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Classical Complement Pathway
The classical complement pathway is one of three pathways which activate the complement system, which is part of the immune system. The classical complement pathway is initiated by antigen-antibody complexes with the antibody isotypes IgG and IgM. Following activation, a series of proteins are recruited to generate C3 convertase (C4b2b, historically referred C4b2a), which cleaves the C3 protein. The C3b component of the cleaved C3 binds to C3 convertase (C4b2b) to generate C5 convertase (C4b2b3b), which cleaves the C5 protein. The cleaved products attract phagocytes to the site of infection and tags target cells for elimination by phagocytosis. In addition, the C5 convertase initiates the terminal phase of the complement system, leading to the assembly of the membrane attack complex (MAC). The membrane attack complex creates a pore on the target cell's membrane, inducing cell lysis and death. The classical complement pathway can also be activated by apoptotic cells, nec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complement Pathways
Complement may refer to: The arts * Complement (music), an interval that, when added to another, spans an octave ** Aggregate complementation, the separation of pitch-class collections into complementary sets * Complementary color, in the visual arts Biology and medicine *Complement system (immunology), a cascade of proteins in the blood that form part of innate immunity *Complementary DNA, DNA reverse transcribed from a mature mRNA template *Complementarity (molecular biology), a property whereby double stranded nucleic acids pair with each other *Complementation (genetics), a test to determine if independent recessive mutant phenotypes are caused by mutations in the same gene or in different genes Grammar and linguistics * Complement (linguistics), a word or phrase having a particular syntactic role ** Subject complement, a word or phrase adding to a clause's subject after a linking verb **Object complement, a word or phrase adding to the direct object of a verb phrase. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternative Complement Pathway
The alternative pathway is a type of cascade reaction of the complement system and is a component of the innate immune system, a natural defense against infections. The alternative pathway is one of three complement pathways that opsonize and kill pathogens. The pathway is triggered when the C3b protein directly binds a microbe. It can also be triggered by foreign materials and damaged tissues. Signaling cascade This change in shape allows the binding of plasma protein Factor B, which allows Factor D to cleave Factor B into Ba and Bb. Bb remains bound to C3(H2O) to form C3(H2O)Bb. This complex is also known as a fluid-phase C3-convertase. This convertase, the alternative pathway C3-convertase, although only produced in small amounts, can cleave multiple C3 proteins into C3a and C3b. The complex is believed to be unstable until it binds properdin, a serum protein. The addition of properdin forms the complex C3bBbP, a stable compound which can bind an additional C3b to f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemic Lupus Erythematosus
Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common symptoms include painful and swollen joints, fever, chest pain, hair loss, mouth ulcers, swollen lymph nodes, feeling tired, and a red rash which is most commonly on the face. Often there are periods of illness, called flares, and periods of remission during which there are few symptoms. Children up to 18 years old develop a more severe form of SLE termed childhood-onset systemic lupus erythematosus. The cause of SLE is not clear. It is thought to involve a combination of genetics and environmental factors. Among identical twins, if one is affected there is a 24% chance the other one will also develop the disease. Female sex hormones, sunlight, smoking, vitamin D deficiency, and certain infections are also believed to increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food And Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food safety, tobacco products, caffeine products, dietary supplements, Prescription drug, prescription and Over-the-counter drug, over-the-counter pharmaceutical drugs (medications), vaccines, biopharmaceuticals, blood transfusions, medical devices, electromagnetic radiation emitting devices (ERED), cosmetics, Animal feed, animal foods & feed and Veterinary medicine, veterinary products. The FDA's primary focus is enforcement of the Federal Food, Drug, and Cosmetic Act (FD&C). However, the agency also enforces other laws, notably Section 361 of the Public Health Service Act as well as associated regulations. Much of this regulatory-enforcement work is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angioedema
Angioedema is an area of swelling (edema) of the lower layer of skin and tissue just under the skin or mucous membranes. The swelling may occur in the face, tongue, larynx, abdomen, or arms and legs. Often it is associated with hives, which are swelling within the upper skin. Onset is typically over minutes to hours. The underlying mechanism typically involves histamine or bradykinin. The version related to histamine is due to an allergic reaction to agents such as insect bites, foods, or medications. The version related to bradykinin may occur due to an inherited problem known as C1 esterase inhibitor deficiency, medications known as angiotensin-converting enzyme inhibitors, or a lymphoproliferative disorder. Treatment to protect the airway may include intubation or cricothyroidotomy. Histamine-related angioedema can be treated with antihistamines, corticosteroids, and epinephrine. In those with bradykinin-related disease a C1 esterase inhibitor, ecallantide, or icati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C1-inhibitor
C1-inhibitor (C1-inh, C1 esterase inhibitor) is a protease inhibitor belonging to the serpin superfamily. Its main function is the inhibition of the complement system (C1r, C1s) to prevent spontaneous activation but also as the major regulator of the contact system (PK, FXIIa, and FXIa). Proteomics C1-inhibitor is the largest member among the ''serpin'' superfamily of proteins. It can be noted that, unlike most family members, C1-inhibitor has a 2- domain structure. The C-terminal serpin domain is similar to other serpins, which is the part of C1-inhibitor that provides the inhibitory activity. The N-terminal domain (also some times referred to as the ''N-terminal tail'') is not essential for C1-inhibitor to inhibit proteases. This domain has no similarity to other proteins. C1-inhibitor is highly glycosylated, bearing both ''N''- and ''O''-glycans. N-terminal domain is especially heavily glycosylated. Role in disease Deficiency of this protein is associated with here ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tachyplesin
Tachyplesin I and Tachyplesin II Tachyplesin is an antimicrobial peptide isolated from the horseshoe crab Horseshoe crabs are arthropods of the family Limulidae and the only surviving xiphosurans. Despite their name, they are not true crabs or even crustaceans; they are chelicerates, more closely related to arachnids like spiders, ticks, and scor ... with a molecular weight of 2.36 kDa and the amino acid sequence KWCFRVCYRGICYRRCR. References Further reading * Antimicrobial peptides {{Antibiotic-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Staphylococcus Aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe, meaning that it can grow without oxygen. Although ''S. aureus'' usually acts as a commensal of the human microbiota, it can also become an opportunistic pathogen, being a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. ''S. aureus'' is one of the leading pathogens for deaths associated with antimicrobial resistance and the emergence of antibiotic-resistant strains, such as methicillin-resistant ''S. aur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insulin Resistance
Insulin resistance (IR) is a pathological response in which cells in insulin-sensitive tissues in the body fail to respond normally to the hormone insulin or downregulate insulin receptors in response to hyperinsulinemia. Insulin is a hormone that facilitates the transport of glucose from blood into cells, thereby reducing blood glucose (blood sugar). Insulin is released by the pancreas in response to carbohydrates consumed in the diet. In states of insulin resistance, the same amount of insulin does not have the same effect on glucose transport and blood sugar levels. There are many causes of insulin resistance and the underlying process is still not completely understood. Risk factors for insulin resistance include obesity, sedentary lifestyle, family history of diabetes, various health conditions, and certain medications. Insulin resistance is considered a component of the metabolic syndrome. Insulin resistance can be improved or reversed with lifestyle approaches, such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obesity
Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classified as obese when their body mass index (BMI)—a person's weight divided by the square of the person's height—is over ; the range is defined as overweight. Some East Asian countries use lower values to calculate obesity. Obesity is a major cause of disability and is Obesity-associated morbidity, correlated with various diseases and conditions, particularly cardiovascular diseases, type 2 diabetes, obstructive sleep apnea, certain types of cancer, and osteoarthritis. Obesity has individual, socioeconomic, and environmental causes. Some known causes are Western pattern diet, diet, low physical activity, automation, urbanization, quantitative trait locus, genetic susceptibility, medications, mental disorders, Economic policy, economic pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C3a Receptor
The C3a receptor also known as complement component 3a receptor 1 (C3AR1) is a G protein-coupled receptor protein involved in the complement system. The receptor binds to complement component C3a, although there is limited evidence that this receptor also binds C4a in lesser mammals. This has yet to be proven true in humans. C3a receptor modulates immunity, arthritis, diet-induced obesity and cancers. Agonists and antagonists Potent and selective agonists and antagonists An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaphylatoxin
Anaphylatoxins, or complement peptides, are fragments ( C3a, C4a and C5a) that are produced as part of the activation of the complement system. Complement components C3, C4 and C5 are large glycoproteins that have important functions in the immune response and host defense. They have a wide variety of biological activities and are proteolytically activated by cleavage at a specific site, forming a- and b-fragments. A-fragments form distinct structural domains of approximately 76 amino acids, coded for by a single exon within the complement protein gene. The C3a, C4a and C5a components are referred to as anaphylatoxins: they cause smooth muscle contraction, vasodilation, histamine release from mast cells, and enhanced vascular permeability. They also mediate chemotaxis, inflammation, and generation of cytotoxic oxygen radicals. The proteins are highly hydrophilic, with a mainly alpha-helical structure held together by 3 disulfide bridges. Function Anaphylatoxins are able to tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
