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Oenanthotoxin
Oenanthotoxin is a toxin extracted from hemlock water-dropwort (''Oenanthe crocata'') and other plants of the genus '' Oenanthe''. It is a central nervous system poison, and acts as a noncompetitive antagonist of the neurotransmitter gamma-aminobutyric acid. A case has been made for the presence of this toxin in local '' Oenanthe'' species playing a causative role in euthanasia in ancient Sardinia. It was crystallized in 1949 by Clarke and co-workers. It is structurally closely related to the toxins cicutoxin and carotatoxin. Oenanthotoxin is a C17 polyacetylene isomer of cicutoxin. Occurrence Oenanthotoxin concentration in plants is dependent on seasonal changes and geographical location, the most is present during late winter and early spring. Contrary to most poisonous plants that contain bitter tastes or burning sensations, the water dropwort has a rather sweet and pleasant taste and odor. Water dropwort is characterized by a yellow liquid that changes color due to air ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cicutoxin
Cicutoxin is a naturally-occurring poisonous chemical compound produced by several plants from the family Apiaceae including water hemlock (''Cicuta'' species) and water dropwort (''Oenanthe crocata''). The compound contains polyene, polyyne, and alcohol functional groups and is a structural isomer of oenanthotoxin, also found in water dropwort. Both of these belong to the C17-polyacetylenes chemical class. It causes death by respiratory paralysis resulting from disruption of the central nervous system. It is a potent, noncompetitive antagonist of the gamma-aminobutyric acid (GABA) receptor. In humans, cicutoxin rapidly produces symptoms of nausea, emesis and abdominal pain, typically within 60 minutes of ingestion. This can lead to tremors, seizures, and death. LD50(mouse; i.p.) ~9 mg/kg History Johann Jakob Wepfer's book ''Cicutae Aquaticae Historia Et Noxae Commentario Illustrata'' was published in 1679; it contains the earliest published report of toxicity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyyne
In organic chemistry, a polyyne () is any organic compound with alternating single and triple bonds; that is, a series of consecutive alkynes, with ''n'' greater than 1. These compounds are also called polyacetylenes, especially in the natural products and chemical ecology literature, even though this nomenclature more properly refers to acetylene polymers composed of alternating single and double bonds with ''n'' greater than 1. They are also sometimes referred to as oligoynes, or carbinoids after "carbyne" , the hypothetical allotrope of carbon that would be the ultimate member of the series. In ''Avancés récentes en chimie des acétylènes – Recent advances in acetylene chemistry'' The synthesis of this substance has been claimed several times since the 1960s, but those reports have been disputed. Indeed, the substances identified as short chains of "carbyne" in many early organic synthesis attempts would be called polyynes today. The simplest polyyne is diacetylene o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oenanthe (plant)
''Oenanthe'', known as water dropworts, oenanthes, water parsleys, and water celeries, are a genus of plants in the family Apiaceae. Most of the species grow in damp ground, such as in marshes or in water. Several of the species are extremely poisonous, the active poison being oenanthotoxin. The most notable of these is ''O. crocata'', which lives in damp, marshy ground, and resembles celery with roots like a bunch of large white carrots. The leaves may be eaten safely by livestock, but the stems, and especially the carbohydrate-rich roots are much more poisonous. Animals familiar with eating the leaves may eat the roots when these are exposed during ditch clearance: one root is sufficient to kill a cow, and human fatalities are also known. It has been referred to as the most poisonous of all British plants, and is considered particularly dangerous because of its similarity to several edible plants. The species '' O. javanica'', commonly known as Chinese celery or Japanese pars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oenanthe Crocata
''Oenanthe crocata'', hemlock water-dropwort (sometimes known as dead man's fingers) is a flowering plant in the carrot family, native to Europe, North Africa and western Asia. It grows in damp grassland and wet woodland, often along river and stream banks. All parts of the plant are extremely toxic and it has been known to cause human and livestock poisoning. Description Hemlock water-dropwort is a robust hairless perennial growing up to 150 cm tall with hollow, cylindrical, grooved stems up to 3.5 cm across. The stems are often branched. The upper part of the roots include five or more obovoid, pale yellow, fleshy tubers up to 6 cm long, which exude a yellowish oily fluid when cut that stains the skin. The lower leaves are 3–4 times pinnate, triangular, with oval toothed leaflets 10–20 mm long, that are basally tapered to the stalk ( cuneate). The upper leaves are 1–2 pinnate, with narrower lobes and a shorter petiole (leaf stalk). All the leaves ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAA Receptor
The GABAA receptor (GABAAR) is an ionotropic receptor and ligand-gated ion channel. Its endogenous ligand is γ-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Upon opening, the GABAA receptor on the postsynaptic cell is selectively permeable to chloride ions (Cl−) and, to a lesser extent, bicarbonate ions (HCO3−). Depending on the membrane potential and the ionic concentration difference, this can result in ionic fluxes across the pore. If the membrane potential is higher than the equilibrium potential (also known as the reversal potential) for chloride ions, when the receptor is activated Cl− will flow into the cell. This causes an inhibitory effect on neurotransmission by diminishing the chance of a successful action potential occurring at the postsynaptic cell. The reversal potential of the GABAA-mediated inhibitory postsynaptic potential (IPSP) in normal solution is −70 mV, contrasting the GABAB IPSP (-100 mV). T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carotatoxin
Falcarinol (also known as carotatoxin or panaxynol) is a natural pesticide and fatty alcohol found in carrots (''Daucus carota''), red ginseng (''Panax ginseng'') and ivy. In carrots, it occurs in a concentration of approximately 2 mg/kg. As a toxin, it protects roots from fungal diseases, such as liquorice rot that causes black spots on the roots during storage. The compound requires the freezing condition to maintain well because it is sensitive to light and heat. Falcarinol was also credited for helping to prevent colon cancer. Chemistry Falcarinol is a polyyne with two carbon-carbon triple bonds and two double bonds. The double bond at the carbon 9 position has ''cis'' stereochemistry was introduced by the desaturation, which requires oxygen and NADPH (or NADH) cofactors, creates a bend in the molecule that prevent fatty acid from solidifying in oils and cellular membranes. It is structurally related to the oenanthotoxin and cicutoxin. Biological effects Falcarinol is ... [...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] |
Brachycardia
Bradycardia (also sinus bradycardia) is a slow resting heart rate, commonly under 60 beats per minute (BPM) as determined by an electrocardiogram. It is considered to be a normal heart rate during sleep, in young and healthy or elderly adults, and in athletes. In some people, bradycardia below 60 BPM may be associated with fatigue, weakness, dizziness, sweating, and fainting. The term "relative bradycardia" is used to refer to a heart rate slower than an individual's typical resting heart rate. Athletes may have athletic heart syndrome, which includes bradycardia as part of the cardiovascular adaptations to training and participation. The word "bradycardia" is from the Greek βραδύς ''bradys'' "slow", and καρδία ''kardia'' "heart". Classification Sinus Atrial bradycardias are divided into three types. The first, respiratory sinus arrhythmia, is usually found in young and healthy adults. Heart rate increases during inhalation and decreases during exhalation. This i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Opisthotonus
Opisthotonus or opisthotonos (from grc, ὄπισθεν, translit=opisthen, lit=behind and grc, τόνος, translit=tonos, lit=tension, label=none) is a state of severe hyperextension and spasticity in which an individual's head, neck and spinal column enter into a complete "bridging" or "arching" position. This extreme arched pose is an extrapyramidal effect and is caused by spasm of the axial muscles along the spinal column. It has been shown to occur naturally in birds, snakes suffering from advanced boid inclusion body disease, and placental mammals, among existing animals; it is observed in some articulated dinosaur fossils. Causes Opisthotonus is a symptom of some cases of severe cerebral palsy and traumatic brain injury or as a result of the severe muscular spasms associated with tetanus. It can be a feature of severe acute hydrocephalus, poisoning, and drowning. Infants Opisthotonus is more pronounced in infants. Opisthotonus in the neonate may be a symptom of mening ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Status Epilepticus
Status epilepticus (SE), or status seizure, is a single seizure lasting more than 5 minutes or 2 or more seizures within a 5-minute period without the person returning to normal between them. Previous definitions used a 30-minute time limit. The seizures can be of the tonic–clonic type, with a regular pattern of contraction and extension of the arms and legs, or of types that do not involve contractions, such as absence seizures or complex partial seizures. Status epilepticus is a life-threatening medical emergency, particularly if treatment is delayed. Status epilepticus may occur in those with a history of epilepsy as well as those with an underlying problem of the brain. These underlying brain problems may include trauma, infections, or strokes, among others. Diagnosis often involves checking the blood sugar, imaging of the head, a number of blood tests, and an electroencephalogram. Psychogenic nonepileptic seizures may present similarly to status epilepticus. Other conditio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteinuria
Proteinuria is the presence of excess proteins in the urine. In healthy persons, urine contains very little protein; an excess is suggestive of illness. Excess protein in the urine often causes the urine to become foamy (although this symptom may also be caused by other conditions). Severe proteinuria can cause nephrotic syndrome in which there is worsening swelling of the body. Signs and symptoms Proteinuria often causes no symptoms and it may only be discovered incidentally. Foamy urine is considered a cardinal sign of proteinuria, but only a third of people with foamy urine have proteinuria as the underlying cause. It may also be caused by bilirubin in the urine ( bilirubinuria), retrograde ejaculation, pneumaturia (air bubbles in the urine) due to a fistula, or drugs such as pyridium. Causes There are three main mechanisms to cause proteinuria: * Due to disease in the glomerulus * Because of increased quantity of proteins in serum (overflow proteinuria) * Due to low r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycosuria
Glycosuria is the excretion of glucose into the urine. Ordinarily, urine contains no glucose because the kidneys are able to reabsorb all of the filtered glucose from the tubular fluid back into the bloodstream. Glycosuria is nearly always caused by elevated blood glucose levels, most commonly due to untreated diabetes mellitus. Rarely, glycosuria is due to an intrinsic problem with glucose reabsorption within the kidneys (such as Fanconi syndrome), producing a condition termed ''renal glycosuria''. Glycosuria leads to excessive water loss into the urine with resultant dehydration, a process called osmotic diuresis. Alimentary glycosuria is a temporary condition, when a high amount of carbohydrate is taken, it is rapidly absorbed in some cases where a part of the stomach is surgically removed, the excessive glucose appears in urine producing glycosuria. Follow-up In a patient with glucosuria, diabetes is confirmed by measuring fasting or random plasma glucose and glycated hemog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
