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Elastin
Elastin is a protein that in humans is encoded by the ''ELN'' gene. Elastin is a key component of the extracellular matrix in gnathostomes (jawed vertebrates). It is highly elastic and present in connective tissue allowing many tissues in the body to resume their shape after stretching or contracting. Elastin helps skin to return to its original position when it is poked or pinched. Elastin is also an important load-bearing tissue in the bodies of vertebrates and used in places where mechanical energy is required to be stored. Function The ''ELN'' gene encodes a protein that is one of the two components of elastic fibers. The encoded protein is rich in hydrophobic amino acids such as glycine and proline, which form mobile hydrophobic regions bounded by crosslinks between lysine residues. Multiple transcript variants encoding different isoforms have been found for this gene. Elastin's soluble precursor is tropoelastin. The characterization of disorder is consistent with an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastic Fibers
Elastic fibers (or yellow fibers) are an essential component of the extracellular matrix composed of bundles of proteins (elastin) which are produced by a number of different cell types including fibroblasts, endothelial, smooth muscle, and airway epithelial cells. These fibers are able to stretch many times their length, and snap back to their original length when relaxed without loss of energy. Elastic fibers include elastin, elaunin and oxytalan. Elastic tissue is classified as "connective tissue proper". Elastic fibers are formed via elastogenesis, a highly complex process involving several key proteins including fibulin-4, fibulin-5, latent transforming growth factor β binding protein 4, and microfibril associated protein 4. In this process tropoelastin, the soluble monomeric precursor to elastic fibers is produced by elastogenic cells and chaperoned to the cell surface. Following excretion from the cell, tropoelastin self associates into ~200 nm particles by coace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extracellular Matrix
In biology, the extracellular matrix (ECM), also called intercellular matrix, is a three-dimensional network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and biochemical support to surrounding cells. Because multicellularity evolved independently in different multicellular lineages, the composition of ECM varies between multicellular structures; however, cell adhesion, cell-to-cell communication and differentiation are common functions of the ECM. The animal extracellular matrix includes the interstitial matrix and the basement membrane. Interstitial matrix is present between various animal cells (i.e., in the intercellular spaces). Gels of polysaccharides and fibrous proteins fill the interstitial space and act as a compression buffer against the stress placed on the ECM. Basement membranes are sheet-like depositions of ECM on which various epithelial cells rest. Each type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Williams Syndrome
Williams syndrome (WS) is a genetic disorder that affects many parts of the body. Facial features frequently include a broad forehead, underdeveloped chin, short nose, and full cheeks. Mild to moderate intellectual disability is observed in people with WS, with particular challenges with visual spatial tasks such as drawing. Verbal skills are relatively unaffected. Many people with WS have an outgoing personality, an openness to engaging with other people, and a happy disposition. Medical issues with teeth, heart problems (especially supravalvular aortic stenosis), and periods of high blood calcium are common. Williams syndrome is caused by a genetic abnormality, specifically a deletion of about 27 genes from the long arm of one of the two chromosome 7s. Typically, this occurs as a random event during the formation of the egg or sperm from which a person develops. In a small number of cases, it is inherited from an affected parent in an autosomal dominant manner. The differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha 1-antitrypsin
Alpha-1 antitrypsin or α1-antitrypsin (A1AT, α1AT, A1A, or AAT) is a protein belonging to the serpin superfamily. It is encoded in humans by the ''SERPINA1'' gene. A protease inhibitor, it is also known as alpha1–proteinase inhibitor (A1PI) or alpha1-antiproteinase (A1AP) because it inhibits various proteases (not just trypsin). In older biomedical literature it was sometimes called serum trypsin inhibitor (STI, dated terminology), because its capability as a trypsin inhibitor was a salient feature of its early study. As a type of enzyme inhibitor, it protects tissues from enzymes of inflammatory cells, especially neutrophil elastase, and has a reference range in blood of 0.9–2.3 g/L (in the US the reference range is expressed as mg/dL or micromoles), but the concentration can rise manyfold upon acute inflammation. When the blood contains inadequate amounts of A1AT or functionally defective A1AT (such as in alpha-1 antitrypsin deficiency), neutrophil elastase is excessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoaging
Photoaging or photoageing (also known as "dermatoheliosis") is a term used for the characteristic changes to skin induced by chronic UVA and UVB exposure. Tretinoin is the best studied retinoid in the treatment of photoaging. The deterioration of biological functions and ability to manage metabolic stress is one of the major consequences of the aging process. Aging is a complex, progressive process that leads to functional and aesthetic changes in the skin. This process can result from both intrinsic (i.e., genetically determined) as well as extrinsic processes (i.e., environmental factors). Photoaging is attributed to continuous, long-term exposure to ultraviolet (UV) radiation of approximately 300–400 nm, either natural or synthetic, on an intrinsically aged skin. Effects of UV light Molecular and genetic changes UVB rays are a primary mutagen that can only penetrate through the epidermal (outermost) layer of the skin, resulting in DNA mutations. These mutations arise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cutis Laxa
Cutis laxa or pachydermatocele is a group of rare connective tissue disorders in which the skin becomes inelastic and hangs loosely in folds. Signs and symptoms It is characterised by skin that is loose, hanging, wrinkled, and lacking in elasticity. The loose skin can be either generalised or localised. Biopsies have shown reduction and degeneration of dermal elastic fibres in the affected areas of skin. The loose skin is often most noticeable on the face, resulting in a prematurely aged appearance. The affected areas of skin may be thickened and dark. In addition, the joints may be loose ( hypermobile) because of lax ligaments and tendons. When cutis laxa is severe, it can also affect the internal organs. The lungs, heart (supravalvular pulmonary stenosis), intestines, or arteries may be affected with a variety of severe impairments. In some cases, hernias and outpouching of the bladder can be observed. Patients can also present with whites of the eyes that are blue. Causes I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. When severe, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney problems, depending on which arteries are affected. The exact cause is not known and is proposed to be multifactorial. Risk factors include abnormal cholesterol levels, elevated levels of inflammatory markers, high blood pressure, diabetes, smoking, obesity, family history, genetic, and an unhealthy diet. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. The narrowing of arteries limits the flow of oxygen-rich blood to parts of the body. Diagnosis is based upon a physical exam, electrocardiogram, and exercise stress test, amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Connective Tissue
Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. The three meninges, membranes that envelop the brain and spinal cord are composed of connective tissue. Most types of connective tissue consists of three main components: elastic and collagen fibers, ground substance, and cells. Blood, and lymph are classed as specialized fluid connective tissues that do not contain fiber. All are immersed in the body water. The cells of connective tissue include fibroblasts, adipocytes, macrophages, mast cells and leucocytes. The term "connective tissue" (in German, ''Bindegewebe'') was introduced in 1830 by Johannes Peter Müller. The tissue was already recognized as a distinct class in the 18th century. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinic Elastosis
Actinic elastosis, also known as solar elastosis, is an accumulation of abnormal elastin (elastic tissue) in the dermis of the skin, or in the conjunctiva of the human eye, eye, which occurs as a result of the cumulative effects of prolonged and excessive sun exposure, a process known as photoaging. Signs and symptoms Actinic elastosis usually appears as thickened, dry, wrinkled skin. Several clinical variants have been recorded. One of the most readily identifiable is the thickened, deeply fissured skin seen on the back of the chronically sun-exposed neck, known as cutis rhomboidalis nuchae. These features are a part of the constellation of changes that are seen in photoaged skin. Causes The origin of the elastotic material in the dermis remains a subject of debate. Theories on the formation of the elastotic material include actinic stimulation of fibroblasts, promoting synthesis of this material, or that the material is a degradation product of collagen, elastin, or both. Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinic Elastosis
Actinic elastosis, also known as solar elastosis, is an accumulation of abnormal elastin (elastic tissue) in the dermis of the skin, or in the conjunctiva of the human eye, eye, which occurs as a result of the cumulative effects of prolonged and excessive sun exposure, a process known as photoaging. Signs and symptoms Actinic elastosis usually appears as thickened, dry, wrinkled skin. Several clinical variants have been recorded. One of the most readily identifiable is the thickened, deeply fissured skin seen on the back of the chronically sun-exposed neck, known as cutis rhomboidalis nuchae. These features are a part of the constellation of changes that are seen in photoaged skin. Causes The origin of the elastotic material in the dermis remains a subject of debate. Theories on the formation of the elastotic material include actinic stimulation of fibroblasts, promoting synthesis of this material, or that the material is a degradation product of collagen, elastin, or both. Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reticular Dermis
The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided into two layers, the superficial area adjacent to the epidermis called the papillary region and a deep thicker area known as the reticular dermis.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Pages 1, 11–12. . The dermis is tightly connected to the epidermis through a basement membrane. Structural components of the dermis are collagen, elastic fibers, and extrafibrillar matrix.Marks, James G; Miller, Jeffery (2006). ''Lookingbill and Marks' Principles of Dermatology'' (4th ed.). Elsevier Inc. Page 8–9. . It also contains mechanoreceptors that provide the sense of touch and thermoreceptors that provide the sense of heat. In addition, hair follicles, sw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Papillary Dermis
The dermis or corium is a layer of skin between the epidermis (with which it makes up the cutis) and subcutaneous tissues, that primarily consists of dense irregular connective tissue and cushions the body from stress and strain. It is divided into two layers, the superficial area adjacent to the epidermis called the papillary region and a deep thicker area known as the reticular dermis.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology'' (10th ed.). Saunders. Pages 1, 11–12. . The dermis is tightly connected to the epidermis through a basement membrane. Structural components of the dermis are collagen, elastic fibers, and extrafibrillar matrix.Marks, James G; Miller, Jeffery (2006). ''Lookingbill and Marks' Principles of Dermatology'' (4th ed.). Elsevier Inc. Page 8–9. . It also contains mechanoreceptors that provide the sense of touch and thermoreceptors that provide the sense of heat. In addition, hair follicles, sw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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