|
Fernandez Reaction
The Fernandez reaction is a reaction that occurs to signal a positive result in the lepromin skin test for leprosy. The reaction occurs in the skin at the site of injection if the body possesses antibodies to the Dharmendra antigen, one of the antigens found in Mycobacterium leprae, the bacteria that causes leprosy. The reaction occurs via a delayed-type hypersensitivity mechanism. This reaction occurs within 48 hours of injection of lepromin and is seen in only tuberculoid forms of leprosy. This represents a delayed-type hypersensitivity reaction. In contrast, the Mitsuda reaction (delayed granulomatous lesion) occurs 3–4 weeks after injection of lepromin and is only seen in patients with the tuberculoid form of leprosy (not the lepromatous form, in which the body does not mount a strong response against the bacterium). In terms of mechanism of action and appearance, the reaction is similar to the tuberculin reaction of a positive Mantoux test for tuberculosis Tuberc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepromin
The lepromin skin test is used to determine what type of leprosy a person is infected with. It involves the injection of a standardized extract of the inactivated "''leprosy bacillus''" (''Mycobacterium leprae'' or "Hansen's bacillus") under the skin. It is not recommended as a primary mode of diagnosis. Method Positive reaction means: A) or more induration after 48hrs B) or above nodule after 21 days. An extract sample of inactivated Hansen's bacillus is injected just under the skin, usually on the forearm, so that a small lump pushes the skin upward. The lump indicates that the antigen has been injected at the correct depth. The injection site is labeled and examined at 48hours and 21 days later to see if there is a reaction. People with dermatitis or other skin irritations should have the test performed on an unaffected part of the body. If a child needs to have this test performed, it may be helpful to explain how the test will feel, and even practice or demonstrate on a dol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leprosy
Leprosy, also known as Hansen's disease (HD), is a long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the nerves, respiratory tract, skin, and eyes. This nerve damage may result in a lack of ability to feel pain, which can lead to the loss of parts of a person's extremities from repeated injuries or infection through unnoticed wounds. An infected person may also experience muscle weakness and poor eyesight. Leprosy symptoms may begin within one year, but, for some people, symptoms may take 20 years or more to occur. Leprosy is spread between people, although extensive contact is necessary. Leprosy has a low pathogenicity, and 95% of people who contract ''M. leprae'' do not develop the disease. Spread is thought to occur through a cough or contact with fluid from the nose of a person infected by leprosy. Genetic factors and immune function play a role in how easily a person catches the disease. Lepro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibody
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs in a few varia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dharmendra Antigen
The Dharmendra antigen is a test widely used in India. The antigen is a suspension of de-fatted leprosy bacilli which has been extracted with chloroform-ether and killed, either by heat, or by other effective methods. This antigen was first reported by Dharmendra in 1941–42 and later standardized in 1979 by Sangupta et al.Mohanty J, Mohanty H C. Lepromin response with dharmendra antigen in patients with leprosy. Indian J Dermatol Venereol Leprol erial online1997 ited 2016 Jun 2063:385-7. Available from: http://www.ijdvl.com/text.asp?1997/63/6/385/4627 Dharmendra's Lepromin suspension consists of 10 mg of the dried and de-fatted, bacillary powder, dissolved in 100 ml carbol saline solution. It is a revised form of the original Lepromin test developed in 1919 by Kensuke Mitsuda was a Japanese leprologist and director of the Tama Zenshoen Sanatorium (1914–1931) and the National Sanatorium Nagashima Aiseien (1931–1957). He had been at the frontier of leprosy policy of Ja ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antigen
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. The term ''antigen'' originally referred to a substance that is an antibody generator. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of monosaccharides/simple sugars), lipids, or nucleic acids. Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react and bind more than one antigen. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Leprae
''Mycobacterium leprae'' (also known as the leprosy bacillus or Hansen's bacillus), is one of the two species of bacteria that cause Hansen’s disease (leprosy), a chronic but curable infectious disease that damages the peripheral nerves and targets the skin, eyes, nose, and muscles. It is an acid-fast, Gram-positive, rod shaped bacterium and an obligate intracellular parasite, which means, unlike its relative ''Mycobacterium tuberculosis'', it cannot be grown in cell-free laboratory media. This is likely due to gene deletion and decay that the genome of the species has experienced via reductive evolution, which has caused the bacterium to depend heavily on its host for nutrients and metabolic intermediates. It has a narrow host range and apart from humans, the only other natural hosts are nine-banded armadillo and red squirrels. The bacteria infect mainly macrophages and Schwann cells, and are typically found congregated as a palisade. ''Mycobacterium leprae'' was sensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypersensitivity
Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune system and these reactions may be damaging and uncomfortable. This is an immunologic term and is not to be confused with the psychiatric term of being hypersensitive which implies to an individual who may be overly sensitive to physical (i.e. sound, touch, light, etc.) and/or emotional stimuli. Although there is a relation between the two – studies have shown that those individuals that have ADHD (a psychiatric disorder) are more likely to have hypersensitivity reactions such as allergies, asthma, eczema than those who do not have ADHD. Hypersensitivity reactions can be classified into four types. Type I: IgE mediated immediate reaction Type II: Antibody-mediated reaction (IgG or IgM antibodies) Type III: Immune complex-mediated rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculin
Tuberculin, also known as purified protein derivative, is a combination of proteins that are used in the diagnosis of tuberculosis. This use is referred to as the tuberculin skin test and is recommended only for those at high risk. Reliable administration of the skin test requires large amounts of training, supervision, and practice. Injection is done into the skin. After 48 to 72 hours, if there is more than a five to ten millimeter area of swelling, the test is considered positive. Common side effects include redness, itchiness, and pain at the site of injection. Allergic reactions may occasionally occur. The test may be falsely positive in those who have been previously vaccinated with BCG or have been infected by other types of mycobacteria. The test may be falsely negative within ten weeks of infection, in those less than six months old, and in those who have been infected for many years. Use is safe in pregnancy. Tuberculin was discovered in 1890 by Robert Koch. Koch, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mantoux Test
The Mantoux test or Mendel–Mantoux test (also known as the Mantoux screening test, tuberculin sensitivity test, Pirquet test, or PPD test for purified protein derivative) is a tool for screening for tuberculosis (TB) and for tuberculosis diagnosis. It is one of the major tuberculin skin tests used around the world, largely replacing multiple-puncture tests such as the tine test. The Heaf test, a form of tine test, was used until 2005 in the UK, when it was replaced by the Mantoux test. The Mantoux test is endorsed by the American Thoracic Society and Centers for Disease Control and Prevention. It was also used in the USSR and is now prevalent in most of the post-Soviet states. History Tuberculin is a glycerol extract of the tubercle bacillus. Purified protein derivative (PPD) tuberculin is a precipitate of species-nonspecific molecules obtained from filtrates of sterilized, concentrated cultures. The tuberculin reaction was first described by Robert Koch in 1890. The test ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in which case it is known as latent tuberculosis. Around 10% of latent infections progress to active disease which, if left untreated, kill about half of those affected. Typical symptoms of active TB are chronic cough with blood-containing mucus, fever, night sweats, and weight loss. It was historically referred to as consumption due to the weight loss associated with the disease. Infection of other organs can cause a wide range of symptoms. Tuberculosis is spread from one person to the next through the air when people who have active TB in their lungs cough, spit, speak, or sneeze. People with Latent TB do not spread the disease. Active infection occurs more often in people with HIV/AIDS and in those who smoke. Diagnosis of active TB is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skin Tests
Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different developmental origin, structure and chemical composition. The adjective cutaneous means "of the skin" (from Latin ''cutis'' 'skin'). In mammals, the skin is an organ of the integumentary system made up of multiple layers of ectodermal tissue and guards the underlying muscles, bones, ligaments, and internal organs. Skin of a different nature exists in amphibians, reptiles, and birds. Skin (including cutaneous and subcutaneous tissues) plays crucial roles in formation, structure, and function of extraskeletal apparatus such as horns of bovids (e.g., cattle) and rhinos, cervids' antlers, giraffids' ossicones, armadillos' osteoderm, and os penis/os clitoris. All mammals have some hair on their skin, even marine mammals like whales, dolp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
