Cytotoxicity is the quality of being toxicity toxic to cell biology cell s. Examples of toxic agents are a chemical substance , an immune cell or some types of venom e.g. from the Bitis arietans puff adder or brown recluse spider . Cell physiology Treating cells with a cytotoxic compound can result in a variety of cell fates. The cells may undergo necrosis , in which they lose membrane integrity and die rapidly as a result of cell lysis . The cells can stop actively growing and dividing a decrease in cell viability , or the cells can activate a genetic program of controlled cell death apoptosis . Cells undergoing necrosis typically exhibit rapid swelling, lose membrane integrity, shut down metabolism and release their contents into the environment. Cells that undergo rapid necrosis in vitro do not have sufficient time or energy to activate apoptotic machinery and will not express apoptotic markers. ref name viability Promega Corporation 2006 http www.promega.com paguide chap4.htm Protocols ... time, dose of toxin, and plating density in cell based cytotoxicity assays journal Assay ... url ref Measuring cytotoxicityCytotoxicity assays are widely used by the pharmaceutical industry to screen for cytotoxicity in compound libraries. Researchers can either look for cytotoxic ... method for the quantitation of lactate dehydrogenase release in measurements of cellular cytotoxicity ... ref Cytotoxicity can also be monitored using the MTT assay MTT or MTS assay. This assay measures the reducing ... 5 issue 1 pages 127 36 year 2007 month February pmid 17355205 doi 10.1089 adt.2006.053 url ref Cytotoxicity ... assays. Immune system cytotoxicity Antibody dependent cell mediated cytotoxicity ADCC describes ... . Lymphocyte mediated cytotoxicity , on the other hand, does not have to be mediated by antibodies nor does complement dependent cytotoxicity CDC , which is mediated by the complement system ... Cytotoxicity Assays, Promega Corporation Category Toxicology Category Immunology de Zytotoxizit t ... more details
Antibody Dependent Cell Mediated Cytotoxicity ADCC is a mechanism of cell mediated immunity whereby an effector cell of the immune system actively lysis lyses a target cell that has been bound by specific antibodies . It is one of the mechanisms through which antibodies, as part of the humoral immunity humoral immune response , can act to limit and contain infection. Classical ADCC is mediated by natural killer cell natural killer NK cells neutrophils and eosinophil s can also mediate ADCC. For example, eosinophils can kill certain parasitic worms known as helminth s through ADCC. ADCC is part of the adaptive immune system adaptive immune response due to its dependence on a prior antibody response. ADCC by NK cells The typical ADCC involves activation of NK cells by antibodies. An NK cell s Fc receptor recognizes the Fc portion of an antibody , such as IgG , which has bound to the surface of a pathogen infected target cell. The most common Fc receptor on the surface of an NK Cell is called CD16 or Fc RIII. Once the Fc receptor binds to the Fc region of IgG, the Natural Killer cell releases cytokines such as interferon Type II IFN IFN , and cytotoxic granules containing perforin and granzymes that enter the target cell and promote cell death by triggering apoptosis . This is similar to, but independent of, responses by cytotoxic T cell s CTLs . ADCC by eosinophils Large parasite s like helminth s are too big to be engulfed and killed by phagocytosis . They also have an external structure or integument that is resistant to attack by substances released by neutrophil s and macrophage s. However, an antibody called IgE can coat these parasites. The Fc receptor FceRI of an eosinophil can then recognize IgE. The interaction between FceRI and the Fc portion of helminth bound IgE causes the eosinophil to degranulate. ADCC in vitro Several laboratory methods exist for determining ... Notes MeshName Antibody Dependent Cell Cytotoxicity Hypersensitivity and autoimmune diseases ... more details
Cytotoxic T lymphocytes CTLs are generated by immune activation of cytotoxic T cells T sub c sub cells . They are generally CD8 sup sup , which makes them MHC class I restricted. CTLs are able to eliminate most cells in the body since most nucleated cells express class I MHC molecules. The CTL mediated immune system can be divided into two phases. In the first phase, functional effector CTLs are generated from naive T sub c sub cells through activation and differentiation. In the second phase, effector CTLs destroy target cells by recognizing the antigen MHC class I complex. Phase 1 In phase one, effector CTLs are generated from CTL precursors. The CTL precursors include naive T sub c sub cells since they are incapable of killing target cells. After a precursor cell has been activated, it can then differentiate into a functional CTL with cytotoxic activity. There are three sequential signals that are required to complete this process. First, there is TCR recognition of the peptide MHC class I complex. This step allows the cell to become licensed to an antigen presenting cell . Second, a costimulatory signal is transmitted by the interaction between CD28 and B7 of the precursor cell and the licensed antigen presenting cell. Last, a signal is induced by the interaction between IL 2 and the high affinity IL 2 receptor . This results in proliferation and differentiation of the antigen activated precursor cell into a functional effector CTL. Phase 2 In phase two, the now functional effector CTLs destroy the target cells. This can be done in two ways. These pathways are the cytotoxic protein pathway and the Fas ligand pathway. Apoptosis is the primary mechanism for both of these pathways. Cytotoxic Protein Pathway One pathway is the cytotoxic protein pathway. In this pathway perforins and granzymes are taken up by the target cell. In this pathway, the perforins facilitate the entry of granule contents into the cell. The granzymes then active the endogenous apoptosis pathw ... more details
ADCC may refer to ADCC Submission Wrestling World Championship ADCC Abu Dhabi Combat Club Submission Wrestling Championship Antibody dependent cellular cytotoxicity Air Defence Cadet Corps Viking ADCC Viking Line cruiseferry disambig Category Initialisms de ADCC fr ADCC ja ADCC pl ADCC ... more details
orphan date February 2009 The first contact of a T cell T or B cell with its specific antigen is called priming and causes differentiation into Effector T cells effector T or Effector B cell B cells Cytotoxicity cytotoxic , cytokine , antibody . Category Immunology Priming immunology stub ... more details
Unreferenced auto yes date December 2009 Orphan date February 2009 Ultraz is a Fluoroelastomeric compound developed by Aquasyn specifically for the Biopharmaceutical industry. A base resistant compound with excellent steam resistance, Ultraz performance far exceeds the baselines of EPDM or PTFE. It is typically used as a membrane material in Hygienic Diaphragm Valves . In Biological applications with periodic steam sterilization requirements, Ultraz is the optimal material for the combined temperature resistance of PTFE and the flexibility of EPDM. USP class VI, cytotoxicity and heavy metals tests have been performed with its use in industry for almost ten years. It is low protein binding, flexible and temperature resistant. Category Fluoropolymers Chemistry stub ... more details
PBB geneid 9437 Natural cytotoxicity triggering receptor 1 is a protein that in humans is encoded by the NCR1 gene . ref name pmid9730896 cite journal author Pessino A, Sivori S, Bottino C, Malaspina A, Morelli L, Moretta L, Biassoni R, Moretta A title Molecular cloning of NKp46 a novel member of the immunoglobulin superfamily involved in triggering of natural cytotoxicity journal J Exp Med volume 188 issue 5 pages 953 60 year 1998 month Sep pmid 9730896 pmc doi 10.1084 jem.188.5.953 ref ref name entrez cite web title Entrez Gene NCR1 natural cytotoxicity triggering receptor 1 url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 9437 accessdate ref NCR1 has also been designated as CD335 cluster of differentiation 335 . The PBB Summary template is automatically maintained by Protein Box Bot. See Template PBB Controls to Stop updates. PBB Summary section title summary text References reflist Further reading refbegin 2 PBB Further reading citations cite journal author Biassoni R, Cantoni C, Marras D, et al. title Human natural killer cell receptors insights into their molecular function and structure. journal J. Cell. Mol. Med. volume 7 issue 4 pages 376 87 year 2004 pmid 14754506 doi 10.1111 j.1582 4934.2003.tb00240.x cite journal author Sivori S, Vitale ... cytotoxicity receptors in human natural killer cells. journal Eur. J. Immunol. volume 33 issue ... and functionally associated with natural cytotoxicity receptors and activates human NK cell mediated cytotoxicity. journal Eur. J. Immunol. volume 33 issue 12 pages 3367 76 year 2004 pmid 14635045 doi ..., and natural cytotoxicity receptors regulate multiple myeloma cell recognition by natural killer ... killer NK cell surface expression and function of human natural cytotoxicity receptors NKp46 ... NK cells role of natural cytotoxicity receptors. journal J. Immunol. volume 174 issue 5 pages 2653 ... of the heparin heparan sulfate binding site of the natural cytotoxicity receptor NKp46 ... more details
PBB geneid 259197 Natural cytotoxicity triggering receptor 3 is a protein that in humans is encoded by the NCR3 gene . ref name pmid8824804 cite journal author Nalabolu SR, Shukla H, Nallur G, Parimoo S, Weissman SM title Genes in a 220 kb region spanning the TNF cluster in human MHC journal Genomics volume 31 issue 2 pages 215 22 year 1997 month Mar pmid 8824804 pmc doi 10.1006 geno.1996.0034 ref ref name pmid11782277 cite journal author Sato M, Ohashi J, Tsuchiya N, Tadokoro K, Juji T, Hanaoka K, Tokunaga K, Yabe T title Identification of novel single nucleotide substitutions in the NKp30 gene expressed in human natural killer cells journal Tissue Antigens volume 58 issue 4 pages 255 8 year 2002 month Jan pmid 11782277 pmc doi 10.1034 j.1399 0039.2001.580406.x ref ref name entrez cite web title Entrez Gene NCR3 natural cytotoxicity triggering receptor 3 url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 259197 accessdate ref NCR3 has also been designated as CD337 cluster of differentiation 337 . The PBB Summary template is automatically maintained by Protein Box Bot. See Template PBB Controls to Stop updates. PBB Summary section title summary text References reflist Further reading refbegin 2 PBB Further reading citations cite journal author Djeu JY, Jiang K, Wei S title A view to a kill signals triggering cytotoxicity. journal Clin. Cancer Res ... triggering receptor involved in natural cytotoxicity mediated by human natural killer cells ... NK cells to mediate cytotoxicity. journal Proc. Natl. Acad. Sci. U.S.A. volume 99 issue 26 pages 16963 ... R, Parolini S, Castriconi R, et al. title Selective cross talk among natural cytotoxicity receptors ..., Falco M, et al. title CD59 is physically and functionally associated with natural cytotoxicity receptors and activates human NK cell mediated cytotoxicity. journal Eur. J. Immunol. volume 33 issue 12 ..., Negrini S, et al. title Tumor induced apoptosis of human IL 2 activated NK cells role of natural cytotoxicity ... more details
PBB geneid 9436 Natural cytotoxicity triggering receptor 2 is a protein that in humans is encoded by the NCR2 gene . ref name pmid10049942 cite journal author Cantoni C, Bottino C, Vitale M, Pessino A, Augugliaro R, Malaspina A, Parolini S, Moretta L, Moretta A, Biassoni R title NKp44, a triggering receptor involved in tumor cell lysis by activated human natural killer cells, is a novel member of the immunoglobulin superfamily journal J Exp Med volume 189 issue 5 pages 787 96 year 1999 month Jun pmid 10049942 pmc 2192947 doi 10.1084 jem.189.5.787 ref ref name entrez cite web title Entrez Gene NCR2 natural cytotoxicity triggering receptor 2 url http www.ncbi.nlm.nih.gov sites entrez?Db gene&Cmd ShowDetailView&TermToSearch 9436 accessdate ref NCR2 has also been designated as CD336 cluster of differentiation 336 . The PBB Summary template is automatically maintained by Protein Box Bot. See Template PBB Controls to Stop updates. PBB Summary section title summary text References reflist Further reading refbegin 2 PBB Further reading citations cite journal author Hershkovitz O, Jivov S, Bloushtain N, et al. title Characterization of the recognition of tumor cells by the natural cytotoxicity receptor, NKp44. journal Biochemistry volume 46 issue 25 pages 7426 36 year 2007 pmid 17536787 doi 10.1021 bi7000455 cite journal author Forte P, Lilienfeld BG, Baumann BC, Seebach JD title Human NK cytotoxicity against porcine cells is triggered by NKp44 and NKG2D. journal J. Immunol. volume 175 issue 8 pages 5463 70 year 2005 pmid 16210654 doi cite journal author Fuchs A, Cella M, Kondo T, Colonna M title Paradoxic inhibition of human natural interferon producing cells by the activating receptor ... of human IL 2 activated NK cells role of natural cytotoxicity receptors. journal J. Immunol. volume ... NK cell receptor NKp44, a triggering partner in natural cytotoxicity. journal Structure volume 11 ... Augugliaro R, Parolini S, Castriconi R, et al. title Selective cross talk among natural cytotoxicity ... more details
Orphan date January 2011 File Agelasimine A.svg thumb 100px right Chemical structure of agelasimine A Agelasimines are a group of adenine related bicyclic terpenoid diterpenoids isolated from the orange sea sponge sponge Agelas mauritania . Their chemical structures are closely related to the agelasine s. Both groups of compounds display a range of biological activities, such as cytotoxicity, inhibition of adenosine transfer into rabbit erythrocyte s red blood cells , Ca sup 2 sup channel antagonistic action, Alpha 1 adrenergic receptor 1 adrenergic blockade and others. Both compounds have been reproduced in the laboratory by organic synthesis . References Fathi Afshar R Allen T M Krueger C A Cook D A Clanachan A S Vriend R Baer H P Cass C E, Canadian Journal of Physiology and Pharmacology , 1989, 67 4 , 276 81 Fathi Afshar, R. Allen, T. M., Canadian Journal of Chemistry , 1988, 66 1 , 45 50. Fathi Afshar, R. Allen, T. M. Krueger, C. A. Cook, D. A. Clanachan, A. S. Vriend, R. Baer, H. P. Cass, C. E., Canadian Journal of Physiology and Pharmacology , 1989, 67 4 , 276 81. Ohba, Masashi Iizuka, Kazuaki Ishibashi, Hiroyuki Fujii, Tozo., Tetrahedron journal Tetrahedron 1997, 53 50 , 16977 16986. Category Terpenes and terpenoids organic compound stub ... more details
Orphan date February 2009 Cruentaren is a macrolide secreted by the myxobacteria Byssovorax cruenta . Two isomer s A and B have been isolated with a molecular formula of C33H51 NO8 and molecular weight 589. Cruentaren A strongly inhibits the growth of yeast s and filamentous fungi , and inhibits the proliferation of different cancer cell lines including a multidrug resistant KB line. Cruentaren B shows only marginal cytotoxicity and no antifungal activity. References cite journal journal Journal of Antibiotics issn 0021 8820 year 2006 volume 59 issue 10 title Cruentaren, a new antifungal salicylate type macrolide from Byssovorax cruenta Myxobacteria with inhibitory effect on mitochondrial ATPase activity Fermentation and biological properties pages 664 668 last Kunze first Brigitte coauthors Heinrich Steinmetz, Gerhard H fle, Markus Huss, Helmut Wieczorek, Hans Reichenbach doi 10.1038 ja.2006.89 pmid 17191683 cite web title Cruentaren A, a highly cytotoxic benzolactone from Myxobacteria is a novel selective inhibitor of mitochondrial F1 ATPases url http www.sciencedirect.com science? ob ArticleURL& udi B6T36 4P3TVGJ 6& user 10& rdoc 1& fmt & orig search& sort d&view c& acct C000050221& version 1& urlVersion 0& userid 10&md5 44e6dd6b0348e86ea27d02c0cbdb0f7e publisher ScienceDirect accessdate 2008 07 07 Category Macrolides Category Antifungals ... more details
A macrophage activating factor MAF is a lymphokine that primes macrophage s to become Cytotoxicity cytotoxic to tumor s. It also controls the expression of Ia antigen s on the macrophage cell surface. ref name pmid12554797 cite journal author Mosser DM title The many faces of macrophage activation journal J. Leukoc. Biol. volume 73 issue 2 pages 209 12 year 2003 month February pmid 12554797 doi 10.1189 jlb.0602325 url issn ref Examples Interferon gamma Interleukin 4 Gc MAF ref name pmid19031451 cite journal author Yamamoto N, Ushijima N, Koga Y title Immunotherapy of HIV infected patients with Gc protein derived macrophage activating factor GcMAF journal J. Med. Virol. volume 81 issue 1 pages 16 26 year 2009 month January pmid 19031451 doi 10.1002 jmv.21376 url issn ref References Reflist External links MeshName Macrophage Activating Factors immunology stub Category Cytokines ... more details
Drugbox verifiedrevid IUPAC name 5 1,3 benzodioxol 5 ylmethyl 2 2 5 methyl 1H imidazol 4 yl methyl sulfanyl ethyl amino pyrimidin 4 3H one image Oxmetidine structure.png width CAS number 72830 39 8 CASNo Ref cascite ATC prefix ATC suffix ATC supplemental PubChem 51710 DrugBank ChemSpiderID 46799 C 19 H 21 N 5 O 3 S 1 molecular weight 399.47 g mol synonyms bioavailability metabolism elimination half life excretion pregnancy category legal status routes of administration smiles O C 1NC N C C 1Cc2ccc3OCOc3c2 NCCSCc4ncnc4C Oxmetidine is a H2 antagonist H2 receptor antagonist . ref name Wilson cite journal last Willson first R. A. coauthors Hall, T Hart, J. date 24 October 1987 title Oxmetidine H2 receptor antagonist induced cytotoxicity in isolated rat hepatocytes journal Journal of Applied Toxicology pmid 2902116 volume 8 issue 3 pages 223 225 doi 10.1002 jat.2550080311 ref References reflist Histaminergics Category H2 receptor antagonists drug stub ... more details
drugbox verifiedrevid 414095501 type mab image mab type mab source zu o target HER2 neu MGAH22 is the experimental name of an anti HER2 neu HER2 neu targeting monoclonal antibody developed by MacroGenics. Its mechanism of action is similar to the monoclonal antibody trastuzumab . Mechanism of Action A Fc domain optimized IgG monoclonal antibody directed against the human epidermal growth factor receptor 2 HER2 with potential immunomodulating and antineoplastic activities. After binding to HER2 on the tumor cell surface, anti HER2 monoclonal antibody MGAH22 may induce an ADCC antibody dependent cell mediated cytotoxicity ADCC against tumor cells overexpressing HER2. HER2, a tyrosine kinase receptor , is overexpressed by many cancer cell types. Compared to other anti HER2 monoclonal antibodies, the Fc domain of MGAH22 is optimized with increased binding to the activating CD16a Fcgamma receptor IIIA CD16A , expressed on cells such as NK cells natural killer NK cells and macrophages, thereby mediating an enhanced ADCC the Fc domain also shows decreased binding to the CD32B inhibitory Fcgamma receptor IIB CD32B . It is currently in Phase I clinical trial. External links http www.macrogenics.com products MGAH22 HER2.html http clinicaltrials.gov ct2 show NCT01148849 Category Monoclonal antibodies ... more details
chembox verifiedrevid 400101562 ImageFile Geiparvarin.svg ImageSize IUPACName 7 2 E 3 5,5 dimethyl 4 oxo 4,5 dihydrofuran 2 yl but 2 en 1 yl oxy 2 H chromen 2 one OtherNames Section1 Chembox Identifiers CASNo 36413 91 9 PubChem 5910585 SMILES CC CCOC1 CC2 C C C1 C CC O O2 C3 CC O C O3 C C MeSHName Geiparvarin Section2 Chembox Properties Formula C sub 19 sub H sub 18 sub O sub 5 sub MolarMass 326.343 g mol Appearance Density MeltingPt BoilingPt Solubility Section3 Chembox Hazards MainHazards FlashPt Autoignition Geiparvarin is a coumarin derivative found in the leaves of the Australian Willow Geijera Geijera parviflora . ref cite journal author Lahey FN, Macleod JK title The coumarins of Geijera parviflora Lindl journal Aust J Chem volume 20 issue 9 pages 1943 55 month September year 1967 doi 10.1071 CH9671943 ref It is a monoamine oxidase inhibitor . ref name pmid12443774 cite journal author Carotti A, Carrieri A, Chimichi S, et al. title Natural and synthetic geiparvarins are strong and selective MAO B inhibitors. Synthesis and SAR studies journal Bioorg. Med. Chem. Lett. volume 12 issue 24 pages 3551 5 year 2002 month December pmid 12443774 doi 10.1016 S0960 894X 02 00798 9 url http linkinghub.elsevier.com retrieve pii S0960894X02007989 ref Several analog chemistry analogue s of geiparvarin have been studied for antitumor properties. ref cite journal author Baraldi PG, Guarneri M, Manfredini S, Simoni D, Balzarini J, De Clercq E title Synthesis and cytostatic activity of geiparvarin analogues journal Journal of Medicinal Chemistry J Med Chem volume 32 issue 2 pages 284 8 year 1989 month February pmid 2913291 doi 10.1021 jm00122a002 url ref ref cite journal author Valenti P, Rampa A, Recanatini M, et al. title Synthesis, cytotoxicity and SAR of simple geiparvarin analogues journal Anticancer Drug Des volume 12 issue 6 pages 443 51 year 1997 month September pmid 9311554 doi url ref ref cite journal author Viola G, Vedaldi D, dall Acqua F, et al. title Synthesis, cyt ... more details
Unreferenced date April 2008 In Biomaterials Testing , a cell culture assay is any method which is used to assess the cytotoxicity of a material. This refers to the in vitro assessment of material to determine whether it releases toxic chemicals in sufficient quantities to kill cells either directly or indirectly through the inhibition of cell metabolic pathways. Cell culture evaluations are the precursor to whole animal studies and are a way to determine if significant cytotoxicity exists for the given material. Cell culture assays are standardized by ASTM , ISO , and BSI British Standards Institution . Methods How to date September 2009 Direct contact method A near confluent layer of fibroblasts are prepared in a culture plate Old cell culture media agar generally is removed Fresh media is added Material being tested is placed onto the cultures, which are incubated for 24 hours at 37 degrees Celsius The material is removed The culture media is removed The remaining cells are fixed and stained, dead cells are lost during fixation and only the live cells are stained The toxicity of the material is indicated by the absence of stained cells around the material Agar diffusion method A near confluent layer of fibroblasts are prepared in a culture plate Old cell culture media is removed The cells are covered with a solution of 2 agar, which often contains red vital stain When the agar solidifies the cells will have dispersed throughout its volume The material is then placed on the surface of the agar and incubated for 24 hours at 37 degrees Celsius Live cells take up the vital stain and retain it, dead cells do not The toxicity of the material is evaluated by the loss of vital stain under and around the material Surface microscopy is also needed to evaluate the material cell interface Elution method A near confluent layer of fibroblasts are prepared in a culture plate An extract of the material which is being tested is prepared using physiological saline or serum free me ... more details
and is associated with effective Antibody dependent cellular cytotoxicity ADCC Antibody dependent cell mediated cytotoxicity . It was shown to initiate ADCC in vitro, PMN have to adhere to their target ... more details
For the Inuyasha character My ga taxobox name Myoga image Mioga.jpg image caption Zingiber mioga regnum Plantae unranked divisio Angiosperms unranked classis Monocots unranked ordo Commelinids ordo Zingiberales familia Zingiberaceae genus Zingiber species Z. mioga binomial Zingiber mioga binomial authority Carl Peter Thunberg Thunb. William Roscoe Roscoe My ga or myoga ginger Zingiber mioga , Zingiberaceae is an herbaceous, deciduous, Perennial plant perennial native to Japan and southern part of Korea that is grown for its edible flower buds and flavorful shoots. Flower buds are finely shredded and used in Japanese cuisine as a garnish for miso soup, sunomono and dishes such as roasted eggplant. In Korean cuisine flower buds are skewered alternately with pieces of meat and then are pan fried. A traditional crop in Japan , myoga has been introduced to cultivation in Australia and New Zealand for export to the Japanese market. As a woodland plant myoga has specific shade requirements for its growth. It is frost tolerant to 0F, 18C possibly colder. Medicinal Properties While some constituents of myoga are Cytotoxicity cytotoxic , others have shown promise for potentially Carcinogen anti carcinogenic properties. http www.liebertonline.com doi pdf 10.1089 ars.2005.7.1621 Cultural references There is an old saying in Japan that eating too much myoga makes you forgetful or stupid. Citation needed date November 2010 External links More info and pics about myoga from the blog http scentofgreenbananas.blogspot.com 2005 02 myoga.html the scent of green bananas wikispecies Zingiber mioga Myoga Category Inflorescence vegetables Category Japanese cuisine Category Stem vegetables Category Zingiberaceae vegetable stub Zingiberales stub az Yapon z nc fili es Zingiber mioga eo Miogo fr Zingiber mioga ko la Zingiber mioga ja pl Imbir japo ski pt Zingiber mioga vi My ga zh ... more details
Infobox Anatomy Name PAGENAME Latin GraySubject GrayPage Image Germinal epithelium testicle.svg Caption Germinal epithelium of the testicle . 1 basal lamina , 2 spermatogonia , 3 spermatocyte 1st order, 4 spermatocyte 2nd order, 5 spermatid , 6 mature spermatid, 7 Sertoli cell , 8 tight junction blood testis barrier Image2 Caption2 Precursor System Artery Vein Nerve Lymph MeshName MeshNumber DorlandsPre DorlandsSuf The blood testis barrier abbreviated as BTB is a physical barrier between the blood vessel s and the seminiferous tubule s of the animal testicle testes . The barrier is formed by tight connections between the Sertoli cell s, which are sustentacular cell s supporting cells of the seminiferous tubules , and nourish the Spermatogonium spermatogonia . The barrier prevents passage of cytotoxicity cytotoxic agents bodies or substances that are toxicity toxic to cell biology cell s into the seminiferous tubules. Auto immune response The blood testes barrier can be damaged by trauma to the testes including torsion or impact , by surgery or as a result of vasectomy . When the blood testes barrier is breached, and sperm enters the bloodstream, the immune system mounts an autoimmune response against the sperm. The anti sperm antibody antibodies generated by the immune system can bind to various antigen ic sites on the surface of the sperm. If they bind to the head, the sperm may be less able to fertilize an ovum egg , and if they bind to the tail, the motility of the sperm can be reduced. See also Blood brain barrier Spermatogenesis External links MeshName Blood testis barrier http www.cvm.okstate.edu instruction mm curr histology MR HiMRP4.htm Overview at okstate.edu circulatory stub genitourinary stub Male reproductive system Category Reproductive system Category Animal physiology de Blut Hoden Schranke it Barriera emato testicolare ja nds Blood Kl ten Hinnern pl Bariera krew j dro ru zh ... more details
Antibody opsonization is the process by which a pathogen is marked for ingestion and destruction by a phagocyte . Opsonization involves the binding of an opsonin , i.e., antibody , to a receptor on the pathogen s cell membrane ref http cancerweb.ncl.ac.uk cgi bin omd?query opsonisation Definition opsonization from Online Medical Dictionary Bot generated title ref . After opsonin binds to the membrane, phagocytes are attracted to the pathogen. The Fab portion of the antibody binds to the antigen, whereas the Fc portion of the antibody binds to an Fc receptor on the phagocyte, facilitating phagocytosis. ref Parham, P. 2005 . The Immune System, Garland Science Publishing, New York, NY. ref The receptor opsin complex can also create byproducts like C3b and C4b which are important components of the complement system . These components are deposited on the cell surface of the pathogen and aid in its destruction ref Kumar, V., Abbas, A. K., & Fausto, N. 2005 . Pathologic basis of disease. Philadelphia Elsevier Saunders ref . The cell can also be destroyed by a process called antibody dependent cellular cytotoxicity , in which the pathogen does not need to be phagocytosed to be destroyed. During this process, the pathogen is opsonized and bound with the antibody IgG via its Fab domain. Then the antibody binds an immune effector cell via its Fc domain and this binding triggers a release of lysis products from the bound immune effector cell monocytes, neutrophils, eosinophils and natural killer cells . This process can cause inflammation of surrounding tissues and damage to healthy cells. References Reflist DEFAULTSORT Antibody Opsonization Category Immune system immunology stub ca Opsonitzaci de Opsonisierung es Opsonizaci n eu Opsonizazio nl Opsonisatie nds Opsoniseeren pl Opsonizacja pt Opsoniza o ru sv Opsonisering ... more details
Radiation poisoning Experiments in radiation biology have found that as the absorbed dose of radiation increases, the number of Cell biology cells which survive decreases. They have also found that if the radiation is fractionated into smaller Gray unit doses , with one or more rest periods in between, fewer cells cell death die . This is because of self repair mechanisms which repair the damage to DNA http users.rcn.com jkimball.ma.ultranet BiologyPages D DNArepair.html http www.benbest.com lifeext aging.html dna and other biomolecules such as proteins . These mechanisms can be over expressed in cancer cells, so caution should be used in using results for a cancer cell line to make predictions for healthy cells if the cancer cell line is known to be resistant to Cytotoxicity cytotoxic drugs such as cisplatin . The DNA repair DNA self repair processes in some organisms is exceptionally good for instance, the bacterium Deinococcus radiodurans can tolerate a 15 000 Gy 1.5 MRad dose. In the graph below, called a Cell survival curve , the dose vs. surviving fraction have been drawn for a hypothetical group of cells with and without a rest time for the cells to recover. Other than the recovery time partway through the irradiation, the cells would have been treated identically. Image Effectofselfrepair.png center 600px This is a graph showing the effect of fractionation on the ability of gamma rays to cause cell death. The blue line is for cells which were not given a chance to recover the red line is for cells which were allowed to stand for a time and recover. The human body contains many types of cells, and the human can be killed by the loss of a single type of cells in a vital Organ anatomy organ . For many short term radiation deaths due to what is commonly known as radiation sickness 3 days to 30 days after exposure , it is the loss of bone marrow cells which produce blood cells , and the loss of other cells in the wall of the intestines , which is f ... more details
Tissue typing is a procedure in which the tissues of a prospective donor and recipient are tested for compatibility prior to Organ transplant transplantation . An embryo can be tissue typed to ensure that the embryo implanted can be a cord blood stem cell donor for a sick sibling. ref Designing Donors . Shaun D. Pattinson, Faculty of Law and Sheffield Institute of Biotechnological Law and Ethics, University of Sheffield. http www.ccels.cf.ac.uk literature issue 2003 pattinson.pdf link ref One technique of tissue typing, mixed leukocyte reaction , is performed by culturing lymphocytes from the donor together with those from the recipient. ref http pathmicro.med.sc.edu ghaffar mhc2000.htm MHC Bot generated title ref Another technique, known as a micro cytotoxicity assay, utilizes serum with known anti HLA antibodies that recognize particular human leukocyte antigen HLA loci HLA A, HLA B, HLA C, HLA DP, HLA DQ, HLA DR in order to match genetically similar individuals in hopes of performing a tissue transplantation. In this technique a donor s blood cells are major histocompatibility complex MHC typed by mixing them with Blood serum serum containing the anti HLA antibodies . If the antibodies recognize their epitope on the MHC then classical complement pathway complement activation occurs and the cell will be osmotically lysis lysed . Lysis results in the cell taking up a dye trypan blue . This allows identification of cell s MHC indirectly based on the specificity of the known antibodies in the serum. See also Histocompatibility References references External links http www.hfea.gov.uk preimplantation tissue typing.html How Preimplantation tissue typing works, HFEA website MeshName Tissue typing http www.stanford.edu dept HPS transplant html tt 1.html http www.bchealthguide.org kbase topic medtest hw40261 descrip.htm Category Medical tests Category Transplantation medicine immunology stub ... more details
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