LD50 is usually expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromuscular Junction
A neuromuscular junction (or myoneural junction) is a chemical synapse between a motor neuron and a muscle fiber. It allows the motor neuron to transmit a signal to the muscle fiber, causing muscle contraction. Muscles require innervation to function—and even just to maintain muscle tone, avoiding atrophy. In the neuromuscular system, nerves from the central nervous system and the peripheral nervous system are linked and work together with muscles. Synaptic transmission at the neuromuscular junction begins when an action potential reaches the presynaptic terminal of a motor neuron, which activates voltage-gated calcium channels to allow calcium ions to enter the neuron. Calcium ions bind to sensor proteins (synaptotagmins) on synaptic vesicles, triggering vesicle fusion with the cell membrane and subsequent neurotransmitter release from the motor neuron into the synaptic cleft. In vertebrates, motor neurons release acetylcholine (ACh), a small molecule neurotransmitter, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Palsy
Cerebral palsy (CP) is a group of movement disorders that appear in early childhood. Signs and symptoms vary among people and over time, but include poor coordination, spasticity, stiff muscles, Paresis, weak muscles, and tremors. There may be problems with sense, sensation, visual perception, vision, hearing, and speech. Often, babies with cerebral palsy do not roll over, sit, crawl or walk as early as other children. Other symptoms may include seizures and problems with cognition, thinking or reasoning. While symptoms may get more noticeable over the first years of life, underlying problems do not worsen over time. Cerebral palsy is caused by abnormal development or damage to the parts of the brain that control movement, balance, and posture. Most often, the problems occur during pregnancy, but may occur during childbirth or shortly afterwards. Often, the cause is unknown. Risk factors include preterm birth, being a twin, certain infections or exposure to methylmercury duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxin
Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achalasia
Esophageal achalasia, often referred to simply as achalasia, is a failure of smooth muscle fibers to relax, which can cause the lower esophageal sphincter to remain closed. Without a modifier, "achalasia" usually refers to achalasia of the esophagus. Achalasia can happen at various points along the human gastrointestinal tract, gastrointestinal tract; achalasia of the rectum, for instance, may occur in Hirschsprung's disease. The lower esophageal sphincter is a muscle between the esophagus and stomach that opens when food comes in. It closes to avoid Gastric acid, stomach acids from coming back up. A fully understood cause to the disease is unknown, as are factors that increase the risk of its appearance. Suggestions of a Genetic disorder, genetically transmittable form of achalasia exist, but this is neither fully understood, nor agreed upon. Esophageal achalasia is an esophageal motility disorder involving the smooth muscle cell, smooth muscle layer of the esophagus and the lowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Fissure
An anal fissure is a break or tear in the skin of the anal canal. Anal fissures may be noticed by bright red anal bleeding on toilet paper and undergarments, or sometimes in the toilet. If acute they are painful after defecation, but with chronic fissures, pain intensity often reduces and becomes cyclical. Causes Most anal fissures are caused by stretching of the anal mucous membrane beyond its capability. Superficial or shallow anal fissures look much like a paper cut, and may be hard to detect upon visual inspection; they will generally self-heal within a couple of weeks. However, some anal fissures become chronic and deep and will not heal. The most common cause of non-healing is spasming of the internal anal sphincter muscle which results in impaired blood supply to the anal mucosa. The result is a non-healing ulcer, which may become infected by fecal bacteria. In adults, fissures may be caused by constipation, the passing of large, hard stools, or by prolonged diar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flaccid Paralysis
Flaccid paralysis is a neurological condition characterized by weakness or paralysis and reduced muscle tone without other obvious cause (e.g., trauma). This abnormal condition may be caused by disease or by trauma affecting the nerves associated with the involved muscles. For example, if the somatic nerves to a skeletal muscle are severed, then the muscle will exhibit flaccid paralysis. When muscles enter this state, they become limp and cannot contract. This condition can become fatal if it affects the respiratory muscles, posing the threat of suffocation. It also occurs in the spinal shock stage in complete transection of the spinal cord occurring in injuries such as gunshot wounds.Saladin, Kenneth S. Anatomy & Physiology: The Unity of Form and Function. McGraw-Hill. 6th Edition. 2012. Causes Polio and other viruses The term ''acute flaccid paralysis'' (AFP) is often used to describe an instance with a sudden onset, as might be found with polio. AFP is the most co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dystonia
Dystonia is a neurology, neurological Hyperkinesia, hyperkinetic Movement disorders, movement disorder in which sustained or repetitive muscle contractions occur involuntarily, resulting in twisting and repetitive movements or abnormal fixed postures. The movements may resemble a tremor. Dystonia is often intensified or exacerbated by physical activity, and symptoms may progress into adjacent muscles. The disorder may be Heredity, hereditary or caused by other factors such as birth trauma (physical), birth-related or other Injury, physical trauma, infection, poisoning (e.g., lead poisoning) or reaction to Medication, pharmaceutical drugs, particularly Antipsychotic, neuroleptics, or stress. Treatment must be highly customized to the needs of the individual and may include oral medications, chemodenervation Botulinum toxin, botulinum neurotoxin injections, physical therapy, or other supportive therapies, and surgical procedures such as deep brain stimulation. Classification The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruxism
Bruxism is excessive teeth grinding or jaw clenching. It is an oral Parafunctional habit, parafunctional activity; i.e., it is unrelated to normal function such as eating or talking. Bruxism is a common behavior; the global prevalence of bruxism (both sleep and awake) is 22.22%. Several symptoms are commonly associated with bruxism, including aching jaw muscles, headaches, hypersensitive teeth, tooth wear, and damage to dental restorations (e.g. crowns and fillings). Symptoms may be minimal, without patient awareness of the condition. If nothing is done, after a while many teeth start wearing down until the whole tooth is gone. There are two main types of bruxism: one occurs during sleep (nocturnal bruxism) and one during wakefulness (awake bruxism). Dental damage may be similar in both types, but the symptoms of sleep bruxism tend to be worse on waking and improve during the course of the day, and the symptoms of awake bruxism may not be present at all on waking, and then wo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
