Thalassemia
alpha-Thalassemia
alpha-Globins
Globins
Hemoglobinopathies
Hemoglobins, Abnormal
Fetal Hemoglobin
beta-Thalassemia
Reticulocytes
Hemoglobin E
Chelation Therapy
Iron Overload
Iron Chelating Agents
Hemoglobin A2
Blood Transfusion
Deferoxamine
beta-Globins
Anemia, Sickle Cell
alpha 1-Antitrypsin
Hemoglobin H
Sicily
Hemoglobin J
Iron
Erythrocytes, Abnormal
Receptors, Adrenergic, alpha
Ferritins
Heterozygote
Hemoglobins
Hypoxia-Inducible Factor 1, alpha Subunit
Hemoglobin A
Erythrocyte Indices
Hemosiderosis
Base Sequence
delta-Thalassemia
Erythropoiesis
alpha7 Nicotinic Acetylcholine Receptor
Hemoglobin, Sickle
Erythrocytes
Mutation
Integrin alpha3beta1
A complex haemoglobinopathy diagnosis in a family with both beta zero- and alpha (zero/+)-thalassaemia homozygosity. (1/248)
The occurrence of point mutation alpha-thalassaemia and of complex combinations of haemoglobin defects is underestimated. Haemoglobinopathies, the most frequent monogenic recessive autosomal disorder in man, occur predominantly in Mediterranean, African and Asiatic populations. However, countries of immigration with a low incidence in the indigenous population, are now confronted with a highly heterogeneous array of imported defects. Furthermore, the occurrence of severe phenotypes is bound to increase in the near future because of the endogamous growth of the ethnical minorities and the lack of prevention. We describe an Afghan family in which both partners of a consanguineous relationship are carriers of a beta- as well as an alpha-thalassaemia determinant. The combination of defects was revealed by the in vitro measurement of the beta/alpha biosynthetic ratio and was characterised at the DNA level. The molecular defects involved are the Cd5(-CT), a Mediterranean beta zero-thalassaemia mutation, and the alpha 2(zero/+)-thalassaemia AATA(-AA) polyadenylation defect. The alpha-thalassemia defect is a rare RNA-processing mutant described only twice before in heterozygous form in Asian-Indian patients. The mutation suppresses the expression of a alpha 2 gene and reduces the expression of the less efficient, 3' located alpha 1 gene as well, inducing a near alpha zero-thalassaemia phenotype. This defect is now described for the first time in the homozygous condition in one of the children who, in addition to being homozygous for the alpha-thalassaemia point mutation, is also a carrier of the beta zero-thalassaemia defect. A previously described homozygous case of the alpha (zero/+)-thalassaemia condition, caused by a similar polyadenylation defect, was characterised by a severe HbH disease. However, the patient described here present at 7 years of age with severe caries, like his beta-thalassaemia homozygous brother but without hepatosplenomegaly, haemolysis or severe anaemia. The haematological analysis revealed 9.5 g/dl Hb; 5.4 x 10(12)/I RBC; 0.33 I/I PCV; 61 fl MCV; 17.6 pg MCH and 6.2% of HbA2. The biosynthetic ratio beta:alpha was 1.6 and no HbH fraction was detectable either on electrophoresis or as inclusion bodies. The parents reported no complications during pregnancy, at birth, or in the neonatal period in rural Afghanistan. We presume therefore that the counterbalancing effect induced by the co-existing beta-thalassaemia defect could have modified a potentially severe perinatal HbH disease into a strongly hypochromic but well compensated 'alpha zero-like heterozygous' thalassaemia phenotype. The risk of a severe HbH disease, could have been easily missed in this family which was referred because of a child affected with beta-thalassaemia major. (+info)Cardiac blood flow studies in fetuses with homozygous alpha-thalassemia-1 at 12-13 weeks of gestation. (2/248)
OBJECTIVE: Fetuses affected by homozygous alpha-thalassemia-1 develop anemia as early as the first trimester. Our objective was to study hemodynamic indices in affected fetuses at 12-13 weeks of gestation to determine whether these would be useful in the prediction of anemia. DESIGN: Prospective observational study. SUBJECTS: Women referred before 14 weeks of gestation for the prenatal diagnosis of homozygous alpha-thalassemia-1. METHODS: Transabdominal and/or transvaginal Doppler sonography was performed to measure the flow velocities in the fetal ascending aorta and pulmonary artery at 12-13 weeks. The Doppler indices were compared between those that were subsequently confirmed to be affected by homozygous alpha-thalassemia-1 and those that were unaffected. RESULTS: Between June 1997 and April 1998, 60 eligible women were recruited. Doppler examination was successful in 58 fetuses. Of these, 22 were subsequently confirmed to be affected by homozygous alpha-thalassemia-1. The diagnosis was made by chorionic villus sampling and DNA analysis in two affected fetuses and by cordocentesis and hemoglobin evaluation in 20 affected fetuses. Hemoglobin concentrations could be measured in ten fetuses and these ranged from 4 to 8 g/dl. The affected fetuses had significantly higher peak velocities at the pulmonary valve and ascending aorta and a larger inner diameter of the pulmonary valve than that in unaffected fetuses. The total cardiac output was increased by one-third in affected fetuses and was mainly due to an increase of the right-side cardiac output. CONCLUSION: In the early stage of anemia, the fetus responds mainly by increasing its right-side cardiac output. However, there is extensive overlap of the values of cardiac output between the affected and the unaffected fetuses, precluding its use in the prediction of anemia. (+info)Evaluation of a mutation screening strategy for sporadic cases of ATR-X syndrome. (3/248)
We report on the evaluation of a strategy for screening for XNP/ATR-X mutations in males with mental retardation and associated dysmorphology. Because nearly half of the mutations in this gene reported to date fall into a short 300 bp region of the transcript, we decided to focus in this region and to extend the mutation analysis to cases with a negative family history. This study includes 21 mentally retarded male patients selected because they had severe mental retardation and a typical facial appearance. The presence of haemoglobin H or urogenital abnormalities was not considered critical for inclusion in this study. We have identified six mutations which represents a mutation detection rate of 28%. This figure is high enough for us to propose this strategy as a valid first level of screening in a selected subset of males with mental retardation. This approach is simple, does not require RNA preparation, does not involve time consuming mutation detection methods, and can thus be applied to a large number of patients at a low cost in any given laboratory. (+info)Intrathoracic extramedullary haematopoiesis complicated by massive haemothorax in alpha-thalassaemia. (4/248)
Intrathoracic extramedullary haematopoiesis (EMH) is a rare entity that is usually asymptomatic. A 44 year old man with alpha-thalassaemia is described who developed dyspnoea and massive left sided haemothorax. The haemoglobin disorder was established by Hgb H staining and haemoglobin electrophoretic studies. The DNA analysis revealed it to be a case of double heterozygous terminal codon mutation with the genotype alphaalphaCS/alphaalphaT. Computed tomographic scanning and magnetic resonance imaging of the thorax showed multiple paravertebral masses which were found by thoracoscopic biopsy to be extramedullary haematopoiesis. Although no additional sclerosing pleurodesis or low dose radiation therapy was given, the lung expanded well and there has been no recurrence of haemothorax to date. (+info)Impairment of Plasmodium falciparum growth in thalassemic red blood cells: further evidence by using biotin labeling and flow cytometry. (5/248)
Certain red blood cell (RBC) disorders, including thalassemia, have been associated with an innate protection against malaria infection. However, many in vitro correlative studies have been inconclusive. To better understand the relationship between human RBCs with thalassemia hemoglobinopathies and susceptibility to in vitro infection, we used an in vitro coculture system that involved biotin labeling and flow cytometry to study the ability of normal and variant RBC populations in supporting the growth of Plasmodium falciparum malaria parasites. Results showed that both normal and thalassemic RBCs were susceptible to P falciparum invasion, but the parasite multiplication rates were significantly reduced in the thalassemic RBC populations. The growth inhibition was especially marked in RBCs from alpha-thalassemia patients (both alpha-thalassemia1/alpha-thalassemia2 and alpha-thalassemia1 heterozygote). Our observations support the contention that thalassemia confers protection against malaria and may explain why it is more prevalent in malaria endemic areas. (+info)The contribution of alpha+-thalassaemia to anaemia in a Nigerian population exposed to intense malaria transmission. (6/248)
The proportion to which alpha-thalassaemia contributes to anaemia in Africa is not well recognized. In an area of intense malaria transmission in South-West Nigeria, haematological parameters of alpha-thalassaemia were examined in 494 children and 119 adults. The -alpha3.7 type of alpha+-thalassaemia was observed at a gene frequency of 0.27. Nine and 36.5% of individuals were homozygous and heterozygous, respectively. P.falciparum-infection was present in 78% of children and in 39% of adults. The alpha-globin genotypes did not correlate with the prevalence of P. falciparum-infection. alpha+-thalassaemic individuals had significantly lower mean values of haemoglobin, mean corpuscular volume, and mean corpuscular haemoglobin than non-thalassaemic subjects. Anaemia was seen in 54. 7% of children with a normal alpha-globin genotype, in 69.9% of heterozygous (odds ratio: 1.99, 95% confidence interval: 1.32-3.00, P = 0.001), and in 88.4% of homozygous alpha+-thalassaemic children (odds ratio: 7.72, 95% confidence interval: 2.85-20.90, P = 0.0001). The findings show that alpha+-thalassaemia contributes essentially to mild anaemia, microcytosis, and hypochromia in Nigeria. (+info)A normal beta-globin allele as a modifier gene ameliorating the severity of alpha-thalassemia in mice. (7/248)
Thalassemia is a heritable human anemia caused by a variety of mutations that affect expression of the alpha- or the beta-chain of hemoglobin. The expressivity of the phenotype is likely to be influenced by unlinked modifying genes. Indeed, by using a mouse model of alpha-thalassemia, we find that its phenotype is strongly influenced by the genetic background in which the alpha-thalassemia mutation resides [129(sv/ev)/129(sv/ev) (severe) or 129(sv/ev)/C57BL/6 (mild)]. Linkage mapping indicates that the modifying gene is very tightly linked to the beta-globin locus (Lod score = 13.3). Furthermore, the severity of the phenotype correlates with the size of beta-chain-containing inclusion bodies that accumulate in red blood cells and likely accelerate their destruction. The beta-major globin chains encoded by the two strains differ by three amino acids, one of which is a glycine-to-cysteine substitution at position 13. The Cys-13 should be available for interchain disulfide bridging and consequent aggregation between excess beta-chains. This normal polymorphic variation between murine beta-globin chains could account for the modifying action of the unlinked beta-globin locus. Here, the variation in severity of the phenotype would not depend on a change in the ratio between alpha- and beta-chains but on the chemical nature of the normal beta-chain, which is in excess. This work also indicates that modifying genes can be normal variants that-absent an apparent physiologic rationale-may be difficult to identify on the basis of structure alone. (+info)Nuchal translucency in fetuses affected by homozygous alpha-thalassemia-1 at 12-13 weeks of gestation. (8/248)
OBJECTIVE: Fetuses affected by homozygous alpha-thalassemia-1 are anemic in the first trimester. We studied their nuchal translucency (NT) measurements at 12-13 weeks of gestation. METHODS: Nuchal translucency was measured prospectively in fetuses at risk of homozygous alpha-thalassemia-1. Measurements of those fetuses subsequently confirmed to be affected by homozygous alpha-thalassemia-1 but with a normal karyotype were compared to those of 440 controls. The controls were from the general obstetric population who had NT measurements at 12 or 13 weeks with known normal outcome. All the NT measurements were expressed as multiples of the median (MoM) for the gestational day. RESULTS: Between 1996 and 1998, 94 at-risk pregnancies were studied. Of these, 32 were subsequently confirmed to be affected by homozygous alpha-thalassemia-1. Chromosome study was not carried out in three cases and these were excluded from the analysis. Nuchal translucency MoMs for cases and controls were found to fit a log Gaussian distribution. The log means (standard deviation) for case and control NT MoM were 0.075 (0.156) and -0.0019 (0.091), respectively. The median NT MoM (95% CI) for cases was 1.19 (1.08-1.62) and was significantly higher than that of the controls (p < 0.001). However, there was extensive overlap of NT between cases and controls. CONCLUSION: Overall, there was a 19% increase in NT MoM in fetuses affected by homozygous alpha-thalassemia-1. This represents a difference of only 0.3-0.4 mm, which is clinically insignificant. This finding indirectly suggests that the increased NT in trisomic fetuses cannot be explained by fetal anemia. Conversely, the presence of increased NT in a fetus at risk of homozygous alpha-thalassemia-1 should alert one to the possibility of chromosomal abnormality rather than being attributed to fetal anemia. (+info)Thalassemia is a group of inherited genetic disorders that affect the production of hemoglobin, a protein in red blood cells responsible for carrying oxygen throughout the body. The disorder results in less efficient or abnormal hemoglobin, which can lead to anemia, an insufficient supply of oxygen-rich red blood cells.
There are two main types of Thalassemia: alpha and beta. Alpha thalassemia occurs when there is a problem with the alpha globin chain production, while beta thalassemia results from issues in beta globin chain synthesis. These disorders can range from mild to severe, depending on the number of genes affected and their specific mutations.
Severe forms of Thalassemia may require regular blood transfusions, iron chelation therapy, or even a bone marrow transplant to manage symptoms and prevent complications.
Alpha-thalassemia is a genetic disorder that affects the production of hemoglobin, a protein in red blood cells that carries oxygen throughout the body. It is caused by deletions or mutations in the genes that produce the alpha-globin chains of hemoglobin.
There are several types of alpha-thalassemia, ranging from mild to severe. The most severe form, called hydrops fetalis, occurs when all four alpha-globin genes are deleted or mutated. This can cause stillbirth or death shortly after birth due to heart failure and severe anemia.
Less severe forms of alpha-thalassemia can cause mild to moderate anemia, which may be asymptomatic or associated with symptoms such as fatigue, weakness, and jaundice. These forms of the disorder are more common in people from Mediterranean, Southeast Asian, and African backgrounds.
Treatment for alpha-thalassemia depends on the severity of the condition and may include blood transfusions, iron chelation therapy, or occasionally stem cell transplantation.
Alpha-globins are a type of globin protein that combine to form the alpha-globin chains of hemoglobin, the oxygen-carrying protein in red blood cells. Hemoglobin is composed of four globin chains, two alpha-globin chains and two beta-globin chains, that surround a heme group. The alpha-globin genes are located on chromosome 16 and are essential for normal hemoglobin function. Mutations in the alpha-globin genes can lead to various forms of hemoglobin disorders such as alpha-thalassemia.
Globins are a group of proteins that contain a heme prosthetic group, which binds and transports oxygen in the blood. The most well-known globin is hemoglobin, which is found in red blood cells and is responsible for carrying oxygen from the lungs to the body's tissues. Other members of the globin family include myoglobin, which is found in muscle tissue and stores oxygen, and neuroglobin and cytoglobin, which are found in the brain and other organs and may have roles in protecting against oxidative stress and hypoxia (low oxygen levels). Globins share a similar structure, with a folded protein surrounding a central heme group. Mutations in globin genes can lead to various diseases, such as sickle cell anemia and thalassemia.
Hemoglobinopathies are a group of genetic disorders characterized by structural or functional abnormalities of the hemoglobin molecule in red blood cells. Hemoglobin is a complex protein that plays a crucial role in carrying oxygen throughout the body. The two most common types of hemoglobinopathies are sickle cell disease and thalassemia.
In sickle cell disease, a single mutation in the beta-globin gene results in the production of an abnormal form of hemoglobin called hemoglobin S (HbS). When deoxygenated, HbS molecules tend to aggregate and form long polymers, causing the red blood cells to become sickle-shaped, rigid, and fragile. These abnormally shaped cells can block small blood vessels, leading to tissue damage, chronic pain, organ dysfunction, and other serious complications.
Thalassemias are a heterogeneous group of disorders caused by mutations in the genes that regulate the production of alpha- or beta-globin chains. These mutations result in reduced or absent synthesis of one or more globin chains, leading to an imbalance in hemoglobin composition and structure. This imbalance can cause premature destruction of red blood cells (hemolysis), resulting in anemia, jaundice, splenomegaly, and other symptoms.
Hemoglobinopathies are typically inherited in an autosomal recessive manner, meaning that affected individuals have two copies of the abnormal gene – one from each parent. Carriers of a single abnormal gene usually do not show any signs or symptoms of the disorder but can pass the abnormal gene on to their offspring.
Early diagnosis and appropriate management of hemoglobinopathies are essential for improving quality of life, reducing complications, and increasing survival rates. Treatment options may include blood transfusions, iron chelation therapy, antibiotics, pain management, and, in some cases, bone marrow transplantation or gene therapy.
Abnormal hemoglobins refer to variants of the oxygen-carrying protein found in red blood cells, which differ from the normal adult hemoglobin (HbA) in terms of their structure and function. These variations can result from genetic mutations that affect the composition of the globin chains in the hemoglobin molecule. Some abnormal hemoglobins are clinically insignificant, while others can lead to various medical conditions such as hemolytic anemia, thalassemia, or sickle cell disease. Examples of abnormal hemoglobins include HbS (associated with sickle cell anemia), HbC, HbE, and HbF (fetal hemoglobin). These variants can be detected through specialized laboratory tests, such as hemoglobin electrophoresis or high-performance liquid chromatography (HPLC).
Erythrocyte count, also known as red blood cell (RBC) count, is a laboratory test that measures the number of red blood cells in a sample of blood. Red blood cells are important because they carry oxygen from the lungs to the rest of the body. A low erythrocyte count may indicate anemia, while a high count may be a sign of certain medical conditions such as polycythemia. The normal range for erythrocyte count varies depending on a person's age, sex, and other factors.
Fetal hemoglobin (HbF) is a type of hemoglobin that is produced in the fetus and newborn babies. It is composed of two alpha-like globin chains and two gamma-globin chains, designated as α2γ2. HbF is the primary form of hemoglobin during fetal development, replacing the embryonic hemoglobin (HbG) around the eighth week of gestation.
The unique property of HbF is its higher affinity for oxygen compared to adult hemoglobin (HbA), which helps ensure adequate oxygen supply from the mother to the developing fetus. After birth, as the newborn starts breathing on its own and begins to receive oxygen directly, the production of HbF gradually decreases and is usually replaced by HbA within the first year of life.
In some genetic disorders like sickle cell disease and beta-thalassemia, persistence of HbF into adulthood can be beneficial as it reduces the severity of symptoms due to its higher oxygen-carrying capacity and less polymerization tendency compared to HbS (in sickle cell disease) or unpaired alpha chains (in beta-thalassemia). Treatments like hydroxyurea are used to induce HbF production in these patients as a therapeutic approach.
Beta-thalassemia is a genetic blood disorder that affects the production of hemoglobin, a protein in red blood cells that carries oxygen throughout the body. Specifically, beta-thalassemia is caused by mutations in the beta-globin gene, which leads to reduced or absent production of the beta-globin component of hemoglobin.
There are two main types of beta-thalassemia:
1. Beta-thalassemia major (also known as Cooley's anemia): This is a severe form of the disorder that typically becomes apparent in early childhood. It is characterized by a significant reduction or absence of beta-globin production, leading to anemia, enlarged spleen and liver, jaundice, and growth retardation.
2. Beta-thalassemia intermedia: This is a milder form of the disorder that may not become apparent until later in childhood or even adulthood. It is characterized by a variable reduction in beta-globin production, leading to mild to moderate anemia and other symptoms that can range from nonexistent to severe.
Treatment for beta-thalassemia depends on the severity of the disorder and may include blood transfusions, iron chelation therapy, and/or bone marrow transplantation. In some cases, genetic counseling and prenatal diagnosis may also be recommended for families with a history of the disorder.
Reticulocytes are immature red blood cells that still contain remnants of organelles, such as ribosomes and mitochondria, which are typically found in developing cells. These organelles are involved in the process of protein synthesis and energy production, respectively. Reticulocytes are released from the bone marrow into the bloodstream, where they continue to mature into fully developed red blood cells called erythrocytes.
Reticulocytes can be identified under a microscope by their staining characteristics, which reveal a network of fine filaments or granules known as the reticular apparatus. This apparatus is composed of residual ribosomal RNA and other proteins that have not yet been completely eliminated during the maturation process.
The percentage of reticulocytes in the blood can be used as a measure of bone marrow function and erythropoiesis, or red blood cell production. An increased reticulocyte count may indicate an appropriate response to blood loss, hemolysis, or other conditions that cause anemia, while a decreased count may suggest impaired bone marrow function or a deficiency in erythropoietin, the hormone responsible for stimulating red blood cell production.
Hemoglobin E (HbE) is a structural variant of hemoglobin, which is the oxygen-carrying protein in red blood cells. This variant results from a specific mutation in the beta-globin gene, leading to the substitution of glutamic acid with lysine at position 26 of the beta-globin chain.
HbE is most commonly found in people from Southeast Asia, particularly in populations from Thailand, Cambodia, and Laos. It can also be found in other parts of the world, such as India, Bangladesh, and Pakistan. HbE is usually asymptomatic when it occurs in its heterozygous form (one normal beta-globin gene and one HbE gene). However, when it occurs in the homozygous form (two HbE genes), or in combination with other hemoglobinopathies like thalassemia, it can lead to a range of clinical manifestations, including mild to severe microcytic anemia, splenomegaly, and jaundice.
Individuals with HbE may have increased susceptibility to certain infections and may experience complications during pregnancy or surgery due to impaired oxygen-carrying capacity. Regular monitoring of hemoglobin levels, iron status, and potential complications is essential for managing individuals with Hemoglobin E effectively.
Chelation therapy is a medical treatment that involves the use of chelating agents to remove heavy metals and minerals from the body. A chelating agent is a molecule that bonds with the metal ions, forming a stable, water-soluble complex that can be excreted through urine or stool.
The most common chelating agent used in medical settings is ethylene diamine tetraacetic acid (EDTA), which is administered intravenously. EDTA binds with metals such as lead, mercury, iron, and calcium, and helps to eliminate them from the body.
Chelation therapy is primarily used to treat heavy metal poisoning, such as lead or mercury toxicity. It may also be used in some cases to treat cardiovascular disease, although its effectiveness for this use is still a matter of debate and controversy.
It's important to note that chelation therapy should only be administered under the supervision of a qualified healthcare professional, as improper use can lead to serious side effects and complications.
Iron overload is a condition characterized by an excessive accumulation of iron in the body's tissues and organs, particularly in the liver, heart, and pancreas. This occurs when the body absorbs more iron than it can use or eliminate, leading to iron levels that are higher than normal.
Iron overload can result from various factors, including hereditary hemochromatosis, a genetic disorder that affects how the body absorbs iron from food; frequent blood transfusions, which can cause iron buildup in people with certain chronic diseases such as sickle cell anemia or thalassemia; and excessive consumption of iron supplements or iron-rich foods.
Symptoms of iron overload may include fatigue, joint pain, abdominal discomfort, irregular heartbeat, and liver dysfunction. If left untreated, it can lead to serious complications such as cirrhosis, liver failure, diabetes, heart problems, and even certain types of cancer. Treatment typically involves regular phlebotomy (removal of blood) to reduce iron levels in the body, along with dietary modifications and monitoring by a healthcare professional.
Iron chelating agents are medications that bind to iron in the body, forming a stable complex that can then be excreted from the body. These agents are primarily used to treat iron overload, a condition that can occur due to frequent blood transfusions or certain genetic disorders such as hemochromatosis. By reducing the amount of iron in the body, these medications can help prevent or reduce damage to organs such as the heart and liver. Examples of iron chelating agents include deferoxamine, deferasirox, and deferiprone.
Hemoglobin A2 is a type of hemoglobin that is found in human red blood cells. Hemoglobin is the protein in red blood cells that carries oxygen throughout the body. Hemoglobin A2 is made up of two alpha-like globin chains and two delta-globin chains, and it accounts for approximately 1.5 to 3.5% of the total hemoglobin in adult humans.
Hemoglobin A2 is not normally present in significant amounts until after a child has passed through their first year of life. Its level remains relatively constant throughout adulthood, and it is often used as a diagnostic marker for certain types of anemia, such as beta-thalassemia. In people with beta-thalassemia, the production of beta-globin chains is reduced or absent, leading to an increase in the relative proportion of Hemoglobin A2 and Hemoglobin F (fetal hemoglobin) in the red blood cells.
It's important to note that Hemoglobin A2 measurement alone is not enough for a definitive diagnosis of beta-thalassemia, but it can be used as a supportive test along with other investigations such as complete blood count (CBC), hemoglobin electrophoresis and molecular genetic testing.
A blood transfusion is a medical procedure in which blood or its components are transferred from one individual (donor) to another (recipient) through a vein. The donated blood can be fresh whole blood, packed red blood cells, platelets, plasma, or cryoprecipitate, depending on the recipient's needs. Blood transfusions are performed to replace lost blood due to severe bleeding, treat anemia, support patients undergoing major surgeries, or manage various medical conditions such as hemophilia, thalassemia, and leukemia. The donated blood must be carefully cross-matched with the recipient's blood type to minimize the risk of transfusion reactions.
Deferoxamine is a medication used to treat iron overload, which can occur due to various reasons such as frequent blood transfusions or excessive iron intake. It works by binding to excess iron in the body and promoting its excretion through urine. This helps to prevent damage to organs such as the heart and liver that can be caused by high levels of iron.
Deferoxamine is an injectable medication that is typically administered intravenously or subcutaneously, depending on the specific regimen prescribed by a healthcare professional. It may also be used in combination with other medications to manage iron overload more effectively.
It's important to note that deferoxamine should only be used under the guidance of a medical professional, as improper use or dosing can lead to serious side effects or complications.
Pyridones are a class of organic compounds that contain a pyridone ring, which is a heterocyclic ring consisting of a six-membered ring with five carbon atoms and one nitrogen atom, with one oxygen atom attached to the nitrogen atom by a double bond. Pyridones can be found in various natural sources, including plants and microorganisms, and they also have important applications in the pharmaceutical industry as building blocks for drug design and synthesis. Some drugs that contain pyridone rings include antihistamines, anti-inflammatory agents, and antiviral agents.
Beta-globins are the type of globin proteins that make up the beta-chain of hemoglobin, the oxygen-carrying protein in red blood cells. Hemoglobin is composed of four polypeptide chains, two alpha-globin and two beta-globin chains, arranged in a specific structure. The beta-globin gene is located on chromosome 11, and mutations in this gene can lead to various forms of hemoglobin disorders such as sickle cell anemia and beta-thalassemia.
Sickle cell anemia is a genetic disorder that affects the hemoglobin in red blood cells. Hemoglobin is responsible for carrying oxygen throughout the body. In sickle cell anemia, the hemoglobin is abnormal and causes the red blood cells to take on a sickle shape, rather than the normal disc shape. These sickled cells are stiff and sticky, and they can block blood vessels, causing tissue damage and pain. They also die more quickly than normal red blood cells, leading to anemia.
People with sickle cell anemia often experience fatigue, chronic pain, and jaundice. They may also have a higher risk of infections and complications such as stroke, acute chest syndrome, and priapism. The disease is inherited from both parents, who must both be carriers of the sickle cell gene. It primarily affects people of African descent, but it can also affect people from other ethnic backgrounds.
There is no cure for sickle cell anemia, but treatments such as blood transfusions, medications to manage pain and prevent complications, and bone marrow transplantation can help improve quality of life for affected individuals. Regular medical care and monitoring are essential for managing the disease effectively.
Alpha 1-antitrypsin (AAT, or α1-antiproteinase, A1AP) is a protein that is primarily produced by the liver and released into the bloodstream. It belongs to a group of proteins called serine protease inhibitors, which help regulate inflammation and protect tissues from damage caused by enzymes involved in the immune response.
Alpha 1-antitrypsin is particularly important for protecting the lungs from damage caused by neutrophil elastase, an enzyme released by white blood cells called neutrophils during inflammation. In the lungs, AAT binds to and inhibits neutrophil elastase, preventing it from degrading the extracellular matrix and damaging lung tissue.
Deficiency in alpha 1-antitrypsin can lead to chronic obstructive pulmonary disease (COPD) and liver disease. The most common cause of AAT deficiency is a genetic mutation that results in abnormal folding and accumulation of the protein within liver cells, leading to reduced levels of functional AAT in the bloodstream. This condition is called alpha 1-antitrypsin deficiency (AATD) and can be inherited in an autosomal codominant manner. Individuals with severe AATD may require augmentation therapy with intravenous infusions of purified human AAT to help prevent lung damage.
Hemoglobin H (Hb H) is a type of abnormal hemoglobin that can occur in individuals with certain genetic disorders, such as hemoglobinopathies. It is formed when four beta-globin chains come together, instead of the usual two alpha and two beta chains found in normal adult hemoglobin (Hb A).
This abnormal structure can result from a mutation that causes the absence or deficiency of alpha-globin chains, leading to an excess of beta-globin chains. Hemoglobin H is often associated with conditions such as thalassemia, particularly when there is a severe deficiency of alpha-globin chain production (alpha-thalassemia).
Hemoglobin H can cause hemolytic anemia, which means that the red blood cells are destroyed prematurely. The severity of the condition depends on the degree of imbalance between alpha and beta chains and other genetic factors. Symptoms may include fatigue, jaundice, and splenomegaly (enlarged spleen).
I'm sorry for any confusion, but "Sicily" is not a medical term. It is actually a large island located in the Mediterranean Sea, south of the Italian Peninsula, and it is one of the five autonomous regions of Italy. If you have any questions about medical terminology or health-related topics, I would be happy to help!
Hemoglobin J is a variant form of hemoglobin, which is the oxygen-carrying protein in red blood cells. This variant is caused by a specific mutation in the gene for the beta-globin chain, one of the two types of chains that make up hemoglobin.
The mutation responsible for Hemoglobin J results in the substitution of a glutamic acid residue with a valine residue at position 6 of the beta-globin chain. This change can lead to the formation of abnormal hemoglobin molecules that can cause red blood cells to become fragile and susceptible to rupture, a condition known as hemolysis.
Hemoglobin J is typically detected during routine newborn screening or through diagnostic testing for hemoglobin disorders. While Hemoglobin J itself is not considered a disease-causing variant, individuals who inherit it in combination with other abnormal hemoglobin genes may be at risk for developing hemolytic anemia or other related conditions.
In the context of medicine, iron is an essential micromineral and key component of various proteins and enzymes. It plays a crucial role in oxygen transport, DNA synthesis, and energy production within the body. Iron exists in two main forms: heme and non-heme. Heme iron is derived from hemoglobin and myoglobin in animal products, while non-heme iron comes from plant sources and supplements.
The recommended daily allowance (RDA) for iron varies depending on age, sex, and life stage:
* For men aged 19-50 years, the RDA is 8 mg/day
* For women aged 19-50 years, the RDA is 18 mg/day
* During pregnancy, the RDA increases to 27 mg/day
* During lactation, the RDA for breastfeeding mothers is 9 mg/day
Iron deficiency can lead to anemia, characterized by fatigue, weakness, and shortness of breath. Excessive iron intake may result in iron overload, causing damage to organs such as the liver and heart. Balanced iron levels are essential for maintaining optimal health.
A homozygote is an individual who has inherited the same allele (version of a gene) from both parents and therefore possesses two identical copies of that allele at a specific genetic locus. This can result in either having two dominant alleles (homozygous dominant) or two recessive alleles (homozygous recessive). In contrast, a heterozygote has inherited different alleles from each parent for a particular gene.
The term "homozygote" is used in genetics to describe the genetic makeup of an individual at a specific locus on their chromosomes. Homozygosity can play a significant role in determining an individual's phenotype (observable traits), as having two identical alleles can strengthen the expression of certain characteristics compared to having just one dominant and one recessive allele.
Abnormal erythrocytes refer to red blood cells that have an abnormal shape, size, or other characteristics. This can include various types of abnormalities such as:
1. Anisocytosis: Variation in the size of erythrocytes.
2. Poikilocytosis: Variation in the shape of erythrocytes, including but not limited to teardrop-shaped cells (dacrocytes), crescent-shaped cells (sickle cells), and spherical cells (spherocytes).
3. Anemia: A decrease in the total number of erythrocytes or a reduction in hemoglobin concentration, which can result from various underlying conditions such as iron deficiency, chronic disease, or blood loss.
4. Hemoglobinopathies: Abnormalities in the structure or function of hemoglobin, the protein responsible for carrying oxygen in erythrocytes, such as sickle cell anemia and thalassemia.
5. Inclusion bodies: Abnormal structures within erythrocytes, such as Heinz bodies (denatured hemoglobin) or Howell-Jolly bodies (nuclear remnants).
These abnormalities can be detected through a complete blood count (CBC) and peripheral blood smear examination. The presence of abnormal erythrocytes may indicate an underlying medical condition, and further evaluation is often necessary to determine the cause and appropriate treatment.
Adrenergic receptors are a type of G protein-coupled receptor that bind and respond to catecholamines, such as epinephrine (adrenaline) and norepinephrine (noradrenaline). Alpha adrenergic receptors (α-ARs) are a subtype of adrenergic receptors that are classified into two main categories: α1-ARs and α2-ARs.
The activation of α1-ARs leads to the activation of phospholipase C, which results in an increase in intracellular calcium levels and the activation of various signaling pathways that mediate diverse physiological responses such as vasoconstriction, smooth muscle contraction, and cell proliferation.
On the other hand, α2-ARs are primarily located on presynaptic nerve terminals where they function to inhibit the release of neurotransmitters, including norepinephrine. The activation of α2-ARs also leads to the inhibition of adenylyl cyclase and a decrease in intracellular cAMP levels, which can mediate various physiological responses such as sedation, analgesia, and hypotension.
Overall, α-ARs play important roles in regulating various physiological functions, including cardiovascular function, mood, and cognition, and are also involved in the pathophysiology of several diseases, such as hypertension, heart failure, and neurodegenerative disorders.
Sickle cell trait is a genetic condition where an individual inherits one abnormal gene for hemoglobin S (HbS) from one parent and one normal gene for hemoglobin A (HbA) from the other parent. Hemoglobin is a protein in red blood cells that carries oxygen throughout the body.
People with sickle cell trait do not have sickle cell disease, but they can pass the abnormal HbS gene on to their children. In certain situations, such as high altitude, low oxygen levels, or intense physical exertion, individuals with sickle cell trait may experience symptoms similar to those of sickle cell disease, such as fatigue, pain, and shortness of breath. However, these symptoms are typically milder and less frequent than in people with sickle cell disease.
It is important for individuals who know they have sickle cell trait to inform their healthcare providers, especially if they become pregnant or plan to engage in activities that may cause low oxygen levels, such as scuba diving or high-altitude climbing.
Ferritin is a protein in iron-metabolizing cells that stores iron in a water-soluble form. It is found inside the cells (intracellular) and is released into the bloodstream when the cells break down or die. Measuring the level of ferritin in the blood can help determine the amount of iron stored in the body. High levels of ferritin may indicate hemochromatosis, inflammation, liver disease, or other conditions. Low levels of ferritin may indicate anemia, iron deficiency, or other conditions.
A heterozygote is an individual who has inherited two different alleles (versions) of a particular gene, one from each parent. This means that the individual's genotype for that gene contains both a dominant and a recessive allele. The dominant allele will be expressed phenotypically (outwardly visible), while the recessive allele may or may not have any effect on the individual's observable traits, depending on the specific gene and its function. Heterozygotes are often represented as 'Aa', where 'A' is the dominant allele and 'a' is the recessive allele.
Hemoglobin (Hb or Hgb) is the main oxygen-carrying protein in the red blood cells, which are responsible for delivering oxygen throughout the body. It is a complex molecule made up of four globin proteins and four heme groups. Each heme group contains an iron atom that binds to one molecule of oxygen. Hemoglobin plays a crucial role in the transport of oxygen from the lungs to the body's tissues, and also helps to carry carbon dioxide back to the lungs for exhalation.
There are several types of hemoglobin present in the human body, including:
* Hemoglobin A (HbA): This is the most common type of hemoglobin, making up about 95-98% of total hemoglobin in adults. It consists of two alpha and two beta globin chains.
* Hemoglobin A2 (HbA2): This makes up about 1.5-3.5% of total hemoglobin in adults. It consists of two alpha and two delta globin chains.
* Hemoglobin F (HbF): This is the main type of hemoglobin present in fetal life, but it persists at low levels in adults. It consists of two alpha and two gamma globin chains.
* Hemoglobin S (HbS): This is an abnormal form of hemoglobin that can cause sickle cell disease when it occurs in the homozygous state (i.e., both copies of the gene are affected). It results from a single amino acid substitution in the beta globin chain.
* Hemoglobin C (HbC): This is another abnormal form of hemoglobin that can cause mild to moderate hemolytic anemia when it occurs in the homozygous state. It results from a different single amino acid substitution in the beta globin chain than HbS.
Abnormal forms of hemoglobin, such as HbS and HbC, can lead to various clinical disorders, including sickle cell disease, thalassemia, and other hemoglobinopathies.
Hypoxia-Inducible Factor 1 (HIF-1) is a transcription factor that plays a crucial role in the body's response to low oxygen levels, also known as hypoxia. HIF-1 is a heterodimeric protein composed of two subunits: an alpha subunit (HIF-1α) and a beta subunit (HIF-1β).
The alpha subunit, HIF-1α, is the regulatory subunit that is subject to oxygen-dependent degradation. Under normal oxygen conditions (normoxia), HIF-1α is constantly produced in the cell but is rapidly degraded by proteasomes due to hydroxylation of specific proline residues by prolyl hydroxylase domain-containing proteins (PHDs). This hydroxylation reaction requires oxygen as a substrate, and under hypoxic conditions, the activity of PHDs is inhibited, leading to the stabilization and accumulation of HIF-1α.
Once stabilized, HIF-1α translocates to the nucleus, where it heterodimerizes with HIF-1β and binds to hypoxia-responsive elements (HREs) in the promoter regions of target genes. This binding results in the activation of gene transcription programs that promote cellular adaptation to low oxygen levels. These adaptive responses include increased erythropoiesis, angiogenesis, glucose metabolism, and pH regulation, among others.
Therefore, HIF-1α is a critical regulator of the body's response to hypoxia, and its dysregulation has been implicated in various pathological conditions, including cancer, cardiovascular disease, and neurodegenerative disorders.
Hemoglobin A is the most common form of hemoglobin, which is the oxygen-carrying protein in red blood cells. Hemoglobin A is a tetramer composed of two alpha and two beta globin chains, each containing a heme group that binds to oxygen. It is typically measured in laboratory tests to assess for various medical conditions such as anemia or diabetes. In the context of diabetes, the measurement of hemoglobin A1c (a form of hemoglobin A that is glycated or bound to glucose) is used to monitor long-term blood sugar control.
Erythrocyte indices are a set of calculated values that provide information about the size and hemoglobin content of red blood cells (erythrocytes). These indices are commonly used in the complete blood count (CBC) test to help diagnose various types of anemia and other conditions affecting the red blood cells.
The three main erythrocyte indices are:
1. Mean Corpuscular Volume (MCV): This is the average volume of a single red blood cell, measured in femtoliters (fL). MCV helps to differentiate between microcytic, normocytic, and macrocytic anemia. Microcytic anemia is characterized by low MCV values (100 fL).
2. Mean Corpuscular Hemoglobin (MCH): This is the average amount of hemoglobin present in a single red blood cell, measured in picograms (pg). MCH helps to assess the oxygen-carrying capacity of red blood cells. Low MCH values may indicate hypochromic anemia, where the red blood cells have reduced hemoglobin content.
3. Mean Corpuscular Hemoglobin Concentration (MCHC): This is the average concentration of hemoglobin in a single red blood cell, measured as a percentage. MCHC reflects the hemoglobin concentration relative to the size of the red blood cells. Low MCHC values may indicate hypochromic anemia, while high MCHC values could suggest spherocytosis or other conditions affecting red blood cell shape and integrity.
These erythrocyte indices are calculated based on the red blood cell count, hemoglobin concentration, and hematocrit results obtained from a CBC test. They provide valuable information for healthcare professionals to diagnose and manage various hematological conditions.
Hemosiderosis is a medical condition characterized by the abnormal accumulation of hemosiderin, an iron-containing protein, in various organs and tissues of the body. Hemosiderin is derived from the breakdown of hemoglobin, which is the oxygen-carrying protein in red blood cells. When there is excessive breakdown of red blood cells or impaired clearance of hemosiderin, it can lead to its accumulation in organs such as the liver, spleen, and lungs.
Hemosiderosis can be classified into two types: primary and secondary. Primary hemosiderosis is a rare condition that is caused by genetic disorders affecting red blood cells, while secondary hemosiderosis is more common and is associated with various conditions that cause excessive breakdown of red blood cells or chronic inflammation. These conditions include hemolytic anemias, repeated blood transfusions, liver diseases, infections, and certain autoimmune disorders.
The accumulation of hemosiderin can lead to tissue damage and organ dysfunction, particularly in the lungs, where it can cause pulmonary fibrosis, and in the heart, where it can lead to heart failure. Hemosiderosis is typically diagnosed through a combination of medical history, physical examination, and laboratory tests, including blood tests and imaging studies such as chest X-rays or MRI scans. Treatment of hemosiderosis depends on the underlying cause and may include medications, blood transfusions, or supportive care to manage symptoms and prevent complications.
A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.
Delta-thalassemia is a type of thalassemia, which is an inherited blood disorder that affects the production of hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen throughout the body. In delta-thalassemia, there is a mutation or deletion in the gene that produces the delta-globin chain, which is one of the four chains that make up the adult hemoglobin molecule (HbA).
There are two types of delta-thalassemia:
1. Delta-thalassemia minor: This type of delta-thalassemia occurs when a person inherits one mutated or deleted delta-globin gene from one parent and one normal gene from the other parent. People with delta-thalassemia minor usually have mild anemia, which may not cause any symptoms.
2. Delta-thalassemia major: This type of delta-thalassemia occurs when a person inherits two mutated or deleted delta-globin genes, one from each parent. People with delta-thalassemia major have severe anemia and other complications, such as bone deformities, enlarged spleen, and growth retardation. They may require regular blood transfusions to manage their anemia.
Delta-thalassemia can also occur in combination with other types of thalassemia, such as beta-thalassemia, which can further complicate the clinical picture. Treatment for delta-thalassemia depends on the severity of the condition and may include blood transfusions, iron chelation therapy, and occasionally bone marrow transplantation.
Erythropoiesis is the process of forming and developing red blood cells (erythrocytes) in the body. It occurs in the bone marrow and is regulated by the hormone erythropoietin (EPO), which is produced by the kidneys. Erythropoiesis involves the differentiation and maturation of immature red blood cell precursors called erythroblasts into mature red blood cells, which are responsible for carrying oxygen to the body's tissues. Disorders that affect erythropoiesis can lead to anemia or other blood-related conditions.
Hemoglobinometry is a method used to measure the amount or concentration of hemoglobin (Hb) in blood. Hemoglobin is a protein in red blood cells that carries oxygen throughout the body. Hemoglobinometry is typically performed on a sample of whole blood and can be done using various methods, including spectrophotometry, colorimetry, or automated analyzers.
The results of hemoglobinometry are reported in units of grams per deciliter (g/dL) or grams per liter (g/L). Normal values for hemoglobin concentration vary depending on factors such as age, sex, and altitude, but in general, a healthy adult male should have a hemoglobin level between 13.5 and 17.5 g/dL, while a healthy adult female should have a level between 12.0 and 15.5 g/dL.
Hemoglobinometry is an important diagnostic tool in the evaluation of various medical conditions, including anemia, polycythemia, and respiratory disorders. It can help identify the cause of symptoms such as fatigue, shortness of breath, or dizziness and guide treatment decisions.
The alpha7 nicotinic acetylcholine receptor (α7nAChR) is a type of cholinergic receptor found in the nervous system that is activated by the neurotransmitter acetylcholine. It is a ligand-gated ion channel that is widely distributed throughout the central and peripheral nervous systems, including in the hippocampus, cortex, thalamus, and autonomic ganglia.
The α7nAChR is composed of five subunits arranged around a central pore, and it has a high permeability to calcium ions (Ca2+). When acetylcholine binds to the receptor, it triggers a conformational change that opens the ion channel, allowing Ca2+ to flow into the cell. This influx of Ca2+ can activate various intracellular signaling pathways and have excitatory or inhibitory effects on neuronal activity, depending on the location and function of the receptor.
The α7nAChR has been implicated in a variety of physiological processes, including learning and memory, attention, sensory perception, and motor control. It has also been studied as a potential therapeutic target for various neurological and psychiatric disorders, such as Alzheimer's disease, schizophrenia, and pain.
A splenectomy is a surgical procedure in which the spleen is removed from the body. The spleen is an organ located in the upper left quadrant of the abdomen, near the stomach and behind the ribs. It plays several important roles in the body, including fighting certain types of infections, removing old or damaged red blood cells from the circulation, and storing platelets and white blood cells.
There are several reasons why a splenectomy may be necessary, including:
* Trauma to the spleen that cannot be repaired
* Certain types of cancer, such as Hodgkin's lymphoma or non-Hodgkin's lymphoma
* Sickle cell disease, which can cause the spleen to enlarge and become damaged
* A ruptured spleen, which can be life-threatening if not treated promptly
* Certain blood disorders, such as idiopathic thrombocytopenic purpura (ITP) or hemolytic anemia
A splenectomy is typically performed under general anesthesia and may be done using open surgery or laparoscopically. After the spleen is removed, the incision(s) are closed with sutures or staples. Recovery time varies depending on the individual and the type of surgery performed, but most people are able to return to their normal activities within a few weeks.
It's important to note that following a splenectomy, individuals may be at increased risk for certain types of infections, so it's recommended that they receive vaccinations to help protect against these infections. They should also seek medical attention promptly if they develop fever, chills, or other signs of infection.
Hemoglobin S (HbS) is a genetic variant of hemoglobin, which is the oxygen-carrying protein in red blood cells. This abnormal form of hemogllobin results from a mutation in the beta-globin gene, leading to the substitution of valine for glutamic acid at position six of the beta-globin chain.
In individuals with sickle cell disease (a group of inherited red blood cell disorders), both copies of their beta-globin genes carry this mutation, causing the majority of their hemoglobin to be HbS. When deoxygenated, HbS molecules have a tendency to polymerize and form long, rigid rods within the red blood cells, distorting their shape into a characteristic sickle or crescent form.
These sickled red blood cells are less flexible and more prone to rupture (hemolysis), leading to chronic anemia, vaso-occlusive crises, and other disease complications. Sickle cell disease primarily affects people of African, Mediterranean, Middle Eastern, and Indian ancestry, but it can also be found in other populations worldwide.
Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.
Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.
In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.
Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.
A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.
Integrin α3β1 is a type of cell surface receptor that is widely expressed in various tissues, including epithelial and endothelial cells. It is composed of two subunits, α3 and β1, which form a heterodimeric complex that plays a crucial role in cell-matrix adhesion and signaling.
Integrin α3β1 binds to several extracellular matrix proteins, such as laminin, fibronectin, and collagen IV, and mediates various cellular functions, including cell migration, proliferation, differentiation, and survival. It also participates in intracellular signaling pathways that regulate cell behavior and tissue homeostasis.
Mutations in the genes encoding integrin α3β1 have been associated with several human diseases, including blistering skin disorders, kidney disease, and cancer. Therefore, understanding the structure, function, and regulation of integrin α3β1 is essential for developing new therapeutic strategies to treat these conditions.