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Retinoblastoma
Retinoblastoma (Rb) is a rare form of cancer that rapidly develops from the immature cells of a retina, the light-detecting tissue of the eye. It is the most common primary malignant intraocular cancer in children, and it is almost exclusively found in young children. Though most children survive this cancer, they may lose their vision in the affected eye(s) or need to have the eye removed. Almost half of children with retinoblastoma have a hereditary genetic defect associated with retinoblastoma. In other cases, it is caused by a congenital mutation in the chromosome 13 gene 13q14 (retinoblastoma protein). Signs and symptoms Retinoblastoma is universally known as the most intrusive intraocular cancer among children. The chance of survival and preservation of the eye depends fully on the severity. Retinoblastoma is extremely rare as there are only about 200 to 300 cases every year in the United States. Looking at retinoblastoma globally, only 1 in about 15,000 children have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinoblastoma Protein
The retinoblastoma protein (protein name abbreviated pRb; gene name abbreviated ''Rb'', ''RB'' or ''RB1'') is a proto-oncogenic tumor suppressor protein that is dysfunctional in several major cancers. One function of pRb is to prevent excessive cell growth by inhibiting cell cycle progression until a cell is ready to divide. When the cell is ready to divide, pRb is phosphorylated, inactivating it, and the cell cycle is allowed to progress. It is also a recruiter of several chromatin remodeling enzymes such as methylases and acetylases. pRb belongs to the pocket protein family, whose members have a pocket for the functional binding of other proteins. Should an oncogenic protein, such as those produced by cells infected by high-risk types of human papillomavirus, bind and inactivate pRb, this can lead to cancer. The ''RB'' gene may have been responsible for the evolution of multicellularity in several lineages of life including animals. Name and genetics In humans, the prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Suppressor Gene
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or reduction in its function. In combination with other genetic mutations, this could allow the cell to grow abnormally. The loss of function for these genes may be even more significant in the development of human cancers, compared to the activation of oncogenes. TSGs can be grouped into the following categories: caretaker genes, gatekeeper genes, and more recently landscaper genes. Caretaker genes ensure stability of the genome via DNA repair and subsequently when mutated allow mutations to accumulate. Meanwhile, gatekeeper genes directly regulate cell growth by either inhibiting cell cycle progression or inducing apoptosis. Lastly landscaper genes regulate growth by contributing to the surrounding environment, when mutated can cause an envir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinealoblastoma
Pineoblastoma is a malignant tumor of the pineal gland. A pineoblastoma is a supratentorial midline primitive neuroectodermal tumor. Pineoblastoma can present at any age, but is most common in young children. They account for 0.001% of all primary CNS neoplasms. Epidemiology Pineoblastomas typically occur at very young ages. One study found the average age of presentation to be 4.3 years, with peaks at age 3 and 8. Another cites cases to more commonly occur in patients under 2 years of age. Rates of occurrence for males and females are similar, but may be slightly more common in females. One study found incidence of pineoblastoma to be increased in black patients compared to white patients by around 71%. This difference was most apparent in patients aged 5 to 9 years old. Pathophysiology The pineal gland is a small organ in the center of the brain that is responsible for controlling melatonin secretion. Several tumors can occur in the area of the pineal gland, with the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilateral Retinoblastoma
Trilateral retinoblastoma is a malignant midline primitive neuroectodermal tumor occurring in patients with inherited uni- or bilateral retinoblastoma. In most cases trilateral retinoblastoma presents itself as pineoblastoma (pineal TRb). In about a fourth of the cases the tumor develops in another intracranial region, most commonly supra- or parasellar (non-pineal TRb), but there are reported cases with non-pineal TRb in the 3rd ventricle. In most cases pineal TRb is diagnosed before the age of 5, but after the diagnosis of retinoblastoma. Non-pineal TRb, however, is often diagnosed simultaneous with retinoblastoma. Prognosis of patients with trilateral retinoblastoma is dismal, only a few patients have survived more than 5 years after diagnosis; all survivors were diagnosed with small tumors in a subclinical stage. Recent advances in (high-dose) chemotherapy treatment regimens and early detection have improved survival of patients with trilateral retinoblastoma. See also * Primi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Knudson Hypothesis
The Knudson hypothesis, also known as the two-hit hypothesis, is the hypothesis that most tumor suppressor genes require both alleles to be inactivated, either through mutations or through epigenetic silencing, to cause a phenotypic change. It was first formulated by Alfred G. Knudson in 1971 and led indirectly to the identification of tumor suppressor genes. Knudson won the 1998 Albert Lasker Clinical Medical Research Award for this work. Knudson performed a statistical analysis on cases of retinoblastoma, a tumor of the retina that occurs both as an inherited disease and sporadically. He noted that inherited retinoblastoma occurs at a younger age than the sporadic disease. In addition, the children with inherited retinoblastoma often developed the tumor in both eyes, suggesting an underlying predisposition. Knudson suggested that two "hits" to DNA were necessary to cause the cancer. In the children with inherited retinoblastoma, the first mutation in what later came to be identi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukocoria
Leukocoria (also white pupillary reflex) is an abnormal white reflection from the retina of the eye. Leukocoria resembles eyeshine, but leukocoria can also occur in animals that lack eyeshine because their retina lacks a ''tapetum lucidum''. Leukocoria is a medical sign for a number of conditions, including Coats disease, congenital cataract, corneal scarring, melanoma of the ciliary body, Norrie disease, ocular toxocariasis, persistence of the tunica vasculosa lentis (PFV/PHPV), retinoblastoma, and retrolental fibroplasia. Because of the potentially life-threatening nature of retinoblastoma, a cancer, that condition is usually considered in the evaluation of leukocoria. In some rare cases (1%) the leukocoria is caused by Coats' disease (leaking retinal vessels). Diagnosis On photographs taken using a flash, instead of the familiar red-eye effect, leukocoria can cause a bright white reflection in an affected eye. Leukocoria may appear also in low indirect light, similar to eyes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukocoria
Leukocoria (also white pupillary reflex) is an abnormal white reflection from the retina of the eye. Leukocoria resembles eyeshine, but leukocoria can also occur in animals that lack eyeshine because their retina lacks a ''tapetum lucidum''. Leukocoria is a medical sign for a number of conditions, including Coats disease, congenital cataract, corneal scarring, melanoma of the ciliary body, Norrie disease, ocular toxocariasis, persistence of the tunica vasculosa lentis (PFV/PHPV), retinoblastoma, and retrolental fibroplasia. Because of the potentially life-threatening nature of retinoblastoma, a cancer, that condition is usually considered in the evaluation of leukocoria. In some rare cases (1%) the leukocoria is caused by Coats' disease (leaking retinal vessels). Diagnosis On photographs taken using a flash, instead of the familiar red-eye effect, leukocoria can cause a bright white reflection in an affected eye. Leukocoria may appear also in low indirect light, similar to eyes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 13 (human)
Chromosome 13 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 13 spans about 114 million base pairs (the building material of DNA) and represents between 3.5 and 4% of the total DNA in cells. Genes Number of genes The following are some of the gene count estimates of human chromosome 13. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project ( CCDS) takes an extremely conservative strategy. So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes. Gene list The following is a partial list of genes on human chromosome 13. For complete list, see the link in the infobox on the right. Diseases and disorders The following diseases and disorders are some of those rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 13
Chromosome 13 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 13 spans about 114 million base pairs (the building material of DNA) and represents between 3.5 and 4% of the total DNA in cells. Genes Number of genes The following are some of the gene count estimates of human chromosome 13. Because researchers use different approaches to genome annotation their predictions of the number of genes on each chromosome varies (for technical details, see gene prediction). Among various projects, the collaborative consensus coding sequence project ( CCDS) takes an extremely conservative strategy. So CCDS's gene number prediction represents a lower bound on the total number of human protein-coding genes. Gene list The following is a partial list of genes on human chromosome 13. For complete list, see the link in the infobox on the right. Diseases and disorders The following diseases and disorders are some of those rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red-eye Effect
The red-eye effect in photography is the common appearance of red pupils in color photographs of the eyes of humans and several other animals. It occurs when using a photographic flash that is very close to the camera lens (as with most compact cameras) in ambient low light. Causes In flash photography the light of the flash occurs too fast for the pupil to close, so much of the very bright light from the flash passes into the eye through the pupil, reflects off the fundus at the back of the eyeball and out through the pupil. The camera records this reflected light. The main cause of the red color is the ample amount of blood in the choroid which nourishes the back of the eye and is behind the retina. The blood in the retinal circulation is far less than in the choroid, and plays virtually no role. The eye contains several photostable pigments that all absorb in the short wavelength region, and hence contribute somewhat to the red eye effect. The lens cuts off deep blue and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rb Whiteeye
Rb or RB may stand for: Arts and entertainment * Rebecca Black, an American pop singer * Richard Blackwood, a British rapper * Rhythm and blues, a music genre combining blues, gospel and jazz influences * ''Rock Band'', a music video game series * ''Rock Band'' (video game), the game of the same name *''Ultraman R/B'', a Japanese television series Businesses * Rankin/Bass, an American production company, known for its seasonal television specials * Ray-Ban, a sunglasses company * Reckitt Benckiser, a company in the United Kingdom * Syrian Arab Airlines (IATA airline code RB) Government and politics * Radio Bremen, a public broadcaster for the German state of Bremen * ''Parti de la Renaissance du Bénin'' or Benin Rebirth Party, a political party in Benin * República Bolivariana, Spanish-language phrase for the type of government in Venezuela * Rupiah Banda, President of Zambia Science and technology * .rb, the file extension for documents created in Ruby or in REAL Basic * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enucleation Of The Eye
Enucleation is the removal of the eye that leaves the eye muscles and remaining orbital contents intact. This type of ocular surgery is indicated for a number of ocular tumors, in eyes that have sustained severe trauma, and in eyes that are otherwise blind and painful. Self-enucleation or auto-enucleation (oedipism) and other forms of serious self-inflicted eye injury are an extremely rare form of severe self-harm that usually results from mental illnesses involving acute psychosis. The name comes from Oedipus of Greek mythology, who gouged out his own eyes. Classification There are three types of eye removal: * Evisceration – removal of the iris, cornea, and internal eye contents, but with the sclera and attached extraocular muscles left behind * Enucleation of the eye - removal of the eyeball, but with the eyelids and adjacent structures of the eye socket remaining. An intraocular tumor excision requires an enucleation, not an evisceration. * Exenteration – removal of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
