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Embryonal Tumour With Multilayered Rosettes
Embryonal tumor with multilayered rosettes (ETMR) is an embryonal central nervous system tumor. It is considered an embryonal tumor because it arises from cells partially differentiated or still undifferentiated from birth, usually neuroepithelial cells, stem cells destined to turn into glia or neurons. It can occur anywhere within the brain and can have multiple sites of origins, with a high probability of metastasis through cerebrospinal fluid (CSF). Metastases outside the central nervous system have been reported, but remain rare. Until recently, ETMRs were not recognized as a standalone entity and were grouped together with other CNS primitive neuroectodermal tumors. Histologically, it is similar to other CNS embryonal tumors, such as medulloblastoma, but different regarding genetic factors. It is a rare disease occurring in less than 1 in 700,000 children under the age of 4. Symptoms depend on the location of the tumor and, thus, may vary, but they may include raised in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Life Expectancy
Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, current age, and other demographic factors like sex. The most commonly used measure is life expectancy at birth (LEB), which can be defined in two ways. ''Cohort'' LEB is the mean length of life of a birth cohort (all individuals born in a given year) and can be computed only for cohorts born so long ago that all their members have died. ''Period'' LEB is the mean length of life of a hypothetical cohort assumed to be exposed, from birth through death, to the mortality rates observed at a given year. National LEB figures reported by national agencies and international organizations for human populations are estimates of ''period'' LEB. In the Bronze Age and the Iron Age, human LEB was 26 years; in 2010, world LEB was 67.2 years. In recent years, LEB in Eswatini (formerly Swaziland) is 49, while LEB in Japan is 83. The combination of high infant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebrospinal Fluid
Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the brain, and absorbed in the arachnoid granulations. There is about 125 mL of CSF at any one time, and about 500 mL is generated every day. CSF acts as a shock absorber, cushion or buffer, providing basic mechanical and immunological protection to the brain inside the skull. CSF also serves a vital function in the cerebral autoregulation of cerebral blood flow. CSF occupies the subarachnoid space (between the arachnoid mater and the pia mater) and the ventricular system around and inside the brain and spinal cord. It fills the ventricles of the brain, cisterns, and sulci, as well as the central canal of the spinal cord. There is also a connection from the subarachnoid space to the bony labyrinth of the inner ear via the per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicer
Dicer, also known as endoribonuclease Dicer or helicase with RNase motif, is an enzyme that in humans is encoded by the gene. Being part of the RNase III family, Dicer cleaves double-stranded RNA (dsRNA) and pre-microRNA (pre-miRNA) into short double-stranded RNA fragments called small interfering RNA and microRNA, respectively. These fragments are approximately 20–25 base pairs long with a two-base overhang on the 3′-end. Dicer facilitates the activation of the RNA-induced silencing complex (RISC), which is essential for RNA interference. RISC has a catalytic component Argonaute, which is an endonuclease capable of degrading messenger RNA (mRNA). Discovery Dicer was given its name in 2001 by Stony Brook PhD student Emily Bernstein while conducting research in Gregory Hannon's lab at Cold Spring Harbor Laboratory. Bernstein sought to discover the enzyme responsible for generating small RNA fragments from double-stranded RNA. Dicer's ability to generate around ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIN28A (gene)
Lin-28 homolog A is a protein that in humans is encoded by the ''LIN28'' gene. LIN28 encodes an RNA-binding protein that binds to and enhances the translation of the IGF-2 (insulin-like growth factor 2) mRNA. Lin28 binds to the let-7 pre-microRNA and blocks production of the mature let-7 microRNA in mouse embryonic stem cells. In pluripotent embryonal carcinoma cells, LIN28 is localized in the ribosomes, P-bodies and stress granules. Function Stem cell expression LIN28 is thought to regulate the self-renewal of stem cells. In ''Caenorhabditis elegans'', there is only one Lin28 gene that is expressed and in vertebrates, there are two paralogs present, Lin28a and Lin28b. In nematodes, the LIN28 homolog lin-28 is a heterochronic gene that determines the onset of early larval stages of developmental events in ''C. elegans'', by regulating the self-renewal of nematode stem cells in the skin (called seam cells) and vulva (called VPCs) during development. In mice, LIN28 is highl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C19MC MiRNA Cluster
The C19MC miRNA cluster is a microRNA cluster consisting of 46 genes. These 46 genes encode 59 mature miRNAs. The C19MC miRNA cluster is only found in primate (including human) genomes and expresses miRNAs almost exclusively in the placenta, but also in testis, embryonic stem cells, and some tumors. They are also expressed highly in trophoblast-derived vesicles, including exosomes. C19MC miRNAs have been shown to be among the most expressed miRNAs in the human placenta and are also found in the serum of pregnant women. Trophoblast cells, found in the human placenta, produce many different types of microRNAs (miRNAs). MicroRNAs play a role in placental development or physiology. Some placental cell lines derived from trophoblasts also express C19MC miRNA, including the choriocarcinoma Choriocarcinoma is a malignant, trophoblastic cancer, usually of the placenta. It is characterized by early hematogenous spread to the lungs. It belongs to the malignant end of the spectrum in gest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ependymoblastoma
Primitive neuroectodermal tumor is a malignant (cancerous) neural crest tumor. It is a rare tumor, usually occurring in children and young adults under 25 years of age. The overall 5 year survival rate is about 53%. It gets its name because the majority of the cells in the tumor are derived from neuroectoderm, but have not developed and differentiated in the way a normal neuron would, and so the cells appear "primitive".PNET belongs to the Ewing family of tumors. Genetics Using gene transfer of SV40 large T-antigen in neuronal precursor cells of rats, a brain tumor model was established. The PNETs were histologically indistinguishable from the human counterparts and have been used to identify new genes involved in human brain tumor carcinogenesis. The model was used to confirm p53 as one of the genes involved in human medulloblastomas, but since only about 10% of the human tumors showed mutations in that gene, the model can be used to identify the other binding partners of SV40 L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medulloepithelioma
Medulloepithelioma is a rare, primitive, fast-growing brain tumour thought to stem from cells of the embryonic medullary cavity.Definition of Medulloepithelioma , from Online Medical Dictionary. Retrieved 7 January 2010. Tumours originating in the of the are referred to as embryonal medulloepitheliomas, or s.McGraw-Hill Concise Dic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WHO Classification Of Tumours Of The Central Nervous System
The following is a simplified (deprecated) version of the 2021 WHO classification of the tumours of the central nervous system. Currently, as of 2021, clinicians are using the WHO grade 5th edition, which incorporates recent advances in molecular pathology. Listed for each tumour are the WHO official name, the ICD-O code (with Arabic numeral, where /0 indicates "benign" tumour, /3 malignant tumour and /1 borderline tumour), and the WHO Grade (a parameter connected with the "aggressiveness" of the tumour), also in Arabic numerals as per the updated 2021 guidelines.See the article Grading of the tumors of the central nervous system. 1. Gliomas, glioneuronal tumors, and neuronal tumours :1.1 Adult-type diffuse gliomas ::1.1.1 Astrocytoma, IDH-mutant ::1.1.2 Oligodendroglioma, IDH-mutant, and 1p/19q-codeleted ::1.1.3 Glioblastoma, IDH-wildtype :1.2 Pediatric-type diffuse low-grade gliomas ::1.2.1 Diffuse astrocytoma, MYB- or MYBL1-altered ::1.2.2 Angiocentric glioma ::1.2.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation Therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is called radiation oncology. A physician who practices in this subspecialty is a radiation oncologist. Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of cancerous tis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medulloblastoma
Medulloblastoma is a common type of primary brain cancer in children. It originates in the part of the brain that is towards the back and the bottom, on the floor of the skull, in the cerebellum, or posterior fossa. The brain is divided into two main parts, the larger cerebrum on top and the smaller cerebellum below towards the back. They are separated by a membrane called the tentorium. Tumors that originate in the cerebellum or the surrounding region below the tentorium are, therefore, called infratentorial. Historically medulloblastomas have been classified as a primitive neuroectodermal tumor (PNET), but it is now known that medulloblastoma is distinct from supratentorial PNETs and they are no longer considered similar entities. Medulloblastomas are invasive, rapidly growing tumors that, unlike most brain tumors, spread through the cerebrospinal fluid and frequently metastasize to different locations along the surface of the brain and spinal cord. Metastasis all the way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System Primitive Neuroectodermal Tumor
A central nervous system primitive neuroectodermal tumor, often abbreviated as PNET, supratentorial PNET, or CNS-PNET, is one of the 3 types of embryonal central nervous system tumors defined by the World Health Organization (medulloblastoma, atypical teratoid rhabdoid tumor, and PNET). It is considered an embryonal tumor because it arises from cells partially differentiated or still undifferentiated from birth. Those cells are usually neuroepithelial cells, stem cells destined to turn into glia or neurons. It can occur anywhere within the spinal cord and cerebrum and can have multiple sites of origins, with a high probability of metastasis through cerebrospinal fluid (CSF). PNET has five subtypes of tumors: neuroblastoma, ganglioneuroblastoma, medulloepithelioma, ependymoblastoma, and not otherwise specified PNET. It is similar to medulloblastoma regarding histology but different regarding genetic factors and tumor site. It is a rare disease occurring mostly among children, accoun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
