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ZEB2
Zinc finger E-box-binding homeobox 2 is a protein that in humans is encoded by the ''ZEB2'' gene. The ZEB2 protein is a transcription factor that plays a role in the transforming growth factor β (TGFβ) signaling pathways that are essential during early fetal development. Function ZEB2 (previously also known as SMADIP1, SIP1) and its mammalian paralog ZEB1 belongs to the Zeb family within the ZF (zinc finger) class of homeodomain transcription factors. ZEB2 protein has 8 zinc fingers and 1 homeodomain. The structure of the homeodomain shown on the right. ZEB2 interacts with receptor-mediated, activated full-length SMADs. The activation of TGFβ receptors brings about the phosphorylation of intracellular effector molecules, R-SMADs. ZEB2 is an R-SMAD-binding protein and acts as a transcriptional corepressor. It is involved in the timing of the conversion of neuroepithelial cells into radial glial cells in early development, a mechanism thought to allow for the large difference ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mowat–Wilson Syndrome
Mowat–Wilson syndrome is a rare genetic disorder that was clinically delineated by David R. Mowat and Meredith J. Wilson in 1998. The condition affects both males and females, has been described in various countries and ethnic groups around the world, and occurs in approximately 1 in 50,000-100,000 births. Presentation This autosomal dominant disorder is characterized by a number of health defects including Hirschsprung disease, intellectual disability, epilepsy, delayed growth and motor development, congenital heart disease, genitourinary anomalies and absence of the corpus callosum. However, Hirschsprung's disease is not present in all infants with Mowat–Wilson syndrome and therefore it is not a required diagnostic criterion.Todo A, Harrington JWNew-onset seizures in infant with square facies, hypospadias, and Hirschsprung disease Consultant for Pediatricians. 2010;9:103-107. Distinctive physical features include microcephaly, narrow chin, cupped ears with uplifted lobes with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hirschsprung's Disease
Hirschsprung's disease (HD or HSCR) is a birth defect in which nerves are missing from parts of the intestine. The most prominent symptom is constipation. Other symptoms may include vomiting, abdominal pain, diarrhea and slow growth. Symptoms usually become apparent in the first two months of life. Complications may include enterocolitis, megacolon, bowel obstruction and intestinal perforation. The disorder may occur by itself or in association with other genetic disorders such as Down syndrome or Waardenburg syndrome. About half of isolated cases are linked to a specific genetic mutation, and about 20% occur within families. Some of these occur in an autosomal dominant manner. The cause of the remaining cases is unclear. If otherwise normal parents have one child with the condition, the next child has a 4% risk of being affected. The condition is divided into two main types, short-segment and long-segment, depending on how much of the bowel is affected. Rarely, the small bowel m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZEB1
Zinc finger E-box-binding homeobox 1 is a protein that in humans is encoded by the ''ZEB1'' gene. ZEB1 (previously known as TCF8) encodes a zinc finger and homeodomain transcription factor that represses T-lymphocyte-specific IL2 gene expression by binding to a negative regulatory domain 100 nucleotides 5-prime of the IL2 transcription start site. ZEB1 and its mammalian paralog ZEB2 belongs to the Zeb family within the ZF (zinc finger) class of homeodomain transcription factors. ZEB1 protein has 7 zinc fingers and 1 homeodomain. The structure of the homeodomain is shown on the right. Clinical significance Mutations of the gene are linked to posterior polymorphous corneal dystrophy 3. ZEB1 downregulates E-cadherin and induces epithelial to mesenchymal transition in breast and other carcinomas. A recent study suggested its contributing role in lung cancer Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cranial Nerve Ganglia
In neuroanatomy, the cranial nerve ganglia are ganglia of certain cranial nerves. They can be parasympathetic or sensory. All cranial nerve ganglia are bilateral. Parasympathetic The four cranial parasympathetic ganglia are: *ciliary ganglion *pterygopalatine ganglion *otic ganglion *submandibular ganglion Sensory * trigeminal ganglion (CN V) * geniculate ganglion (CN VII) * spiral ganglion (CN VIII) * vestibular ganglion aka Scarpa's ganglion (CN VIII) * superior ganglion of glossopharyngeal nerve * inferior ganglion of glossopharyngeal nerve * superior ganglion of vagus nerve * inferior ganglion of vagus nerve The inferior ganglion of the vagus nerve, (nodose ganglion) is a sensory ganglion of the peripheral nervous system. It is located within the jugular foramen where the vagus nerve exits the skull. It is larger than and below the superior ganglion ... References Nervous ganglia {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication (translesion synthesis). Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutation is the ultimate source o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanocytes
Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart. Melanin is a dark pigment primarily responsible for skin color. Once synthesized, melanin is contained in special organelles called melanosomes which can be transported to nearby keratinocytes to induce pigmentation. Thus darker skin tones have more melanosomes present than lighter skin tones. Functionally, melanin serves as protection against UV radiation. Melanocytes also have a role in the immune system. Function Through a process called melanogenesis, melanocytes produce melanin, which is a pigment found in the skin, eyes, hair, nasal cavity, and inner ear. This melanogenesis leads to a long-lasting pigmentation, which is in contrast to the pigmentation that originates from oxidation of already-existing melanin. There are both ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enteric Nervous System
The enteric nervous system (ENS) or intrinsic nervous system is one of the main divisions of the autonomic nervous system (ANS) and consists of a mesh-like system of neurons that governs the function of the gastrointestinal tract. It is capable of acting independently of the sympathetic and parasympathetic nervous systems, although it may be influenced by them. The ENS is nicknamed the "second brain". It is derived from neural crest cells. The enteric nervous system is capable of operating independently of the brain and spinal cord, but does rely on innervation from the vagus nerve and prevertebral ganglia in healthy subjects. However, studies have shown that the system is operable with a severed vagus nerve. The neurons of the enteric nervous system control the motor functions of the system, in addition to the secretion of gastrointestinal enzymes. These neurons communicate through many neurotransmitters similar to the CNS, including acetylcholine, dopamine, and serotonin. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympathetic Ganglionic Chain
The sympathetic trunks (sympathetic chain, gangliated cord) are a paired bundle of nerve fibers that run from the base of the skull to the coccyx. They are a major component of the sympathetic nervous system. Structure The sympathetic trunk lies just lateral to the vertebral bodies for the entire length of the vertebral column. It interacts with the anterior rami of spinal nerves by way of rami communicantes. The sympathetic trunk permits preganglionic fibers of the sympathetic nervous system to ascend to spinal levels superior to T1 and descend to spinal levels inferior to L2/3.Greenstein B., Greenstein A. (2002): Color atlas of neuroscience – Neuroanatomy and neurophysiology. Thieme, Stuttgart – New York, . The superior end of it is continued upward through the carotid canal into the skull, and forms a plexus on the internal carotid artery; the inferior part travels in front of the coccyx, where it converges with the other trunk at a structure known as the ganglion impar. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Root Ganglion
A dorsal root ganglion (or spinal ganglion; also known as a posterior root ganglion) is a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve. The cell bodies of sensory neurons known as first-order neurons are located in the dorsal root ganglia. The axons of dorsal root ganglion neurons are known as afferents. In the peripheral nervous system, afferents refer to the axons that relay sensory information into the central nervous system (i.e. the brain and the spinal cord). Structure The neurons comprising the dorsal root ganglion are of the pseudo-unipolar type, meaning they have a cell body (soma) with two branches that act as a single axon, often referred to as a ''distal process'' and a ''proximal process''. Unlike the majority of neurons found in the central nervous system, an action potential in posterior root ganglion neuron may initiate in the ''distal process'' in the periphery, bypass the cell body, and continue to propagate along the ''proximal process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain Size
The size of the brain is a frequent topic of study within the fields of anatomy, biological anthropology, animal science and evolution. Brain size is sometimes measured by weight and sometimes by volume (via MRI scans or by skull volume). Neuroimaging intelligence testing can be used to study the volumetric measurements of the brain. Regarding "intelligence testing", a question that has been frequently investigated is the relation of brain size to intelligence. This question is quite controversial and will be addressed further in the section on intelligence. The measure of brain size and cranial capacity is not just important to humans, but to all mammals. Humans In humans, the right cerebral hemisphere is typically larger than the left, whereas the cerebellar hemispheres are typically closer in size. The adult human brain weighs on average about . In men the average weight is about 1370 g and in women about 1200 g. The volume is around 1260 cm3 in men and 1130 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
