Exostoses
Exostoses, Multiple Hereditary
Osteochondroma
N-Acetylglucosaminyltransferases
Osteochondromatosis
Chondrosarcoma
Ribs
Nail Diseases
Parietal Bone
Osteopoikilosis
Langer-Giedion Syndrome
N-Acetylhexosaminyltransferases
Chromosomes, Human, Pair 8
Chromosomes, Human, Pair 11
Heparitin Sulfate
Periostitis
Molecular and clinical examination of an Italian DEFECT11 family. (1/110)
The DEFECT11 syndrome is a contiguous gene syndrome associated with deletions in the proximal part of chromosome 11p. In this study, we describe in an Italian family the co-existence of multiple exostoses (EXT) and enlarged parietal foramina (FPP), the two major symptoms of this syndrome, with abnormalities of the central nervous system. The latter may be a yet undescribed feature of DEFECT11 syndrome. FISH and molecular analysis allowed us to identify a small deletion on 11p11-p12, further refining the localisation of the FPP gene involved in the DEFECT11 syndrome. (+info)A direct interaction between EXT proteins and glycosyltransferases is defective in hereditary multiple exostoses. (2/110)
Hereditary multiple exostoses (HME) is an autosomal dominant condition in which bony outgrowths occur from the juxtaepiphyseal regions of the long bones. In a few percent of cases these exostoses undergo malignant transformation to chondrosarcomas. HME results from mutations in one of two homologous genes, EXT1 and EXT2. These are members of a new gene family that is conserved from Caenorhabditis elegans to higher vertebrates. In humans this family comprises five genes which are most conserved at their C-termini, but they do not contain any discernible functional motifs and their function(s) is unclear. Indirect evidence suggests that EXT proteins are involved in glycosaminoglycan synthesis, act as tumor suppressors and affect hedgehog signaling. One recent study has also reported that these proteins co-purify with glycosyltransferase (GlcA and GlcNAc transferase) activity and on that basis it has been postulated that they are themselves glycosyl-transferases. We performed two-hybrid screens with a fragment of EXT2 from the region that is most highly conserved in the gene family and identified two interacting proteins: the tumor necrosis factor type 1 associated protein and a novel UDP-GalNAc:poly-peptide N -acetylgalactosaminyltransferase. Significantly, both these interactions were abrogated by a disease-causing EXT mutation, indicating that they are important in the etiology of HME. The EXT2-GalNAc-T5 interaction provides the first direct physical link between EXT proteins and known components of glycosamino-glycan synthesis. (+info)Perlecan maintains the integrity of cartilage and some basement membranes. (3/110)
Perlecan is a heparan sulfate proteoglycan that is expressed in all basement membranes (BMs), in cartilage, and several other mesenchymal tissues during development. Perlecan binds growth factors and interacts with various extracellular matrix proteins and cell adhesion molecules. Homozygous mice with a null mutation in the perlecan gene exhibit normal formation of BMs. However, BMs deteriorate in regions with increased mechanical stress such as the contracting myocardium and the expanding brain vesicles showing that perlecan is crucial for maintaining BM integrity. As a consequence, small clefts are formed in the cardiac muscle leading to blood leakage into the pericardial cavity and an arrest of heart function. The defects in the BM separating the brain from the adjacent mesenchyme caused invasion of brain tissue into the overlaying ectoderm leading to abnormal expansion of neuroepithelium, neuronal ectopias, and exencephaly. Finally, homozygotes developed a severe defect in cartilage, a tissue that lacks BMs. The chondrodysplasia is characterized by a reduction of the fibrillar collagen network, shortened collagen fibers, and elevated expression of cartilage extracellular matrix genes, suggesting that perlecan protects cartilage extracellular matrix from degradation. (+info)The putative tumor suppressors EXT1 and EXT2 form a stable complex that accumulates in the Golgi apparatus and catalyzes the synthesis of heparan sulfate. (4/110)
Hereditary multiple exostoses, a dominantly inherited genetic disorder characterized by multiple cartilaginous tumors, is caused by mutations in members of the EXT gene family, EXT1 or EXT2. The proteins encoded by these genes, EXT1 and EXT2, are endoplasmic reticulum-localized type II transmembrane glycoproteins that possess or are tightly associated with glycosyltransferase activities involved in the polymerization of heparan sulfate. Here, by testing a cell line with a specific defect in EXT1 in in vivo and in vitro assays, we show that EXT2 does not harbor significant glycosyltransferase activity in the absence of EXT1. Instead, it appears that EXT1 and EXT2 form a hetero-oligomeric complex in vivo that leads to the accumulation of both proteins in the Golgi apparatus. Remarkably, the Golgi-localized EXT1/EXT2 complex possesses substantially higher glycosyltransferase activity than EXT1 or EXT2 alone, which suggests that the complex represents the biologically relevant form of the enzyme(s). These findings provide a rationale to explain how inherited mutations in either of the two EXT genes can cause loss of activity, resulting in hereditary multiple exostoses. (+info)Vascular complications of osteochondromas. (5/110)
PURPOSE: Osteochondromas are the most common benign tumor of the bone. They are sometimes responsible for vascular complications involving either veins or arteries, principally around the knee. METHODS: We report six cases of such complications. An extensive review of literature through a computerized research was performed. RESULTS: We found 97 cases that were previously reported in the English literature giving sufficient details and providing data on 103 cases for analysis. CONCLUSION: Surgical treatment of vascular complications of osteochondromas is recommended as an urgent procedure to avoid irreversible damages, such as arterial occlusion, embolism, or phlebitis. Prophylactic resection of osteochondromas in the vicinity of a vessel must be performed. (+info)Comparison of fluorescent single-strand conformation polymorphism analysis and denaturing high-performance liquid chromatography for detection of EXT1 and EXT2 mutations in hereditary multiple exostoses. (6/110)
EXT1 and EXT2 are two genes responsible for the majority of cases of hereditary multiple exostoses (HME), a dominantly inherited bone disorder. In order to develop an efficient screening strategy for mutations in these genes, we performed two independent blind screens of EXT1 and EXT2 in 34 unrelated patients with HME, using denaturing high-performance liquid chromatography (DHPLC) and fluorescent single-strand conformation polymorphism analysis (F-SSCP). The mutation likely to cause HME was found in 29 (85%) of the 34 probands: in 22 of these (76%), the mutation was in EXT1; seven patients (24%) had EXT2 mutations. Nineteen of these disease mutations have not been previously reported. Of the 42 different amplicon variants identified in total in the cohort, 40 were detected by DHPLC and 39 by F-SSCP. This corresponds to mutation detection efficiencies of 95% and 93% respectively. We have also found that we can confidently distinguish between different sequence variants in the same fragment using F-SSCP but not DHPLC. In light of this, and the similarly high sensitivities of the two techniques, we propose to continue screening with F-SSCP. (+info)Chondrosarcoma in a family with multiple hereditary exostoses. (7/110)
Multiple hereditary exostoses is an autosomal dominant skeletal disorder in which there are numerous cartilage-capped excrescences in areas of actively growing bone. The condition is genetically heterogeneous, and at least three genes, ext1, ext2 and ext3 are involved. The reported risk for malignant transformation to chondrosarcoma has been from 0.6% to 2.8%. We have reviewed six generations of a family with 114 living adult members, 46 of them with multiple exostoses. Four have had operations for chondrosarcoma, giving the risk for malignant transformation as 8.3% in this family. Clinical and radiological examination revealed two additional patients with a suspicion of malignancy, but in whom the histological findings were benign. Reported elsewhere in detail, genetic linkage analysis mapped the causative gene to chromosome 11 and molecular studies revealed a guanine-to-thymine transversion in the ext2 gene. Patients with multiple hereditary exostoses carry a relatively high risk of malignant transformation. They should be informed of this possibility and regularly reviewed. (+info)Acetabular dysplasia associated with hereditary multiple exostoses. A case report. (8/110)
Hereditary multiple exostoses is an autosomal dominant disorder characterised by multiple osteochondromata, most commonly affecting the forearm, knee and ankle. Osteochondromata of the proximal femur have been reported to occur in 30% to 90% of affected patients with coxa valga in 25%. Acetabular dysplasia is rare but has been described. This is the first report of a patient requiring surgical intervention. A girl was seen at the age of nine with hereditary multiple exostoses and when 12 developed bilateral pain in the groin. Radiographs showed severely dysplastic acetabula with less than 50% coverage of the femoral heads and widening of the medial joint space. Large sessile osteochondromata were present along the medial side of the femoral neck proximal to the lesser trochanter, with associated coxa valga. The case illustrates the importance of obtaining initial skeletal surveys in children with hereditary multiple exostoses to identify potential problems such as acetabular dysplasia and subluxation of the hip. (+info)Exostoses are benign (noncancerous) bone growths that develop on the surface of a bone, usually in response to repeated stress or friction. They are often small and smooth, but can become larger and more irregular over time. In some cases, they may cause pain or discomfort, especially if they continue to grow and put pressure on nearby nerves, muscles, or other bones.
Exostoses can occur in various parts of the body, but they are most commonly found in the long bones of the arms and legs, as well as in the small bones of the feet. They may also develop in response to chronic irritation or injury, such as from jogging or playing sports that involve a lot of running or jumping.
In some cases, exostoses may be surgically removed if they cause persistent pain or other symptoms. However, in many cases, they do not require treatment and can be left alone. If you are concerned about any bone growths or other unusual symptoms, it is always best to consult with a healthcare professional for an accurate diagnosis and treatment plan.
Multiple hereditary exostoses (MHE) is a genetic condition characterized by the growth of multiple benign tumors known as osteochondromas. These tumors typically develop at the ends of long bones near the growth plates and can cause various skeletal deformities, limitations in mobility, and other health issues.
MHE is usually inherited in an autosomal dominant pattern, meaning that a child has a 50% chance of inheriting the condition if one parent has it. However, some cases may result from spontaneous mutations. The condition typically becomes apparent during childhood or adolescence and can affect both sexes equally.
The primary diagnostic feature of MHE is the presence of multiple osteochondromas, which are made up of bone and cartilage. These growths can cause a range of symptoms, including pain, swelling, decreased mobility, and an increased risk of fractures. In some cases, they may also lead to complications such as nerve compression or vascular damage.
Treatment for MHE typically involves surgical removal of the osteochondromas, particularly if they are causing significant symptoms or complications. Regular monitoring is also important to detect any new growths and assess their potential impact on health. In addition, physical therapy and other supportive measures may be recommended to help manage symptoms and maintain mobility.
Osteochondroma is a benign (noncancerous) bone tumor that typically develops during childhood or adolescent growth years. It usually forms near the end of long bones, such as those in the arms and legs, but can also occur in other bones. An osteochondroma may have a cartilage cap covering its surface.
This type of tumor often grows slowly and typically stops growing once the person has stopped growing. In many cases, an osteochondroma doesn't cause any symptoms and doesn't require treatment. However, if it continues to grow or causes problems such as pain, restricted movement, or bone deformity, surgical removal may be necessary.
Most osteochondromas are solitary (occurring singly), but some people can develop multiple tumors, a condition known as multiple hereditary exostoses or diaphyseal aclasis. This genetic disorder is associated with a higher risk of developing sarcoma, a type of cancerous tumor that can arise from osteochondromas.
It's essential to have regular follow-ups with your healthcare provider if you have an osteochondroma to monitor its growth and any potential complications.
N-Acetylglucosaminyltransferases (GlcNAc transferases) are a group of enzymes that play a crucial role in the post-translational modification of proteins by adding N-acetylglucosamine (GlcNAc) to specific amino acids in a protein sequence. These enzymes catalyze the transfer of GlcNAc from a donor molecule, typically UDP-GlcNAc, to acceptor proteins, which can be other glycoproteins or proteins without any prior glycosylation.
The addition of N-acetylglucosamine by these enzymes is an essential step in the formation of complex carbohydrate structures called N-linked glycans, which are attached to asparagine residues within the protein sequence. The process of adding GlcNAc can occur in different ways, leading to various types of N-glycan structures, such as oligomannose, hybrid, and complex types.
There are several classes of N-Acetylglucosaminyltransferases (GnTs) based on their substrate specificity and the type of glycosidic linkage they form:
1. GnT I (MGAT1): Transfers GlcNAc to the α1,6 position of the mannose residue in the chitobiose core of N-linked glycans, initiating the formation of complex-type structures.
2. GnT II (MGAT2): Adds a second GlcNAc residue to the β1,4 position of the mannose residue at the non-reducing end of the chitobiose core, forming bi-antennary N-glycans.
3. GnT III (MGAT3): Transfers GlcNAc to the β1,4 position of the mannose residue in the chitobiose core, creating a branching point for further glycosylation and leading to tri- or tetra-antennary N-glycans.
4. GnT IV (MGAT4): Adds GlcNAc to the β1,4 position of the mannose residue at the non-reducing end of antennae, forming multi-branched complex-type structures.
5. GnT V (MGAT5): Transfers GlcNAc to the β1,6 position of the mannose residue in the chitobiose core, leading to hybrid and complex-type N-glycans with bisecting GlcNAc.
6. GnT VI (MGAT6): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
7. GnT VII (MGAT7): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
8. GnT VIII (MGAT8): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
9. GnT IX (MGAT9): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
10. GnT X (MGAT10): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
11. GnT XI (MGAT11): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
12. GnT XII (MGAT12): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
13. GnT XIII (MGAT13): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
14. GnT XIV (MGAT14): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
15. GnT XV (MGAT15): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
16. GnT XVI (MGAT16): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
17. GnT XVII (MGAT17): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
18. GnT XVIII (MGAT18): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
19. GnT XIX (MGAT19): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
20. GnT XX (MGAT20): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
21. GnT XXI (MGAT21): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
22. GnT XXII (MGAT22): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
23. GnT XXIII (MGAT23): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
24. GnT XXIV (MGAT24): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
25. GnT XXV (MGAT25): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
26. GnT XXVI (MGAT26): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
27. GnT XXVII (MGAT27): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
28. GnT XXVIII (MGAT28): Adds GlcNAc to the α1,3 position of the mannose residue at the non-reducing end of antennae, forming a-linked poly-N-acetyllactosamine structures.
29. GnT XXIX (MGAT29): Transfers GlcNAc to the β1,6 position of the N-acetylglucosamine residue in complex-type N-glycans, forming i-antigen structures.
30. GnT XXX (MG
Osteochondromatosis is a benign (non-cancerous) condition where bone and cartilage grow outside the ends of bones, forming growths known as osteochondromas. These growths typically occur in areas where bones are growing actively, such as near the joints.
Osteochondromatosis can be hereditary or may develop sporadically. The hereditary form is called hereditary multiple exostoses (HME) or multiple osteochondromas, and it affects several bones in the body. In contrast, the sporadic form typically affects only one bone or a small number of bones.
Osteochondromatosis can cause various symptoms depending on the location and size of the growths. Some people with this condition may not experience any symptoms at all. However, if the osteochondromas grow near joints, they can cause pain, stiffness, or limited mobility. In some cases, the growths may also compress nerves or blood vessels, leading to additional complications such as numbness, tingling, or weakness in the affected limbs.
It is important to note that while osteochondromatosis itself is not cancerous, there is a small risk that the osteochondromas may undergo malignant transformation and develop into chondrosarcoma, a type of bone cancer. Regular follow-up with an orthopedic specialist is recommended to monitor any changes in the growths over time.
Chondrosarcoma is a type of cancer that develops in the cartilaginous tissue, which is the flexible and smooth connective tissue found in various parts of the body such as the bones, ribs, and nose. It is characterized by the production of malignant cartilage cells that can invade surrounding tissues and spread to other parts of the body (metastasis).
Chondrosarcomas are typically slow-growing tumors but can be aggressive in some cases. They usually occur in adults over the age of 40, and men are more commonly affected than women. The most common sites for chondrosarcoma development include the bones of the pelvis, legs, and arms.
Treatment for chondrosarcoma typically involves surgical removal of the tumor, along with radiation therapy or chemotherapy in some cases. The prognosis for chondrosarcoma depends on several factors, including the size and location of the tumor, the grade of malignancy, and whether it has spread to other parts of the body.
In medical terms, ribs are the long, curved bones that make up the ribcage in the human body. They articulate with the thoracic vertebrae posteriorly and connect to the sternum anteriorly via costal cartilages. There are 12 pairs of ribs in total, and they play a crucial role in protecting the lungs and heart, allowing room for expansion and contraction during breathing. Ribs also provide attachment points for various muscles involved in respiration and posture.
Nail diseases, also known as onychopathies, refer to a group of medical conditions that affect the nail unit, which includes the nail plate, nail bed, lunula, and surrounding skin (nail fold). These diseases can be caused by various factors such as fungal infections, bacterial infections, viral infections, systemic diseases, trauma, and neoplasms.
Some common examples of nail diseases include:
1. Onychomycosis - a fungal infection that affects the nail plate and bed, causing discoloration, thickening, and crumbling of the nail.
2. Paronychia - an infection or inflammation of the nail fold, caused by bacteria or fungi, resulting in redness, swelling, and pain.
3. Ingrown toenails - a condition where the nail plate grows into the surrounding skin, causing pain, redness, and infection.
4. Onycholysis - a separation of the nail plate from the nail bed, often caused by trauma or underlying medical conditions.
5. Psoriasis - a systemic disease that can affect the nails, causing pitting, ridging, discoloration, and onycholysis.
6. Lichen planus - an inflammatory condition that can affect the skin and nails, causing nail thinning, ridging, and loss.
7. Melanonychia - a darkening of the nail plate due to pigmentation, which can be benign or malignant.
8. Brittle nails - a condition characterized by weak, thin, and fragile nails that easily break or split.
9. Subungual hematoma - a collection of blood under the nail plate, often caused by trauma, resulting in discoloration and pain.
10. Tumors - abnormal growths that can develop in or around the nail unit, ranging from benign to malignant.
Accurate diagnosis and treatment of nail diseases require a thorough examination and sometimes laboratory tests, such as fungal cultures or skin biopsies. Treatment options vary depending on the underlying cause and may include topical or oral medications, surgical intervention, or lifestyle modifications.
The parietal bone is one of the four flat bones that form the skull's cranial vault, which protects the brain. There are two parietal bones in the skull, one on each side, located posterior to the frontal bone and temporal bone, and anterior to the occipital bone. Each parietal bone has a squamous part, which forms the roof and sides of the skull, and a smaller, wing-like portion called the mastoid process. The parietal bones contribute to the formation of the coronal and lambdoid sutures, which are fibrous joints that connect the bones in the skull.
Osteopoikilosis is a rare, benign skeletal dysplasia characterized by multiple small, dense spots of sclerotic bone (osteosclerosis) in the spongy part (trabecular) of the bones. These spots are most commonly found in the short tubular bones of the hands and feet, as well as the long bones such as the femur and tibia. The condition is usually asymptomatic and discovered incidentally on X-ray or CT scan. It is typically present at birth or appears in early childhood, and it affects both sexes equally. Osteopoikilosis can be associated with other bone disorders, such as melorheostosis and Buschke-Ollendorff syndrome.
Langer-Giedion Syndrome, also known as Trichorhinophalangeal Syndrome Type II (TRPSII), is a rare genetic disorder characterized by the presence of multiple exostoses (bony growths) and various distinctive facial features. It is caused by a deletion or mutation in the NIPBL gene, which is involved in regulating the activity of other genes during development.
The symptoms of Langer-Giedion Syndrome can include:
* Multiple exostoses (bony growths) on the long bones and ribs
* A prominent forehead (frontal bossing)
* Widely spaced eyes (hypertelorism)
* A broad and flat nasal bridge
* A long, thin nose with a bulbous tip
* Small, low-set ears
* A small jaw (micrognathia)
* Dental abnormalities
* Developmental delay or intellectual disability
* Skeletal abnormalities such as scoliosis and short stature
* Skin abnormalities such as thin skin on the hands and feet, and increased vulnerability to bruising.
It is important to note that this syndrome is very rare, with only a few hundred cases reported worldwide. The diagnosis of Langer-Giedion Syndrome is typically made based on clinical examination, medical history, and genetic testing. Management of the condition typically involves a multidisciplinary team of specialists including orthopedic surgeons, dental specialists, and geneticists to address the various symptoms and complications associated with the syndrome.
A transplant donor site refers to the area or location on a person's body where organs, tissues, or cells are removed during an organ, tissue, or cell transplantation procedure. The donor site can vary depending on the type of transplant being performed.
For example, in the case of an autologous bone marrow transplant, the donor site is typically the patient's own hip bones, where a portion of the marrow is extracted using a special needle. In a kidney or liver transplant, the donor site would be the abdomen, where the organ is removed from the living or deceased donor.
It is important to note that in order to minimize any potential complications or risks to the donor, the selection of the donor site is carefully planned and executed by trained medical professionals.
"Hallux" is a medical term that refers to the big toe or great toe, which is the first digit of the human foot. It is derived from Latin, where "hallus" means "big toe." In some contexts, specific pathologies or conditions related to the big toe may also be referred to as hallux issues, such as hallux valgus (a common foot deformity where the big toe drifts toward the second toe) or hallux rigidus (a form of degenerative arthritis that affects the big toe joint).
N-Acetylhexosaminyltransferases (also known as N-acetylglucosaminyltransferases) are a group of enzymes that play a role in the biosynthesis of glycoproteins and glycolipids. These enzymes catalyze the transfer of an N-acetylhexosamine (GlcNAc) residue from a donor molecule, typically a sugar nucleotide such as UDP-GlcNAc, to an acceptor molecule, which can be another sugar or a protein.
There are several different types of N-Acetylhexosaminyltransferases that have been identified, each with their own specific function and substrate specificity. These enzymes play important roles in various biological processes, including cell recognition, signaling, and adhesion. Dysregulation of these enzymes has been implicated in a number of diseases, including cancer and inflammatory disorders.
It's worth noting that the exact medical definition of N-Acetylhexosaminyltransferases may vary depending on the context and the specific type of enzyme being referred to.
Human chromosome pair 8 consists of two rod-shaped structures present in the nucleus of each cell of the human body. Each chromosome is made up of DNA tightly coiled around histone proteins, forming a complex structure known as a chromatin.
Human cells have 23 pairs of chromosomes, for a total of 46 chromosomes. Pair 8 is one of the autosomal pairs, meaning that it is not a sex chromosome (X or Y). Each member of chromosome pair 8 has a similar size, shape, and banding pattern, and they are identical in males and females.
Chromosome pair 8 contains several genes that are essential for various cellular functions and human development. Some of the genes located on chromosome pair 8 include those involved in the regulation of metabolism, nerve function, immune response, and cell growth and division.
Abnormalities in chromosome pair 8 can lead to genetic disorders such as Wolf-Hirschhorn syndrome, which is caused by a partial deletion of the short arm of chromosome 4, or partial trisomy 8, which results from an extra copy of all or part of chromosome 8. Both of these conditions are associated with developmental delays, intellectual disability, and various physical abnormalities.
Human chromosome pair 11 consists of two rod-shaped structures present in the nucleus of each cell in the human body. Each member of the pair is a single chromosome, and together they contain the genetic material that is inherited from both parents. They are located on the eleventh position in the standard karyotype, which is a visual representation of the 23 pairs of human chromosomes.
Chromosome 11 is one of the largest human chromosomes and contains an estimated 135 million base pairs. It contains approximately 1,400 genes that provide instructions for making proteins, as well as many non-coding RNA molecules that play a role in regulating gene expression.
Chromosome 11 is known to contain several important genes and genetic regions associated with various human diseases and conditions. For example, it contains the Wilms' tumor 1 (WT1) gene, which is associated with kidney cancer in children, and the neurofibromatosis type 1 (NF1) gene, which is associated with a genetic disorder that causes benign tumors to grow on nerves throughout the body. Additionally, chromosome 11 contains the region where the ABO blood group genes are located, which determine a person's blood type.
It's worth noting that human chromosomes come in pairs because they contain two copies of each gene, one inherited from the mother and one from the father. This redundancy allows for genetic diversity and provides a backup copy of essential genes, ensuring their proper function and maintaining the stability of the genome.
Heparin sulfate is not exactly referred to as "heparitin sulfate" in medical terminology. The correct term is heparan sulfate, which is a type of glycosaminoglycan (GAG), a long unbranched chain of repeating disaccharide units composed of a hexuronic acid and a hexosamine.
Heparan sulfate is found on the cell surface and in the extracellular matrix, where it plays crucial roles in various biological processes, including cell signaling, regulation of growth factor activity, and control of blood coagulation. It is also an important component of the proteoglycans, which are complex molecules that help to maintain the structural integrity and function of tissues and organs.
Like heparin, heparan sulfate has a high negative charge due to the presence of sulfate groups, which allows it to bind to and interact with various proteins and growth factors. However, heparan sulfate has a more diverse structure than heparin, with variations in the pattern of sulfation along the chain, which leads to specificity in its interactions with different proteins.
Defects in heparan sulfate biosynthesis or function have been implicated in various human diseases, including certain forms of cancer, developmental disorders, and infectious diseases.
Hemothorax is a medical condition characterized by the presence of blood in the pleural space, which is the area between the lungs and the chest wall. This accumulation of blood can occur due to various reasons such as trauma, rupture of a blood vessel, or complications from lung or heart surgery.
The buildup of blood in the pleural space can cause the affected lung to collapse, leading to symptoms such as shortness of breath, chest pain, and cough. In severe cases, hemothorax can be life-threatening if not promptly diagnosed and treated. Treatment options may include chest tube drainage, blood transfusion, or surgery, depending on the severity and underlying cause of the condition.
Periostitis is a medical condition characterized by inflammation of the periosteum, which is the highly vascularized tissue that covers the outer surface of bones. The periosteum contains nerves and blood vessels that supply the bone and assist in bone repair and remodeling. Periostitis can occur as a result of various factors such as repetitive trauma, infection, or inflammatory diseases, leading to pain, swelling, and tenderness in the affected area. In some cases, periostitis may also lead to the formation of new bone tissue, resulting in bony outgrowths known as exostoses.
The ulna is one of the two long bones in the forearm, the other being the radius. It runs from the elbow to the wrist and is located on the medial side of the forearm, next to the bone called the humerus in the upper arm. The ulna plays a crucial role in the movement of the forearm and also serves as an attachment site for various muscles.
Bone neoplasms are abnormal growths or tumors that develop in the bone. They can be benign (non-cancerous) or malignant (cancerous). Benign bone neoplasms do not spread to other parts of the body and are rarely a threat to life, although they may cause problems if they grow large enough to press on surrounding tissues or cause fractures. Malignant bone neoplasms, on the other hand, can invade and destroy nearby tissue and may spread (metastasize) to other parts of the body.
There are many different types of bone neoplasms, including:
1. Osteochondroma - a benign tumor that develops from cartilage and bone
2. Enchondroma - a benign tumor that forms in the cartilage that lines the inside of the bones
3. Chondrosarcoma - a malignant tumor that develops from cartilage
4. Osteosarcoma - a malignant tumor that develops from bone cells
5. Ewing sarcoma - a malignant tumor that develops in the bones or soft tissues around the bones
6. Giant cell tumor of bone - a benign or occasionally malignant tumor that develops from bone tissue
7. Fibrosarcoma - a malignant tumor that develops from fibrous tissue in the bone
The symptoms of bone neoplasms vary depending on the type, size, and location of the tumor. They may include pain, swelling, stiffness, fractures, or limited mobility. Treatment options depend on the type and stage of the tumor but may include surgery, radiation therapy, chemotherapy, or a combination of these treatments.
Human chromosome pair 19 refers to a group of 19 identical chromosomes that are present in every cell of the human body, except for the sperm and egg cells which contain only 23 chromosomes. Chromosomes are thread-like structures that carry genetic information in the form of DNA (deoxyribonucleic acid) molecules.
Each chromosome is made up of two arms, a shorter p arm and a longer q arm, separated by a centromere. Human chromosome pair 19 is an acrocentric chromosome, which means that the centromere is located very close to the end of the short arm (p arm).
Chromosome pair 19 contains approximately 58 million base pairs of DNA and encodes for around 1,400 genes. It is one of the most gene-dense chromosomes in the human genome, with many genes involved in important biological processes such as metabolism, immunity, and neurological function.
Abnormalities in chromosome pair 19 have been associated with various genetic disorders, including Sotos syndrome, which is characterized by overgrowth, developmental delay, and distinctive facial features, and Smith-Magenis syndrome, which is marked by intellectual disability, behavioral problems, and distinct physical features.