The Experts below are selected from a list of 43023 Experts worldwide ranked by ideXlab platform
James L. Zehnder - One of the best experts on this subject based on the ideXlab platform.
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prozone effect in the diagnosis of lupus anticoagulant for the lupus anticoagulant hypoprothrombinemia syndrome
American Journal of Clinical Pathology, 2016Co-Authors: Jing Jin, James L. ZehnderAbstract:Objectives: The main clinical sequela of a lupus anticoagulant is increased thrombosis risk. However, bleeding due to lupus anticoagulant-hypoprothrombinemia syndrome is a rare but well-described manifestation of antiphospholipid syndrome. The association of acute acquired hypoprothrombinemia is caused by a lupus anticoagulant’s specificity to prothrombin, which results in clearance of prothrombin and bleeding due to hypoprothrombinemia (usually <10% of normal). Severe life-threatening bleeding is most frequently reported in children with systemic lupus erythematosus or in healthy children after viral infection. In such cases, steroid therapy is usually effective in controlling the bleeding problems and improving prothrombin levels. Methods: We report one pediatric patient with a lupus anticoagulant who had acute hemorrhagic diathesis. Results: The diagnosis in this case was complicated by the presence of a prozone effect in lupus anticoagulant testing. The prozone effect (also known as hook effect) refers to situations where very high concentrations of antibody mask detection, typically in Antigen-Antibody Reactions, which depend on visualization of agglutination. Decreasing the antibody/antigen ratio results in detectable Antigen-Antibody complexes. Conclusions: We report for the first time a variation on this theme in a patient with a lupus anticoagulant-type antiphospholipid antibody and hypoprothrombinemia, which corrected with immunosuppression and restoration of normal prothrombin levels.
Eiichi Tamiya - One of the best experts on this subject based on the ideXlab platform.
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RNA aptamer-based optical nanostructured sensor for highly sensitive and label-free detection of Antigen-Antibody Reactions.
Analytical and Bioanalytical Chemistry, 2010Co-Authors: Ha Minh Hiep, Masato Saito, Yoshikazu Nakamura, Eiichi TamiyaAbstract:Developments of optical protein sensors with nanostructure based on the noble metals have currently received great attention for their high efficiency and simultaneous analysis of various important biomolecules from proteomics to genetics. In this study, we exploited the absorbance spectra of gold-capped nanoparticles substrate for label-free detections of Antigen-Antibody Reactions using a specific thiolated RNA aptamer. These synthesized RNA aptamers have been optimized to bind to the Fc portion of the human IgG1 subclass, due to their ability to orient antibodies direction on the gold surface. After attaching the anti-fibrinogen antibodies on the surface via these linkers, our thiolated RNA aptamer-based nanostructured sensors were easily applicable to specific detections of fibrinogen with a limit of detection of 0.1 ng/mL. These nanostructured sensor-based models will open a way to display numerous immunosensors as well as to develop other functionally similar sensors which could then be expanded into multi-arrays assay systems.
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gold nanoparticle based immunochromatography using a resin modified micropipette tip for rapid and simple detection of human chorionic gonadotropin hormone and prostate specific antigen
Science and Technology of Advanced Materials, 2006Co-Authors: Teruko Yuhi, Naoki Nagatani, Tatsuro Endo, Kagan Kerman, Masayuki Takata, Hiroyuki Konaka, Mikio Namiki, Yuzuru Takamura, Eiichi TamiyaAbstract:A novel bioanalysis system based on immunochromatography was developed in connection with a nitrocellulose resin-modified micropipette tip, namely as ZipTip®. The sandwich-type immunoassay was applied to our bioananalysis system. The first antibodies that were aspirated by the micropipette were immobilized on the immunochromatographic resin at the edge of micropipette tip. The blocking solution was also aspirated in the same fashion. The measurement operation was performed by aspirating the sample solution, and then the gold colloidal nanoparticles (Au naps) conjugated secondary antibody solution. Since this bioanalysis system utilizes a micropipette, it is possible to increase the sample volume, which would enable the detection of antigen at low concentrations. In addition, the washing procedure can also be performed easily to reduce the background level. After the Antigen-Antibody reaction, the color intensity of Au naps could be observed by the naked eye. For analytical evaluation, the color intensity was captured by a scanner, and processed by analysis software. We have achieved the detection of human chorionic gonadotropin hormone (hCG) and total prostate-specific antigen (TPSA), which are well-known as fundamental indicators of pregnancy and cancer. The limit of detection (LOD) for hCG was 8 ng/ml (0.8 ng/tip), which is comparable to that of other conventional systems based on immunochromatography. Moreover, the LOD for TPSA was improved over the existing systems with the application of different sample volumes, such as 5 ng/ml (1 ng/tip) in 200 μl sample volume, and 2 ng/ml (0.6 ng/tip) in 300 μl sample volume. Since our bioanalysis system requires a small amount of immobilized antigen, it would be greatly useful in basic research for screening the antigen–antibody Reactions. Besides, our bioanalysis system can be applied to on-field screening, since its operation is simple, and the visual results can be obtained rapidly.
Košťálková Helena - One of the best experts on this subject based on the ideXlab platform.
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The other human red blood groups systems.
2012Co-Authors: Košťálková HelenaAbstract:Immunohematology studies Antigen-Antibody Reactions and different forms of antigens and antibodies which cause the immunologic reaction of the organism. One of the hazards of blood transfusion is the immunization of individuals. The reaction between antigens and antibodies leads to the binding of the antibodies on the red blood cells membranes and premature degradation. Development of the antibodies affects about 0.1 - 3 % of the human population. Currently 270 blood group systems are known. The National Reference Laboratory for Imunohematology determines the specificity of antibodies against the blood group systems Diego, Yt, Xg, Scianna, Dombrock, Colton, Landsteiner-Wiener, Gerbich, Cromer, Knops, Indian, Ok, John Milton Hagen, HFA and LFA. For the detection of antibodies against the mentioned blood group systems uses the laboratory proper assays and Scarf - an archive of serum with antibodies and red blood cells containing the special antigens. Over the time period since 1st January 2007 till 31st December 2011 102 antibodies against the named blood group systems were detected. Some of these antibodies are clinically significant and subsequent hemoteraphie is very complicated. The most detected antibody was anti-Wr(a), an antibody against the low frequent antigen Wr(a) Diego system
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The other human red blood groups systems.
Univerzita Karlova Farmaceutická fakulta v Hradci Králové, 2012Co-Authors: Košťálková HelenaAbstract:SOUHRN Imunohematologie je oborem studujícím příčiny, průběh a následky obranných reakcí organismu vyvolaných reakcí krevních antigenů a odpovídajících protilátek. Jedním z rizik podání krevní transfuze či těhotenství je imunizace jedince. Reakce mezi antigeny a protilátkami vede k navázání protilátek na erytrocyty a k předčasnému rozpadu erytrocytu. Formování protilátek postihuje 0,1 - 3 % populace. V současnosti je známo kolem 270 skupinových antigenů. Specificita protilátek proti skupinovým systémům Diego, Yt, Xg, Scianna, Dombrock, Colton, Landsteiner-Wiener, Gerbich, Cromer, Knops, Indian, Ok, John Milton Hagen, HFA a LFA je určována pouze v Národní referenční laboratoři pro imunohematologii ÚHKT. Vysoce specializovaná laboratoř používá vhodné metody a tzv. Scarf antiséra a erytrocyty pro identifikaci protilátek proti jmenovaným systémům. V období 1. 1. 2007 - 31. 12. 2011 bylo v NRL pro imunohematologii určeno 102 protilátek proti těmto systémům. Některé z těchto protilátek patří mezi klinicky významné a následná hemoterapie je velice komplikovaná. Nejčastěji byla detekována protilátka proti antigenu s nízkou frekvencí Wr(a) systému Diego.Immunohematology studies Antigen-Antibody Reactions and different forms of antigens and antibodies which cause the immunologic reaction of the organism. One of the hazards of blood transfusion is the immunization of individuals. The reaction between antigens and antibodies leads to the binding of the antibodies on the red blood cells membranes and premature degradation. Development of the antibodies affects about 0.1 - 3 % of the human population. Currently 270 blood group systems are known. The National Reference Laboratory for Imunohematology determines the specificity of antibodies against the blood group systems Diego, Yt, Xg, Scianna, Dombrock, Colton, Landsteiner-Wiener, Gerbich, Cromer, Knops, Indian, Ok, John Milton Hagen, HFA and LFA. For the detection of antibodies against the mentioned blood group systems uses the laboratory proper assays and Scarf - an archive of serum with antibodies and red blood cells containing the special antigens. Over the time period since 1st January 2007 till 31st December 2011 102 antibodies against the named blood group systems were detected. Some of these antibodies are clinically significant and subsequent hemoteraphie is very complicated. The most detected antibody was anti-Wr(a), an antibody against the low frequent antigen Wr(a) Diego system.Department of Biological and Medical SciencesKatedra biologických a lékařských vědFaculty of Pharmacy in Hradec KrálovéFarmaceutická fakulta v Hradci Králov
Jing Jin - One of the best experts on this subject based on the ideXlab platform.
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prozone effect in the diagnosis of lupus anticoagulant for the lupus anticoagulant hypoprothrombinemia syndrome
American Journal of Clinical Pathology, 2016Co-Authors: Jing Jin, James L. ZehnderAbstract:Objectives: The main clinical sequela of a lupus anticoagulant is increased thrombosis risk. However, bleeding due to lupus anticoagulant-hypoprothrombinemia syndrome is a rare but well-described manifestation of antiphospholipid syndrome. The association of acute acquired hypoprothrombinemia is caused by a lupus anticoagulant’s specificity to prothrombin, which results in clearance of prothrombin and bleeding due to hypoprothrombinemia (usually <10% of normal). Severe life-threatening bleeding is most frequently reported in children with systemic lupus erythematosus or in healthy children after viral infection. In such cases, steroid therapy is usually effective in controlling the bleeding problems and improving prothrombin levels. Methods: We report one pediatric patient with a lupus anticoagulant who had acute hemorrhagic diathesis. Results: The diagnosis in this case was complicated by the presence of a prozone effect in lupus anticoagulant testing. The prozone effect (also known as hook effect) refers to situations where very high concentrations of antibody mask detection, typically in Antigen-Antibody Reactions, which depend on visualization of agglutination. Decreasing the antibody/antigen ratio results in detectable Antigen-Antibody complexes. Conclusions: We report for the first time a variation on this theme in a patient with a lupus anticoagulant-type antiphospholipid antibody and hypoprothrombinemia, which corrected with immunosuppression and restoration of normal prothrombin levels.
Catherine Satzke - One of the best experts on this subject based on the ideXlab platform.
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Video Article Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction
2016Co-Authors: Maha Habib, Barbara D Porter, Catherine SatzkeAbstract:e51208, doi:10.3791/51208 (2014). There are over 90 different capsular serotypes of Streptococcus pneumoniae (the pneumococcus). As well as being a tool for understanding pneumococcal epidemiology, capsular serotyping can provide useful information for vaccine efficacy and impact studies. The Quellung reaction is the gold standard method for pneumococcal capsular serotyping. The method involves testing a pneumococcal cell suspension with pooled and specific antisera directed against the capsular polysaccharide. The Antigen-Antibody Reactions are observed microscopically. The protocol has three main steps: 1) preparation of a bacterial cell suspension, 2) mixing of cells and antisera on a glass slide, and 3) reading the Quellung reaction using a microscope. The Quellung reaction is reasonably simple to perform and can be applied wherever a suitable microscope and antisera are available. Video Link The video component of this article can be found a
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capsular serotyping of streptococcus pneumoniae using the quellung reaction
Journal of Visualized Experiments, 2014Co-Authors: Maha Habib, Barbara D Porter, Catherine SatzkeAbstract:There are over 90 different capsular serotypes of Streptococcus pneumoniae (the pneumococcus). As well as being a tool for understanding pneumococcal epidemiology, capsular serotyping can provide useful information for vaccine efficacy and impact studies. The Quellung reaction is the gold standard method for pneumococcal capsular serotyping. The method involves testing a pneumococcal cell suspension with pooled and specific antisera directed against the capsular polysaccharide. The Antigen-Antibody Reactions are observed microscopically. The protocol has three main steps: 1) preparation of a bacterial cell suspension, 2) mixing of cells and antisera on a glass slide, and 3) reading the Quellung reaction using a microscope. The Quellung reaction is reasonably simple to perform and can be applied wherever a suitable microscope and antisera are available.