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Immune system
hideAn immune system is a collection of biological processes within an organism that protects against disease by identifying and killing pathogens and tumour cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own healthy cells and tissues in order to function properly. Detection is complicated as pathogens can evolve rapidly, producing adaptations that avoid the immune system and allow the pathogens to successfully infect their hosts.
To survive this challenge, multiple mechanisms evolved that recognize and neutralize pathogens. Even simple unicellular organisms such as bacteria possess enzyme systems that protect against viral infections. Other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants, such as plants, fish, reptiles, and insects. These mechanisms include antimicrobial peptides called defensins, phagocytosis, and the complement system. Vertebrates such as humans have even more sophisticated defense mechanisms. The immune systems of vertebrates consist of many types of proteins, cells, organs, and tissues, which interact in an elaborate and dynamic network. As part of this more complex immune response, the human immune system adapts over time to recognise specific pathogens more efficiently. This adaptation process is referred to as "adaptive immunity" or "acquired immunity" and creates immunological memory. Immunological memory created from a primary response to a specific pathogen, provides an enhanced response to secondary encounters with that same, specific pathogen. This process of acquired immunity is the basis of vaccination.
Disorders in the immune system can result in disease. Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. Immunodeficiency can either be the result of a genetic disease, such as severe combined immunodeficiency, or be produced by pharmaceuticals or an infection, such as the acquired immune deficiency syndrome (AIDS) that is caused by the retrovirus HIV. In contrast, autoimmune diseases result from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto's Thyroiditis, rheumatoid arthritis, diabetes mellitus type 1 and lupus erythematosus. Immunology covers the study of all aspects of the immune system which has significant relevance to human health and diseases. Further investigation in this field is expected to play a serious role in promotion of health and treatment of diseases.
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News tagged with immune system
Researcher finds success with new anti-cancer drug
Dec 22, 2009 |
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A study conducted at Scott & White Healthcare in Temple, Texas, found that a new drug stopped the growth of breast tumors in mice. This drug is unique in that it works both by stopping the cancer cells from growing and metastasizing ...
Enzyme necessary for development of healthy immune system
Dec 22, 2009 |
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Mice without the deoxycytidine kinase (dCK) enzyme have defects in their adaptive immune system, producing very low levels of both T and B lymphocytes, the major players involved in immune response, according to a study by ...
Study redefines placebo effect as part of effective treatment
Medicine & Health / Psychology & Psychiatry
Dec 22, 2009 |
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Researchers used the placebo effect to successfully treat psoriasis patients with one quarter to one half of their usual dose of a widely used steroid medication, according to an early study published online today in the ...
CDC: Rare infection passed on by Miss. organ donor
Dec 19, 2009 |
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(AP) -- An extremely rare infection has been passed from an organ donor to at least one recipient in what is thought to be the first human-to-human transfer of the amoeba, medical officials said Friday.
Mutation leads to new and severe form of bacterial disease
Dec 18, 2009 |
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(PhysOrg.com) -- Everybody gets sick, but how sick you get is in your genes. New research now reveals a mutation on a gene that makes children susceptible to a severe form of mycobacterial disease. The work not only supports ...
IBM Reveals Five Innovations that Will Change Cities in the Next Five Years (w/ Video)
Dec 17, 2009 |
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Today, IBM unveiled a list of innovations that have the potential to change how people live, work and play in cities around the globe over the next five to ten years.
Breakthrough on causes of inflammatory bowel disease
Dec 17, 2009 |
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New research by the University of Adelaide could help explain why some people are more prone to Crohn's disease, ulcerative colitis and other autoimmune diseases.
Major breakthrough may pave the way for therapeutic vaccines
Dec 17, 2009 |
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It should be possible to use therapeutic vaccines to create both cheap and effective drugs for diseases like cancer and allergies. One problem in developing such vaccines has previously been the lack of adjuvants, substances ...
Patients meet donors from largest-ever kidney swap
Dec 16, 2009 |
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(AP) -- Thirteen patients with healthy new kidneys from what's believed to be the world's largest kidney exchange met the donors who made it happen Tuesday - including three who are sure to face the question, ...
Foodborne Staph Toxin Pinpointed by New Assay
Dec 15, 2009 |
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(PhysOrg.com) -- Most people need about two days to recover from being sickened by foods contaminated with what's known as staphylococcal enterotoxin A, or "SEA." Produced by Staphylococcus aureus bacteria, ...
Immune cell activity linked to worsening COPD
Dec 15, 2009 |
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A new study links chronic obstructive pulmonary disease, or COPD, with increased activity of cells that act as sentinels to activate the body's immune system.
Researchers work on vaccine to improve immune system in newborns
Dec 15, 2009 |
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As soon as babies are born, they are susceptible to diseases and infections, such as jaundice and e-coli. For up to a month, their immune systems aren't adequately developed to fight diseases. Although these infections are ...
Biological catch-22 prevents induction of antibodies that block HIV
Medicine & Health / HIV & AIDS
Dec 15, 2009 |
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Scientists seeking to understand how to make an AIDS vaccine have found the cause of a major roadblock. It turns out that the immune system can indeed produce cells with the potential to manufacture powerful HIV-blocking ...
Mechanism discovered by which body's cells encourage tuberculosis infection
Dec 10, 2009 |
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Scientists have discovered a signaling pathway that tuberculosis bacteria use to coerce disease-fighting cells to switch allegiance and work on their behalf. Epithelial cells line the airways and other surfaces ...
Study reveals H1N1 unexpected weakness
Dec 10, 2009 |
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The H1N1 influenza virus has been keeping a secret that may be the key to defeating it and other flu viruses as well.
