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Tumor Progression
Tumor progression is the third and last phase in tumor development. This phase is characterised by increased growth speed and invasiveness of the tumor cells. As a result of the progression, phenotypical changes occur and the tumor becomes more aggressive and acquires greater malignant potential. Together with the progression, more and more aneuploidy occurs. This may be evident as nuclear polymorphism. See also * Tumor initiation * Tumor promotion Tumor promotion is a process in carcinogenesis by which various factors permit the descendants of a single initiated cell to survive and expand in number, i.e. to resist apoptosis and to undergo clonal growth. This is a step toward tumor progressi ... References External links Progressionentry in the public domain NCI Dictionary of Cancer Terms Carcinogenesis {{Oncology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRI Slices - 2007 And 2014 Of Astrocytoma Patient - Steven Keating
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from CT and PET scans. MRI is a medical application of nuclear magnetic resonance (NMR) which can also be used for imaging in other NMR applications, such as NMR spectroscopy. MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of disease. Compared to CT, MRI provides better contrast in images of soft-tissues, e.g. in the brain or abdomen. However, it may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, though "Open" MRI designs mostly relieve this. Additionally, implants and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, poten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aneuploidy
Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46. It does not include a difference of one or more complete sets of chromosomes. A cell with any number of complete chromosome sets is called a ''euploid'' cell. An extra or missing chromosome is a common cause of some genetic disorders. Some cancer cells also have abnormal numbers of chromosomes. About 68% of human solid tumors are aneuploid. Aneuploidy originates during cell division when the chromosomes do not separate properly between the two cells ( nondisjunction). Most cases of aneuploidy in the autosomes result in miscarriage, and the most common extra autosomal chromosomes among live births are 21, 18 and 13. Chromosome abnormalities are detected in 1 of 160 live human births. Autosomal aneuploidy is more dangerous than sex chromosome aneuploidy, as autosomal aneuploidy is almost always lethal to embryos that cease dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Initiation
Tumor initiation is defined as "a process in which normal cells are changed so that they are able to form tumors". It is the first phase in tumor development. Mutagens, substances that cause cancer can be tumor initiators. See also * Tumor promotion Tumor promotion is a process in carcinogenesis by which various factors permit the descendants of a single initiated cell to survive and expand in number, i.e. to resist apoptosis and to undergo clonal growth. This is a step toward tumor progressi ... * Tumor progression References Carcinogenesis {{Oncology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumor Promotion
Tumor promotion is a process in carcinogenesis by which various factors permit the descendants of a single initiated cell to survive and expand in number, i.e. to resist apoptosis and to undergo clonal growth. This is a step toward tumor progression. In order for a tumor cell to survive, it must decrease its expression of tumor suppressor genes such as p53, BRCA1, BRCA2, RB1, or the fas receptor. A tumor suppressor would trigger an apoptotic pathway in a cancer cell if there were DNA damage, polyploidy, or uncontrolled cell growth. Simultaneously, tumor cells need to upregulate oncogenes, which promote or cause downstream activation of growth factors and cell survival signals such as RAS, Mitogen-activated protein kinase kinase, VEGF, or Akt. See also * Phorbol myristate acetate * Tumor initiation * Tumor progression Tumor progression is the third and last phase in tumor development. This phase is characterised by increased growth speed and invasiveness of the tumor cells. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
