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A bioanalytical equivalent (BEQ) is a unit of measure in the field of bioassays. It is used for example in the bioassay CALUX for testing dioxins and dioxin-like compounds. [1]
Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of long-lived polyhalogenated organic compounds that are primarily anthropogenic, and contribute toxic, persistent organic pollution in the environment.
BEQ is an abbreviation for:
The term dilution assay is generally used to designate a special type of bioassay in which one or more preparations are administered to experimental units at different dose levels inducing a measurable biological response. The dose levels are prepared by dilution in a diluent that is inert in respect of the response. The experimental units can for example be cell-cultures, tissues, organs or living animals. The biological response may be quantal or quantitative. The goal is to relate the response to the dose, usually by interpolation techniques, and in many cases to express the potency/activity of the test preparation(s) relative to a standard of known potency/activity.
Polychlorinated dibenzofurans (PCDFs) are a family of organic compounds with one or several of the hydrogens in the dibenzofuran structure replaced by chlorines. For example, 2,3,7,8-tetrachlorodibenzofuran (TCDF) has chlorine atoms substituted for each of the hydrogens on the number 2, 3, 7, and 8 carbons. Polychlorinated dibenzofurans with chlorines at least in positions 2,3,7 and 8 are much more toxic than the parent compound dibenzofurane, with properties and chemical structures similar to polychlorinated dibenzodioxins. These groups together are often inaccurately called dioxins. They are known developmental toxicants, and suspected human carcinogens. PCDFs tend to co-occur with polychlorinated dibenzodioxins (PCDDs). PCDFs can be formed by pyrolysis or incineration at temperatures below 1200 °C of chlorine containing products, such as PVC, PCBs, and other organochlorides, or of non-chlorine containing products in the presence of chlorine donors. Dibenzofurans are known persistent organic pollutants (POP), classified among the dirty dozen in the Stockholm Convention on Persistent Organic Pollutants.
Dioxins and dioxin-like compounds (DLCs) are a group of chemical compounds that are persistent organic pollutants (POPs) in the environment. They are mostly by-products of burning or various industrial processes or, in the case of dioxin-like PCBs and PBBs, unwanted minor components of intentionally produced mixtures.
Chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) are a group of compounds comprising polycyclic aromatic hydrocarbons with two or more aromatic rings and one or more chlorine atoms attached to the ring system. Cl-PAHs can be divided into two groups: chloro-substituted PAHs, which have one or more hydrogen atoms substituted by a chlorine atom, and chloro-added Cl-PAHs, which have two or more chlorine atoms added to the molecule. They are products of incomplete combustion of organic materials. They have many congeners, and the occurrences and toxicities of the congeners differ. Cl-PAHs are hydrophobic compounds and their persistence within ecosystems is due to their low water solubility. They are structurally similar to other halogenated hydrocarbons such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). Cl-PAHs in the environment are strongly susceptible to the effects of gas/particle partitioning, seasonal sources, and climatic conditions.
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a polychlorinated dibenzo-p-dioxin (sometimes shortened, though inaccurately, to simply 'dioxin') with the chemical formula C12H4Cl4O2. Pure TCDD is a colorless solid with no distinguishable odor at room temperature. It is usually formed as an unwanted product in burning processes of organic materials or as a side product in organic synthesis.
Toxic equivalency factor (TEF) expresses the toxicity of dioxins, furans and PCBs in terms of the most toxic form of dioxin, 2,3,7,8-TCDD. The toxicity of the individual congeners may vary by orders of magnitude.
Altrenogest, sold under the brand names Swinemate and Altren manufactured by Aurora Pharmaceutical and Regumate manufactured by Merck, is a progestin of the 19-nortestosterone group which is widely used in veterinary medicine to suppress or synchronize estrus in horses and pigs. It is available for veterinary use in both Europe and the United States.
Chemical Activated LUciferase gene eXpression (CALUX) is a ligand-dependent nuclear receptor-based bioassay used in the detection of specific chemicals or classes of chemicals in samples. It consists of a modified cell line that has been stably transfected with a DNA construct with a luciferase reporter gene under control of receptor-specific DNA response elements that can stimulate transcription of the inserted luciferase gene and produce the light-generating enzyme which can be easily measured. The DNA response elements can be varied in order to provide binding sites for other receptors that are regulated by a chemical or class of chemicals of interest that want to be detected. Thus, numerous CALUX bioassays have been developed for detection of diverse chemicals of interest. Most applications have been directed toward the detection of environmentally harmful chemicals, such as those affecting the endocrine system.
3β-Dihydroprogesterone (3β-DHP), also known as 3β-hydroxyprogesterone, or pregn-4-en-3β-ol-20-one, is an endogenous steroid. It is biosynthesized by 3β-hydroxysteroid dehydrogenase from progesterone. Unlike 3α-dihydroprogesterone (3α-DHP), 3β-DHP does not act as a positive allosteric modulator of the GABAA receptor, which is in accordance with the fact that other 3β-hydroxylated progesterone metabolites such as isopregnanolone and epipregnanolone similarly do not act as potentiators of this receptor and instead inhibit it as well as reverse the effects of potentiators like allopregnanolone. 3β-DHP has been reported to possess about the same potency as progesterone in a bioassay of progestogenic activity, whereas 3α-DHP was not assessed.
Ro 6-3129, also known as 16α-ethylthio-6-dehydroretroprogesterone or as 16α-ethylthio-9β,10α-pregna-4,6-diene-3,20-dione, as well as 16α-ethylthiodydrogesterone, is a progestogen of the retroprogesterone group which was developed by Roche but was never marketed. It shows greater potency than dydrogesterone in bioassays.
11-Dehydroprogesterone, also known as pregna-4,11-diene-3,20-dione, is a steroidal progestin that was never marketed. It was found to be 2- to 3-fold as potent as progesterone as a progestogen in animal bioassays, although other studies found them to be equivalent in potency. 11-Dehydroprogesterone has been studied in women. It was discovered in the 1930s or 1940s, and was one of the earliest synthetic progestogens.
5α-Dihydronorethisterone is a major active metabolite of norethisterone (norethindrone). Norethisterone is a progestin with additional weak androgenic and estrogenic activity. 5α-DHNET is formed from norethisterone by 5α-reductase in the liver and other tissues.
A bioassay is an analytical method to determine the concentration or potency of a substance by its effect on living animals or plants, or on living cells or tissues. A bioassay can be either quantal or quantitative, direct or indirect. If the measured response is binary, the assay is quantal; if not, it is quantitative.
Progesterone 3-acetyl enol ether, also known as progesterone acetate, as well as 3-acetoxypregna-3,5-dien-20-one, is a progestin which was never marketed. It was reported to possess similar potency to progesterone and hydroxyprogesterone caproate in the rabbit endometrial carbonic anhydrase test, a bioassay of progestogenic activity. In addition, it was able to maintain pregnancy in animals. Progesterone 3-acetyl enol ether is closely related to quingestrone, which is also known as progesterone 3-cyclopentyl enol ether and was formerly marketed as an oral contraceptive.
18-Methylsegesterone acetate is a progestin medication of the 19-norprogesterone group which was never marketed. It was first described in a patent in 1997 and then in a literature paper in 2003. 18-Methyl-SGA is the C18 methyl or C13β ethyl derivative of segesterone acetate, and shows 3 to 10 times the progestogenic potency of SGA in bioassays. This is analogous to the case of the 19-nortestosterone progestin norethisterone and its 18-methyl derivative levonorgestrel, the latter showing substantially increased potency relative to the former similarly. As SGA is already one of the most potent progestins to have been developed, with 100-fold the potency of progesterone and 10-fold the potency of levonorgestrel in bioassays, 18-methyl-SGA is an extremely potent progestogen, among if not the most potent known.
Tetrahydrocannabiphorol (THCP) is a potent phytocannabinoid, a CB1 and CB2 agonist which was known as a synthetic homologue of THC, but for the first time in 2019 was isolated as a natural product in trace amounts from Cannabis sativa. It is structurally similar to Δ9-THC, the main active component of cannabis, but with the pentyl side chain extended to heptyl. Since it has a longer side chain, its cannabinoid effects are "far higher than Δ9-THC itself." Tetrahydrocannabiphorol has a reported binding affinity of 1.2 nM at CB1, approximately 33 times that of Δ9-THC (40 nM at CB1).
Ethandrostate, also known as ethinylandrostenediol 3β-cyclohexanepropionate, is a synthetic steroidal estrogen and ester of ethinylandrostenediol (17α-ethynyl-5-androstenediol) which was developed and studied in people with certain cancers like breast cancer and prostate cancer in the 1950s but was never marketed. Although far less potent by weight than estradiol or estrone, ethandrostate produces estrogenic effects in the vagina, uterus, and mammary glands as well as antigonadotropic and secondary antiandrogenic effects like testicular and prostate atrophy in both animals and humans. Ethandrostate was assessed in humans as an aqueous suspension by intramuscular injection at doses of 100 to 200 mg/day or 100 mg three times per week and by mouth at a dose of 25 mg four times per day. It shows much greater antigonadotropic potency relative to general estrogenic potency in animals when compared with other estrogens. However, this doesn't seem to be the case in humans. In addition to its estrogenic activity, ethandrostate has very weak androgenic activity that manifests only at doses much higher than its estrogenic activity.
