|
Fertilysin
Fertilysin (WIN 18446) is an experimental drug that was studied as a male contraceptive, but was never marketed. It interferes with testicular production of retinoic acid, which is necessary for spermatogenesis. In studies in male animals including rodents, wolves, cats, and shrews, fertilysin was found to be a safe, effective, and reversible oral contraceptive. However, the side effects observed in human clinical trials preclude its use in men. Fertilysin was originally studied in the 1950s for its potential amebicidal effects. When the anti-spermatogenesis effects were observed in animal studies, the focus of the research turned towards its potential use as a contraceptive. Fertilysin is an inhibitor of aldehyde dehydrogenase 1a2, a member of the aldehyde dehydrogenase family of enzymes. Inhibition of this enzyme blocks the production of retinoic acid which prevents the production of sperm. Because aldehyde dehydrogenases are also involved in the metabolism of ethanol, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Male Contraceptive
Male contraceptives, also known as male birth control, are methods of preventing pregnancy by interrupting the function of sperm. The main forms of male Birth control, contraception available today are condoms, vasectomy, and Coitus interruptus, withdrawal, which together represented 20% of global contraceptive use in 2019. New forms of male contraception are in Clinical trial, clinical and Preclinical development, preclinical stages of research and development, but as of 2025, none have reached Approved drug, regulatory approval for widespread use. They could be available before 2030, assuming smooth development and clinical trials. These new methods include topical creams, daily pills, injections, long-acting implants, and external devices, and these products have both hormonal and non-hormonal mechanisms of action. Some of these new contraceptives could even be unisex, or usable by any person, because they could theoretically incapacitate mature sperm in the man's body before ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinoic Acid
Retinoic acid (simplified nomenclature for all-''trans''-retinoic acid) is a metabolite of vitamin A1 (all-''trans''-retinol) that is required for embryonic development, male fertility, regulation of bone growth and immune function. All-''trans''-retinoic acid is required for chordate animal development, which includes all higher animals from fish to humans. During early embryonic development, all-''trans''-retinoic acid generated in a specific region of the embryo helps determine position along the embryonic anterior/posterior axis by serving as an intercellular signaling molecule that guides development of the posterior portion of the embryo. It acts through Hox genes, which ultimately control anterior/posterior patterning in early developmental stages. In adult tissues, the activity of endogenous retinoic acid appears limited to immune function and male fertility. All-''trans''-retinoic acid is the major occurring retinoic acid, while isomers like 13-''cis''- and 9-''cis''-r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatogenesis
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testicle. This process starts with the Mitosis, mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called Spermatogonial Stem Cells, spermatogonial stem cells. The mitotic division of these produces two types of cells. Type A cells replenish the stem cells, and type B cells differentiate into primary spermatocytes. The primary spermatocyte divides meiotically (Meiosis I) into two secondary spermatocytes; each secondary spermatocyte divides into two equal haploid spermatids by Meiosis II. The spermatids are transformed into spermatozoa (sperm) by the process of spermiogenesis. These develop into mature spermatozoa, also known as sperm, sperm cells. Thus, the primary spermatocyte gives rise to two cells, the secondary spermatocytes, and the two secondary spermatocytes by their subdivision produce four spermatoz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amebicide
An amebicide (or amoebicide) is an agent that is destructive to amoeba, especially parasitic amoeba that cause amoebiasis. Entamoeba * Metronidazole, or a related drug such as Tinidazole, Secnidazole or Ornidazole, is used to destroy amoebae that have invaded tissue. * Several drugs are available for treating intestinal infections, the most effective of which has been shown to be Paromomycin (also known as Humatin). ''E. histolytica'' infections occur in both the intestine and (in people with symptoms) in tissue of the intestine and/or liver. As a result, both tissue and luminal drugs are needed to treat the infection, one for each location. Metronidazole is usually given first, followed by Paromomycin or Diloxanide. ''E. dispar'' does not require treatment, but many laboratories (even in the developed world) do not have the facilities to distinguish this from ''E. histolytica''. Tissue amebicides Metronidazole, or a related drug such as tinidazole, secnidazole or ornidazole ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALDH1A2
Aldehyde dehydrogenase 1 family, member A2, also known as ALDH1A2 or retinaldehyde dehydrogenase 2 (RALDH2), is an enzyme that in humans is encoded by the ''ALDH1A2'' gene. Function ALDH1a2 belongs to the aldehyde dehydrogenase family of proteins, and specifically the ALDH1 family. The product of this gene, ALDH1a2, is an enzyme that catalyzes the synthesis of all-trans retinoic acid (RA) from retinaldehyde in a NAD-dependent manner. Retinoic acid, the active derivative of vitamin A (retinol), is a retinoid nuclear receptor ligand that functions in developing and adult tissues. ALDH1a2 is critical to fetal development by activating the RAR nuclear receptors. Studies of ALDH1a2 in mice suggest that this enzyme and the cytochrome CYP26A1 enzyme coordinate local embryonic retinoic acid levels that facilitate posterior organ development and prevent spina bifida. In adult tissues, ALDH1a2 is known to regulate immune tolerance in the colon and other mucosal tissues by generati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldehyde Dehydrogenase
Aldehyde dehydrogenases () are a group of enzymes that catalyse the oxidation of aldehydes. They convert aldehydes (R–C(=O)) to carboxylic acids (R–C(=O)). The oxygen comes from a water molecule. To date, nineteen ALDH genes have been identified within the human genome. These genes participate in a wide variety of biological processes including the detoxification of exogenously and endogenously generated aldehydes. Function Aldehyde dehydrogenase is a polymorphic enzyme responsible for the oxidation of aldehydes to carboxylic acids. There are three different classes of these enzymes in mammals: class 1 (low ''K''m, cytosolic), class 2 (low ''K''m, mitochondrial), and class 3 (high ''K''m, such as those expressed in tumors, stomach, and cornea). In all three classes, constitutive and inducible forms exist. ALDH1 and ALDH2 are the most important enzymes for aldehyde oxidation, and both are tetrameric enzymes composed of 54 kDa subunits. These enzymes are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disulfiram
Disulfiram is a medication used to support the treatment of chronic alcoholism by producing an acute sensitivity to ethanol (drinking alcohol). Disulfiram works by Enzyme inhibition, inhibiting the enzyme aldehyde dehydrogenase (specifically ALDH2), causing many of the effects of a hangover to be felt immediately following alcohol (drug), alcohol consumption. Disulfiram plus alcohol, even small amounts, produces flushing, throbbing in the head and neck, a throbbing headache, respiratory difficulty, nausea, copious vomiting, sweating, thirst, chest pain, palpitation, dyspnea, shortness of breath, hyperventilation, tachycardia, fast heart rate, hypotension, low blood pressure, Syncope (medicine), fainting, marked uneasiness, weakness, vertigo, blurred vision, and confusion. In severe reactions there may be respiratory depression, cardiovascular collapse, arrhythmia, abnormal heart rhythms, myocardial infarction, heart attack, acute congestive heart failure, unconsciousness, convulsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abandoned Drugs
Abandon, abandoned, or abandonment may refer to: Common uses * Abandonment (emotional), a subjective emotional state in which people feel undesired, left behind, insecure, or discarded * Abandonment (legal), a legal term regarding property ** Child abandonment, the extralegal abandonment of children ** Lost, mislaid, and abandoned property, legal status of property after abandonment and rediscovery * Abandonment (mysticism) Art, entertainment, and media Film * ''Abandon'' (film), a 2002 film starring Katie Holmes * ''Abandoned'' (1949 film), starring Dennis O'Keefe * ''Abandoned'' (1955 film), the English language title of the Italian war film ''Gli Sbandati'' * ''Abandoned'' (2001 film), a Hungarian film * ''Abandoned'' (2010 film), starring Brittany Murphy * ''Abandoned'' (2015 film), a television movie about the shipwreck of the ''Rose-Noëlle'' in 1989 * ''Abandoned'' (2022 film), starring Emma Roberts * ''The Abandoned'' (1945 film), a 1945 Mexican film * ''The Aba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amides
In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula , where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, as in asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid () with the hydroxyl group () replaced by an amino group (); or, equivalently, an acyl (alkanoyl) group () joined to an amino group. Common amides are formamide (), acetamide (), benzamide (), and dimethylformamide (). Some uncommon examples of amides are ''N''-chloroacetamide () and chloroformamide (). Amides are qualified as primary, secondary, and tertiary according to the number of acyl groups bounded to the nitrogen atom. Nomenclature The core of amides is called the amide group (specifically, carboxamide group). In the usual no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
