|
Toxoid Vaccines
A toxoid is an inactivated toxin (usually an exotoxin) whose toxicity has been suppressed either by chemical (formalin) or heat treatment, while other properties, typically immunogenicity, are maintained. Toxins are secreted by bacteria, whereas toxoids are altered form of toxins; toxoids are ''not'' secreted by bacteria. Thus, when used during vaccination, an immune response is mounted and immunological memory is formed against the molecular markers of the toxoid without resulting in toxin-induced illness. Such a preparation is also known as an anatoxin. There are toxoids for prevention of diphtheria, tetanus and botulism. Toxoids are used as vaccines because they induce an immune response to the original toxin or increase the response to another antigen since the toxoid markers and toxin markers are preserved. For example, the tetanus toxoid is derived from the tetanospasmin produced by ''Clostridium tetani''. The latter causes tetanus and is vaccinated against by the DTaP vac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruby Hirose
Ruby Sakae Hirose (1904–1960) was an American biochemist and bacteriologist. She did research on blood clotting and thrombin, allergies, and researched cancer using antimetabolites. Family and early life Ruby Hirose was born to Shiusaka (father) Hirose and Tome (née Kurai) in Kent, Washington, on August 30, 1904. She was the second child of seven children in the family, but because the first child died very young, grew up as the oldest child of six in the family. She had four sisters and one brother, and they lived in the White River (Shirakawa) area around Seattle. The second child in the family was Fumiko, two years younger than Ruby. Fumi, as she was called, contracted tuberculosis as did her mother. Fumi died in 1925 and her mother Tome died in 1934. The third child in the family was brother Kimeo, who was two years younger than Fumi and excelled in sports in high school, lettering in three sports, and was named football captain and class treasurer. He lived until 1991. Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antitoxin
An antitoxin is an antibody with the ability to neutralize a specific toxin. Antitoxins are produced by certain animals, plants, and bacterium, bacteria in response to toxin exposure. Although they are most effective in neutralizing toxins, they can also kill bacteria and other microorganisms. Antitoxins are made within organisms, and can be injected into other organisms, including humans, to treat an infectious disease. This procedure involves injecting an animal with a safe amount of a particular toxin. The animal's body then makes the antitoxin needed to neutralize the toxin. Later, blood is withdrawn from the animal. When the antitoxin is obtained from the blood, it is purified and injected into a human or other animal, inducing temporary passive immunity. To prevent serum sickness, it is often best to use an antitoxin obtained from the same species (e.g. use human antitoxin to treat humans). Most antitoxin preparations are prepared from donors with high titers of antibody ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pertussis Toxin
Pertussis toxin (PT) is a protein-based AB5-type exotoxin produced by the bacterium ''Bordetella pertussis'', which causes whooping cough. PT is involved in the colonization of the respiratory tract and the establishment of infection. Research suggests PT may have a therapeutic role in treating a number of common human ailments, including hypertension, viral infection, and autoimmunity. History PT clearly plays a central role in the pathogenesis of pertussis although this was discovered only in the early 1980s. The appearance of pertussis is quite recent, compared with other epidemic infectious diseases. The earliest mention of pertussis, or whooping cough, is of an outbreak in Paris in 1414. This was published in Moulton's The Mirror of Health, in 1640. Another epidemic of pertussis took place in Paris in 1578 and was described by a contemporary observer, Guillaume de Baillou. Pertussis was well known throughout Europe by the middle of the 18th century. Jules Bordet and O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clostridium Botulinum
''Clostridium botulinum'' is a Gram-positive, rod-shaped, anaerobic, spore-forming, motile bacterium with the ability to produce the neurotoxin botulinum. The botulinum toxin can cause botulism, a severe flaccid paralytic disease in humans and other animals, and is the most potent toxin known to mankind, natural or synthetic, with a lethal dose of 1.3–2.1 ng/kg in humans.(2010). Chapter 19. ''Clostridium'', ''Peptostreptococcus'', ''Bacteroides'', and Other Anaerobes. In Ryan K.J., Ray C (Eds), ''Sherris Medical Microbiology'', 5th ed. ''C. botulinum'' is a diverse group of pathogenic bacteria initially grouped together by their ability to produce botulinum toxin and now known as four distinct groups, ''C. botulinum'' groups I–IV, as well as some strains of ''Clostridium butyricum'' and ''Clostridium baratii'', are the bacteria responsible for producing botulinum toxin. ''C. botulinum'' is responsible for foodborne botulism (ingestion of preformed toxin), infant bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Botulinum Toxin
Botulinum toxin, or botulinum neurotoxin (BoNT), is a neurotoxic protein produced by the bacterium ''Clostridium botulinum'' and related species. It prevents the release of the neurotransmitter acetylcholine from axon endings at the neuromuscular junction, thus causing flaccid paralysis. The toxin causes the disease botulism. The toxin is also used commercially for medical and cosmetic purposes. The seven main types of botulinum toxin are named types A to G (A, B, C1, C2, D, E, F and G). New types are occasionally found. Types A and B are capable of causing disease in humans, and are also used commercially and medically. Types C–G are less common; types E and F can cause disease in humans, while the other types cause disease in other animals. Botulinum toxins are among the most potent toxins known. Intoxication can occur naturally as a result of either wound or intestinal infection or by ingesting formed toxin in food. The estimated human lethal dose of type A toxin is 1.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphtheria Toxoid
Diphtheria vaccine is a toxoid vaccine against diphtheria, an illness caused by ''Corynebacterium diphtheriae''. Its use has resulted in a more than 90% decrease in number of cases globally between 1980 and 2000. The first dose is recommended at six weeks of age with two additional doses four weeks apart, after which it is about 95% effective during childhood. Three further doses are recommended during childhood. It is unclear if further doses later in life are needed. The diphtheria vaccine is very safe. Significant side effects are rare. Pain may occur at the injection site. A bump may form at the site of injection that lasts a few weeks. The vaccine is safe in both pregnancy and among those who have a poor immune function. The diphtheria vaccine is delivered in several combinations. Some combinations (Td and DT vaccines) include tetanus vaccine, others (known as DPT vaccine or DTaP vaccine depending on the pertussis antigen used) comes with the tetanus and pertussis vaccin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diphtheria Toxin
Diphtheria toxin is an exotoxin secreted by '' Corynebacterium diphtheriae'', the pathogenic bacterium that causes diphtheria. The toxin gene is encoded by a prophageA prophage is a virus that has inserted itself into the genome of the host bacterium. called corynephage β. The toxin causes the disease in humans by gaining entry into the cell cytoplasm and inhibiting protein synthesis. Structure Diphtheria toxin is a single polypeptide chain of 535 amino acids consisting of two subunits linked by disulfide bridges, known as an A-B toxin. Binding to the cell surface of the B subunit (the less stable of the two subunits) allows the A subunit (the more stable part of the protein) to penetrate the host cell. The crystal structure of the diphtheria toxin homodimer has been determined to 2.5 Ångstrom resolution. The structure reveals a Y-shaped molecule consisting of three domains. Fragment A contains the catalytic C domain, and fragment B consists of the T and R domains: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetanus Toxoid
Tetanus vaccine, also known as tetanus toxoid (TT), is a toxoid vaccine used to prevent tetanus. During childhood, five doses are recommended, with a sixth given during adolescence. After three doses, almost everyone is initially immune, but additional doses every ten years are recommended to maintain immunity. A booster shot should be given within 48 hours of an injury to people whose immunization is out of date. For people with high-risk injuries who are not fully immunized, tetanus antitoxin may also be recommended. Confirming that pregnant women are up to date on tetanus immunization during each pregnancy can prevent both maternal and neonatal tetanus. The vaccine is very safe, including during pregnancy and in those with HIV/AIDS. Redness and pain at the site of injection occur in between 25% and 85% of people. Fever, feeling tired, and minor muscle pain occurs in less than 10% of people. Severe allergic reactions occur in less than one in 100,000 people. A number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetanus Toxin
Tetanus toxin (TeNT) is an extremely potent neurotoxin produced by the vegetative cell of ''Clostridium tetani'' in anaerobic conditions, causing tetanus. It has no known function for clostridia in the soil environment where they are normally encountered. It is also called spasmogenic toxin, tentoxilysin, tetanospasmin or, tetanus neurotoxin. The LD50 of this toxin has been measured to be approximately 2.5–3 ng/kg, making it second only to the related botulinum toxin (LD50 2 ng/kg) as the deadliest toxin in the world. However, these tests are conducted solely on mice, which may react to the toxin differently from humans and other animals. ''C. tetani'' also produces the exotoxin tetanolysin, a hemolysin, that causes destruction of tissues. Distribution Tetanus toxin spreads through tissue spaces into the lymphatic and vascular systems. It enters the nervous system at the neuromuscular junctions and migrates through nerve trunks and into the central nervous sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacterial Capsule
The bacteria capsule is a large structure common to many bacteria. It is a polysaccharide layer that lies outside the cell envelope, and is thus deemed part of the outer envelope of a bacterial cell. It is a well-organized layer, not easily washed off, and it can be the cause of various diseases. The capsule—which can be found in both gram negative and gram-positive bacteria—is different from the second lipid membrane – bacterial outer membrane, which contains lipopolysaccharides and lipoproteins and is found only in gram-negative bacteria. When the amorphous viscid secretion (that makes up the capsule) diffuses into the surrounding medium and remains as a loose undemarcated secretion, it is known as a slime layer. Capsule and slime layer are sometimes summarized under the term glycocalyx. Composition Most bacterial capsules are composed of polysaccharide, but some species use other materials, such as poly- D-glutamic acid in ''Bacillus anthracis''. Because most capsul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conjugate Vaccine
A conjugate vaccine is a type of subunit vaccine which combines a weak antigen with a strong antigen as a carrier so that the immune system has a stronger response to the weak antigen. Vaccines are used to prevent diseases by invoking an immune response to an antigen, part of a bacterium or virus that the immune system recognizes. This is usually accomplished with an attenuated or dead version of a pathogenic bacterium or virus in the vaccine, so that the immune system can recognize the antigen later in life. Most vaccines contain a single antigen that the body will recognize. However, the antigen of some pathogens does not elicit a strong response from the immune system, so a vaccination against this weak antigen would not protect the person later in life. In this case, a conjugate vaccine is used in order to invoke an immune system response against the weak antigen. In a conjugate vaccine, the weak antigen is covalently attached to a strong antigen, thereby eliciting a stronge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passive Immunity
Passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially, when high levels of antibodies specific to a pathogen or toxin (obtained from humans, horses, or other animals) are transferred to non-immune persons through blood products that contain antibodies, such as in immunoglobulin therapy or antiserum therapy. Passive immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response, or to reduce the symptoms of ongoing or immunosuppressive diseases.Microbiology and Immunology On-Line Textbook : USC School of Medicine Passive immunization can be provided when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Botulinum Toxin")
