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XYLT1
Xylosyltransferase 1 is an enzyme that in humans is encoded by the ''XYLT1'' gene. Xylosyltransferase (XT; EC 2.4.2.26) catalyzes the transfer of UDP-xylose to serine residues within XT recognition sequences of target proteins. Addition of this xylose to the core protein is required for the biosynthesis of the glycosaminoglycan chains characteristic of proteoglycans. upplied by OMIMref name="entrez" /> Clinical relevance Baratela-Scott syndrome In 2012 Baratela-Scott syndrome was identified in humans. A GGC repeat expansion, and methylation of exon 1 of XYLT1 is a common pathogenic variant in Baratela-Scott syndrome. Patients with Bartarlla-Scott syndrome exhibit abnormal development of the skeleton, characteristic facial features, and cognitive developmental delay. Skeletal problems include knee cap in the wrong position, short long bones with mild changes to the narrow portion, short palm bones with stub thumbs, short thigh necks, shallow hip sockets, and malformation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xylose
Xylose ( , , "wood") is a sugar first isolated from wood, and named for it. Xylose is classified as a monosaccharide of the aldopentose type, which means that it contains five carbon atoms and includes an aldehyde functional group. It is derived from hemicellulose, one of the main constituents of biomass. Like most sugars, it can adopt several structures depending on conditions. With its free aldehyde group, it is a reducing sugar. Structure The acyclic form of xylose has chemical formula . The cyclic hemiacetal isomers are more prevalent in solution and are of two types: the pyranoses, which feature six-membered rings, and the furanoses, which feature five-membered rings (with a pendant group). Each of these rings is subject to further isomerism, depending on the relative orientation of the anomeric hydroxy group. The dextrorotary form, -xylose, is the one that usually occurs endogenously in living things. A levorotary form, -xylose, can be synthesized. Occurren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patellar Dislocation
A patellar dislocation is a knee injury in which the patella (kneecap) slips out of its normal position. Often the knee is partly bent, painful and knee effusion, swollen. The patella is also often felt and seen out of place. Complications may include a patella fracture or arthritis. A patellar dislocation typically occurs when the knee is straight and the lower leg is bent outwards when twisting. Occasionally, it occurs when the knee is bent and the patella is struck directly. Commonly associated sports include soccer, gymnastics, and ice hockey. Dislocations nearly always occur away from the midline. Diagnosis is typically based on symptoms and supported by radiography, X-rays. Reduction is generally done by pushing the patella towards the midline while straightening the knee. After reduction, the leg is generally Splint (medicine), splinted in a straight position for a few weeks. This is then followed by physical therapy. Surgery after a first dislocation is generally of un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nasal Bridge
The nasal bridge is the upper part of the nose, where the nasal bones and surrounding soft tissues provide structural support. While commonly discussed in human anatomy, nasal bridges exist in various forms across many vertebrates, particularly mammals. The shape, size, and function of the nasal bridge are influenced by evolutionary adaptations, playing a key role in Respiration (physiology), respiration, sense of smell, and thermoregulation. Anatomy Humans In humans, the nasal bridge is the elevated region of the human nose, nose between the eyes. It is primarily formed by the two small, oblong nasal bones, which meet at the midline to form the internasal suture. The nasal bridge extends from the nasal root, where the nose meets the forehead, to the lower edge of the nasal bones. Laterally, it reaches the inner canthi, the medial corners of the eyes, creating a saddle-shaped contour across the upper nose. The height and shape of the nasal bridge vary among individuals and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platyspondyly
Congenital vertebral anomalies are a collection of malformations of the spine. Most, around 85%, are not clinically significant, but they can cause compression of the spinal cord by deforming the vertebral canal or causing instability. This condition occurs in the womb. Congenital vertebral anomalies include alterations of the shape and number of vertebrae. Lumbarization and sacralization ''Lumbarization'' is an anomaly in the spine. It is defined by the nonfusion of the first and second segments of the sacrum. The lumbar spine subsequently appears to have six vertebrae or segments, not five. This sixth lumbar vertebra is known as a transitional vertebra. Conversely the sacrum appears to have only four segments instead of its designated five segments. Lumbosacral transitional vertebrae consist of the process of the last lumbar vertebra fusing with the first sacral segment. While only around 10 percent of adults have a spinal abnormality due to genetics, a sixth lumbar vertebra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetabulum
The acetabulum (; : acetabula), also called the cotyloid cavity, is a wikt:concave, concave surface of the pelvis. The femur head, head of the femur meets with the pelvis at the acetabulum, forming the Hip#Articulation, hip joint. Structure There are three bones of the ''os coxae'' (hip bone) that come together to form the ''acetabulum''. Contributing a little more than two-fifths of the structure is the ischium, which provides lower and side boundaries to the acetabulum. The Ilium (bone), ilium forms the upper boundary, providing a little less than two-fifths of the structure of the acetabulum. The rest is formed by the Pubis (bone), pubis, near the midline. It is bounded by a prominent uneven rim, thick and strong on top, which serves as the point of attachment for the acetabular labrum. The acetabular labrum reduces the size of the opening of the acetabulum and deepens the surface of the hip joint. At the lower part of the acetabulum is the acetabular notch, which is continuo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femur Neck
The femoral neck (also femur neck or neck of the femur) is a flattened pyramidal process of bone, connecting the femoral head with the body of femur, femoral shaft, and forming with the latter a wide angle opening medialward. Structure The neck is flattened from before backward, contracted in the middle, and broader laterally than medially. The vertical diameter of the lateral half is increased by the obliquity of the lower edge, which slopes downward to join the body at the level of the lesser trochanter, so that it measures one-third more than the antero-posterior diameter. The medial half is smaller and of a more circular shape. The anterior surface of the neck is perforated by numerous vascular wikt:foramen, foramina. Along the upper part of the line of junction of the anterior surface with the head is a shallow groove, best marked in elderly subjects; this groove lodges the orbicular fibers of the capsule of the hip-joint, hip joint. The posterior surface is smooth, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metacarpals
In human anatomy, the metacarpal bones or metacarpus, also known as the "palm bones", are the appendicular skeleton, appendicular bones that form the intermediate part of the hand between the phalanges (fingers) and the carpal bones (wrist, wrist bones), which joint, articulate with the forearm. The metacarpal bones are homologous to the metatarsal bones in the foot. Structure The metacarpals form a transverse arch to which the rigid row of distal carpal bones are fixed. The peripheral metacarpals (those of the thumb and little finger) form the sides of the cup of the palmar gutter and as they are brought together they deepen this concavity. The index metacarpal is the most firmly fixed, while the thumb metacarpal articulates with the trapezium and acts independently from the others. The middle metacarpals are tightly united to the carpus by intrinsic interlocking bone elements at their bases. The ring metacarpal is somewhat more mobile while the fifth metacarpal is semi-indepen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brachydactyly
Brachydactyly () is a medical term denoting the presence of abnormally short digits (fingers or toes) at birth. The shortness is relative to the length of other long bones and other parts of the body. Brachydactyly is an inherited, dominant trait. It most often occurs as an isolated dysmelia, but can also occur with other anomalies as part of many congenital syndromes. Brachydactyly may also be a signal that one is at risk for congenital heart disease due to the association between congenital heart disease and Carpenter syndrome and the link between Carpenter syndrome and brachydactyly. Nomograms for normal values of finger length as a ratio to other body measurements have been published. In clinical genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian ..., the most com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaphyseal
The metaphysis (: metaphyses) is the neck portion of a long bone between the epiphysis and the diaphysis. It contains the growth plate, the part of the bone that grows during childhood, and as it grows it ossifies near the diaphysis and the epiphyses. The metaphysis contains a diverse population of cells including Mesenchymal stem cell, mesenchymal stem cells, which give rise to Osteoblast, bone and Adipocyte, fat cells, as well as Hematopoietic stem cell, hematopoietic stem cells which give rise to a variety of Blood cell, blood cells as well as bone-destroying cells called Osteoclast, osteoclasts. Thus the metaphysis contains a highly metabolic set of tissues including Spongy bone, trabecular (spongy) bone, Blood vessel, blood vessels, as well as Marrow adipose tissue, marrow adipose tissue (MAT). The metaphysis may be divided anatomically into three components based on tissue content: a cartilaginous component (epiphyseal plate), a bony component (metaphysis) and a Fibrous jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Bones
The long bones are those that are longer than they are wide. They are one of five types of bones: long, short, flat, irregular and sesamoid. Long bones, especially the femur and tibia, are subjected to most of the load during daily activities and they are crucial for skeletal mobility. They grow primarily by elongation of the diaphysis, with an epiphysis at each end of the growing bone. The ends of epiphyses are covered with hyaline cartilage ("articular cartilage"). The longitudinal growth of long bones is a result of endochondral ossification at the epiphyseal plate. Bone growth in length is stimulated by the production of growth hormone (GH), a secretion of the anterior lobe of the pituitary gland. The long bone category includes the femora, tibiae, and fibulae of the legs; the humeri, radii, and ulnae of the arms; metacarpals and metatarsals of the hands and feet, the phalanges of the fingers and toes, and the clavicles or collar bones. The long bones of the human leg m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeleton
A skeleton is the structural frame that supports the body of most animals. There are several types of skeletons, including the exoskeleton, which is a rigid outer shell that holds up an organism's shape; the endoskeleton, a rigid internal frame to which the organs and soft tissues attach; and the hydroskeleton, a flexible internal structure supported by the hydrostatic pressure of body fluids. Vertebrates are animals with an endoskeleton centered around an axial vertebral column, and their skeletons are typically composed of bones and cartilages. Invertebrates are other animals that lack a vertebral column, and their skeletons vary, including hard-shelled exoskeleton (arthropods and most molluscs), plated internal shells (e.g. cuttlebones in some cephalopods) or rods (e.g. ossicles in echinoderms), hydrostatically supported body cavities (most), and spicules (sponges). Cartilage is a rigid connective tissue that is found in the skeletal systems of vertebrates and invert ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
