|
Raventoxin
Raventoxins are neurotoxins from the venom of the spider '' Macrothele raveni''. Sources Raventoxins are toxins from the venom of the spider ''Macrothele raveni''. This is a hairy spider, a member of the genus ''Macrothele'', that can be found in the hilly areas of Ningming County, Guangxi Province in China. Chemistry Six different types of raventoxin have been described, named raventoxin-I to VI.Zeng, Xiong-zhi, Liang, Song-ping Purification and Preliminary Toxic Research of Raventoxin-II, a Neurotoxic Peptide from the Venom of the Spider Macrothele raveni . Life Science Research. 2001 september; 5(3): 217-220.Zeng Xiong-zhi, Liang Song-ping. Purification and Preliminary Active Characterization of Raventoxin-V, a Novel Insecticidal Toxin Isolated from the Spider Macrothele Rraveni. Journal of Huaihua University. 2007-04Zhang Peng fei, Chen Ping, Xiao Shun yong, Liang Song ping.Purification, Characterization of Raventoxin-VI from the Venom of the Spider Macrothele raveni Life Sci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrothele Raveni
''Macrothele'' is a genus of mygalomorph spiders in the family Macrothelidae, and was first described by A. Ausserer in 1871. It is the only genus in the family Macrothelidae, and most species occur in Asia, from India to Japan, and Java, with five found in Africa, and two in Europe. The name is derived from Ancient Greek μακρός ("makro-"), meaning "big", and θηλή ("thele"), referring to the spinnerets. Description Spiders of this genus are fairly large, with females of some Chinese species ranging from in body length. Males are smaller, sometimes only half that length. Macrothelids can be distinguished from other mygalomorph spiders by their larger posterior sigillae on the sternum, and the arrangement of the rows of teeth on the margin of the chelicerae: larger front-facing margin and smaller rear-facing. These spiders build tube-webs or funnel-webs under rocks or logs, or in crevices in the ground. Taxonomy The genus ''Macrothele'' was erected by Anton Ausse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrothele
''Macrothele'' is a genus of mygalomorph spiders in the family Macrothelidae, and was first described by A. Ausserer in 1871. It is the only genus in the family Macrothelidae, and most species occur in Asia, from India to Japan, and Java, with five found in Africa, and two in Europe. The name is derived from Ancient Greek μακρός ("makro-"), meaning "big", and θηλή ("thele"), referring to the spinnerets. Description Spiders of this genus are fairly large, with females of some Chinese species ranging from in body length. Males are smaller, sometimes only half that length. Macrothelids can be distinguished from other mygalomorph spiders by their larger posterior sigillae on the sternum, and the arrangement of the rows of teeth on the margin of the chelicerae: larger front-facing margin and smaller rear-facing. These spiders build tube-webs or funnel-webs under rocks or logs, or in crevices in the ground. Taxonomy The genus ''Macrothele'' was erected by Anton Aussere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxin
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature nervous tissue.Olney 2002 The term can also be used to classify endogenous compounds, which, when abnormally contacted, can prove neurologically toxic. Though neurotoxins are often neurologically destructive, their ability to specifically target neural components is important in the study of nervous systems. Common examples of neurotoxins include lead, ethanol (drinking alcohol), glutamate,Choi 1987 nitric oxide, botulinum toxin (e.g. Botox), tetanus toxin,Simpson 1986 and tetrodotoxin. Some substances such as nitric oxide and glutamate are in fact essential for proper function of the body and only exert neurotoxic effects at excessive concentrations. Neurotoxins inhibit neuron control over ion concentrations across the cell membrane, or com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exophthalmos
Exophthalmos (also called exophthalmus, exophthalmia, proptosis, or exorbitism) is a bulging of the eye anteriorly out of the orbit. Exophthalmos can be either bilateral (as is often seen in Graves' disease) or unilateral (as is often seen in an orbital tumor). Complete or partial dislocation from the orbit is also possible from trauma or swelling of surrounding tissue resulting from trauma. In the case of Graves' disease, the displacement of the eye results from abnormal connective tissue deposition in the orbit and extraocular muscles, which can be visualized by CT or MRI. If left untreated, exophthalmos can cause the eyelids to fail to close during sleep, leading to corneal dryness and damage. Another possible complication is a form of redness or irritation called superior limbic keratoconjunctivitis, in which the area above the cornea becomes inflamed as a result of increased friction when blinking. The process that is causing the displacement of the eye may also compre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxins
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature nervous tissue.Olney 2002 The term can also be used to classify endogenous compounds, which, when abnormally contacted, can prove neurologically toxic. Though neurotoxins are often neurologically destructive, their ability to specifically target neural components is important in the study of nervous systems. Common examples of neurotoxins include lead, ethanol (drinking alcohol), glutamate,Choi 1987 nitric oxide, botulinum toxin (e.g. Botox), tetanus toxin,Simpson 1986 and tetrodotoxin. Some substances such as nitric oxide and glutamate are in fact essential for proper function of the body and only exert neurotoxic effects at excessive concentrations. Neurotoxins inhibit neuron control over ion concentrations across the cell membrane, or c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Channel Toxins
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MCF-7
MCF-7 is a breast cancer cell line isolated in 1970 from a 69-year-old White woman. MCF-7 is the acronym of Michigan Cancer Foundation-7, referring to the institute in Detroit where the cell line was established in 1973 by Herbert Soule and co-workers. The Michigan Cancer Foundation is now known as the Barbara Ann Karmanos Cancer Institute. Prior to MCF-7, it was not possible for cancer researchers to obtain a mammary cell line that was capable of living longer than a few months. The patient, Frances Mallon died in 1970. Her cells were the source of much of current knowledge about breast cancer. At the time of sampling, she was a nun in the convent of Immaculate Heart of Mary in Monroe, Michigan under the name of Sister Catherine Frances. MCF-7 and two other breast cancer cell lines, named T-47D and MDA-MB-231, account for more than two-thirds of all abstracts reporting studies on mentioned breast cancer cell lines, as concluded from a Medline-based survey. Characteristics of MC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, approximately twenty to thirty billion cells die per day. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysis
Lysis ( ) is the breaking down of the membrane of a cell, often by viral, enzymic, or osmotic (that is, "lytic" ) mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a ''lysate''. In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles. Many species of bacteria are subject to lysis by the enzyme lysozyme, found in animal saliva, egg white, and other secretions. Phage lytic enzymes (lysins) produced during bacteriophage infection are responsible for the ability of these viruses to lyse bacterial cells. Penicillin and related β-lactam antibiotics cause the death of bacteria through enzyme-mediated lysis that occurs after the drug causes the bacterium to form a defective cell wall. If the cell wall is completely lost and the penicillin was used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necrosis
Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated digestion of cell components. In contrast, apoptosis is a naturally occurring programmed and targeted cause of cellular death. While apoptosis often provides beneficial effects to the organism, necrosis is almost always detrimental and can be fatal. Cellular death due to necrosis does not follow the apoptotic signal transduction pathway, but rather various receptors are activated and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates in the surrounding tissue an inflammatory response, which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis. However, microbial damaging substances released by leukocytes would crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HeLa
HeLa (; also Hela or hela) is an immortalized cell line used in scientific research. It is the oldest and most commonly used human cell line. The line is derived from cervical cancer cells taken on February 8, 1951, named after Henrietta Lacks, a 31-year-old African-American mother of five, who died of cancer on October 4, 1951. The cell line was found to be remarkably durable and prolific, which allows it to be used extensively in scientific study. The cells from Lacks's cancerous cervical tumor were taken without her knowledge or consent, which was common practice in the United States at the time. Cell biologist George Otto Gey found that they could be kept alive, and developed a cell line. Previously, cells cultured from other human cells would only survive for a few days. Cells from Lacks's tumor behaved differently. History Origin In 1951, a patient named Henrietta Lacks was admitted to the Johns Hopkins Hospital with symptoms of irregular vaginal bleeding, and was s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
