|
Werner Syndrome
Werner syndrome (WS) or Werner's syndrome, also known as "adult progeria",James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . is a rare, autosomal recessive disorder which is characterized by the appearance of premature aging. Werner syndrome is named after the German scientist Otto Werner. He identified the syndrome in four siblings observed with premature aging, which he explored as the subject of his dissertation of 1904. It has a global incidence rate of less than 1 in 100,000 live births (although incidence in Japan and Sardinia is higher, affecting 1 in 20,000–40,000 and 1 in 50,000, respectively). 1,300 cases had been reported as of 2006. Affected individuals typically grow and develop normally until puberty; the mean age of diagnosis is twenty-four, often realized when the adolescent growth spurt is not observed. The youngest person diagnosed was six years old. The median and mean ages of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heredity
Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents. Through heredity, variations between individuals can accumulate and cause species to evolve by natural selection. The study of heredity in biology is genetics. Overview In humans, eye color is an example of an inherited characteristic: an individual might inherit the "brown-eye trait" from one of the parents. Inherited traits are controlled by genes and the complete set of genes within an organism's genome is called its genotype. The complete set of observable traits of the structure and behavior of an organism is called its phenotype. These traits arise from the interaction of its genotype with the environment. As a result, many aspects of an organism's phenotype are not inherited. For example, suntanned ski ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malleolus
A malleolus is the bony prominence on each side of the human ankle. Each leg is supported by two bones, the tibia on the inner side (medial) of the leg and the fibula on the outer side (lateral) of the leg. The medial malleolus is the prominence on the inner side of the ankle, formed by the lower end of the tibia. The lateral malleolus is the prominence on the outer side of the ankle, formed by the lower end of the fibula. The word ''malleolus'' (), plural ''malleoli'' (), comes from Latin and means "small hammer". (It is cognate with ''mallet''.) Medial malleolus The medial malleolus is found at the foot end of the tibia. The medial surface of the lower extremity of tibia is prolonged downward to form a strong pyramidal process, flattened from without inward - the medial malleolus. * The ''medial surface'' of this process is convex and subcutaneous. * The ''lateral'' or ''articular surface'' is smooth and slightly concave, and articulates with the talus. * The ''anterior ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA. Gene expression is summarized in the central dogma of molecular biology first formulated by Francis Crick in 1958, further developed in his 1970 article, and expanded by the subsequent discoveries of reverse transcription and RNA replication. The process of gene expression is used by all known life— eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and utilized by viruses—to generate the macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transcription (genetics)
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called non-coding RNAs (ncRNAs). mRNA comprises only 1–3% of total RNA samples. Less than 2% of the human genome can be transcribed into mRNA ( Human genome#Coding vs. noncoding DNA), while at least 80% of mammalian genomic DNA can be actively transcribed (in one or more types of cells), with the majority of this 80% considered to be ncRNA. Both DNA and RNA are nucleic acids, which use base pairs of nucleotides as a complementary language. During transcription, a DNA sequence is read by an RNA polymerase, which produces a complementary, antiparallel RNA strand called a primary transcript. Transcription proceeds in the following general steps: # RNA polymerase, together with one or more general transcription factors, binds to promote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meningioma
Meningioma, also known as meningeal tumor, is typically a slow-growing tumor that forms from the meninges, the membranous layers surrounding the brain and spinal cord. Symptoms depend on the location and occur as a result of the tumor pressing on nearby tissue. Many cases never produce symptoms. Occasionally seizures, dementia, trouble talking, vision problems, one sided weakness, or loss of bladder control may occur. Risk factors include exposure to ionizing radiation such as during radiation therapy, a family history of the condition, and neurofibromatosis type 2. As of 2014 they do not appear to be related to cell phone use. They appear to be able to form from a number of different types of cells including arachnoid cells. Diagnosis is typically by medical imaging. If there are no symptoms, periodic observation may be all that is required. Most cases that result in symptoms can be cured by surgery. Following complete removal fewer than 20% recur. If surgery is not possib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malignancy
Malignancy () is the tendency of a medical condition to become progressively worse. Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not self-limited in its growth, is capable of invading into adjacent tissues, and may be capable of spreading to distant tissues. A benign tumor has none of those properties. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis. Malignant tumors are also characterized by genome instability, so that cancers, as assessed by whole genome sequencing, frequently have between 10,000 and 100,000 mutations in their entire genomes. Cancers usually show tumour heterogeneity, containing multiple subclones. They also frequently have reduced expression of DNA repair enzymes due to epigenetic methylation of DNA repair genes or altered microRNAs that control DNA repair gene expression. Tumours can be detected through the visual ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telangiectasia
Telangiectasias, also known as spider veins, are small dilated blood vessels that can occur near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. These dilated blood vessels can develop anywhere on the body, but are commonly seen on the face around the nose, cheeks and chin. Dilated blood vessels can also develop on the legs, although when they occur on the legs, they often have underlying venous reflux or "hidden varicose veins" (see Venous hypertension section below). When found on the legs, they are found specifically on the upper thigh, below the knee joint and around the ankles. Many patients with spider veins seek the assistance of physicians who specialize in vein care or peripheral vascular disease. These physicians are called vascular surgeons or phlebologists. More recently, interventional radiologists have started treating venous problems. Some telangiectasias are due to developmental abnormalities that can closely mimic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteoporosis
Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and consequent increase in fracture risk. It is the most common reason for a broken bone among the elderly. Bones that commonly break include the vertebrae in the spine, the bones of the forearm, and the hip. Until a broken bone occurs there are typically no symptoms. Bones may weaken to such a degree that a break may occur with minor stress or spontaneously. After the broken bone heals, the person may have chronic pain and a decreased ability to carry out normal activities. Osteoporosis may be due to lower-than-normal maximum bone mass and greater-than-normal bone loss. Bone loss increases after the menopause due to lower levels of estrogen, and after ' andropause' due to lower levels of testosterone. Osteoporosis may also occur due to a number of diseases or treatments, including alcoholism, anorexia, hyperthyroidism, k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type 2 Diabetes
Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, and unexplained weight loss. Symptoms may also include increased hunger, feeling tired, and sores that do not heal. Often symptoms come on slowly. Long-term complications from high blood sugar include heart disease, strokes, diabetic retinopathy which can result in blindness, kidney failure, and poor blood flow in the limbs which may lead to amputations. The sudden onset of hyperosmolar hyperglycemic state may occur; however, ketoacidosis is uncommon. Type 2 diabetes primarily occurs as a result of obesity and lack of exercise. Some people are genetically more at risk than others. Type 2 diabetes makes up about 90% of cases of diabetes, with the other 10% due primarily to type 1 diabetes and gestational diabetes. In type ... [...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] |
Calcinosis
Calcinosis is the formation of calcium deposits in any soft tissue. It is a rare condition that has many different causes. These range from infection and injury to systemic diseases like kidney failure. Types Dystrophic calcification The most common type of calcinosis is dystrophic calcification. This type of calcification can occur as a response to any soft tissue damage, including that involved in implantation of medical devices. Metastatic calcification Metastatic calcification involves a systemic calcium excess imbalance, which can be caused by hypercalcemia, kidney failure, milk-alkali syndrome, lack or excess of other minerals, or other causes. Tumoral calcinosis The cause of the rare condition of tumoral calcinosis is not entirely understood. It is generally characterized by large, globular calcifications near joints. See also * Calcification * Calcinosis cutis * Dermatomyositis * Fahr's syndrome Primary Indiana familial brain calcification Initial Posting: Apri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arteriosclerosis
Arteriosclerosis is the thickening, hardening, and loss of elasticity of the walls of arteries. This process gradually restricts the blood flow to one's organs and tissues and can lead to severe health risks brought on by atherosclerosis, which is a specific form of arteriosclerosis caused by the buildup of fatty plaques, cholesterol, and some other substances in and on the artery walls. It can be brought on by smoking, a bad diet, or many genetic factors. Atherosclerosis is the primary cause of coronary artery disease (CAD) and stroke, with multiple genetic and environmental contributions. Genetic-epidemiologic studies have identified a long list of genetic and non-genetic risk factors for CAD. However, such studies indicate that family history is the most significant independent risk factor. Signs and symptoms The signs and symptoms of arteriosclerosis depend on the vessel affected by the disease. If affecting cerebral or ophthalmic vessels, as in cerebrovascular accidents ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
