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Cry1Ac Resistance
Cry1Ac protoxin is a crystal protein produced by the gram-positive bacterium, ''Bacillus thuringiensis'' (Bt) during sporulation. Cry1Ac is one of the delta endotoxins produced by this bacterium which act as insecticides. Because of this, the genes for these have been introduced into commercially important crops by genetic engineering (such as cotton and corn) in order to confer pest resistance on those plants. Transgenic Bt cotton initially expressed a single Bt gene, which codes for Cry1Ac. Subsequently, Bt cotton has added other delta endotoxins. Products such as Bt cotton, Bt brinjal and genetically modified maize have received attention due to a number of issues, including genetically modified food controversies, and the Séralini affair. Cry1Ac is also a mucosal adjuvant (an immune-response enhancer) for humans. It has been used in research to develop a vaccine against the amoeba ''Naegleria fowleri''. This amoeba can invade and attack the human nervous system and brain, ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoxin
Toxication, toxification or toxicity exaltation is the conversion of a chemical compound into a more toxic form in living organisms or in substrates such as soil or water. The conversion can be caused by enzymatic metabolism in the organisms, as well as by abiotic chemical reactions. While the parent drug is usually less active, both the parent drug and its metabolite can be chemically active and cause toxicity, leading to mutagenesis, teratogenesis, and carcinogenesis. Different classes of enzymes, such as P450 monooxygenases, epoxide hydrolase, or acetyltransferases can catalyze the process in the cell, mostly in the liver. Parent non-toxic chemicals are generally referred to as ''protoxins''. While toxication is generally undesirable, in certain cases it is required for the ''in vivo'' conversion of a prodrug to a metabolite with desired pharmacological or toxicological activity. Codeine is an example of a prodrug, metabolized in the body to the active compounds morphine and co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetically Modified Maize
Genetically modified maize ( corn) is a genetically modified crop. Specific maize strains have been genetically engineered to express agriculturally-desirable traits, including resistance to pests and to herbicides. Maize strains with both traits are now in use in multiple countries. GM maize has also caused controversy with respect to possible health effects, impact on other insects and impact on other plants via gene flow. One strain, called Starlink, was approved only for animal feed in the US but was found in food, leading to a series of recalls starting in 2000. Marketed products Herbicide-resistant maize Corn varieties resistant to glyphosate herbicides were first commercialized in 1996 by Monsanto, and are known as "Roundup Ready Corn". They tolerate the use of Roundup. Bayer CropScience developed "Liberty Link Corn" that is resistant to glufosinate. Pioneer Hi-Bred has developed and markets corn hybrids with tolerance to imidazoline herbicides under the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Amoebic Meningoencephalitis
Naegleriasis, also known as primary amoebic meningoencephalitis (PAM), is an almost invariably fatal infection of the brain by the free-living protozoan '' Naegleria fowleri''. Symptoms include headache, fever, nausea, vomiting, a stiff neck, confusion, hallucinations and seizures. Symptoms progress rapidly over around five days with characteristics of both meningitis and encephalitis, making it a type of meningoencephalitis. Death usually results within one to two weeks of symptom onset. ''N. fowleri'' is typically found in warm bodies of fresh water, such as ponds, lakes, rivers and hot springs. It is found in an amoeboid, temporary flagellate stage or microbial cyst in soil, poorly maintained municipal water supplies, water heaters, near warm-water discharges of industrial plants and in poorly chlorinated or unchlorinated swimming pools. There is no evidence of it living in salt water. As the disease is rare, it is often not considered during diagnosis. Although infec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naegleria Fowleri
''Naegleria fowleri'', also known as the brain-eating amoeba, is a species of the genus ''Naegleria''. It belongs to the phylum Percolozoa and is classified as an amoeboflagellate Excavata, excavate, an organism capable of behaving as both an amoeba and a flagellate. This free-living microorganism primarily feeds on bacteria, but can become pathogenic in humans, causing an extremely rare, sudden, severe, and almost always fatal brain infection known as naegleriasis or primary amoebic meningoencephalitis (PAM). It is typically found in warm freshwater bodies such as lakes, rivers, hot springs, warm water discharge from industrial or power plants, geothermal well water, and poorly maintained or minimally Water chlorination, chlorinated swimming pools with residual chlorine levels under 0.5 g/m3, water heaters, soil, and pipes connected to tap water. It can exist in either an amoeboid or temporary flagellate stage. Etymology The organism was named after Malcolm Fowler, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adjuvants, Immunologic
In immunology, an adjuvant is a substance that increases or modulates the immune response to a vaccine. The word "adjuvant" comes from the Latin word , meaning to help or aid. "An immunologic adjuvant is defined as any substance that acts to accelerate, prolong, or enhance antigen-specific immune responses when used in combination with specific vaccine antigens." In the early days of vaccine manufacture, significant variations in the efficacy of different batches of the same vaccine were correctly assumed to be caused by contamination of the reaction vessels. However, it was soon found that more scrupulous cleaning actually seemed to ''reduce'' the effectiveness of the vaccines, and some contaminants actually enhanced the immune response. There are many known adjuvants in widespread use, including potassium alum, various plant and animal derived oils and virosomes. Overview Adjuvants in immunology are often used to modify or augment the effects of a vaccine by stimulating the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mucous
Mucus (, ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is a viscous colloid containing inorganic salts, antimicrobial enzymes (such as lysozymes), immunoglobulins (especially IgA), and glycoproteins such as lactoferrin and mucins, which are produced by goblet cells in the mucous membranes and submucosal glands. Mucus covers the epithelial cells that interact with outside environment, serves to protect the linings of the respiratory, digestive, and urogenital systems, and structures in the visual and auditory systems from pathogenic fungi, bacteria and viruses. Most of the mucus in the body is produced in the gastrointestinal tract. Amphibians, fish, snails, slugs, and some other invertebrates also produce external mucus from their epidermis as protection against pathogens, to help in mov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Séralini Affair
The Séralini affair was the controversy surrounding the publication, retraction, and republication of a journal article by French molecular biologist Gilles-Éric Séralini. First published by ''Food and Chemical Toxicology '' in September 2012, the article presented a two-year feeding study in rats, and reported an increase in tumors among rats fed genetically modified corn and the herbicide RoundUp. Scientists and regulatory agencies subsequently concluded that the study's design was flawed and its findings unsubstantiated. A chief criticism was that each part of the study had too few rats to obtain statistically useful data, particularly because the strain of rat used, Sprague Dawley, develops tumors at a high rate over its lifetime. The publicity surrounding publication of the article also attracted criticism, with science writer Declan Butler calling it "a tightly orchestrated media offensive". As part of a news embargo, Séralini required journalists to sign an unusual c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetically Modified Food Controversies
Consumers, farmers, biotechnology, biotechnology companies, governmental regulators, non-governmental organizations, and scientists have been involved in controversies around foods and other goods derived from genetically modified crops instead of Plant breeding#Classical plant breeding, conventional crops, and other uses of genetic engineering in food production. The key areas of controversy related to genetically modified food (GM food or GMO food) are whether such food should be labeled, the role of government regulators, the objectivity of scientific research and publication, the effect of genetically modified crops on health and the environment, the effect on pesticide resistance, the impact of such crops for farmers, and the role of the crops in feeding the world population. In addition, products derived from GMO organisms play a role in the production of ethanol fuels and pharmaceuticals. Specific concerns include mixing of genetically modified and non-genetically modifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bt Brinjal
The genetically modified brinjal is a suite of transgenic brinjals (also known as eggplant or aubergine) created by inserting a crystal protein gene ('' Cry1Ac'') from the soil bacterium ''Bacillus thuringiensis'' into the genome of various brinjal cultivars. The insertion of the gene, along with other genetic elements such as promoters, terminators and an antibiotic resistance marker gene into the brinjal plant is accomplished using ''Agrobacterium''-mediated genetic transformation. The Bt brinjal has been developed to give resistance against lepidopteron insects, in particular, the Brinjal Fruit and Shoot Borer ('' Leucinodes orbonalis'')(FSB), by forming pores in the insects' digestive system. Mahyco, an Indian seed company based in Jalna, Maharashtra, has developed the Bt brinjal. The genetically modified brinjal event is termed Event EE 1, and Mahyco has also applied for approval of two brinjal hybrids. Event EE 1 was introduced by breeding the plants into various local v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive Bacteria
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain is used by microbiologists to place bacteria into two main categories, gram-positive (+) and gram-negative (−). Gram-positive bacteria have a thick layer of peptidoglycan within the cell wall, and gram-negative bacteria have a thin layer of peptidoglycan. Gram-positive bacteria retain the crystal violet stain used in the test, resulting in a purple color when observed through an optical microscope. The thick layer of peptidoglycan in the bacterial cell wall retains the stain after it has been fixed in place by iodine. During the decolorization step, the decolorizer removes crystal violet from all other cells. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bt Cotton
Bt cotton is a genetically modified pest resistant plant cotton variety that produces an insecticide to combat bollworm. Description Strains of the bacterium ''Bacillus thuringiensis'' produce over 200 different Bt toxins, each harmful to different insects. Most notably, Bt toxins are insecticidal to the larvae of moths and butterflies, beetles, cotton bollworms and flies but are harmless to other forms of life. The gene coding for Bt toxin has been inserted into cotton as a transgene, causing it to produce this natural insecticide in its tissues. In many regions, the main pests in commercial cotton are lepidopteran larvae, which are killed by the Bt protein in the genetically modified cotton they eat. This eliminates the need to use large amounts of broad-spectrum insecticides to kill lepidopteran pests (some of which have developed pyrethroid resistance). This spares natural insect predators in the farm ecology and further contributes to noninsecticide pest management. Bt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Engineering
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of Genetic engineering techniques, technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by Artificial gene synthesis, artificially synthesising the DNA. A Vector (molecular biology), construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the Lambda phage, lambda virus. As well as inserting genes, the process can be used to remove, or "Gene knockout, knock out", genes. The new DNA can either be inserted randomly or Gene targeting, targeted to a spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
