Instruct: Given a question, retrieve relevant passages that answer the question.
Query: Who discovered 5-Hydroxyeicosatetraenoic acid?
The Nobel laureate, Bengt I. Samuelsson, and colleagues first described 5("S")-HETE in 1976 as a metabolite of arachidonic acid made by rabbit neutrophils. Biological activity was linked to it several years later when it was found to stimulate human neutrophil rises in cytosolic calcium, chemotaxis, and increases in their cell surface adhesiveness as indicated by their aggregation to each other. Since a previously discovered arachidonic acid metabolite made by neutrophils, leukotriene B4 (LTB), also stimulates human neutrophil calcium rises, chemotaxis, and auto-aggregation and is structurally similar to 5("S")-HETE in being a 5-("S")-hydroxy-eicosateraenoate, it was assumed that 5-("S")-HETE stimulated cells through the same cell surface receptors as those used by (LTB) viz., the leukotriene B4 receptors. However, further studies in neutrophils indicated that 5-("S")-HETE acts through a receptor distinct from that used by LTB as well as various other neutrophil stimuli. This 5("S")-HETE receptor is termed the oxoeicosanoid receptor 1 (abbreviated as (OXER1).
Mitochondrial DNA was discovered in the 1960s by Margit M. K. Nass and Sylvan Nass by electron microscopy as DNase-sensitive threads inside mitochondria, and by Ellen Haslbrunner, Hans Tuppy and Gottfried Schatz by biochemical assays on highly purified mitochondrial fractions.
In the early 1950s, Alexander Todd’s group pioneered H-phosphonate and phosphate triester methods of oligonucleotide synthesis. The reaction of compounds 1 and 2 to form H-phosphonate diester 3 is an H-phosphonate coupling in solution while that of compounds 4 and 5 to give 6 is a phosphotriester coupling (see phosphotriester synthesis below).
In 1958, Beecham scientists in the UK discovered the penicillin nucleus, 6-APA. From that starting material, a large number of new semisynthetic penicillins could be designed, whose activity was directed against problem infections.
The 2008 Nobel Prize in Physiology or Medicine was awarded to Montagnier and Françoise Barré-Sinoussi for the discovery of HIV. They shared the Prize with Harald zur Hausen, who discovered that human papilloma viruses can cause cervical cancer. Montagnier said he was "surprised" that Robert Gallo was not also recognized by the Nobel Committee: "It was important to prove that HIV was the cause of AIDS, and Gallo had a very important role in that. I'm very sorry for Robert Gallo." According to Maria Masucci, a member of the Nobel Assembly, "there was no doubt as to who made the fundamental discoveries."
The field of oxidative phosphorylation began with the report in 1906 by Arthur Harden of a vital role for phosphate in cellular fermentation, but initially only sugar phosphates were known to be involved. However, in the early 1940s, the link between the oxidation of sugars and the generation of ATP was firmly established by Herman Kalckar, confirming the central role of ATP in energy transfer that had been proposed by Fritz Albert Lipmann in 1941. Later, in 1949, Morris Friedkin and Albert L. Lehninger proved that the coenzyme NADH linked metabolic pathways such as the citric acid cycle and the synthesis of ATP. The term "oxidative phosphorylation" was coined by in 1939.
Secretin was the first hormone to be identified. In 1902, William Bayliss and Ernest Starling were studying how the nervous system controls the process of digestion. It was known that the pancreas secreted digestive juices in response to the passage of food (chyme) through the pyloric sphincter into the duodenum. They discovered (by cutting all the nerves to the pancreas in their experimental animals) that this process was not, in fact, governed by the nervous system. They determined that a substance secreted by the intestinal lining stimulates the pancreas after being transported via the bloodstream. They named this intestinal secretion "secretin". Secretin was the first such "chemical messenger" identified. This type of substance is now called a hormone, a term coined by Bayliss in 1905.
The Gastrin family is a group of peptides evolutionarily similar in structure and function. Commonly synthesized in antroduodenal G-cells. Regulate gastric function along with gastric acid secretion and mucosal growth.The Secretin family are peptides that act as local hormones which regulate regulate activity of G-protein coupled receptors. Most often found in the pancreas and the intestines. Secretin was discovered in 1902 by E. H. Starling. It was later linked to chemical regulation and was the first substance to be deemed a hormone.
3. Mark H. Whitnall, William G. Haynes, David J. Webb (1997). Principles of Medical Biology.
Fatty acids play an important role in normal brain development as well as maintaining proper neuronal function. It has been found that certain fatty acids that are in abundance in the brain may be linked with FFA1. These fatty acids likely activate FFA1, inducing an intracellular response. It has been found that docosahexaenoic acid (DHA) has a higher affinity than other fatty acids for FFA1. DHA makes up 30% and arachidonic acid, another fatty acid found in the brain, makes up 20% of the fatty acids in the brain. Both of these fatty acids must be obtained from the diet because the body cannot make them. A correct balance of these fatty acids is vital to normal brain function and structure. DHA is supplied to the brain via astrocytes, which release DHA so that it reaches a high enough concentration to act as an extracellular signal on FFA1.
The discovery of carbon nanotubes is largely attributed to Sumio Iijima of NEC in 1991, although carbon nanotubes have been produced and observed under a variety of conditions prior to 1991. Iijima's discovery of multi-walled carbon nanotubes in the insoluble material of arc-burned graphite rods in 1991 and Mintmire, Dunlap, and White's independent prediction that if single-walled carbon nanotubes could be made, then they would exhibit remarkable conducting properties helped create the initial buzz that is now associated with carbon nanotubes. Nanotube research accelerated greatly following the independent discoveries by Bethune at IBM and Iijima at NEC of "single-walled" carbon nanotubes and methods to specifically produce them by adding transition-metal catalysts to the carbon in an arc discharge.
The term "biochemistry" itself is derived from a combination of biology and chemistry. In 1877, Felix Hoppe-Seyler used the term ("biochemie" in German) as a synonym for physiological chemistry in the foreword to the first issue of "Zeitschrift für Physiologische Chemie" (Journal of Physiological Chemistry) where he argued for the setting up of institutes dedicated to this field of study. The German chemist Carl Neuberg however is often cited to have coined the word in 1903, while some credited it to Franz Hofmeister.
It was once generally believed that life and its materials had some essential property or substance (often referred to as the "vital principle") distinct from any found in non-living matter, and it was thought that only living beings could produce the molecules of life. Then, in 1828, Friedrich Wöhler published a paper on the synthesis of urea, proving that organic compounds can be created artificially. Since then, biochemistry has advanced, especially since the mid-20th century, with the development of new techniques such as chromatography, X-ray diffraction, dual polarisation interferometry, NMR spectroscopy, radioisotopic labeling, electron microscopy, and molecular dynamics simulations. These techniques allowed for the discovery and detailed analysis of many molecules and metabolic pathways of the cell, such as glycolysis and the Krebs cycle (citric acid cycle), and led to an understanding of biochemistry on a molecular level. Philip Randle is well-known for his discovery in diabetes research is possibly the glucose-fatty acid cycle in 1963.He confirmed that fatty acids reduce oxidation of sugar by the muscle. High fat oxidation was responsible for the insulin resistance.
The discovery of a role for the pancreas in diabetes is generally ascribed to Joseph von Mering and Oskar Minkowski, who in 1889 found that dogs whose pancreas was removed developed all the signs and symptoms of diabetes and died shortly afterwards. In 1910, Sir Edward Albert Sharpey-Schafer suggested that people with diabetes were deficient in a single chemical that was normally produced by the pancreas—he proposed calling this substance insulin, from the Latin "insula", meaning island, in reference to the insulin-producing islets of Langerhans in the pancreas. The endocrine role of the pancreas in metabolism, and indeed the existence of insulin, was further clarified in 1921, when Sir Frederick Grant Banting and Charles Herbert Best repeated the work of Von Mering and Minkowski, and went further to demonstrate they could reverse induced diabetes in dogs by giving them an extract from the pancreatic islets of Langerhans of healthy dogs. The islets of Langerhans was discovered in 1869 by an anatomist named Paul Langerhans. He identified the keys cells in the pancreas which produce the main substance that controls glucose levels in the body.
The true identity of the discoverers of carbon nanotubes is a subject of some controversy. A 2006 editorial written by Marc Monthioux and Vladimir Kuznetsov in the journal "Carbon" described the interesting and often-misstated origin of the carbon nanotube. A large percentage of academic and popular literature attributes the discovery of hollow, nanometer-size tubes composed of graphitic carbon to Sumio Iijima of NEC in 1991. He published a paper describing his discovery which initiated a flurry of excitement and could be credited by inspiring the many scientists now studying applications of carbon nanotubes. Though Iijima has been given much of the credit for discovering carbon nanotubes, it turns out that the timeline of carbon nanotubes goes back much further than 1991.
Dopamine was first synthesized in 1910 by George Barger and James Ewens at Wellcome Laboratories in London, England and first identified in the human brain by Kathleen Montagu in 1957. It was named dopamine because it is a monoamine whose precursor in the Barger-Ewens synthesis is 3,4-dihydroxyphenylalanine (levodopa or L-DOPA). Dopamine's function as a neurotransmitter was first recognized in 1958 by Arvid Carlsson and Nils-Åke Hillarp at the Laboratory for Chemical Pharmacology of the National Heart Institute of Sweden. Carlsson was awarded the 2000 Nobel Prize in Physiology or Medicine for showing that dopamine is not only a precursor of norepinephrine (noradrenaline) and epinephrine (adrenaline), but is also itself a neurotransmitter.
The HIV genome presented several additional mysteries. The virus genome contained regions that might specify as yet unknown proteins. The Haseltine laboratory discovered a novel transacting protein and a second protein, both required for virus replication. They named the transactivator tat and the second protein art; the latter was renamed rev. He predicted that drugs that target these proteins will also be effective in treating the infection. A drug that inhibits the "rev" protein has been approved by the USA Food and Drug administration for treatment of HIV infection. His laboratory went on to discover additional viral genes and proteins – "vpr", "vpu", "vif", and "nef" - required for efficient virus growth in some but not all circumstances. The discoveries were summarized in an article in 1988 in "Scientific American".
Various genetic discoveries have been essential in the development of genetic engineering. Genetic inheritance was first discovered by Gregor Mendel in 1865 following experiments crossing peas. Although largely ignored for 34 years he provided the first evidence of hereditary segregation and independent assortment. In 1889 Hugo de Vries came up with the name "(pan)gene" after postulating that particles are responsible for inheritance of characteristics and the term "genetics" was coined by William Bateson in 1905. In 1928 Frederick Griffith proved the existence of a "transforming principle" involved in inheritance, which Avery, MacLeod and McCarty later (1944) identified as DNA. Edward Lawrie Tatum and George Wells Beadle developed the central dogma that genes code for proteins in 1941. The double helix structure of DNA was identified by James Watson and Francis Crick in 1953.As well as discovering how DNA works, tools had to be developed that allowed it to be manipulated. In 1970 Hamilton Smith's lab discovered restriction enzymes that allowed DNA to be cut at specific places and separated out on an electrophoresis gel. This enabled scientists to isolate genes from an organism's genome. DNA ligases, that join broken DNA together, had been discovered earlier in 1967 and by combining the two enzymes it was possible to "cut and paste" DNA sequences to create recombinant DNA. Plasmids, discovered in 1952, became important tools for transferring information between cells and replicating DNA sequences. Frederick Sanger developed a method for sequencing DNA in 1977, greatly increasing the genetic information available to researchers. Polymerase chain reaction (PCR), developed by Kary Mullis in 1983, allowed small sections of DNA to be amplified and aided identification and isolation of genetic material.
Human growth hormone occurs naturally in the human body. Use of exogenous human growth hormone (HGH), via injection, was originally for medical purposes until athletes began abusing HGH with the goal of increasing their abilities. Before recombinant human growth hormone (rHGH) was developed in 1981, HGH was only available from cadavers. The arrival of rHGH combined with other peptide hormone advancements has increased the availability of HGH on both the legitimate and black markets. The first description of the use of GM as a doping agent was Dan Duchaine’s “Underground Steroid handbook” which emerged from California in 1982; it is not known where and when GM was first used this way. In 1989 the International Olympic Committee became the first to brand human growth hormone a banned substance. Although abuse of human growth hormone for athletic purposes is illegal in the U.S., over the past decade it appears that abuse of HGH is present in all levels of sport. This is fueled at least in part by the fact that HGH is more difficult to detect than most other performance-enhancing drugs, such as anabolic steroids. Athletes competing in power sports, bodybuilding, professional wrestling, mixed martial arts, swimming, baseball, strength sports, track and field, cycling, soccer, weight lifting, skiing and endurance sports have been said to abuse human growth hormone, including in combination with other performance-enhancing drugs such as androgenic anabolic steroids including testosterone, certain products which claim to enhance HGH, and erythropoietin (among others).
Another group working contemporaneously with the Montagnier and Gallo groups was that of Dr. Jay Levy at the University of California, San Francisco. He independently discovered the AIDS virus in 1983 and named it the AIDS associated retrovirus (ARV). This virus was very different from the virus reported by the Montagnier and Gallo groups. The ARV strains indicated, for the first time, the heterogeneity of HIV isolates and several of these remain classic examples of the AIDS virus found in the United States.
Iijima's discovery of multi-walled carbon nanotubes in the insoluble material of arc-burned graphite rods in 1991 and Mintmire, Dunlap, and White's independent prediction that if single-walled carbon nanotubes could be made, then they would exhibit remarkable conducting properties helped create the initial buzz that is now associated with carbon nanotubes. Nanotube research accelerated greatly following the independent discoveries by Bethune at IBM and Iijima at NEC of "single-walled" carbon nanotubes and methods to specifically produce them by adding transition-metal catalysts to the carbon in an arc discharge. The arc discharge technique was well-known to produce the famed Buckminster fullerene on a preparative scale, and these results appeared to extend the run of accidental discoveries relating to fullerenes. The discovery of nanotubes remains a contentious issue. Many believe that Iijima's report in 1991 is of particular importance because it brought carbon nanotubes into the awareness of the scientific community as a whole.
The physiological function of the AH receptor has been the subject of continuous research. One obvious function is to increase the activity of enzymes breaking down foreign chemicals or normal chemicals of the body as needed. There may be other functions, however, related to growth of various organs or other regulatory functions. The AH receptor is phylogenetically highly conserved transcription factor with a history of at least 500 million years, and found in all vertebrates, and its ancient analogs are important regulatory proteins even in more primitive species. In fact, knock-out animals with no AH receptor are prone to illness and developmental problems. Taken together, this implies the necessity of a basal degree of AH receptor activation to achieve normal physiological function.
Polyvinyl chloride (PVC) was discovered by French physicist Henri Victor Regnault, and German physicist Eugen Baumann. Klatte designed the production process, although never successfully commercialised it. Klatte is sometimes incorrectly attributed to be the discoverer or inventor of PVC.
5-Hydroxyeicosatetraenoic acid (5-HETE, 5("S")-HETE, or 5"S"-HETE) is an eicosanoid, i.e. a metabolite of arachidonic acid. It is produced by diverse cell types in humans and other animal species. These cells may then metabolize the formed 5("S")-HETE to 5-oxo-eicosatetraenoic acid (5-oxo-ETE), 5("S"),15("S")-dihydroxyeicosatetraenoic acid (5("S"),15("S")-diHETE), or 5-oxo-15-hydroxyeicosatetraenoic acid (5-oxo-15("S")-HETE).
CYP4F11 omega-hydroxylates leukotriene B4 (LTB4) to 20-hydroxy-LTB4, 5-Hydroxyicosatetraenoic acid (5-HETE) to 20-hydroxy-5-HETE (i.e. 5,20-diHETE), 12-hydroxyeicosatetraenoic acid (12-HETE) to 12,20-diHETE, lipoxins and possibly 5-oxo-eicosatetraenoic acid (5-oxo-ETE) to their 20-hydroxy metabolites; these reactions begin the inactivation of these pro- (LTB4, 5-HETE, 12-HETE, and 5-oxo-ETE) and anti- (lipoxins) cell signaling agents; however, it is relatively weak compared to, and therefore possibly not as physiologically relevant as, other CYP4Fs such as CYP4F2, CYP4F3a, CYP4F3b, CYP4A11 and CYP4F2 in doing so. The enzyme also hydroxylates arachidonic acid (i.e. eicosatetraenoic acid to 20-Hydroxyeicosatetraenoic acid) (20-HETE) although other cytochromes such as CYP4A11 and CYP4F2 appear more important in this metabolic conversion. 20-HETE is a short-lived potent signaling agent that functions to regulate blood flow, vascularization, blood pressure, and kidney tubule absorption of ions in rodents and possibly humans. Gene polymorphism variants of CYP4A11 are associated with the development of hypertension and cerebral infarction (i.e. ischemic stroke) in humans (see 20-Hydroxyeicosatetraenoic acid). In spite of its relative impotency and/or importance in accomplishing these omega-hydroxylations, CYP4F11 may contribute to them in certain tissues.
5(S)-HETE is a product of the cellular metabolism of the n-6 polyunsaturated fatty acid, arachidonic acid (i.e. 5"Z",8"Z",11"Z",14"Z"-eicosatetraenoic acid), by ALOX5 (also termed arachidonate-5-lipoxygenase, 5-lipoxygenase, 5-LO, and 5-LOX). ALOX5 metabolizes arachidonic acid to its hydroperoxide derivative, arachidonic acid 5-hydroperoxide i.e. 5"S"-hydroperoxy-6"E",8"Z",11"Z",14"Z"-eicosatetraenoic acid (5("S")-HpETE). 5-("S")-HpETE may then be released and rapidly converted to 5("S")-HETE by ubiquitous cellular peroxidases:
Cells metabolize 5-("S")-HETE in other ways. They may use: