Melanins
Monophenol Monooxygenase
Melanocytes
Naphthols
Dihydroxyphenylalanine
Albinism
Exophiala
Hyperpigmentation
Cysteinyldopa
Laccase
Hair
Agaricales
Catechol Oxidase
Cryptococcus neoformans
Melanoma, Experimental
Melanosis
Microphthalmia-Associated Transcription Factor
Feathers
Melanoma
Pigmentation Disorders
Sepia
Albinism, Oculocutaneous
Chromatophores
Melanoma, Amelanotic
Mesons
Actinium
Levodopa
alpha-MSH
Alternaria
Hypothalamic Hormones
Intramolecular Oxidoreductases
Cellular localization and role of prohormone convertases in the processing of pro-melanin concentrating hormone in mammals. (1/1585)
Melanin concentrating hormone (MCH) and neuropeptide EI (NEI) are two peptides produced from the same precursor in mammals, by cleavage at the Arg145-Arg146 site and the Lys129-Arg130 site, respectively. We performed co-localization studies to reveal simultaneously the expression of MCH mRNA and proconvertases (PCs) such as PC1/3 or PC2. In the rat hypothalamus, PC2 was present in all MCH neurons, and PC1/3 was present in about 15-20% of these cells. PC1/3 or PC2 was not found in MCH-positive cells in the spleen. In GH4C1 cells co-infected with vaccinia virus (VV):pro-MCH along with VV:furin, PACE4, PC1/3, PC2, PC5/6A, PC5/6B, or PC7, we observed only efficient cleavage at the Arg145-Arg146 site to generate mature MCH. Co-expression of pro-MCH together with PC2 and 7B2 resulted in very weak processing to NEI. Comparison of pro-MCH processing patterns in PC1/3- or PC2-transfected PC12 cells showed that PC2 but not PC1/3 generated NEI. Finally, we analyzed the pattern of pro-MCH processing in PC2 null mice. In the brain of homozygotic mutants, the production of mature NEI was dramatically reduced. In contrast, MCH content was increased in the hypothalamus of PC2 null mice. In the spleen, a single large MCH-containing peptide was identified in both wild type and PC2 null mice. Together, our data suggest that pro-MCH is processed differently in the brain and in peripheral organs of mammals. PC2 is the key enzyme that produces NEI, whereas several PCs may cleave at the Arg145-Arg146 site to generate MCH in neuronal cell types. (+info)Effects of lithium on pigmentation in the embryonic zebrafish (Brachydanio rerio). (2/1585)
Pigment cell precursors of the embryonic zebrafish give rise to melanophores, xanthophores and/or iridophores. Cell signaling mechanisms related to the development of pigmentation remain obscure. In order to examine the mechanisms involved in pigment cell signaling, we treated zebrafish embryos with various activators and inhibitors of signaling pathways. Among those chemicals tested, LiCl and LiCl/forskolin had a stimulatory effect on pigmentation, most notable in the melanophore population. We propose that the inositol phosphate (IP) pathway, is involved in pigment pattern formation in zebrafish through its involvement in the: (1) differentiation/proliferation of melanophores; (2) dispersion of melanosomes; and/or (3) synthesis/deposition of melanin. To discern at what level pigmentation was being effected we: (1) counted the number of melanophores in control and experimental animals 5 days after treatment; (2) measured tyrosinase activity and melanin content; and (3) employed immunoblotting techniques with anti-tyrosine-related protein-2 and anti-melanocyte-specific gene-1 as melanophore-specific markers. Although gross pigmentation increased dramatically in LiCl- and LiCl/forskolin treated embryos, the effect on pigmentation was not due to an increase in the proliferation of melanophores, but was possibly through an increase in melanin synthesis and/or deposition. Collectively, results from these studies suggest the involvement of an IP-signaling pathway in the stimulation of pigmentation in embryonic zebrafish through the synthesis/deposition of melanin within the neural crest-derived melanophores. (+info)The effect of the orexins on food intake: comparison with neuropeptide Y, melanin-concentrating hormone and galanin. (3/1585)
Orexin-A and orexin-B (the hypocretins) are recently described neuropeptides suggested to have a physiological role in the regulation of food intake in the rat. We compared the orexigenic effect of the orexins administered intracerebroventricular (ICV) with other known stimulants of food intake, one strong, neuropeptide Y (NPY), and two weaker, melanin-concentrating hormone (MCH) and galanin. Orexin-A consistently stimulated food intake, but orexin-B only on occasions. Both peptides stimulated food intake significantly less than NPY, but to a similar extent to MCH (2 h food intake: NPY 3 nmol, 7.2+/-0.9 g vs saline, 1.5+/-0.2 g, P<0.001, MCH 3 nmol, 3.2+/-0.8 g vs saline, P<0.01, orexin-B 30 nmol, 2. 6+/-0.5 g vs saline, P=0.11) and to galanin (1 h food intake: galanin 3 nmol, 2.0+/-0.4 g vs saline, 0.8+/-0.2 g, P<0.05, orexin-A 3 nmol 2.2+/-0.4 g vs saline, P<0.01; 2 hour food intake: orexin-B 3 nmol, 2.4+/-0.3 g vs saline, 1.3+/-0.2 g, P<0.05). Following ICV orexin-A, hypothalamic c-fos, a maker of neuronal activation, was highly expressed in the paraventricular nucleus (PVN), and the arcuate nucleus (P<0.005 for both). IntraPVN injection of orexin-A stimulated 2 h food intake by one gram (orexin-A 0.03 nmol, 1.6+/-0. 3 g vs saline, 0.5+/-0.3 g, P<0.005). These findings support the suggestion that the orexins stimulate food intake. However, this effect is weak and may cast doubt upon their physiological importance in appetite regulation in the rat. (+info)Topical all-trans retinoic acid augments ultraviolet radiation-induced increases in activated melanocyte numbers in mice. (4/1585)
We have previously shown that daily application of 0.05% retinoic acid to the backs of lightly pigmented, hairless HRA:Skh-2 mice increases melanogenesis resulting from exposure to solar-simulated ultraviolet radiation. In this study we show that as early as 1 wk following commencement of treatment, there is a 2- fold increase in the number of epidermal 3,4-dihydroxyphenylalanine positive melanocytes in retinoic acid and ultraviolet radiation treated HRA:Skh-2 mice compared with mice that received ultraviolet radiation only. This increased to a 2.9-fold difference by 6 wk. Retinoic acid also augmented ultraviolet radiation-stimulated melanogenesis, with a 4-fold increase being observed after only 2 wk. These findings were also seen in C57BL mice. Ultraviolet radiation and retinoic acid needed to be applied to the same skin site for the augmentation in melanocyte activation to occur. Ultraviolet B rather than ultraviolet A was mainly responsible for melanogenesis and the retinoic acid primarily increased ultraviolet B-induced melanogenesis. Furthermore, retinoic acid on it's own, in the absence of ultraviolet radiation caused a small but statistically significant increase in 3,4-dihydroxyphenylalanine positive melanocyte numbers and melanogenesis. Thus topical retinoic acid is a potent modulator of melanocyte activation. Alone it is able to increase the number of activated epidermal melanocytes and make melanocytes more sensitive to activation by ultraviolet B. (+info)Tumor necrosis factor alpha-mediated inhibition of melanogenesis is dependent on nuclear factor kappa B activation. (5/1585)
Melanogenesis is a physiological process resulting in the synthesis of melanin pigments which play a crucial protective role against skin photocarcinogenesis. In vivo, solar ultraviolet light triggers the secretion of numerous keratinocyte-derived factors that are implicated in the regulation of melanogenesis. Among these, tumor necrosis factor alpha (TNFalpha), a cytokine implicated in the pro-inflammatory response, down-regulates pigment synthesis in vitro. In this report, we aimed to determine the molecular mechanisms by which this cytokine inhibits melanogenesis in B16 melanoma cells. First, we show that TNFalpha inhibits the activity and protein expression of tyrosinase which is the key enzyme of melanogenesis. Further, we demonstrate that this effect is subsequent to a down-regulation of the tyrosinase promoter activity in both basal and cAMP-induced melanogenesis. Finally, we present evidence indicating that the inhibitory effect of TNFalpha on melanogenesis is dependent on nuclear factor kappa B (NFkappaB) activation. Indeed, overexpression of this transcription factor in B16 cells is sufficient to inhibit tyrosinase promoter activity. Furthermore, a mutant of inhibitory kappa B (IkappaB), that prevents NFkappaB activation, is able to revert the effect of TNFalpha on the tyrosinase promoter activity. Taken together, our results clarify the mechanisms by which TNFalpha inhibits pigmentation and point out the key role of NFkappaB in the regulation of melanogenesis. (+info)Purification and characterization of a secreted laccase of Gaeumannomyces graminis var. tritici. (6/1585)
We purified a secreted fungal laccase from filtrates of Gaeumannomyces graminis var. tritici cultures induced with copper and xylidine. The active protein had an apparent molecular mass of 190 kDa and yielded subunits with molecular masses of 60 kDa when denatured and deglycosylated. This laccase had a pI of 5.6 and an optimal pH of 4.5 with 2,6-dimethoxyphenol as its substrate. Like other, previously purified laccases, this one contained several copper atoms in each subunit, as determined by inductively coupled plasma spectroscopy. The active enzyme catalyzed the oxidation of 2, 6-dimethoxyphenol (Km = 2.6 x 10(-5) +/- 7 x 10(-6) M), catechol (Km = 2.5 x 10(-4) +/- 1 x 10(-5) M), pyrogallol (Km = 3.1 x 10(-4) +/- 4 x 10(-5) M), and guaiacol (Km = 5.1 x 10(-4) +/- 2 x 10(-5) M). In addition, the laccase catalyzed the polymerization of 1, 8-dihydroxynaphthalene, a natural fungal melanin precursor, into a high-molecular-weight melanin and catalyzed the oxidation, or decolorization, of the dye poly B-411, a lignin-like polymer. These findings indicate that this laccase may be involved in melanin polymerization in this phytopathogen's hyphae and/or in lignin depolymerization in its infected plant host. (+info)Possible involvement of proteolytic degradation of tyrosinase in the regulatory effect of fatty acids on melanogenesis. (7/1585)
The purpose of this study was to investigate the mechanism of fatty acid-induced regulation of melanogenesis. An apparent regulatory effect on melanogenesis was observed when cultured B16F10 melanoma cells were incubated with fatty acids, i.e., linoleic acid (unsaturated, C18:2) decreased melanin synthesis while palmitic acid (saturated, C16:0) increased it. However, mRNA levels of the melanogenic enzymes, tyrosinase, tyrosinase-related protein 1 (TRP1), and tyrosinase-related protein 2 (TRP2), were not altered. Regarding protein levels of these enzymes, the amount of tyrosinase was decreased by linoleic acid and increased by palmitic acid, whereas the amounts of TRP1 and TRP2 did not change after incubation with fatty acids. Pulse-chase assay by [35S]methionine metabolic labeling revealed that neither linoleic acid nor palmitic acid altered the synthesis of tyrosinase. Further, it was shown that linoleic acid accelerated, while palmitic acid decelerated, the proteolytic degradation of tyrosinase. These results suggest that modification of proteolytic degradation of tyrosinase is involved in regulatory effects of fatty acids on melanogenesis in cultured melanoma cells. (+info)Structure and developmental expression of the ascidian TRP gene: insights into the evolution of pigment cell-specific gene expression. (8/1585)
The tyrosinase family in vertebrates consists of three related melanogenic enzymes: tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2. These proteins control melanin production in pigment cells and play a crucial role in determining vertebrate coloration. We have isolated a gene from the ascidian Halocynthia roretzi which encodes a tyrosinase-related protein (HrTRP) with 45-49% identity with vertebrate TRP-1 and TRP-2. The expression of the HrTRP gene in pigment lineage a8.25 cells starts at the early-mid gastrula stage, which coincides with the stage when these cells are determined as pigment precursor cells; therefore, it provides the earliest pigment lineage-specific marker, which enables us to trace the complete cell lineage leading to two pigment cells in the larval brain. In addition, the expression pattern of the HrTRP gene appears to share similar characteristics with the mouse TRP-2 gene although structurally the HrTRP gene is more closely related to mammalian TRP-1 genes. Based on these observations and on results from molecular phylogenetic and hybridization analyses, we suggest that triplication of the tyrosinase family occurred during the early radiation of chordates. Initially, duplication of an ancestral tyrosinase gene produced a single TRP gene before the urochordate and cephalochordate-vertebrate divergence, and a subsequent duplication of the ancestral TRP gene in the vertebrate lineage gave rise to two TRP genes before the emergence of teleost fishes. Evolution of the melanin synthetic pathway and possible phylogenetic relationships among chordate pigment cells that accommodate the metabolic process are discussed. Dev Dyn 1999;215:225-237. (+info)Melanins are a group of pigments produced by melanocytes, which are specialized cells found in the skin, hair, and eyes. There are two main types of melanins: eumelanin and pheomelanin. Eumelanin is the darker pigment responsible for the color of black, brown, and red hair and skin. It also provides protection against harmful ultraviolet (UV) radiation from the sun. Pheomelanin is the lighter pigment responsible for the color of blonde, red, and light brown hair and skin. It does not provide as much protection against UV radiation as eumelanin. Melanins play an important role in the body's defense against UV radiation, as they can absorb and scatter UV light, preventing it from penetrating the skin and causing damage to DNA. They also play a role in regulating skin pigmentation and protecting against skin cancer.
Monophenol monooxygenase (MMO) is an enzyme that catalyzes the oxidation of monophenols to o-diphenols. It is involved in the biosynthesis of various secondary metabolites, including flavonoids, lignans, and alkaloids, in plants and microorganisms. MMO is also found in some bacteria and fungi, where it plays a role in the degradation of aromatic compounds. In the medical field, MMO has been studied for its potential use in the treatment of various diseases, including cancer, cardiovascular disease, and neurodegenerative disorders.
Naphthols are a class of organic compounds that contain a naphthalene ring with a hydroxyl group (-OH) attached to it. They are commonly used in the medical field as dyes, stains, and disinfectants. Some naphthols are also used as pharmaceuticals, such as naphthol AS-D chloroacetate, which is used as a topical antiseptic and disinfectant. Other naphthols, such as 2-naphthol, have been studied for their potential anti-inflammatory and analgesic effects. However, some naphthols, such as 1-naphthol, are considered hazardous and can cause skin irritation, respiratory problems, and other health issues if they are inhaled or ingested.
Dihydroxyphenylalanine, also known as DOPA, is a chemical compound that is a precursor to the neurotransmitter dopamine. It is produced in the body from the amino acid tyrosine, which is found in many foods, including meat, dairy products, and some vegetables. In the medical field, DOPA is used to treat certain neurological conditions, such as Parkinson's disease, which is characterized by a deficiency of dopamine in the brain. DOPA is given orally or intravenously to increase the levels of dopamine in the brain and improve symptoms such as tremors, stiffness, and difficulty with movement. DOPA is also used to treat other conditions, such as Huntington's disease and some forms of depression. It is important to note that DOPA can have side effects, including nausea, vomiting, and dizziness, and it should only be used under the supervision of a healthcare professional.
Albinism is a genetic disorder that affects the production of melanin, the pigment that gives color to the skin, hair, and eyes. People with albinism have little or no melanin, which can result in lighter skin, hair, and eyes. There are several types of albinism, including oculocutaneous albinism (OCA), which affects the skin, hair, and eyes, and ocular albinism (OA), which affects only the eyes. OCA is further divided into three subtypes: OCA1, OCA2, and OCA3, each with different symptoms and severity. People with albinism are at an increased risk of skin damage from the sun, vision problems, and sensitivity to light. They may also have difficulty with social interactions due to their appearance and may face discrimination or prejudice. Treatment for albinism typically involves managing symptoms and providing support for individuals and families affected by the condition.
Hyperpigmentation is a medical condition characterized by an increase in the amount of melanin, the pigment responsible for skin color, in certain areas of the skin. This can result in dark or discolored patches on the skin, which may be uniform or irregular in shape and size. Hyperpigmentation can be caused by a variety of factors, including exposure to the sun, hormonal changes, certain medications, and skin injuries or infections. It is more common in people with darker skin tones, but can affect anyone. There are several types of hyperpigmentation, including melasma, freckles, age spots, and post-inflammatory hyperpigmentation. Treatment options for hyperpigmentation depend on the underlying cause and the severity of the condition. Common treatments include topical creams, chemical peels, laser therapy, and microdermabrasion.
Cysteinyldopa is a compound that is formed as a byproduct of the metabolism of the amino acid tyrosine. It is produced when tyrosine is converted into dopamine, which is a neurotransmitter that plays a role in the regulation of movement, mood, and other functions. Cysteinyldopa is then further metabolized into other compounds, including homovanillic acid and vanillylmandelic acid, which can be measured in the urine or blood to help diagnose certain medical conditions, such as Parkinson's disease and pheochromocytoma.
Laccase is an enzyme that belongs to the family of multicopper oxidases. It is produced by a variety of organisms, including fungi, bacteria, and plants. In the medical field, laccase has been studied for its potential applications in various areas, including: 1. Bioremediation: Laccase can break down a wide range of environmental pollutants, including phenols, dyes, and pesticides. It has been used in bioremediation to clean up contaminated soil and water. 2. Wastewater treatment: Laccase can be used to degrade organic pollutants in wastewater, making it a potential alternative to traditional chemical treatments. 3. Bioprinting: Laccase has been used in bioprinting to create 3D structures using living cells. It can crosslink biopolymers, such as alginate, to create stable structures. 4. Cancer treatment: Laccase has been shown to have anti-cancer properties and has been studied as a potential therapeutic agent for various types of cancer. 5. Drug delivery: Laccase can be used to modify the surface of drug delivery vehicles, such as nanoparticles, to improve their targeting and efficacy. Overall, laccase has a wide range of potential applications in the medical field, and ongoing research is exploring its full potential.
In the medical field, Agaricales is a taxonomic order of fungi that includes a diverse group of mushrooms and other fungi. The order Agaricales is characterized by the presence of a cap and stem, and the absence of a true veil or gill structure on the underside of the cap. Many species of Agaricales are edible and are commonly consumed as food, while others are poisonous and can cause serious illness or death if ingested. Some species of Agaricales are also used in traditional medicine for their medicinal properties, such as the use of certain species of mushrooms to treat cancer or other diseases. In addition to their culinary and medicinal uses, Agaricales are also important in the field of mycology, the study of fungi. Many species of Agaricales are used as model organisms for studying fungal genetics, evolution, and ecology.
Catechol oxidase is an enzyme that catalyzes the oxidation of catecholamines, such as dopamine and norepinephrine, to their corresponding quinones. This enzyme plays a crucial role in the metabolism of catecholamines in the body, particularly in the brain and adrenal gland. In the medical field, catechol oxidase is often studied in the context of various neurological and psychiatric disorders, such as Parkinson's disease, schizophrenia, and depression, where there is often an imbalance in catecholamine levels. Additionally, catechol oxidase inhibitors are sometimes used as medications to treat certain conditions, such as hypertension and heart failure, by blocking the enzyme's activity and reducing the breakdown of catecholamines.
Cryptococcus neoformans is a type of fungus that can cause a serious infection in humans and animals. It is commonly found in the environment, particularly in soil and bird droppings, and can be inhaled into the lungs. The fungus can also cause infections in other parts of the body, such as the brain and spinal cord, and can be life-threatening if left untreated. Infections caused by Cryptococcus neoformans are typically treated with antifungal medications.
Melanoma, Experimental refers to a type of research being conducted to develop new treatments or therapies for melanoma, a type of skin cancer. These experimental treatments may involve the use of new drugs, vaccines, or other interventions that have not yet been approved for use in humans. The goal of this research is to find more effective and safer ways to treat melanoma and improve outcomes for patients with this disease. Experimental melanoma treatments are typically tested in clinical trials, where they are given to a small group of patients to evaluate their safety and effectiveness before they can be approved for widespread use.
Melanosis is a medical term used to describe an increase in the amount of melanin, the pigment that gives color to the skin, hair, and eyes. It can occur in various parts of the body, including the skin, mucous membranes, and internal organs. In the skin, melanosis can manifest as hyperpigmentation, which is an uneven distribution of melanin that results in dark patches or patches of discoloration. Melanosis can be caused by a variety of factors, including exposure to the sun, hormonal changes, certain medications, and genetic factors. Melanosis can also occur in the mucous membranes, such as the mouth and throat, where it is known as oral melanosis. This condition can be caused by a variety of factors, including tobacco use, excessive alcohol consumption, and certain medications. In the internal organs, melanosis can occur in the gastrointestinal tract, where it is known as gastrointestinal melanosis. This condition is usually associated with the presence of melanoma, a type of cancer that begins in the melanocytes, the cells that produce melanin. Overall, melanosis is a benign condition that does not typically cause any symptoms or health problems. However, in some cases, it may be a sign of an underlying medical condition, such as melanoma, and should be evaluated by a healthcare provider.
Microphthalmia-Associated Transcription Factor (MITF) is a transcription factor that plays a critical role in the development and function of melanocytes, the cells responsible for producing the pigment melanin. MITF is also involved in the development of other cell types, including osteoclasts, macrophages, and dendritic cells. In the medical field, MITF is often studied in the context of diseases that affect melanocytes, such as melanoma, a type of skin cancer. MITF is also involved in the development of other types of cancer, including breast cancer and glioblastoma. Mutations in the MITF gene can lead to a rare genetic disorder called Waardenburg syndrome, which is characterized by hearing loss, pigmentation abnormalities, and other developmental issues. MITF is also involved in the regulation of the immune system, and changes in MITF expression have been linked to autoimmune diseases and inflammatory disorders.
Melanoma is a type of skin cancer that begins in the cells that produce the pigment melanin. It is the most dangerous type of skin cancer, as it has the potential to spread to other parts of the body and be difficult to treat. Melanoma can occur in any part of the body, but it most commonly appears on the skin as a new mole or a change in an existing mole. Other signs of melanoma may include a mole that is asymmetrical, has irregular borders, is a different color than the surrounding skin, is larger than a pencil eraser, or has a raised or scaly surface. Melanoma can also occur in the eye, mouth, and other parts of the body, and it is important to see a doctor if you have any concerning changes in your skin or other parts of your body.
Pigmentation disorders are medical conditions that affect the production or distribution of melanin, the pigment that gives color to the skin, hair, and eyes. These disorders can cause changes in the color, texture, and appearance of the skin, hair, and eyes, and can range from mild to severe. There are several types of pigmentation disorders, including: 1. Hyperpigmentation: This is an increase in melanin production, which can cause dark spots or patches on the skin. Hyperpigmentation can be caused by a variety of factors, including exposure to the sun, hormonal changes, and certain medications. 2. Hypopigmentation: This is a decrease in melanin production, which can cause light or white patches on the skin. Hypopigmentation can be caused by a variety of factors, including injury to the skin, certain medications, and autoimmune disorders. 3. Melasma: This is a type of hyperpigmentation that typically affects the face and is caused by hormonal changes, such as pregnancy or the use of birth control pills. 4. Vitiligo: This is a type of hypopigmentation that causes white patches on the skin. Vitiligo is caused by the loss of melanocytes, the cells that produce melanin. 5. Albinism: This is a genetic disorder that causes a complete or partial absence of melanin, resulting in white or very light skin, hair, and eyes. Pigmentation disorders can be treated with a variety of methods, including topical creams, laser therapy, and light therapy. In some cases, pigmentation disorders may require medical treatment to manage underlying conditions or to prevent complications.
Albinism, Oculocutaneous (OCA) is a genetic disorder that affects the production of melanin, the pigment that gives color to the skin, hair, and eyes. People with OCA have little or no melanin, which results in light-colored skin, hair, and eyes. There are several types of OCA, each caused by a different genetic mutation. The most common type is OCA1, which is inherited in an autosomal recessive pattern, meaning that a person must inherit two copies of the mutated gene (one from each parent) to develop the condition. OCA can cause a range of symptoms, including sensitivity to light, vision problems, and an increased risk of skin cancer. People with OCA may also have difficulty distinguishing between colors and may have trouble seeing in low light conditions. Treatment for OCA typically involves managing symptoms and providing support for individuals with the condition. This may include wearing protective clothing and sunglasses to shield the skin and eyes from the sun, as well as regular eye exams to monitor for vision problems. In some cases, medication or surgery may be recommended to treat specific symptoms.
Chromatophores are specialized pigment-containing cells found in the skin and scales of many animals, including fish, reptiles, birds, and insects. These cells contain pigments that can be expanded or contracted to change the color and pattern of the skin or scales. In the medical field, chromatophores are often studied in the context of diseases that affect the skin, such as albinism, where there is a deficiency of melanin pigments, and ichthyosis, where there is an abnormal accumulation of keratin in the skin. Chromatophores may also be used in medical treatments, such as photodynamic therapy, where a photosensitizing agent is applied to the skin and activated by light to destroy cancer cells or other abnormal cells. In addition, chromatophores are important in the study of animal behavior and communication. For example, many fish and reptiles use changes in skin color to communicate with other members of their species, and researchers have studied the neural mechanisms underlying these color changes to better understand animal behavior and evolution.
Melanoma, amelanotic is a type of melanoma (a type of skin cancer) that lacks the pigment (melanin) that gives most melanomas their characteristic black or brown color. This type of melanoma is usually pink, red, white, or light brown in color, which can make it more difficult to detect. Amelanotic melanoma is less common than other types of melanoma, but it is more aggressive and tends to spread more quickly to other parts of the body. It is important to have any unusual or changing moles checked by a dermatologist to detect melanoma early, when it is most treatable.
Actinium is a radioactive element that is not commonly used in the medical field. It has a half-life of about 21.8 years and decays primarily through alpha emission, which means it releases high-energy alpha particles. In some medical applications, actinium-225 (225Ac) has been studied as a potential therapeutic agent for cancer treatment. It is a decay product of uranium-233 (233U) and can be produced in a nuclear reactor. 225Ac emits alpha particles that can damage cancer cells and shrink tumors. It has been used in clinical trials for the treatment of various types of cancer, including non-Hodgkin's lymphoma, multiple myeloma, and glioblastoma. However, more research is needed to fully understand the potential benefits and risks of using actinium-225 in medicine.
Levodopa is a medication that is used to treat Parkinson's disease. It is a synthetic form of dopamine, a neurotransmitter that is produced by the brain and is important for controlling movement. Parkinson's disease is a progressive neurological disorder that is characterized by the loss of dopamine-producing cells in the brain, which leads to symptoms such as tremors, stiffness, and difficulty with movement. Levodopa works by being converted into dopamine in the brain, which helps to improve the symptoms of Parkinson's disease. It is usually taken in combination with other medications, such as carbidopa, to increase its effectiveness and reduce side effects.
Alpha-melanocyte-stimulating hormone (α-MSH) is a peptide hormone that is produced by the pituitary gland and the melanocytes (pigment-producing cells) in the skin. It plays a role in regulating the production of melanin, the pigment that gives skin its color, and also has effects on appetite, mood, and the immune system. α-MSH is a 13-amino acid peptide that is derived from the pro-opiomelanocortin (POMC) precursor protein. It is composed of two smaller peptides, α-MSH and β-MSH, which have different functions. α-MSH is the more potent of the two and is primarily responsible for its effects on melanin production and appetite regulation. In the medical field, α-MSH is sometimes used to treat conditions such as vitiligo, a skin disorder characterized by the loss of pigmentation, and anorexia nervosa, an eating disorder characterized by a lack of appetite and a distorted body image. It is also being studied for its potential use in the treatment of other conditions, such as depression and cancer.
In the medical field, "Alternaria" refers to a genus of fungi that can cause a variety of respiratory infections, particularly in people with weakened immune systems. These infections are commonly referred to as "Alternaria lung infections" or "Alternaria asthma." Alternaria fungi are commonly found in soil, water, and plants, and can be inhaled into the lungs when the spores are released into the air. Symptoms of Alternaria lung infections can include coughing, wheezing, shortness of breath, chest tightness, and fever. In severe cases, the infection can cause pneumonia or other serious respiratory complications. Treatment for Alternaria lung infections typically involves antifungal medications, such as fluconazole or itraconazole. In some cases, corticosteroids may also be prescribed to reduce inflammation in the lungs. It is important for people with weakened immune systems to take precautions to avoid exposure to Alternaria fungi, such as wearing a mask when working in dusty environments or avoiding outdoor activities during times when the spores are most prevalent.
Hypothalamic hormones are hormones that are produced by the hypothalamus, a small region of the brain that plays a critical role in regulating various bodily functions, including metabolism, growth, and reproduction. The hypothalamus produces several hormones that are involved in regulating the endocrine system, which is responsible for producing and secreting hormones throughout the body. Some of the most well-known hypothalamic hormones include: 1. Thyrotropin-releasing hormone (TRH): This hormone stimulates the pituitary gland to produce thyroid-stimulating hormone (TSH), which in turn stimulates the thyroid gland to produce thyroid hormones. 2. Corticotropin-releasing hormone (CRH): This hormone stimulates the pituitary gland to produce adrenocorticotropic hormone (ACTH), which in turn stimulates the adrenal gland to produce cortisol. 3. Gonadotropin-releasing hormone (GnRH): This hormone stimulates the pituitary gland to produce follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are involved in regulating the reproductive system. 4. Growth hormone-releasing hormone (GHRH): This hormone stimulates the pituitary gland to produce growth hormone (GH), which is involved in regulating growth and development. 5. Somatostatin: This hormone inhibits the production of several hormones, including GH, TSH, and ACTH. Hypothalamic hormones play a critical role in regulating various bodily functions, and imbalances in these hormones can lead to a range of health problems, including metabolic disorders, reproductive disorders, and endocrine disorders.
Intramolecular oxidoreductases are a class of enzymes that catalyze redox reactions within a single molecule. These enzymes are involved in various biological processes, including metabolism, signal transduction, and gene expression. They typically contain a redox-active site that undergoes changes in oxidation state during the catalytic cycle, allowing them to transfer electrons between different parts of the molecule. Examples of intramolecular oxidoreductases include thioredoxins, glutaredoxins, and peroxiredoxins. These enzymes play important roles in maintaining cellular redox homeostasis and protecting cells against oxidative stress.
Melanin
Melanin Man
Melanin Magic
Melanin theory
Vladimir Melanin
Melanin-concentrating hormone
Melanin-concentrating hormone receptor
Melanin-concentrating hormone receptor 1
Melanin-concentrating hormone receptor 2
Cenococcum geophilum
Cladophialophora bantiana
John McGinness
Rhinocladiella mackenziei
Indole-5,6-quinone
Organic semiconductor
Dopamine
Human hair color
Mary Timms
Fred Martins
L-Dopaquinone
Ciara discography
LaShyra Nolen
Black Female Photographers
Deaths in August 1994
Rhea Boyd
Sophia Danenberg
Florence Margaret Durham
Amelanism
Animal coloration
Frances Cress Welsing
Melanin: MedlinePlus Medical Encyclopedia
Researchers Identify 135 New Melanin Genes Responsible for Pigmentation
Hypothalamus-hippocampus circuitry regulates impulsivity via melanin-concentrating hormone | Nature Communications
Melanin Haircare : Curl Enhancers : Target
Melanin - Glossary Definition
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Which disorder is due to an increase amount of melanin pigment in the skin when there is increased production of melanin by the...
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Melanocytes12
- Melanosomes are found inside melanin-producing pigment cells called melanocytes. (ou.edu)
- Although all humans have the same number of melanocytes, the amount of melanin they produce differs and gives rise to the variation in human skin color. (ou.edu)
- Using CRISPR, we systematically removed more than 20,000 genes from hundreds of millions of melanocytes and observed the impact on melanin production. (ou.edu)
- Using in vitro cell cultures, Bajpai developed a novel method to achieve this goal that detects and quantifies the melanin-producing activity of melanocytes. (ou.edu)
- By passing light through the melanocytes, he could record if the light was either absorbed or scattered by the melanin inside. (ou.edu)
- Deposition of iron within the skin causes inflammation and enhances melanin production by melanocytes. (diagnose-me.com)
- A life-threatening type of skin cancer that occurs in the cells (melanocytes) that produce melanin , the pigment found in skin, hair, and the iris of the eyes. (diagnose-me.com)
- Hair graying results when melanocytes stop producing melanin , the same pigment that darkens our skin to protect us from UV radiation. (diagnose-me.com)
- Which disorder is due to an increase amount of melanin pigment in the skin when there is increased production of melanin by the melanocytes? (xshotpix.com)
- Vitiligo occurs when pigment-producing cells (melanocytes) die or stop producing melanin - the pigment that gives your skin, hair and eyes color. (xshotpix.com)
- General speaking, we can define melanin as a pigment that melanocytes cells produce. (clearessence.com)
- The melanocytes (pigment-producing skin cells) make increased amounts of melanin, a brownish-colored pigment that darkens the skin, resulting in a tan. (msdmanuals.com)
Pigmentation4
- By targeting these new melanin genes, we could also develop melanin-modifying drugs for vitiligo and other pigmentation diseases. (ou.edu)
- Melanin, according to an article from the University of Murcia in Spain, comes from the Greek melanos, meaning dark pigmentation. (clearessence.com)
- Purpose: To show professionals the means to correct the melanin pigmentation of the gingival tissue for aesthetic purposes, highlighting, however, the possibility of recurrence. (bvsalud.org)
- Coloration (pigmentation) is determined by the amount of melanin in the skin. (msdmanuals.com)
Absence of melanin2
- What condition is due to a deficiency or absence of melanin? (xshotpix.com)
- For example, a complete absence of melanin causes a condition called albinism. (xshotpix.com)
Amounts of melanin1
- To understand what actually causes different amounts of melanin to be produced, we used a technology called CRISPR-Cas9 to genetically engineer cells," Bajpai said. (ou.edu)
Synthetic Melanin4
- Amyloid Fibers Increase Free Radicals of Synthetic Melanin. (bvsalud.org)
- Here, we show that adding an amyloid scaffold greatly augments the spin density in synthetic melanin . (bvsalud.org)
- It also brings about concurrent alterations in water dispersibility, bandgaps, and radical scavenging properties of the synthetic melanin , which facilitates its applications in solar water remediation and protection of human keratinocytes from UV irradiation. (bvsalud.org)
- Peptide and protein samples containing varying concentrations of synthetic melanin or fungal pigments extracted from Aspergillus niger were analyzed by MALDI-TOF and MALDI-qTOF (quadrupole TOF) MS. Signal suppression was observed in samples containing greater than 250ng/µl pigment. (cdc.gov)
Lighter-skinned people2
- By understanding what regulates melanin, we can help protect lighter-skinned people from melanoma, or skin cancer," Bajpai said. (ou.edu)
- Darker-skinned people have more melanin than lighter-skinned people and therefore greater built-in protection against the sun's harmful effects. (msdmanuals.com)
Vitiligo1
- There are some diseases that can affect the production of melanin such as albinism and vitiligo, reducing the production of melanin. (clearessence.com)
Synthesis3
- The COMMD3 protein regulated melanin synthesis by controlling the acidity of melanosomes. (ou.edu)
- The addition of tricyclazole to the fungal growth media blocks fungal melanin synthesis and results in less melanized fungi that may be analyzed by MALDI-TOF MS. (cdc.gov)
- However, due to the abnormal pigments' synthesis, being responsible for skin color in accumulation of melanin, the formation of pigment humans. (bvsalud.org)
Fungi2
Humans5
- The skin, hair and eye color of more than eight billion humans is determined by the light-absorbing pigment known as melanin. (ou.edu)
- We identified both new and previously known genes that play important roles in regulating melanin production in humans. (ou.edu)
- The DNA-binding protein KLF6 led to a loss of melanin production in humans and animals, confirming the role KLF6 plays in melanin production in other species as well. (ou.edu)
- As humans moved into areas with less direct sunlight or fewer hours of daylight overall, less melanin was needed. (ou.edu)
- In humans, melanin exists as three forms: eumelanin (which is subdivided further into black and brown forms), pheomelanin, and neuromelanin. (xshotpix.com)
MALDI1
- MALDI qTOF MS mass spectra of the multi-charged peak at m/z 4840 illustrating peak abundance inhibition caused by melanin. (cdc.gov)
Produces2
- Ashley Jones of apparel company Tones of Melanin produces licensed content for HBCUs across the country, and the Sharks are impressed by her enthusiasm and work ethic. (abc.com)
- Overview of Skin Pigment Melanin is the pigment that produces the various shades and colors of human skin, hair, and eyes. (msdmanuals.com)
Accumulation1
- However, in some tissue samples, such as those obtained from the liver, no accumulation of the melanin pigment was observed. (xshotpix.com)
Exposure2
- Sunscreen and sun exposure Sunscreen protects the skin from UV rays, which slow down your melanin production. (xshotpix.com)
- Tanning provides some natural protection against future exposure to UV radiation because melanin absorbs the energy of UV light and helps prevent the light from damaging skin cells and penetrating deeper into the tissues. (msdmanuals.com)
Radiation2
- The first experiment at a brand new laboratory aims to reveal the microscopic mechanisms that allow melanin to protect skin against hazardous UV radiation. (natureasia.com)
- The team at the ASL is also planning to use the laboratory for further tests on melanin, to glean its role in radiation shielding and its magnetic properties, and to study elementary processes in chemical reactions. (natureasia.com)
Genetic Makeup1
- Conclusion: It may be concluded that the pigment returns more rapidly in some subjects, even when the same procedure has been carried by the same operator, because melanin is a pigment that is part of the genetic makeup of individuals with different characteristics. (bvsalud.org)
Darker2
- Dark-skinned individuals produce more melanin, and melanin production increases in response to sunlight, causing the skin to become darker. (diagnose-me.com)
- Darker-skinned persons need 5 to 10 times longer depending on the amount of melanin pigment in the skin. (diagnose-me.com)
Abundance2
- The absence or abundance of the production of melanin can significantly affect an individual's skin. (clearessence.com)
- Melanin inhibits peak abundance. (cdc.gov)
Cells6
- To identify which genes influence melanin production, cells that lost melanin during the gene removal process needed to be separated from millions of other cells that did not. (ou.edu)
- If there are a lot of melanin-producing melanosomes, the light will scatter much more than in cells with little melanin," Bajpai said. (ou.edu)
- Using a process called side-scatter of flow cytometry, we were able to separate cells with more or less melanin. (ou.edu)
- These separated cells were then analyzed to determine the identity of melanin-modifying genes. (ou.edu)
- This effect is due to the depth and density of the pigmented cells (or melanin granule dispersion) and the physical properties of light absorption and reflection described by the Tyndall light phenomenon or effect. (medscape.com)
- However, C. neoformans biofilms were significantly more resistant to amphotericin B and caspofungin than planktonic cells, and their susceptibilities to these drugs were further reduced if cryptococcal cells contained melanin. (who.int)
Melanoma1
- The production of melanin is key for the prevention of skin cancers such as melanoma. (clearessence.com)
Species1
- Tyrosinase plays a central role in catalyzing melanin species (Chang, 2009). (bvsalud.org)
Sunlight1
- Over time, this resulted in melanosomes that produced less melanin, thus absorbing more sunlight. (ou.edu)
Variation1
- In the majority of the cases, this result from the variation of the production of melanin. (clearessence.com)
Production8
- The researchers found 169 functionally diverse genes that impacted melanin production. (ou.edu)
- Gray hair is caused by the gradual reduction of melanin production over time within the affected hair follicle. (diagnose-me.com)
- Melanin Magic, an all-BIPOC production company, performed at the Victoria Event Centre on June 16. (martlet.ca)
- Since Melanin Magic is a production company, they are able to make use of the freedom to select who gets to be invited to perform. (martlet.ca)
- Vitamin A. Studies suggest vitamin A is important to melanin production and is essential to having healthy skin. (xshotpix.com)
- What can stop melanin production? (xshotpix.com)
- However, there are different factors affecting the production of melanin. (clearessence.com)
- This could leading to a difference in the amount of melanin production. (clearessence.com)
Spots2
- Clusters of dark spots on the skin (concentrated melanin ) usually found on people with light skin. (diagnose-me.com)
- Melanin has essential physiological effects, spots can be directly related to aesthetic and emotional problems (Ikino et al . (bvsalud.org)
Tones1
- Additional research on dark skin tones is required to further understand how melanin concentration affects PPG technology. (wku.edu)
Shades1
- Due to inheritance, different ethnicity are genetically predispose to produce different shades of melanin. (clearessence.com)
Diseases2
- Researchers could develop effective interventions against these microbes and their diseases by discovering and targeting such melanin-producing genes. (ou.edu)
- A deficiency in melanin can lead to several disorders and diseases. (xshotpix.com)
Color4
- Check out Sacramento Pipeworks member Gabriel Patterson's feature " Growing Up Black and Outdoorsy " on Melanin Base Camp , a social media collective working to increase the visibility of adventurers of color. (touchstoneclimbing.com)
- Our rich, illuminating True Melanin Eyeshadow Palette effortlessly accentuates your natural glow with color combos that are as bold as they are bright. (blackopalbeauty.com)
- Melanin is brown, yet it imparts a blue, green, or brown color to the eye. (medscape.com)
- Melanin is the pigment that gives skin its color. (cdc.gov)
Tissue1
- The melanin pigment was present in all of the tissue layers of most organs, while the melanin pigment was found in only specific layers of some of the organs. (xshotpix.com)
Researchers1
- Researchers at King Saud University in Riyadh will use attosecond laser technology to take a closer look at melanin and how it works. (natureasia.com)
Produce3
- Required to produce melanin and to synthesize fatty acids. (diagnose-me.com)
- What vitamin helps produce melanin? (xshotpix.com)
- People who are exposed more to the sun produce more melanin as a result. (clearessence.com)
Light1
- This technology is used in fitness tracking devices to estimate heart rate (HR). There is little research on how PPG technology is affected by skin tone, despite the possibility that skin with more melanin may not reflect light as well as lighter skin. (wku.edu)
Natural1
- This work provides implications in the unrevealed role of functional amyloid in melanogenesis and in the origin of the superiority of natural melanin toward its synthetic variants in terms of the spin-related properties. (bvsalud.org)
Found1
- Melanin Magic can be found at Diosa De La Luna Entertainment on Instagram, Facebook, as well as their website . (martlet.ca)
Relate1
- In particular, melanin-based traits are known to relate to condition and there is a well-characterized genetic pathway underpinning their expression. (ifremer.fr)
Protect the skin2
- Melanin also helps protect the skin from the sun. (medlineplus.gov)
- Melanin is produced to protect the skin from the UV rays. (clearessence.com)
Role1
- Electrons in the melanin molecule have to play a fundamental role in these mechanisms. (natureasia.com)
Types1
- What are the 3 types of melanin? (xshotpix.com)
Make1
- A palette to make your melanin pop! (blackopalbeauty.com)
Important1
- Fpor me it's really important to say you are enough," said Cheeks about Melanin Magic and burlesque. (martlet.ca)
Essential1
- Melanin , the normal body pigment, is synthesized from the essential amino acid L-phenylalanine by an enzyme system dependent on copper, vitamin B6, vitamin C. (diagnose-me.com)
Creating a safe space1
- And for Melanin Magic, that focus is on creating a safe space for their performers to explore themselves. (martlet.ca)
Energy1
- The short UV pulses generated by femtosecond and asttosecond lasers should help us to unravel some of the details of these mysterious non-destructive melanin high-energy photon interactions, and it may suggest methods for protection against nuclear radiations using an organic material," adds Haseeb. (natureasia.com)
Effects1
- The purpose of this study was to investigate the effects of melanin concentration in skin on the HR measurement accuracy of the Apple Watch Series 6, FitBit Versa 3, MI Band, Fitbit Inspire 2, Letsfit Smartwatch, and Garmin Vivo 4 in treadmill walking, and activities of daily living (climbing stairs, vacuuming, picking up toys, and carrying groceries). (wku.edu)