|
Chordoma
Chordoma is a rare slow-growing neoplasm thought to arise from cellular remnants of the notochord. The evidence for this is the location of the tumors (along the neuraxis), the similar immunohistochemical staining patterns, and the demonstration that notochordal cells are preferentially left behind in the clivus and sacrococcygeal regions when the remainder of the notochord regresses during fetal life. In layman's terms, chordoma is a type of spinal cancer. Presentation Chordomas can arise from bone in the skull base and anywhere along the spine. The two most common locations are cranially at the clivus and in the sacrum at the bottom of the spine. Sacral chordoma is presented with chronic low back pain. Genetics A small number of families have been reported in which multiple relatives have been affected by chordoma. In four of these families, duplication of the brachyury gene was found to be responsible for causing chordoma. A possible association with tuberous sclero ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sacrum
The sacrum (plural: ''sacra'' or ''sacrums''), in human anatomy, is a large, triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part of the pelvic cavity, between the two wings of the pelvis. It forms joints with four other bones. The two projections at the sides of the sacrum are called the alae (wings), and articulate with the ilium at the L-shaped sacroiliac joints. The upper part of the sacrum connects with the last lumbar vertebra (L5), and its lower part with the coccyx (tailbone) via the sacral and coccygeal cornua. The sacrum has three different surfaces which are shaped to accommodate surrounding pelvic structures. Overall it is concave (curved upon itself). The base of the sacrum, the broadest and uppermost part, is tilted forward as the sacral promontory internally. The central part is curved outward toward the posterior, allowing greater room for the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachyury
T-box transcription factor T, also known as Brachyury protein, is encoded for in humans by the ''TBXT'' gene. Brachyury functions as a transcription factor within the T-box family of genes. Brachyury homologs have been found in all bilaterian animals that have been screened, as well as the freshwater cnidarian ''Hydra''. History The ''brachyury'' mutation was first described in mice by Nadezhda Alexandrovna Dobrovolskaya-Zavadskaya in 1927 as a mutation that affected tail length and sacral vertebrae in heterozygous animals. In homozygous animals the brachyury mutation is lethal at around embryonic day 10 due to defects in mesoderm formation, notochord differentiation and the absence of structures posterior to the forelimb bud (Dobrovolskaïa-Zavadskaïa, 1927). The name brachyury comes from the Greek ''brakhus'' meaning short and ''oura'' meaning tail. In 2018 HGNC updated the human gene name from ''T'' to ''TBXT'', presumably to overcome difficulties associated with search ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notochord
In anatomy, the notochord is a flexible rod which is similar in structure to the stiffer cartilage. If a species has a notochord at any stage of its life cycle (along with 4 other features), it is, by definition, a chordate. The notochord consists of inner, vacuolated cells covered by fibrous and elastic sheaths, lies along the anteroposterior axis (''front to back''), is usually closer to the dorsal than the ventral surface of the embryo, and is composed of cells derived from the mesoderm. The most commonly cited functions of the notochord are: as a midline tissue that provides directional signals to surrounding tissue during development, as a skeletal (structural) element, and as a vertebral precursor. In lancelets the notochord persists throughout life as the main structural support of the body. In tunicates the notochord is present only in the larval stage, being completely absent in the adult animal. In these invertebrate chordates, the notochord is not vacuolated. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuoles
A vacuole () is a membrane-bound organelle which is present in plant and fungal cells and some protist, animal, and bacterial cells. Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these. The organelle has no basic shape or size; its structure varies according to the requirements of the cell. Discovery Contractile vacuoles ("stars") were first observed by Spallanzani (1776) in protozoa, although mistaken for respiratory organs. Dujardin (1841) named these "stars" as ''vacuoles''. In 1842, Schleiden applied the term for plant cells, to distinguish the structure with cell sap from the rest of the protoplasm. In 1885, de Vries named the vacuole membrane as tonoplast. Function The function and signific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytoplasm
In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol (a gel-like substance), the organelles (the cell's internal sub-structures), and various cytoplasmic inclusions. The cytoplasm is about 80% water and is usually colorless. The submicroscopic ground cell substance or cytoplasmic matrix which remains after exclusion of the cell organelles and particles is groundplasm. It is the hyaloplasm of light microscopy, a highly complex, polyphasic system in which all resolvable cytoplasmic elements are suspended, including the larger organelles such as the ribosomes, mitochondria, the plant plastids, lipid droplets, and vacuoles. Most cellular activities take place within the cytoplasm, such as many metabolic pathways including glycolysis, ... [...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, potentially m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histological
Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope. Although one may divide microscopic anatomy into ''organology'', the study of organs, ''histology'', the study of tissues, and '' cytology'', the study of cells, modern usage places all of these topics under the field of histology. In medicine, histopathology is the branch of histology that includes the microscopic identification and study of diseased tissue. In the field of paleontology, the term paleohistology refers to the histology of fossil organisms. Biological tissues Animal tissue classification There are four basic types of animal tissues: muscle tissue, nervous tissue, connective tissue, and epithelial tissue. All animal tissues are considered to be subtypes of these four principal tissue types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Histopathology Of Chordoma, Annotated
Histopathology (compound of three Greek words: ''histos'' "tissue", πάθος ''pathos'' "suffering", and -λογία ''-logia'' "study of") refers to the microscopic examination of tissue in order to study the manifestations of disease. Specifically, in clinical medicine, histopathology refers to the examination of a biopsy or surgical specimen by a pathologist, after the specimen has been processed and histological sections have been placed onto glass slides. In contrast, cytopathology examines free cells or tissue micro-fragments (as "cell blocks"). Collection of tissues Histopathological examination of tissues starts with surgery, biopsy, or autopsy. The tissue is removed from the body or plant, and then, often following expert dissection in the fresh state, placed in a fixative which stabilizes the tissues to prevent decay. The most common fixative is 10% neutral buffered formalin (corresponding to 3.7% w/v formaldehyde in neutral buffered water, such as phosphate bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platelet-derived Growth Factor Receptor
Platelet-derived growth factor receptors (PDGF-R) are cell surface tyrosine kinase receptors for members of the platelet-derived growth factor (PDGF) family. PDGF subunits -A and -B are important factors regulating cell proliferation, cellular differentiation, cell growth, development and many diseases including cancer. There are two forms of the PDGF-R, alpha and beta each encoded by a different gene. Depending on which growth factor is bound, PDGF-R homo- or heterodimerizes. Mechanism of action The PDGF family consists of PDGF-A, -B, -C and -D, which form either homo- or hetero dimers (PDGF-AA, -AB, -BB, -CC, -DD). The four PDGFs are inactive in their monomeric forms. The PDGFs bind to the protein tyrosine kinase receptors PDGF receptor-α and -β. These two receptor isoforms dimerize upon binding the PDGF dimer, leading to three possible receptor combinations, namely -αα, -ββ and -αβ. The extracellular region of the receptor consists of five immunoglobulin- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CSPG4
Chondroitin sulfate proteoglycan 4, also known as melanoma-associated chondroitin sulfate proteoglycan (MCSP) or neuron-glial antigen 2 (NG2), is a chondroitin sulfate proteoglycan that in humans is encoded by the ''CSPG4'' gene. Function CSPG4 plays a role in stabilizing cell-substratum interactions during early events of melanoma cell spreading on endothelial basement membranes. It represents an integral membrane chondroitin sulfate proteoglycan expressed by human malignant melanoma cells. Implications in disease CSPG4/NG2 is also a hallmark protein of oligodendrocyte progenitor cells (OPCs) and OPC dysfunction has been implicated as a candidate pathophysiological mechanism of familial schizophrenia. A research group investigating the role of genetics in schizophrenia, reported, two rare missense mutations in ''CSPG4'' gene'','' segregating within families (''CSPG4A131T'' and ''CSPG4V901G'' mutations). The researchers also demonstrate that the induced pluripotent stem cells ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrosarcoma
Chondrosarcoma is a bone sarcoma, a primary cancer composed of cells derived from transformed cells that produce cartilage. A chondrosarcoma is a member of a category of tumors of bone and soft tissue known as sarcomas. About 30% of bone sarcomas are chondrosarcomas. It is resistant to chemotherapy and radiotherapy. Unlike other primary bone sarcomas that mainly affect children and adolescents, a chondrosarcoma can present at any age. It more often affects the axial skeleton than the appendicular skeleton. Types Symptoms and signs * Back or thigh pain * Sciatica * Bladder Symptoms * Unilateral edema Causes The cause is unknown. There may be a history of enchondroma or osteochondroma. A small minority of secondary chondrosarcomas occur in people with Maffucci syndrome and Ollier disease. It has been associated with faulty isocitrate dehydrogenase 1 and 2 enzymes, which are also associated with gliomas and leukemias. Diagnosis Imaging studies – including radiographs ("x-ray ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDKN2B
Cyclin-dependent kinase 4 inhibitor B also known as multiple tumor suppressor 2 (MTS-2) or p15INK4b is a protein that is encoded by the ''CDKN2B'' gene in humans. Function This gene lies adjacent to the tumor suppressor gene CDKN2A in a region that is frequently mutated, deleted, or disregulated in a wide variety of cancer. This gene encodes a cyclin-dependent kinase inhibitor, also known as p15Ink4b protein, which forms a complex with CDK4 or CDK6, and prevents the activation of the CDK kinases by cyclin D, thus the encoded protein functions as a cell growth regulator that inhibits cell cycle G1 progression. The expression of this gene was found to be dramatically induced by TGF beta, which suggested its role in the TGF beta induced growth inhibition. Two alternatively spliced transcripts of this gene encode proteins that share the N-terminal sequence but completely differ in the C-terminus. Interactions CDKN2B tumor suppressor gene product p15 has been shown to interact wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
