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McCune–Albright Syndrome
McCune–Albright syndrome is a complex genetic disorder affecting the bone, skin and endocrine systems. It is a mosaic disease arising from somatic activating mutations in '' GNAS'', which encodes the alpha-subunit of the Gs heterotrimeric G protein. It was first described in 1937 by American pediatrician Donovan James McCune and American endocrinologist Fuller Albright. Signs and symptoms McCune–Albright syndrome is suspected when two or more of the following features are present: * Fibrous dysplasia * Hyperpigmented skin lesions with characteristic features, including jagged "coast of Maine" borders and tendency occur along the midline of the body. These lesions are historically termed café au lait macules, however the term "cafe-au-lait" only describes their appearance on lighter-skinned individuals. * Hyperfunctioning endocrine disease Patients may have one or many of these features, which may occur in any combination. As such, the clinical presentation of patients w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lines Of Blaschko
Blaschko's lines, also called the lines of Blaschko, are lines of normal cell development in the skin. These lines are only visible in those with a Mosaic (genetics), mosaic skin condition or in Chimera (genetics), chimeras where different cell lines contain different genes. These lines may express different amounts of melanin, or become visible due to a differing susceptibility to disease. In such individuals, they can become apparent as whorls, patches, streaks or lines in a linear or segmental distribution over the skin. They follow a ''V'' shape over the back, ''S''-shaped whirls over the chest and sides, and wavy shapes on the head. Not all mosaic skin conditions follow Blascko's lines. The lines are believed to trace the migration of embryonic cells. They do not correspond to nervous system, nervous, muscular system, muscular, or lymphatic system, lymphatic systems. The lines are not unique to humans and can be observed in other non-human animals with mosaicism. Alfred Bl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postzygotic Mutation
A postzygotic mutation (or post-zygotic mutation) is a change in an organism's genome that is acquired during its lifespan, instead of being inherited from its parent(s) through fusion of two haploid gametes. Mutations that occur after the zygote has formed can be caused by a variety of sources that fall under two classes: spontaneous mutations and induced mutations. How detrimental a mutation is to an organism is dependent on what the mutation is, where it occurred in the genome and when it occurred. Causes Postzygotic changes to a genome can be caused by small mutations that affect a single base pair, or large mutations that affect entire chromosomes and are divided into two classes, spontaneous mutations and induced mutations. Spontaneous Mutations Most spontaneous mutations are the result of naturally occurring lesions to DNA and errors during DNA replication without direct exposure to an agent. A few common spontaneous mutations are: * Depurination- The loss of a purin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioamide
A thioamide (rarely, thionamide, but also known as thiourylenes) is a functional group with the general structure R–CS–NR′R″, where R, R′, and R″ are organic groups. They are analogous to amides but they exhibit greater multiple bond character along the C-N bond, resulting in a larger rotational barrier. One of the best-known thioamides is thioacetamide, which is used as a source of the sulfide ion and is a building block in heterocyclic chemistry. Thioamides or anti-thyroid drugs are also a class of drugs that are used to control thyrotoxicosis. Preparation and structure Thioamides are typically prepared by treating amides with phosphorus sulfides such as phosphorus pentasulfide, a reaction first described in the 1870s. Alternative routes include the use of Lawesson's reagent or the reaction of nitriles with hydrogen sulfide: The Willgerodt-Kindler reaction also affords benzylthioamides. The C2NH2S core of thioamides is planar. Using thioacetamide as represent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flutamide
Flutamide, sold under the brand name Eulexin among others, is a nonsteroidal antiandrogen (NSAA) which is used primarily to treat prostate cancer. It is also used in the treatment of androgen-dependent conditions like acne, excessive hair growth, and high androgen levels in women. It is taken by mouth, usually three times per day. Side effects in men include breast tenderness and enlargement, feminization, sexual dysfunction, and hot flashes. Conversely, the medication has fewer side effects and is better-tolerated in women with the most common side effect being dry skin. Diarrhea and elevated liver enzymes can occur in both sexes. Rarely, flutamide can cause liver damage, lung disease, sensitivity to light, elevated methemoglobin, elevated sulfhemoglobin, and deficient neutrophils. Numerous cases of liver failure and death have been reported, which has limited the use of flutamide. Flutamide acts as a selective antagonist of the androgen receptor (AR), competing wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spironolactone
Spironolactone, sold under the brand name Aldactone among others, is a medication that is primarily used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It is also used in the treatment of high blood pressure, low blood potassium that does not improve with supplementation, early puberty in boys, acne and excessive hair growth in women, and as a part of transgender hormone therapy in transfeminine people. Spironolactone is taken by mouth. Common side effects include electrolyte abnormalities, particularly high blood potassium, nausea, vomiting, headache, rashes, and a decreased desire for sex. In those with liver or kidney problems, extra care should be taken. Spironolactone has not been well studied in pregnancy and should not be used to treat high blood pressure of pregnancy. It is a steroid that blocks the effects of the hormones aldosterone and testosterone and has some estrogen-like effects. Spironolactone belongs to a class of medicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Letrozole
Letrozole, sold under the brand name Femara among others, is an aromatase inhibitor medication that is used in the treatment of breast cancer. It was patented in 1986 and approved for medical use in 1996. In 2020, it was the 257th most commonly prescribed medication in the United States, with more than 1million prescriptions. Medical uses Breast cancer Letrozole is approved by the United States Food and Drug Administration (FDA) for the treatment of local or metastatic breast cancer that is hormone receptor positive or has an unknown receptor status in postmenopausal women.Drugs.com: for letrozole. It is also used for ovarian cancer patients after they have completed chemotherapy. Comparison with tamoxifen Tamoxifen is also used to treat hormonally-responsive breast cancer, but it does so by interfering with the estrogen receptor. However, letrozole is effective only in post-menopausal women, in whom estrogen is produced predominantly in peripheral tissues (i.e. in adip ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denosumab
Denosumab (trade names Prolia and Xgeva) is a human monoclonal antibody for the treatment of osteoporosis, treatment-induced bone loss, metastases to bone, and giant cell tumor of bone. Denosumab is contraindicated in people with low blood calcium levels. The most common side effects are joint and muscle pain in the arms or legs. Denosumab is a inhibitor of RANKL (receptor activator of nuclear factor kappa-Β ligand), which works by preventing the development of osteoclasts, which are cells that break down bone. It was developed by the biotechnology company Amgen. Medical uses Denosumab is used for those with osteoporosis at high risk for fractures, bone loss due to certain medications, and in those with bone metastases. Cancer A 2012 meta-analysis found that denosumab was better than placebo, zoledronic acid and pamidronate, in reducing the risk of fractures in those with cancer. Osteoporosis In those with postmenopausal osteoporosis denosumab decreases the risk of fracture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bisphosphonates
Bisphosphonates are a class of drugs that prevent the loss of bone density, used to treat osteoporosis and similar diseases. They are the most commonly prescribed drugs used to treat osteoporosis. They are called bisphosphonates because they have two phosphonate () groups. They are thus also called diphosphonates ('' bis-'' or '' di-'' + ''phosphonate''). Evidence shows that they reduce the risk of fracture in post-menopausal women with osteoporosis. Bone tissue undergoes constant remodeling and is kept in balance (homeostasis) by osteoblasts creating bone and osteoclasts destroying bone. Bisphosphonates inhibit the digestion of bone by encouraging osteoclasts to undergo apoptosis, or cell death, thereby slowing bone loss. The uses of bisphosphonates include the prevention and treatment of osteoporosis, Paget's disease of bone, bone metastasis (with or without hypercalcemia), multiple myeloma, primary hyperparathyroidism, osteogenesis imperfecta, fibrous dysplasia, and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scoliosis
Scoliosis is a condition in which a person's spine has a sideways curve. The curve is usually "S"- or "C"-shaped over three dimensions. In some, the degree of curve is stable, while in others, it increases over time. Mild scoliosis does not typically cause problems, but more severe cases can affect breathing and movement. Pain is usually present in adults, and can worsen with age. The cause of most cases is unknown, but it is believed to involve a combination of genetic and environmental factors. Risk factors include other affected family members. It can also occur due to another condition such as muscle spasms, cerebral palsy, Marfan syndrome, and tumors such as neurofibromatosis. Diagnosis is confirmed with X-rays. Scoliosis is typically classified as either structural in which the curve is fixed, or functional in which the underlying spine is normal. Treatment depends on the degree of curve, location, and cause. Minor curves may simply be watched periodically. Treatme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CT Scan
A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists. CT scanners use a rotating X-ray tube and a row of detectors placed in a gantry (medical), gantry to measure X-ray Attenuation#Radiography, attenuations by different tissues inside the body. The multiple X-ray measurements taken from different angles are then processed on a computer using tomographic reconstruction algorithms to produce Tomography, tomographic (cross-sectional) images (virtual "slices") of a body. CT scans can be used in patients with metallic implants or pacemakers, for whom magnetic resonance imaging (MRI) is Contraindication, contraindicated. Since its development in the 1970s, CT scanning has proven to be a versatile imaging technique. While CT is most prominently used in medical diagnosis, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Adenosine Monophosphate
Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is a derivative of adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway. History Earl Sutherland of Vanderbilt University won a Nobel Prize in Physiology or Medicine in 1971 "for his discoveries concerning the mechanisms of the action of hormones", especially epinephrine, via second messengers (such as cyclic adenosine monophosphate, cyclic AMP). Synthesis Cyclic adenosine monophosphate, AMP is synthesized from Adenosine triphosphate, ATP by adenylate cyclase located on the inner side of the plasma membrane and anchored at various locations in the interior of the cell. Adenylate cyclase is ''activated'' by a range of signaling molecules through the activation of adenylate cyclase stimulatory G (Gs alpha subunit, Gs)-protein-coupled recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosaicism
Mosaicism or genetic mosaicism is a condition in multicellular organisms in which a single organism possesses more than one genetic line as the result of genetic mutation. This means that various genetic lines resulted from a single fertilized egg. Genetic mosaics may often be confused with chimerism, in which two or more genotypes arise in one individual similarly to mosaicism. In chimerism, though, the two genotypes arise from the fusion of more than one fertilized zygote in the early stages of embryonic development, rather than from a mutation or chromosome loss. Genetic mosaicism can result from many different mechanisms including chromosome nondisjunction, anaphase lag, and endoreplication. Anaphase lagging is the most common way by which mosaicism arises in the preimplantation embryo. Mosaicism can also result from a mutation in one cell during development, in which case the mutation will be passed on only to its daughter cells (and will be present only in certain adult cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
