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DASB
DASB, also known as 3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile, is a compound that binds to the serotonin transporter. Labeled with carbon-11 — a radioactive isotope — it has been used as a radioligand in neuroimaging with positron emission tomography (PET) since around year 2000. In this context it is regarded as one of the superior radioligands for PET study of the serotonin transporter in the brain, since it has high selectivity for the serotonin transporter. The DASB image from a human PET scan shows high binding in the midbrain, thalamus and striatum, moderate binding in the medial temporal lobe and anterior cingulate, and low binding in neocortex. The cerebellum is often regarded as a region with no specific serotonin transporter binding and the brain region is used as a reference in some studies. Since the serotonin transporter is the target of SSRIs used in the treatment of major depression it has been natural to examine DASB binding in de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin Transporter
The serotonin transporter (SERT or 5-HTT) also known as the sodium-dependent serotonin transporter and solute carrier family 6 member 4 is a protein that in humans is encoded by the SLC6A4 gene. SERT is a type of monoamine transporter protein that transports the neurotransmitter serotonin from the synaptic cleft back to the presynaptic neuron, in a process known as serotonin reuptake. This transport of serotonin by the SERT protein terminates the action of serotonin and recycles it in a sodium-dependent manner. Many antidepressant medications of the SSRI and tricyclic antidepressant classes work by binding to SERT and thus reducing serotonin reuptake. It is a member of the sodium:neurotransmitter symporter family. A repeat length polymorphism in the promoter of this gene has been shown to affect the rate of serotonin uptake and may play a role in sudden infant death syndrome, aggressive behavior in Alzheimer disease patients, post-traumatic stress disorder and depression ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HTTLPR
5-HTTLPR (serotonin-transporter-linked promoter region) is a degenerate repeat (redundancy in the genetic code) polymorphic region in '' SLC6A4'', the gene that codes for the serotonin transporter. Since the polymorphism was identified in the middle of the 1990s, it has been extensively investigated, e.g., in connection with neuropsychiatric disorders. A 2006 scientific article stated that "over 300 behavioral, psychiatric, pharmacogenetic and other medical genetics papers" had analyzed the polymorphism. While often discussed as an example of gene-environment interaction, this contention is contested. Alleles 150px, The serotonin transporter gene (''SLC6A4'') with the 5-HTTLPR is located on chromosome 17. The polymorphism occurs in the promoter region of the gene. Researchers commonly report it with two variations in humans: A ''short ("s")'' and a ''long ("l")'', but it can be subdivided further. The short (s)- and long (l)- alleles have been thought to be related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-11
Carbon (6C) has 14 known isotopes, from to as well as , of which only and are stable nuclide, stable. The longest-lived radionuclide, radioisotope is , with a half-life of years. This is also the only carbon radioisotope found in nature, as trace quantities are formed cosmogenic nuclide, cosmogenically by the reaction + → + . The most stable artificial radioisotope is , which has a half-life of . All other radioisotopes have half-lives under 20 seconds, most less than 200 milliseconds. The least stable isotope is , with a half-life of . Light isotopes tend to decay into isotopes of boron and heavy ones tend to decay into isotopes of nitrogen. List of isotopes , -id=Carbon-8 , , style="text-align:right" , 6 , style="text-align:right" , 2 , , [] , proton emission, 2p , Also immediately emits two protons for the net reaction of → + 4 , 0+ , , , -id=Carbon-9 , rowspan=3, , rowspan=3 style="text-align:right" , 6 , rowspan=3 style="text-align ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McN5652
McN5652 is a molecule that can be radiolabeled and then used as a radioligand in positron emission tomography (PET) studies. The [11C]-(+)-McN5652 enantiomer binds to the serotonin transporter. The radioligand is used for molecular neuroimaging and for imaging of the lungs. It was developed by Johnson & Johnson's McNeil Laboratories. According to McNeil, McN5652 was among the strongest SRI ever reported at the time of its discovery (sub nM Ki). However, it is not completely 5-HT selective: the racemate has 5-HT=0.68, NA=2.9, and D=36.8nM, whereas (+)-enantiomer has 5-HT=0.39, NA=1.8, and D=23.5 nM. Paroxetine was listed as 5-HT=0.44 nM, NA=20, and DA=460nM in the same paper by the same authors. Derivatives McN5652 and related structures have been analyzed for QSAR in terms of binding to the MAT receptor binding site. See also * DASB DASB, also known as 3-amino-4-(2-dimethylaminomethylphenylsulfanyl)-benzonitrile, is a compound that binds to the serotonin transport ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positron Emission Tomography
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, regional chemical composition, and absorption. Different tracers are used for various imaging purposes, depending on the target process within the body, such as: * Fluorodeoxyglucose ( 18F">sup>18FDG or FDG) is commonly used to detect cancer; * 18Fodium fluoride">sup>18Fodium fluoride (Na18F) is widely used for detecting bone formation; * Oxygen-15 (15O) is sometimes used to measure blood flow. PET is a common imaging technique, a medical scintillography technique used in nuclear medicine. A radiopharmaceutical—a radioisotope attached to a drug—is injected into the body as a tracer. When the radiopharmaceutical undergoes beta plus decay, a positron is emitted, and when the positron interacts with an ordinary electron, the tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WAY-100635
WAY-100635 is a piperazine drug and research chemical widely used in scientific studies. It was originally believed to act as a selective 5-HT1A receptor antagonist, but subsequent research showed that it also acts as potent full agonist at the D4 receptor. It is sometimes referred to as a silent antagonist at the former receptor. It is closely related to WAY-100135. In light of its dopaminergic activity, conclusions drawn from studies that employ WAY-100635 as a selective 5-HT1A antagonist may need to be re-evaluated. Human PET studies In human PET studies WAY-100635 shows high binding in the cerebral cortex, hippocampus, raphe nucleus and amygdaloid nucleus, while lower in thalamus and basal ganglia. One study described a single case with relatively high binding in the cerebellum. In relating its binding to subject variables one Swedish study found WAY-100635 binding in raphe brain region correlating with self-transcendence and spiritual acceptance personality traits. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Altanserin
Altanserin is a compound that binds to the 5-HT2A receptor (5-Hydroxytryptamine (serotonin) 2A receptor). Labeled with the isotope fluorine-18 it is used as a radioligand in positron emission tomography (PET) studies of the brain, i.e., studies of the 5-HT2A neuroreceptors. Besides human neuroimaging studies altanserin has also been used in the study of rats. An alternative for PET imaging the 5-HT2A receptor is the [ 11C] volinanserin (MDL-100,907) radioligand. 18F-altanserin and 3H-volinanserin have shown very comparable binding. Both altanserin and MDL 100,907 are 5-HT2A receptor antagonists. 18F">sup>18F setoperone can also be used in PET. An alternative SPECT radioligand is the 123I">sup>123I 5-I-R91150 receptor antagonist. A rapid chemical synthesis of fluorine-18 and H-2 dual-labeled altanserin has been described. Other ligands for other parts of the serotonin system used in PET studies are, e.g., DASB, ketanserin, and WAY-100635. Human brain mapping stu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioligand
A radioligand is a microscopic particle which consists of a Radiopharmaceutical, therapeutic radioactive isotope and the cell-targeting compound - the ligand. The ligand is the target binding site, it may be on the surface of the targeted cancer cell for therapeutic purposes. Radioisotopes can occur naturally or be synthesized and produced in a cyclotron/nuclear reactor. The different types of radioisotopes include Y-90, H-3, C-11, Lu-177, Ac-225, Ra-223, In-111, I-131, I-125, etc. Thus, radioligands must be produced in special nuclear reactors for the radioisotope to remain stable. Radioligands can be used to analyze/characterize receptors, to perform binding assays, to help in diagnostic imaging, and to provide targeted cancer therapy. Radiation is a novel method of treating cancer and is effective in short distances along with being unique/personalizable and causing minimal harm to normal surrounding cells. Furthermore, radioligand binding can provide information about receptor-l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproducibility
Reproducibility, closely related to replicability and repeatability, is a major principle underpinning the scientific method. For the findings of a study to be reproducible means that results obtained by an experiment or an observational study or in a statistical analysis of a data set should be achieved again with a high degree of reliability when the study is replicated. There are different kinds of replication but typically replication studies involve different researchers using the same methodology. Only after one or several such successful replications should a result be recognized as scientific knowledge. History The first to stress the importance of reproducibility in science was the Anglo-Irish chemist Robert Boyle, in England in the 17th century. Boyle's air pump was designed to generate and study vacuum, which at the time was a very controversial concept. Indeed, distinguished philosophers such as René Descartes and Thomas Hobbes denied the very possibility of vacuum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test-retest Reliability
Repeatability or test–retest reliability is the closeness of the agreement between the results of successive measurements of the same measure, when carried out under the same conditions of measurement. In other words, the measurements are taken by a single person or instrument on the same item, under the same conditions, and in a short period of time. A less-than-perfect test–retest reliability causes test–retest variability. Such variability can be caused by, for example, intra-individual variability and inter-observer variability. A measurement may be said to be ''repeatable'' when this variation is smaller than a predetermined acceptance criterion. Test–retest variability is practically used, for example, in medical monitoring of conditions. In these situations, there is often a predetermined "critical difference", and for differences in monitored values that are smaller than this critical difference, the possibility of variability as a sole cause of the difference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinetic Modeling
Kinetic (Ancient Greek: κίνησις “kinesis”, movement or to move) may refer to: * Kinetic theory, describing a gas as particles in random motion * Kinetic energy, the energy of an object that it possesses due to its motion Art and entertainment * Kinetic art, a form of art involving mechanical and/or random movement, including optical illusions. * ''Kinetic'', the 13th episode of the first season of the TV series ''Smallville'' * ''Kinetic'' (comics), a comic by Allan Heinberg and Kelley Pucklett * "Kinetic" (song), a song by Radiohead Business * Kinetic, a brand of Windstream Holdings * Kinetic Engineering Limited, Indian automotive manufacturer * Kinetic Group, Australian-based public transport company Technology * "Kinetic", Seiko's trademark for its automatic quartz technology * The ''Kinetic camera system'' by Birt Acres (1854–1918), photographer and film pioneer * Kinetic projectile Military terminology * Kinetic military action See also * * * Kinetics ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binding Potential
In pharmacokinetics and receptor-ligand kinetics the binding potential (BP) is a combined measure of the density of "available" neuroreceptors and the Affinity (pharmacology), affinity of a drug to that neuroreceptor. Description Consider a ligand receptor binding system. Ligand with a concentration ''L'' associates with a receptor of concentration or availability ''R'' to form a ligand-receptor complex with concentration ''RL''. The binding potential is then the ratio ligand-receptor complex to free ligand at equilibrium and in the limit of L tending to 0, and is given symbol BP: BP=\frac\bigg, _ This quantity, originally defined by Mintun, describes the capacity of a receptor to bind ligand. It is a limit (L << Ki) of the general receptor association equation: and is thus also equivalent to: These equations apply equally when measuring the total receptor density or the residual receptor density available after binding to second li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
