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ADA-SCID
Adenosine deaminase deficiency (ADA deficiency) is a metabolic disorder that causes immunodeficiency. It is caused by mutations in the ADA gene. It accounts for about 10–15% of all cases of autosomal recessive forms of severe combined immunodeficiency (SCID) among non-inbred populations. ADA deficiency can present in infancy, childhood, adolescence, or adulthood. Age of onset and severity is related to some 29 known genotypes associated with the disorder. It occurs in fewer than one in 100,000 live births worldwide. Signs and symptoms The main symptoms of ADA deficiency are pneumonia, chronic diarrhea, and widespread skin rashes. Affected children also grow much more slowly than healthy children and some have developmental delay. Most individuals with ADA deficiency are diagnosed with SCID in the first 6 months of life. An association with polyarteritis nodosa has been reported.Liebowitz J, Hellmann DB1, Schnappauf O (2019) Thirty years of followup in 3 patients with fam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Severe Combined Immunodeficiency
Severe combined immunodeficiency (SCID), also known as Swiss-type agammaglobulinemia, is a rare genetic disorder characterized by the disturbed development of functional T cells and B cells caused by numerous genetic mutations that result in differing clinical presentations. SCID involves defective antibody response due to either direct involvement with B lymphocytes or through improper B lymphocyte activation due to non-functional T-helper cells. Consequently, both "arms" (B cells and T cells) of the adaptive immune system are impaired due to a defect in one of several possible genes. SCID is the most severe form of primary immunodeficiencies, and there are now at least nine different known genes in which mutations lead to a form of SCID. It is also known as the bubble boy disease and bubble baby disease because its victims are extremely vulnerable to infectious diseases and some of them, such as David Vetter, have become famous for living in a sterile environment. SCID is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ADA (gene)
Adenosine deaminase (also known as adenosine aminohydrolase, or ADA) is an enzyme () involved in purine metabolism. It is needed for the breakdown of adenosine from food and for the turnover of nucleic acids in tissues. Its primary function in humans is the development and maintenance of the immune system. However, the full physiological role of ADA is not yet completely understood. Structure ADA exists in both small form (as a monomer) and large form (as a dimer-complex). In the monomer form, the enzyme is a polypeptide chain, folded into eight strands of parallel α/β barrels, which surround a central deep pocket that is the active site. In addition to the eight central β-barrels and eight peripheral α-helices, ADA also contains five additional helices: residues 19-76 fold into three helices, located between β1 and α1 folds; and two antiparallel carboxy-terminal helices are located across the amino-terminal of the β-barrel. The ADA active site contains a zinc ion, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deoxyadenosine
Deoxyadenosine (symbol dA or dAdo) is a deoxyribonucleoside. It is a derivative of the nucleoside adenosine, differing from the latter by the replacement of a hydroxyl group (-OH) by hydrogen (-H) at the 2′ position of its ribose sugar moiety. Deoxyadenosine is the DNA nucleoside A, which pairs with deoxythymidine (T) in double-stranded DNA. In absence of adenosine deaminase (ADA) it accumulates in T lymphocytes and kills these cells resulting in a genetic disorder known as adenosine deaminase severe combined immunodeficiency disease (ADA-SCID). See also *Deoxyribonucleotide *Cordycepin (3′-deoxyadenosine) *Severe combined immunodeficiency Severe combined immunodeficiency (SCID), also known as Swiss-type agammaglobulinemia, is a rare genetic disorder characterized by the disturbed development of functional T cells and B cells caused by numerous genetic mutations that result in diffe ... References Nucleosides Purines Hydroxymethyl compounds {{Cell-biology-st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenosine Deaminase
Adenosine deaminase (also known as adenosine aminohydrolase, or ADA) is an enzyme () involved in purine metabolism. It is needed for the breakdown of adenosine from food and for the turnover of nucleic acids in tissues. Its primary function in humans is the development and maintenance of the immune system. However, the full physiological role of ADA is not yet completely understood. Structure ADA exists in both small form (as a monomer) and large form (as a dimer-complex). In the monomer form, the enzyme is a polypeptide chain, folded into eight strands of parallel α/β barrels, which surround a central deep pocket that is the active site. In addition to the eight central β-barrels and eight peripheral α-helices, ADA also contains five additional helices: residues 19-76 fold into three helices, located between β1 and α1 folds; and two antiparallel carboxy-terminal helices are located across the amino-terminal of the β-barrel. The ADA active site contains a zinc ion, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolic Disorder
A metabolic disorder is a disorder that negatively alters the body's processing and distribution of macronutrients, such as proteins, fats, and carbohydrates. Metabolic disorders can happen when abnormal chemical reactions in the body alter the normal metabolic process. It can also be defined as inherited single gene anomaly, most of which are autosomal recessive. Signs and symptoms Some of the symptoms that can occur with metabolic disorders are lethargy, weight loss, jaundice and seizures. The symptoms expressed would vary with the type of metabolic disorder. There are four categories of symptoms: acute symptoms, late-onset acute symptoms, progressive general symptoms and permanent symptoms. Causes Inherited metabolic disorders are one cause of metabolic disorders, and occur when a defective gene causes an enzyme deficiency. These diseases, of which there are many subtypes, are known as inborn errors of metabolism. Metabolic diseases can also occur when the liver or pancre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against virus infections. Other basic immune mechanisms evolved in ancient plants and animals and remain in their modern descendants. These mechanisms include phagocytosis, antimicrobial pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Purine Salvage Pathway
A salvage pathway is a pathway in which a biological product is produced from intermediates in the degradative pathway of its own or a similar substance. The term often refers to nucleotide salvage in particular, in which nucleotides (purine and pyrimidine) are synthesized from intermediates in their degradative pathway. Nucleotide salvage pathways are used to recover bases and nucleosides that are formed during degradation of RNA and DNA. This is important in some organs because some tissues cannot undergo de novo synthesis. The salvaged products can then be converted back into nucleotides. Salvage pathways are targets for drug development, one family being called antifolates. A number of other biologically-important substances, like methionine and nicotinate, have their own salvage pathways to recycle parts of the molecule. Substrates The nucleotide salvage pathway requires distinct substrates: Pyrimidines Uridine phosphorylase or pyrimidine-nucleoside phosphorylase substit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphocytes
A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity). They are the main type of cell found in lymph, which prompted the name "lymphocyte". Lymphocytes make up between 18% and 42% of circulating white blood cells. Types The three major types of lymphocyte are T cells, B cells and natural killer (NK) cells. Lymphocytes can be identified by their large nucleus. T cells and B cells T cells (thymus cells) and B cells ( bone marrow- or bursa-derived cells) are the major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity (relating to antibodies). The function of T cells and B cells is to recognize specif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymus
The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus is located in the upper front part of the chest, in the anterior superior mediastinum, behind the sternum, and in front of the heart. It is made up of two lobes, each consisting of a central medulla and an outer cortex, surrounded by a capsule. The thymus is made up of immature T cells called thymocytes, as well as lining cells called epithelial cells which help the thymocytes develop. T cells that successfully develop react appropriately with MHC immune receptors of the body (called ''positive selection'') and not against proteins of the body (called ''negative selection''). The thymus is largest and most active during the neonatal and pre-adolescent periods. By the early teens, the thymus begins to decrease in size and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyethylene Glycol
Polyethylene glycol (PEG; ) is a polyether compound derived from petroleum with many applications, from industrial manufacturing to medicine. PEG is also known as polyethylene oxide (PEO) or polyoxyethylene (POE), depending on its molecular weight. The structure of PEG is commonly expressed as H−(O−CH2−CH2)n−OH. Uses Medical uses * Pharmaceutical-grade PEG is used as an excipient in many pharmaceutical products, in oral, topical, and parenteral dosage forms. * PEG is the basis of a number of laxatives (as ''MiraLax''). Whole bowel irrigation with polyethylene glycol and added electrolytes is used for bowel preparation before surgery or colonoscopy. * PEG is used in medicines for treating disimpaction and maintenance therapy for children with constipation. * When attached to various protein medications or drug carriers, polyethylene glycol of suitable length slows down their clearance from the blood. * The possibility that PEG could be used to fuse axons is being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bone Marrow Transplant
Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood in order to replicate inside of a patient and to produce additional normal blood cells. It may be autologous (the patient's own stem cells are used), allogeneic (the stem cells come from a donor) or syngeneic (from an identical twin). It is most often performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma or leukemia. In these cases, the recipient's immune system is usually destroyed with radiation or chemotherapy before the transplantation. Infection and graft-versus-host disease are major complications of allogeneic HSCT. HSCT remains a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. As survival following the procedure has increased, its use has expanded beyond cancer to autoimmune ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B Cell
B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or inserted into the plasma membrane where they serve as a part of B-cell receptors. When a naïve or memory B cell is activated by an antigen, it proliferates and differentiates into an antibody-secreting effector cell, known as a plasmablast or plasma cell. Additionally, B cells present antigens (they are also classified as professional antigen-presenting cells (APCs)) and secrete cytokines. In mammals, B cells mature in the bone marrow, which is at the core of most bones. In birds, B cells mature in the bursa of Fabricius, a lymphoid organ where they were first discovered by Chang and Glick, which is why the 'B' stands for bursa and not bone marrow as commonly believed. B cells, unlike the other two classes of lymphocytes, T cells and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
