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Sample records for direct competitive enzyme-linked

  1. Development of a direct competitive enzyme-linked immunosorbent assay for parathion residue in food samples.

    Science.gov (United States)

    Gui, Wen-Jun; Liu, Yi-Hua; Wang, Chun-Mei; Liang, Xiao; Zhu, Guo-Nian

    2009-10-01

    A heterologous direct competitive enzyme-linked immunosorbent assay (ELISA) for parathion residue determination is described based on a monoclonal antibody and a new competitor. The effects of several physicochemical factors, such as methanol concentration, ionic strength, pH value, and sample matrix, on the performance of the ELISA were optimized for the sake of obtaining a satisfactory assay sensitivity. Results showed that when the assay medium was in the optimized condition (phosphate buffer solution [PBS] containing 10% [v/v] methanol and 0.2 mol/L NaCl at a pH value of 5.0), the sensitivity (estimated as the IC(50) value) and the limit of detection (LOD, estimated as the IC(10) value) were 1.19 and 0.08 ng/ml, respectively. The precision investigation indicated that the intraassay precision values all were below 10% and that the interassay precision values ranged from 4.89 to 19.12%. In addition, the developed ELISA showed a good linear correlation (r(2)=0.9962) to gas chromatography within the analyte's concentration range of 0.1 to 16 ng/ml. When applied to the fortified samples (parathion adding level: 5-15 microg/kg), the developed ELISA presented mean recoveries of 127.46, 122.52, 91.92, 124.01, 129.72, 99.37, and 87.17% for tomato, cucumber, banana, apple, orange, pear, and sugarcane, respectively. Results indicated that the established ELISA is a potential tool for parathion residue determination.

  2. Comparisons of competitive enzyme-linked immunosorbent assay ...

    African Journals Online (AJOL)

    The aim of this study was to comprise competitive enzyme-linked immunosorbent assay (C-ELISA) with one step RT-PCR test for the detection of BTV in sheep. A total of 770 blood samples were obtained from sheep (265 serum positive samples and 505 serum negative samples in C-ELISA). According to our data, out of ...

  3. A competitive enzyme linked immunosorbent assay for the ...

    African Journals Online (AJOL)

    A competitive enzyme linked immunosorbent assay for the determination of diminazene residues in animal tissues. ... After six washes with buffer, enzyme activity was determined by adding tetramethyl-benzidine and hydrogen peroxide as substrate. The assay detection limits for diminazene were 2.4 ng/g in muscle, 2.5 ...

  4. Enzyme-linked, aptamer-based, competitive biolayer interferometry biosensor for palytoxin.

    Science.gov (United States)

    Gao, Shunxiang; Zheng, Xin; Hu, Bo; Sun, Mingjuan; Wu, Jihong; Jiao, Binghua; Wang, Lianghua

    2017-03-15

    In this study, we coupled biolayer interferometry (BLI) with competitive binding assay through an enzyme-linked aptamer and developed a real-time, ultra-sensitive, rapid quantitative method for detection of the marine biotoxin palytoxin. Horseradish peroxidase-labeled aptamers were used as biorecognition receptors to competitively bind with palytoxin, which was immobilized on the biosensor surface. The palytoxin: horseradish peroxidase-aptamer complex was then submerged in a 3,3'-diaminobenzidine solution, which resulted in formation of a precipitated polymeric product directly on the biosensor surface and a large change in the optical thickness of the biosensor layer. This change could obviously shift the interference pattern and generate a response profile on the BLI biosensor. The biosensor showed a broad linear range for palytoxin (200-700pg/mL) with a low detection limit (0.04pg/mL). Moreover, the biosensor was applied to the detection of palytoxin in spiked extracts and showed a high degree of selectivity for palytoxin, good reproducibility, and stability. This enzyme-linked, aptamer-based, competitive BLI biosensor offers a promising method for rapid and sensitive detection of palytoxin and other analytes. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. The Use of Competitive Enzyme Linked Immuno-Sorbent Assay in ...

    African Journals Online (AJOL)

    A total of 500 lung tissues and sera samples of cattle from CBPP endemic areas was used in this study to determine the effectiveness of combining abattoir survey with competitive Enzyme Linked Immunosorbent Assay (cELISA) as an alternative to Complement Fixation Test (CFT) in providing a better and more reliable ...

  6. Determination of xanthine oxidase in human serum by a competitive enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    Battelli, M G; Abbondanza, A; Musiani, S; Buonamici, L; Strocchi, P; Tazzari, P L; Gramantieri, L; Stirpe, F

    1999-03-01

    Xanthine oxidase was purified from human milk and used to immunise rabbits. A competitive immunoenzymatic assay with purified enzyme and rabbit antiserum was optimised to measure xanthine oxidase in human serum, the lowest detectable amount being 0.03 pmol of enzymatic protein. Thus, the test (i) is sensitive enough to determine xanthine oxidase in human serum, being more sensitive than the spectrophotometric method, (ii) it is more convenient for clinical laboratories than other sensitive tests and (iii) it has the advantage over the enzyme activity-based assays of also detecting inactive enzyme molecules. A competitive enzyme-linked immunosorbent assay (ELISA) was used to measure the serum xanthine oxidase level in healthy donors and in patients with liver diseases, and it was found that any concentration below 1 mg/L is in the normal range.

  7. Biotin-Streptavidin Competition Mediates Sensitive Detection of Biomolecules in Enzyme Linked Immunosorbent Assay.

    Science.gov (United States)

    Lakshmipriya, Thangavel; Gopinath, Subash C B; Tang, Thean-Hock

    2016-01-01

    Enzyme Linked Immunosorbent Assay (ELISA) is the gold standard assay for detecting and identifying biomolecules using antibodies as the probe. Improving ELISA is crucial for detecting disease-causing agents and facilitating diagnosis at the early stages of disease. Biotinylated antibody and streptavidin-conjugated horse radish peroxide (streptavidin-HRP) often are used with ELISA to enhance the detection of various kinds of targets. In the present study, we used a competition-based strategy in which we pre-mixed free biotin with streptavidin-HRP to generate high-performance system, as free biotin occupies some of the biotin binding sites on streptavidin, thereby providing more chances for streptavidin-HRP to bind with biotinylated antibody. ESAT-6, which is a protein secreted early during tuberculosis infection, was used as the model target. We found that 8 fM of free biotin mixed with streptavidin-HRP anchored the higher detection level of ESAT-6 by four-fold compared with detection without free biotin (only streptavidin-HRP), and the limit of detection of the new method was 250 pM. These results suggest that biotin-streptavidin competition can be used to improve the diagnosis of analytes in other types of sensors.

  8. Methodology for determination of plasma cortisol in fish using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)

    DEFF Research Database (Denmark)

    Velasco-Santamaría, Yohana M.; Cruz-Casallas, Pablo E.

    2007-01-01

    Objective. To determine plasma cortisol procedure in fish using competitive enzymelinked immunosorbent assay (ELISA). Materials and methods. Two plasma samples of juveniles rainbow trout Oncorhynchus mykiss were analized by using ELISA human kit for cortisol assay. For standard curve calibration ...

  9. Direct microculture enzyme-linked immunosorbent assay for studying neural cells: oligodendrocytes.

    Science.gov (United States)

    Gard, A L; Warrington, A E; Pfeiffer, S E

    1988-05-01

    Oligodendrocyte development has been studied in a standardized primary microculture system initiated from day 20-21 fetal rat brain using a solid-phase enzyme-linked immunosorbent assay (ELISA) carried out directly on fixed cells (direct microculture ELISA). A highly reproducible dissociation procedure is described that allows careful control of the number of cells seeded per culture. At a seeding density of 1 x 10(5) cells/culture, up to 250 oligodendrocyte-generating microcultures consisting of 10-12% oligodendrocytes can be prepared from a single fetal rat brain, thereby permitting the simultaneous assay of multiple developmental parameters in sibling cultures. The validity of this method for quantifying myelinogenesis was established by comparing the results obtained by direct microculture ELISA with immunocytochemical counting of cells in parallel cultures. As few as 200 oligodendrocytes could be detected using a biotinylated anti-Ig and an avidin-urease conjugate detection system; CNP immunoreactivity measured by ELISA was linearly proportional to the number of immunolabeled cells between 6 and 34 days in culture; the developmental time courses of 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) and myelin basic protein (MBP) expression determined by the two methods were very similar. Finally, cell suspensions were seeded at increasing dilution to determine the number of cells required to generate cultures that tested positive for oligodendrocytes by ELISA. As few as 9,000 cells were sufficient, predicting a minimum of 8,000 oligoprogenitors per 20-21 day fetal rat brain. The application of direct microculture ELISA for studying oligodendrocyte population size and myelinogenesis is discussed.

  10. Field trial of a brucellosis competitive enzyme linked immunoabsorbent assay (ELISA)

    International Nuclear Information System (INIS)

    Samartino, L.E.; Gregoret, R.J.; Sigal, G.

    1998-01-01

    The purpose of this study was to evaluate the performance of a competitive ELISA system for the diagnosis of bovine brucellosis in comparison to conventional aerological tests routinely used in Argentina. A total of 2.500 serum samples, comprising Brucella-free herds, vaccinated cattle and naturally infected animals, was tested by the following tests: buffered plate agglutination, Rose Bengal, 2-mercaptoethanol, complement fixation, and indirect and competitive ELISAs. Specificity and relative sensitivity at each test were determined. The competitive ELISA was considered suitable for detection of vaccinated animals and had higher specificity than the other tests. The results point to the potential use of the test as a complementary assay in the brucellosis control programme in Argentina. (author)

  11. Investigation of caprine arthritis-encephalitis virus in Sudan using competitive enzyme-linked immunosorbent assay

    Directory of Open Access Journals (Sweden)

    Rajaa H. Halfawi

    2013-06-01

    Full Text Available Aim: This seroprevalence study was carried out to detect anti Caprine Arthritis-Encephalitis Virus (CAEV antibodies in goat sera in five States in the Sudan during 2009 and 2010. Materials and Methods: In this study, four hundred and thirty two sera samples collected from five States in the Sudan were screened for anti-CAE virus antibodies using a commercial competitive ELISA (cELISA kit. Results: Out of 432 samples, 25 (5.8% tested positive using ELISA. The highest prevalence was recorded in El-gazira State (19%, whereas in Kassala State the prevalence was 10.7%, Khartoum State (0.92% and no positive antibodies were found in Northern and River Nile. Conclusion: The information obtained in this study showed that the disease spread to other states in the Sudan beside Khartoum state. Therefore, further epizootiological investigation on CAEV and Maedi Visna Virus at the country level is important to monitor its spread and determine its economic impact in the Sudan, while better control on imported animals for genetic improvement must be instituted. [Vet World 2013; 6(8.000: 558-562

  12. Evaluation of a competitive enzyme-linked immunosorbent assay for measurements of soluble HLA-G protein

    DEFF Research Database (Denmark)

    Rasmussen, Mette; Dahl, Mette; Buus, Søren

    2014-01-01

    The human leukocyte antigen (HLA) class Ib molecule, HLA-G, has gained increased attention because of its assumed important role in immune regulation. The HLA-G protein exists in several soluble isoforms. Most important are the actively secreted HLA-G5 full-length isoform generated by alternative...... splicing retaining intron 4 with a premature stop codon, and the cleavage of full-length membrane-bound HLA-G1 from the cell surface, so-called soluble HLA-G1 (sHLA-G1). A specific and sensitive immunoassay for measurements of soluble HLA-G is mandatory for conceivable routine testing and research projects....... We report a novel method, a competitive immunoassay, for measuring HLA-G5/sHLA-G1 in biological fluids. The sHLA-G immunoassay is based upon a competitive enzyme-linked immunosorbent assay (ELISA) principle. It includes a recombinant sHLA-G1 protein in complex with β2-microglobulin and a peptide...

  13. Serosurveillance for Francisella tularensis among wild animals in Japan using a newly developed competitive enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Sharma, Neekun; Hotta, Akitoyo; Yamamoto, Yoshie; Uda, Akihiko; Fujita, Osamu; Mizoguchi, Toshio; Shindo, Junji; Park, Chun-Ho; Kudo, Noboru; Hatai, Hitoshi; Oyamada, Toshifumi; Yamada, Akio; Morikawa, Shigeru; Tanabayashi, Kiyoshi

    2014-04-01

    Tularemia, a highly infectious zoonotic disease caused by Francisella tularensis, occurs sporadically in Japan. However, little is known about the prevalence of the disease in wild animals. A total of 632 samples obtained from 150 Japanese black bears, 142 Japanese hares, 120 small rodents, 97 rats, 53 raptors, 26 Japanese monkeys, 21 Japanese raccoon dogs, 20 masked palm civets, and three Japanese red foxes between 2002 and 2010 were investigated for the presence of antibodies to F. tularensis by competitive enzyme-linked immunosorbent assay (cELISA) and the commonly used microagglutination (MA) test. Seropositive cELISA and MA results were obtained in 23 and 18 Japanese black bears, three and two Japanese raccoon dogs, and two and one small rodents, respectively. All MA-positive samples (n=21) were also positive by cELISA. Six of seven samples that were only positive by cELISA were confirmed to be antibody-positive by western blot analysis. These findings suggest that cELISA is a highly sensitive and useful test for serosurveillance of tularemia among various species of wild animals. Because this is the first study to detect F. tularensis-seropositive Japanese raccoon dogs, these could join Japanese black bears as sentinel animals for tularemia in the wild in Japan. Further continuous serosurveillance for F. tularensis in various species of wild animals using appropriate methods such as cELISA is important to assess the risks of human exposure and to improve our understanding of the ecology of F. tularensis in the wild.

  14. Identification of phlebotomine sandfly bloodmeals from Baringo District, Kenya, by direct enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    Ngumbi, P M; Lawyer, P G; Johnson, R N; Kiilu, G; Asiago, C

    1992-10-01

    Direct enzyme-linked immunosorbent assay (ELISA) was used to identify the sources of bloodmeals in phlebotomine sandflies from Baringo District, Rift Valley Province, Kenya. Some bloodmeals had been stored for over 4 years before being analysed. Among 356 sandflies identified, 62.9% were Phlebotomus martini, 14.8% Sergentomyia antennatus, 10% S.schwetzi, 6% S.clydei, 1.9% S.adleri, 1.6% P.duboscqi, 1.4% S.africanus and 0.8% S.bedfordi. Out of 224 P.martini bloodmeals, host source was identified for 69. The order of host preference for P.martini was: goat 28.5%, rabbit 22.7%, human 8.9% and others 8.9%. Evidence of mixed feeding was shown by four species comprising sixteen specimens, twelve of which were P.martini. The most effective methods for trapping bloodfed P. martini were sticky paper traps in termite hills, followed by light-traps. Of the 224 P.martini trapped, 58.9% were collected with traps in termite hills, and 22.7% with light traps. Roles of the three most popular hosts for P.martini should be investigated to ascertain whether they act as reservoirs in the transmission of Leishmania donovani causing visceral leishmaniasis in Kenya.

  15. Detection of Ganoderic Acid A in Ganoderma lingzhi by an Indirect Competitive Enzyme-Linked Immunosorbent Assay.

    Science.gov (United States)

    Sakamoto, Seiichi; Kohno, Toshitaka; Shimizu, Kuniyoshi; Tanaka, Hiroyuki; Morimoto, Satoshi

    2016-05-01

    Ganoderma is a genus of medicinal mushroom traditionally used for treating various diseases. Ganoderic acid A is one of the major bioactive Ganoderma triterpenoids isolated from Ganoderma species. Herein, we produced a highly specific monoclonal antibody against ganoderic acid A (MAb 12 A) and developed an indirect competitive ELISA for the highly sensitive detection of ganoderic acid A in Ganoderma lingzhi, with a limit of detection of 6.10 ng/mL. Several validation analyses support the accuracy and reliability of the developed indirect competitive ELISA for use in the quality control of Ganoderma based on ganoderic acid A content. Furthermore, quantitative analysis of ganoderic acid A in G. lingzhi revealed that the pileus exhibits the highest ganoderic acid A content compared with the stipe and spore of the fruiting body; the best extraction efficiency was found when 50 % ethanol was used, which suggests the use of a strong liquor to completely harness the potential of Ganoderma triterpenoids in daily life. Georg Thieme Verlag KG Stuttgart · New York.

  16. Development and validation of an indirect competitive enzyme linked-immunosorbent assay for the determination of potentially allergenic sesame (Sesamum indicum) in food.

    Science.gov (United States)

    Husain, Fatima Tazeen; Bretbacher, Ines Elisabeth; Nemes, Albert; Cichna-Markl, Margit

    2010-02-10

    This study was designed to develop an indirect competitive enzyme linked-immunosorbent assay (ELISA) to detect traces of sesame in food. Antibodies against sesame were prepared by immunizing a hen with a protein extract of white, peeled sesame. The ELISA did not show any cross-reactivity with 12 of 13 food ingredients tested, only for chocolate was a low cross-reactivity of 0.7% observed. To eliminate matrix effects, sesame protein standard solutions were prepared by diluting the sesame extract with blank food matrix (1:20 diluted with PBS). Recovery of sesame protein in food samples (crisp toasts, snacks, and rolls) spiked with different sesame protein concentrations ranged from 85% to 120%, with the exception of multigrain crisp toast, resulting in too high recoveries (117%-160%) and whole grain bread, yielding too low recoveries (70%-85%). In crisp bread, cracker, cereals, and snacks the limit of detection (LOD) was found to be 5 microg of sesame protein/g of food, in fresh breads and rolls, the LOD was 11 microg of sesame protein/g of food.

  17. Development of an indirect competitive enzyme-linked immunosorbent assay applied to the Botrytis cinerea quantification in tissues of postharvest fruits

    Science.gov (United States)

    2011-01-01

    Background Botrytis cinerea is a phytopathogenic fungus responsible for the disease known as gray mold, which causes substantial losses of fruits at postharvest. This fungus is present often as latent infection and an apparently healthy fruit can deteriorate suddenly due to the development of this infection. For this reason, rapid and sensitive methods are necessary for its detection and quantification. This article describes the development of an indirect competitive enzyme-linked immunosorbent assay (ELISA) for quantification of B. cinerea in apple (Red Delicious), table grape (pink Moscatel), and pear (William's) tissues. Results The method was based in the competition for the binding site of monoclonal antibodies between B. cinerea antigens present in fruit tissues and B. cinerea purified antigens immobilized by a crosslinking agent onto the surface of the microtiter plates. The method was validated considering parameters such as selectivity, linearity, precision, accuracy and sensibility. The calculated detection limit was 0.97 μg mL-1 B. cinerea antigens. The immobilized antigen was perfectly stable for at least 4 months assuring the reproducibility of the assay. The fungus was detected and quantified in any of the fruits tested when the rot was not visible yet. Results were compared with a DNA quantification method and these studies showed good correlation. Conclusions The developed method allowed detects the presence of B. cinerea in asymptomatic fruits and provides the advantages of low cost, easy operation, and short analysis time determination for its possible application in the phytosanitary programs of the fruit industry worldwide. PMID:21970317

  18. Development and validation of an indirect competitive enzyme-linked immunosorbent assay for the screening of tylosin and tilmicosin in muscle, liver, milk, honey and eggs.

    Science.gov (United States)

    Peng, Dapeng; Ye, Shengqiang; Wang, Yulian; Chen, Dongmei; Tao, Yanfei; Huang, Lingli; Liu, Zhenli; Dai, Menghong; Wang, Xiaoqing; Yuan, Zonghui

    2012-01-11

    Incorrect use of tylosin and tilmicosin could result in allergy and select resistance. To monitor the illegal use of these antibiotics in animals, a monoclonal-based indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) has been established. Several haptens were synthesized and conjugated to carrier protein. Female Balb/c mice were inoculated with the four different conjugates to produce monoclonal antibodies according to the schemes of immunization. Aftercell fusion and culture several times, nine hybridoma cell lines were isolated. Only one, 3C4 that has isotype IgG2a, was selected for detailed study. The cross-reactivity of the monoclonal antibody 3C4 to tylosin and tilmicosin was 100% and 51% respectively. The standard curves based on the tylosin and tilmicosin matrix calibration ranged from 2.5 to 40 μg L(-1), with an IC(50) value of 6.1 μg L(-1) and 12.1 μg L(-1), respectively. The limits of detection of the ic-ELISA ranged from 5.1 μg kg(-1) to 13.8 μg kg(-1) in edible animal tissues. The recoveries were 74.1% to 120.7% with less than 18.6% of the coefficient of variation when tylosin and tilmicosin were spiked in various biological matrices with the concentrations of 25.0-200.0 μg kg(-1). Good correlations between the results of the ic-ELISA and high performance liquid chromatography were observed in the incurred tissues. These results suggest that the ic-ELISA is a sensitive, accurate and low-cost method that would be a useful tool for the screening of the residues of tylosin and tilmicosin in muscle, liver, milk, honey and eggs.

  19. Preparation and characterization of domoic acid-protein conjugates using small amount of toxin in a reversed micellar medium: application in a competitive enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Branaa, P; Naar, J; Chinain, M; Pauillac, S

    1999-01-01

    With the aim of producing novel antibodies to domoic acid (DA), an original, rapid, and simple procedure for preparing minute amount of hapten-protein conjugates was developed. The amide-bond-generating mixed anhydride method of Erlanger was performed using 0.32-0.64 micromol of DA in a reversed micellar medium allowing strong carrier haptenization as determined by spectrophotometric measurement. Bovine serum albumin (BSA) and ovalbumin (OVA) conjugates were, respectively, used for immunization of BALB/c mice and antibody screening by enzyme-linked immunosorbent assay (ELISA). Specific polyclonal antibodies were produced upon multiple injections of (DA)(17)-BSA conjugate administered by three different routes: (i) intraperitoneal (i.p.), (ii) intraperitoneal + subcutaneous (i.p. + s.c.), (iii) footpad (f.p.). The i.p. route induced antisera of higher titer (1:350000) than did the other protocols (approximately 1:72900) and was selected throughout further experiments. Using a competitive ELISA format with a peroxidase immunoconjugate and a chromogenic substrate, no significant cross-reactivity was observed with glutamic acid, aspartic acid and kainic acid (KA), a structural analogue of DA. The sensitivity of this assay could be enhanced by 1 order of magnitude by using a beta-galactosidase immunoconjugate with a fluorogenic substrate while preserving DA specificity. The calculated dissociation constant (K(D)) for the interaction of the antibodies with free DA was 5 x 10(-)(7) M (chromogenic assay) and 5 x 10(-)(8) M (fluorogenic assay). Using the optimized assay the limit of detection (LOD) and the limit of quantitation (LOQ) in the ELISA buffer were 1.4 and 3 ng/mL, respectively. Moreover this assay was found applicable for measuring DA levels in spiked mussel extracts pre-cleaned through a solid-phase extraction column, as a very good correlation (r(2) = 0.96) was observed between the actual amounts of DA added and amounts detected by ELISA. Thus, accurate

  20. Comparative study of direct and indirect immunofluorescence and of bullous pemphigoid 180 and 230 enzyme-linked immunosorbent assays for diagnosis of bullous pemphigoid.

    Science.gov (United States)

    Sárdy, Miklós; Kostaki, Dimitra; Varga, Rita; Peris, Ketty; Ruzicka, Thomas

    2013-11-01

    Direct immunofluorescence (DIF), indirect immunofluorescence (IIF), and enzyme-linked immunosorbent assay (ELISA) are used for the laboratory diagnosis of bullous pemphigoid (BP). The diagnostic value of DIF and IIF on rabbit and monkey esophagus or human salt-split skin and commercial ELISAs was assessed. This was a single-center retrospective study where 313 patients with BP were compared with 488 control subjects. DIF was the most sensitive test (90.8%) whereas sensitivities for IIF on rabbit esophagus, IIF on monkey esophagus, IIF on salt-split skin, BP180 ELISA, and BP230 ELISA were 76.0%, 73.2%, 73.3%, 72.0%, and 59.0%, respectively. The sensitivity of the serologic tests was 88.8% altogether. The specificities for DIF, IIF on rabbit esophagus, IIF on monkey esophagus, IIF on salt-split skin, BP180 ELISA, and BP230 ELISA were 98%, 96.5%, 97.1%, 100%, 94.1%, and 99.2%, respectively. The retrospective nature of study was a limitation. Correlation of diagnostic data with clinical manifestations or disease course was not possible. In suspected BP, both serologic tests and DIF have to be performed because of a sensitivity issue. Although the ELISAs had a relatively low sensitivity, the serologic tests altogether almost reached the level of sensitivity of DIF. The specificities of all assays were excellent. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  1. The usefulness of direct agglutination test, enzyme-linked immunosorbent assay and polymerase chain reaction for the detection of Toxoplasma gondii in wild animals.

    Science.gov (United States)

    Kornacka, Aleksandra; Cybulska, Aleksandra; Bień, Justyna; Goździk, Katarzyna; Moskwa, Bożena

    2016-09-15

    The aim of the study was to compare the usefulness of two antibody-based methods, the direct agglutination test (DAT) and enzyme linked immuosorbent assay (ELISA), with that of the polymerase chain reaction (PCR) for detecting anti-Toxoplasma gondii in samples derived from naturally-infected wild animals. Antibodies against T. gondii were detected in meat juice samples collected from 129 free- living carnivores and omnivores. T. gondii seroprevalence was confirmed in 73,6% of examined samples when DAT and ELISA were used separately, but in only 88,4% samples when both immunological tests were used in parallel. PCR results confirmed the presence of DNA of the parasite in 24 of all the 129 samples. Sixteen samples were classified as positive when all three tests were used. A moderate degree of agreement was found between DAT and ELISA (κ=0.55). However, no agreement was found between the molecular and serological tests: κ=-1.75 for DAT versus PCR; κ=-1.67 ELISA versus PCR. By using both serological tests, antibodies against T. gondii were found in 77.5% of red foxes, 12.5% of badgers, 40% of martens and 8.3% of raccoon dogs. Antibodies against the parasite were detected also in one mink, but not in the sample derived from a polecat. T.gondii DNA was found in the brain tissue of 20 red foxes, three badgers and one raccoon dog. Our studies confirm that ELISA and DAT are suitable and reliable techniques for T. gondii antibody detection in meat juice from wild animals when serum samples are unavailable. Positive results obtained by immunological tests do not always reflect that the host was infected by T. gondii. They indicate only a contact with parasite. PCR should be used to confirm te presence of DNA from T. gondii. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Chicken single-chain antibody fused to alkaline phosphatase detects Aspergillus pathogens and their presence in natural samples by direct sandwich enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Xue, Sheng; Li, He-Ping; Zhang, Jing-Bo; Liu, Jin-Long; Hu, Zu-Quan; Gong, An-Dong; Huang, Tao; Liao, Yu-Cai

    2013-11-19

    A sensitive and specific analytical method to detect ubiquitous aflatoxigenic Aspergillus pathogens is essential for monitoring and controlling aflatoxins. Four highly reactive chicken single-chain variable fragments (scFvs) against soluble cell wall proteins (SCWPs) from Aspergillus flavus were isolated by phage display. The scFv antibody AfSA4 displayed the highest activity toward both A. flavus and A. parasiticus and specifically recognized a surface target of their cell walls as revealed by immunofluorescence localization. Molecular modeling revealed a unique compact motif on the antibody surface mainly involving L-CDR2 and H-CDR3. As measured by surface plasmon resonance, AfSA4 fused to alkaline phosphatase had a higher binding capability and 6-fold higher affinity compared with AfSA4 alone. Immunoblot analyses showed that the fusion had good binding capacity to SCWP components from the two fungal species. Direct sandwich enzyme-linked immunosorbent assays with mouse antiaspergillus monoclonal antibody mAb2A8 generated in parallel as a capture antibody revealed that the detection limit of the two fungi was as low as 10(-3) μg/mL, 1000-fold more sensitive than that reported previously (1 μg/mL). The fusion protein was able to detect fungal concentrations below 1 μg/g of maize and peanut grains in both artificially and naturally contaminated samples, with at least 10-fold more sensitivity than that reported (10 μg/g) thus far. Thus, the fusion can be applied in rapid, simple, and specific diagnosis of Aspergillus contamination in field and stored food/feed commodities.

  3. Detection of Anaplasma antibodies in wildlife and domestic species in wildlife-livestock interface areas of Kenya by major surface protein 5 competitive inhibition enzyme-linked immunosorbent assay

    Directory of Open Access Journals (Sweden)

    J.J.N. Ngeranwa

    2008-09-01

    Full Text Available The seroprevalence of Anaplasma antibodies in wildlife (eland, blue wildebeest, kongoni, impala, Thomson's gazelle, Grant's gazelle, giraffe and plains zebra and domestic animal (cattle, sheep and goat populations was studied in wildlife / livestock interface areas of Kenya. Serum samples were analyzed by competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA, using a recombinant antigen (MSP-5 from Anaplasma marginale surface membrane. A monoclonal antibody, FC-16, was used as the primary antibody, while anti-mouse conjugated to horseradish peroxidase was used as the secondary antibody. The results indicate a high seroprevalence in both wildlife and livestock populations, in contrast to earlier reports from Kenya, which indicated a low seroprevalence. The differences are attributed to the accurate analytical method used (CI-ELISA, as compared with agglutination techniques, clinical signs and microscopy employed by the earlier workers.

  4. Validation according to OIE criteria of a monoclonal, recombinant p26-based, serologic competitive enzyme-linked immunosorbent assay as screening method in surveillance programs for the detection of Equine infectious anemia virus antibodies.

    Science.gov (United States)

    Nardini, Roberto; Autorino, Gian Luca; Ricci, Ida; Frontoso, Raffaele; Rosone, Francesca; Simula, Massimiliano; Scicluna, Maria Teresa

    2016-03-01

    The Italian National Reference Center for equine infectious anemia (CRAIE; Rome, Italy) developed and validated a monoclonal, recombinant p26-based competitive enzyme-linked immunosorbent assay (cELISA) for the detection of EIA virus antibodies employing the 2010 criteria of the World Organization for Animal Health (OIE). The following parameters were evaluated: cutoff values, repeatability, reproducibility, concordance, analytical sensitivity (Se), absolute analytical specificity (Sp), and diagnostic Se and Sp. Positive and negative predictive values were also defined in relation to the estimated prevalence. When the cELISA was used as a screening test for 96,468 samples in the Italian EIA surveillance program, 17% more EIA cases were detected than by the agar gel immunodiffusion test, and the apparent diagnostic Sp estimated from these samples was 99.8%, which was more than the diagnostic Sp (80.2%) estimated from validation. The high Se and Sp of the cELISA confirm its fit for purpose as a screening test. © 2015 The Author(s).

  5. Development of an enzyme-linked immunosorbent assay for toosendanin.

    Science.gov (United States)

    Zhang, Jing; Feng, Gang; Luo, Li; Yu, Xiang Yang; Ma, Zhi Qing; Feng, Jun Tao; Liu, Xian Jin; Zhang, Xing

    2008-08-01

    Enzyme-linked immunosorbent assays (ELISAs) were developed by using polyclonal antibody for toosendanin (TSN), a biopesticide from Melai toosendan Sieb. et Zucc. Their application in the determination of this analyte in spiked cabbage, tomato and apple samples was studied. The haptens, 28-hemisuccinyl-TSN (TSN-S) and 28-hemiglutaryl-TSN (TSN-G) were synthesized by using esterification. Immunogen and coating antigen were synthesized by using the mixed anhydride reaction and active ester protocol, respectively. Rabbits were immunized with TSN-G-BSA and TSN-S-BSA. Using the selected antibody and coating antigen, an indirect competitive ELISA for TSN was developed, which showed an IC(50) value of 1.023 microg mL(-1), with a detection limit of 0.009 microg mL(-1). A direct competitive ELISA using an enzyme tracer was also developed. The assay showed an IC(50) value of 0.840 microg mL(-1) with a detection limit of 0.014 microg mL(-1). Both assays displayed high cross-reactivity to a closely structurally related compound. Recoveries of TSN from both immunoassays of fortified samples ranged from 76.4% to 113.2% and 75.1% to 132.3%, respectively. Linear regression analysis showed good correlation between the TSN concentrations derived from ELISA and HPLC analyses, which suggested that the ELISA is a convenient supplementary analytical tool for monitoring TSN.

  6. Comparison of desmoglein 1 and 3 enzyme-linked immunosorbent assay and direct immunofluorescence for evaluation of immunological remission in pemphigus vulgaris.

    Science.gov (United States)

    Daneshpazhooh, M; Kamyab, K; Kalantari, M-S; Balighi, K; Naraghi, Z S; Shamohammadi, S; Mortazavizadeh, S M-A; Ramezani, A; Chams-Davatchi, C

    2014-01-01

    Drug withdrawal is the ultimate goal in the management of patients with pemphigus. Direct immunofluorescence (DIF) has long been considered the gold-standard test to predict immunological remission in pemphigus vulgaris (PV); however, there have been no comparisons between DIF and antidesmoglein (anti-Dsg) ELISA. To compare anti-Dsg ELISA with DIF in patients with PV for evaluation of immunological remission. The study enrolled 46 patients with PV who had absence of any lesion, and had a daily prednisolone dosage of ≤ 10 mg without adjuvant drug treatment in the preceding 6 months. Biopsy specimens were taken from patients and processed for DIF. Intercellular deposition of IgG and/or C3 was considered positive. Serum samples were also collected for anti-Dsg1 and anti-Dsg3 ELISA, and an ELISA index value of > 20.0 was considered positive. DIF and anti-Dsg ELISA were positive for 11 (23.9%) and 18 patients (39.1%), respectively. Anti-Dsg ELISA had a sensitivity of 100%, a specificity of 80%, a positive predictive value of 61.1% and a negative predictive value of 100%. The high sensitivity of anti-Dsg ELISA proves that this simple serological test is a good substitute for DIF for evaluation of immunological remission in PV. As none of the DIF-positive patients was anti-Dsg-negative, it is possible that during the course of immunological remission, results for DIF may become negative before the results for Dsg ELISA do so. © 2013 British Association of Dermatologists.

  7. Direct comparison of the histidine-rich protein-2 enzyme-linked immunosorbent assay (HRP-2 ELISA) and malaria SYBR green I fluorescence (MSF) drug sensitivity tests in Plasmodium falciparum reference clones and fresh ex vivo field isolates from Cambodia.

    Science.gov (United States)

    Chaorattanakawee, Suwanna; Tyner, Stuart D; Lon, Chanthap; Yingyuen, Kritsanai; Ruttvisutinunt, Wiriya; Sundrakes, Siratchana; Sai-gnam, Piyaporn; Johnson, Jacob D; Walsh, Douglas S; Saunders, David L; Lanteri, Charlotte A

    2013-07-12

    Performance of the histidine-rich protein-2 enzyme-linked immunosorbent assay (HRP-2 ELISA) and malaria SYBR Green I fluorescence (MSF) drug sensitivity tests were directly compared using Plasmodium falciparum reference strains and fresh ex vivo isolates from Cambodia against a panel of standard anti-malarials. The objective was to determine which of these two common assays is more appropriate for studying drug susceptibility of "immediate ex vivo" (IEV) isolates, analysed without culture adaption, in a region of relatively low malaria transmission. Using the HRP-2 and MSF methods, the 50% inhibitory concentration (IC50) values against a panel of malaria drugs were determined for P. falciparum reference clones (W2, D6, 3D7 and K1) and 41 IEV clinical isolates from an area of multidrug resistance in Cambodia. Comparison of the IC50 values from the two methods was made using Wilcoxon matched pair tests and Pearson's correlation. The lower limit of parasitaemia detection for both methods was determined for reference clones and IEV isolates. Since human white blood cell (WBC) DNA in clinical samples is known to reduce MSF assay sensitivity, SYBR Green I fluorescence linearity of P. falciparum samples spiked with WBCs was evaluated to assess the relative degree to which MSF sensitivity is reduced in clinical samples. IC50 values correlated well between the HRP-2 and MSF methods when testing either P. falciparum reference clones or IEV isolates against 4-aminoquinolines (chloroquine, piperaquine and quinine) and the quinoline methanol mefloquine (Pearson r = 0.85-0.99 for reference clones and 0.56-0.84 for IEV isolates), whereas a weaker IC50 value correlation between methods was noted when testing artemisinins against reference clones and lack of correlation when testing IEV isolates. The HRP-2 ELISA produced a higher overall success rate (90% for producing IC50 best-fit sigmoidal curves), relative to only a 40% success rate for the MSF assay, when evaluating ex

  8. Improved diagnostic performance of a commercial anaplasma antibody competitive enzyme-linked immunosorbent assay using recombinant major surface protein 5–glutathione S-transferase fusion protein as antigen

    Science.gov (United States)

    This study tested the hypothesis that removal of maltose binding protein from recombinant antigen used for plate coating would improve the specificity of Anaplasma antibody competitive ELISA. Three hundred and eight sera with significant MBP antibody binding (=30%I) in Anaplasma negative herds was 1...

  9. Collecting Societies, Competition and the Services Directive

    DEFF Research Database (Denmark)

    Riis, Thomas

    2011-01-01

    The market for collective management of copyrights in the EU is in transition and the collecting societies are facing a number of challenges primarily based on the EU rules on competition and the freedom to provide services. Some of the major right holders are withdrawing their rights from...... the system of reciprocal representation agreements which fragments the repertoire. This is partly due to the market evolution and the emergence of new business models but also promoted by the European Commission initiatives intended to introduce a certain degree of competition in the collective management...... the harms to cultural diversity. In addition to the competition law complications, the Services Directive puts significant restrictions on the member states to adopt or maintain national rules for collecting societies and that creates an urgent need for adopting a framework directive for collecting...

  10. Indirect enzyme-linked immunosorbent assay for the mycotoxin zearalenone.

    Science.gov (United States)

    Liu, M T; Ram, B P; Hart, L P; Pestka, J J

    1985-01-01

    A competitive indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of zearalenone, an estrogenic mycotoxin. Zearalenone was converted to zearalenone-6'-carboxymethyloxime and conjugated to bovine serum albumin and poly-L-lysine for use as immunogen and solid-phase marker, respectively. Immunization of rabbits with the bovine serum albumin conjugate resulted in zearalenone antibody titers of 20,480 in 11 weeks. A competitive indirect ELISA was conducted by simultaneously incubating zearalenone with zearalenone antiserum over zearalenone-6'-carboxymethyloxime poly-L-lysine solid phase and then determining the bound rabbit immunoglobulin with goat anti-rabbit peroxidase conjugate. Response range for zearalenone in the resulting competition curve was between 1 and 50 ng/ml. Reactivities of this antiserum for alpha-zearalenol, beta-zearalenol, alpha-zearalanol, and beta-zearalanol were, respectively, 50, 12, 6, and 3% of that found for zearalenone. By using the competitive indirect ELISA, zearalenone was detectable in methanol-water extracts of corn, wheat, and pig feed samples. PMID:2932054

  11. A competitive enzyme linked immunosorbent assay for the ...

    African Journals Online (AJOL)

    African Journal of Food, Agriculture, Nutrition and Development. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 10, No 9 (2010) >. Log in or Register to get access to full text downloads.

  12. Comparisons of competitive enzyme-linked immunosorbent assay ...

    African Journals Online (AJOL)

    Jane

    2011-07-18

    Jul 18, 2011 ... can be due to the reinfection of serum-positive cattle with heterogenous serotype of the virus (Billinis et al., 2001;. Bréard et al., 2005; Singer et al., 1998). On the other hand, it should be noted that in C-ELISA, anti-VP7 antibodies are traced. As it was mentioned earlier, this type of antibody does not have ...

  13. Species coexistence under resource competition with intraspecific and interspecific direct competition in a chemostat.

    Science.gov (United States)

    Saito, Yasuhisa; Miki, Takeshi

    2010-11-01

    Competition theory has developed separately for direct competition and for exploitative competition. However, the combined effects of the two types of competition on species coexistence remain unclear. To examine how intraspecific and interspecific direct competition contributes to the coexistence of species competing for a single resource, we constructed a chemostat-type resource competition model. With general functions for intraspecific and interspecific direct competition, we derived necessary and sufficient conditions (except for a critical case that rarely occurs in a biological sense) that determine the number of stably coexisting species. From these conditions, we found that the number of coexisting species is determined just by the invasibility of each species into subcommunities with a smaller number of species. In addition, using a combination of rigorous mathematical theory and a simple graphical method, we can demonstrate how the stronger intraspecific direct competition facilitates species invasion, leading to a larger number of coexisting species. Copyright 2010 Elsevier Inc. All rights reserved.

  14. Determination of histamine in Iranian cheese using enzyme-linked ...

    African Journals Online (AJOL)

    Determination of histamine in Iranian cheese using enzyme-linked immunosorbent assay (ELISA) method. Mojtaba Rashedi, Mohsen Panahi Dorcheh, Mohammad Salajegheh, Amin Mohammadi, Mohammad Reza Hajimirzaei, Ebrahim Rahimi ...

  15. An efficient direct competitive nano-ELISA for residual BSA determination in vaccines.

    Science.gov (United States)

    Wang, Qian-Long; Li, Jie; Li, Xing-De; Tao, Wan-Jun; Ding, Li-Sheng; Luo, Pei; Qing, Lin-Sen

    2017-07-01

    A simple, fast, and highly sensitive direct competitive enzyme-linked immunosorbent assay (ELISA) based on bovine serum albumin (BSA) antigen labeled amine-terminated silicon dioxide (SiO 2 -NH-BSA) nanoparticles was developed to determine residual BSA in vaccines. As nano-ELISA using nanomaterials with a very high surface-to-volume ratio has emerged as a promising strategy, SiO 2 -NH-BSA nanoparticles were prepared in this study by the coupling of BSA to SiO 2 nanoparticles modified with amidogen, followed by the quantification of BSA via a direct competitive binding of BSA-antigen-labeled SiO 2 nanoparticles to anti-BSA antibody conjugated with horseradish peroxidase. The validation study showed that the linear range of this method was from 1 to 90 ng/mL (r = 0.998) and the limit of detection was 0.67 ng/mL. The intra-assay and interassay coefficients of variation were less than 10% at three concentrations (10, 40, and 70 ng/mL), and the recovery was 92.4%, indicating good specificity. As a proof of principle, this new method was applied in the analysis of residual BSA in five different vaccines. Bland-Altman plots revealed that there was no significant difference in the accuracy and precision between our new method and the most commonly used sandwich ELISA. From the results taken together, the new method developed in this study is more sensitive and facile with lower cost and thus demonstrated potential to be applied in the quality control of biological products. Graphical Abstract Illustration of the procedures of the direct competitive enzyme immunoassay.

  16. Comparative application of antigen detection enzyme-linked ...

    African Journals Online (AJOL)

    Antigen-detection enzyme-linked immunosorbent assay (Ag-ELISA) and buffy coat parasitological technique (BCT) were employed for the diagnosis of bovine trypanosomiosis in trade cattle slaughtered at the Bodija Municipal abattoir in Ibadan, Oyo State, between March and November, 2002 and in some sedentary herds ...

  17. Designing of enzyme linked immunosorbent assay (ELISA) kit for ...

    African Journals Online (AJOL)

    The sensitivity of microscopic examination of fecal samples to recognize Giardia parasites is low. In the methods based on antigen scanning of parasites such as enzyme linked immunosorbent assay (ELISA), copro-antigens of parasite will be traced and diagnosed even if the live parasite is absent in the fecal samples.

  18. Development of an indirect enzyme-linked immunosorbent assay ...

    African Journals Online (AJOL)

    By removing the N-terminal hydrophobic sequence, truncated VP2 (tVP2) genes were cloned into the pET-32a (+) plasmid and subsequently expressed as His fusion proteins. The purified recombinant tVP2 proteins were specific to canine parvovirus (CPV), and one of them was used in an indirect enzyme-linked ...

  19. Comparison of agal gel precipitation test (AGPT) and enzyme linked ...

    African Journals Online (AJOL)

    The use of agar gel precipitation test (AGPT) and enzyme linked immunosorbent assay (ELISA) in assaying for the presence of infectious bursal disease (IBD) virus antibody in village chickens in Oyo State, Nigeria, was compared. Out of 400 sera subjected to ELISA, 360 (90%) samples where positive for IBD virus ...

  20. Determination of histamine in Iranian cheese using enzyme-linked ...

    African Journals Online (AJOL)

    john

    Determination of histamine in Iranian cheese using enzyme-linked immunosorbent assay (ELISA) method. Mojtaba Rashedi1*, Mohsen Panahi Dorcheh2, Mohammad Salajegheh2, Amin Mohammadi2,. Mohammad Reza Hajimirzaei2 and Ebrahim Rahimi1,3. 1Young Researchers Club, Faculty of Veterinary Medicine, ...

  1. Foreign Direct Investment, Competition and Industry Performance

    DEFF Research Database (Denmark)

    Bitzer, Jürgen; Görg, Holger

    2009-01-01

    This paper investigates the productivity effects of inward and outward foreign direct investment using industry- and country-level data for 17 OECD countries over the period 1973 to 2001. Controlling for national and international knowledge spillovers we argue that the effects of FDI work through...

  2. Electrochemical enzyme-linked immunoassay in a DNA hybridization sensor

    Czech Academy of Sciences Publication Activity Database

    Paleček, Emil; Kizek, René; Havran, Luděk; Billová, Sabina; Fojta, Miroslav

    2002-01-01

    Roč. 469, č. 1 (2002), s. 73-83 ISSN 0003-2670 R&D Projects: GA ČR GV204/97/K084; GA ČR GA204/00/D049 Institutional research plan: CEZ:AV0Z5004920 Keywords : electrochemical sensor for DNA hybridization * enzyme-linked immunoassay of target DNA * magnetic beads with attached DNA probe Subject RIV: BO - Biophysics Impact factor: 2.114, year: 2002

  3. Smartphone instrument for portable enzyme-linked immunosorbent assays

    OpenAIRE

    Long, Kenneth D.; Yu, Hojeong; Cunningham, Brian T.

    2014-01-01

    We demonstrate the utilization of a smartphone camera as a spectrometer that is capable of measuring Enzyme Linked Immunosorbent Assays (ELISA) at biologically-relevant concentrations with the aid of a custom cradle that aligns a diffraction grating and a collimating lens between a light source and the imaging sensor. Two example biomarkers are assayed using conventional ELISA protocols: IL-6, a protein used diagnostically for several types of cancer, and Ara h 1, one of the principle peanut ...

  4. Development of an enzyme-linked immunosorbent assay method to detect mustard protein in mustard seed oil

    NARCIS (Netherlands)

    Koppelman, S.J.; Vlooswijk, R.; Bottger, G.; Duijn, G. van; Schaft, P. van der; Dekker, J.; Bemgen, H. van

    2007-01-01

    An enzyme-linked immunosorbent assay for the detection of mustard protein was developed. The assay is based on a polyclonal antiserum directed against a mixture of mustard proteins raised in rabbits. The assay has a detection limit of 1.5 ppm (milligrams per kilogram) and is suitable for the

  5. Comparative study of indirect immunofluorescence, enzyme-linked immunosorbent assay, and the Tzanck smear test for the diagnosis of pemphigus.

    Science.gov (United States)

    Zhou, Tingting; Fang, Siyue; Li, Chunlei; Hua, Hong

    2016-11-01

    Pemphigus is one of the potentially fatal autoimmune blistering diseases. An early and accurate diagnosis is important for prognosis and therapy. It may be difficult to diagnosis based on clinical grounds alone. Direct and indirect immunofluorescence, enzyme-linked immunosorbent assay, the Tzanck smear test, or histopathology are all available for the diagnosis of pemphigus. However, there are no generally accepted diagnostic criteria for the diagnosis of this condition at present. To evaluate the diagnostic value of indirect immunofluorescence, enzyme-linked immunosorbent assay, and the Tzanck smear test for the diagnosis of pemphigus in dental clinics. A single-center retrospective study was conducted, and the clinical data of 33 patients with pemphigus and 61 controls were collected and analyzed from the Department of Oral Medicine, Peking University School of Stomatology, during 2010-2014. The sensitivities and specificities of indirect immunofluorescence, enzyme-linked immunosorbent assay, and the Tzanck smear test were calculated and compared in two groups. Sensitivities for the Tzanck smear test, indirect immunofluorescence, and enzyme-linked immunosorbent assay were 96.7%, 84.8%, and 84.8%, respectively, whereas the specificities of these tests were 60%, 91.8%, and 96.7%, respectively. The serial tests for the Tzanck smear test and enzyme-linked immunosorbent assay showed 82% sensitivity and 98.7% specificity. The serial test for the Tzanck smear test and enzyme-linked immunosorbent assay may represent a simple, rapid, and reliable way to definitive diagnosis of pemphigus. It is recommended as a common test for the diagnosis of pemphigus in dental clinics. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Lower and upper competitive bounds for online directed graph exploration

    OpenAIRE

    Foerster, Klaus-Tycho; Wattenhofer, Roger

    2015-01-01

    We study the problem of exploring all nodes of an unknown directed graph. A searcher has to construct a tour that visits all nodes, but only has information about the parts of the graph it already visited. Analogously to the travelling salesman problem, the goal is to minimize the cost of such a tour. In this article, we present upper and lower bounds for the competitive ratio of both the deterministic and the randomized online version of exploring all nodes of directed grap...

  7. Recombinant Diabody-Based Immunocapture Enzyme-Linked Immunosorbent Assay for Quantification of Rabies Virus Glycoprotein▿

    OpenAIRE

    Nimmagadda, Sridevi V.; Aavula, Shukra M.; Biradhar, Neelakantam; Rao, Varaprasada Sankarasetty; Shanmugham, Rajalakshmi; Chandran, Dev; Thirumeni, Nagarajan; Singanallur, Nagendrakumar Balasubramanian; Villuppanoor, Srinivasan Alwar

    2010-01-01

    The potency of rabies vaccines, determined using the NIH mouse protection test, can be directly correlated to the amount of rabies virus glycoprotein (RV GP) present in the vaccine. In an effort to develop a simple and sensitive enzyme-linked immunosorbent assay (ELISA) using recombinant diabody for quantification of RV GP, the variable heavy (VH) and light chain (VL) domains of an RV GP-specific human monoclonal antibody (MAb) secreted by a human × mouse heterohybridoma (human MAb R16E5) was...

  8. Enzyme-linked immunosorbent assays in murine cryptococcosis.

    Science.gov (United States)

    Scott, E N; Muchmore, H G; Felton, F G

    1981-12-01

    In this investigation, enzyme-linked immunosorbent assay (ElISA) procedures were used to study the time of appearance and the duration of demonstrable antigen and antibody in body fluids of mice with disseminated cryptococcosis. The ELISA antigen procedure detected cryptococcal capsular polysaccharide (CCP) in the serum and urine of infected mice 3 days after infection--4 days before it could be demonstrated by the latex agglutination procedure. ELISA-reactive antibody was present throughout the course of infection (mean death time, 32 days), whereas antibody was not detected by whole cell agglutination after day 20. High serum concentrations of CCP (titers to 64,000) persisted throughout the course of infection, while antibody declined to low levels with progression of disease. ELISA provides a sensitive system for quantitation and monitoring of antigen (CCP) processing and clearance (or storage), and for cryptococcal antibody formation in progressive cryptococcosis.

  9. Smartphone instrument for portable enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Long, Kenneth D; Yu, Hojeong; Cunningham, Brian T

    2014-11-01

    We demonstrate the utilization of a smartphone camera as a spectrometer that is capable of measuring Enzyme Linked Immunosorbent Assays (ELISA) at biologically-relevant concentrations with the aid of a custom cradle that aligns a diffraction grating and a collimating lens between a light source and the imaging sensor. Two example biomarkers are assayed using conventional ELISA protocols: IL-6, a protein used diagnostically for several types of cancer, and Ara h 1, one of the principle peanut allergens. In addition to the demonstration of limits of detection at medically-relevant concentrations, a screening of various cookies was completed to measure levels of peanut cross-contamination in local bakeries. The results demonstrate the utility of the instrument for quantitatively performing broad classes of homogeneous colorimetric assays, in which the endpoint readout is the color change of a liquid sample.

  10. Recombinant diabody-based immunocapture enzyme-linked immunosorbent assay for quantification of rabies virus glycoprotein.

    Science.gov (United States)

    Nimmagadda, Sridevi V; Aavula, Shukra M; Biradhar, Neelakantam; Rao, Varaprasada Sankarasetty; Shanmugham, Rajalakshmi; Chandran, Dev; Thirumeni, Nagarajan; Singanallur, Nagendrakumar Balasubramanian; Villuppanoor, Srinivasan Alwar

    2010-08-01

    The potency of rabies vaccines, determined using the NIH mouse protection test, can be directly correlated to the amount of rabies virus glycoprotein (RV GP) present in the vaccine. In an effort to develop a simple and sensitive enzyme-linked immunosorbent assay (ELISA) using recombinant diabody for quantification of RV GP, the variable heavy (V(H)) and light chain (V(L)) domains of an RV GP-specific human monoclonal antibody (MAb) secreted by a human x mouse heterohybridoma (human MAb R16E5) was amplified, linked using splicing by overlap extension PCR (SOE PCR), and expressed as a recombinant diabody (D06) in the pET28a bacterial expression system. The diabody D06 was purified by immobilized metal affinity chromatography on a nickel-nitrilotriacetic acid (NTA) agarose column and characterized. The purified diabody was used in combination with a well-characterized RV GP-specific mouse MAb, M5B4, to develop an immunocapture ELISA (IC-ELISA) for the quantification of RV GP in human rabies vaccine preparations. The maximum detection limit of the IC-ELISA using the M5B4-D06 combination was up to 31.25 ng/ml of RV GP. The specificity of the diabody was established by its nonreactivity toward other human viral antigens as determined by ELISA and toward RV GP as determined by immunoblot transfer assay and competitive ELISA with the parent human MAb R16E5 and MAb M5B4. The adjusted r(2) value obtained by the regression through the origin model was 0.902, and the equation for predicted potency values for M5B4-D06-based IC-ELISA and MAb M5B4 IC-ELISA were 0.5651x and 0.8044x, respectively, where x is the estimate of RV GP from the IC-ELISA in micrograms. Analysis of variance (ANOVA) results showed the estimates of the two methods differed significantly (P 0.05). The IC-ELISA can be readily adapted to measure the RV GP content in purified antigen, and a vaccine can be formulated based on the estimated GP.

  11. FISCAL COMPETITION AND DIRECT FOREIGN INVESTMENTS: ROMANIA VERSUS POLAND

    Directory of Open Access Journals (Sweden)

    Lazar Paula

    2012-12-01

    Full Text Available The European Economic Community treaty defines indirect taxation common rules taking into consideration their impact upon free merchandise’s circulation and upon international commercial exchanges. Once the Roma treaty has been signed (1957 the established scope was creating a common market. But, how is it possible to create a common market without any monetary and fiscal instruments? Thus, these instruments have had to be created in order to achieve such an objective. If from the monetary point of view introducing euro as a common currency was a big step ahead, from the fiscal point of view things haven’t evolved in such an easy manner. Fiscal objectives are achieved only if the national market is running normally and correctly. Indirect taxation is harmonized base upon article 113 from the European Union Treaty, while regarding direct taxation legal recommendations and regulations approval we can’t talk about harmonization but about fiscal competition. We are stating this because there are 27 states in the European Union and each one is sustaining its own direct taxation system. Furthermore, the taxation system (fiscal system is influencing member states economical performances through economies, investments and human capital formation by affecting the revenue’s distribution, research and development expenses level and type and by fiscal competition – an effect more and more profound. In this context we aim at analyzing the way fiscal competition had had a positive impact upon attracting foreign direct investments in Romania and Poland. We also aim at underlining positive and negative points for fiscal competition taking into consideration that not only a decrease in micro or macro-economic fiscal burden will have a positive impact upon investments in-flows and there are other factors to be taken into consideration, like: infrastructure, labor expenses

  12. Development of a solid-phase extraction-enzyme-linked immunosorbent assay for the determination of 17beta-19-nortestosterone levels in antifatigue functional foods.

    Science.gov (United States)

    Zhang, Yan; Pan, Tao; Fang, Guozhen; Ma, Dongyue; Wang, Shuo

    2009-10-01

    17beta-19-nortestosterone (17beta-NT) has been illegally used in antifatigue functional foods to promote muscle growth and improve endurance. A rapid and sensitive solid-phase extraction-enzyme-linked immunosorbent assay (SPE-ELISA) method was developed and successfully applied to analyze the levels of 17beta-NT in antifatigue functional foods. A polyclonal antibody against 17beta-NT was produced from rabbits immunized with the 17beta-NT-BSA conjugate, and a competitive direct enzyme-linked immunosorbent assay was developed for the rapid detection of 17beta-NT. The concentration causing 50% inhibition (IC(50)) and the limit of detection (LOD) were found to be 0.08 and 0.0055 ng/mL, respectively; this was better than methods previously reported that had a LOD of 2.4 ng/mL. C(18) cartridges were investigated for use in removing the effects of matrix in foods, and the sample purification protocol was optimized. Using the developed SPE-ELISA method, recoveries of functional food samples were obtained in the range of 71% to 91.5%. Moreover, 2 kinds of antifatigue functional foods were analyzed using the established ELISA and HPLC methods. The correlation coefficient of the results obtained using the 2 methods was greater than 0.98. Thus, the preliminary evaluation of the SPE-ELISA method proved that it is a specific, sensitive, and precise tool that can be used for the practical detection of 17beta-NT in various antifatigue functional food samples.

  13. Detection of copper ions using microcantilever immunosensors and enzyme-linked immunosorbent assay

    International Nuclear Information System (INIS)

    Zhao Hongwei; Xue Changguo; Nan Tiegui; Tan Guiyu; Li Zhaohu; Li, Qing X.; Zhang Qingchuan; Wang Baomin

    2010-01-01

    A sensitive and specific monoclonal antibody (designated as mAb6A9) recognizing a Cu(II)-ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA) complex but not metal-free EDTA was obtained by using an 1-(4-aminobenzyl)-EDTA-Cu(II) complex covalently coupled to a carrier protein as an immunogen to immunize the Balb/c mice. A mAb6A9-modified microcantilever sensor (MCS) was developed. A bending response was found to occur at or below 1 ng mL -1 of Cu(II)-EDTA complex. An indirect competitive enzyme-linked immunosorbent assay (icELISA) was developed with mAb6A9. The icELISA had a half maximum inhibition concentration and working range of approximately 1.8 and 0.2-17 ng mL -1 , respectively. The icELISA showed cross-reactivity of 18.8%, 1.1% and less than 1% with bivalent cobalt, mercury and other metals, respectively. The icELISA and functionalized MCSs were utilized to analyze the content of copper in spiked tap water samples. The assay conditions were optimized. The results of icELISA and MCS correlated well with those obtained by graphite furnace atomic absorption spectrometry.

  14. Investigation of grain competitive growth during directional solidification of single-crystal nickel-based superalloys

    International Nuclear Information System (INIS)

    Zhao, Xinbao; Liu, Lin; Zhang, Jun

    2015-01-01

    Grain competitive growth of nickel-based single-crystal superalloys during directional solidification was investigated. A detailed characterization of bi-crystals' competitive growth was performed to explore the competitive grain evolution. It was found that high withdrawal rate improved the efficiency of grain competitive growth. The overgrowth rate was increased when the misorientation increased. Four patterns of grain competitive growth with differently oriented dispositions were characterized. The results indicated that the positive branching of the dendrites played a significant role in the competitive growth process. The effect of crystal orientation and heat flow on the competitive growth can be attributed to the blocking mechanism between the adjacent grains. (orig.)

  15. Detection by enzyme-linked immunosorbent assay of Aujeszky's disease virus in tissues of infected pigs.

    OpenAIRE

    Qvist, P; Meyling, A; Hoff-Jørgensen, R

    1990-01-01

    An enzyme-linked immunosorbent assay was developed for the detection of Aujeszky's disease virus antigen in tissue extracts and in nasal swabs. The enzyme-linked immunosorbent assay is based on two different monoclonal antibodies with specificity for the gII glycoprotein of Aujeszky's disease virus. Viral antigen was detected in 81 of 93 tissue extracts prepared from virus-infected organs. Fifteen outbreaks of Aujeszky's disease were analyzed in this study, and they were all identified by the...

  16. Sandwich enzyme-linked immunosorbent assay for naringin.

    Science.gov (United States)

    Qu, Huihua; Wang, Xueqian; Qu, Baoping; Kong, Hui; Zhang, Yue; Shan, Wenchao; Cheng, Jinjun; Wang, Qingguo; Zhao, Yan

    2016-01-15

    Among the currently used immunoassay techniques, sandwich ELISA exhibits higher specificity, lower cross-reactivity, and a wider working range compared to the corresponding competitive assays. However, it is difficult to obtain a pair of antibodies that can simultaneously bind to two epitopes of a molecule with a molecular weight of less than 1000 Da. Naringin (Nar) is a flavonoid with a molecular mass of 580 Da. The main aim of this study was to develop a sandwich ELISA for detecting Nar. Two hybridomas secreting anti-Nar monoclonal antibodies (mAbs) were produced by fusing splenocytes from a mouse immunised against Nar-bovine serum albumin (BSA) conjugated with a hypoxanthine-aminopterin-thymidine (HAT)-sensitive mouse myeloma cell line; a sandwich ELISA for detecting Nar was developed using these two well-characterised anti-Nar mAbs. The performance of the sandwich assay was further evaluated by limit of detection (LOD), limit of quantification (LOQ), recovery, and interference analyses. A dose-response curve to Nar was obtained with an LOD of 6.78 ng mL(-1) and an LOQ of 13.47 ng mL(-1). The inter-assay and intra-assay coefficients of variation were 4.32% and 7.48%, respectively. The recovery rate of Nar from concentrated Fructus aurantii granules was 83.63%. A high correlation was obtained between HPLC and sandwich ELISA. These results demonstrate that the sandwich ELISA method has higher specificity for Nar than indirect competitive ELISA. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Application of an enzyme-linked immunosorbent assay (ELISA) to determine paraquat residues in milk, beef, and potatoes

    International Nuclear Information System (INIS)

    Van Emon, J.; Seiber, J.; Hammock, B.

    1987-01-01

    The USDA Food Safety and Inspection Service (FSIS) has included paraquat on its list of compounds to be considered for monitoring in foods. However, present methods do not easily accommodate the processing of large numbers of samples, thus limiting routine monitoring of the compound. The conventional method, based on spectrophotometry of reduced paraquat solutions, requires time-consuming sample preparation. Although the advantages of immunoassays for pesticide residue analysis have been pointed out, the reported immunoassays for paraquat have only been applied to cases of clinical poisoning or human exposure assessment. In this study, spiked milk, potato, and beef were analyzed directly, without prior cleanup, by an enzyme-linked immunosorbent assay (ELISA)

  18. Multiresidue Method for Analysis of β Agonists in Swine Urine by Enzyme Linked Receptor Assay Based on β2 Adrenergic Receptor Expressed in HEK293 Cells

    Science.gov (United States)

    Wang, Jian; She, Yongxin; Wang, Miao; Jin, Maojun; Li, Yongfei; Wang, Jing; Liu, Yuan

    2015-01-01

    A novel enzyme-linked receptor assay (ELRA) based on β2-adrenergic receptor (β2-AR) has been developed for rapid and high-throughput detection of β-adrenergic agonists (β-agonists) in urine. Human embryonic kidney cells (HEK293) were introduced as the expression system to enhance the functionality of the recombinant β2-AR, and the attempt to detect β-agonists in swine urine using such approaches was accomplished unprecedentedly. In this article, a recombinant porcine β2-AR was produced in the inner membrane of HEK293 cells and purified from crude membrane protein by nickel-nitrilotriacetic acid affinity chromatography. After activity identification, the recombinant receptor was used in the development of direct competitive ELRA. Several parameters such as blocking buffer and blocking process were optimized and the performance of the system was determined. The IC50 concentrations of clenbuterol, salbutamol, and ractopamine were 34, 53 and 63 μg/L, and the average recovery rates were 68.2%, 60.3% and 65.5%, respectively. ELRA based on β2-AR shows a series of advantages such as safety, easy operation, and high efficiency, making it promising for the rapid screening of β-agonists in animal urine. PMID:26422475

  19. Multiresidue Method for Analysis of β Agonists in Swine Urine by Enzyme Linked Receptor Assay Based on β2 Adrenergic Receptor Expressed in HEK293 Cells.

    Directory of Open Access Journals (Sweden)

    Jian Wang

    Full Text Available A novel enzyme-linked receptor assay (ELRA based on β2-adrenergic receptor (β2-AR has been developed for rapid and high-throughput detection of β-adrenergic agonists (β-agonists in urine. Human embryonic kidney cells (HEK293 were introduced as the expression system to enhance the functionality of the recombinant β2-AR, and the attempt to detect β-agonists in swine urine using such approaches was accomplished unprecedentedly. In this article, a recombinant porcine β2-AR was produced in the inner membrane of HEK293 cells and purified from crude membrane protein by nickel-nitrilotriacetic acid affinity chromatography. After activity identification, the recombinant receptor was used in the development of direct competitive ELRA. Several parameters such as blocking buffer and blocking process were optimized and the performance of the system was determined. The IC50 concentrations of clenbuterol, salbutamol, and ractopamine were 34, 53 and 63 μg/L, and the average recovery rates were 68.2%, 60.3% and 65.5%, respectively. ELRA based on β2-AR shows a series of advantages such as safety, easy operation, and high efficiency, making it promising for the rapid screening of β-agonists in animal urine.

  20. Rapid Determination of Ractopamine Residues in Edible Animal Products by Enzyme-Linked Immunosorbent Assay: Development and Investigation of Matrix Effects

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    2009-01-01

    Full Text Available To determine ractopamine residues in animal food products (chicken muscle, pettitoes, pig muscle, and pig liver, we established a rapid direct competitive enzyme-linked immunosorbent assay (ELISA using a polyclonal antibody generated from ractopamine-linker-BSA. The antibody showed high sensitivity and specificity in phosphate buffer, with an IC50 of 0.6 ng/mL, and the limit of detection was 0.04 ng/mL. The matrix effect of the samples was easily eliminated by one-step extraction with PBS, without any organic solution or clean-up procedure such as SPE or liquid-liquid extraction, making it a much more simple and rapid method than previously reported ones. The detection limit in blank samples was 0.2 μg/kg. To validate this new RAC (ractopamine hydrochloride ELISA, a RAC-free pig liver sample spiked at three different concentrations was prepared and analyzed by HPLC and ELISA. The results showed a good correlation between the data of ELISA and HPLC (R2>0.95, which proves that the established ELISA is accurate enough to quantify the residue of RAC in the animal derived foods.

  1. Rapid Determination of Ractopamine Residues in Edible Animal Products by Enzyme-Linked Immunosorbent Assay: Development and Investigation of Matrix Effects

    Science.gov (United States)

    Zhang, Yan; Wang, FengXia; Fang, Li; Wang, Shuo; Fang, GuoZhen

    2009-01-01

    To determine ractopamine residues in animal food products (chicken muscle, pettitoes, pig muscle, and pig liver), we established a rapid direct competitive enzyme-linked immunosorbent assay (ELISA) using a polyclonal antibody generated from ractopamine-linker-BSA. The antibody showed high sensitivity and specificity in phosphate buffer, with an IC50 of 0.6 ng/mL, and the limit of detection was 0.04 ng/mL. The matrix effect of the samples was easily eliminated by one-step extraction with PBS, without any organic solution or clean-up procedure such as SPE or liquid-liquid extraction, making it a much more simple and rapid method than previously reported ones. The detection limit in blank samples was 0.2 μg/kg. To validate this new RAC (ractopamine hydrochloride) ELISA, a RAC-free pig liver sample spiked at three different concentrations was prepared and analyzed by HPLC and ELISA. The results showed a good correlation between the data of ELISA and HPLC (R2 > 0.95), which proves that the established ELISA is accurate enough to quantify the residue of RAC in the animal derived foods. PMID:19826637

  2. Validation of 2 commercial Neospora caninum antibody enzyme linked immunosorbent assays

    Science.gov (United States)

    Wu, John T.Y.; Dreger, Sally; Chow, Eva Y.W.; Bowlby, Evelyn E.

    2002-01-01

    Abstract This is a validation study of 2 commercially available enzyme linked immunosorbent assays (ELISA) for the detection of antibodies against Neospora caninum in bovine serum. The results of the reference sera (n = 30) and field sera from an infected beef herd (n = 150) were tested by both ELISAs and the results were compared statistically. When the immunoblotting results of the reference bovine sera were compared to the ELISA results, the same identity score (96.67%) and kappa values (K) (0.93) were obtained for both ELISAs. The sensitivity and specificity values for the IDEXX test were 100% and 93.33% respectively. For the Biovet test 93.33% and 100% were obtained. The corresponding positive (PV+) and negative predictive (PV−) values for the 2 assays were 93.75% and 100% (IDEXX), and 100% and 93.75% (Biovet). In the 2nd study, competitive inhibition ELISA (c-ELISA) results on bovine sera from an infected herd were compared to the 2 sets of ELISA results. The identity scores of the 2 ELISAs were 98% (IDEXX) and 97.33% (Biovet). The K values calculated were 0.96 (IDEXX) and 0.95 (Biovet). For the IDEXX test the sensitivity and specificity were 97.56% and 98.53%, whereas for the Biovet assay 95.12% and 100% were recorded, respectively. The corresponding PV+ and PV− values were 98.77% and 97.1% (IDEXX), and 100% and 94.44% (Biovet). Our validation results showed that the 2 ELISAs worked equally well and there was no statistically significant difference between the performance of the 2 tests. Both tests showed high reproducibility, repeatability and substantial agreement with results from 2 other laboratories. A quality assurance based on the requirement of the ISO/IEC 17025 standards has been adopted throughout this project for test validation procedures. PMID:12418782

  3. DNA/DNA in situ hybridization with enzyme linked probes

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, S.; Mosher, M.; Charles, P.; Henry, S.; Taub, F.

    1987-05-01

    A non-radioactive in situ nucleic acid hybridization method which requires no antibodies, haptens, avidin or biotin intermediateries is presented. Horseradish peroxidase (HRP) labeled nucleic acid probes are hybridized in situ for 2 hours or less, followed by brief washing of hybridized cells and the direct detection of in situ hybrids with diaminobenzidine (DAB). Application of this method to the detection of Human Papilloma Virus (HPV) in human cells is shown.

  4. Detection of antibodies to the extractable nuclear antigens by enzyme linked immunosorbent assay

    International Nuclear Information System (INIS)

    Aziz, Khalil A.; Fzizal, Abul A.

    2005-01-01

    Anti-extractable nuclear antigen (ENA) antibodies are a group of autoantibodies that are directed against various components of the cell nucleus. Antibodies to these antigens are closely associated with connective tissue disease. Early diagnosis of these diseases can prove very difficult and therefore clinicians rely on the use of anti-ENA antibody testing for the exclusion. Old methods of testing are time consuming and require great skills. For these reasons clinical immunology laboratories are switching to testing for anti-ENA antibodies by enzyme linked immunosorbent assay (ELISA). The latter assays are more sensitive and require little skills. In the present study we have investigated a number of different ELISA preparations. The study was conducted at Birmingham Heartlands Hospital during the period 2003. We tested a number of ENA-positive and negative samples using 3 different commercial ELISA preparations and compared the results with traditional CCIE-assay. The present study revealed that some ELISA preparations can be more sensitive than CCIE method. Laboratories still using later method should switch to ELISA. However it is important that laboratories evaluate a long range of different ELISA preparations before selecting the most optimal one. In addition it is recommended that laboratories then audit results in order to determine true significance of such results. Finally until the true significance of ELISA generated results is known, positive ENA-results should be interpreted in conjunction with the clinical picture and this would require close liaison in between the clinical immunology laboratory and clinicians

  5. Enzyme-linked immunosorbent assays for insulin-like growth factor-I using six-histidine tag fused proteins

    International Nuclear Information System (INIS)

    Huang Yong; Shi Ruina; Zhong Xuefei; Wang Dan; Zhao Meiping; Li Yuanzong

    2007-01-01

    The fusion proteins of insulin-like growth factor-I (IGF-I) and six-histidine tag (IGF-I-6H, 6H-IGF-I-6H) were cloned, expressed, purified and renatured, with their immunoreaction properties and biological activities intact. The binding kinetics between these fusion proteins and anti-IGF-I antibody or anti-6H antibody were studied using surface plasmon resonance (SPR). Two enzyme-linked immunosorbent assay (ELISA) modes, which proved feasible in the measurement of human serum samples, were used to detect IGF-I with the help of the six-histidine tagged proteins. Furthermore, combining the production technique of the six-histidine tagged fusion protein with the competitive sandwich ELISA mode, using an enzyme labeled anti-6H antibody as a tracer, can be a universal immunochemical method to quantitate other polypeptides or proteins

  6. Intensity and direction of competitive anxiety as a function of goal attainment expectation and competition goal generation.

    Science.gov (United States)

    O'Brien, M; Hanton, S; Mellalieu, S D

    2005-12-01

    Jones's control model was adopted to investigate differences in the labelling of symptoms associated with pre-competition anxiety and self-confidence as a function of goal attainment expectation and competition goal generation. Team sport performers (N = 96) were divided into outcome, performance and process goal groups. Anxiety intensity and direction, and self-confidence were then examined as a function of goal expectancy (positive or negative) and perceived input into goal production (input or no input). MANOVA and follow-up ANOVA supported the study predictions. Specifically, participants who reported positive expectations of goal achievement and indicated some input into the goal generation process experienced the most facilitative interpretations of cognitive symptoms and greater self-confidence. The results highlight the need to consider how goals are generated when attempting to foster a sense of control and help athletes cope with the psychological demands of competition.

  7. Evaluation of an enzyme-linked immunosorbent assay for determination of porcine haptoglobin

    DEFF Research Database (Denmark)

    Petersen, H. H.; Nielsen, J. P.; Jensen, A.L.

    2001-01-01

    An enzyme-linked immunosorbent assay for quantification of haptoglobin in porcine serum was evaluated. Tbe detection limit when expressed as the estimated concentration of a blank sample was 0.0003 mg/ml. The precision of the assay was acceptable with intra-assay coefficients of variation below 4...

  8. Development of an Enzyme Linked Immunosorbent Assay to Detect Chicken Parvovirus Specific Antibodies

    Science.gov (United States)

    Here we report the development and application of an enzyme linked immunosorbent assay to detect parvovirus-specific antibodies in chicken sera. We used an approach previously described for other parvoviruses to clone and express viral structural proteins in insect cells from recombinant baculovirus...

  9. Comparison of five commercial anti-tetanus toxoid immunoglobulin G enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Perry, A L; Hayes, A J; Cox, H A; Alcock, F; Parker, A R

    2009-12-01

    Five commercially available enzyme-linked immunosorbent assays for the measurement of anti-tetanus toxoid immunoglobulin G (IgG) antibodies were evaluated for performance. The data suggest that there are manufacturer-dependent differences in sensitivity and accuracy for the determination of tetanus toxoid IgG antibodies that could result in different diagnostic interpretations.

  10. Diagnostic Potential of an Enzyme-Linked Immunospot Assay in Tuberculous Pericarditis

    NARCIS (Netherlands)

    Bathoorn, E.; Limburg, A.; Bouwman, J. J.; Bossink, A. W.; Thijsen, S. F.

    Tuberculous pericarditis is a rare disease in developed countries. The diagnosis is difficult to set since there are no robust rapid tests, and culture of pericardial fluid for Mycobacterium tuberculosis is often negative. T-SPOT. TB, an enzyme-linked immunospot (ELISPOT) test, measures the gamma

  11. Development of an enzyme-linked immunosorbent assay for seven sulfonamide residues and investigation of matrix effects from different food samples.

    Science.gov (United States)

    Zhang, Hongyan; Wang, Lei; Zhang, Yan; Fang, Guozhen; Zheng, Wenjie; Wang, Shuo

    2007-03-21

    Direct competitive enzyme-linked immunosorbent assays (ELISA) were developed to detect a broad range of sulfonamides in various matrices. Screening for this class of antibiotics in pig muscle, chicken muscle, fish, and egg extracts was accomplished by simple, rapid extraction methods carried out with only phosphate-buffered saline (PBS) buffer. Twenty milliliters of extract solution was added to 4 g of sample to extract the sulfonamide residues, and sample extracts diluted with assay buffer were directly analyzed by ELISA; matrix effects could be avoided with 1:5 dilution of pig muscle, chicken muscle, and egg extracts with PBS and 1:5 dilution of fish extract with 1% bovine serum albumin (BSA)-PBS. For liver sample, the extraction method was a little more complicated; 2 g of sample was added to 20 mL of ethanol, mixed, and then centrifuged. The solvent of 10 mL of the upper liquid was removed, and the residues were dissolved in 10 mL of PBS and then filtered; the filtrate was diluted two-fold with 0.5% BSA-PBS for ELISA. These common methods were able to detect seven sulfonamide residues such as sulfisozole, sulfathiazole, sufameter, sulfamethoxypyridazine, sulfapyridine, sulfamethizole, and sulfachlorpyridazine in pig muscle, liver, chicken muscle, egg, and fish. The assay's detection limits for these compounds were less than 100 microg kg-1. Various extraction methods were tested, and the average recovery (n=3) of 100 microg kg-1 for the matrices was found to range from 77.3 to 123.7%.

  12. EXTENDE MODEL OF COMPETITIVITY THROUG APPLICATION OF NEW APPROACH DIRECTIVES

    Directory of Open Access Journals (Sweden)

    Slavko Arsovski

    2009-03-01

    Full Text Available The basic subject of this work is the model of new approach impact on quality and safety products, and competency of our companies. This work represents real hypothesis on the basis of expert's experiences, in regard to that the infrastructure with using new approach directives wasn't examined until now, it isn't known which product or industry of Serbia is related to directives of the new approach and CE mark, and it is not known which are effects of the use of the CE mark. This work should indicate existing quality reserves and product's safety, the level of possible competency improvement and increasing the profit by discharging new approach directive requires.

  13. An enzyme-linked immunosorbent assay for detection of avian influenza virus subtypes H5 and H7 antibodies

    DEFF Research Database (Denmark)

    Jensen, Trine Hammer; Ajjouri, Gitte; Handberg, Kurt

    2013-01-01

    of this method. However, enzyme-linked immunosorbent assays (ELISAs) are being explored as an alternative test method.H5 and H7 specific monoclonal antibodies were experimentally raised and used in the development of inhibition ELISAs for detection of serological response specifically directed against AIV...... during experimental infection than the HI test did. The reproducibility of the ELISA’s performed at different times was high with Pearson correlation coefficients of 0.96-0.98. CONCLUSIONS: The ELISAs are a potential alternative to the HI test for screening of large amounts of avian sera, although only......BACKGROUND: Avian influenza virus (AIV) subtypes H5 and H7 attracts particular attention because of the risk of their potential pathogenicity in poultry. The haemagglutination inhibition (HI) test is widely used as subtype specific test for serological diagnostics despite the laborious nature...

  14. Highly specific detection of genetic modification events using an enzyme-linked probe hybridization chip.

    Science.gov (United States)

    Zhang, M Z; Zhang, X F; Chen, X M; Chen, X; Wu, S; Xu, L L

    2015-08-10

    The enzyme-linked probe hybridization chip utilizes a method based on ligase-hybridizing probe chip technology, with the principle of using thio-primers for protection against enzyme digestion, and using lambda DNA exonuclease to cut multiple PCR products obtained from the sample being tested into single-strand chains for hybridization. The 5'-end amino-labeled probe was fixed onto the aldehyde chip, and hybridized with the single-stranded PCR product, followed by addition of a fluorescent-modified probe that was then enzymatically linked with the adjacent, substrate-bound probe in order to achieve highly specific, parallel, and high-throughput detection. Specificity and sensitivity testing demonstrated that enzyme-linked probe hybridization technology could be applied to the specific detection of eight genetic modification events at the same time, with a sensitivity reaching 0.1% and the achievement of accurate, efficient, and stable results.

  15. Validation of a KHV antibody enzyme-linked immunosorbent assay (ELISA)

    DEFF Research Database (Denmark)

    Bergmann, S M; Wang, Q; Zeng, W

    2017-01-01

    fully validated for KHV. Therefore, it was developed and validated an enzyme-linked immunosorbent assay (ELISA) to detect KHV antibodies. The assay was optimized with respect to plates, buffers, antigens and assay conditions. It demonstrated high diagnostic and analytical sensitivity and specificity...... and was particularly useful at the pond or farm levels. Considering the scale of the carp and koi industry worldwide, this assay represents an important practical tool for the indirect detection of KHV, also in the absence of clinical signs....

  16. Can Direct and Indirect Taxes Be Added for International Comparisons of Competitiveness?

    OpenAIRE

    Hans-Werner Sinn

    1990-01-01

    While it is usually argued that direct and indirect taxes should be added for meaningful international comparisons of country competitiveness, this paper argues that the opposite may be true. It is possible that a country with a high value-added tax needs a high capital income tax to maintain its international competitiveness and vice verca. Which view is correct depends on which combination of the origin, destination, source and residence principles' prevail and whether or not accelerated de...

  17. Intensity and direction of competitive state anxiety as interpreted by rugby players and rifle shooters.

    Science.gov (United States)

    Hanton, S; Jones, G; Mullen, R

    2000-04-01

    This study reports the findings of part of an ongoing research program examining sports performers' interpretations of competitive anxiety prior to competition. The notion of 'directional perceptions' has questioned the limited utility of examining only the intensity of competitive anxiety responses as has Jones. The purpose of this study was to examine intensity and direction, i.e., interpretation of intensity as facilitative or debilitative, of anxiety symptoms as a function of two types of sport. The types of sport were explosive (rugby league) versus fine motor skills (target rifle shooting). The sample comprised 50 male rugby league participants and 50 target rifle shooters who completed a modified version of the Competitive State Anxiety Inventory-2 prior to competition. Contingency analysis yielded a significant difference in the number of rugby players who reported somatic anxiety as facilitative and the number of rifle shooters who reported somatic states as debilitative. No such differences were evident for cognitive anxiety. Analysis of variance indicated no differences between the two groups on the intensity of cognitive and somatic anxiety, but the performers competing in rugby league interpreted both states as being more facilitative to performance; the rugby league players also had higher scores on self-confidence than the shooters. These findings provide continuing support for the measurement of directional perceptions of competitive anxiety and highlight the importance of examining individual sports.

  18. Competition

    CERN Document Server

    Staff Association

    2016-01-01

      The Staff Association is organising a competition from 13 to 21 December 2016. There are several Go Sport vouchers to win with a value of 50 € each. Try your luck! To participate, you just have to be a member of the Staff Association and take the online quiz: https://ap-vote.web.cern.ch/content/jeu-concours-de-noel. The winners will be drawn among the correct answers.

  19. Competition

    CERN Document Server

    Staff Association

    2016-01-01

      The Staff Association is organising a competition from April 11 to 20. There are several Go Sport gift vouchers with a value of 50 € each to win. Try your luck! To participate, you just have to be a member of the Staff Association and take the online quiz: https://ap-vote.web.cern.ch/content/jeu-concours. The winners will be drawn among the correct answers.

  20. Competition

    CERN Multimedia

    Staff Association

    2017-01-01

    Get ready for the Easter Egg Hunt! The Staff Association is organising a competition from 10 to 21 April 2017. There are several Go Sport gift vouchers to win, with a value of 50 € each. Try your luck! Count the number of different eggs that we have hidden on our website. Then indicate your answer in the online form. To participate, you just need to be a member of the Staff Association. Winners will be randomly drawn among the correct answers.

  1. Development of enzyme-linked immunosorbent assays for the hepatotoxic alkaloids riddelliine and riddelliine N-oxide.

    Science.gov (United States)

    Lee, S T; Schoch, T K; Stegelmeier, B L; Gardner, D R; Than, K A; Molyneux, R J

    2001-08-01

    Pyrrolizidine alkaloid-containing plants are widely distributed throughout the world and are particularly common in the genus Senecio. The structural types and concentrations of the alkaloids vary among plant species. In addition, within a species of plant, concentrations vary with environment and location. Many pyrrolizidine alkaloids are toxic and cause poisoning in livestock and in humans. Rapid, sensitive, and specific diagnostic techniques are needed to identify poisoned animals and to determine the particular plants and conditions under which livestock are likely to be poisoned. In this study, two competitive inhibition enzyme-linked immunosorbent assays for riddelliine, riddelliine N-oxide, and other closely related pyrrolizidine alkaloids were developed using polyclonal antibodies. One assay is class specific toward the free base forms of the pyrrolizidine alkaloids; the other assay showed cross-reactivity to both the free base and N-oxide forms of the alkaloids. The assay with the lowest limit of detection had an I(50) of 803.9 pg with a limit of detection of 47.5 pg for riddelliine. Spike and recovery studies for riddelliine in bovine blood ranged from 45 to 74%. The assay that showed cross-reactivity between the N-oxide and free base forms of the pyrrolizidine alkaloids allowed estimation of the total pyrrolizidine alkaloid content in Senecio riddellii in admixture with alfalfa. These findings suggest that these techniques will be excellent tools to diagnose poisoned animals and identify highly toxic plants.

  2. Development of a Specifically Enhanced Enzyme-Linked Immunosorbent Assay for the Detection of Melamine in Milk

    Directory of Open Access Journals (Sweden)

    Yuanming Sun

    2011-06-01

    Full Text Available An indirect competitive enzyme-linked immunosorbent assay (icELISA with enhanced specificity for melamine in milk was developed. Three haptens of melamine with different spacer-arms were used to prepare different plate coating antigens. It was found that the icELISA show best sensitivity and specificity to melamine when using the coating antigen prepared by coupling 3-(4,6-diamino-1,6-dihydro-1,3,5-triazin-2-ylthiopropanoic acid (Hapten C with ovalbumin (OVA. The 50% inhibitory concentration (IC50 value was 35.4 ng·mL−1, the limit of detection (LOD was 8.9 ng·mL−1 and the detectable working range (20–80% inhibitory concentration was from 14.9 to 108.5 ng·mL−1, respectively. Compared to the ELISA results previously reported, the developed icELISA in the present study showed a much lower cross-reactivity to cyromazine, a fly-killing insecticide widely used in vegetables and stables. Recoveries obtained from milk samples in this study were in agreement with those obtained using the HPLC-MS method, indicating the detection performance of the icELISA could meet the requirement of the residue limit set by the Codex Alimentarius Commission. Therefore, the developed immunoassay can be applied for the analysis of melamine presented in milk.

  3. Enzyme-linked immunosorbent serum assays (ELISAs) for rat and human N-terminal pro-peptide of collagen type I (PINP) - Assessment of corresponding epitopes

    DEFF Research Database (Denmark)

    Leeming, Diana Julie; Larsen, D.V.; Zhang, C.

    2010-01-01

    Objectives: The present study describes two newly developed N-terminal pro-peptides of collagen type I (PINP) competitive enzyme-linked immunosorbent assays (ELISAs) for the assessment of corresponding PINP epitopes in the rat- and human species. Methods: Monoclonal antibodies were raised against...... corresponding rat and human PINP sequences and competitive assays were developed for each species. They were evaluated in relevant pre-clinical or clinical studies. Results: The antibody characterizations indicated that PINP indeed was recognized. Technical robust assays were obtained. Rat PINP and tALP showed...... similar patterns in the gold standard osteoporosis rat ovariectomized (OVX) model. No liver contribution was observed in the liver fibrosis rat bile duct ligation model (BDL). In an osteoporosis study, the human serum PINP levels were significantly decreased after ibandronate treatment compared to placebo...

  4. The use of subcutaneous fat tissue for amyloid typing by enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Olsen, K E; Sletten, K; Westermark, Per

    1999-01-01

    The amyloidoses are biochemically heterogeneous diseases with pathophysiologic deposits of various proteins. The clinical course, prognosis, and therapy are different for each type of amyloidosis and, therefore, a type-specific diagnosis is demanded as early as possible. We describe a method...... for typing the most common systemic amyloidoses of AL, AA, and transthyretin types by enzyme-linked immunosorbent assay (ELISA), using abdominal wall subcutaneous fat biopsy specimens. The method was tested on 21 abdominal fat biopsy specimens that were sent to the laboratory. Of these, 15 contained amyloid...

  5. EFL Learners' Use of Direct Strategies in Competitive and Cooperative Learning Contexts

    Science.gov (United States)

    Zarei, Abbas Ali; Layeq, Hamide

    2016-01-01

    This study investigated the effects of competitive and cooperative teaching techniques on Iranian adult EFL learners' use of direct strategies. To this end, a sample of 88 non-English major university students at Sohrevardi Nonprofit College in Qazvin were assigned to two groups, and each group received instruction under one of the treatment…

  6. Intensity and direction of competitive anxiety as a function of sport type and experience.

    Science.gov (United States)

    Mellalieu, Stephen D; Hanton, Sheldon; O'Brien, Michael

    2004-10-01

    Using Jones' (1995) model of control, intensity (level) and direction (interpretation) of symptoms associated with competitive trait anxiety were examined as a function of sport type and competitive experience. Participants from gross explosive and fine motor-skill sports (n = 162) completed a trait version of the Competitive State Anxiety Inventory-2 (Martens et al., 1990a) including intensity and direction subscales (Jones & Swain, 1992). Main effects for experience and sport type were reported with gross explosive sports indicating symptoms associated with competitive anxiety as more facilitative to performance than fine motor-skill sports. Experienced performers also reported more-facilitating interpretations of symptoms than their less-experienced counterparts. The findings provide support from a dispositional context to suggest that sport type and the level of competitive experience influence interpretation of symptoms usually experienced in pressure situations. Implementation of activation, relaxation or restructuring interventions contingent upon the nature of the sport is recommended with consideration of the development of confidence-building strategies in less-experienced performers.

  7. REGLEMENTED HARMONIZATION VS FISCAL COMPETITION IN THE FIELD OF DIRECT EUROPEAN TAXATION

    OpenAIRE

    Mihaela GÖNDÖR

    2011-01-01

    Starting from the objectives and the status of European tax harmonization and based on the research literature's studies, the paper formulates its own arguments pro tax competition and con total fiscal harmonization, with regard to direct taxation, by responding to some key questions: "Have indeed the national tax systems a negative effect on EU market integration in the absence of the total harmonization ?"; "Is direct tax harmonization critical to the operation of the Single Market ?" By us...

  8. Direct ELISA.

    Science.gov (United States)

    Lin, Alice V

    2015-01-01

    First described by Engvall and Perlmann, the enzyme-linked immunosorbent assay (ELISA) is a rapid and sensitive method for detection and quantitation of an antigen using an enzyme-labeled antibody. Besides routine laboratory usage, ELISA has been utilized in medical field and food industry as diagnostic and quality control tools. Traditionally performed in 96-well or 384-well polystyrene plates, the technology has expanded to other platforms with increase in automation. Depending on the antigen epitope and availability of specific antibody, there are variations in ELISA setup. The four basic formats are direct, indirect, sandwich, and competitive ELISAs. Direct ELISA is the simplest format requiring an antigen and an enzyme-conjugated antibody specific to the antigen. This chapter describes the individual steps for detection of a plate-bound antigen using a horseradish peroxidase (HRP)-conjugated antibody and luminol-based enhanced chemiluminescence (ECL) substrate. The methodological approach to optimize the assay by chessboard titration is also provided.

  9. Biotin/avidin sandwich enzyme-linked immunosorbent assay for Culicidae mosquito blood meal identification

    Directory of Open Access Journals (Sweden)

    A. M. Marassá

    2008-01-01

    Full Text Available The knowledge of mosquitoes Culicidae host feeding patterns is basic to understand the roles of different species and to indicate their importance in the epidemiology of arthropod-borne diseases. A laboratory assay was developed aiming at standardizing the biotin-avidin sandwich enzyme-linked immunosorbent assay, which was unprecedented for mosquito blood meal identification. The enzyme-linked immunosorbent assay (ELISA activity was evaluated by the detection of titers on each sample of the 28 blood-fed Culex quinquefasciatus. In light of the high sensitivity that the technique permits, by means of small quantities of specific antibodies commercially provided and phosphatase substrate which reinforces additional dilutions, human and rat blood meals were readily identified in all laboratory-raised Culex quinquefasciatus tested. The assay was effective to detect human blood meal dilutions up to 1:4,096, which enables the technique to be applied in field studies. Additionally, the present results indicate a significant difference between the detection patterns recorded from human blood meal which corroborate the results of host feeding patterns.

  10. Response of rice genotypes to weed competition in dry direct-seeded rice in India.

    Science.gov (United States)

    Mahajan, Gulshan; Ramesha, Mugalodi S; Chauhan, Bhagirath S

    2014-01-01

    The differential weed-competitive abilities of eight rice genotypes and the traits that may confer such attributes were investigated under partial weedy and weed-free conditions in naturally occurring weed flora in dry direct-seeded rice during the rainy seasons of 2011 and 2012 at Ludhiana, Punjab, India. The results showed genotypic differences in competitiveness against weeds. In weed-free plots, grain yield varied from 6.6 to 8.9 t ha(-1) across different genotypes; it was lowest for PR-115 and highest for the hybrid H-97158. In partial weedy plots, grain yield and weed biomass at flowering varied from 3.6 to 6.7 t ha(-1) and from 174 to 419 g m(-2), respectively. In partial weedy plots, grain yield was lowest for PR-115 and highest for PR-120. Average yield loss due to weed competition ranged from 21 to 46% in different rice genotypes. The study showed that early canopy closure, high leaf area index at early stage, and high root biomass and volume correlated positively with competitiveness. This study suggests that some traits (root biomass, leaf area index, and shoot biomass at the early stage) could play an important role in conferring weed competitiveness and these traits can be explored for dry-seeded rice.

  11. Early direct competition does not determine the community structure in a desert riparian forest.

    Science.gov (United States)

    Wu, Guilin; Jiang, Shaowei; Liu, Hui; Zhu, Shidan; Zhou, Duoduo; Zhang, Ying; Luo, Qi; Li, Jun

    2018-03-14

    In riparian zones along the Tarim River in northeastern China, the co-dominance by Populus euphratica and Tamarix ramosissima at the early succession stage shifts to P. euphratica dominance in the late stages. However, little is known about how this shift is mediated by the highly variable water conditions in riparian zones. Here we conducted a mesocosm experiment in which we measured the physiological and morphological traits of these two co-occuring species grown in mixtures under simulated favorable groundwater condition and no groundwater availability. Results indicated that T. ramosissima, in comparison to P. euphratica, had much lower WUE, less proportion of root biomass under favorable groundwater condition. Under no groundwater condition, T. ramosissima also showed higher maximal quantum yield of PSII which allowed it to accumulate higher aboveground and total biomass. Therefore, regardless of groundwater conditions, T. ramosissima exhibited superior competitive advantages against P. euphratica under direct competition condition, which demonstrates that the dominance shift was not resulted from the direct competition at seedling stage. Our findings further imply that a strategy of "sit and wait" in P. euphratica might favor its growth and survival when suffered flooding disturbances, thus allowing P. euphratica not being excluded through competition at early successional stage.

  12. 76 FR 16810 - Notice of Realty Action: Non-Competitive (Direct) Sale of Public Land in Hot Springs County, WY

    Science.gov (United States)

    2011-03-25

    ...] Notice of Realty Action: Non-Competitive (Direct) Sale of Public Land in Hot Springs County, WY AGENCY... land in Hot Springs County, Wyoming is being considered for non-competitive (direct) sale to Jim and... land in Hot Springs County, Wyoming has been examined and found suitable for sale under the authority...

  13. Development of an Enzyme-Linked Immunosorbent Assay Method Specific for the Detection of G-Group Aflatoxins.

    Science.gov (United States)

    Li, Peiwu; Zhou, Qian; Wang, Ting; Zhou, Haiyan; Zhang, Wen; Ding, Xiaoxia; Zhang, Zhaowei; Chang, Perng-Kuang; Zhang, Qi

    2015-12-28

    To detect and monitor G-group aflatoxins in agricultural products, we generated class-specific monoclonal antibodies that specifically recognized aflatoxins G₁ and G₂. Of the final three positive and stable hybridomas obtained, clone 2G6 produced a monoclonal antibody that had equal sensitivity to aflatoxins G₁ and G₂, and did not cross-react with aflatoxins B₁, B₂, or M₁. Its IC50 values for aflatoxins G₁ and G₂ were 17.18 ng·mL(-1) and 19.75 ng·mL(-1), respectively. Using this new monoclonal antibody, we developed a competitive indirect enzyme-linked immunosorbent assay (CI-ELISA); the method had a limit of detection of 0.06 ng·mL(-1). To validate this CI-ELISA, we spiked uncontaminated peanut samples with various amounts of aflatoxins G₁ and G₂ and compared recovery rates with those determined by a standard HPLC method. The recovery rates of the CI-ELISA ranging from 94% to 103% were comparable to those of the HPLC (92% to 102%). We also used both methods to determine the amounts of G-group aflatoxins in five peanut samples contaminated by aflatoxin B₁-positive, and their relative standard deviations ranged from 8.4% to 17.7% (under 20%), which demonstrates a good correlation between the two methods. We further used this CI-ELISA to assess the ability of 126 fungal strains isolated from peanuts or field soils to produce G-group aflatoxins. Among these, seven stains producing different amounts of G-group aflatoxins were identified. Our results showed that the monoclonal antibody 2 G6-based CI-ELISA was suitable for the detection of G-group aflatoxins present in peanuts and also those produced by fungi.

  14. Are stricter investment rules contagious? Host country competition for foreign direct investment through international agreements

    OpenAIRE

    Neumayer, Eric; Nunnenkamp, Peter; Roy, Martin

    2014-01-01

    We argue that the trend toward international investment agreements (IIAs) with stricter investment rules is driven by competitive diffusion, namely defensive moves of developing countries concerned about foreign direct investment (FDI) diversion in favor of competing host countries. Accounting for spatial dependence in the formation of bilateral investment treaties (BITs) and preferential trade agreements (PTAs) that contain investment provisions, we find that the increase in agreements with ...

  15. Enzyme-linked immunosorbent serum assay specific for the 7S domain of Collagen Type IV (P4NP 7S)

    DEFF Research Database (Denmark)

    Leeming, Diana J; Nielsen, Mette J; Dai, Yueqin

    2012-01-01

    Aim:  The present study describes the ability of a newly developed N-terminal pro-peptides of type IV collagen 7S domain (P4NP 7S) competitive enzyme-linked immunosorbent assay (ELISA) for describing liver fibrosis. The assay applies a monoclonal antibody specific for a PIVNP 7S epitope 100...... were significantly elevated in rat with liver fibrosis as seen by histology (CCL4: 283% elevated in the highest quartile of total hepatic collagen compared with controls, P = 0.001; BDL: 183% elevated at week 4 compared with sham, P type IV collagen...... expression in BDL rats (r = 0.49, P serum assay specific for P4NP 7S was highly related to liver fibrosis...

  16. A murine monoclonal antibody based enzyme-linked immunosorbent assay for almond (Prunus dulcis L.) detection.

    Science.gov (United States)

    Su, Mengna; Venkatachalam, Mahesh; Liu, Changqi; Zhang, Ying; Roux, Kenneth H; Sathe, Shridhar K

    2013-11-13

    A sandwich enzyme-linked immunosorbent assay (ELISA) using anti-almond soluble protein rabbit polyclonal antibodies as capture antibodies and murine monoclonal antibody 4C10 as the detection antibodies was developed. The assay is specific and sensitive (3-200 ng almond protein/mL) for almond detection. The standardized assay is accurate (<15% CV) and reproducible (intra- and inter assay variability <15% CV). The assay did not register any cross-reactivity with the tested food matrices, suggesting the assay to be almond amandin specific. The assay could detect the presence of declared almond in the tested matched commercial samples. Further, the assay reliably detected the presence of almonds in the laboratory prepared food samples spiked with almond flour.

  17. An enzyme-linked immunosorbent assay for the convenient serodiagnosis of contagious equine metritis in mares.

    Science.gov (United States)

    Katz, J; Geer, P

    2001-01-01

    An enzyme-linked immunosorbent assay (ELISA) was developed for the serodiagnosis of contagious equine metritis (CEM), a sexually transmitted disease caused by Taylorella equigenitalis. Antigen preparation was simple, and antigens derived from both classical and atypical forms of T. equigenitalis enabled detection of antibody responses elicted in horses experimentally exposed to either form of the bacterium. Sera serially obtained from these horses from 0 to 63 days postexposure were tested by the traditional complement fixation test (CFT) for CEM and with the ELISA, using both antigens separately. There was close agreement between CFT and ELISA methodologies during the postexposure time period used to detect CEM serodiagnostically in regulatory animal health testing programs. Unlike the CFT, which requires an overnight incubation step, the ELISAs are more convenient and can be completed in 3 hours.

  18. Recombinant Plasmodium falciparum glutamate rich protein; purification and use in enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Dziegiel, Morten Hanefeld; Borre, M B; Jepsen, S

    1991-01-01

    A method for purification of a recombinant Plasmodium falciparum protein produced in E. coli and its use in an enzyme-linked immunosorbent assay (ELISA) is described. The cloned gene fragment encodes GLURP,489-1271 the carboxy-terminal 783 amino acid residue portion of a 1271 amino acid residue P....... falciparum glutamate rich protein (GLURP), with a molecular weight of 220 kilodalton. The protein is associated with all parasite stages in the human host. Examination of sera from 105 adult Liberians living in a malaria endemic area revealed anti-GLURP IgG antibodies in 98% of the sera. The recombinant...... New Guinea (MAD20) and Honduras (HB3) completely absorbed specific antibodies, indicating the presence of conserved epitopes produced by all isolates of P. falciparum. Recombinant GLURP489-1271 ELISA is sensitive and rapid, and therefore well-suited for sero-epidemiological studies, and for control...

  19. An enzyme-linked immunosorbent assay for bromodeoxyuridine incorporation using fixed microcultures

    International Nuclear Information System (INIS)

    Muir, D.; Varon, S.; Manthorpe, M.

    1990-01-01

    We report a quantitative method by which a single microculture can be examined for cell morphology; cell number; DNA synthesis; and expression of cell antigens. This method first involves measuring by enzyme-linked immunosorbent assay (ELISA) the total bromodeoxyuridine (BrdU) incorporation into DNA by monolayer microcultures. The BrdU-ELISA measurement was followed by simultaneous immunostaining for BrdU-positive nuclei and for a cytoplasmic antigen. The method was applied to the measurement of mitogen-induced proliferation of rat sciatic nerve Schwann cell and cerebral astroglia microcultures. The ELISA measurement of BrdU incorporation compares favorably with measurements of tritiated thymidine incorporation and offers the additional advantages that the same microculture can subsequently be examined for cell number, for cell morphology, and for the percentage of cells having BrdU-labeled nuclei and other antigens

  20. An enzyme-linked immunosorbent assay for bromodeoxyuridine incorporation using fixed microcultures

    Energy Technology Data Exchange (ETDEWEB)

    Muir, D.; Varon, S.; Manthorpe, M. (Univ. of California, San Diego, La Jolla (USA))

    1990-03-01

    We report a quantitative method by which a single microculture can be examined for cell morphology; cell number; DNA synthesis; and expression of cell antigens. This method first involves measuring by enzyme-linked immunosorbent assay (ELISA) the total bromodeoxyuridine (BrdU) incorporation into DNA by monolayer microcultures. The BrdU-ELISA measurement was followed by simultaneous immunostaining for BrdU-positive nuclei and for a cytoplasmic antigen. The method was applied to the measurement of mitogen-induced proliferation of rat sciatic nerve Schwann cell and cerebral astroglia microcultures. The ELISA measurement of BrdU incorporation compares favorably with measurements of tritiated thymidine incorporation and offers the additional advantages that the same microculture can subsequently be examined for cell number, for cell morphology, and for the percentage of cells having BrdU-labeled nuclei and other antigens.

  1. Diagnosis of selected tropical diseases (Shistosomiasis and Malaria) using the enzyme-linked immunosorbent assays

    International Nuclear Information System (INIS)

    Chembe, E.

    1985-01-01

    Immunological reactions are commonly used in diagnostic procedures on the basis of their high levels of specificity and sensitivity. Antibodies or antigens labelled with various markers have been found to be particularly useful for assays of logical substances. The applications of Enzyme-Linked Immunoabsorbent Assays (ELISA) to research on various tropical and non-tropical diseases is now well established. The procedure depends on the labelling of one of the reactants with enzymes which can be detected accurately by an appropriate substrate. The detection mechanism depends on the labelling of one of the reactants in such a way that their their reactivity is not impaired or affected. In the present study, ELISA was applied to sera from kampumbu area of Isoka district in the Northern province of Zambia. The objective of this presentation is to show the relative positivity rate for antigen and antibody and the endemicity of schistosomiasis and malaria as assessed by classical parasitological procedures. (author)

  2. Bisphenol A determination in baby bottles by chemiluminescence enzyme-linked immunosorbent assay, lateral flow immunoassay and liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Maiolini, Elisabetta; Ferri, Elida; Pitasi, Agata Laura; Montoya, Angel; Di Giovanni, Manuela; Errani, Ermanno; Girotti, Stefano

    2014-01-07

    Two immunoassays, a Lateral Flow ImmunoAssay (LFIA) based on colloidal gold nanoparticle labels and an indirect competitive chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA), were developed and a high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was optimized to assess the possible release of bisphenol A (BPA, 4,4'-isopropylidenediphenol) from different plastic baby bottles treated with simulating solutions. Coating conjugate concentration, anti-BPA antibody dilution, incubation time of the primary and secondary antibodies, and tolerance to different organic solvents were optimized to obtain the best performance of the ELISA with chemiluminescent end-point detection. The influence of different buffers on LFIA performance was also evaluated. Both methods showed good repeatability (mean CV value around 13%) and sensitivity. Reproducibility tests for CL-ELISA gave a mean CV value of about 25%. The IC50 and Limit of Detection (LOD) values of CL-ELISA were 0.2 and 0.02 ng mL(-1), respectively. The LOD of LFIA was 0.1 μg mL(-1). A LC-MS/MS method was also optimized. The separation was performed in a C18 column with a triple-quadrupole mass spectrometer with electrospray ionisation interface. The method showed a good linearity in the range 2 to 500 ng mL(-1), with a regression coefficient of 0.998. In the simulating solutions the detection and quantification limits, calculated by the signal to noise level of 3 (S/N = 3), were 5.8 ng mL(-1) and 17.4 ng mL(-1), respectively. This limit of quantification was about 3 and 35 times lower than the permitted limits set by the official method CEN/TS 13130-13 (0.05 μg mL(-1)) and by the Directive 2004/19/EC (0.6 μg mL(-1)), respectively. The methods were applied to determine BPA release from baby bottles, performing repeated procedures according to EU and national regulations. The results demonstrated that no BPA migration from the tested plastic materials occurred with only one

  3. Coping styles for trait shame and anxiety intensity and direction in competitive athletes.

    Science.gov (United States)

    Partridge, Julie A; Wiggins, Matthew S

    2008-12-01

    The purpose of the study was to assess if athletes who perceived their anxiety as debilitative to performance also scored higher on ratings of coping styles used to handle trait shame. The sample was comprised of 94 participants (males = 44, females = 50) ranging in age from 15 to 24 years (M = 18.8, SD = 2.3). Athletes in high school (n = 21) and college (n = 73) representing several sports were surveyed for this study. Competitive sport experience averaged 11 yr. (SD = 3.9) overall. The Competitive Trait Anxiety Inventory-2D was given to collect general anxiety perceptions related to the athlete's specific sport. The Compass of Shame Scale-Sport was administered to measure coping styles for trait shame responses connected with competitive sport experiences. The athletes were divided into Facilitative (n = 39) and Debilitative anxiety groups (n = 55) based on the overall direction of anxiety scores. Multivariate analysis of variance indicated no interaction, but did reveal significant main effects for sex and anxiety group. Univariate tests indicated significant differences for several of the shame and anxiety subscales based on sex and anxiety group.

  4. Para Sport Athletic Identity from Competition to Retirement: A Brief Review and Future Research Directions.

    Science.gov (United States)

    Guerrero, Michelle; Martin, Jeffrey

    2018-05-01

    The primary purpose of this article is to review the literature on para sport athletic identity and provide avenues for future research direction. First, the authors briefly describe the existing quantitative and qualitative research on para sport athletic identity and, thereby, illustrate the complexities para sport athletes experience regarding the way they describe their participation in competitive sport. Next, the authors describe how para sport athletes with acquired permanent disabilities and congenital disabilities face similar, yet unique, identity-related challenges. Finally, the authors argue that future researchers should consider examining para sport athletes' identity through narrative identity. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. The Emotional Competitions. Theoretical Contributions for their Inclusion in the Practice of the Cuban Directives

    Directory of Open Access Journals (Sweden)

    Nureidy Betancourt-Montoya

    2015-11-01

    Full Text Available The present article has as objective to develop the concept of emotional intelligence and the competitions to her associate as an option and possible solution to achieve an effective interaction between the directive and its followers. Taking like reference the studies of about the emotional intelligence developed by Goleman established the relationship that she has with manegerial perfomance. One works resonant leader's concept so much in function of the achievement of the harmony in the personal plane as in the exchange with their subordinates.

  6. RELEVANT DIRECTIONS FOR THE PRODUCTION OF COMPETITIVE CONSTRUCTION PRODUCTS ON THE BASIS OF INNOVATION

    Directory of Open Access Journals (Sweden)

    T. Yu. Levitskiy

    2017-01-01

    Full Text Available Objectives. The article substantiates the necessity for competitive innovative high-tech construction products at the present stage of modernisation of the construction industry and reveals some peculiarities of their manufacture.Methods. In the course of the research, a programme-targeted method was applied, underlying the development of a programme for the innovative development of construction production.Results. Relevant directions of innovative development of construction production are systematised. The world's application experience of a technical regulation parametric model for construction industry product manufacturing is generalised. In order to increase the level of innovative activity of construction organisations, a set of practical measures is proposed whose implementation will ensure the output of competitive building products to the market.Conclusion. Increasing the competitiveness of construction products is closely connected with the activation of innovative processes: the introduction of high technology (including resource-saving into production processes and the expansion of the output of innovative products with the best consumer properties capable of successfully competing on the market with foreign counterparts in the context of import substitution strategies. The modernisation of the construction industry on the basis of introduction of hightech production methods specifies new requirements to the professional competencies of personnel producing competitive building products. To solve the set problems, a tool for improving the management mechanism of the innovative activity of construction organisations was proposed, ensuring the integration of institutional and production conditions for the large-scale development of advanced technologies and production of science-intensive types of construction products. 

  7. Detection of Plasmodium Aldolase Using a Smartphone and Microfluidic Enzyme Linked Immunosorbent Assay

    Directory of Open Access Journals (Sweden)

    Nikhil S. Gopal

    2017-01-01

    Full Text Available Background. Malaria control efforts are limited in rural areas. A low-cost system to monitor response without the use of electricity is needed. Plasmodium aldolase is a malaria biomarker measured using enzyme linked immunosorbent assay (ELISA techniques. A three-part system using ELISA was developed consisting of a microfluidic chip, hand crank centrifuge, and a smartphone. Methods. A circular microfluidic chip was fabricated using clear acrylic and a CO2 laser. A series of passive valves released reagents at precise times based upon centrifugal force. Color change was measured via smartphone camera using an application programmed in Java. The microchip was compared to a standard 96-well sandwich ELISA. Results. Results from standard ELISA were compared to microchip at varying concentrations (1–10 ng/mL. Over 15 different microfluidic patterns were tested, and a final prototype of the chip was created. The prototype microchip was compared to standard sandwich ELISA (n=20 using samples of recombinant aldolase. Color readings of standard ELISA and microfluidic microchip showed similar results. Conclusion. A low-cost microfluidic system could detect and follow therapeutic outcomes in rural areas and identify resistant strains.

  8. An enzyme-linked immunosorbent assay for measuring GPIHBP1 levels in human plasma or serum

    DEFF Research Database (Denmark)

    Miyashita, Kazuya; Fukamachi, Isamu; Nagao, Manabu

    2018-01-01

    antibodies against GPIHBP1 and used the antibodies to establish a sandwich enzyme-linked immunosorbent assay (ELISA) to measure GPIHBP1 levels in human blood. Results: The GPIHBP1 ELISA was linear in the 8 to 500 pg/mL range and allowed the quantification of GPIHBP1 in serum and in pre- and post...... of triglyceride-rich lipoproteins. Objective: Because some GPI-anchored proteins have been detected in plasma, we tested whether GPIHBP1 is present in human blood and whether GPIHBP1 deficiency or a history of cardiovascular disease affected GPIHBP1 circulating levels. Methods: We developed 2 monoclonal......-heparin plasma (including lipemic samples). GPIHBP1 was undetectable in the plasma of subjects with null mutations in GPIHBP1. Serum GPIHBP1 median levels were 849 pg/mL (range: 740-1014) in healthy volunteers (n = 28) and 1087 pg/mL (range: 877-1371) in patients with a history of cardiovascular or metabolic...

  9. Sandwich Enzyme-Linked Immunosorbent Assay for Detecting Sesame Seed in Foods.

    Science.gov (United States)

    Koppelman, Stef J; Söylemez, Gülsen; Niemann, Lynn; Gaskin, Ferdelie E; Baumert, Joseph L; Taylor, Steve L

    2015-01-01

    Small amounts of sesame can trigger allergic reactions in sesame-allergic patients. Because sesame is a widely used food ingredient, analytical methods are needed to support quality control and food safety programs in the food industry. In this study, polyclonal antibodies against sesame seed proteins were raised, and an enzyme-linked immunosorbent assay (ELISA) was developed for the detection and quantification of sesame seed residue in food. A comparison was made between this ELISA and other assays, particularly focusing on recovery of sesame seed residue from different food matrices. The developed ELISA is sensitive with a lower limit of quantification of 0.5 ppm and shows essentially no cross-reactivity with other foods or food ingredients (92 tested). The ELISA has a good recovery for analyzing sesame-based tahini in peanut butter, outperforming one other test. In a baked bread matrix, the ELISA has a low recovery, while two other assays perform better. We conclude that a sensitive and specific ELISA can be constructed based on polyclonal antibodies, which is suitable for detection of small amounts of sesame seed relevant for highly allergic patients. Furthermore, we conclude that different food products may require different assays to ensure adequate quantification of sesame.

  10. Sandwich Enzyme-Linked Immunosorbent Assay for Detecting Sesame Seed in Foods

    Directory of Open Access Journals (Sweden)

    Stef J. Koppelman

    2015-01-01

    Full Text Available Small amounts of sesame can trigger allergic reactions in sesame-allergic patients. Because sesame is a widely used food ingredient, analytical methods are needed to support quality control and food safety programs in the food industry. In this study, polyclonal antibodies against sesame seed proteins were raised, and an enzyme-linked immunosorbent assay (ELISA was developed for the detection and quantification of sesame seed residue in food. A comparison was made between this ELISA and other assays, particularly focusing on recovery of sesame seed residue from different food matrices. The developed ELISA is sensitive with a lower limit of quantification of 0.5 ppm and shows essentially no cross-reactivity with other foods or food ingredients (92 tested. The ELISA has a good recovery for analyzing sesame-based tahini in peanut butter, outperforming one other test. In a baked bread matrix, the ELISA has a low recovery, while two other assays perform better. We conclude that a sensitive and specific ELISA can be constructed based on polyclonal antibodies, which is suitable for detection of small amounts of sesame seed relevant for highly allergic patients. Furthermore, we conclude that different food products may require different assays to ensure adequate quantification of sesame.

  11. Sandwich-dot enzyme-linked immunosorbent assay for the detection of canine distemper virus

    Science.gov (United States)

    Li, Zhi; Zhang, Yanlong; Wang, Huiguo; Jin, Jinhua; Li, Wenzhe

    2013-01-01

    A sandwich-dot enzyme-linked immunosorbent assay (dot ELISA) was developed for the detection of canine distemper virus (CDV). In 56 dogs suspected to have CD the rates of detection of CDV antigen in samples of blood lymphocytes and palpebral conjunctiva by dot ELISA and ELISA were, respectively, 91% (49/54) and 81% (44/54) for the lymphocyte samples and 88% (28/32) and 75% (24/32) for the conjunctival samples. The CDV detection limits were 10 ng/50 μL for dot ELISA and 40 ng/50 μL for ELISA. The reliability of dot ELISA relative to electron microscopy was 96% with 22 samples: all 21 samples in which CDV particles were observed by electron microscopy yielded positive results with dot ELISA; the single sample in which particles were not observed yielded false-positive results with dot ELISA. The results indicate that the dot ELISA developed can serve as a reliable rapid diagnostic test in suspected cases of CD and also be useful for epidemiologic surveillance of the disease. PMID:24124274

  12. Enzyme-linked immunosorbent assay and radioimmunoassay of serum pepsinogen A

    Energy Technology Data Exchange (ETDEWEB)

    Pals, G.; Meuwissen, S.G.M.; Frants, R.R.; Kostense, P.J.; Eriksson, A.W.; Raesaenen, V.

    1987-02-01

    The determination of serum pepsinogen A (=pepsinogen I) levels is of clinical importance in the study of duodenal ulcer, atrophic gastritis and gastric cancer. In the present study two different quantitative immunological techniques for serum pepsinogen A were compared: a radioimmunoassay (RIA) (Helsinki) and an enzyme-linked immunosorbent assay (ELISA) (Amsterdam). Serum samples of 177 subjects with various gastric diseases were tested in a double blind study. The correlation was excellent (r=0.954 in the range 0-760 ..mu..g/l and r=0.971 in the range 0-100 ..mu..g/l). The functional relationship between ELISA (x) and RIA (y), determined by weighted model II regression, was y=1.12x-0.54. Initially the use of goat anti-PGA in the ELISA resulted in falsely high values in about 10% of the individuals. This was caused by circulating antibodies cross-reacting with goat IgG. This artefact was eliminated by pre-incubation of all samples with non-immune goat serum.

  13. Enzyme-linked immunosorbent assay and radioimmunoassay of serum pepsinogen A

    International Nuclear Information System (INIS)

    Pals, Gerard; Meuwissen, S.G.M.; Frants, R.R.; Kostense, P.J.; Eriksson, A.W.; Raesaenen, Vesa

    1987-01-01

    The determination of serum pepsinogen A (=pepsinogen I) levels is of clinical importance in the study of duodenal ulcer, atrophic gastritis and gastric cancer. In the present study two different quantitative immunological techniques for serum pepsinogen A were compared: a radioimmunoassay (RIA) (Helsinki) and an enzyme-linked immunosorbent assay (ELISA) (Amsterdam). Serum samples of 177 subjects with various gastric diseases were tested in a double blind study. The correlation was excellent (r=0.954 in the range 0-760 μg/l and r=0.971 in the range 0-100 μg/l). The functional relationship between ELISA (x) and RIA (y), determined by weighted model II regression, was y=1.12x-0.54. Initially the use of goat anti-PGA in the ELISA resulted in falsely high values in about 10% of the individuals. This was caused by circulating antibodies cross-reacting with goat IgG. This artefact was eliminated by pre-incubation of all samples with non-immune goat serum. (author)

  14. Estimation of transfused red cell survival using an enzyme-linked antiglobulin test

    International Nuclear Information System (INIS)

    Kickler, T.S.; Smith, B.; Bell, W.; Drew, H.; Baldwin, M.; Ness, P.M.

    1985-01-01

    An enzyme-linked antiglobulin test (ELAT) method was developed to estimate survival of transfused red cells. This procedure is based on a principle analogous to that of the Ashby technique were antigenically distinct red cells are transfused and their survival studied. The authors compared the ELAT survival to the 51 Chromium method ( 51 Cr) in four patients. Three patients with hypoproliferative anemias showed T 1/2 by ELAT of 17.5, 18, and 17 days versus 18.5, 20, and 19 days by the 51 Cr method. A fourth patient with traumatic cardiac hemolysis had two studies performed. In this case, the ELAT showed a T 1/2 of 10 and 8.1 days while 51 Cr T 1/2 values were 11 and 10.5 days. The ELAT method for measuring red cell survival yielded data which agreed closely with the results of the 51 Cr method. Although 51 Cr is the accepted method for red cell survival, the ELAT method can be used to estimate transfused red cell survival

  15. Design considerations of a hollow microneedle-optofluidic biosensing platform incorporating enzyme-linked assays

    Science.gov (United States)

    Ranamukhaarachchi, Sahan A.; Padeste, Celestino; Häfeli, Urs O.; Stoeber, Boris; Cadarso, Victor J.

    2018-02-01

    A hollow metallic microneedle is integrated with microfluidics and photonic components to form a microneedle-optofluidic biosensor suitable for therapeutic drug monitoring (TDM) in biological fluids, like interstitial fluid, that can be collected in a painless and minimally-invasive manner. The microneedle inner lumen surface is bio-functionalized to trap and bind target analytes on-site in a sample volume as small as 0.6 nl, and houses an enzyme-linked assay on its 0.06 mm2 wall. The optofluidic components are designed to rapidly quantify target analytes present in the sample and collected in the microneedle using a simple and sensitive absorbance scheme. This contribution describes how the biosensor components were optimized to detect in vitro streptavidin-horseradish peroxidase (Sav-HRP) as a model analyte over a large detection range (0-7.21 µM) and a very low limit of detection (60.2 nM). This biosensor utilizes the lowest analyte volume reported for TDM with microneedle technology, and presents significant avenues to improve current TDM methods for patients, by potentially eliminating blood draws for several drug candidates.

  16. Reliability of soluble IL-2 receptor measurements obtained with enzyme-linked immunosorbent assay

    International Nuclear Information System (INIS)

    Akiyama, Mitoshi; Takaishi, Masatoshi; Murakami, Yoshie; Ueda, Ryuzo; Yamakido, Michio; Tsubokura, Tokuo.

    1989-09-01

    Using an enzyme-linked immunosorbent assay (ELISA), human soluble interleukin-2 receptors (IL-2R) were measured in the serum of patients with various autoimmune system diseases. To study the sensitivity and specificity of the assay, soluble IL-2Rs were measured in the culture supernatants and in the cell extracts of peripheral blood mononuclear cells activated with phytohemagglutinin (PHA), purified protein derivative of tuberculin, and allogeneic lymphocytes, as well as in the serum of patients with various collagen diseases. The results correlated well with reports from other laboratories. For example, when stimulated by PHA, the greatest amount of soluble IL-2Rs was produced at the fastest rate. In addition, soluble IL-2R levels in the serum of collagen disease patients were significantly higher than those in healthy persons, who themselves exhibited low levels of detectable soluble IL-2Rs. It is hoped that reliable ELISA measurements of soluble IL-2Rs in the serum of atomic bomb survivors will assist in the interpretation of data collected during the work described in RP 2-87, a study of autoimmunity and autoimmune diseases in the Adult Health Study. (author)

  17. Measurement of Inflammatory Biomarkers in Synovial Tissue Extracts by Enzyme-Linked Immunosorbent Assay

    Science.gov (United States)

    Rosengren, Sanna; Firestein, Gary S.; Boyle, David L.

    2003-01-01

    We developed methods for measuring inflammatory biomarkers (cytokines, chemokines, and metalloproteinases) in synovial biopsy specimens from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Soluble extracts of synovial fragments were prepared with mild detergent and analyzed by enzyme-linked immunosorbent assay (ELISA) for interleukin 1β (IL-1β), IL-6, IL-8, tumor necrosis factor alpha (TNF-α), and matrix metalloproteinase 3. The optimal detergent was 0.1% Igepal CA-630, which interfered minimally with ELISA detection but extracted 80% of IL-6 from synovial tissue. Upon spiking, 81 to 107% of added biomarkers could be recovered. To determine within-tissue variability, multiple biopsy specimens from each RA synovial extract were analyzed individually. A resulting coefficient of variation of 35 to 62% indicated that six biopsy specimens per synovial extract would result in a sampling error of ≤25%. Preliminary power analysis suggested that 8 to 15 patients per group would suffice to observe a threefold difference before and after treatment in a serial biopsy clinical study. The previously described significant differences in IL-1β, IL-6, IL-8, and TNF-α levels between RA and OA could be detected, thereby validating the use of synovial extracts for biomarker analysis in arthritis. These methods allow monitoring of biomarker protein levels in synovial tissue and could potentially be applied to early-phase clinical trials to provide a preliminary estimate of drug efficacy. PMID:14607859

  18. A sensitive enzyme-linked immunosorbent assay for the determination of fish protein in processed foods.

    Science.gov (United States)

    Shibahara, Yusuke; Uesaka, Yoshihiko; Wang, Jun; Yamada, Shoichi; Shiomi, Kazuo

    2013-01-15

    Fish is one of the most common causes of food allergy and its major allergen is parvalbumin, a 12 kDa muscular protein. In this study, a sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of fish protein in processed foods was developed using a polyclonal antibody raised against Pacific mackerel parvalbumin. The developed sandwich ELISA showed 22.6-99.0% reactivity (based on the reactivity to Pacific mackerel parvalbumin) to parvalbumins from various species of fish. The limits of detection and quantitation were estimated to be 0.23 and 0.70 μg protein per g of food, respectively. When the sandwich ELISA was subjected to inter-laboratory validation, spiked fish protein was recovered from five model processed foods in the range of 69.4-84.8% and the repeatability and reproducibility relative standard deviations were satisfactorily low (≤ 10.5%). Thus, the sandwich ELISA was judged to be a useful tool to determine fish protein in processed foods. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Wax-Assisted One-Step Enzyme-Linked Immunosorbent Assay on Lateral Flow Test Devices.

    Science.gov (United States)

    Ishii, Masanori; Preechakasedkit, Pattarachaya; Yamada, Kentaro; Chailapakul, Orawon; Suzuki, Koji; Citterio, Daniel

    2018-01-01

    Lateral flow tests (LFTs) are widely used analytical tools characterized by portability, operator simplicity and short analysis times. A remaining challenge is their limited analytical sensitivity, which in classical immunoassay formats is overcome by enzyme-linked immunosorbent assay (ELISA) formats. The implementation of ELISA to an LFT format however, is hampered by the complexity of the procedure requiring the enzyme substrate addition after sample addition. In this work, a simple method for automation of this procedure without user interference is presented. Originally used sample pads of LFTs have been replaced by hydrophobic wax-modified filter paper-based sample pads to realize a delayed flow a pre-deposited colorimetric ELISA substrate without other alterations to the classical lateral-flow immunoassay format. The performance of the system has been characterized by visualizing flow behavior and final proof-of-concept is provided by a model mouse IgG assay, achieving a limit of detection of 15.8 ng mL -1 from just a single application of the sample solution.

  20. Enzyme-linked immunosorbent assay to quantitate serum ferritin in black and white ruffed lemurs (Varecia variegata variegata).

    Science.gov (United States)

    Andrews, Gordon A; Chavey, Patricia Sue; Crawford, Graham

    2005-12-01

    Lemurs in captivity progressively accumulate iron deposits in a variety of organs (hemosiderosis) including duodenum, liver, and spleen throughout their lives. When excessive, the toxic effects of intracellular iron on parenchymal cells, particularly the liver, can result in clinical disease and death. The pathogenesis of excessive iron storage in these species has been attributed to dietary factors related to diets commonly fed in captivity. Tissue iron stores can be directly estimated by tissue biopsy and histologic examination, or quantitated by chemical analysis of biopsy tissue, However, expense and risk associated with anesthesia and surgery prevent routine use of tissue biopsy to assess iron status. A noninvasive means of assessing total body iron stores is needed to monitor iron stores in lemurs to determine whether dietary modification is preventing excessive iron deposition, and to monitor potential therapies such as phlebotomy or chelation. Serum ferritin concentration correlates with tissue iron stores in humans, horses, calves, dogs, cats, and pigs. Serum ferritin is considered the best serum analyte to predict total body iron stores in these species and is more reliable than serum iron or total iron binding capacity, both of which may be affected by disorders unrelated to iron adequacy or excess including hypoproteinemia, chronic infection, hemolytic anemia, hypothyroidism, renal disease, and drug administration. We have developed an enzyme-linked immunosorbent assay to measure serum ferritin in lemurs. The assay uses polyclonal rabbit anti-human ferritin antibodies in a sandwich arrangement. Ferritin isolated from liver and spleen of a black and white ruffed lemur (Varecia variegata variegata) was used as a standard. Ferritin standards were linear from 0 to 50 microg/L. Recovery of purified ferritin from lemur serum varied from 95% to 110%. The within-assay variability was 4.5%, and the assay-to-assay variability for three different samples ranged

  1. Salivary Desmoglein Enzyme-Linked Immunosorbent Assay for Diagnosis of Pemphigus Vulgaris: A Noninvasive Alternative Test to Serum Assessment

    Directory of Open Access Journals (Sweden)

    Hossein Mortazavi

    2015-01-01

    Full Text Available Background. Serum desmoglein enzyme-linked immunosorbent assay (ELISA is used for the diagnosis and monitoring of pemphigus diseases. Objectives. To compare the diagnostic accuracy of salivary antidesmoglein (Dsg 1 and 3 ELISA in the diagnosis of pemphigus vulgaris (PV patients with that of serum desmogleins ELISA. Methods. Eighty-six untreated PV patients and 180 age- and sex-matched PV-free controls were recruited in this case-control study. PV was diagnosed based on clinical, histopathological, and direct immunofluorescence findings. After processing, serum and salivary anti-Dsg 1 and 3 were measured by the ELISA method using Euroimmun kit (Lübeck, Germany. Results. Using the cut-off point of 20 relative units (RU/mL, the serum anti-Dsg 1 and 3 ELISA were positive in 62 (72.1% and 83 (96.5% patients, respectively, and the salivary anti-Dsg 1 and 3 ELISA were positive in 31 (36.1% and 63 (73.3% patients, respectively. The specificity of salivary anti-Dsg 1 and anti-Dsg 3 were both 98.9%. Optimal cut-off values of 7.7 and 13.4 RU/mL were determined for the salivary anti-Dsg 1 and anti-Dsg 3 ELISA, respectively. Conclusion. Salivary anti-Dsg 1 and 3 ELISA with high specificities (98.9% could be suggested as safe and noninvasive methods for the diagnosis of PV when obtaining a blood sample is difficult.

  2. Development of an enzyme-linked immunosorbent assay for the detection of ciguatoxin in fish tissue using chicken immunoglobulin Y.

    Science.gov (United States)

    Empey Campora, Cara; Hokama, Yoshitsugi; Yabusaki, Kenichi; Isobe, Minoru

    2008-01-01

    A sandwich enzyme-linked immunosorbent assay was developed to detect ciguatoxin (CTX) in fish tissue. The assay utilizes two antibodies, chicken immunoglobulin Y specific to the ABCD domain of CTX and a mouse monoclonal immunoglobulin G-horseradish peroxidase conjugate specific to the JKLM domain of CTX. The sensitivity, working range, cross reactivity, accuracy, precision, and reproducibility were examined.

  3. Development and validation of an enzyme-linked immunosorbent assay for the quantification of trastuzumab in human serum and plasma

    NARCIS (Netherlands)

    Damen, Carola W. N.; de Groot, Els R.; Heij, Marianne; Boss, David S.; Schellens, Jan H. M.; Rosing, Hilde; Beijnen, Jos H.; Aarden, Lucien A.

    2009-01-01

    Trastuzumab, a humanized monoclonal antibody, is used for the treatment of breast cancer patients who overexpress the HER2 receptor. To optimize therapy, pharmacokinetic studies are necessary. The aim of this study was to develop an enzyme-linked immunosorbent assay (ELISA) for trastuzumab to

  4. An enzyme-linked immunosorbent assay for the detection of mouse polyomavirus-specific antibodies in laboratory mice.

    NARCIS (Netherlands)

    H.W.J. Broeders; J. Groen (Jan); A.D.M.E. Osterhaus (Albert); G. van Steenis (Bert)

    1994-01-01

    textabstractAn enzyme-linked immunosorbent assay (ELISA) was developed for the detection and quantification of IgM and IgG serum antibodies to mouse polyomavirus (MPV). To evaluate the potential of this ELISA for the screening of laboratory rodents, serum samples from specific pathogen free (SPF)

  5. Immunoglobulin G1 enzyme-linked Immunosorbent assay for diagnosis of Johne's disease in red deer (Cervus elaphus)

    NARCIS (Netherlands)

    Griffin, J.F.T.; Spittle, E.; Rodgers, C.R.; Liggett, S.; Cooper, M.; Bakker, D.; Bannantine, J.P.

    2005-01-01

    This study was designed to develop a customized enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Johne's disease (JD) in farmed deer. Two antigens were selected on the basis of their superior diagnostic readouts: denatured purified protein derivative (PPDj) and undenatured

  6. Quantification of patient specific assay interference in different formats of enzyme linked immunoassays for therapeutic monoclonal antibodies

    NARCIS (Netherlands)

    Grebenchtchikov, N.J.; Geurts-Moespot, A.; Heijmen, L.; Laarhoven, H.W.M. van; Herpen, C.M.L. van; Thijs, A.M.J.; Span, P.N.; Sweep, F.C.

    2014-01-01

    BackgroundThe use of therapeutic monoclonal antibodies for clinical purposes has significantly increased in recent years, and so has the need to monitor antibody concentrations. This may be achieved using the well-established enzyme linked immunoassay (ELISA) methods; however, these assays are

  7. Quantification of patient-specific assay interference in different formats of enzyme-linked immunoassays for therapeutic monoclonal antibodies

    NARCIS (Netherlands)

    Grebenchtchikov, Nicolai; Geurts-Moespot, Anneke J.; Heijmen, Linda; van Laarhoven, Hanneke W. M.; van Herpen, Carla M. L.; Thijs, Annemarie M. J.; Span, Paul N.; Sweep, Fred C. G. J.

    2014-01-01

    The use of therapeutic monoclonal antibodies for clinical purposes has significantly increased in recent years, and so has the need to monitor antibody concentrations. This may be achieved using the well-established enzyme linked immunoassay (ELISA) methods; however, these assays are subject to a

  8. Extraction procedure for sulfachloropyridazine in porcine tissues and detection in a sulfonamide-specific enzyme-linked immunosorbent assay (ELISA)

    NARCIS (Netherlands)

    Cliquet, P.; Cox, E.; Haasnoot, W.; Schacht, B.; Goddeeris, B.M.

    2003-01-01

    Sulfonamide-specific polyclonal rabbit antibodies were obtained after immunization with a sulfathiazole derivative (N1-[4-(carboxymethyl)-2-thiazolyl]sulfanilamide = TS) coupled to keyhole lympet hemocyanin. Using these antibodies, two sulfonamide-specific enzyme-linked immunosorbent assays (ELISAs)

  9. Development of a single-chain variable fragment-alkaline phosphatase fusion protein and a sensitive direct competitive chemiluminescent enzyme immunoassay for detection of ractopamine in pork

    Energy Technology Data Exchange (ETDEWEB)

    Dong Jiexian; Li Zhenfeng; Lei Hongtao; Sun Yuanming [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Ducancel, Frederic [CEA, iBiTec-S, Service de Pharmacologie et d' Immnoanalyse (SPI), CEA Saclay, F-91191 Gif sur Yvette (France); Xu Zhenlin [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Boulain, Jean-Claude [CEA, iBiTec-S, Service de Pharmacologie et d' Immnoanalyse (SPI), CEA Saclay, F-91191 Gif sur Yvette (France); Yang Jinyi; Shen Yudong [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China); Wang Hong, E-mail: gzwhongd@63.com [Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University, Guangzhou 510642 (China)

    2012-07-29

    Graphical abstract: Detection model of dc-CLEIA based on anti-RAC scFv-AP fusion protein. Highlights: Black-Right-Pointing-Pointer The scFv-AP fusion protein against ractopamine (RAC) was produced. Black-Right-Pointing-Pointer A dc-CLEIA for RAC was developed based on the purified scFv-AP fusion protein. Black-Right-Pointing-Pointer The sensitivity of dc-CLEIA was 10 times as sensitive as dc-ELISA for RAC. Black-Right-Pointing-Pointer Recovery tests from pork samples were studied. Black-Right-Pointing-Pointer Good accuracy was obtained. - Abstract: A rapid, sensitive chemiluminescent enzyme immunoassay (CLEIA) for ractopamine (RAC) based on a single-chain variable fragment (scFv)-alkaline phosphatase (AP) fusion protein was developed. The scFv gene was prepared by cloning the heavy- and light-chain variable region genes (V{sub H} and V{sub L}) from hybridoma cell line AC2, which secretes antibodies against RAC, and assembling V{sub H} and V{sub L} genes with a linker by means of splicing overlap extension polymerase chain reaction. The resulting scFv gene was inserted into the expression vector pLIP6/GN containing AP to produce the fusion protein in Escherichia coli strain BL21. The purified scFv-AP fusion protein was used to develop a direct competitive CLEIA (dcCLEIA) protocol for detection of RAC. The average concentration required for 50% inhibition of binding and the limit of detection of the assay were 0.25 {+-} 0.03 and 0.02 {+-} 0.004 ng mL{sup -1}, respectively, and the linear response range extended from 0.05 to 1.45 ng mL{sup -1}. The assay was 10 times as sensitive as the corresponding enzyme-linked immunosorbent assay based on the same fusion protein. Cross-reactivity studies showed that the fusion protein did not cross react with RAC analogs. DcCLEIA was used to analyze RAC spiked pork samples, and the validation was confirmed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). The results showed a good correlation between

  10. Relation between enzyme-linked immunosorbent assay and radioimmunoassay for detection of antibodies to the capsular polysaccharide of Haemophilus influenzae type b

    International Nuclear Information System (INIS)

    Kristensen, K.; Weis Bentzon, M.

    1992-01-01

    The measurement of antibodies to the capsular polysaccharide (PRP) of Haemophilus influenzae type b (Hib) is important because vaccines inducing such antibodies are now available. We developed and evaluated an enzyme-linked immunosorbent assay (ELISA) for detection of these antibodies based on direct coating of the plates with tyraminated PRP. The assay fulfilled the requirements for parallel line assays; it was sensitive, specific, and reproducible with a coefficient of variation between days of 19%. Results from the ELISA were compared with results from radioimmunoassay and a correlation coefficient of 0.93 was found. Results obtained by the two methods were proportional and the relation was indepenedent of the antibody level. The relation between them was also unaffected by the contribution of different antibody isotypes, indicating that these were measured to the same extent by both methods. ELISA employing direct coating of the plates with tyraminated PRP represents a useful alternative for detection of antibodies when studying immunogenicity of Hib vaccines. (au)

  11. Relation between enzyme-linked immunosorbent assay and radioimmunoassay for detection of antibodies to the capsular polysaccharide of Haemophilus influenzae type b

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, K. (Streptococcus Department, Statens Seruminstitut, Copenhagen (Denmark)); Weis Bentzon, M. (Department of Biostatistics, Statens Seruminstitut, Copenhagen (Denmark))

    1992-01-01

    The measurement of antibodies to the capsular polysaccharide (PRP) of Haemophilus influenzae type b (Hib) is important because vaccines inducing such antibodies are now available. We developed and evaluated an enzyme-linked immunosorbent assay (ELISA) for detection of these antibodies based on direct coating of the plates with tyraminated PRP. The assay fulfilled the requirements for parallel line assays; it was sensitive, specific, and reproducible with a coefficient of variation between days of 19%. Results from the ELISA were compared with results from radioimmunoassay and a correlation coefficient of 0.93 was found. Results obtained by the two methods were proportional and the relation was indepenedent of the antibody level. The relation between them was also unaffected by the contribution of different antibody isotypes, indicating that these were measured to the same extent by both methods. ELISA employing direct coating of the plates with tyraminated PRP represents a useful alternative for detection of antibodies when studying immunogenicity of Hib vaccines. (au).

  12. A novel marker for assessment of liver matrix remodeling: An enzyme-linked immunosorbent assay (ELISA) detecting a MMP generated type I collagen neo-epitope (C1M)

    DEFF Research Database (Denmark)

    Leeming, Diana Julie; He, Y.; Veidal, S. S.

    2011-01-01

    A competitive enzyme-linked immunosorbent assay (ELISA) for detection of a type I collagen fragment generated by matrix metalloproteinases (MMP) -2, -9 and -13, was developed (CO1-764 or C1M). The biomarker was evaluated in two preclinical rat models of liver fibrosis: bile duct ligation (BDL......) and carbon tetra chloride (CCL4)-treated rats. The assay was further evaluated in a clinical study of prostate-, lung-and breast-cancer patients stratified according to skeletal metastases. A technically robust ELISA assay specific for a MMP-2, -9 and -13 neo-epitope was produced and seen to be statistically...

  13. Comparison of two 3ABC enzyme-linked immunosorbent assays for diagnosis of multiple-serotype foot-and-mouth disease in a cattle population in an area of endemicity

    DEFF Research Database (Denmark)

    Bronsvoort, B.M.D.; Sørensen, K.J.; Anderson, J.

    2004-01-01

    . The nonstructural polyprotein 3ABC has recently been proposed as such an antigen, and a number of diagnostic tests are being developed. This paper evaluates the performance of two FMDV tests for antibodies to nonstructural proteins in an unvaccinated cattle population from a region of Cameroon with endemic multiple......-serotype FMD. The CHEKIT-FMD-3ABC bo-ov (CHEKIT) enzyme-linked immunosorbent assay (ELISA) (Bommeli Diagnostics/Intervet) is a commercially available test that was compared with a competitive 3ABC ELISA (C-ELISA) developed in Denmark. The tests were compared with the virus neutralization test as the "gold...

  14. Enzyme-linked immunosorbent assay for diagnosis of Amphimerus spp. liver fluke infection in Humans

    Directory of Open Access Journals (Sweden)

    William Cevallos

    Full Text Available BACKGROUND Amphimerus spp. is a liver fluke that infects humans and domestic animals. It is highly prevalent in some Ecuadorian communities. Currently, diagnosis is based on the microscopic observation of eggs in faeces, but this has variable sensitivity. More sensitive methods are needed for diagnostic testing. OBJECTIVE The main objective of this work was to develop an enzyme-linked immunosorbent assay (ELISA using crude antigens from Amphimerus spp. adult worms to detect anti-Amphimerus IgG in human sera. METHODS Crude somatic antigens were obtained from adult Amphimerus spp. worms. Human sera from 119 patients were tested: 48 from individuals with a confirmed Amphimerus spp. infection, 78 from non-infected Ecuadorians living in the endemic region, 60 from persons living in non-endemic areas (20 Ecuadorians, 20 Europeans, and 20 Africans, and 33 who had other parasitic and non-parasitic infections. PRINCIPAL FINDINGS Results were analysed using the receiver-operator characteristic (ROC curve analysis with an area under curve (AUC value of 0.967. The accuracy of the ELISA was high. The sensitivity was 85.0% [95% confidence interval (CI: 80.3-89.7%] and the specificity was 71.0% (95% CI: 65.2-76.8%. Some cross reactivity was detected against Paragonimus mexicanus, Fasciola hepatica, Schistosomiasis, Taenia solium, Strongyloides stercoralis, Mansonella spp., and Vampirolepis nana. MAIN CONCLUSIONS We have developed the first ELISA technique that detects anti-Amphimerus IgG in human sera with good sensitivity, repeatability and reproducibility. However, more specific antigens are needed to further enhance performance of this assay. Regardless, this ELISA test could be useful for early diagnosis and prompt treatment of human Amphimerus spp. infections.

  15. Enzyme-linked immunosorbent Assay for detecting of antibody to canine distemper virus

    Directory of Open Access Journals (Sweden)

    Sudarisman

    2006-03-01

    Full Text Available Serum neutralisation test (SNT has been established for evaluating canine distemper vaccination, but until now SNT was rarely used due to the need for continuous tissue culture facilities and requires 3 days to perform. For detecting antibody to canine distemper virus, an enzyme-linked immunosorbent assay (ELISA is relatively simple and rapid seroassay. ELISA for canine immunoglobulin (Ig G antibodies to canine distemper virus (CDV was developed by using Onderstepoort strain of canine distemper virus as coating antigen. Rabbit anti canine IgG labelled with horse radish peroxidase was used as the conjugate, while phenylenediamine dihydrochloride (OPD was used as the substrate. The ELISA results were then compared with the results of the SNT, using the sera of 312 random-source dogs from West Java. The two test-results had a high degree of correlation. Very few discrepancies occurred and most of these were at the lower limits of each test. When the sera were tested at 1 : 100 dilutions, there was a 95.5% agreement between the ELISA and SNT. Their sensitivity and spesificity were 83.9 and 98.4%. Titrated SNT and ELISA also were performed on sera from 7 dogs whose lifetime medical histories were known. The antibodies were inclining up after two months of post vaccination, where the titre was not in zero/lower position at the day of vaccination. However, antibody zero or low position were found at 28 days post vaccination. All of the results indicated that ELISA can be used for evaluating antibody to canine distemper virus response, replacing the SNT.

  16. Sandwich enzyme-linked immunosorbent assay (ELISA) for detection of cashew nut in foods.

    Science.gov (United States)

    Gaskin, Ferdelie E; Taylor, Steve L

    2011-01-01

    The presence of undeclared cashew can pose a health risk to cashew-allergic consumers. The food industry has the responsibility to declare the presence of cashews on packaged foods even when trace residues are or might be present. The objective of this study was to develop a rapid, sensitive, and specific enzyme-linked immunosorbent assay (ELISA) for the detection of cashew residues. Raw and roasted cashews were defatted and used separately to immunize sheep, goats, and rabbits. The cashew ELISA was developed using sheep and rabbit polyclonal anti-roasted cashew sera as capture and detector reagents, respectively, with visualization through an alkaline phosphatase-mediated substrate reaction. The cashew ELISA was shown to have a limit of quantification of 1 ppm (1 μg cashew/g). The ELISA was highly specific except that substantial cross-reactivity was noted with pistachio and a lesser degree of cross-reactivity was noted with hazelnut. The performance of the ELISA was assessed by manufacturing cookies, ice cream, and milk chocolate with added known amounts (0 to 1000 ppm) of cashew. The mean percent recoveries for ice cream, cookies, and milk chocolate were 118%± 2.9%, 84.3%± 4.0%, and 104%± 3.0%, respectively. In a limited retail survey, 4/5 retail samples with cashew declared on ingredient labels tested positive for cashew compared to 5/36 samples of foods with precautionary labels indicating the possible presence of one or more tree nuts and 0/18 samples without cashew declared on the label in any manner. The cashew ELISA can be used to detect undeclared cashew residue in foods and as a potential tool for the food industry to assess the effectiveness of allergen control strategies and to guarantee compliance with food labeling regulatory requirements. © 2011 Institute of Food Technologists®

  17. Helicobacter pylori-related gastroduodenal disease in children. Diagnostic utility of enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Glassman, M S; Dallal, S; Berezin, S H; Bostwick, H E; Newman, L J; Perez-Perez, G I; Blaser, M J

    1990-08-01

    To evaluate the accuracy of IgG and IgA serological tests in establishing a diagnosis of Helicobacter (Campylobacter) pylori gastric infection, 60 children presenting with chronic abdominal pain were prospectively studied. Endoscopic antral biopsies were obtained and analyzed for the presence of H. pylori using three standard methods: culture and identification of bacterial isolates, microscopic examination for morphologically characteristic bacteria, and urease production by the biopsy specimen. Concomitantly obtained serum samples were analyzed for the presence of IgG and IgA antibodies against H. pylori surface antigens using enzyme-linked immunosorbent assay (ELISA). Thirty-four of 60 (56.6%) had histological evidence of chronic active gastritis, eight of whom (13.3%) also had evidence of H. pylori infection by at least one criteria. Six of the eight infected patients had H. pylori demonstrated by all three methods. Of the eight infected patients, seven had IgG antibodies against H. pylori (sensitivity of 87%) and six had IgA antibodies (sensitivity of 75%). Among the six patients who had H. pylori infection confirmed by all three methods, all had IgG antibodies (sensitivity of 100%). In the patients without evidence of H. pylori infection, the IgG ELISA had a specificity of 96% (50/52), and the IgA ELISA had a specificity of 100% (52/52). Our data suggest that serological testing for the presence of antibodies against H. pylori may be a useful diagnostic tool in screening children with chronic abdominal pain for the presence of gastric infection with H. pylori.

  18. Two new automated, compared with two enzyme-linked immunosorbent, antimüllerian hormone assays.

    Science.gov (United States)

    Nelson, Scott M; Pastuszek, Ewa; Kloss, Grzegorz; Malinowska, Iwona; Liss, Joanna; Lukaszuk, Aron; Plociennik, Lukasz; Lukaszuk, Krzysztof

    2015-10-01

    To compare new automated antimüllerian hormone (AMH) assay performance characteristics from the new automated Elecsys AMH (Roche; Elecsys) and Access AMH (Beckman Coulter; Access) assays with the existing AMH Gen II ELISA (enzyme-linked immunosorbent assay; Gen II; Beckman Coulter) and AMH ELISA (Ansh Labs) assays. Prospective assay evaluation. University-affiliated clinical chemistry laboratory. Patients referred for serum AMH measurement (n = 83) before start of in vitro fertilization cycle between September 2014 and October 2014. None. Serum AMH concentration. Intra-assay coefficients of variation were low; Ansh ≤ 9.0%; Gen II ≤ 5.8%; Access ≤ 10.7%; and Elecsys ≤ 2.8%. The Passing-Bablok regression equations (pmol/L) were y (Access) = 0.128 + (0.781 × Gen II); and y (Access) = 0.302 + (0.742 x Ansh). For y (Elecys) = 0.087 + (0.729 x Gen II) and y (Elecys) = 0.253 + (0.688 x Ansh Labs). For y (Elecys) = 0.943 - (0.037 × Access). For all the assays, AMH exhibited a moderate positive correlation with AFC (r = 0.62-0.64); number of cumulus oocyte complexes (r = 0.60-0.64); and metaphase II oocytes (r = 0.48-0.50). Accuracy of pregnancy prediction, as determined by area under the receiver operating characteristic curve, was uniformly low for all assays (0.62-0.63). The novel automated assays exhibit strong concordance in calibration, but derived values are substantially lower than those obtained from pre-existing assays, with assay-specific interpretation required for routine clinical use. These results highlight the need for an international standard of measurement of AMH. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  19. Serum biotin in Japanese children: Enzyme-linked immunosorbent assay measurement.

    Science.gov (United States)

    Wakabayashi, Kenji; Kodama, Hiroko; Ogawa, Eishin; Sato, Yasuhiro; Motoyama, Kahoko; Suzuki, Mitsuyoshi

    2016-09-01

    Biotin deficiency has been reported in Japanese infants fed special formulas for medical reasons, including those with milk allergy and congenital metabolic diseases, because these formulas contain little biotin. Serum biotin measurement is useful for diagnosing biotin deficiency. We applied a simple and rapid method to analyze serum biotin, and established normal ranges for children and adults. Serum biotin in 188 healthy Japanese children aged 0-4 years and in 25 healthy adults was analyzed using a Biotin ELISA Kit (immundiagnostik). The effects of various conditions on the measurement of serum biotin were also examined. Median biotin in children aged 0-4 years was 10.4 ng/dL (IQR, 7.9-13.4 ng/dL), and that in adults was 12.9 ng/dL (IQR, 10.8-15.8 ng/dL). Normal range was 4.7-22.0 ng/dL in children and 8.4-20.5 ng/dL in adults (calculated using two-sided 95%CI). Measurements obtained with this method were not affected by frozen storage, freeze-thaw, or hemolysis, indicating that serum biotin can be analyzed accurately under these conditions, with a possible application to plasma samples. Serum biotin was significantly lower in children than in adults, with the normal range being 4.7-22.0 ng/dL in children and 8.4-20.5 ng/dL in adults. This simple and accurate enzyme-linked immunosorbent assay method is useful for diagnosing biotin deficiency. © 2016 The Authors. Pediatrics International published by John Wiley & Sons Australia, Ltd on behalf of Japan Pediatric Society.

  20. Assessment of Dextran Antigenicity of Intravenous Iron Preparations with Enzyme-Linked Immunosorbent Assay (ELISA

    Directory of Open Access Journals (Sweden)

    Susann Neiser

    2016-07-01

    Full Text Available Intravenous iron preparations are typically classified as non-dextran-based or dextran/dextran-based complexes. The carbohydrate shell for each of these preparations is unique and is key in determining the various physicochemical properties, the metabolic pathway, and the immunogenicity of the iron-carbohydrate complex. As intravenous dextran can cause severe, antibody-mediated dextran-induced anaphylactic reactions (DIAR, the purpose of this study was to explore the potential of various intravenous iron preparations, non-dextran-based or dextran/dextran-based, to induce these reactions. An IgG-isotype mouse monoclonal anti-dextran antibody (5E7H3 and an enzyme-linked immunosorbent assay (ELISA were developed to investigate the dextran antigenicity of low molecular weight iron dextran, ferumoxytol, iron isomaltoside 1000, ferric gluconate, iron sucrose and ferric carboxymaltose, as well as isomaltoside 1000, the isolated carbohydrate component of iron isomaltoside 1000. Low molecular weight iron dextran, as well as dextran-based ferumoxytol and iron isomaltoside 1000, reacted with 5E7H3, whereas ferric carboxymaltose, iron sucrose, sodium ferric gluconate, and isolated isomaltoside 1000 did not. Consistent results were obtained with reverse single radial immunodiffusion assay. The results strongly support the hypothesis that, while the carbohydrate alone (isomaltoside 1000 does not form immune complexes with anti-dextran antibodies, iron isomaltoside 1000 complex reacts with anti-dextran antibodies by forming multivalent immune complexes. Moreover, non-dextran based preparations, such as iron sucrose and ferric carboxymaltose, do not react with anti-dextran antibodies. This assay allows to assess the theoretical possibility of a substance to induce antibody-mediated DIARs. Nevertheless, as this is only one possible mechanism that may cause a hypersensitivity reaction, a broader set of assays will be required to get an understanding of the

  1. Diagnostic value of enzyme linked immuno-sorbent assay for cytomegalovirus disease.

    Directory of Open Access Journals (Sweden)

    Priya K

    2002-07-01

    Full Text Available BACKGROUND: Since interpretation of results of enzyme linked immuno-sorbent assay (ELISA for diagnosis of Cytomegalovirus (CMV infection in India is difficult, its diagnostic value required evaluation. AIMS: To evaluate the diagnostic value of ELISA against polymerase chain reaction (PCR in CMV disease. SETTINGS AND DESIGN: Results of ELISA test for CMV antibodies in CMV-DNA PCR positive and negative patients and normal healthy blood donors were analysed. METHODS AND MATERIAL: Anti-CMV antibodies were assayed by ELISA on the sera of 26 CMV PCR positive and 21 PCR negative patients and 35 normal healthy blood donors. STATISTICAL ANALYSIS: Chi square and Fischer exact test were used for statistical analysis. RESULTS: Anti-CMV antibodies (IgG or IgG and IgM were present in 20 (76.9% of 26 PCR positive and 13 (61.9% of 21 PCR negative patients. ELISA was negative in six (23.1% of 26 PCR positive patients. Of the 28 paediatric patients, ELISA was positive in 14 (73.7% of 19 PCR positive and three (33.3% of nine PCR negative patients showing a statistically significant difference (Chi square test, P value 0.038. Among the 19 patients having complications after organ transplant, ELISA showed anti-CMV antibodies in six (85.7% of seven PCR positive and 11 (91.7% of 12 PCR negative patients showing no significant difference. CMV-DNA was not detected in the buffy coat of 35 sero-positive blood donors. CONCLUSION: ELISA has no diagnostic value in the detection of CMV activation although it may help in the differential diagnosis of CMV infection in the paediatric age group.

  2. Competition of charge- versus radical-directed fragmentation of gas-phase protonated cysteine sulfinyl radicals.

    Science.gov (United States)

    Love, Chasity B; Tan, Lei; Francisco, Joseph S; Xia, Yu

    2013-04-24

    The fragmentation behavior of various cysteine sulfinyl ions (intact, N-acetylated, and O-methylated), new members of the gas-phase amino acid radical ion family, was investigated by low-energy collision-induced dissociation (CID). The dominant fragmentation channel for the protonated cysteine sulfinyl radicals ((SO•)Cys) was the radical-directed Cα-Cβ homolytic cleavage, resulting in the formation of glycyl radical ions and loss of CH2SO. This channel, however, was not observed for protonated N-acetylated cysteine sulfinyl radicals (Ac-(SO•)Cys); instead, charge-directed H2O loss followed immediately by SH loss prevailed. Counterintuitively, the H2O loss did not derive from the carboxyl group but involved the sulfinyl oxygen, a proton, and a Cβ hydrogen atom. Theoretical calculations suggested that N-acetylation significantly increases the barrier (~14 kcal mol(-1)) for the radical-directed fragmentation channel because of its reduced capability to stabilize the thus-formed glycyl radical ions via the captodative effect. N-Acetylation also assists in moving the proton to the sulfinyl site, which reduces the barrier for H2O loss. Our studies demonstrate that for cysteine sulfinyl radical ions, the stability of the product ions (glycyl radical ions) and the location of the charge (proton) can significantly modulate the competition between radical- and charge-directed fragmentation.

  3. Development of an enzyme-linked immunosorbent assay to determine the numbers of chemolithotrophic bacteria at acid-mine-drainage sites. Technical report (Final)

    Energy Technology Data Exchange (ETDEWEB)

    Blake, R.C.; Revis, N.W.; Holdsworth, G.

    1990-09-01

    Thiobacillus ferrooxidans is a prominent member of a group of chemo-lithotrophic bacteria that bear principal responsibility for the formation of acid mine drainage. A prototype enzyme-linked immunosorbent assay (ELISA) for enumerating and qualifying T. ferrooxidans was assembled and characterized. The immunoassay protocol consisted of sequential incubations of the sample with (i) the primary antibody, (ii) the enzyme-labeled secondary antibody, and (iii) a chromogenic substrate specific for the enzyme lable. The necessary reagents comprised primary polyclonal rabbit antibodies directed against T. ferrooxidans ATCC 23270, alkaline phosphatase-copled goat anti-rabbit polyclonal antibodies, and phenolphrhalein monophosphate. The ELISA developed herein correctly identified whether iron-oxidizing bacteria were present in each of 4 samples supplied and analyzed by an independent laboratory. Sufficient preliminary data was obtained to warrant further research and development activities.

  4. A simplification of the enzyme-linked immunospot technique. Increased sensitivity for cells secreting IgG antibodies to Haemophilus influenzae type b capsular polysaccharide

    DEFF Research Database (Denmark)

    Barington, T; Sparholt, S; Juul, L

    1992-01-01

    A simplified enzyme-linked immunospot (ELISPOT) technique is described for the detection of cells secreting antibodies to tetanus toxoid (TT), diphtheria toxoid (DT) or Haemophilus influenzae type b capsular polysaccharide (PRP). By combining the cell suspension with the enzyme-linked secondary...

  5. Competitive state anxiety and self-confidence: intensity and direction as relative predictors of performance on a golf putting task.

    Science.gov (United States)

    Chamberlain, Sean T; Hale, Bruce D

    2007-06-01

    This study considered relationships between the intensity and directional aspects of competitive state anxiety as measured by the modified Competitive Sport Anxiety Inventory-2(D) (Jones & Swain, 1992) in a sample of 12 experienced male golfers. Anxiety and performance scores from identical putting tasks performed under three different anxiety-manipulated competitive conditions were used to assess both the predictions of Multidimensional Anxiety Theory (MAT; Martens et al., 1990) and the relative value of intensity and direction in explaining performance variance. A within-subjects regression analysis of the intra-individual data showed partial support for the three MAT hypotheses. Cognitive anxiety intensity demonstrated a negative linear relationship with performance, somatic anxiety intensity showed a curvilinear relationship with performance, and self-confidence intensity revealed a positive linear relation. Cognitive directional anxiety illustrated a positive linear relationship with putting performance. Multiple regression analyses indicated that direction (42% of variance) was a better predictor of performance than intensity (22%).

  6. Detection of early antibodies in human immunodeficiency virus infection by enzyme-linked immunosorbent assay, Western blot, and radioimmunoprecipitation.

    OpenAIRE

    Saah, A J; Farzadegan, H; Fox, R; Nishanian, P; Rinaldo, C R; Phair, J P; Fahey, J L; Lee, T H; Polk, B F

    1987-01-01

    A current concept of the serological response to human immunodeficiency virus (HIV) infection in humans is that antibodies to core antigens (p55, p24, and p15) are detectable earlier during initial stages of antibody production than antibodies against envelope antigens (gp160, gp120, and gp41). Comparative studies of Western blot (immunoblot), radioimmunoprecipitation assay (RIPA), and enzyme-linked immunosorbent assay (ELISA) during initial antibody production are limited to case reports and...

  7. Comparison Between Direct-seeding and Transplanting of Rice in Mazandaran Province: Weed Competition, Yield and Yield Components

    Directory of Open Access Journals (Sweden)

    A Ala

    2014-12-01

    Full Text Available In order to investigate rice competition ability against weeds in direct-seeding and transplanting systems afield experiment was conducted at Mahmud Abad region of Mazandaran province on 2011 growing season. Experimental treatments were studied in a split plot factorial design based on randomized complete blocks with three replicates. Direct-seeding and transplanting of rice in wet seedbed were the main plots and three rice cultivars under two weed management systems (weed free and weed infested were arranged in sub plots. Results showed there was no significant yield difference in both system of rice planting under weed free condition, but yield loss due to weed interference in direct-seeding and transplanting of rice were 66% and 14% respectively.Line 843 which showed high competition ability in transplanting of rice, encountered with low ability due to weed pressure derivedweek early vigor but our traditional cultivar (Tarom Deilamani has acceptable competition ability and better yield sustainabilitythan improved cultivar (Khazar and line 843 in direct seeding system. Cultivars competitiveness could be attributed to more height, higher growth rate in early season, panicle number and higher dry weight of rice. Also in direct seeding related traits to the early vigor was more important than others. Results revealed that direct seeding integrated with weed control could be a good strategy for reducing costs of rice production. In such a system seedling early growth has important role in weed suppression.

  8. Development of a polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for detection of Sunset Yellow FCF in food samples.

    Science.gov (United States)

    Xing, Yue; Meng, Meng; Xue, Huyin; Zhang, Taichang; Yin, Yongmei; Xi, Rimo

    2012-09-15

    Sunset Yellow FCF is widely used as food additives to make foods more attractive. Due to its abuse and potential risk to human health, Sunset Yellow FCF is precisely limited to use in food. To monitor the illegal use of Sunset Yellow FCF, a polyclonal antibody-based indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) with satisfactory sensitivity and specificity was developed. A carboxyl group was introduced to Sunset Yellow FCF, then the modified hapten was coupled with carrier proteins to synthesize the immunogen and coating antigen. The IC(50) value of 0.52 ng mL(-1) and detection limit of 25 pg mL(-1) (in buffer) were achieved by this method. The cross-reactivity values of the antibodies with six structurally related colorants were less than 1.5%, indicating the high selectivity. Three kinds of food samples (beverage, dried beancurd, braised pork) and serum were chosen to evaluate the application of the immunoassay in real systems. The limits of detection (LOD) in the above three food samples were 0.12, 0.04 and 1.11, respectively (mean+3SD). The recovery (94%-106%), intra-assay (foods and serum samples were also acceptable. The results suggest that this ELISA method is a specific, sensitive and simple method for the determination of Sunset Yellow FCF additives. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Development of a nano-SiO2based enzyme-linked ligand binding assay for the determination of ibuprofen in human urine.

    Science.gov (United States)

    Wang, Qian-Long; Xie, Jing; Li, Xing-De; Ding, Li-Sheng; Liang, Jian; Luo, Pei; Qing, Lin-Sen

    2017-05-15

    The application domains of classic enzyme-linked ligand binding assay (ELBA) is relatively narrow due to the high cost and hardly available binding receptor. In here, we described for the first time the possibility of developing a new ELBA based on silica nanoparticles (nano-SiO 2 ) to assess the ibuprofen in human urine. Nano-SiO 2 with a large surface area was introduced as stationary phase to improve the analytical performance. In the experiment, a competitively binding procedure with human serum albumin (HSA) was performed between the ibuprofen presented in sample and horseradish peroxidase labeled ibuprofen (HRP-ibuprofen) subsequently added. After centrifugal separation, the HRP/ibuprofen/nano-SiO 2 composite catalyzed the substrate solution (TMB/H 2 O 2 ) with a color change from colorless to yellow for quantitative measurement via an ultraviolet spectrophotometer. As a validation of the new principle, the developed nano-ELBA method was applied in the determination of ibuprofen excreted in human urine with excellent performance. This detection range only depends on the solubility of ligand and sensitivity of UV spectrophotometer. Our results indicate that this new method demonstrated to be able to rapidly and adequately determine the concentration of components in biological samples and advocate its effectiveness for various applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Foreign direct investments in the role of strengthening the export competitiveness of the Serbian economy

    Directory of Open Access Journals (Sweden)

    Đurić Dejan

    2016-01-01

    Full Text Available The globalization of economic activity imposes the need for all countries to participate intensely in the current international economic cooperation and exchange processes of goods, services, labor and capital. Greater integration into international economic and trade flows is particularly important for small countries, given that the limitation of resources and insufficient domestic production impose the need for greater imports. On the other hand, import imposes a greater need for more exports so that the growing imports could be financed. Adjusting the challenges of globalization is an important task for all countries in order to accomplish basic economic goal, and that is the growth of living standards of all citizens. In this sense, in this paper, special attention is paid to the state of foreign trade and the analysis of the effects of FDI on export competitiveness and increase exports of the national economy, as one of the most important conditions of economic progress in the future. The main objective of this paper is to highlight the importance of the impact of foreign direct investments to strengthen the export activities of the Serbian economy, and the importance of intensification of export activity and qualitative changes in the structure of domestic exports.

  11. Competitive network determines the direction of the diversity–function relationship

    NARCIS (Netherlands)

    Maynard, Daniel S.; Crowther, Thomas W.; Bradford, Mark A.

    2017-01-01

    The structure of the competitive network is an important driver of biodiversity and coexistence in natural communities. In addition to determining which species survive, the nature and intensity of competitive interactions within the network also affect the growth, productivity, and abundances of

  12. Evaluation of immunofluorescence microscopy and enzyme-linked immunosorbent assay in detection of Cryptosporidium and Giardia infections in asymptomatic dogs

    DEFF Research Database (Denmark)

    Rimhanen-Finne, R.; Enemark, Heidi L.; Kolehmainen, J.

    2007-01-01

    The performance of immunofluorescence microscopy (IF) and enzyme-linked immunosorbent assay (ELISA) in canine feces was evaluated. IF and Cryptosporidium ELISA detected 10(5) oocysts/g, while the detection limit for Giardia ELISA was 10(4) cysts/g. The Cryptosporidium ELISA showed 94% specificity...... zoonotic character of Cryptosporidium and Giardia infections in 150 asymptomatic Finnish dogs from the Helsinki area were studied. The overall proportion of dogs positive for Cryptosporidium was 5% (7/150) and that for Giardia 5% (8/150). In dogs...

  13. Detection of immunoglobulin M and G antibodies against cytomegalovirus early and late antigens by enzyme-linked immunosorbent assay.

    OpenAIRE

    Middeldorp, J M; Jongsma, J; ter Haar, A; Schirm, J; The, T H

    1984-01-01

    A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) is described for the detection of immunoglobulin M and antibodies with specifity for human cytomegalovirus (CMV) early (CMV-EA) and late (CMV-LA) antigens. The emphasis is on the production of high-quality CMV antigens, CMV-EA and CMV-LA separately, and conditions for their application in the ELISA. The induction of CMV-EA and -LA in infected cell extracts was studied in detail by using human sera with defined antibody spe...

  14. A micro-enzyme-linked immunosorbent assay (ELISA) and radioimmunosorbent technique (RIST) for the detection of immunity to clinical tetanus

    International Nuclear Information System (INIS)

    Layton, G.T.

    1980-01-01

    Enzyme-linked immunosorbent assay (ELISA), and radioimmunosorbent assay (RIST) techniques for the detection of tetanus toxin antibodies are described. Both methods proved to be highly sensitive, and allowed the measurement of 5 x 10 -3 units/ml tetanus antitoxin in human serum or plasma, sensitivity and reproducibility comparing well with other techniques previously described, and being superior to haemagglutination and latex agglutination tests. Results of the two methods correlated well, and reflected the immunization histories obtained. Micro ELISA and micro RIST would seem to be suitable for the detection of immunity, or non-immunity to clinical tetanus. (author)

  15. Serodiagnosis of cutaneous leishmaniasis: assessment of an enzyme-linked immunosorbent assay using a peptide sequence from gene B protein

    DEFF Research Database (Denmark)

    Jensen, A T; Gaafar, A; Ismail, A

    1996-01-01

    An enzyme-linked immunosorbent assay (ELISA) using a 28 amino acid sequence of the repetitive element of gene B protein (GBP) from Leishmania major was developed for serodiagnosis of cutaneous leishmaniasis (CL). The assay was compared to ELISAs using crude amastigote and promastigote antigens from...... samples from healthy Sudanese individuals living in an area endemic for malaria but free of leish-maniasis were negative in all the assays. Significantly higher levels of antibodies were found in the patients who had suffered from the disease for more than eight weeks than in patients with a shorter...

  16. Markers of human immunodeficiency virus infection in high-risk individuals seronegative by first generation enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Pedersen, C; Lindhardt, B O; Lauritzen, E

    1989-01-01

    A total of 228 stored serum samples from 140 high risk individuals was examined for serological markers of human immunodeficiency virus (HIV) infection by second generation enzyme-linked immunosorbent assay, immunoblot, and HIV antigen assay. All the samples were negative in first generation enzyme...... are common in high risk individuals seronegative by first generation ELISA. However, HIV infection do occur in subjects negative by first generation ELISA, which emphasises the need for more sensitive screening assays and/or the use of antigen detection as part of screening in high risk individuals...

  17. Direct Agglutination Test and Enzyme Linked Immunosorbent Assay with Urine Samples for the Diagnosis of Visceral Leishma-niasis

    Directory of Open Access Journals (Sweden)

    Sarkari B

    2007-07-01

    Full Text Available Background: Visceral leishmaniasis (VL or Kala azar is an infectious disease caused by various species of Leishmania parasites. The aim of this study was to detect and compare the presence of anti-Leishmania antibodies in the urine of vis-ceral leishmaniasis patients using ELISA and DAT methods."nMethods: A total of 30 urine samples were collected from VL patients referred to Shiraz (southeast of Iran hospitals. Moreover 31 urine samples were collected from healthy individuals and patients with other diseases such as malaria, brucellosis, hydatidosis and cutaneous leishmaniasis. Collected samples were examined to detect anti-Leishmania antibod-ies in urine, using ELISA and DAT."nResults: Anti-Leishmania antibody was detected in urine of 18 out of 30 (60% VL patients by DAT while ELISA detected anti-Leishmania antibodies in urine of 28 out of 30 (93.3% of VL cases. Sensitivity and specificity of urine-based DAT was 60% and 83.9%, respectively while sensitivity and specificity of urine-based ELISA were 93.3% and 93.5%, corre-spondingly. "nConclusion: Urine-based DAT and ELISA have a reasonable specificity and sensitivity in diagnosis of VL. Accordingly, urine-based ELISA might be a suitable alternative for serum based assays for diagnosis of VL.

  18. Belowground Competition Directs Spatial Patterns of Seedling Growth in Boreal Pine Forests in Fennoscandia

    Directory of Open Access Journals (Sweden)

    E. Petter Axelsson

    2014-09-01

    Full Text Available Aboveground competition is often argued to be the main process determining patterns of natural forest regeneration. However, the theory of multiple resource limitation suggests that seedling performance also depends on belowground competition and, thus, that their relative influence is of fundamental importance. Two approaches were used to address the relative importance of above- and below-ground competition on regeneration in a nutrient-poor pine (Pinus sylvestris boreal forest. Firstly, seedling establishment beneath trees stem-girdled 12 years ago show that a substantial proportion of the seedlings were established within two years after girdling, which corresponds to a time when nutrient uptake by tree roots was severely reduced without disrupting water transport to the tree canopy, which consequently was maintained. The establishment during these two years also corresponds to abundances high enough for normal stand replacement. Secondly, surveys of regeneration within forest gaps showed that surrounding forests depressed seedlings, so that satisfactory growth occurred only more than 5 m from forest edges and that higher solar radiation in south facing edges was not enough to mediate these effects. We conclude that disruption of belowground competitive interactions mediates regeneration and, thus, that belowground competition has a strong limiting influence on seedling establishment in these forests.

  19. Hourly rate of direct labor - contributions to its applicability in the pricing process inserted in a competitive market

    Directory of Open Access Journals (Sweden)

    Antonio Benedito Silva Oliveira

    2016-12-01

    Full Text Available The detailed cost analysis is currently required as a result of increasingly competitive markets. The strategic cost management, analyzed from the optic of the target costing, can be a powerful tool for companies to keep themselves competitive. In this way, this study aimed to present a meticulous analysis of the hourly rate of direct labor in the pricing process of a new product, in order to understand if its use is appropriate in a pricing process. We used the deductive method supported in a case study, and the result achieved is that the hourly rate of direct current labor cannot be used in the pricing process, otherwise will be determined unrealistic costs to the product. It is important to highlight that this analysis applies to micro and small until large corporations.

  20. Expression and Characterization of Recombinant, Tetrameric and Enzymatically Active Influenza Neuraminidase for the Setup of an Enzyme-Linked Lectin-Based Assay.

    Directory of Open Access Journals (Sweden)

    Marua Prevato

    Full Text Available Developing a universal influenza vaccine that induces broad spectrum and longer-term immunity has become an important potentially achievable target in influenza vaccine research and development. Hemagglutinin (HA and neuraminidase (NA are the two major influenza virus antigens. Although antibody responses against influenza virus are mainly directed toward HA, NA is reported to be more genetically stable; hence NA-based vaccines have the potential to be effective for longer time periods. NA-specific immunity has been shown to limit the spread of influenza virus, thus reducing disease symptoms and providing cross-protection against heterosubtypic viruses in mouse challenge experiments. The production of large quantities of highly pure and stable NA could be beneficial for the development of new antivirals, subunit-based vaccines, and novel diagnostic tools. In this study, recombinant NA (rNA was produced in mammalian cells at high levels from both swine A/California/07/2009 (H1N1 and avian A/turkey/Turkey/01/2005 (H5N1 influenza viruses. Biochemical, structural, and immunological characterizations revealed that the soluble rNAs produced are tetrameric, enzymatically active and immunogenic, and finally they represent good alternatives to conventionally used sources of NA in the Enzyme-Linked Lectin Assay (ELLA.

  1. Analysis of larval antigens of Oestrus ovis for the diagnosis of oestrosis by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Alcaide, M; Reina, D; Frontera, E; Navarrete, I

    2005-06-01

    A serodiagnostic test for the diagnosis of infestation by the sheep nasal bot fly, Oestrus ovis (Linné) was examined. The enzyme-linked immunosorbent assay (ELISA) technique was used to analyze and compare the production of immunoglobulin G (IgG) antibodies against excretory-secretory products (ESP) and crude extract (CE) antigens from all the different larval stages of O. ovis in the sera of 276 adult sheep sampled in summer (n = 135) and winter (n = 141). ESP from first stage larvae was the most sensitive, coating antigen in winter and ESP from second stage larvae during summer. The most specific values were obtained by ESP against L1 in winter and by CE against L3 in summer. These results show that the stage of larval development has a significant impact on the humoral immune response over the course of a season. A significant correlation (P oestrosis immunodiagnosis.

  2. Immunodiagnosis of fascioliasis using sandwich enzyme-linked immunosorbent assay for detection of Fasciola gigantica paramyosin antigen

    Science.gov (United States)

    Abou-Elhakam, Hany Mohamed Adel; Bauomy, Ibraheem Rabia; El Deeb, Somaya Osman; El Amir, Azza Mohamed

    2013-01-01

    Background: Many immunological techniques have been developed over years using the different Fasciola antigens for diagnosis of parasitic infection and to replace the parasitological techniques, which are time consuming and usually lack sensitivity and reproducibility. Materials and Methods: In this study, Fasciola gigantica paramyosin (Pmy) antigen was early detected in cattle sera using sandwich enzyme-linked immunosorbent assay (ELISA), to evaluate the Pmy antigen performance in diagnosis. This work was conducted on 135 cattle blood samples, which were classified according to parasitological investigation into, healthy control (30), fascioliasis (75), and other parasites (30) groups. Results: The sensitivity of Sandwich ELISA was 97.33%, and the specificity was 95%, in comparison with parasitological examination, which recorded 66.66% sensitivity and 100% specificity, respectively. Conclusions: It was clear that the native F. gigantica Pmy is considered as a powerful antigen in early immunodiagnosis of fascioliasis, using a highly sensitive and specific sandwich ELISA technique. PMID:23961441

  3. Evaluation of a chemiluminescent enzyme-linked immunosorbent assay for the diagnosis of Trypanosoma cruzi infection in a nonendemic setting

    Directory of Open Access Journals (Sweden)

    Luis Izquierdo

    2013-11-01

    Full Text Available The disappearance of lytic, protective antibodies (Abs from the serum of patients with Chagas disease is accepted as a reliable indicator of parasitological cure. The efficiency of a chemiluminescent enzyme-linked immunosorbent assay based on a purified, trypomastigote-derived glycosylphosphatidylinositol-anchored mucin antigen for the serologic detection of lytic Abs against Trypanosoma cruzi was evaluated in a nonendemic setting using a panel of 92 positive and 58 negative human sera. The technique proved to be highly sensitive {100%; 95% confidence interval (CI = 96-100} and specific (98.3%; 95% CI = 90.7-99.7, with a kappa score of 0.99. Therefore, this assay can be used to detect active T. cruzi infection and to monitor trypanosomicidal treatment.

  4. An improved enzyme-linked immunosorbent assay for whole-cell determination of methanogens in samples from anaerobic reactors

    DEFF Research Database (Denmark)

    Sørensen, A.H.; Ahring, B.K.

    1997-01-01

    An enzyme-linked immunosorbent assay was developed for the detection of whole cells of methanogens in samples from anaerobic continuously stirred tank digesters treating slurries of solid waste. The assay was found to allow for quantitative analysis of the most important groups of methanogens...... in samples from anaerobic digesters in a reproducible manner. Polyclonal antisera against eight strains of methanogens were employed in the test, The specificities of the antisera were increased by adsorption with cross-reacting cells. The reproducibility of the assay depended on the use of high......-quality microtiter plates and the addition of dilute hydrochloric acid to the samples. In an experiment on different digester samples, the test demonstrated a unique pattern of different methanogenic strains present in each sample. The limited preparatory work required for the assay and the simple assay design make...

  5. The development of an Enzyme Linked Immunosorbent Assay for detecting Injectious laryngotrachitis viral antibodies in chicken serum

    Directory of Open Access Journals (Sweden)

    Risa Indriani

    2002-06-01

    Full Text Available The aim of this study was to develop an Enzyme-linked immunosorbent assay (ELISA for detection of antibody against gallid herpes virus, the causal agent of infectious laryngotracheitis (ILT in chicken. Its application in experimental chicken under laboratory condition was also evaluated. Results showed that ELISA for ILT was developed successfully with sensitivity and specificity was 98% and 97,14% respectively. The ELISA was able to determine the dynamic of antibodies respond in experimental chickens following vaccination and artificial infection with ILT virus. It was concluded that this ELISA offers a simple, sensitive and specific antibody assay for detection of antibodies against ILT virus in chickens arising from vaccination or infection.

  6. An enzyme-linked immunosorbent assay (ELISA) for quantification of mouse surfactant protein D (SP-D)

    DEFF Research Database (Denmark)

    Hansen, Søren; Schmidt, Vivi; Steffensen, Maria Abildgaard

    2008-01-01

    innate immune cells, such as macrophages and neutrophils. It also modulates the adaptive immune response by interacting with antigen-presenting cells and T cells. Monoclonal anti-mouse-SP-D antibodies were raised from SP-D deficient mice using recombinant SP-D as antigen. Ten monoclonal antibodies were......Surfactant protein D (SP-D) is a pattern recognition molecule of the collectin family of C-type lectins. It is found in the airways and at mucosal surfaces. SP-D is part of the innate immune system where it neutralizes and leads to elimination of microorganisms. It regulates the functions of other...... characterized and validated for use in sandwich enzyme-linked immunosorbent assay (ELISA). Based on two of these, we established an ELISA that allows for measurements of mouse SP-D in various body fluids. The final ELISA was optimized and calibrated with a standard of purified recombinant mouse SP-D, which...

  7. Sandwich enzyme-linked immunosorbent assay for the quantification of human serum albumin fragment 408-423 in bodily fluids.

    Science.gov (United States)

    Mohr, Katharina B; Zirafi, Onofrio; Hennies, Mark; Wiese, Sebastian; Kirchhoff, Frank; Münch, Jan

    2015-05-01

    Urinary levels of human serum albumin (hSA) fragment 408-423 have been proposed to represent an early marker for graft-versus-host disease (GvHD) and chronic kidney diseases. Here, we developed an enzyme-linked immunosorbent assay (ELISA) for the quantification of hSA(408-423). The sandwich ELISA has a detection limit of 0.5ng/ml and is highly specific for hSA(408-423) because it does not cross-react with other albumin fragments or the full-length precursor. This ELISA allows rapid and convenient quantification of hSA(408-423) in bodily fluids, further clarifying the prognostic and diagnostic value of this peptide in GvHD, kidney disease, and other disorders. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Evaluation of the dot enzyme-linked immunosorbent assay in comparison with standard ELISA for the immunodiagnosis of human toxocariasis

    Directory of Open Access Journals (Sweden)

    Roldán William

    2006-01-01

    Full Text Available A dot enzyme-linked immunosorbent assay (dot-ELISA was standardized using excretory-secretory antigens of Toxocara canis for the rapid immunodiagnosis of human toxocariasis. Thirty patients with clinical signs of toxocariasis, 20 cases with other parasitic diseases, and 40 healthy subjects were tested. A total of 0.2 ng of antigen per dot, serum dilution of 1:160 and dilution conjugate of 1:1000 were found optimal. The sensitivity and specificity of the assay were 100 and 95%, respectively. Comparable sensitivity of dot-ELISA and the standard ELISA was obtained, but only 3 cross-reactions occurred in the dot-ELISA, compared with 6 in the standard ELISA. Dot-ELISA is simple to perform, rapid, and low cost. Large-scale screening studies should be done to evaluate its usefulness under field conditions.

  9. Rapid Enzyme-Linked Immunosorbent Assay for the Detection of Hantavirus-Specific Antibodies in Divergent Small Mammals

    Directory of Open Access Journals (Sweden)

    Karla Cautivo

    2014-05-01

    Full Text Available We assessed the utility of an enzyme-linked immunosorbent assay (ELISA for the detection of hantavirus-specific antibodies from sera of Oligoryzomys longicaudatus, the principal reservoir of Andes virus (ANDV, using an antigen previously developed for detection of antibodies to Sin Nombre virus (SNV in sera from Peromyscus maniculatus. The assay uses a protein A/G horseradish peroxidase conjugate and can be performed in as little as 1.5 hours. Serum samples from Oligoryzomys longicaudatus collected in central-south Chile were used and the assay identified several that were antibody positive. This assay can be used for the rapid detection of antibodies to divergent hantaviruses from geographically and phylogenetically distant rodent species.

  10. Evaluation of a covalent mix-enzyme linked immunosorbent assay for screening of Salmonella antibodies in pig serum

    DEFF Research Database (Denmark)

    Chow, E.Y.W.; Wu, J.T.Y.; Jauho, E.S.

    2004-01-01

    in 5 laboratories from Europe and North America. Comparison with culture results showed that 88.5% of 26 culture-positive animals were ELISA positive, as were 55% of 60 animals from 2 culture-positive pig herds. Of 90 animals from 2 high health farms with no clinical symptoms of salmonellosis, 98......In this study, a commercial Salmonella covalent mix-enzyme linked immunosorbent assay (ELISA) for serological detection of Salmonella infection in swine was evaluated by comparing it with the conventional fecal culture method and inter-laboratory proficiency testing, using a panel of sera tested.......9% tested negative. The interlaboratory comparison study found a kappa value of 0.9 between our laboratory (using an automated system) and the manufacturer laboratory (using the manual method). Comparison of ELISA results from all 5 participating laboratories showed very good to excellent agreement, between...

  11. Recombinant Plasmodium falciparum glutamate rich protein; purification and use in enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Dziegiel, Morten Hanefeld; Borre, M B; Jepsen, S

    1991-01-01

    New Guinea (MAD20) and Honduras (HB3) completely absorbed specific antibodies, indicating the presence of conserved epitopes produced by all isolates of P. falciparum. Recombinant GLURP489-1271 ELISA is sensitive and rapid, and therefore well-suited for sero-epidemiological studies, and for control...... GLURP489-1271 was expressed as a chimeric protein, fused with E. coli beta-galactosidase. However, antibodies in sera were directed only against the malaria part of the fusion protein and not against beta-galactosidase. Antigen from in vitro P. falciparum cultures of isolates from Tanzania (F32), Papua...

  12. Use of Polymerase Chain Reaction Enzyme Linked Oligonucleotide Sorbent Assay (Pcr-Elosa for Detection of Disease Agents

    Directory of Open Access Journals (Sweden)

    Simson Tarigan

    2016-03-01

    Full Text Available Diagnostic tool comprises one of the vital components in the control of infectious diseases. One of the most common techniques in the diagnosis of infectious disease currently available is the polymerase chain reaction (PCR because this technique is very sensitive, specific, and rapid. This technique requires an adjunct technique to indicate the formation of the right reaction product. Agarose gel electrophoresis has been the most common technique to visualise the PCR product or amplicon. Enzyme linked oligonucleotide sorbent assay (ELOSA is an alternative technique which is more sensitive and gives more important identity of the amplicon. This technique can be more than 100 times as sensitive as a gel agarose electrophoresis, and very specific since confirmation of the amplicon is carried out by DNA hibridisation. The capacity of the ELOSA can also be extended to the detection of disease-causal agent at subtype level, or detection of mutation at particular location in a gene. Since the equipment used for ELOSA is similar to that for ELISA (enzyme linked immunosorbent assay, a large number of samples can be accomplished rapidly. As in ELISA, a number of variation can be made in ELOSA depend on the requirement. Nucleotide can be immobilised on the microwell plate either by passive adsorbtion, by first conjugation of nucleotide with biotin then immobilisation on streptavidin-coated microwell plate, or immobilisaion by covalent bonding. The PCR and ELOSA can be performed at separate or in a single tube by first immobilising the PCR primers on the surface of microwell plates.

  13. The analysis of directions for improvement of competitiveness in domestic hotel enterprises: Students attitudes

    OpenAIRE

    Đorđević Dejan; Bogetić Srđan; Ćoćkalo Dragan; Lekić Nemanja

    2016-01-01

    Global market changes are forcing modern hotel enterprises to adjust their business in order to survive on the market by satisfying their end users. Serbian hotel enterprises have, in a certain extent, accepted new market trends. However, the biggest problems seem to be poor traffic infrastructure and the introduction of the ISO management standards which are necessary conditions for increasing competitiveness level of domestic hotel enterprises. Modern hotel industry cannot be imagined nowad...

  14. Forces that direct the competition in the electric power industry in the new institutional scenery

    International Nuclear Information System (INIS)

    Ribeiro Filho, Ary Pinto; Moraes, Walter Fernando Araujo de

    1999-01-01

    This work identifies the probable strategic characteristics of the interconnected North-Northeast Brazilian electricity industry, after the current restructuring and privatization process has been implemented. It is a 15.0 thousand MW generation industry supplying more than 33.5 million consumers. The normative scenery for analysis of the electricity industry takes into consideration the premises that the government establishes the vertical separation of generation, transmission, distribution and retailing, and introduces the regulation to a competitive industrial structure in generation and retailing. It is assumed that free access to transmit and distribute electricity and broad choices for consumers are the main features for competition in both generation and retailing. The essence of formulating strategy is to relate a company with its environment, considering the industrial structure. Porter's five forces model for industry environment and competition, emphasizing the role of the government in such regulated industry, is the basic theoretical reference. The main strategic characteristics related to entry barriers, rivalry intensity, supplier power, customer power and substitute products are analyzed. (author)

  15. An enzyme-linked immunosorbent assay (ELISA) for methylphenidate (Ritalin ) in urine.

    Science.gov (United States)

    Lewis, Mark G; Lewis, John G; Elder, Peter A; Moore, Grant A

    2003-09-01

    A direct enyzme-linked immunosorbent assay (ELISA) for urinary immunoreactive methylphenidate (Ritalin), in which a standard 96-well microtiter plate is used, is described. For this ELISA, a methylphenidate-thyroglobulin conjugate is immobilized to the microtiter plate and competes with methylphenidate in the standard or urine sample for antibody-binding sites. After washing, the sheep methylphenidate antibody bound to immobilized methylphenidate is detected with peroxidase-labelled goat antisheep IgG. Following a further wash, tetramethylbenzidine is added, color is developed, and the plate is read at 450 nm on an ELISA plate reader. This method is unaffected by drugs of abuse and is suitable for routine use in the toxicology laboratory.

  16. Simulation of competitive grain growth upon the directional solidification of a Ni-base superalloy

    Science.gov (United States)

    Pozdniakov, A. N.; Monastyrskiy, V. P.; Ershov, M. Yu.; Monastyrskiy, A. V.

    2015-01-01

    Using the numerical simulation in the CA-FE module of the ProCAST simulation program, a systematic investigation of competitive growth of grains in a thin plate has been performed over a wide range of values of the temperature gradient and solidification rate. It has been established that the result of the simulation in the case of converging grains depends on the only parameter, i.e., the ratio of the value of the overgrowth of the grain with the preferred orientation to the size of the cell of the computational grid. Thus, the size of the cell is an important adjusting parameter of the model and must be coordinated with the parameters of the dendritic structure under given growth conditions. The grain with the preferred orientation always displaces neighboring diverging grains. The converging grains are eliminated if their deviation from the vector of the temperature gradient exceeds 20°. At the smaller angles of deviation, the result of the competitive growth depends on the size of the computational cell and varies from their joint growth (at the cell size of 5 μm) to the displacement of grains with the preferred orientation (at the cell size of 20 μm). However, all of the results of the simulation agree with the experimental data available in the literature. For the efficient selection of grains with the preferred orientation, regimes with a low temperature gradient and high growth rate are favorable.

  17. Optimal generation and reserve dispatch in a multi-area competitive market using a hybrid direct search method

    International Nuclear Information System (INIS)

    Chun Lung Chen

    2005-01-01

    With restructuring of the power industry, competitive bidding for energy and ancillary services are increasingly recognized as an important part of electricity markets. It is desirable to optimize not only the generator's bid prices for energy and for providing minimized ancillary services but also the transmission congestion costs. In this paper, a hybrid approach of combining sequential dispatch with a direct search method is developed to deal with the multi-product and multi-area electricity market dispatch problem. The hybrid direct search method (HDSM) incorporates sequential dispatch into the direct search method to facilitate economic sharing of generation and reserve across areas and to minimize the total market cost in a multi-area competitive electricity market. The effects of tie line congestion and area spinning reserve requirement are also consistently reflected in the marginal price in each area. Numerical experiments are included to understand the various constraints in the market cost analysis and to provide valuable information for market participants in a pool oriented electricity market. (author)

  18. Optimal generation and reserve dispatch in a multi-area competitive market using a hybrid direct search method

    International Nuclear Information System (INIS)

    Chen, C.-L.

    2005-01-01

    With restructuring of the power industry, competitive bidding for energy and ancillary services are increasingly recognized as an important part of electricity markets. It is desirable to optimize not only the generator's bid prices for energy and for providing minimized ancillary services but also the transmission congestion costs. In this paper, a hybrid approach of combining sequential dispatch with a direct search method is developed to deal with the multi-product and multi-area electricity market dispatch problem. The hybrid direct search method (HDSM) incorporates sequential dispatch into the direct search method to facilitate economic sharing of generation and reserve across areas and to minimize the total market cost in a multi-area competitive electricity market. The effects of tie line congestion and area spinning reserve requirement are also consistently reflected in the marginal price in each area. Numerical experiments are included to understand the various constraints in the market cost analysis and to provide valuable information for market participants in a pool oriented electricity market

  19. The analysis of directions for improvement of competitiveness in domestic hotel enterprises: Students attitudes

    Directory of Open Access Journals (Sweden)

    Đorđević Dejan

    2016-01-01

    Full Text Available Global market changes are forcing modern hotel enterprises to adjust their business in order to survive on the market by satisfying their end users. Serbian hotel enterprises have, in a certain extent, accepted new market trends. However, the biggest problems seem to be poor traffic infrastructure and the introduction of the ISO management standards which are necessary conditions for increasing competitiveness level of domestic hotel enterprises. Modern hotel industry cannot be imagined nowadays without big international hotel chains and the emergence of new market niches aimed at young customers born between 1980 and 2000, the so-called millennia's, who represent the largest group of smart phone users. Beside these obvious challenges that Serbian hotel industry has to face there is also a good potential in the field of congress tourism which has become very popular in the world in recent years.

  20. enzyme-linked

    African Journals Online (AJOL)

    Material and methods. Isolation of HBsAg . HBsAg was prepared from donated blood heavily: contami- nated with hepatitis B virus. Typically, HBsAg in I litre ofserum was precipitated by addition of PEG 6000 (11% w/v) and the precipitate recovered by centrifugation at I 000g for 10 minutes. The precipitate was redissolved in ...

  1. Volume 10 No. 9 September 2010 3065 A COMPETITIVE ENZYME ...

    African Journals Online (AJOL)

    user

    2010-09-09

    Sep 9, 2010 ... A competitive enzyme-linked immunosorbent assay (cELISA) for determination of diminazene residues in edible animal tissues after extraction in 0.1 M borax pH 9.7 is described. The assay has advantages of speed, high throughput and lower cost of analysis compared to the other conventional methods.

  2. Improved quantification of a commercial enzyme-linked immunosorbent assay kit for measuring anti-MDA5 antibody.

    Science.gov (United States)

    Gono, Takahisa; Okazaki, Yuka; Murakami, Akihiro; Kuwana, Masataka

    2018-04-09

    To compare the quantitative performance for measuring anti-MDA5 antibody titer of two enzyme-linked immunosorbent assay (ELISA) systems: an in-house ELISA and the commercial MESACUP TM anti-MDA5 test. Anti-MDA5 antibody titer was measured in sera from 70 patients with dermatomyositis using an in-house ELISA and the MESACUP TM anti-MDA5 test side-by-side. For the commercial ELISA kit, serum samples diluted 1:101 were used according to the manufacturer's protocol, but serial dilutions of sera were also examined to identify the optimal serum dilution for quantification. The anti-MDA5 antibody titers measured by the in-house and commercial ELISAs were positively correlated with each other (r = 0.53, p = .0001), but the antibody titer measured by the commercial ELISA was less sensitive to change after medical treatment, and 37 (80%) of 46 anti-MDA5-positive sera had antibody titer exceeding the quantification range specified by the manufacturer (≥150 index). Experiments using diluted serum samples revealed that diluting the sera 1:5050 improved the quantitative performance of the MESACUP TM anti-MDA5 test, including a better correlation with the in-house ELISA results and an increased sensitivity to change. We improved the ability of the commercial ELISA kit to quantify anti-MDA5 antibody titer by altering its protocol.

  3. Development of a quantitative sandwich enzyme-linked immunosorbent assay for detecting the MPT64 antigen of Mycobacterium tuberculosis.

    Science.gov (United States)

    Ji, Mijung; Cho, Byungki; Cho, Young Shik; Park, Song-Yong; Cho, Sang-Nae; Jeon, Bo-Young; Yoon, Byoung-Su

    2014-05-01

    Tuberculosis (TB) is a major infectious disease and is responsible for two million deaths annually. For the identification and quantitation of Mycobacterium tuberculosis (M. tuberculosis), a causative agent of TB, a sandwich enzyme-linked immunosorbent assay (ELISA) against the MPT64 protein of M. tuberculosis, an antigen marker of the M. tuberculosis complex, was developed. The MPT64 protein was expressed, and anti-MPT64 monoclonal antibodies were prepared. A sandwich ELISA was established using recombinant MPT64 protein and anti-MPT64 monoclonal antibodies. The sandwich MPT64 ELISA was evaluated using reference and clinical mycobacterial strains. The sandwich MPT64 ELISA detected MPT64 protein from 2.1 ng/mL to 250 ng/mL (equivalent to 1.7×10⁴ CFU/mL and 2.0×10⁶ CFU/mL). All 389 clinical M. tuberculosis isolates tested positive in the sandwich MPT64 ELISA (sensitivity, 100%), and the assay showed no cross reactivity to any tested nontuberculous mycobacterial strain (specificity, 100%). The sandwich MPT64 ELISA is a highly sensitive and quantitative test for MPT64 protein, which can identify M. tuberculosis.

  4. An enzyme-linked immunosorbent assay for the epidemiological survey of Dermatophilus congolensis infection in camels (Camelus dromedarius).

    Science.gov (United States)

    Gitao, C G

    1993-06-01

    The breeding of camels (Camelus dromedarius) is especially important in arid and semi-arid areas of Africa, where drought and famine frequently occur. A number of diseases which impair camel production have recently been described, including dermatophilosis (caused by Dermatophilus congolensis). However, it is not possible to determine the prevalence of infection from clinical cases alone. An enzyme-linked immunosorbent assay has therefore been developed to determine the epidemiological prevalence of D. congolensis infection in sera of camels. Whole-cell antigen was used on microplates and the test serum was added. Horseradish peroxidase-conjugated sheep antibodies against heavy and light chains of camel immunoglobulin (Ig)G were then added, followed by substrate. The test was used to trace the antibody profile of twelve experimentally-infected camels. Peak antibody levels in serum occurred within twenty-one days following infection. It is planned to use this test to determine the epidemiological prevalence of D. congolensis infection in camels reared in a pastoral area of Kenya.

  5. Analytical characterization and clinical evaluation of an enzyme-linked immunosorbent assay for measurement of afamin in human plasma.

    Science.gov (United States)

    Dieplinger, Benjamin; Egger, Margot; Gabriel, Christian; Poelz, Werner; Morandell, Elisabeth; Seeber, Beata; Kronenberg, Florian; Haltmayer, Meinhard; Mueller, Thomas; Dieplinger, Hans

    2013-10-21

    Comparative proteomics has recently identified afamin, the newest member of the albumin gene family, as a potential biomarker for ovarian cancer. The aim of this study was the analytical and clinical evaluation of a sandwich enzyme-linked immunosorbent assay for the determination of afamin in human plasma. We evaluated precision, linearity, and detection limit of the assay, analyte stability and biological variability, determined reference values and quantified afamin concentrations in various diseases. Within-run and total coefficients of variation were heart failure. Patients with pneumonia or sepsis exhibited markedly decreased afamin plasma concentrations. However, patients with chronic renal disease or chronic obstructive pulmonary disease showed no difference in afamin plasma concentrations as compared to healthy individuals. Correlation analyses revealed an inverse association between afamin and inflammatory biomarkers. The afamin assay meets quality specifications for laboratory medicine. The results of the clinical assay evaluation revealed novel insights with respect to afamin as a potential negative acute phase protein and should encourage further studies. © 2013.

  6. Screening of Dengue virus antiviral activity of marine seaweeds by an in situ enzyme-linked immunosorbent assay.

    Directory of Open Access Journals (Sweden)

    Andrea Cristine Koishi

    Full Text Available Dengue is a significant public health problem worldwide. Despite the important social and clinical impact, there is no vaccine or specific antiviral therapy for prevention and treatment of dengue virus (DENV infection. Considering the above, drug discovery research for dengue is of utmost importance; in addition natural marine products provide diverse and novel chemical structures with potent biological activities that must be evaluated. In this study we propose a target-free approach for dengue drug discovery based on a novel, rapid, and economic in situ enzyme-linked immunosorbent assay and the screening of a panel of marine seaweed extracts. The in situ ELISA was standardized and validated for Huh7.5 cell line infected with all four serotypes of DENV, among them clinical isolates and a laboratory strain. Statistical analysis showed an average S/B of 7.2 and Z-factor of 0.62, demonstrating assay consistency and reliability. A panel of fifteen seaweed extracts was then screened at the maximum non-toxic dose previously determined by the MTT and Neutral Red cytotoxic assays. Eight seaweed extracts were able to reduce DENV infection of at least one serotype tested. Four extracts (Phaeophyta: Canistrocarpus cervicornis, Padina gymnospora; Rhodophyta: Palisada perforate; Chlorophyta: Caulerpa racemosa were chosen for further evaluation, and time of addition studies point that they might act at an early stage of the viral infection cycle, such as binding or internalization.

  7. Use of hydrophilic extra-viral domain of canine distemper virus H protein for enzyme-linked immunosorbent assay development.

    Science.gov (United States)

    Cho, Ki-hyun; Kim, Jeongmi; Yoo, Hyun-ah; Kim, Dae-hee; Park, Seung-yong; Song, Chang-seon; Choi, In-soo; Lee, Joong-bok

    2014-12-01

    Simple methods for measuring the levels of serum antibody against canine distemper virus (CDV) would assist in the effective vaccination of dogs. To develop an enzyme-linked immunosorbent assay (ELISA) specific for CDV, we expressed hydrophilic extra-viral domain (HEVD) protein of the A75/17-CDV H gene in a pET 28a plasmid-based Escherichia (E.) coli vector system. Expression was confirmed by dot and Western blotting. We proposed that detection of E. coli-expressed H protein might be conformation- dependent because intensities of the reactions observed with these two methods varied. The H gene HEVD protein was further purified and used as an antigen for an ELISA. Samples from dogs with undetectable to high anti-CDV antibody titers were analyzed using this HEVD-specific ELISA and a commercial CDV antibody detection kit (ImmunoComb). Levels of HEVD antigenicity measured with the assays and immunochromatography correlated. These data indicated that the HEDV protein may be used as antigen to develop techniques for detecting antibodies against CDV.

  8. ENZYME-LINKED IMMUNOSORBENT ASSAY FOR SCREENING DIOXIN SOIL CONTAMINATION BY UNCONTROLLED COMBUSTION DURING INFORMAL RECYCLING IN SLUMS

    Science.gov (United States)

    Trindade, Mirta; Nording, Malin; Nichkova, Mikaela; Spinnel, Erik; Haglund, Peter; Last, Michael S.; Gee, Shirley; Hammock, Bruce; Last, Jerold A.; González-Sapienza, Gualberto; Brena, Beatriz M.

    2010-01-01

    Uncontrolled combustion due to garbage recycling is a widespread activity among slum dwellers in distressed economy countries and has been indicated as a major source of dioxin contamination. However, because of the high cost and complexity of gas chromatography/high-resolution mass spectrometry (GC-HRMS) analysis, the magnitude of the problem remains largely unknown. The present study describes a first approach toward the use of a dioxin antibody-based enzyme-linked immunosorbent assay (ELISA) as the basis for a sustainable, simple, and low-cost monitoring program to assess the toxicological impact of uncontrolled combustion in slums. A panel of 16 samples was analyzed by GC-HRMS and ELISA on split extracts. Close to 20% of the analyzed samples showed dioxin concentrations up to almost twice the guidance level for residential soil in several countries, pointing out the need for performing a large-scale monitoring program. Despite the potential for variations in dioxin congener distribution due to the mixed nature of the incinerated material, there was a good correlation between the toxic equivalents as determined by GC-HRMS and ELISA. Furthermore, an interlaboratory ELISA validation showed that the capacity to perform the dioxin ELISA was successfully transferred between laboratories. It was concluded that the ELISA method performed very well as a screening tool to prioritize samples for instrumental analysis, which allows cutting down costs significantly. PMID:18522475

  9. Development and validation of an enzyme-linked immunosorbent assay for antibodies against Mycobacterium bovis in european wild boar

    Directory of Open Access Journals (Sweden)

    Gortázar Christian

    2008-11-01

    Full Text Available Abstract Background Bovine tuberculosis (bTB remains a significant problem in some parts of Spain largely because of contacts between cattle and wildlife reservoirs in extensive grazing systems. European Wild boar (Sus scrofa is one of the species involved in the transmission of the disease to other species. Fast and simple detection methods would be critical for assessing infection prevalence, study the mechanisms of pathogen transmission and monitoring the effects of TB control measures. Results An enzyme-linked immunosorbent assay (ELISA to detect antibodies against Mycobacterium bovis in wild boar serum was developed and validated on 185 sera from TB positive and negative wild boar. Based on antigen inoculation of captive animals as well as tuberculosis compatible lesions, culture results and molecular analysis of hunted individuals, animals were allocated into two groups: tuberculosis positive group and tuberculosis negative group. After optimization of the positive to negative ratio using different combinations of serum dilutions and conjugate concentrations, the test yielded a sensitivity of 72.60% and a specificity of 96.43% for the best cut-off. Conclusion Although some negative group animals showed an ELISA positive reaction (

  10. Enzyme-linked immunosorbent assay of relaxin-like gonad-stimulating peptide in the starfish Patiria (Asterina) pectinifera.

    Science.gov (United States)

    Mita, Masatoshi; Katayama, Hidekazu

    2018-03-01

    A relaxin-like gonad-stimulating peptide (RGP) from starfish Patiria (Asterina) pectinifera is the first identified invertebrate gonadotropin for final gamete maturation. Recently, we succeeded in obtaining specific antibodies against P. pectinifera RGP (PpeRGP). In this study, the antibodies were used for the development of a specific and sensitive enzyme-linked immunosorbent assay (ELISA) for the measurement of PpeRGP. A biotin-conjugated peptide that binds to peroxidase-conjugated streptavidin is specifically detectable using 3,3',5,5'-tetramethylbenzidine (TMB)/hydrogen peroxide as a substrate; therefore, biotin-conjugated RGP (biotin-PpeRGP) was synthesized chemically. Similarly to PpeRGP, synthetic biotin-PpeRGP bound to the antibody against PpeRGP. In binding experiments with biotin-PpeRGP using wells coated with the antibody, a displacement curve was obtained using serial concentrations of PpeRGP. The ELISA system showed that PpeRGP could be measured in the range 0.01-10pmol per 50µl assay buffer. On the contrary, the B-chains of PpeRGP, Asterias amurensis RGP, Aphelasterias japonica RGP, and human relaxin showed minimal cross-reactivity in the ELISA, except that the A-chain of PpeRGP affected it slightly. These results strongly suggest that this ELISA system is highly specific and sensitive with respect to PpeRGP. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. An enzyme-linked immunosorbent assay and a gold-nanoparticle based immuno chromatographic test for amatoxins using recombinant antibody

    International Nuclear Information System (INIS)

    He, Kuo; Zhao, Ruiping; Wang, Lixia; Feng, Tingting; Wei, Dong; Zhang, Xiuyuan

    2016-01-01

    The authors describe two kinds of rapid assays for the determination of amatoxins in mushrooms. The first is an enzyme-linked immunosorbent assay (ELISA) using horseradish peroxidase. The second is a rapid immuno chromatographic assay that uses colloidal gold as a red label (CG-ICA). Both are based on the use of a well-characterized recombinant single chain variable fragment antibody (named scFv-A4). The half-maximum inhibition concentrations (IC50) of α-amanitin, β-amanitin and γ-amanitin are 78, 85 and 90 ng⋅mL -1 , and the limits of detection (LODs; for IC15) are 1.9, 2.1 and 2.8 ng⋅mL -1 . The method was applied to the determination of amanitins in mushrooms, and the LODs for α-amanitin, β-amanitin and γ-amanitin in mushroom samples were found to be 4.9, 6.4 and 8.3 ng⋅mL -1 . The visual minimum detection limits of the optimized CGIA are 4 and 6 ng⋅mL -1 for mushroom samples. The test can be performed within 10 min. The results of the analysis of spiked samples showed that the CG-IA can rapidly and semi-quantitatively quantify amatoxins in mushroom samples on site and at low costs. (author)

  12. Screening of Dengue Virus Antiviral Activity of Marine Seaweeds by an In Situ Enzyme-Linked Immunosorbent Assay

    Science.gov (United States)

    Koishi, Andrea Cristine; Zanello, Paula Rodrigues; Bianco, Éverson Miguel; Bordignon, Juliano; Nunes Duarte dos Santos, Claudia

    2012-01-01

    Dengue is a significant public health problem worldwide. Despite the important social and clinical impact, there is no vaccine or specific antiviral therapy for prevention and treatment of dengue virus (DENV) infection. Considering the above, drug discovery research for dengue is of utmost importance; in addition natural marine products provide diverse and novel chemical structures with potent biological activities that must be evaluated. In this study we propose a target-free approach for dengue drug discovery based on a novel, rapid, and economic in situ enzyme-linked immunosorbent assay and the screening of a panel of marine seaweed extracts. The in situ ELISA was standardized and validated for Huh7.5 cell line infected with all four serotypes of DENV, among them clinical isolates and a laboratory strain. Statistical analysis showed an average S/B of 7.2 and Z-factor of 0.62, demonstrating assay consistency and reliability. A panel of fifteen seaweed extracts was then screened at the maximum non-toxic dose previously determined by the MTT and Neutral Red cytotoxic assays. Eight seaweed extracts were able to reduce DENV infection of at least one serotype tested. Four extracts (Phaeophyta: Canistrocarpus cervicornis, Padina gymnospora; Rhodophyta: Palisada perforate; Chlorophyta: Caulerpa racemosa) were chosen for further evaluation, and time of addition studies point that they might act at an early stage of the viral infection cycle, such as binding or internalization. PMID:23227238

  13. Dual-color plasmonic enzyme-linked immunosorbent assay based on enzyme-mediated etching of Au nanoparticles

    Science.gov (United States)

    Guo, Longhua; Xu, Shaohua; Ma, Xiaoming; Qiu, Bin; Lin, Zhenyu; Chen, Guonan

    2016-09-01

    Colorimetric enzyme-linked immunosorbent assay utilizing 3‧-3-5‧-5-tetramethylbenzidine(TMB) as the chromogenic substrate has been widely used in the hospital for the detection of all kinds of disease biomarkers. Herein, we demonstrate a strategy to change this single-color display into dual-color responses to improve the accuracy of visual inspection. Our investigation firstly reveals that oxidation state of 3‧-3-5‧-5-tetramethylbenzidine (TMB2+) can quantitatively etch gold nanoparticles. Therefore, the incorporation of gold nanoparticles into a commercial TMB-based ELISA kit could generate dual-color responses: the solution color varied gradually from wine red (absorption peak located at ~530 nm) to colorless, and then from colorless to yellow (absorption peak located at ~450 nm) with the increase amount of targets. These dual-color responses effectively improved the sensitivity as well as the accuracy of visual inspection. For example, the proposed dual-color plasmonic ELISA is demonstrated for the detection of prostate-specific antigen (PSA) in human serum with a visual limit of detection (LOD) as low as 0.0093 ng/mL.

  14. Improved Canine and Human Visceral Leishmaniasis Immunodiagnosis Using Combinations of Synthetic Peptides in Enzyme-Linked Immunosorbent Assay

    Science.gov (United States)

    Costa, Míriam Maria; Penido, Marcos; dos Santos, Mariana Silva; Doro, Daniel; de Freitas, Eloísa; Michalick, Marilene Susan Marques; Grimaldi, Gabriel; Gazzinelli, Ricardo Tostes; Fernandes, Ana Paula

    2012-01-01

    Background Zoonotic visceral leishmaniasis (VL) is a severe infectious disease caused by protozoan parasites of the genus Leishmania and the domestic dogs are the main urban parasite reservoir hosts. In Brazil, indirect fluorescence antibody tests (IFAT) and indirect enzyme linked immunosorbent assay (ELISA) using promastigote extracts are widely used in epidemiological surveys. However, their sensitivity and specificity have often been compromised by the use of complex mixtures of antigens, which reduces their accuracy allowing the maintenance of infected animals that favors transmission to humans. In this context, the use of combinations of defined peptides appears favorable. Therefore, they were tested by combinations of five peptides derived from the previously described Leishmania diagnostic antigens A2, NH, LACK and K39. Methodology/Principal Findings Combinations of peptides derived A2, NH, LACK and K39 antigens were used in ELISA with sera from 44 human patients and 106 dogs. Improved sensitivities and specificities, close to 100%, were obtained for both sera of patients and dogs. Moreover, high sensitivity and specificity were observed even for canine sera presenting low IFAT anti-Leishmania antibody titers or from asymptomatic animals. Conclusions/Significance The use of combinations of B cell predicted synthetic peptides derived from antigens A2, NH, LACK and K39 may provide an alternative for improved sensitivities and specificities for immunodiagnostic assays of VL. PMID:22629475

  15. Evaluation of an enzyme linked immunosorbent assay kit for the detection of Babesia bovis antibodies in cattle in Argentina

    International Nuclear Information System (INIS)

    Echaide, S.; Echaide, I.E.; Mangold, A.J.; Lugaresi, C.I.; Guglielmone, A.A.; Gaido, A.B.

    1998-01-01

    An enzyme linked immunosorbent assay (ELISA) for the detection of antibodies to Babesia bovis was evaluated by using sera of 874 cattle carrying B. bovis antibodies, 700 sera of uninfected cattle, and 357 sera from calves from 16 herds subjected to different B. bovis inoculation rates. The seropositive/ seronegative cut-off point set as double the mean percent positivity of negative cattle sera (= 16%). The sensitivity of the ELISA (four trials) ranged from 97.1% to 100% and the specificity (three trials) varied from 92.0% to 97.0%. The agreement between ELISA and immunofluorescent antibody test was ≥ 90.0% in 18 of 23 evaluations and it ranged from 86.0% to 88.0% in the remainder. The correlation coefficient between percentage of sera positive to ELISA and IFA test in 16 herds was 0.9958 (P<0.001). The ELISA has the advantages of a high sensitivity, objectivity and capacity to test large number of samples in short period of time and could replace the IFA test specially for epidemiological studies. (author)

  16. Establishment of a miniaturized enzyme-linked immunosorbent assay for human transferrin quantification using an intelligent multifunctional analytical plate.

    Science.gov (United States)

    Spies, Peter; Chen, Guo Jun; Gygax, Daniel

    2008-11-01

    A miniaturized enzyme-linked immunosorbent assay (ELISA) with a reaction volume of 5 microl for human transferrin quantification has successfully been developed using an intelligent multifunctional analytical plate (IMAPlate 5RC96), the first miniature analytical platform capable of manually performing parallel liquid transfer, reaction, and analysis. This is the first article to validate the platform for the ELISA application. The data obtained from the standards in this miniaturized ELISA can well be fitted by a one-site binding reaction mode, the coefficient of variation (CV) of the whole plate for an artificial sample (spiking a known concentration of human transferrin into the assay diluent) is 7.0%, and the mean recovery is between 94 and 114% (n=96), comparable to the values from conventional ELISA in a 96-well format plate. The IMAPlate 5RC96-based miniaturized ELISA not only can reduce sample and reagent consumption to 5% of the conventional ELISA but also can shorten the reaction time. Combined with the advantages brought by miniaturization, the easy-to-handle, parallel, and simultaneous liquid transfer features of the IMAPlate 5RC96 provide a completely new lab tool for manually performing high-throughput ELISA. Our results demonstrate that the IMAPlate 5RC96 is a convenient, robust, high-throughput lab device feasible for miniaturized ELISA in an ordinary laboratory.

  17. Recombinase polymerase and enzyme-linked immunosorbent assay as a DNA amplification-detection strategy for food analysis.

    Science.gov (United States)

    Santiago-Felipe, S; Tortajada-Genaro, L A; Puchades, R; Maquieira, A

    2014-02-06

    Polymerase chain reaction in conjunction with enzyme-linked immunosorbent assay (PCR-ELISA) is a well-established technique that provides a suitable rapid, sensitive, and selective method for a broad range of applications. However, the need for precise rapid temperature cycling of PCR is an important drawback that can be overcome by employing isothermal amplification reactions such as recombinase polymerase amplification (RPA). The RPA-ELISA combination is proposed for amplification at a low, constant temperature (40°C) in a short time (40 min), for the hybridisation of labelled products to specific 5'-biotinylated probes/streptavidin in coated microtiter plates at room temperature, and for detection by colorimetric immunoassay. RPA-ELISA was applied to screen common safety threats in foodstuffs, such as allergens (hazelnut, peanut, soybean, tomato, and maize), genetically modified organisms (P35S and TNOS), pathogenic bacteria (Salmonella sp. and Cronobacter sp.), and fungi (Fusarium sp.). Satisfactory sensitivity and reproducibility results were achieved for all the targets. The RPA-ELISA technique does away with thermocycling and provides a suitable sensitive, specific, and cost-effective method for routine applications, and proves particularly useful for resource-limited settings. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Detection by radioimmunoassay and enzyme-linked immunosorbent assay of coronavirus antibodies in bovine serum and lacteal secretions.

    Science.gov (United States)

    Rodak, L; Babiuk, L A; Acres, S D

    1982-07-01

    The sensitivity of a radioimmunoassay (RIA), an enzyme-linked immunosorbent assay (ELISA), and a serum neutralization assay (SN) for detecting antibodies to bovine coronavirus in serum and colostrum were compared. Although there proved to be a good correlation among all three assays (r = 0.915 and 0.964 for RIA with SN and ELISA, respectively), RIA and ELISA proved to be at least 10 times more sensitive than neutralization tests. By using these techniques, it was possible to detect a time-dependent decrease in antibody levels in bovine colostrum after parturition. Using ELISA, we demonstrated that 12 of 12 herds in Saskatchewan, and 109 of 110 animals tested, and antibody to bovine coronavirus. There was no elevated antibody response in serum or lacteal secretions of cows vaccinated once or twice with a commercially available modified live rota-coronavirus vaccine. In addition to being more sensitive than SN, ELISA and RIA proved to have other advantages for measuring antibody levels to bovine coronavirus and therefore warrant wider use as tools in diagnostic virology.

  19. Field assessment of the enzyme linked immunosorbent assay for foot-and-mouth disease virus diagnosis and typing

    International Nuclear Information System (INIS)

    Smitsaart, E.; Fondevila, N.; Compaired, D.; Maradei, E.; Fernandez, E.

    1998-01-01

    The objective of the present study was to evaluate the enzyme linked immunosorbent assay (ELISA) in comparison with the complement fixation test (CFT) for the diagnosis and typing of foot-and-mouth disease (FMD) virus (FMDV). Diagnostic material was epithelium from either suspected cases of FMD or from animals experimentally infected with FMDV. Epithelial suspensions and supernatant fluids from cell culture passage were assayed by CFT and ELISA. The superiority of the ELISA over the CFT was demonstrated: 1) the detection rate was 23% higher than that of CFT on original (epithelial) suspensions (OS) submissions of all sample (positive and negative) and 30% higher on supernatant fluids from cell culture passage, 2) the detection rate of ELISA on OS of confirmed positive samples was 28% higher than that of CFT, 3) no significant differences were observed in the detection and typing rates between the PANAFTOSA and FAO/IAEA ELISA kits (P<0.05) and 4) the sensitivity of the ELISA was 16 to 85 times higher than that of CFT when serial dilutions of sample homogenates were examined. (author)

  20. Validation of an improved enzyme-linked immunosorbent assay for the diagnosis of trypanosomal antibodies in Ghanaian cattle

    International Nuclear Information System (INIS)

    Doku, C.K.; Seidu, I.B.M.

    2000-01-01

    The validation of an enzyme-linked immunosorbent assay (Ab-ELISA) for the detection of antibodies to pathogenic trypanosomes in cattle is described. Two hundred known negative sera obtained from the tsetse-free zone of Dori (Burkina Faso) were analyzed using microtitre plates pre-coated with crude antigen lysates of Trypanosoma congolense and T. vivax. A pre-test optimization was carried out and a percent positivity (PP) of 50% was chosen (specificity: >82%) for assaying field sera. A total of 440 serum samples collected from cattle in areas of known and unknown disease prevalence were assayed. For all animals the packed red cell volume (PCV) was determined and the buffy coat technique (BCT) and blood smears were examined to detect trypanosomes at the species level. A comparison of the BCT and Ab-ELISA results showed there was a much higher prevalence of antibodies to both species than the parasite prevalence as shown by the BCT (10 fold). The rate of agreement between BCT-positive and Ab-ELISA-positive samples for both species was low (<10%). No conclusion could be drawn from this finding because of the low number of known BCT positive cases that were identified. There was a better, albeit highly variable, agreement between BCT-negative and Ab-ELISA-negative samples (30-70%). Proposals for further improvement of the Ab-ELISA and prospects for the use of the assay in the monitoring of trypanosomosis control in Ghana are discussed. (author)

  1. Development of an indirect enzyme-linked immunosorbent assay for the detection of leptospiral antibodies in dogs.

    Science.gov (United States)

    Ribotta, M J; Higgins, R; Gottschalk, M; Lallier, R

    2000-01-01

    Serology plays an important role in the diagnosis of leptospirosis. Few laboratories have the resources, expertise, or facilities to perform the microscopic agglutination test (MAT). Thus, there is a need for a rapid and simple serological test that could be used in any diagnostic laboratory. In this study, a genus-specific, heat-stable antigenic preparation from Leptospira interrogans serovar pomona was used in an enzyme-linked immunosorbent assay (ELISA) for the detection of leptospiral antibodies in dog sera. This antigenic preparation reacted with rabbit antisera against L. interrogans serovars bratislava, autumnalis, icterohaemorrhagiae and pomona and with rabbit antiserum against L. kirschneri serovar grippotyphosa. The ELISA showed a relative specificity of 95.6% with 158 dog sera which were negative at a dilution of 1:100 in the MAT for serovars pomona, bratislava, icterohaemorrhagiae, autumnalis, hardjo, and grippotyphosa. The relative sensitivity of this assay with 21 dog sera that revealed serovars MAT titres of > or =100 to different serovars was 100%. This assay is easily standardized, technically more advantageous than MAT, and uses an antigenic preparation that can be routinely prepared in large amounts. It was concluded that this ELISA is sufficiently sensitive test to be used as an initial screening test for the detection of leptospiral antibodies in canine sera, with subsequent confirmation of positive test results with the MAT.

  2. Comparison of agar gel immunodiffusion test, enzyme-linked immunosorbent assay and PCR in diagnostics of enzootic bovine leukosis

    Directory of Open Access Journals (Sweden)

    Malovrh Tadej

    2005-01-01

    Full Text Available Bovine leukaemia virus (BLV is a retrovirus that induces a chronic infection in cattle. Once infected, cattle remain virus carriers for life and start to show an antibody response within a few weeks after infection. Eradication and control of the disease are based on early diagnostics and segregation of the carriers. The choice of a diagnostic method depends on the eradication programme, money resources and characteristics of the herd to be analysed. The agar gel immunodiffusion (AGID test has been the serological test of choice for routine diagnosis of serum samples. Nevertheless, in more recent years, the enzyme-linked immunosorbent assay (ELISA has replaced the AGID for large scale testing. For this purpose, commercially available BLV-ELISA kits were compared to the AGID and to the polymerase chain reaction (PCR method performed with two sets of primers, amplifying env region. The ELISA kit based on the p24 core protein was found to be less specific and served as a screening test. The ELISA kit based on the envelope glycoprotein (gpSI served as a verification test and gave a good correlation with the AGID test and PCR method. However, ELISA showed a higher sensitivity than AGID. The p24 based ELiSA was useful for screening a large number of samples, whereas gp51 based ELISA, AGID and PCR were more important for detecting the antibody response against the individual BLV-proteins and therefore for verification of the infection with BLV.

  3. Comparison of Laboratory-Developed and Commercial Monoclonal Antibody-Based Sandwich Enzyme-Linked Immunosorbent Assays for Almond (Prunus dulcis) Detection and Quantification.

    Science.gov (United States)

    Liu, Changqi; Chhabra, Guneet S; Zhao, Jing; Zaffran, Valerie D; Gupta, Sahil; Roux, Kenneth H; Gradziel, Thomas M; Sathe, Shridhar K

    2017-10-01

    A commercially available monoclonal antibody (mAb)-based direct sandwich enzyme-linked immunosorbent assay (ELISA) kit (BioFront Technologies, Tallahassee, Fla., U.S.A.) was compared with an in-house developed mAb 4C10-based ELISA for almond detection. The assays were comparable in sensitivity (limit of detection < 1 ppm full fat almond, limit of quantification < 5 ppm full fat almond), specificity (no cross-reactivity with 156 tested foods at a concentration of 100000 ppm whole sample), and reproducibility (intra- and interassay variability < 15% CV). The target antigens were stable and detectable in whole almond seeds subjected to autoclaving, blanching, frying, microwaving, and dry roasting. The almond recovery ranges for spiked food matrices were 84.3% to 124.6% for 4C10 ELISA and 81.2% to 127.4% for MonoTrace ELISA. The almond recovery ranges for commercial and laboratory prepared foods with declared/known almond amount were 30.9% to 161.2% for 4C10 ELISA and 38.1% to 207.6% for MonoTrace ELISA. Neither assay registered any false-positive or negative results among the tested commercial and laboratory prepared samples. Ability to detect and quantify trace amounts of almonds is important for improving safety of almond sensitive consumers. Two monoclonal antibody-based ELISAs were compared for almond detection. The information is useful to food industry, regulatory agencies, scientific community, and almond consumers. © 2017 Institute of Food Technologists®.

  4. Management of bacterial kidney disease in Chinook Salmon hatcheries based on broodstock testing by enzyme-linked immunosorbent assay: A multiyear study

    Science.gov (United States)

    Munson, A. Douglas; Elliott, Diane G.; Johnson, Keith

    2010-01-01

    From the mid-1980s through the early 1990s, outbreaks of bacterial kidney disease (BKD) caused by Renibacterium salmoninarum continued in Chinook salmon Oncorhynchus tshawytscha in Idaho Department of Fish and Game (IDFG) hatcheries despite the use of three control methods: (1) injection of returning adult fish with erythromycin to reduce prespawning BKD mortality and limit vertical transmission of R. salmoninarum, (2) topical disinfection of green eggs with iodophor, and (3) prophylactic treatments of juvenile fish with erythromycin-medicated feed. In addition, programs to manage BKD through measurement of R. salmoninarum antigen levels in kidney tissues from spawning female Chinook salmon by an enzyme-linked immunosorbent assay (ELISA) were tested over 13–15 brood years at three IDFG hatcheries. The ELISA results were used for either (1) segregated rearing of progeny from females with high ELISA optical density (OD) values (usually ≥0.25), which are indicative of high R. salmoninarum antigen levels, or (2) culling of eggs from females with high ELISA OD values. The ELISA-based culling program had the most profound positive effects on the study populations. Mortality of juvenile fish during rearing was significantly lower at each hatchery for brood years derived from culling compared with brood years for which culling was not practiced. The prevalence of R. salmoninarum in juvenile fish, as evidenced by detection of the bacterium in kidney smears by the direct fluorescent antibody test, also decreased significantly at each hatchery. In addition, the proportions of returning adult females with kidney ELISA OD values of 0.25 or more decreased 56–85% for fish reared in brood years during which culling was practiced, whereas the proportions of ELISA-negative adults increased 55–58%. This management strategy may allow IDFG Chinook salmon hatcheries to reduce or eliminate prophylactic erythromycin-medicated feed treatments. We recommend using ELISA

  5. Detection of serum antimüllerian hormone in women approaching menopause using sensitive antimüllerian hormone enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Robertson, David M; Kumar, Ajay; Kalra, Bhanu; Shah, Shivani; Pruysers, Enid; Vanden Brink, Heidi; Chizen, Donna; Visser, Jenny A; Themmen, Axel P; Baerwald, Angela

    2014-12-01

    Current antimüllerian hormone (AMH) immunoassays are insufficiently sensitive to detect circulating AMH levels in ovulatory women approaching menopause. The aim of this study was to detect serum AMH levels across the menstrual cycle with age, using two new AMH enzyme-linked immunosorbent assay (ELISA) kits with increased sensitivity and differing specificity. Serum AMH levels were determined every 2 to 3 days across the interovulatory interval of menstrual cycles among women of early-mid reproductive age (18-35 y; n = 10) and late reproductive age (45-55 y; n = 17). Two highly sensitive AMH ELISAs (designated 24/32 and 24/37) with differing sensitivities were developed and applied to sera using a recombinant human pro-mature AMH preparation as reference. A third AMH ELISA (Gen II AMH ELISA kit; Beckman Coulter, Brea, CA) used was directed on mature-pro regions of AMH. AMH levels in all cycles were detectable with the 24/32 and 24/37 AMH ELISAs. AMH levels across the menstrual cycle were highly correlated (r = 0.98) between the 24/32 and 24/37 AMH ELISAs and the Gen II AMH ELISA (r = 0.94), but with large intracycle variations observed in older women. In late reproductive age, more than 95% of AMH values were detectable with the 24/32 and 24/37 AMH ELISAs, whereas only 36% of AMH values were detectable with the Gen II AMH ELISA. AMH levels were detected in cycles with lower antral follicle count and at a later age using the 24/32 and 24/37 AMH ELISAs compared with the Gen II AMH ELISA. AMH level correlated with antral follicle count in younger women, but not in older women. The new 24/32 and 24/37 AMH ELISAs have the sensitivity to monitor ovarian follicle profiles in late reproductive age.

  6. Performance Assessment and Comparability of a Commercial Enzyme-Linked Immunosorbent Assay Kit with Liquid Chromatography-Tandem Mass Spectrometry for Chloramphenicol Residues in Crab and Shrimp.

    Science.gov (United States)

    Jester, Edward L E; Loader, Jared I; El Said, Kathleen R; Abraham, Ann; Flores Quintana, Harold A; Plakas, Steven M

    2016-01-01

    Monitoring for chloramphenicol (CAP) in aquaculture products is primarily performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), which requires expensive equipment and specialized training. Many laboratories prefer to screen samples with facile and high-throughput enzyme-linked immunosorbent assay (ELISA) kits for CAP residues before submitting samples for LC-MS/MS quantification and confirmation. We evaluated the performance of a Ridascreen (R-Biopharm) ELISA kit for CAP in spiked and incurred crab and shrimp muscle at levels bracketing the minimum required performance level for analysis (0.3 ng/g). The Ridascreen ELISA kit incorporates antibody directed against CAP. Incurred CAP levels in crab and shrimp muscle were verified using LC-MS/MS. We found good repeatability (relative standard deviation) of the ELISA in spiked and incurred crab and shrimp muscle samples, with values ranging from 6.8 to 21.7%. Recoveries of CAP from tissues spiked at 0.15 to 0.60 ng/g ranged from 102 to 107%. Minimal cross-reactivity with blank crab and shrimp muscle matrix components was observed. ELISA data were highly correlated with those of LC-MS/MS for CAP in incurred muscle tissue. We believe this study to be the first evaluation of the performance and comparability of a CAP ELISA kit and LC-MS/MS for determination of CAP residues, as well as their elimination, in crab muscle. Our findings support the use of this ELISA kit for screening purposes and, when used in conjunction with validated instrumental methods, for regulatory monitoring of CAP in these species.

  7. Application of enzyme-linked immunosorbent assay for measurement of polychlorinated biphenyls from hydrophobic solutions: Extracts of fish and dialysates of semipermeable membrane devices: Chapter 26

    Science.gov (United States)

    Zajicek, James L.; Tillitt, Donald E.; Huckins, James N.; Petty, Jimmie D.; Potts, Michael E.; Nardone, David A.

    1996-01-01

    Determination of PCBs in biological tissue extracts by enzyme-linked immunosorbent assays (ELISAs) can be problematic, since the hydrophobic solvents used for their extraction and isolation from interfering biochemicals have limited compatibility with the polar solvents (e.g. methanol/water) and the immunochemical reagents used in ELISA. Our studies of these solvent effects indicate that significant errors can occur when microliter volumes of PCB containing extracts, in hydrophobic solvents, are diluted directly into methanol/water diluents. Errors include low recovery and excess variability among sub-samples taken from the same sample dilution. These errors are associated with inhomogeneity of the dilution, which is readily visualized by the use of a hydrophobic dye, Solvent Blue 35. Solvent Blue 35 is also used to visualize the evaporative removal of hydrophobic solvent and the dissolution of the resulting PCB/dye residue by pure methanol and 50% (v/v) methanol/water, typical ELISA diluents. Evaporative removal of isooctane by an ambient temperature nitrogen purge with subsequent dissolution in 100% methanol gives near quantitative recovery of model PCB congeners. We also compare concentrations of total PCBs from ELISA (ePCB) to their corresponding concentrations determined from capillary gas chromatography (GC) in selected fish sample extracts and dialysates of semipermeable membrane device (SPMD) passive samplers using an optimized solvent exchange procedure. Based on Aroclor 1254 calibrations, ePCBs (ng/mL) determined in fish extracts are positively correlated with total PCB concentrations (ng/mL) determined by GC: ePCB = 1.16 * total-cPCB - 5.92. Measured ePCBs (ng/3 SPMDs) were also positively correlated (r2 = 0.999) with PCB totals (ng/3 SPMDs) measured by GC for dialysates of SPMDs: ePCB = 1.52 * total PCB - 212. Therefore, this ELISA system for PCBs can be a rapid alternative to traditional GC analyses for determination of PCBs in extracts of biota or in

  8. Onderzoek naar toepasbaarheid van Enzyme-Linked Immunosorbent Assay (ELISA) voor het bepalen van aflatoxinen in voedings- en voedermiddelen 1e interimrapport: Orientatie en taakstelling

    NARCIS (Netherlands)

    Egmond; H.P. van; Paulsch; W.E.; Sizoo; E.A.

    1987-01-01

    Immunochemische methoden van onderzoek voor het bepalen van mycotoxinen komen langzamerhand in de belangstelling te staan, vooral Enzyme-Linked Immunosorbent Assay (ELISA). Om een beeld te krijgen van de praktische en wetenschappelijke karakteristieken van ELISA's in het

  9. Evaluation of an enzyme-linked immunosorbent assay for serological surveillance of infection with Actinobacillus pleuropneumoniae serotype 5 in pig herds

    DEFF Research Database (Denmark)

    Klausen, Joan; Andresen, Lars Ole; Barfod, Kristen

    2002-01-01

    An indirect enzyme-linked immunoassay for serological surveillance of infection of pigs with Actinobacillus pleuropneumoniae (Ap) serotype 5 was developed. The antigen used was prepared from Ap serotype 5b strain L20. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis...

  10. Enzyme-Linked Immunosorbent Assay To Differentiate the Antibody Responses of Animals Infected with Brucella Species from Those of Animals Infected with Yersinia enterocolitica O9

    OpenAIRE

    Erdenebaatar, Janchivdorj; Bayarsaikhan, Balgan; Watarai, Masahisa; Makino, Sou-ichi; Shirahata, Toshikazu

    2003-01-01

    Enzyme-linked immunosorbent assays using antigens extracted from Brucella abortus with n-lauroylsarcosine differentiated natural Brucella-infected animals from Brucella-vaccinated or Yersinia enterocolitica O9-infected animals. A field trial in Mongolia showed cattle, sheep, goat, reindeer, camel, and human sera without infection could be distinguished from Brucella-infected animals by conventional serological tests.

  11. Comparison of an enzyme linked immunosorbent assay (ELISA) and a radioallergosorbent test (RAST) for detection of IgE antibodies to Brugia malayi

    NARCIS (Netherlands)

    Wahyuni, Sitti; van Ree, Ronald; Mangali, Andarias; Supali, Taniawati; Yazdanbakhsh, Maria; Sartono, Erliyani

    2003-01-01

    The enzyme linked immunosorbent assay (ELISA) for specific IgE antibodies to Brugia malayi was compared with the radioallergosorbent test (RAST) for use in immunoepidemiological studies of lymphatic filariasis. Sera used were from individuals (aged 5-82 years) living in an area endemic for lymphatic

  12. SERO-DIAGNOSIS OF TUBERCULOSIS WITH A60 ANTIGEN ENZYME-LINKED-IMMUNOSORBENT-ASSAY - FAILURE IN HIV-INFECTED INDIVIDUALS IN GHANA

    NARCIS (Netherlands)

    VANDERWERF, TS; DAS, PK; VANSOOLINGEN, D; YONG, S; VANDERMARK, TW

    In order to assess the diagnostic usefulness of the A60 (ANDA Biologicals, Strassbourg, France) sero-diagnostic enzyme-linked immunosorbent assay (ELISA) kit for tuberculosis in Africa, sera of 53 pulmonary smear-positive tuberculosis (TB) patients, 30 apparently healthy control subjects and 6 AIDS

  13. Simultaneous determination of 13 fluoroquinolone and 22 sulfonamide residues in milk by a dual-colorimetric enzyme-linked immunosorbent assay

    Science.gov (United States)

    Enzyme-linked immunosorbent assays (ELISAs) usually focus on the detection of a single analyte or a single group of analytes, e.g., fluoroquinolones or sulfonamides. However, it is often necessary to simultaneously monitor the two classes of antimicrobial residues in different food matrices. In th...

  14. The use of enzyme-linked immunosorbent assay systems for the serology and antigen detection in parvovirus, coronavirus and rotavirus infections in dogs in The Netherlands.

    NARCIS (Netherlands)

    G.F. Rimmelzwaan (Guus); J. Groen (Jan); H.F. Egberink (Herman); G.H.A. Borst (Gerrit); F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Albert)

    1991-01-01

    textabstractComplex trapping blocking (CTB) enzyme-linked immunosorbent assays (ELISAs) and indirect ELISAs for the detection of antibodies to canine parvovirus (CPV), canine coronavirus (CCV) and rotavirus in sera of dogs were established. Double antibody sandwich ELISAs for the detection of CPV-,

  15. Use of rapid dipstick and latex agglutination tests and enzyme-linked immunosorbent assay for serodiagnosis of Amebic liver abscess, amebic colitis, and Entamoeba histolytica cyst passage

    NARCIS (Netherlands)

    van Doorn, H. Rogier; Hofwegen, Henk; Koelewijn, Rob; Gilis, Henk; Peek, Ron; Wetsteyn, Jose C. F. M.; van Genderen, Perry J. J.; Vervoort, Tony; van Gool, Tom

    2005-01-01

    A homemade enzyme-linked immunosorbent assay (ELISA) and a dipstick assay (Dipstick) for the detection of anti-Entamoeba histolytica antibodies in serum were developed and evaluated together with a commercially available latex agglutination test (LAT; Laboratoires Fumouze) for their use in

  16. Forum: Interaction of State Aid, Free Movement, Policy Competition and Abuse Control in Direct Tax Matters

    NARCIS (Netherlands)

    Wattel, P.J.

    2013-01-01

    The European Union has woken up to State aid possibly contained in national direct tax measures. As a result, the number of Commission actions against Member States on the basis of fiscal State aid has increased in recent years, with some amazing results. It has also revealed overlap and

  17. Comparison of enzyme-linked immunosorbent assay test with immunoblot assay in the diagnosis of pemphigus in Indian patients

    Directory of Open Access Journals (Sweden)

    Khandpur Sujay

    2010-01-01

    Full Text Available Background: The diagnosis of pemphigus vulgaris (PV and pemphigus foliaceous (PF rests upon clinical, histological and immunofluorescence features. Enzyme-linked immunosorbent assay (ELISA test and immunoblot (IB assay have shown variable sensitivity and specificity. Aims: We compared the utility of ELISA and IB in pemphigus patients. Methods: Sixty-six pemphigus cases (PV-54, PF-12 and 72 controls (other vesicobullous disorders and healthy controls were inducted. ELISA for anti-Dsg 3 and 1 antibodies and IB assay were performed. Results: On ELISA, both mean anti-Dsg 1 and 3 titers were raised in PV and PF. Mean anti-Dsg 1 in mucocutaneous PV was significantly higher than in mucosal PV and mean anti-Dsg 3 was significantly raised in PV than in PF. Anti-Dsg 1 and 3 in the control group were negative. Sensitivity and specificity of ELISA in PV was 98.14% and 90.5% while in PF it was 91.6% and 61.1%, respectively.On IB in PV, 36 cases (66.67% showed the 130 kDa and 160 kDa antigen bands, 12 (22.2% only the 130 kDa and six (11.1% only the 160 kDa band. Eight of the nine pure mucosal cases (88.8% showed only the 130 kDa. In PF, only the 160 kDa antigen was detected. These antigens were not identified in the control group. Sensitivity and specificity of IB in PV was 88.9% and 100% and in PF it was 100% and 95.2%, respectively. Conclusion: Both tests could differentiate pemphigus from other dermatoses, including other blistering disorders. ELISA could not make a distinction between PV and PF or between the various clinical phenotypes of PV. IB differentiated between PV and PF and the different clinical variants of PV.

  18. Caffeic and chlorogenic acids inhibit key enzymes linked to type 2 diabetes (in vitro): a comparative study.

    Science.gov (United States)

    Oboh, Ganiyu; Agunloye, Odunayo M; Adefegha, Stephen A; Akinyemi, Ayodele J; Ademiluyi, Adedayo O

    2015-03-01

    Chlorogenic acid is a major phenolic compound that forms a substantial part of plant foods and is an ester of caffeic acid and quinic acid. However, the effect of the structures of both chlorogenic and caffeic acids on their antioxidant and antidiabetic potentials have not been fully understood. Thus, this study sought to investigate and compare the interaction of caffeic acid and chlorogenic acid with α-amylase and α-glucosidase (key enzymes linked to type 2 diabetes) activities in vitro. The inhibitory effect of the phenolic acids on α-amylase and α-glucosidase activities was evaluated. Thereafter, their antioxidant activities as typified by their 1,1-diphenyl-2 picrylhydrazyl radical scavenging ability and ferric reducing antioxidant properties were determined. The results revealed that both phenolic acids inhibited α-amylase and α-glucosidase activities in a dose-dependent manner (2-8 μg/mL). However, caffeic acid had a significantly (pchlorogenic acid (α-amylase IC50=9.10 μg/mL and α-glucosidase IC50=9.24 μg/mL). Furthermore, both phenolic acids exhibited high antioxidant properties, with caffeic acid showing higher effects. The esterification of caffeic acid with quinic acid, producing chlorogenic acid, reduces their ability to inhibit α-amylase and α-glucosidase activities. Thus, the inhibition of α-amylase and α-glucosidase activities by the phenolic acids could be part of the possible mechanism by which the phenolic acids exert their antidiabetic effects.

  19. Recombinase polymerase and enzyme-linked immunosorbent assay as a DNA amplification-detection strategy for food analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santiago-Felipe, S.; Tortajada-Genaro, L.A.; Puchades, R.; Maquieira, A., E-mail: amaquieira@qim.upv.es

    2014-02-06

    Graphical abstract: -- Highlights: •Recombinase polymerase amplification is a powerful DNA method operating at 40 °C. •The combination RPA–ELISA gives excellent performances for high-throughput analysis. •Screening of food safety threats has been done using standard laboratory equipment. •Allergens, GMOs, bacteria, and fungi have been successfully determined. -- Abstract: Polymerase chain reaction in conjunction with enzyme-linked immunosorbent assay (PCR–ELISA) is a well-established technique that provides a suitable rapid, sensitive, and selective method for a broad range of applications. However, the need for precise rapid temperature cycling of PCR is an important drawback that can be overcome by employing isothermal amplification reactions such as recombinase polymerase amplification (RPA). The RPA–ELISA combination is proposed for amplification at a low, constant temperature (40 °C) in a short time (40 min), for the hybridisation of labelled products to specific 5′-biotinylated probes/streptavidin in coated microtiter plates at room temperature, and for detection by colorimetric immunoassay. RPA–ELISA was applied to screen common safety threats in foodstuffs, such as allergens (hazelnut, peanut, soybean, tomato, and maize), genetically modified organisms (P35S and TNOS), pathogenic bacteria (Salmonella sp. and Cronobacter sp.), and fungi (Fusarium sp.). Satisfactory sensitivity and reproducibility results were achieved for all the targets. The RPA–ELISA technique does away with thermocycling and provides a suitable sensitive, specific, and cost-effective method for routine applications, and proves particularly useful for resource-limited settings.

  20. Detection of immunoglobulin M and G antibodies against cytomegalovirus early and late antigens by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Middeldorp, J M; Jongsma, J; ter Haar, A; Schirm, J; The, T H

    1984-10-01

    A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) is described for the detection of immunoglobulin M and antibodies with specifity for human cytomegalovirus (CMV) early (CMV-EA) and late (CMV-LA) antigens. The emphasis is on the production of high-quality CMV antigens, CMV-EA and CMV-LA separately, and conditions for their application in the ELISA. The induction of CMV-EA and -LA in infected cell extracts was studied in detail by using human sera with defined antibody specificity for CMV-EA and CMV-LA. This resulted in the development of a simple whole cell extraction procedure that provided a high yield of CMV antigens with reproducible antigen quality. The antigens were specific for the detection of anti-CMV antibodies. The influence of autoantibodies on the determination of CMV-specific antibodies was investigated. Parallel analysis of 322 human sera by indirect immunofluorescence and ELISA showed a high correlation between both assays (r = 0.9674 for CMV-EA and 0.9362 for CMV-LA). Antibody titers determined by ELISA were equal to (for CMV-EA) or slightly higher (for CMV-LA) that those determined by immunofluorescence but significantly higher (20- to 5,120-fold) than those determined by complement fixation. From 191 sera positive by ELISA (titer greater than or equal to 40) 4 (2.1%) were negative by immunofluorescence (titer less than 40), and from 61 ELISA-positive sera 12 (19.6%) were negative (titer less than 8) when tested by complement fixation. Consequently, ELISA for CMV may prove to be more reliable for the selection of CMV-seronegative blood donors than these other methods. The use of high-quality antigens allows more economic handling of large-scale serum determinations. Possibilities for further automation are discussed.

  1. Antibody Banding Patterns of the Enzyme-Linked Immunoelectrotransfer Blot and Brain Imaging Findings in Patients With Neurocysticercosis.

    Science.gov (United States)

    Arroyo, Gianfranco; Rodriguez, Silvia; Lescano, Andres G; Alroy, Karen A; Bustos, Javier A; Santivañez, Saul; Gonzales, Isidro; Saavedra, Herbert; Pretell, E Javier; Gonzalez, Armando E; Gilman, Robert H; Tsang, Victor C W; Garcia, Hector H

    2018-01-06

    The enzyme-linked immunoelectrotransfer blot (EITB) assay is the reference serological test for neurocysticercosis (NCC). A positive result on EITB does not always correlate with the presence of active infections in the central nervous system (CNS), and patients with a single viable brain cyst may be EITB negative. Nonetheless, EITB antibody banding patterns appears to be related with the expression of 3 protein families of Taenia solium, and in turn with the characteristics of NCC in the CNS (type, stage, and burden of viable cysts). We evaluated EITB antibody banding patterns and brain imaging findings of 548 NCC cases. Similar banding patterns were grouped into homogeneous classes using latent class analysis. The association between classes and brain imaging findings was assessed. Four classes were identified. Class 1 (patients negative or only positive to the GP50 band, related to the protein family of the same name) was associated with nonviable or single viable parenchymal cysticerci; class 2 (patients positive to bands GP42-39 and GP24, related to the T24-42 protein family, with or without anti-GP50 antibodies) was associated with intraparenchymal viable and nonviable infections; classes 3 and 4 (positive to GP50, GP42-39, and GP24 but also responding to low molecular weight bands GP21, GP18, GP14, and GP13, related to the 8 kDa protein family) were associated with extraparenchymal and intraparenchymal multiple viable cysticerci. EITB antibody banding patterns correlate with brain imaging findings and complement imaging information for the diagnosis of NCC and for staging NCC patients. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  2. Memory T-cell response to rotavirus detected with a gamma interferon enzyme-linked immunospot assay.

    Science.gov (United States)

    Kaufhold, Robin M; Field, Jodie A; Caulfield, Michael J; Wang, Su; Joseph, Heather; Wooters, Melissa A; Green, Tina; Clark, H Fred; Krah, David; Smith, Jeffrey G

    2005-05-01

    Measurements of serum-neutralizing antibody and anti-rotavirus immunoglobulin A (IgA) are the current standard for assessing immune responses following rotavirus vaccination. However, there is ongoing debate as to whether antibody titers correlate with protection against rotavirus gastroenteritis. Children recovering from rotavirus gastroenteritis have increased gamma interferon release from cultured peripheral blood mononuclear cells (PBMCs), suggesting that cell-mediated immunity (CMI) may play a role in viral clearance and protection from subsequent gastroenteritis. We have developed a gamma interferon enzyme-linked immunospot (ELISPOT) assay for evaluation of CMI responses to rotavirus using frozen PBMCs obtained from healthy adults. Responses to three different rotavirus antigen types were analyzed-a peptide pool based on the human VP6 sequence; reassortant human:bovine vaccine strains; and cell culture-adapted (CCA) human G1, G2, G3, G4, and bovine (WC3) G6 strains. The reassortant strains consist of a bovine WC3 genome background expressing the human rotavirus surface proteins VP7 (G1, G2, G3, or G4) or VP4 (P1). Responses to titrations of the peptide pool as well as CCA and reassortant strains were assessed. Gamma interferon ELISPOT responses were similar for CCA and reassortant strains, whether live or UV inactivated, and when tested either individually or pooled. For most subjects, responses to the VP6 peptide pool positively correlated with responses to CCA and reassortant strains. Cell depletion studies indicate the memory responses detected with these frozen adult PBMCs were primarily due to the CD4+ T-cell population. This gamma interferon ELISPOT assay provides a new tool to apply in clinical studies for the characterization of natural or vaccine-induced CMI to rotavirus.

  3. Recombinase polymerase and enzyme-linked immunosorbent assay as a DNA amplification-detection strategy for food analysis

    International Nuclear Information System (INIS)

    Santiago-Felipe, S.; Tortajada-Genaro, L.A.; Puchades, R.; Maquieira, A.

    2014-01-01

    Graphical abstract: -- Highlights: •Recombinase polymerase amplification is a powerful DNA method operating at 40 °C. •The combination RPA–ELISA gives excellent performances for high-throughput analysis. •Screening of food safety threats has been done using standard laboratory equipment. •Allergens, GMOs, bacteria, and fungi have been successfully determined. -- Abstract: Polymerase chain reaction in conjunction with enzyme-linked immunosorbent assay (PCR–ELISA) is a well-established technique that provides a suitable rapid, sensitive, and selective method for a broad range of applications. However, the need for precise rapid temperature cycling of PCR is an important drawback that can be overcome by employing isothermal amplification reactions such as recombinase polymerase amplification (RPA). The RPA–ELISA combination is proposed for amplification at a low, constant temperature (40 °C) in a short time (40 min), for the hybridisation of labelled products to specific 5′-biotinylated probes/streptavidin in coated microtiter plates at room temperature, and for detection by colorimetric immunoassay. RPA–ELISA was applied to screen common safety threats in foodstuffs, such as allergens (hazelnut, peanut, soybean, tomato, and maize), genetically modified organisms (P35S and TNOS), pathogenic bacteria (Salmonella sp. and Cronobacter sp.), and fungi (Fusarium sp.). Satisfactory sensitivity and reproducibility results were achieved for all the targets. The RPA–ELISA technique does away with thermocycling and provides a suitable sensitive, specific, and cost-effective method for routine applications, and proves particularly useful for resource-limited settings

  4. Comparison of Seven Commercial Antigen and Antibody Enzyme-Linked Immunosorbent Assays for Detection of Acute Dengue Infection

    Science.gov (United States)

    Jarman, Richard G.; Gibbons, Robert V.; Tanganuchitcharnchai, Ampai; Mammen, Mammen P.; Nisalak, Ananda; Kalayanarooj, Siripen; Bailey, Mark S.; Premaratna, Ranjan; de Silva, H. Janaka; Day, Nicholas P. J.; Lalloo, David G.

    2012-01-01

    Seven commercial assays were evaluated to determine their suitability for the diagnosis of acute dengue infection: (i) the Panbio dengue virus Pan-E NS1 early enzyme-linked immunosorbent assay (ELISA), second generation (Alere, Australia); (ii) the Panbio dengue virus IgM capture ELISA (Alere, Australia); (iii) the Panbio dengue virus IgG capture ELISA (Alere, Australia); (iv) the Standard Diagnostics dengue virus NS1 antigen ELISA (Standard Diagnostics, South Korea); (v) the Standard Diagnostics dengue virus IgM ELISA (Standard Diagnostics, South Korea); (vi) the Standard Diagnostics dengue virus IgG ELISA (Standard Diagnostics, South Korea); and (vii) the Platelia NS1 antigen ELISA (Bio-Rad, France). Samples from 239 Thai patients confirmed to be dengue virus positive and 98 Sri Lankan patients negative for dengue virus infection were tested. The sensitivities and specificities of the NS1 antigen ELISAs ranged from 45 to 57% and 93 to 100% and those of the IgM antibody ELISAs ranged from 85 to 89% and 88 to 100%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics ELISAs gave the best compromise between sensitivity and specificity (87 and 96%, respectively), as well as providing the best sensitivity for patients presenting at different times after fever onset. The Panbio IgG capture ELISA correctly classified 67% of secondary dengue infection cases. This study provides strong evidence of the value of combining dengue virus antigen- and antibody-based test results in the ELISA format for the diagnosis of acute dengue infection. PMID:22441389

  5. Postabsorptive hyperglucagonemia in patients with type 2 diabetes mellitus analyzed with a novel enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Matsuo, Toshihiro; Miyagawa, Jun-Ichiro; Kusunoki, Yoshiki; Miuchi, Masayuki; Ikawa, Takashi; Akagami, Takafumi; Tokuda, Masaru; Katsuno, Tomoyuki; Kushida, Akira; Inagaki, Takashi; Namba, Mitsuyoshi

    2016-05-01

    The aims of the present study were to investigate the performance of a novel sandwich enzyme-linked immunosorbent assay (ELISA) for measuring glucagon (1-29) with monoclonal antibodies against both the C- and N-terminal regions of glucagon (1-29), and to analyze the differences in plasma levels and responses of glucagon (1-29) to oral glucose loading in normal glucose tolerance (NGT) subjects and patients with type 2 diabetes mellitus. The cross-reactivity against proglucagon fragments using the ELISA kit and two types of conventional radioimmunoassay (RIA) kits was evaluated. A 75-g oral glucose tolerance test was carried out with NGT subjects and patients with type 2 diabetes mellitus, and the glucagon (1-29) concentration was measured using three types of kit. The ELISA kit clearly had the lowest cross-reactivity against miniglucagon (19-29) and glicentin (1-61). The oral glucose tolerance test was carried out with 30 NGT and 17 patients with type 2 diabetes mellitus. The glucagon (1-29) levels measured by the ELISA kit after glucose loading were significantly higher at all time-points in the type 2 diabetes mellitus group than in the NGT group. However, the glucagon (1-29) levels measured by one RIA kit were significantly higher in the NGT group, and those measured with the other RIA kit were approximately the same among the groups. The novel sandwich ELISA accurately determines plasma glucagon (1-29) concentrations with much less cross-reactivity against other proglucagon fragments than conventional RIA kits.

  6. Large-Scale Survey of Campylobacter Species in Human Gastroenteritis by PCR and PCR–Enzyme-Linked Immunosorbent Assay

    Science.gov (United States)

    Lawson, A. J.; Logan, J. M. J.; O'neill, G. L.; Desai, M.; Stanley, J.

    1999-01-01

    A PCR-based study of the incidence of enteropathogenic campylobacter infection in humans was done on the basis of a detection and identification algorithm consisting of screening PCRs and species identification by PCR-enzyme-linked immunosorbent assay. This was applied to DNA extracted from 3,738 fecal samples from patients with sporadic cases of acute gastroenteritis, submitted by seven regional Public Health Laboratories in England and Wales over a 2-year period. The sending laboratories had cultured “Campylobacter spp.” from 464 samples. The PCR methodologies detected 492 Campylobacter-positive samples, and the combination of culture and PCR yielded 543 Campylobacter-positive samples. There was identity (overlap) for 413 samples, but 79 PCR-positive samples were culture negative, and 51 culture-positive samples were PCR negative. While there was no statistically significant difference between PCR and culture in detection of C. jejuni-C. coli (PCR, 478 samples; culture, 461 samples), PCR provided unique data about mixed infections and non-C. jejuni and non- C. coli campylobacters. Mixed infections with C. jejuni and C. coli were found in 19 samples, and mixed infection with C. jejuni and C. upsaliensis was found in one sample; this was not apparent from culture. Eleven cases of gastroenteritis were attributed to C. upsaliensis by PCR, three cases were attributed to C. hyointestinalis, and one case was attributed to C. lari. This represents the highest incidence of C. hyointestinalis yet reported from human gastroenteritis, while the low incidence of C. lari suggests that it is less important in this context. PMID:10565897

  7. HPLC purification of recombinant NcGRA6 antigen improves enzyme-linked immunosorbent assay for serodiagnosis of bovine neosporosis.

    Science.gov (United States)

    Jenkins, M C; Fetterer, R; Schares, G; Björkman, C; Wapenaar, W; McAllister, M; Dubey, J P

    2005-08-10

    The gene for a dense granule protein (NcGRA6) of Neospora caninum was expressed in Escherichia coli as a His-tag fusion protein and purified by NiNTA affinity chromatography. In a preliminary study, high binding of antibodies from N. caninum-negative cows was observed in enzyme-linked immunosorbent assay (ELISA) using NiNTA-purified NcGRA6. Analysis of NiNTA eluates revealed a significant number of E. coli proteins that co-purified with recombinant NcGRA6. In an attempt to improve the relative sensitivity and specificity of the NcGRA6-based ELISA, the rNcGRA6 eluates were subjected to a secondary purification using reverse phase-high performance liquid chromatography (RP-HPLC). Analysis of RP-HPLC eluates by SDS-PAGE/silver staining revealed the purification of recombinant NcGRA6 from contaminating E. coli proteins. ELISAs using the RP-HPLC purified NcGRA6 (dELISA) or singly purified NcGRA6 (sELISA) for identifying seropositive and seronegative cows in a beef herd experiencing an epidemic outbreak of neosporosis were compared to standard assays based on native tachyzoite protein-immunofluorescence antibody test, immunoblot assay, and ISCOM-ELISA. The relative sensitivity, specificity, and kappa value of the NcGRA6d-ELISA were greatly improved over the NcGRA6s-ELISA when compared to the three native antigen immunoassays. These results indicate that removal of contaminating E. coli proteins improves the performance of recombinant NcGRA6 ELISA in diagnosing bovine neosporosis, and may have applicability to the use of recombinant proteins in diagnosing other infectious agents.

  8. Ultrasensitive direct competitive FLISA using highly luminescent quantum dot beads for tuning affinity of competing antigens to antibodies

    International Nuclear Information System (INIS)

    Xiong, Sicheng; Zhou, Yaofeng; Huang, Xiaolin; Yu, Ruijin; Lai, Weihua; Xiong, Yonghua

    2017-01-01

    Herein, for the first time we report a novel direct competitive fluorescence-linked immunosorbent assay (dcFLISA) for the ultrasensitive detection of ochratoxin A (OTA) by introducing a large size polymer beads loaded with quantum dots (QBs) as carrier of competing antigen for decreasing binding affinity to antibody and enhancing the fluorescent signal intensity. When using 255 nm QBs as carrier of competing antigen, the equilibrium dissociation constant of QB based competing antigen to antibodies can be tuned to 100 times higher than that of the horseradish peroxidase (HRP) based competing antigen by controlling labeled amounts of antigen on the surface of QBs. Various parameters that influenced the sensitivity of dcFLISA were investigated and optimized. Under optimum detection parameters, the dynamic linear range of developed dcFLISA for detecting OTA was established at 0.05 pg/mL to 1.56 pg/mL with a half maximal inhibitory concentration at 0.14 ± 0.04 pg/mL (n = 5), which is three orders of magnitude lower than that of conventional HRP-based dcELISA (0.24 ng/mL). The developed FLISA is also highly accurate, reliable, and shows no cross reaction to other mycotoxins. In summary, the proposed method offers a straightforward approach to improve the sensitivity of direct competitive immunoassay for trace small chemical molecule detection in food quality control, environmental monitoring, and clinical diagnosis. - Highlights: • Highly luminescent QBs were used as a carrier of competing antigen for ultrasensitive detection of OTA. • It is the first time to use a large size QBs as a carrier for tuning affinity of competing antigen to antibodies. • IC 50 value of QB-based dcFLISA is three orders of magnitude lower than that of HRP-based dcELISA.

  9. Framing Persoalan Indonesia Melalui Film Dokumenter Model Direct Cinema (Studi Pada Film-film Dokumenter Terbaik, Program Eagle Award Competitions Di Metro TV)

    OpenAIRE

    Styo Wibowo, Novin Farid

    2013-01-01

    FRAMING PERSOALAN INDONESIA MELALUI FILM DOKUMENTER MODELDIRECT CINEMA(STUDI PADA FILM-FILM DOKUMENTER TERBAIK, PROGRAM EAGLEAWARD COMPETITIONS DI METRO TV)Frames Indonesia Issues Through Direct Cinema DocumentaryFilm On Television (Framing Analysis of the 3 Best Documentary Film, Eagle AwardCompetitions Program at Metro TV)Novin Farid Styo WibowoJurusan Ilmu Komunikasi, Fakultas Ilmu Sosial dan Ilmu PolitikUniversitas Muhammadiyah MalangEmail : TThe research disc...

  10. Nonisotopic detection of human papillomavirus DNA in clinical specimens using a consensus PCR and a generic probe mix in an enzyme-linked immunosorbent assay format.

    Science.gov (United States)

    Kornegay, J R; Shepard, A P; Hankins, C; Franco, E; Lapointe, N; Richardson, H; Coutleé, F

    2001-10-01

    We assessed the value of a new digoxigenin (DIG)-labeled generic probe mix in a PCR-enzyme-linked immunosorbent assay format to screen for the presence of human papillomavirus (HPV) DNA amplified from clinical specimens. After screening with this new generic assay is performed, HPV DNA-positive samples can be directly genotyped using a reverse blotting method with product from the same PCR amplification. DNA from 287 genital specimens was amplified via PCR using biotin-labeled consensus primers directed to the L1 gene. HPV amplicons were captured on a streptavidin-coated microwell plate (MWP) and detected with a DIG-labeled HPV generic probe mix consisting of nested L1 fragments from types 11, 16, 18, and 51. Coamplification and detection of human DNA with biotinylated beta-globin primers served as a control for both sample adequacy and PCR amplification. All specimens were genotyped using a reverse line blot assay (13). Results for the generic assay using MWPs and a DIG-labeled HPV generic probe mix (DIG-MWP generic probe assay) were compared with results from a previous analysis using dot blots with a radiolabeled nested generic probe mix and type-specific probes for genotyping. The DIG-MWP generic probe assay resulted in high intralaboratory concordance in genotyping results (88% versus 73% agreement using traditional methods). There were 207 HPV-positive results using the DIG-MWP method and 196 positives using the radiolabeled generic probe technique, suggesting slightly improved sensitivity. Only one sample failed to test positive with the DIG-MWP generic probe assay in spite of a positive genotyping result. Concordance between the two laboratories was nearly 87%. Approximately 6% of samples that were positive or borderline when tested with the DIG-MWP generic probe assay were not detected with the HPV type-specific panel, perhaps representing very rare or novel HPV types. This new method is easier to perform than traditional generic probe techniques and uses

  11. Evaluation of three enzyme-linked immunosorbent assays for sarcoptic mange diagnosis and assessment in the Iberian ibex, Capra pyrenaica

    Directory of Open Access Journals (Sweden)

    Arián Ráez-Bravo

    2016-10-01

    Full Text Available Abstract Background Sarcoptic mange is a contagious skin disease caused by the mite Sarcoptes scabiei, affecting different mammalian species worldwide including the Iberian ibex (Capra pyrenaica, in which mortalities over 90 % of the population have been reported. No efficient diagnostic methods are available for this disease, particularly when there are low mite numbers and mild or no clinical signs. In this study, three enzyme-linked immunosorbent assays (ELISA developed for dog (ELISA A, Cantabrian chamois (Rupicapra pyrenaica parva (ELISA B and Alpine chamois (Rupicapra rupicapra (ELISA C, were evaluated to detect specific antibodies (IgG to sarcoptic mange in Iberian ibex sera. Methods Serum samples from 131 Iberian ibexes (86 healthy and 45 scabietic were collected from 2005 to 2012 in the Sierra Nevada Natural and National Parks (southern Spain. Based on visual inspection, ibexes were classified into one of three categories, namely healthy (without scabietic compatible lesions, mildly affected (skin lesions over less than 50 % of the body surface and severely affected (skin lesions over more than 50 % of the body surface. The optimal cut-off point, specificity, sensitivity and the area under the curve (AUC were calculated, and the agreement between tests was determined. Moreover, differences in the optical density (OD related to scabies severity have been evaluated for the best test. Results ELISA C showed better performance than the two other tests, reaching higher values of sensitivity (93.0 % and specificity (93.5 % against the visual estimation of the percentage of affected skin, chosen as the gold standard. Significantly higher concentrations of specific antibodies were observed with this test in the mildly and severely infested ibexes than in healthy ones. Conclusions Our results revealed that ELISA C was an optimal test to diagnose sarcoptic mange in the Iberian ibex. Further studies characterizing immune response during the

  12. Enzyme-linked immunosorbent assay characterization of basal variation and heritability of systemic microfibrillar-associated protein 4.

    Directory of Open Access Journals (Sweden)

    Susanne Gjørup Sækmose

    Full Text Available BACKGROUND: Microfibrillar-associated protein 4 (MFAP4 is a systemic biomarker that is significantly elevated in samples from patients suffering from hepatic cirrhosis. The protein is generally localized to elastic fibers and other connective tissue fibers in the extracellular matrix (ECM, and variation in systemic MFAP4 (sMFAP4 has the potential to reflect diverse diseases with increased ECM turnover. Here, we aimed to validate an enzyme-linked immunosorbent assay (ELISA for the measurement of sMFAP4 with an emphasis on the robustness of the assay. Moreover, we aimed to determine confounders influencing the basal sMFAP4 variability and the genetic contribution to the basal variation. METHODS: The sandwich ELISA was based on two monoclonal anti-MFAP4 antibodies and was optimized and calibrated with a standard of recombinant MFAP4. The importance of pre-analytical sample handling was evaluated regarding sample tube type, time, and temperature conditions. The mean value structure and variance structure was determined in a twin cohort including 1,417 Danish twins (age 18-67 years by mixed-effect linear regression modeling. RESULTS: The practical working range of the sandwich ELISA was estimated to be 4-75 U/ml. The maximum intra- and inter-assay variation was estimated to be 8.7% and 6.6%, respectively. Sample handling and processing appeared to influence MFAP4 measurements only marginally. The average concentration of sMFAP4 in the serum was 18.9 ± 8.4 (SD U/ml in the twin cohort (95% CI: 18.5-19.4, median sMFAP4 17.3 U/ml. The mean structure model was demonstrated to include waist-hip ratio, age, and cigarette smoking status in interactions with gender. A relatively low heritability of h(2 = 0.24 was found after applying a model including additive genetic factors and shared and non-shared environmental factors. CONCLUSIONS: The described ELISA provides robust measures of the liver fibrosis marker sMFAP4. The low heritability and the relatively

  13. High seroprevalence of Mycoplasma pneumoniae IgM in acute Q fever by enzyme-linked immunosorbent assay (ELISA.

    Directory of Open Access Journals (Sweden)

    Chung-Hsu Lai

    Full Text Available Q fever is serologically cross-reactive with other intracellular microorganisms. However, studies of the serological status of Mycoplasma pneumoniae and Chlamydophila pneumoniae during Q fever are rare. We conducted a retrospective serological study of M. pneumoniae and C. pneumoniae by enzyme-linked immunosorbent assay (ELISA, a method widely used in clinical practice, in 102 cases of acute Q fever, 39 cases of scrub typhus, and 14 cases of murine typhus. The seropositive (57.8%, 7.7%, and 0%, p<0.001 and seroconversion rates (50.6%, 8.8%, and 0%, p<0.001 of M. pneumoniae IgM, but not M. pneumoniae IgG and C. pneumoniae IgG/IgM, in acute Q fever were significantly higher than in scrub typhus and murine typhus. Another ELISA kit also revealed a high seropositivity (49.5% and seroconversion rate (33.3% of M. pneumoniae IgM in acute Q fever. The temporal and age distributions of patients with positive M. pneumoniae IgM were not typical of M. pneumoniae pneumonia. Comparing acute Q fever patients who were positive for M. pneumoniae IgM (59 cases with those who were negative (43 cases, the demographic characteristics and underlying diseases were not different. In addition, the clinical manifestations associated with atypical pneumonia, including headache (71.2% vs. 81.4%, p=0.255, sore throat (8.5% vs. 16.3%, p=0.351, cough (35.6% vs. 23.3%, p=0.199, and chest x-ray suggesting pneumonia (19.3% vs. 9.5%, p=0.258, were unchanged between the two groups. Clinicians should be aware of the high seroprevalence of M. pneumoniae IgM in acute Q fever, particularly with ELISA kits, which can lead to misdiagnosis, overestimations of the prevalence of M. pneumoniae pneumonia, and underestimations of the true prevalence of Q fever pneumonia.

  14. Multicountry Prospective Clinical Evaluation of Two Enzyme-Linked Immunosorbent Assays and Two Rapid Diagnostic Tests for Diagnosing Dengue Fever

    Science.gov (United States)

    Dauner, Allison L.; Valks, Andrea; Forshey, Brett M.; Long, Kanya C.; Thaisomboonsuk, Butsaya; Sierra, Gloria; Picos, Victor; Talmage, Sara; Morrison, Amy C.; Halsey, Eric S.; Comach, Guillermo; Yasuda, Chadwick; Loeffelholz, Michael; Jarman, Richard G.; Fernandez, Stefan; An, Ung Sam; Kochel, Tadeusz J.; Jasper, Louis E.; Wu, Shuenn-Jue L.

    2015-01-01

    We evaluated four dengue diagnostic devices from Alere, including the SD Bioline Dengue Duo (nonstructural [NS] 1 Ag and IgG/IgM), the Panbio Dengue Duo Cassette (IgM/IgG) rapid diagnostic tests (RDTs), and the Panbio dengue IgM and IgG capture enzyme-linked immunosorbent assays (ELISAs) in a prospective, controlled, multicenter study in Peru, Venezuela, Cambodia, and the United States, using samples from 1,021 febrile individuals. Archived, well-characterized samples from an additional 135 febrile individuals from Thailand were also used. Reference testing was performed on all samples using an algorithm involving virus isolation, in-house IgM and IgG capture ELISAs, and plaque reduction neutralization tests (PRNT) to determine the infection status of the individual. The primary endpoints were the clinical sensitivities and specificities of these devices. The SD Bioline Dengue Duo had an overall sensitivity of 87.3% (95% confidence interval [CI], 84.1 to 90.2%) and specificity of 86.8% (95% CI, 83.9 to 89.3%) during the first 14 days post-symptom onset (p.s.o.). The Panbio Dengue Duo Cassette demonstrated a sensitivity of 92.1% (87.8 to 95.2%) and specificity of 62.2% (54.5 to 69.5%) during days 4 to 14 p.s.o. The Panbio IgM capture ELISA had a sensitivity of 87.6% (82.7 to 91.4%) and specificity of 88.1% (82.2 to 92.6%) during days 4 to 14 p.s.o. Finally, the Panbio IgG capture ELISA had a sensitivity of 69.6% (62.1 to 76.4%) and a specificity of 88.4% (82.6 to 92.8%) during days 4 to 14 p.s.o. for identification of secondary dengue infections. This multicountry prospective study resulted in reliable real-world performance data that will facilitate data-driven laboratory test choices for managing patient care during dengue outbreaks. PMID:25588659

  15. Evaluation of an egg yolk enzyme-linked immunosorbent assay antibody test and its use to assess the prevalence of Mycoplasma gallisepticum infection in laying hens in Italy

    Directory of Open Access Journals (Sweden)

    Marco Tamba

    2010-01-01

    Full Text Available The prevalence of Mycoplasma gallisepticum infection in commercial layers was established by the presence of antibodies in eggs. Saline-extracted yolks were used with a commercial enzyme-linked immunosorbent assay kit. For the prevalence study, yolks from 30 eggs were obtained from each of 66 flocks coming from 36 layer farms. The prevalence of egg antibodies to Mycoplasma gallisepticum was 33.3% in single-age farms and 77.8% in multi-age farms. In 27 flocks, antibody titers were compared with results obtained from blood samples taken in the same flock and in the same period and analyzed with the same kit. This study has confirmed that egg yolk enzyme-linked immunosorbent assay antibody test is a suitable and practical approach for assessing the flock prevalence of Mycoplasma gallisepticum infection in layer hens.

  16. A simplification of the enzyme-linked immunospot technique. Increased sensitivity for cells secreting IgG antibodies to Haemophilus influenzae type b capsular polysaccharide

    DEFF Research Database (Denmark)

    Barington, T; Sparholt, S; Juul, L

    1992-01-01

    A simplified enzyme-linked immunospot (ELISPOT) technique is described for the detection of cells secreting antibodies to tetanus toxoid (TT), diphtheria toxoid (DT) or Haemophilus influenzae type b capsular polysaccharide (PRP). By combining the cell suspension with the enzyme-linked secondary...... antibodies in one incubation, the second incubation and washing procedure could be omitted from the original technique. The simplified assay had the same sensitivity for anti-TT and anti-DT spot-forming cells as the ordinary ELISPOT assay. The IgG anti-PRP spots were, however, improved both in quality...... and in quantity (median: 40% more spots), while the detection of IgM and IgA anti-PRP spot-forming cells was the same in the two techniques. This simplified technique can probably also be used to save time in other antigen systems and should be considered when designing ELISPOT assays for the detection...

  17. Enzyme-Linked Electrochemical Detection of PCR-Amplified Nucleotide Sequences Using Disposable Screen-Printed Sensors. Applications in Gene Expression Monitoring

    Directory of Open Access Journals (Sweden)

    Miroslav Fojta

    2008-01-01

    Full Text Available Electrochemical enzyme-linked techniques for sequence-specific DNA sensingare presented. These techniques are based on attachment of streptavidin-alkalinephosphatase conjugate to biotin tags tethered to DNA immobilized at the surface ofdisposable screen-printed carbon electrodes (SPCE, followed by production andelectrochemical determination of an electroactive indicator, 1-naphthol. Via hybridizationof SPCE surface-confined target DNAs with end-biotinylated probes, highly specificdiscrimination between complementary and non-complementary nucleotide sequences wasachieved. The enzyme-linked DNA hybridization assay has been successfully applied inanalysis of PCR-amplified real genomic DNA sequences, as well as in monitoring of planttissue-specific gene expression. In addition, we present an alternative approach involvingsequence-specific incorporation of biotin-labeled nucleotides into DNA by primerextension. Introduction of multiple biotin tags per probe primer resulted in considerableenhancement of the signal intensity and improvement of the specificity of detection.

  18. Enrichment Double-Antibody Sandwich Indirect Enzyme-Linked Immunosorbent Assay That Uses a Specific Monoclonal Antibody for Sensitive Detection of Ralstonia solanacearum in Asymptomatic Potato Tubers

    Science.gov (United States)

    Caruso, Paola; Gorris, María Teresa; Cambra, Mariano; Palomo, José Luis; Collar, Jesús; López, María M.

    2002-01-01

    Sensitive and specific routine detection of Ralstonia solanacearum in symptomless potato tubers was achieved by efficient enrichment followed by a reliable double-antibody sandwich indirect enzyme-linked immunosorbent assay based on the specific monoclonal antibody 8B-IVIA. This monoclonal antibody reacted with 168 typical R. solanacearum strains and did not recognize 174 other pathogenic or unidentified bacteria isolated from potato. The optimized protocol included an initial enrichment step consisting of shaking the samples in modified Wilbrink broth for 72 h at 29°C. This step enabled specific detection by the enzyme-linked immunosorbent assay of 1 to 10 CFU of R. solanacearum per ml of initial potato extract. Analysis of 233 commercial potato lots by this method provided results that coincided with the results of conventional methods. PMID:12089053

  19. Interaction between Gender and Skill on Competitive State Anxiety Using the Time-to-Event Paradigm: What Roles Do Intensity, Direction, and Frequency Dimensions Play?

    Directory of Open Access Journals (Sweden)

    John E. Hagan

    2017-05-01

    Full Text Available Background and purpose: The functional understanding and examination of competitive anxiety responses as temporal events that unfold as time-to-competition moves closer has emerged as a topical research area within the domains of sport psychology. However, little is known from an inclusive and interaction oriented perspective. Using the multidimensional anxiety theory as a framework, the present study examined the temporal patterning of competitive anxiety, focusing on the dimensions of intensity, direction, and frequency of intrusions in athletes across gender and skill level.Methods: Elite and semi-elite table tennis athletes from the Ghanaian league (N = 90 completed a modified version of Competitive State Anxiety Inventory-2 (CSAI-2 with the inclusion of the directional and frequency of intrusion scales at three temporal phases (7 days, 2 days, and 1 h prior to a competitive fixture.Results: Multivariate Analyses of Variance repeated measures with follow-up analyses revealed significant interactions for between-subjects factors on all anxiety dimensions (intensity, direction, and frequency. Notably, elite (international female athletes were less cognitively anxious, showed more facilitative interpretation toward somatic anxiety symptoms and experienced less frequency of somatic anxiety symptoms than their male counterparts. However, both elite groups displayed appreciable level of self-confidence. For time-to-event effects, both cognitive and somatic anxiety intensity fluctuated whereas self-confidence showed a steady rise as competition neared. Somatic anxiety debilitative interpretation slightly improved 1 h before competition whereas cognitive anxiety frequencies also increased progressively during the entire preparatory phase.Conclusion: Findings suggest a more dynamic image of elite athletes’ pre-competitive anxiety responses than suggested by former studies, potentially influenced by cultural differences. The use of psychological

  20. Interaction between Gender and Skill on Competitive State Anxiety Using the Time-to-Event Paradigm: What Roles Do Intensity, Direction, and Frequency Dimensions Play?

    Science.gov (United States)

    Hagan, John E.; Pollmann, Dietmar; Schack, Thomas

    2017-01-01

    Background and purpose: The functional understanding and examination of competitive anxiety responses as temporal events that unfold as time-to-competition moves closer has emerged as a topical research area within the domains of sport psychology. However, little is known from an inclusive and interaction oriented perspective. Using the multidimensional anxiety theory as a framework, the present study examined the temporal patterning of competitive anxiety, focusing on the dimensions of intensity, direction, and frequency of intrusions in athletes across gender and skill level. Methods: Elite and semi-elite table tennis athletes from the Ghanaian league (N = 90) completed a modified version of Competitive State Anxiety Inventory-2 (CSAI-2) with the inclusion of the directional and frequency of intrusion scales at three temporal phases (7 days, 2 days, and 1 h) prior to a competitive fixture. Results: Multivariate Analyses of Variance repeated measures with follow-up analyses revealed significant interactions for between-subjects factors on all anxiety dimensions (intensity, direction, and frequency). Notably, elite (international) female athletes were less cognitively anxious, showed more facilitative interpretation toward somatic anxiety symptoms and experienced less frequency of somatic anxiety symptoms than their male counterparts. However, both elite groups displayed appreciable level of self-confidence. For time-to-event effects, both cognitive and somatic anxiety intensity fluctuated whereas self-confidence showed a steady rise as competition neared. Somatic anxiety debilitative interpretation slightly improved 1 h before competition whereas cognitive anxiety frequencies also increased progressively during the entire preparatory phase. Conclusion: Findings suggest a more dynamic image of elite athletes’ pre-competitive anxiety responses than suggested by former studies, potentially influenced by cultural differences. The use of psychological skills

  1. Development of direct competitive biomimetic immunosorbent assay based on quantum dot label for determination of trichlorfon residues in vegetables.

    Science.gov (United States)

    Liu, Qiurui; Jiang, Mingdi; Ju, Zeliang; Qiao, Xuguang; Xu, Zhixiang

    2018-06-01

    A direct competitive biomimetic immunosorbent assay method based on molecularly imprinted polymer was developed for the determination of trichlorfon. A CdSe/ZnS quantum dot label was used as the marker. The hydrophilic imprinted film was synthesized directly on the surface of a 96-well plate, and characterized by Fourier-transform infrared spectroscopy and thermo-gravimetric analyses. The method exhibited high stability, selectivity, and sensitivity. Under optimal conditions, the limits of detection and sensitivity of the biomimetic immunosorbent assay method were 9.0 μg L -1 and 5.0 mg L -1 (0.1 mg kg -1 and 62.5 mg kg -1 for vegetable sample), respectively. Low cross-reactivity values of 19.2% and 15.6% were obtained for the structural analogues. Spinach and rape samples spiked with trichlorfon were extracted and determined by this method with recoveries ranging from 83.6% to 91.1%. The method was applied for the detection of trichlorfon residues in leek and cucumber samples, and results correlated well with those obtained using GC. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Performance and reliability of five commercial enzyme-linked immunosorbent assay kits in screening for anti-human immunodeficiency virus antibody in high-risk subjects.

    OpenAIRE

    Ozanne, G; Fauvel, M

    1988-01-01

    Anti-human immunodeficiency virus enzyme-linked immunosorbent assay kits marketed by Electro-Nucleonics Inc. (ENI), Genetic Systems Corp. (GSC), Organon Teknika Inc. (OTI), Ortho Diagnostic Systems Inc. (ODSI), and Wellcome Diagnostics (WD) were evaluated by using 289 randomly selected serum samples from a high-risk population and 53 serum samples likely to produce false-positive results. The radioimmunoprecipitation assay was used as the reference test. Sensitivities ranged from 96.51% (ODSI...

  3. Evaluation of an enzyme-linked immunosorbent assay based on crude leishmania histone proteins for serodiagnosis of human infantile visceral leishmaniasis.

    OpenAIRE

    Lakhal, Sami; Mekki, Salima; Ben-Abda, Imène; Mousli, Mohamed; Amri, Fethi; Aoun, Karim; Bouratbine, Aïda

    2012-01-01

    International audience; Human visceral leishmaniasis (VL) is routinely diagnosed by detecting IgG that specifically binds to Leishmania antigens. The enzyme-linked immunosorbent assay (ELISA) remains a widely used method. However, the biggest challenge remains the choice of antigen with the highest specificity and sensitivity. This study is aimed at assessing the diagnostic performances of crude Leishmania histone (CLH) protein-based ELISAs in Mediterranean VL patients. The CLH proteins were ...

  4. Rapid Detection of Campylobacter coli, C. jejuni, and Salmonella enterica on Poultry Carcasses by Using PCR-Enzyme-Linked Immunosorbent Assay

    OpenAIRE

    Hong, Yang; Berrang, Mark E.; Liu, Tongrui; Hofacre, Charles L.; Sanchez, Susan; Wang, Lihua; Maurer, John J.

    2003-01-01

    Contamination of retail poultry by Campylobacter spp. and Salmonella enterica is a significant source of human diarrheal disease. Isolation and identification of these microorganisms require a series of biochemical and serological tests. In this study, Campylobacter ceuE and Salmonella invA genes were used to design probes in PCR-enzyme-linked immunosorbent assay (ELISA), as an alternative to conventional bacteriological methodology, for the rapid detection of Campylobacter jejuni, Campylobac...

  5. Effects of experience on the dimensions of intensity, direction and frequency of the competitive anxiety and self-confidence: A study in athletes of individual and team sports

    Directory of Open Access Journals (Sweden)

    Marcos Gimenes Fernandes

    2014-06-01

    Full Text Available The present study had the following objectives: i to examine the inter-scale correlations between the three dimensions of responses (intensity, direction and frequency of the CSAI-2R and its relationship with competitive experience, and ii evaluate the effect of competitive experience anxiety (cognitive and somatic and self-confidence in the total sample and for different types of modalities (individual vs. team. The sample consisted of 267 athletes (196 male and 71 female, of different sports, aged between 18 and 40 years (M = 24.30, SD = 5.62. Athletes completed the Brazilian version of the CSAI-2, which included the addition of the dimensions of direction and frequency response. Spearman test and Manova were used for the data analysis. Overall, it was found that the competitive experience has a high multivariate and significant effect on the dimensions of competitive anxiety. Both individual and team athletes with low competitive experience showed a trend to report lower levels of self-confidence intensity, compared to counterparts with high competitive experience. These results were discussed in view of the theoretic framework and practical implications planning Sport Psychology intervention programs in local athletes with different backgrounds.

  6. The “Direct Care of Health” and the Ethics as Expression of Specific Professionals Competition in the Superior Technician in Infirmary in Ecuador (TSE

    Directory of Open Access Journals (Sweden)

    Lic. Lenny Mariscal-San Martin

    2015-10-01

    Full Text Available The gratuidad of the Education Superior Public Ecuadorian offers possibilities of social character and opportunities to the Superior Technician of Infirmary (TSE. nevertheless, the Technological Institute Bolivariano in Technology of Guayaquil yearns to form technical professionals that contribute an academic excellence, able to show competitions in its practical performance, fundamentally, in the care of the health of the patients, supported in scientific bases and necessary foundations for the genuineness and autonomy of the profession.  However, it is insufficient a focus integral planned environment to the development of specific professional competition associated to the ethics and the direct care of health, interest of the study continued by the investigators.Keywords:  Ethical formation of the TSE, Ethics, Bioethics, ethical competition, professional competitions.

  7. An ultra-sensitive monoclonal antibody-based enzyme-linked immunosobent assay for dibutyl phthalate in human urinary

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lifang [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Science, Zhejiang University, Hangzhou 310058 (China); Lei, Yajing [Hangzhou EPIE Bio-detection Technology Limited, Hangzhou 310051 (China); Zhang, Dai; Ahmed, Shabbir [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Science, Zhejiang University, Hangzhou 310058 (China); Chen, Shuqing, E-mail: chenshuqing@zju.edu.cn [Institute of Pharmacology, Toxicology and Biochemical Pharmaceutics, College of Pharmaceutical Science, Zhejiang University, Hangzhou 310058 (China)

    2016-01-15

    Dibutyl phthalate (DBP) has been extensively used as a plasticizer in many daily products, which is highly toxic to human, notably affecting the reproductive and developmental function. As the previous method is expensive, time-consuming, low sensitivity and just focused on the environment. Present study was aimed to establish an ultra-sensitive and simple method based on good quality monoclonal antibody, applying to evaluate excretion level of DBP in urine samples of Chinese population directly. A monoclonal antibody was generated and characterized after fusion of myeloma cells with spleen cells isolated from BALB/c mouse. The mouse was previously immunized using a specially designed amino derivative of DBP conjugated with bovine serum albumin (BSA) as immunogen. Cross-reactivity values of the monoclonal antibody against DBP, di-isobutyl phthalate (DIBP) were observed 100% and 1.25%, while for dimethyl phthalate (DMP), butyl benzyl phthalate (BBP) and didecyl phthalate (DDP) the values were < 0.06%. The standard curve was constructed at 0–50 ng mL{sup −1} and good linearity (R{sup 2} = 0.994) was achieved. The observed IC{sub 50} (7.34 ng mL{sup −1}) and LOD (0.06 ng mL{sup −1}) values was improved 1000-fold to polyclonal antibody and 5-fold to other monoclonal antibodies. A total 1246 urine samples were analyzed and the detection frequency of DBP was observed 72.87% by ic-ELISA. The 95th percentile and mean concentration of DBP were 12.07 and 3.00 ng mL{sup −1}. Acceptable recovery rates of DBP were 97.8–114.3% and coefficients variation 5.93–11.09%. The concentrations of DBP in females were found significantly higher (p < 0.05) than males. Similarly, the DBP in middle aged and low educated individuals was found higher (p < 0.001) than the others. Considering the adverse health effects, DBP internal exposure in the Chinese population should be reduced. The ic-ELISA method has been proved as a cost effective, specific, and highly sensitive screening

  8. Direct and indirect effects of a dense understory on tree seedling recruitment in temperate forests: habitat-mediated predation versus competition

    Science.gov (United States)

    Alejandro A. Royo; Walter P. Carson

    2008-01-01

    In forests characterized by a dense woody and herbaceous understory layer, seedling recruitment is often directly suppressed via interspecific competition. Alternatively, these dense layers may indirectly lower tree recruitment by providing a haven for seed and seedling predators that prey on neighboring plant species. To simultaneously...

  9. Detection of IgM antibodies against canine distemper virus in dog and mink sera employing enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    Blixenkrone-Møller, M; Pedersen, I R; Appel, M J; Griot, C

    1991-01-01

    An enzyme-linked immunosorbent assay (ELISA) for the detection of IgM antibodies against canine distemper virus (CDV) in canine and mink serum is described. The diagnostic potential of this technique was evaluated by analyzing sera from natural or experimental infections in dog and mink and negative control sera. These results were compared with results obtained in the developed CDV IgG ELISA and in the virus neutralization test. The IgM test, which requires only a single serum specimen, is a useful method for diagnosing current or recent CDV infections in dog and mink.

  10. Generation of monoclonal antibodies against peptidylarginine deiminase 2 (PAD2) and development of a PAD2-specific enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Damgaard, Dres; Palarasah, Yaseelan; Skjødt, Karsten

    2014-01-01

    The enzyme peptidylarginine deiminase 2 (PAD2) has been associated with inflammatory diseases, such as rheumatoid arthritis and neurodegenerative diseases including multiple sclerosis. To investigate the association of various diseases with extracellular PAD2, we raised monoclonal antibodies (m......Abs) against rabbit PAD2 and evaluated their cross-reactivity with human PAD2 by indirect enzyme-linked immunosorbent assay (ELISA), western blotting and immunohistological staining of inflamed synovial tissue. Moreover, we established a sandwich ELISA detecting human PAD2, based on two different monoclonal...... diseases....

  11. Detection of single nucleotide polymorphisms in p53 mutation hotspots and expression of mutant p53 in human cell lines using an enzyme-linked electrochemical assay

    Czech Academy of Sciences Publication Activity Database

    Horáková Brázdilová, Petra; Šimková, Eva; Vychodilová, Zdenka; Brázdová, Marie; Fojta, Miroslav

    2009-01-01

    Roč. 21, č. 15 (2009), s. 1723-1729 ISSN 1040-0397 R&D Projects: GA ČR(CZ) GA203/07/1195; GA AV ČR(CZ) IAA400040901; GA MŠk(CZ) LC06035 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : enzyme-linked electrochemical assay * SNP typing * p53 mutation Subject RIV: AQ - Safety, Health Protection, Human - Machine Impact factor: 2.630, year: 2009

  12. Quantification of urinary 5-hydroxyindoleacetic acid by in-house nitrosonaphthol reaction compared with nitrosonaphthol micro column chromatography and enzyme-linked immunosorbent assay

    Directory of Open Access Journals (Sweden)

    Joyce Matie Kinoshita da Silva

    2014-06-01

    Full Text Available The aim of this study was to compare the colorimetric "kit" and enzyme-linked immunosorbent assay (ELISA methods to quantify urinary 5-hydroxyindoleacetic acid through the Goldenberg's technique, exploring the potential of replacing it. 24-hour urine samples were tested by Goldenberg's assay and compared with kits. The agreement was almost perfect for the comparison of Goldenberg's assay with both colorimetric kit, and with ELISA kit, considering ≤ 7.5 mg/24h normal cutoff value. Therefore, both "kits" would be good alternatives to Goldenberg's technique due to practicality and agreement between values.

  13. Comparison of enzyme-linked immunosorbent assay, radioimmunoassay, complement fixation, anticomplement immunofluorescence and passive haemaglutination techniques for detecting cytomegalovirus IgG antibody

    International Nuclear Information System (INIS)

    Booth, J.C.; Hannington, G.; Bakir, T.M.F.; Stern, H.; Kangro, H.; Griffiths, P.D.; Heath, R.B.

    1982-01-01

    The radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA) techniques were found to be comparable in sensitivity and specificity for detecting cytomegalovirus IgG antibody, and 10 to 100 times more sensitive than complement-fixation (CF), anticomplement immunofluorescence (ACIF) and passive haemagglutination (PHA). In screening tests for antibody, the frequency of false-positive and -negative results was 0.6% for RIA and ELISA, 1.5% for CF, 1.6% for ACIF and 3.6% for PHA. PHA was the least satisfactory test, largely because of technical problems. (author)

  14. Technical note: Development of an enzyme-linked immunosorbent assay for the determination of florfenicol and thiamphenicol in swine feed.

    Science.gov (United States)

    Luo, P J; Jiang, W X; Chen, X; Shen, J Z; Wu, Y N

    2011-11-01

    One polyclonal antibody against florfenicol and thiamphenicol was produced and a competitive ELISA was developed for the detection of florfenicol and thiamphenicol in swine feed. The ELISA gave a 50% inhibiting concentration of 1.02 ng/mL for florfenicol. For swine feed fortified with 0.05 to 3.0 mg/kg, the interassay recoveries of florfenicol and thiamphenicol ranged from 86.4 to 118.6%, whereas intraassay recoveries of both drug ranged from 90.1 to 126.5% with less than 15% CV. Results obtained from HPLC-tandem mass spectrometry indicated this ELISA procedure could be used as a convenient method for rapid screening of florfenicol and thiamphenicol in swine feed.

  15. DNA Polymerase Fidelity: Comparing Direct Competition of Right and Wrong dNTP Substrates with Steady State and Presteady State Kinetics†

    Science.gov (United States)

    Bertram, Jeffrey G.; Oertell, Keriann; Petruska, John; Goodman, Myron F.

    2009-01-01

    DNA polymerase fidelity is defined as the ratio of right (R) to wrong (W) nucleotide incorporations when dRTP and dWTP substrates compete at equal concentrations for primer extension at the same site in the polymerase-primer-template DNA complex. Typically, R incorporation is favored over W by 103 – 105, even in the absence of 3′-exonuclease proofreading. Straightforward in principal, a direct competition fidelity measurement is difficult to perform in practice because detection of a small amount of W is masked by a large amount of R. As an alternative, enzyme kinetics measurements to evaluate kcat/Km for R and W in separate reactions are widely used to measure polymerase fidelity indirectly, based on a steady-state derivation by Fersht. A systematic comparison between direct competition and kinetics has not been made until now. By separating R and W products using electrophoresis, we have successfully made accurate fidelity measurements for directly competing R and W dNTP substrates for 9 of the 12 natural base mispairs. We compare our direct competition results with steady state and presteady state kinetic measurements of fidelity at the same template site, using the proofreading-deficient mutant of Klenow Fragment (KF−) DNA polymerase. All the data are in quantitative agreement. PMID:20000359

  16. Application of enzyme linked immunosorbent assays for the diagnosis of bovine brucellosis in Rio Grande do Sul, Brazil

    International Nuclear Information System (INIS)

    Poester, F.P.; Ramos, E.T.; Thiesen, S.V.

    1998-01-01

    The results of an indirect ELISA (I-ELISA) and a competitive ELISA (C-ELISA) for detection of antibody to Brucella abortus in cattle were compared with those of conventional serological tests. The sensitivity of I-Elisa using 230 sera from infected animals was 98.6% and the specificity in 720 sera from brucellosis-free animals was 98.2%. The C-ELISA when tested in 94 positive sera and 91 negative sera was 100% sensitive and specific. The relative sensitivity and specificity of I-ELISA compared to C-ELISA in 582 sera from groups of animals vaccinated with S19 by different routes and doses was respectively 64% and 100%. When comparing five serological tests on sera from vaccinated animals, the specificity was 94% for C-ELISA, 93% for 2-mercaptoethanol (2ME), 88% for Rose Bengal Plate test (RBPT), 84% for Slow Tube Agglutination test (SAT) and 34% for I-ELISA. It can be concluded from this study that the RBPT gave less false positive results than the I-ELISA in vaccinated animals and the C-ELISA is a good confirmatory test with the advantage of distinguishing the antibody response due to vaccination from that resulting from infection with Brucella abortus. (author)

  17. Enzyme-linked immunosorbent assay (ELISA) for brown trout vitellogenin for use in the detection of environmental estrogens

    Energy Technology Data Exchange (ETDEWEB)

    Gamble, A.; Solomon, K. [Univ. of Guelph, Ontario (Canada); Sherry, J.; Fielden, M.; Hodson, P. [Environment Canada, Budington, Ontario (Canada)

    1995-12-31

    Vitellogenin (Vg) is a phospholipoprotein egg yolk precursor found in females of most oviparous vertebrates. Vitellogenin induction in male teleosts is known to result from exposure to xenoestrogens. Using antisera for brown trout Vg, the authors adapted an (ELISA) for in vivo Vg in brown trout (Salmo trutta). The authors will use the Vg bioassay to detect the estrogenic effects of effluents, contaminated sediments and suspect chemicals. Vg production in male fish was induced by intraperitoneal injection of 11-B estradiol. Harvested and purified Vg was used in an assay based on competition between soluble Vg and Vg adsorbed in microtitre wells for binding sites on rabbit anti-Vg antibody. Adsorbed Vg-antibody complexes were subsequently revealed by an alkaline phosphatase technique. The reaction intensity was measured as absorbance and used to quantify the amount of antibody bound to adsorbed Vg. The amount of bound antibody was inversely proportional to the amount of vitellogenin in the fish plasma. Preliminary results show that the assay`s working range, corresponding to 80--20% binding, was 14--355 ng/ml, with 50% binding (IC{sub 50}) around 71 ng/mi. Calculated at 50% binding, the intra-assay variation was less than 8% (n = 9) and the inter-assay variation was also less than 8% (n =4). The assay`s sensitivity was 0.067 ng/mi and the limit of detection was 0.134 ng/ml. The authors will present the results of Vg bioassays for the presence of estrogen mimics in industrial effluent.

  18. Mixing, entropy and competition

    International Nuclear Information System (INIS)

    Klimenko, A Y

    2012-01-01

    Non-traditional thermodynamics, applied to random behaviour associated with turbulence, mixing and competition, is reviewed and analysed. Competitive mixing represents a general framework for the study of generic properties of competitive systems and can be used to model a wide class of non-equilibrium phenomena ranging from turbulent premixed flames and invasion waves to complex competitive systems. We demonstrate consistency of the general principles of competition with thermodynamic description, review and analyse the related entropy concepts and introduce the corresponding competitive H-theorem. A competitive system can be characterized by a thermodynamic quantity—competitive potential—which determines the likely direction of evolution of the system. Contested resources tend to move between systems from lower to higher values of the competitive potential. There is, however, an important difference between conventional thermodynamics and competitive thermodynamics. While conventional thermodynamics is constrained by its zeroth law and is fundamentally transitive, the transitivity of competitive thermodynamics depends on the transitivity of the competition rules. Intransitivities are common in the real world and are responsible for complex behaviour in competitive systems. This work follows ideas and methods that have originated from the analysis of turbulent combustion, but reviews a much broader scope of issues linked to mixing and competition, including thermodynamic characterization of complex competitive systems with self-organization. The approach presented here is interdisciplinary and is addressed to the general educated readers, whereas the mathematical details can be found in the appendices. (comment)

  19. Consumer-oriented health care reform strategies: a review of the evidence on managed competition and consumer-directed health insurance.

    Science.gov (United States)

    Buchmueller, Thomas C

    2009-12-01

    For many years, leading health care reform proposals have been based on market-oriented strategies. In the 1990s, a number of reform proposals were built around the concept of "managed competition," but more recently, "consumer-directed health care" models have received attention. Although price-conscious consumer demand plays a critical role in both the managed competition and consumer-directed health care models, the two strategies are based on different visions of the health care marketplace and the best way to use market forces to achieve greater systemwide efficiencies. This article reviews the research literature that tests the main hypotheses concerning the two policy strategies. Numerous studies provide consistent evidence that consumers' health plan choices are sensitive to out-of-pocket premiums. The elasticity of demand appears to vary with consumers' health risk, with younger, healthier individuals being more price sensitive. This heterogeneity increases the potential for adverse selection. Biased risk selection also is a concern when the menu of health plan options includes consumer-directed health plans. Several studies confirm that such plans tend to attract healthier enrollees. A smaller number of studies test the main hypothesis regarding consumer-directed health plans, which is that they result in lower medical spending than do more generous plans. These studies find little support for this claim. The experiences of employers that have adopted key elements of managed competition are generally consistent with the key hypotheses underlying that strategy. Research in this area, however, has focused on only a narrow range of questions. Because consumer-directed health care is such a recent phenomenon, research on this strategy is even more limited. Additional studies on both topics would be valuable.

  20. Measurement of antibody to Dermatophilus congolensis in sera from cattle in the west of Scotland by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Lloyd, D H

    1981-11-07

    Serum antibody titres to Dermatophilus congolensis demonstrated by an enzyme-linked immunosorbent assay (ELISA) in young steers and in adult cows from an Ayrshire herd showed a bimodal distribution and provided evidence of subclinical infection. Very high titres detected in sera from crossbred Galloway steers were indicative of recent or existing infection which may have been masked by concurrent ringworm. The ELISA is a sensitive and technically simple method which enables sera to be screened for evidence of infection by D congolensis which may otherwise pass unrecognised. Such infections may be of importance not only in the epidemiology of the disease in farm animals but also as a potential source of infection for man and his domestic pets.

  1. DETECTION OF OXYTETRACYCLINE IN BROILER CHICKEN MEAT MARKETED IN SEVERAL CITIES IN JAVA ISLAND USING ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA METHOD

    Directory of Open Access Journals (Sweden)

    R. Widiastuti

    2015-09-01

    Full Text Available Oxytetracycline (OTC is one of the tetracycline (TCs broad-spectrum antibiotics widely used inthe chicken industry. However, improper use of OTC with excessive doses potentially leads to residueformation in animal products that can be harmful to consumers in the form of allergic reaction orresistance. This study aimed to detect OTC residues in broiler chicken meat, marketed in traditionalmarkets and supermarkets in Depok, Bekasi, Bandung, Cilegon, Surakarta and Yogyakarta using indirectcompetitive enzyme-linked immunosorbent assay (icELISA method. The analyses of 67 broiler meatsamples showed only 1 (1.5% sample was positive for the OTC residue at 86.1 ng/g which meant belowthe maximum residue limits of permissible OTC (100 ng/g. Nevertheless, a stricter regulation for theuse of OTC in the poultry industry and the monitoring of its residue in chicken products prior tomarketing is still necessary to avoid the adverse effects of the residue present in animal products.

  2. Development and evaluation of a blocking enzyme-linked immunosorbent assay and virus neutralization assay to detect antibodies to viral hemorrhagic septicemia virus

    Science.gov (United States)

    Wilson, Anna; Goldberg, Tony; Marcquenski, Susan; Olson, Wendy; Goetz, Frederick; Hershberger, Paul; Hart, Lucas M.; Toohey-Kurth, Kathy

    2014-01-01

    Viral hemorrhagic septicemia virus (VHSV) is a target of surveillance by many state and federal agencies in the United States. Currently, the detection of VHSV relies on virus isolation, which is lethal to fish and indicates only the current infection status. A serological method is required to ascertain prior exposure. Here, we report two serologic tests for VHSV that are nonlethal, rapid, and species independent, a virus neutralization (VN) assay and a blocking enzyme-linked immunosorbent assay (ELISA). The results show that the VN assay had a specificity of 100% and sensitivity of 42.9%; the anti-nucleocapsid-blocking ELISA detected nonneutralizing VHSV antibodies at a specificity of 88.2% and a sensitivity of 96.4%. The VN assay and ELISA are valuable tools for assessing exposure to VHSV.

  3. Bilirubin oxidase label for an enzyme-linked affinity assay with O2 as substrate in a neutral pH NACL solution.

    Science.gov (United States)

    Kim, Hyug-Han; Zhang, Yongchao; Heller, Adam

    2004-04-15

    Laccase, a copper enzyme catalyzing the four-electron reduction of O(2) to water, has been shown by others to be a useful label in enzyme-linked immunoassays, in which the substrate is ambient O(2) instead of an added chemical, such as hydrogen peroxide, or a phosphate ester of a phenol. Laccase-catalyzed O(2) reduction is, however, inhibited by halides, which complex the enzyme's copper ions. Replacement of laccase by bilirubin oxidase, a copper enzyme retaining its maximal activity at high chloride concentrations and at pH 7.2, allows enzyme-amplified affinity assays with O(2) as the substrate in neutral-pH chloride solutions, exemplified here by the assay of DNA, the duplexes of which are unstable at low ionic strength but are stable in strong NaCl solutions.

  4. Seroprevalence study of Equine rhinitis B virus (ERBV) in Australian weanling horses using serotype-specific ERBV enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Horsington, Jacquelyn; Hartley, Carol A; Gilkerson, James R

    2013-09-01

    Respiratory infections are a major burden in the performance horse industry. Equine rhinitis B virus (ERBV) has been isolated from horses displaying clinical respiratory disease, and ERBV-neutralizing antibodies have been detected in 50-80% of horses in reported surveys. Current ERBV isolation and detection methods may underestimate the number of ERBV-positive animals and do not identify multiple serotype infections. The aim of the current study was to develop a serotyping ERBV antibody-detection enzyme-linked immunosorbent assay (ELISA) and examine the seroprevalence of ERBV in a group of Australian weanling horses. ELISAs with high sensitivity and specificity were developed. The seroprevalence of ERBV in the weanling horses was high (74-86%); ERBV-3 antibodies were most prevalent (58-62%) and ERBV-2 antibodies were least prevalent (10-16%). Many horses were seropositive to 2 or more serotypes. All 3 serotypes of ERBV were detected, and concurrent positivity to multiple serotypes was common.

  5. Quantitation of pulmonary surfactant protein SP-B in the absence or presence of phospholipids by enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Oviedo, J M; Valiño, F; Plasencia, I

    2001-01-01

    We have developed an enzyme-linked immunosorbent assay (ELISA) that uses polyclonal or monoclonal anti-surfactant protein SP-B antibodies to quantitate purified SP-B in chloroform/methanol and in chloroform/methanol extracts of whole pulmonary surfactant at nanogram levels. This method has been...... used to explore the effect of the presence of different phospholipids on the immunoreactivity of SP-B. Both polyclonal and monoclonal antibodies produced reproducible ELISA calibration curves for methanolic SP-B solutions with protein concentrations in the range of 20-1000 ng/mL. At these protein...... pronounced changes on the conformation of SP-B when the solvent was evaporated and dry lipid-protein films were formed, a necessary step to expose protein to antibodies in ELISA. Under these conditions, negatively charged lipids, but not zwitterionic ones, induced a marked decrease on the ellipticity of SP...

  6. THE DIRECTIONS OF IMPROVEMENT OF A COMPETITION POLICY ON THE BASIS OF DEVELOPMENT OF CONTRACT FORMS OF JOINT ACTIVITY OF SMALL AND LARGE BUSINESS

    Directory of Open Access Journals (Sweden)

    N. A. Serebriakova

    2014-01-01

    Full Text Available Summary: The analysis of the foreign economic theory and practice of antimonopoly regulation, the principles of the Russian civil law and the antitrust law, allows to formulate a number of the basic principles and approaches to an assessment of influence of different types of the contract relations on efficiency of use of public resources, welfare of consumers and the competitive environment, the research basis presented in this article also consists in it. Support of the competition is guaranteed by the Constitution of the Russian Federation, is one of bases of the constitutional system of the Russian Federation, and also relevance of a subject of research is confirmed by a constant priority of a state policy it. Development of the competition in economy is a multidimensional task which decision substantially depends on efficiency of carrying out a state policy in a wide range of the directions: from macroeconomic policy, creation of favorable investment climate, including development of financial and tax system, decrease in administrative and infrastructure barriers, before protection of the rights of citizens and national policy. Due to the complexity of a task dynamic landmark approach to work on development of a competition policy in connection with development of contract forms of joint activity of small and large business in the Russian Federation and to formation of the respective directions is necessary. For research by authors of research the following methods are chosen: a statistical method, a reference method to value, a comparative method, system approach, a historical method and a method of the economic analysis of the public relations and the right. Research covers the latest sources in the field reflecting the last economic and standard and legal changes, in particular, them treat: the statistical given, expert estimates, regulations, acts of judicial and administrative practice, scientific publications of economists

  7. Exploiting Nanobodies in the Detection and Quantification of Human Growth Hormone via Phage-Sandwich Enzyme-Linked Immunosorbent Assay

    Directory of Open Access Journals (Sweden)

    Hossam Murad

    2017-05-01

    Full Text Available BackgroundMonitoring blood levels of human growth hormone (hGH in most children with short stature deficiencies is crucial for taking a decision of treatment with extended course of daily and expensive doses of recombinant hGH (rhGH or Somatropin®. Besides, misusing of rhGH by sportsmen is banned by the World Anti-Doping Agency and thus sensitive GH-detecting methods are highly welcome in this field. Nanobodies are the tiniest antigen-binding entity derived from camel heavy chain antibodies. They were successfully generated against numerous antigens including hormones.MethodsA fully nanobody-based sandwich ELISA method was developed in this work for direct measurement of GH in biological samples.ResultsTwo major characteristics of nanobody were exploited for this goal: the robust and stable structure of the nanobody (NbGH04 used to capture hGH from tested samples, and the great ability of tailoring, enabling the display of the anti-GH detector nanobody (NbGH07 on the tip of M13-phage. Such huge, stable, and easy-to-prepare phage-Nb was used in ELISA to provide an amplified signal. Previously, NbGH04 was retrieved on immobilized hGH by phage display from a wide “immune” cDNA library prepared from a hGH-immunized camel. Here, and in order to assure epitope heterogeneity, NbGH07 was isolated from the same library using NbGH04-captured hGH as bait. Interaction of both nanobodies with hGH was characterized and compared with different anti-GH nanobodies and antibodies. The sensitivity (~0.5 ng/ml and stability of the nanobody-base sandwich ELISA were assessed using rhGH before testing in the quantification of hGH in blood sera and cell culture supernatants.ConclusionIn regard to all advantages of nanobodies; stability, solubility, production affordability in Escherichia coli, and gene tailoring, nanobody-based phage sandwich ELISA developed here would provide a valuable method for hGH detection and quantification.

  8. Direct observation of competition between superconductivity and charge density wave order in YBa2Cu3O6.67

    DEFF Research Database (Denmark)

    Chang, J.; Blackburn, E.; Holmes, A. T.

    2012-01-01

    Superconductivity often emerges in the proximity of, or in competition with, symmetry-breaking ground states such as antiferromagnetism or charge density waves (CDW). A number of materials in the cuprate family, which includes the high transition-temperature (high-Tc) superconductors, show spin...... and charge density wave order. Thus a fundamental question is to what extent do these ordered states exist for compositions close to optimal for superconductivity. Here we use high-energy X-ray diffraction to show that a CDW develops at zero field in the normal state of superconducting YBa2Cu3O6.67 (Tc= 67 K......). This sample has a hole doping of 0.12 per copper and a well-ordered oxygen chain superstructure. Below Tc, the application of a magnetic field suppresses superconductivity and enhances the CDW. Hence, the CDW and superconductivity in this typical high-Tc material are competing orders with similar energy...

  9. EDITORIAL: Physics competitions Physics competitions

    Science.gov (United States)

    Jordens, H.; Mathelitsch, L.

    2009-11-01

    less are invited to present their research and results as a paper, in the style typically published by scientific journals. The student is allowed to choose a topic within the broad scope of physics, including cross-over fields such as astro- or biophysics. In 2008 over 2000 papers were submitted and 25 awards were given. In line with 'First Step' is the International Conference for Young Scientists (ICYS) [7]. The conference started in 1994 in Viségrad, Hungary. Here too, the participants present the results of their research, not by submitting a research paper but by giving a presentation to an audience of peers and a jury of specialists. The subjects of the presentations are in physics, mathematics, computer science, environmental sciences, engineering or life sciences. The jury awards the presentations according to the level of the content and the presentation. The last three competitions presented here are younger and did not start within Eastern European countries. The International Olympics of Astrophysics and Astronomy (IOAA) was organized for the second time in Bandung, Indonesia in 2008 and 24 countries participated [8]. As the title of the competition indicates, problems are directed towards theoretical and experimental aspects of astronomy. A little bit older is the European Union Science Olympiad (EUSO) [9]. This started in 2001, but the first competition took place in Dublin, Ireland, in 2003. The last competition was organized in March-April 2009 in Murcia, Spain. This competition addresses younger students, aged 17 years or less. It tries to combine biology, chemistry and physics. Although the problems are formulated in an interdisciplinary way, the students remain specialists, one in physics and the others in biology and chemistry. For even younger students, there is the International Junior Science Olympiad (IJSO) [10]. This competition started in December 2004 on the initiative of Professor Masno Ginting from Indonesia. The last competition took

  10. The Effect of Different Methods of Fermentation on the Detection of Milk Protein Residues in Retail Cheese by Enzyme-Linked Immunosorbent Assay (ELISA).

    Science.gov (United States)

    Ivens, Katherine O; Baumert, Joseph L; Hutkins, Robert L; Taylor, Steve L

    2017-11-01

    Milk and milk products are among the most important allergenic food ingredients, both in the United States and throughout the world; cheeses are among the most important of these milk products. Milk contains several major antigenic proteins, each with differing susceptibilities to proteolytic enzymes. The extent of proteolysis in cheese varies as a result of conditions during manufacture and ripening. Proteolysis has the potential to degrade antigenic and allergenic epitopes that are important for residue detection and elicitation of allergic reactions. Commercial enzyme-linked immunosorbent assays (ELISAs) are not currently validated for use in detecting residues in hydrolyzed or fermented food products. Eighteen retail cheeses produced using 5 different styles of fermentation were investigated for detectable milk protein residues with 4 commercial ELISA kits. Mozzarella, Swiss, Blue, Limburger, and Brie cheeses were assessed. The Neogen Veratox® Casein and Neogen Veratox® Total Milk kits were capable of detecting milk residues in most cheeses evaluated, including blue-veined cheeses that exhibit extensive proteolysis. The other 2 ELISA kits evaluated, r-Biopharm® Fast Casein and ELISA Systems™ Casein, can detect milk residues in cheeses other than blue-veined varieties. ELISA results cannot be quantitatively compared among kits. The quantitative reliability of ELISA results in detection of cheese residues is questionable, but some methods are sufficiently robust to use as a semi-quantitative indication of proper allergen control for the validation of cleaning programs in industry settings. Many commercially available enzyme-linked immunosorbent assays (ELISAs) are not validated for detection of allergenic residues in fermented or hydrolyzed products. This research seeks to determine if commercial milk ELISAs can detect milk residues in varieties of cheese that have undergone different styles of fermentation and different degrees of proteolysis. Only certain

  11. Human immune response to botulinum pentavalent (ABCDE) toxoid determined by a neutralization test and by an enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Siegel, L S

    1988-11-01

    To determine the immune status of persons receiving botulinum pentavalent (ABCDE) toxoid and to evaluate the effectiveness of the vaccine, we surveyed immunized individuals for neutralizing antibodies to type A and to type B botulinum toxins. After the primary series of three immunizations administered at 0, 2, and 12 weeks, 21 of 23 persons tested (91%) had a titer for type A that was greater than or equal to 0.08 international units (IU)/ml, and 18 (78%) had a titer for type B of greater than or equal to 0.02 IU/ml. (One international unit is defined as the amount of antibody neutralizing 10,000 mouse 50% lethal doses of type A or B botulinum toxin). Just before the first annual booster, 10 of 21 (48%) and 14 of 21 (67%) people lacked a detectable titer for type A and for type B, respectively. After the first booster, all individuals tested had a demonstrable titer to both types A and B. Of 77 persons who had previously received from one to eight boosts of the toxoid, 74 (96%) had an A titer of greater than or equal to 0.25 IU/ml and would not require an additional booster, according to the recommendations of the Centers for disease Control. However, only 44 of 77 (57%) had a B titer of greater than or equal to 0.25 IU/ml. In each group by booster number, even the group having had eight boosts, at least one person would require reimmunization on the basis of B titer. There was a wide range of antibody levels among individuals at the same point in the immunization scheme. Results from an enzyme linked immunosorbent assay, with purified type A or type B neurotoxin as the capture antigen, were compared with neutralization test results on 186 serum samples for type A and 168 samples for type B. Statistically, the correlation coefficients for results from the two assays were high (r = 0.69, P < 0.0001, for type A and r = 0.77, P < 0.0001, for type B). However, due to the wide dispersion of values obtained, using enzyme-linked immunosorbent assay results to predict

  12. Summary of field trials using the direct and competitive enzyme immunoassays for detection of antibody to brucella abortus

    International Nuclear Information System (INIS)

    Nielsen, K.; Gall, D.

    1998-01-01

    Two indirect and two competitive enzyme immunoassays for detection of antibody to Brucella abortus, validated elsewhere, were field tested in five different Latin American laboratories. Testing was performed according to standardised protocols using sera obtained in each area. Sera from B. abortus infected herds, from vaccinated (but serologically negative in a screening test) and non-vaccinated cattle were tested in each assay and compared to the results obtained with conventional diagnostic tests used for diagnosis of brucellosis in each country. Relative sensitivity and specificity values were calculated for each country as well as a weighted summary combining the data from all the participating laboratories. The result demonstrate that all ELISAs performed as well as, or better than, the conventional aerological tests. Given the inherent errors in the use of the latter in the diagnosis of brucellosis, it is recommended that the ELISAs described here be considered as replacements for the conventional tests. The CELISA using the lipopolysaccharide antigen with the competing monoclonal antibody M84, should be considered as the most useful because of cross-species and vaccination considerations. (author)

  13. Rapid and sensitive detection of redspotted grouper nervous necrosis virus (RGNNV) infection by aptamer-coat protein-aptamer sandwich enzyme-linked apta-sorbent assay (ELASA).

    Science.gov (United States)

    Zhou, L; Li, P; Ni, S; Yu, Y; Yang, M; Wei, S; Qin, Q

    2017-12-01

    Redspotted grouper nervous necrosis virus (RGNNV) is one of the most devastating pathogens in the aquaculture of the grouper, Epinephlus sp., worldwide. The early and rapid diagnosis of RGNNV is important for the prevention of RGNNV infection. In this study, an aptamer (A10)-based sandwich enzyme-linked apta-sorbent assay (ELASA) was developed for RGNNV diagnosis. This sandwich ELASA showed high specificity for the RGNNV coat protein (CP) and virions in virus-infected cells and tissues. At the optimized working concentration of 200 nM of aptamer, the ELASA could detect RGNNV in the lysates of as few as 4 × 10 3 RGNNV-infected GB cells. Incubation for 10 min was sufficient to produce accurate results. The sandwich ELASA was most stable at incubation temperatures of 4-25°C, but could still distinguish RGNNV-infected samples from the controls at 37°C. It could detect RGNNV infection in brain lysates diluted 1/10, with results consistent with those of reverse transcription PCR, although with 10% less sensitivity. The main equipment required includes dissection tools, a water bath, Pierce™ Streptavidin Coated Plates and a microplate reader. The sandwich ELASA has great potential utility for the rapid and sensitive diagnosis of RGNNV in its early stages by fish farmers. © 2017 John Wiley & Sons Ltd.

  14. Development and Application of a Double-Antigen Sandwich Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to Porcine Circovirus 2

    Science.gov (United States)

    Ge, Meng; Luo, Wei; Jiang, Daliang; Li, Runcheng; Zhao, Wenwei; Chen, Guoliang; Yang, Xingdong

    2012-01-01

    A double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) is described for detection of porcine circovirus 2 (PCV2) antibodies using the well-characterized recombinant PCV2 capsid protein. In a comparative test of 394 pig sera against an indirect immunofluorescence (IIF) test and a commercial ELISA kit (also based on the recombinant PCV2 capsid protein), the results showed that the diagnostic sensitivity, specificity, and accuracy of the assay were, respectively, 90.61, 94.02, and 91.62% compared with IIF and 94.38, 95.28, and 94.67% compared with the commercial ELISA kit. Assay of 12 PCV-free pigs over a 5-week period produced only PCV2-negative titers by all 3 methods. These results and the seroprofiles of 4 pig farms obtained by both the commercial ELISA kit and the double-antigen sandwich ELISA indicate that the sandwich ELISA is a reliable method for detection of antibodies to PCV2. Additionally, the method described here permits the use of undiluted test serum samples simultaneously loaded with horseradish peroxidase (HRP)-conjugated antigen into the test well, and the complete test procedure can be performed in less than 90 min. This double-antigen sandwich ELISA should be a useful tool to aid swine industry professionals in deciding the intervention strategies for the control of PCV2-associated diseases. PMID:22815145

  15. Assessment of a 27-kDa antigen in enzyme-linked immunosorbent assay for the diagnosis of fasciolosis in Vietnamese patients.

    Science.gov (United States)

    Nguyen, T G T; Le, T H; De, N V; Doan, T T; Dao, T H T; Vercruysse, J; Dorny, P

    2010-04-01

    Fasciolosis has emerged as an important zoonotic disease in many parts of the world. In recent years, an increasing number of human cases were reported in Vietnam. In this study, the 27-kDa component protein from the excretory/secretory production of adult Fasciola gigantica, purified by high performance liquid chromatography, was assessed in an enzyme-linked immunosorbent assay (ELISA) to detect antibodies against Fasciola spp. for diagnosis of human fasciolosis. The ELISA showed a high sensitivity (100%) and specificity (97.67%) when tested on patients with fasciolosis, other parasitic infections, cholangiocarcinoma and on healthy controls. The assay was applied for diagnosis on 143 patients in the Viet Duc-Hanoi hospital who presented with clinical signs of liver disease and lesions in their livers as shown by imaging techniques. Antibodies were found in 37 (25.9%) of these patients, of whom only 3 shed Fasciola eggs in their stools (2.1%). The excellent response to triclabendazole treatment of 37 sero-positive patients confirmed the diagnosis of fasciolosis. This study demonstrated the diagnostic potential for human fasciolosis of the 27-kDa antigen ELISA. Fasciolosis should be considered in the differential diagnosis of hepatic disease in Vietnam.

  16. Development of an enzyme-linked immunosorbent assay-based method for measuring galactosyltransferase activity using a synthetic glycopolymer acceptor substrate.

    Science.gov (United States)

    Oubihi, M; Kitajima, K; Kobayashi, K; Adachi, T; Aoki, N; Matsuda, T

    1998-03-15

    A lectin-assisted enzyme-linked immunosorbent assay (ELISA)-based method using a synthetic glycopolymer as an acceptor substrate was developed for measuring beta 1,4-galactosyltransferase (GalT) activity. A polyacrylamide derivative having a beta-linked N-acetylglucosamine (GlcNAc beta) moiety on each monomeric unit was synthesized chemically and immobilized on a polystyrene microtiter plate as an acceptor substrate for GalT. After the plate was incubated with bovine GalT, the enzyme reaction product, beta-linked Gal residue on the polyacrylamide-bound GlcNAc residue, was detected by using Ricinus communis agglutinin 1 (RCA1), rabbit anti-RCA1 antibody, and a peroxidase-labeled anti-rabbit IgG. The lowest GalT concentration detectable by this method was about 0.5 mU/ml, which is comparable to those by the previously reported ELISA-based assays. The unique property of the glycopolymer, PAP(GlcNAc beta), of binding noncovalently but tightly to the polystyrene microtiter plate allowed the use of this acceptor substrate for the GalT activity measurement even in the presence of 1% Triton CF-54 and X-100. Our system was successfully applied to assess GalT activity in milk of various mammals.

  17. A novel enzyme-linked immunosorbent assay for detection of Escherichia coli O157:H7 using immunomagnetic and beacon gold nanoparticles

    Science.gov (United States)

    2014-01-01

    This paper presents a functional nanoparticle-enhanced enzyme-linked immunosorbent assay (FNP-ELISA) for detection of enterohemorrhagic Escherichia coli (EHEC) O157:H7. Immunomagnetic nanoparticles (IMMPs) conjugated with monoclonal anti-O157:H7 antibody were used to capture E. coli O157:H7. Beacon gold nanoparticles (B-GNPs) coated with polyclonal anti-O157:H7 and biotin single-stranded DNA (B-DNA) were then subjective to immunoreaction with E. coli O157:H7, which was followed by streptavidin-horseradish peroxidase (Strep-HRP) conjugated with B-GNPs based on a biotin-avidin system. The solutions containing E. coli O157:H7, IMMPs, B-GNPs, and Strep-HRP were collected for detecting color change. The signal was significantly amplified with detection limits of 68 CFU mL-1 in PBS and 6.8 × 102 to 6.8 × 103 CFU mL-1 in the food samples. The FNP-ELISA method developed in this study was two orders of magnitude more sensitive than immunomagnetic separation ELISA (IMS-ELISA) and four orders of magnitude more sensitive than C-ELISA. The entire detection process of E. coli O157:H7 lasted only 3 h, and thus FNP-ELISA is considered as a time-saving method. PMID:24864164

  18. Development of a fluorescent enzyme-linked DNA aptamer-magnetic bead sandwich assay and portable fluorometer for sensitive and rapid leishmania detection in sandflies.

    Science.gov (United States)

    Bruno, John G; Richarte, Alicia M; Phillips, Taylor; Savage, Alissa A; Sivils, Jeffrey C; Greis, Alex; Mayo, Michael W

    2014-01-01

    A fluorescent peroxidase-linked DNA aptamer-magnetic bead sandwich assay is described which detects as little as 100 ng of soluble protein extracted from Leishmania major promastigotes with a high molarity chaotropic salt. Lessons learned during development of the assay are described and elucidate the pros and cons of using fluorescent dyes or nanoparticles and quantum dots versus a more consistent peroxidase-linked Amplex Ultra Red (AUR; similar to resazurin) fluorescence version of the assay. While all versions of the assays were highly sensitive, the AUR-based version exhibited lower variability between tests. We hypothesize that the AUR version of this assay is more consistent, especially at low analyte levels, because the fluorescent product of AUR is liberated into bulk solution and readily detectable while fluorophores attached to the reporter aptamer might occasionally be hidden behind magnetic beads near the detection limit. Conversely, fluorophores could be quenched by nearby beads or other proximal fluorophores on the high end of analyte concentration, if packed into a small area after magnetic collection when an enzyme-linked system is not used. A highly portable and rechargeable battery-operated fluorometer with on board computer and color touchscreen is also described which can be used for rapid (<1 h) and sensitive detection of Leishmania promastigote protein extracts (∼ 100 ng per sample) in buffer or sandfly homogenates for mapping of L. major parasite geographic distributions in wild sandfly populations.

  19. Anti-Toxoplasma gondii antibody detection in serum and urine samples by enzyme-linked immunosorbent assay in HIV-infected patients

    Directory of Open Access Journals (Sweden)

    Sayan Bhattacharyya

    2013-01-01

    Full Text Available Background: Toxoplasmosis is a common parasitic infection of man, and reactivation of latent disease in HIV-infected patients can cause fatal encephalitis. Diagnosis depends on demonstration of parasite-specific antibodies in serum. In HIV-infected patients, IgM is often undetectable, whereas IgG remains detectable in the majority. Urine sample is very easily available and has not been evaluated for immunodiagnosis of toxoplasmosis. Aim: The study was an effort to find whether urine sample can be used in place of serum for immunodiagnosis of toxoplasmosis. Materials and Methods: Enzyme-linked immunosorbent assay (ELISA was carried out in serum and urine samples collected from 100 HIV-infected patients to detect anti-toxoplasma IgG and IgM antibodies and whether positivity correlated with the CD4 T-cell counts of patients. Results: In this study, we observed that there was no significant difference in positivity of anti-toxoplasma IgM and IgG between serum and urine samples of HIV-infected patients by ELISA. There was a negative correlation between CD4 count and seropositivity. Conclusion: Urine sample can be satisfactorily used in place of serum for immunodiagnosis of toxoplasmosis.

  20. Comparison of Enzyme-Linked Immunosorbent Assay, Surface Plasmon Resonance and Biolayer Interferometry for Screening of Deoxynivalenol in Wheat and Wheat Dust

    Directory of Open Access Journals (Sweden)

    Melanie Sanders

    2016-04-01

    Full Text Available A sample preparation method was developed for the screening of deoxynivalenol (DON in wheat and wheat dust. Extraction was carried out with water and was successful due to the polar character of DON. For detection, an enzyme-linked immunosorbent assay (ELISA was compared to the sensor-based techniques of surface plasmon resonance (SPR and biolayer interferometry (BLI in terms of sensitivity, affinity and matrix effect. The matrix effects from wheat and wheat dust using SPR were too high to further use this screenings method. The preferred ELISA and BLI methods were validated according to the criteria established in Commission Regulation 519/2014/EC and Commission Decision 2002/657/EC. A small survey was executed on 16 wheat lots and their corresponding dust samples using the validated ELISA method. A linear correlation (r = 0.889 was found for the DON concentration in dust versus the DON concentration in wheat (LOD wheat: 233 μg/kg, LOD wheat dust: 458 μg/kg.

  1. Removal of Lipid from Serum Increases Coherence between Brucellosis Rapid Agglutination Test and Enzyme-linked Immunosorbent Assay in Bears in Alaska, USA.

    Science.gov (United States)

    Godfroid, Jacques; Beckmen, Kimberlee; Helena Nymo, Ingebjørg

    2016-10-01

    In cases of chronic Brucella spp. infection, results of the rose bengal plate test (RBPT) and indirect enzyme-linked immunosorbent assay (ELISA) should be coherent, as reported in controlled conditions in the literature. We compared RBPT and ELISA results in 58 Alaska grizzly bears ( Ursus arctos horribilis), eight Kodiak brown bears ( Ursus arctos middendorffi), and six Alaska Peninsula brown bears ( Ursus arctos gyas). Of the 72 bears tested, 42 (58%) were ELISA positive and 53 (73%) were RBPT positive. However, the coherence between the tests was only fair (K=0.37, SE=0.11), suggesting that either the serologic results were not compatible with Brucella spp. infection or that there was a technical problem with the tests. To address a potential technical problem, we performed a 30-min chloroform/centrifugation cleanup. Following cleanup, the ELISA identified 43 positives (59%) and the RBPT identified 47 (65%), and the coherence between the tests was much improved (K=0.80, SE=0.07). We recommend cleaning wildlife sera with a high lipid content before performing RBPT and performing RBPT and ELISA in parallel to assess coherence. Our results suggest that Alaskan brown bears have been exposed to Brucella spp.

  2. Enzyme-linked immunosorbent assay (ELISA) using a specific monoclonal antibody as a new tool to detect Sudan dyes and Para red

    International Nuclear Information System (INIS)

    Ju Chunmei; Tang Yong; Fan Huiying; Chen Jinding

    2008-01-01

    To set up an immunoassay-based method to detect Sudan dyes and Para red, we generated a monoclonal antibody (Mab) using a specially designed carboxyl derivative of Sudan I (CSD I) as the immunogen. CSD I was synthesized by azocoupling reaction using 2-naphthol and diazotised 4-aminobenzoic acid. The antibody was obtained from a hybridoma, which was derived from the fusion of the mouse myeloma SP2/0 cells and the splenocytes from the mice immunized with the CSD I-bovine serum albumin (BSA) conjugate. In addition, we showed that the Mab was highly specific for Sudan I, III and Para red. The limit of detection was approximately 0.01 ng mL -1 in phosphate-buffered saline (PBS) buffer and 0.5 ng g -1 in chilli tomato sauce. The recoveries of Sudan I, III and Para red for the chilli tomato sauce were from 84% to 99% and coefficients of variation were from 14.9% to 33.3%. Thus, the enzyme-linked immunosorbent assay (ELISA) method is a rapid and high throughput screening tool to detect Sudan dyes and Para red in food products

  3. An enzyme-linked immunoabsorbent assay for estimating red cell survival of transfused red cells-validation using CR-51 labeling

    International Nuclear Information System (INIS)

    Drew, H.; Kickler, T.; Smith, B.; LaFrance, N.

    1984-01-01

    The survival time of transfused red cells antigenically distinct from the recipient's red cells was determined using an indirect enzyme linked antiglobulin test. These results were then compared to those determined by Cr-51 labeling. Three patients with hypoproliferative anemias and one patient (2 studies) with traumatic hemolytic anemia caused by a prosthetic heart valve were studied. Survival times were performed by transfusing a 5cc aliquot of Cr-51 labeled cells along with the remaining unit. One hour post transfusion, a blood sample was drawn and used as the 100% value. Subsequent samples drawn over a 2-3 week period were then compared to the initial sample to determine percent survival for both methods. The ELISA method for measuring red cell survival in antigenically distinct cells is in close agreement with the Cr-51 method. Although CR-51 labeling is the accepted method for red cell survival determination the ELISA method can be used when radioisotopes are unavailable or contraindicated or when the decision to estimate red cell survival is made after transfusion

  4. Development and Validation of an Enzyme-Linked Immunosorbent Assay for the Detection of Binding Anti-Drug Antibodies against Interferon Beta

    Directory of Open Access Journals (Sweden)

    Kathleen Ingenhoven

    2017-07-01

    Full Text Available ObjectiveTo develop and validate a method for the detection of binding anti-drug antibodies (ADAs against interferon beta (IFN-β in human serum as part of a European initiative (ABIRISK aimed at the prediction and analysis of clinical relevance of anti-biopharmaceutical immunization to minimize the risk.MethodA two-tiered bridging enzyme-linked immunosorbent assay (ELISA format was selected and validated according to current recommendations. Screening assay: ADA in serum samples form complexes with immobilized IFN-β and biotinylated IFN-β, which are then detected using HRP labeled Streptavidin and TMB substrate. Confirmation assay: Screen “putative positive” samples are tested in the presence of excess drug (preincubation of sera with 0.3 µg/mL of soluble IFN-β and percentage of inhibition is calculated.ResultsThe assay is precise, and the sensitivity of the assay was confirmed to be 26 ng/mL using commercially available polyclonal rabbit antihuman IFN-β in human sera as the positive control.ConclusionAn ultrasensitive ELISA for IFN-β-binding ADA testing has been validated. This will form the basis to assess anti-biopharmaceutical immunization toward IFN-β with regards to its clinical relevance and may allow for the development of predictive tools, key aims within the ABIRISK consortium.

  5. Increased sensitivity of 3D-Well enzyme-linked immunosorbent assay (ELISA) for infectious disease detection using 3D-printing fabrication technology.

    Science.gov (United States)

    Singh, Harpal; Shimojima, Masayuki; Fukushi, Shuetsu; Le Van, An; Sugamata, Masami; Yang, Ming

    2015-01-01

    Enzyme-linked Immunosorbent Assay or ELISA -based diagnostics are considered the gold standard in the demonstration of various immunological reaction including in the measurement of antibody response to infectious diseases and to support pathogen identification with application potential in infectious disease outbreaks and individual patients' treatment and clinical care. The rapid prototyping of ELISA-based diagnostics using available 3D printing technologies provides an opportunity for a further exploration of this platform into immunodetection systems. In this study, a '3D-Well' was designed and fabricated using available 3D printing platforms to have an increased surface area of more than 4 times for protein-surface adsorption compared to those of 96-well plates. The ease and rapidity in designing-product development-feedback cycle offered through 3D printing platforms provided an opportunity for its rapid assessment, in which a chemical etching process was used to make the surface hydrophilic followed by validation through the diagnostic performance of ELISA for infectious disease without modifying current laboratory practices for ELISA. The higher sensitivity of the 3D-Well (3-folds higher) compared to the 96-well ELISA provides a potential for the expansion of this technology towards miniaturization platforms to reduce time, volume of reagents and samples needed for laboratory or field diagnosis of infectious diseases including applications in other disciplines.

  6. Synthesis of an oxytetracyline-tolidin-BSA immunogen and antibodies production of anti-oxytetracyline developed for oxytetracyline residue detection with enzyme-linked immunosorbent assays technique

    Directory of Open Access Journals (Sweden)

    Widiastuti R

    2013-06-01

    Full Text Available An oxytetracycline-tolidin-bovine serum albumin (OTC-tolidin-BSA-conjugate was synthezed as immunogen for producing specific antibodies in immunized rabbits that would be used as reagent for development of OTC residue detection with enzym-linked immunoassays technique. The immunogen was prepared through diazotization tolidin and subsequently reacted with OTC. The red purple immunogen of OTC-tolidin-BSA absorbed at wave lengths of 277 nm and 488 nm under UV screening absorbances and confirmation with the high performance liquid chromatography (HPLC showed the absence of peak at retention time of 3.46 minutes. Characaterized result with SDS-PAGE showed the molecular weight of the OTC-tolidin-BSA at 69.79 kDA. Subsequently, the immunogen was immunized into New Zealand rabbits in order to produce the polyclonal antibodies. The antibodies were purified using a protein A sepharose column. The OD optimum responses of 0.92 to 1.20 were obtained from the second fractionation at dilution of 1/1000 by titrating the antibodies and OTC-tolidin-BSA coating antigen at concentration of 10 µg/mL on several bleeding times.

  7. Comparative assessment of enzyme-linked immunosorbent assay and Western blot for the diagnosis of toxocariasis in patients with skin disorders.

    Science.gov (United States)

    Bellanger, A-P; Humbert, P; Gavignet, B; Deschaseaux, A D; Barisien, C; Roussel, S; Millon, L; Aubin, F; Piarroux, R

    2010-01-01

    Background The link between various chronic skin disorders and toxocariasis was previously demonstrated by case reports and several case-control studies. However, these previous studies were based only on the Toxocara canis excretory-secretory-enzyme-linked immunosorbent assay (TES-ELISA) serological technique, which is not specific due to cross-reactivity with parasites of the genera Anisakis or Ascaris. Immunoblot analysis is highly specific and can detect very low levels of Toxocara antibodies. Therefore, this technique may be useful in the identification of Toxocara infection in patients with chronic skin disorders. Objectives Because urticaria and pruritus/prurigo are skin conditions previously associated with toxocariasis, we carried out a prospective study using both TES-ELISA and Toxocara Western blot on 113 patients with either chronic urticaria (n = 84) or chronic pruritus (n = 29). Methods Patients were matched with controls according to gender, age and residence location (rural or urban area). Data were analysed using a Mantel-Haenszel chi(2) test. Results The proportion of positive TES-ELISA results was not significantly different for patients with chronic skin disorders (urticaria or pruritus/prurigo) from that of control subjects. However, the proportion of positive immunoblot results was significantly higher for patients with chronic urticaria than for control subjects (P = 0.009). Conclusions Our study demonstrates the need to perform Western blotting immunodiagnosis, whatever the TES-ELISA result, to improve diagnosis of human toxocariasis in patients with chronic urticaria caused by Toxocara infection.

  8. Novel biotechnological platform based on baculovirus occlusion bodies carrying Babesia bovis small antigenic peptides for the design of a diagnostic enzyme-linked immunosorbent assay (ELISA).

    Science.gov (United States)

    López, M G; Pallarés, H M; Alfonso, V; Carmona, S J; Farber, M; Taboga, O; Wilkowsky, S E

    2018-01-01

    Baculoviruses are large DNA virus of insects principally employed in recombinant protein expression. Its ability to form occlusion bodies (OBs), which are composed mainly of polyhedrin protein (POLH), makes them biotechnologically attractive, as these crystals (polyhedra) can incorporate foreign peptides and can be easily isolated. On the other hand, peptide microarrays allow rapid and inexpensive high-throughput serological screening of new candidates to be incorporated to OBs. To integrate these 2 biotechnological approaches, we worked on Babesia bovis, one of the causative agents of bovine babesiosis. Current molecular diagnosis of infection with B. bovis includes enzyme-linked immunosorbent assay (ELISA) techniques, which use merozoite lysate obtained from infected bovine erythrocytes. However, it is important to produce recombinant antigens that replace the use of crude antigens. Here, we describe a new biotechnological platform for the design of indirect ELISAs based on 5 antigenic peptides of 15 amino acid residues of B. bovis (ApBb), selected from a peptide microarray and expressed as a fusion to POLH. An Sf9POLH E44G packaging cell line infected with recombinant baculoviruses carrying POLH-ApBb fusions yielded higher levels of chimeric polyhedra, highlighting the advantage of a trans-contribution of a mutant copy of polyhedrin. Finally, the use of dissolved recombinant polyhedra as antigens was successful in an ELISA assay, as B. bovis-positive sera recognized the fusion POLH-ApBb. Thus, the use of this platform resulted in a promising alternative for molecular diagnosis of relevant infectious diseases.

  9. Relative efficiency of polymerase chain reaction and enzyme-linked immunosorbant assay in determination of viral etiology in congenital cataract in infants

    Directory of Open Access Journals (Sweden)

    Shyamala G

    2008-01-01

    Full Text Available Background: Perinatal viral infections of fetus are among the leading causes of congenital cataract and identifying the viral etiology is important. Objectives: To detect the presence of Rubella virus (RV, herpes simplex virus (HSV and cytomegalovirus (CMV in lens aspirate specimens obtained from patients with congenital cataract and relate the results with serology. Setting and Design: Prospective study carried out in tertiary care hospital. Materials and Methods: Fifty lens aspirates from 50 infants with congenital cataract were subjected to HSV, RV isolation and polymerase chain reaction (PCR for detection of HSV and CMV. Reverse transcription polymerase chain reaction (RT-PCR was applied for RV detection. Peripheral blood specimens were screened for anti-HSV, RV and CMV antibodies by enzyme-linked immunosorbant assay (ELISA. Results: Rubella virus was detected in nine (18% lens aspirates, by nRT-PCR which includes six positive by culture. HSV-2 DNA was detected in nine other lens aspirates, while CMV was not detected by PCR. Serological results did not correlate with the presence of viruses in the lens aspirates. This is the first report of detection of HSV-2 DNA in cases of congenital cataract. Conclusions: Cytomegalovirus may not be playing a significant role in causation of congenital cataract. The role of serology in identifying causative viral infection for congenital cataract needs to be re-evaluated.

  10. Simple Identification of Human Taenia Species by Multiplex Loop-Mediated Isothermal Amplification in Combination with Dot Enzyme-Linked Immunosorbent Assay.

    Science.gov (United States)

    Nkouawa, Agathe; Sako, Yasuhito; Okamoto, Munehiro; Ito, Akira

    2016-06-01

    For differential detection of Taenia solium, Taenia saginata, and Taenia asiatica, loop-mediated isothermal amplification (LAMP) assay targeting the cytochrome c oxidase subunit 1 gene has been recently developed and shown to be sensitive, specific, and effective. However, to achieve differential identification, one specimen requires three reaction mixtures containing a primer set of each Taenia species separately, which is complex and time consuming and increases the risk of cross-contamination. In this study, we developed a simple differential identification of human Taenia species using multiplex LAMP (mLAMP) in combination with dot enzyme-linked immunosorbent assay (dot-ELISA). Forward inner primers of T. solium, T. saginata, and T. asiatica labeled with fluorescein isothiocyanate (FITC), digoxigenin (DIG), and tetramethylrhodamine (TAMRA), respectively, and biotin-labeled backward inner primers were used in mLAMP. The mLAMP assay succeeded in specific amplification of each respective target gene in a single tube. Furthermore, the mLAMP product from each species was easily distinguished by dot-ELISA with an antibody specific for FITC, DIG, or TAMRA. The mLAMP assay in combination with dot-ELISA will make identification of human Taenia species simpler, easier, and more practical. © The American Society of Tropical Medicine and Hygiene.

  11. Establishment of the enzyme-linked immunosorbent assay system to detect the amino terminal secretory form of rat Erc/Mesothelin.

    Science.gov (United States)

    Nakaishi, Masayuki; Kajino, Kazunori; Ikesue, Masahiro; Hagiwara, Yoshiaki; Kuwahara, Maki; Mitani, Hiroaki; Horikoshi-Sakuraba, Yuko; Segawa, Tatsuya; Kon, Shigeyuki; Maeda, Masahiro; Wang, Tegexibaiyin; Abe, Masaaki; Yokoyama, Masayoshi; Hino, Okio

    2007-05-01

    By representational difference analysis, we previously identified the rat Erc (Expressed in renal carcinoma) gene that was more abundantly expressed in the renal carcinoma tissues of Eker rats than in the rat normal kidney. In this study, we raised antibodies against the amino-terminal portion of the rat Erc, and demonstrated the existence of a approximately 30-kDa secretory form in the supernatant of cultured cells derived from rat renal carcinoma. The enzyme-linked immunosorbent assay (ELISA) system using these antibodies detected high concentrations of this form in the sera of Eker rats bearing renal carcinomas, and in the sera of rats transplanted with mesothelioma cells. Mesothelin, a human homolog of the rat Erc, was recently reported to be a serum marker of malignant mesothelioma. The prognosis of mesothelioma is poor and there is no effective treatment at present. There are several rat model systems of mesothelioma that may be promising tools in the development of an antimesothelioma treatment. We hope our ELISA to detect the soluble form of rat Erc/Mesothelin is useful in the rat model system to exploit the antimesothelioma therapy to be used in human cases.

  12. In-house validation and quality control of commercial enzyme-linked immunosorbnet assays for screening of nitrofuran metabolites in food of animal origin

    Directory of Open Access Journals (Sweden)

    Dimitrieska-Stojkovic Elizabeta

    2012-01-01

    Full Text Available Application of nitrofuran antimicrobials at food production animals was prohibited by Commission Regulation 2003/181/EC because of their potential carcinogenic and mutagenic effects on humans. Main protein-bound metabolites of nitofurans are 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ, 1-aminohydantoin (AHD, semicarbazide (SEM and 3-amino-2-oxazolidinone (AOZ. Since then numerous costly liquid chromatography with tandem mass spectrometry (LC/MS/MS methods have been developed for screening and confirmation of nitrofuran metabolites in line with the EU requirements for performing official controls. As an inexpensive and less time consuming alternative, enzyme-immunoassay methods were developed for screening of the respective compounds. In this study validation and evaluation of four commercial enzyme-linked immunosorbent assay (ELISA has been performed. According to the requirements of Commission Decision 2002/657/EC, different performance characteristics (specificity, detection capability, precision for various matrices (liver, eggs, honey have been determined for each kit. The validation study has confirmed that the methods studied possess suitable characteristics: detectionlimits between 0.126 and 0.240 μg/kg, detection capabilities ≤1.0 μg/kg and the inter-day precision in the range from 16.20% to 22.11 %. The validation study was finalized by participation in FAPAS Proficiency testing scheme in 2011, and the obtained results have confirmed the capability of applied methods for unambiguous discrimination between negative and positive sample.

  13. Development of a Nucleoprotein-Based Enzyme-Linked Immunosorbent Assay Using a Synthetic Peptide Antigen for Detection of Avian Metapneumovirus Antibodies in Turkey Sera

    Science.gov (United States)

    Alvarez, Rene; Njenga, M. Kariuki; Scott, Melissa; Seal, Bruce S.

    2004-01-01

    Avian metapneumoviruses (aMPV) cause an upper respiratory tract disease with low mortality but high morbidity, primarily in commercial turkeys, that can be exacerbated by secondary infections. There are three types of aMPV, of which type C is found only in the United States. The aMPV nucleoprotein (N) amino acid sequences of serotypes A, B, and C were aligned for comparative analysis. On the basis of the predicted antigenicity of consensus sequences, five aMPV-specific N peptides were synthesized for development of a peptide antigen enzyme-linked immunosorbent assay (aMPV N peptide-based ELISA) to detect aMPV-specific antibodies among turkeys. Sera from naturally and experimentally infected turkeys were used to demonstrate the presence of antibodies reactive to the chemically synthesized aMPV N peptides. Subsequently, aMPV N peptide 1, which had the sequence 10-DLSYKHAILKESQYTIKRDV-29, with variations at only three amino acids among aMPV serotypes, was evaluated as a universal aMPV ELISA antigen. Data obtained with the peptide-based ELISA correlated positively with total aMPV viral antigen-based ELISAs, and the peptide ELISA provided higher optical density readings. The results indicated that aMPV N peptide 1 can be used as a universal ELISA antigen to detect antibodies for all aMPV serotypes. PMID:15013970

  14. Field estimation of the flock-level diagnostic specificity of an enzyme-linked immunosorbent assay for Avian metapneumovirus antibodies in turkeys.

    Science.gov (United States)

    Muñoz-Zanzi, Claudia; Trampel, Darrell; Hanson, Tim; Harrison, Kristen; Goyal, Sagar; Cortinas, Roberto; Lauer, Dale

    2009-03-01

    Routine serologic testing for Avian metapneumovirus (AMPV) infection of turkey flocks at slaughter is currently being used to monitor changes in the occurrence of AMPV infection in endemic areas and can also be used to detect the emergence of infection in currently unaffected areas. Because of the costs associated with false-positive results, particularly in areas that are free of AMPV infection, there is a need to obtain improved estimates of flock-level specificity (SP). The objective of this study was to estimate flock-level SP of a program to monitor AMPV infection in turkey flocks at processing using a standard enzyme-linked immunosorbent assay (ELISA). A study was carried out in which 37 AMPV-free flocks from 7 Midwest operations were followed serologically. Six percent, 3%, and 0.2% of total samples tested AMPV positive at 8 weeks, 12 weeks, and at processing, respectively. Overall, flock-level SP increased as the cutoff increased and as age increased. Flock-level SP at processing was 97%, if a cutoff of 1 was used (the flock was classified as positive if at least 1 sample tested positive), and 100%, if any other cutoff was used. Administration of antibiotics (P = 0.02) and vaccination for Bordetella avium (P = 0.08) were positively associated with the probability of (false) positive test results. These findings suggest possible cross-reactions with other infections and highlight the need to consider variable diagnostic performance depending on farm conditions.

  15. The External Quality Assurance Oversight Laboratory (EQAPOL) proficiency program for IFN-gamma enzyme-linked immunospot (IFN-γ ELISpot) assay.

    Science.gov (United States)

    Sanchez, Ana M; Rountree, Wes; Berrong, Mark; Garcia, Ambrosia; Schuetz, Alexandra; Cox, Josephine; Frahm, Nicole; Manak, Mark; Sarzotti-Kelsoe, Marcella; D'Souza, M Patricia; Denny, Thomas; Ferrari, Guido

    2014-07-01

    The interferon-gamma enzyme-linked immunospot (IFN-γ ELISpot) assay has been developed and used as an end-point assay in clinical trials for infectious diseases and cancer to detect the magnitude of antigen-specific immune responses. The ability to compare data generated by different laboratories across organizations is pivotal to understand the relative potency of different therapeutic and vaccine strategies. We developed an external proficiency program for the IFN-γ ELISpot assay that evaluates laboratory performance based on five parameters: timeliness for data reporting; ability to handle cellular samples; detection of background (non-specific) responses; accuracy to consensus of the results; and precision of the measurements. Points are awarded for each criterion, and the sum of the points is used to determine a numeric and adjectival performance rating. Importantly, the evaluation of the accuracy to the consensus mean for the detection of antigen-specific responses using laboratory-specific procedures informs each laboratory and its sponsor on the degree of concordance of its results with those obtained by other laboratories. This study will ultimately provide the scientific community with information on how to organize and implement an external proficiency program to evaluate longitudinally the performance of the participating laboratories and, therefore, fulfill the requirements of the GCLP guidelines for laboratories performing end-point IFN-γ ELISpot assay for clinical trials. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. A single serum dilution enzyme-linked immunosorbent assay for determining anti-human papillomavirus (HPV) antibody titres in humans immunised with prophylactic HPV vaccines.

    Science.gov (United States)

    Jin, Yingji; Kim, Hyoung Jin; Yim, Ga Won; Kim, Young Tae; Chang, Don Yong; Kim, Hong-Jin

    2012-07-01

    Two types of prophylactic human papillomavirus (HPV) vaccines are currently available. However, there is no simple monitoring system for assessing acquired immunity that can cope simultaneously with large numbers of serum samples. Approximately 30% of women with normal cytology are known to be seropositive for HPV types 16 and 18 because of the high prevalence of these HPV types. Therefore, to be useful the monitoring system has to discriminate clearly between vaccine recipients and other serology groups. However, there has never been any focus on developing a method to satisfy this condition. In this study, we developed a high-throughput single-serum-dilution enzyme-linked immunoassay (ELISA) system for determining anti-HPV antibody titres following vaccination. We optimised the conditions for each ELISA step to increase its accuracy and precision and to avoid the high background of non-specific reactions that is a major problem for serology assays. The new ELISA system has superior linearity, accuracy and reproducibility. Moreover, it clearly discriminated between antibody levels in vaccine recipients and those in other serology groups such as individuals with normal cervical cytology and those with cervical cancer. Therefore, this single-serum-dilution ELISA should be very useful for assessing the acquired immunity of HPV vaccine recipients. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Development of an enzyme-linked immunosorbent assay to identify host-feeding preferences of Phlebotomus species (Diptera: Psychodidae) in endemic foci of visceral leishmaniasis in Nepal.

    Science.gov (United States)

    Burniston, Ian; Roy, Lalita; Picado, Albert; Das, Murari; Rijal, Suman; Rogers, Matthew; Coosemans, Marc; Boelaert, Marleen; Davies, Clive; Cameron, Mary

    2010-09-01

    Anthroponotic visceral leishmaniasis, transmitted by Phlebotomus argentipes Annandale & Brunetti (Diptera: Psychodidae) sand flies, is regarded as a major problem of public health importance in the Indian subcontinent. Understanding the feeding behavior of the vector can be used to investigate changes in human-vector contact during intervention programs. An enzyme-linked immunosorbent assay (ELISA) was modified to make it suitable to identify the origin of P. argentipes and Phlebotomus papatasi Scopoli (Diptera: Psychodidae) blood meals. The sensitivity and specificity of the precipitin ring test and ELISA were compared, as well as the stability of the tests across different stages of blood meal digestion. The ELISA was more sensitive and specific than the precipitin test for identifying the sources of blood meals. When using the ELISA method with a plate reader, it was possible to obtain 100% sensitivity and specificity. When comparing the techniques across digestion stages, it was found that there was a drop in sensitivity, 48 and 72 h postblood meal for precipitin and visually read ELISA, respectively. However, the sensitivity of the ELISA using a plate reader was not altered by the digestion time. The feeding habits of P. argentipes and P. papatasi from the Terai region of Nepal, determined by the ELISA developed, showed P. papatasi to be highly anthropophilic, and P. argentipes appeared to feed both on humans and animals, in particular bovines.

  18. Quantitative Analysis of Free 15-F2t-Isoprostane from Plasma of Obstructive Sleep Apnea Patients Using Enzyme Linked Immunosorbe

    Directory of Open Access Journals (Sweden)

    Bertha Rusdi

    2012-03-01

    Full Text Available 15-F2t-isoprostane is a biomarker in assessment of oxidative stress status that due to its relatively low concentration in biological fluid and also has many isomers, the 15-F2t-isoprostane sample need to be extracted prior to the quantifying processes. Extraction techniques commonly used to extract 15-F2t-isoprostane are solid phase extraction (SPE and immunoaffinity extraction. Improvements to the SPE and immunoaffinity extraction techniques had been conducted, and the recovery results was then compared. The quantification of 15-F2t-isoprostane then was conducted using Enzyme Linked Immunosorbent Assay (ELISA method. Then followed by the examination of the plasma recovery results. Extraction technique which had the highest recovery then was used to quantify 15-F2t-isoprostane from plasma of Obstructive Sleep Apnea (OSA patients. Immunoaffinity extraction technique has a good recovery result. OSA patients have the tendency to have high 15-F2t-isoprostane concentrations in the plasma, therefore have a potential risk to get diseases related to the biological activities of 15-F2t-isoprostane, such as arteriosclerosis.

  19. Determination of the folate content in cladodes of nopal (Opuntia ficus indica) by microbiological assay utilizing Lactobacillus casei (ATCC 7469) and enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Ortiz-Escobar, Tania Breshkovskaya; Valverde-González, Maria Elena; Paredes-López, Octavio

    2010-05-26

    Prickly pear cactus has been an important food source in Mexico since ancient times due to its economical and ecological benefits and potential nutraceutical value. Nevertheless, studies on the nutritional aspects and health benefits have been scarce. The purpose of this study was to assess, apparently for the first time, the folate contents of cladodes of nopal by a microbiological assay, using Lactobacillus casei (ATCC 7469) in extracts that were enzymatically treated to release the bound vitamin, employing single, dual, and trienzymatic procedures, and using the enzyme-linked immunosorbent assay (ELISA). We used Opuntia cladodes of different length sizes. The microbiological assay showed some differences among enzyme treatments and sizes of nopal; the trienzyme treatment (alpha-amylase-protease-conjugase) was more efficient in determining the folate content in nopal, giving 5.0 ng/g in the small size cladodes at 54 h of testing time, while ELISA showed no significant differences in the folate content among sizes of cladodes (5.5-5.62 ng/g at 0 min testing time). Both techniques may be used for the assessment of folate content in cladodes, but ELISA is more rapid and reliable.

  20. A polymerase chain reaction and enzyme linked immunosorbent assay based approach for diagnosis and differentiation between vaccinated and infected cattle with Mycobacterium bovis

    Science.gov (United States)

    Sabry, Mohamed; Elkerdasy, Ahmed

    2014-01-01

    Background: In most African and Arabic countries tuberculosis (TB) causes great economic losses in bovine species and constitutes serious zoonotic problem. As the traditional diagnostic method delay the research because of low sensitivity and specificity, a rapid method of diagnosis is of outmost importance. Aim: The study was designed to evaluate the two rapid diagnostic methods of TB in cattle, further to differentiate between infected and bacillus Calmette-Guerin (BCG) vaccinated animals. Materials and Methods: Intradermal tuberculin test was applied to 300 cattle. Of these cattle, 15 cattle were vaccinated from cattle negative to tuberculin test with BCG. Blood samples were taken for lymphocyte separation to apply polymerase chain reaction (PCR) upon and for serum preparation for the enzyme-linked immunosorbent assay (ELISA) application, this blood collected from 65 cattle classified into three groups, viz. positive tuberculin test (35 animals), negative tuberculin test (15 animals), and vaccinated cow with BCG (15 animals). From blood samples lymphocytes were separated and the isolated lymphocytes were subjected to PCR and serum for ELISA application. Blood samples, specimens from lymph nodes and specific tissues were taken for PCR and for cultivation and isolation of Mycobacterium bovis. Results and Conclusions: The results of this study revealed that PCR can be used as rapid efficient and accurate diagnostic test in detection of ruminant TB. Moreover, cattle's ELISA reading showed higher sensitivity in positive tuberculin animals. However, the differentiations between vaccinated and infected animals not clear by using a single antigen only. PMID:24741280

  1. Development of an automated wax-printed paper-based lateral flow device for alpha-fetoprotein enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Preechakasedkit, Pattarachaya; Siangproh, Weena; Khongchareonporn, Nanthika; Ngamrojanavanich, Nattaya; Chailapakul, Orawon

    2018-04-15

    In this study, a novel wax-printed paper-based lateral flow device has been developed as an alternative approach for an automated and one-step enzyme-linked immunosorbent assay (ELISA). The design pattern consisted of a non-delayed channel, a wax-delayed channel, a test zone and a control zone. This system was easily fabricated on a nitrocellulose membrane using a wax-printing method and then baked in an oven at 100°C for 1min. The four barriers of the wax-delayed channel could delay the flow time for 11s compared to the flow time of the non-delayed channel. To use the device under optimal conditions, alpha-fetoprotein (AFP) was detected at a limit of detection of 1ngmL -1 and assessed with the naked eye within 10min. A colorimetric intensity was also measured using a smart phone and computer software at a linear range of 0.1-100ngmL -1 with a good correlation. Furthermore, the proposed device was successfully applied to detect AFP in human serum. Therefore, the wax-printing demonstrates a user-friendly, easy and quick method for the fabrication of the device, which could be used as a one-step, portable, disposable, low-cost, simple, instrument-free and point-of-care device for the automated ELISA. Copyright © 2017. Published by Elsevier B.V.

  2. Prospective evaluation of nonstructural 1 enzyme-linked immunosorbent assay and rapid immunochromatographic tests to detect dengue virus in patients with acute febrile illness.

    Science.gov (United States)

    Najioullah, Fatiha; Combet, Emilie; Paturel, Laure; Martial, Jenny; Koulmann, Laurence; Thomas, Laurent; Hatchuel, Yves; Cabié, André; Cesaire, Raymond

    2011-02-01

    We prospectively evaluated the Bio-Rad nonstructural 1 (NS1) enzyme-linked immunosorbent assay (ELISA) and lateral flow immunochromatographic assay (LFIA) in comparison to an in-place reverse transcription-polymerase chain reaction for dengue diagnosis. Among 537 consecutive samples from patients with acute febrile disease, 264 (49.2%) tested positive in reverse transcription-polymerase chain reaction (RT-PCR), 156 (29.1%) in NS1-antigen (Ag) ELISA, and 125 (23.3%) in NS1-Ag LFIA. Compared to the RT-PCR status, the specificity was 100% for the NS1-Ag ELISA and LFIA, but their respective sensitivities were 61.2% [95% confidence interval (CI), 55.2-67.2] and 49.4% (95% CI, 43.2-55.6), with nadirs of 37.9% and 24.1% on day 6 of illness. The NS1-Ag ELISA and LFIA were positive, respectively, for 48.0% and 40.7% of the secondary infections versus 85.0% and 66.7% of the primary infections. For patients LFIA reached respective sensitivities of 100% and 90.5%. Reports of results of dengue NS1-Ag assays should specify that negativity does not preclude DENV infection, and require further investigations in the case of severe disease. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Evaluation of two Neospora caninum recombinant antigens for use in an enzyme-linked immunosorbent assay for the diagnosis of bovine neosporosis.

    Science.gov (United States)

    Lally, N C; Jenkins, M C; Dubey, J P

    1996-01-01

    Neospora caninum is a recently described apicomplexan parasite which causes paralysis and death in dogs. Neospora parasites also cause abortion and neonatal morbidity in cattle, sheep, goats, and horses, and neosporosis is emerging as an important cause of bovine abortion worldwide. The purpose of this study was to identify N. caninum cDNA clones encoding antigens that would be useful for the immunodiagnosis of bovine neosporosis. Two N. caninum tachyzoite cDNA clones expressing antigens that were recognized by serum from naturally and experimentally infected cattle were identified. The DNA sequences of these clones were determined, and the inserts were subcloned into the plasmid expression vector pTrcHisB. Both recombinant antigens, expressed as fusion proteins with a His6 tag, were purified on a nickel-chelating affinity column and evaluated in separate enzyme-linked immunosorbent assays (ELISAs). Both recombinant antigen ELISAs were capable of distinguishing between sera from Neospora-infected cows and sera from uninfected control cows. Furthermore, both assays were able to detect an antibody response in animals that were experimentally inoculated with N. caninum. Neither antigen showed evidence of cross-reactivity with serum from animals inoculated with the closely related parasites Toxoplasma gondii, Sarcocystis cruzi, Sarcocystis hominis, and Sarcocystis hirsuta. PMID:8705668

  4. Evaluation of enzyme-linked immunosorbent assays performed on milk and serum samples for detection of neosporosis and leukosis in lactating dairy cows.

    Science.gov (United States)

    Walsh, Robert B; Kelton, David F; Hietala, Sharon K; Duffield, Todd F

    2013-04-01

    Serum and milk samples from 1229 cows on 22 Ontario dairy farms were individually tested for antibodies specific for bovine leukosis virus (BLV) and Neospora caninum by enzyme-linked immunosorbent assay (ELISA). Antibodies against BLV were present in 361 serum samples (29.4%) and 369 milk samples (30.0%). Comparing the 2 tests, agreement was almost perfect (k = 0.86; 95% CI = 0.83 to 0.90) and the proportions of samples positive were not significantly different (P = 0.56). Both tests identified the same 3 herds free of bovine leukosis virus. Antibodies against N. caninum were detected in 138 serum samples (11.2%), and 111 milk samples (9.0%). Agreement between the 2 tests was moderate (k = 0.52; 95% CI = 0.43 to 0.59). Four herds were free of neosporosis by the serum test, while 10 herds were negative by the milk test. The ELISA on milk samples facilitates sample collection to classify herds free of BLV; the milk N. caninum ELISA was less reliable in predicting herd-level infection.

  5. Commercial enzyme-linked immunosorbent assay versus polymerase chain reaction for the diagnosis of chronic Chagas disease: a systematic review and meta-analysis

    Science.gov (United States)

    do Brasil, Pedro Emmanuel Alvarenga Americano; Castro, Rodolfo; de Castro, Liane

    2016-01-01

    Chronic Chagas disease diagnosis relies on laboratory tests due to its clinical characteristics. The aim of this research was to review commercial enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) diagnostic test performance. Performance of commercial ELISA or PCR for the diagnosis of chronic Chagas disease were systematically searched in PubMed, Scopus, Embase, ISI Web, and LILACS through the bibliography from 1980-2014 and by contact with the manufacturers. The risk of bias was assessed with QUADAS-2. Heterogeneity was estimated with the I2 statistic. Accuracies provided by the manufacturers usually overestimate the accuracy provided by academia. The risk of bias is high in most tests and in most QUADAS dimensions. Heterogeneity is high in either sensitivity, specificity, or both. The evidence regarding commercial ELISA and ELISA-rec sensitivity and specificity indicates that there is overestimation. The current recommendation to use two simultaneous serological tests can be supported by the risk of bias analysis and the amount of heterogeneity but not by the observed accuracies. The usefulness of PCR tests are debatable and health care providers should not order them on a routine basis. PCR may be used in selected cases due to its potential to detect seronegative subjects. PMID:26814640

  6. [Evaluation of usefulness of commercial recomwell Campylobacter enzyme--linked immunosorbent assays for routine serodiagnosis of Campylobacter jejuni and Campylobacter coli infections].

    Science.gov (United States)

    Rokosz, Natalia; Rastawicki, Waldemar; Jagielski, Marek

    2008-01-01

    The commercially available enzyme-linked immunosorbent assays (ELISA recomWell Campylobacter) from Mikrogen was evaluated for the diagnosis of Campylobacter jejuni and Campylobacter coli infections. Serum samples from 20 healthy controls, 44 persons with symptoms of primary Campylobacter infection and 24 serum samples from patients with Yersinia enterocolitica or Salmonella infections were tested. This ELISA assay detects IgA and IgG antibodies against three recombinant antigens of the Campylobacter jejuni and Campylobacter coli: OMP 18 (18 kDa), PEB4 (31 kDa) and P39 (39 kDa). The healthy controls showed significantly lower antibody titers in all two immunoglobulin classes. The IgA antibodies were diagnosed only in 2 (18.2%) serum samples obtained from patients with bacteriologically confirmed campylobacteriosis. The presence of IgG antibodies was confirmed in 82% of serum samples. Furthermore, we showed that 66.7% of the 33 serum samples obtained from the patients suspected for campylobacteriosis not confirmed by isolation, were positive for IgG and 15.2% for IgA antibodies. We observed also not specific reactions in ELISA recom Well Campylobacter with sera obtained form patients with yersiniosis and salmonelosis. This study demonstrates the usefulness of commercially available assay for the routine diagnosis of Campylobacter infection but with some limitations.

  7. Enzyme-Linked Immunosorbent Assay Using a Virus Type-Specific Peptide Based on a Subdomain of Envelope Protein Erns for Serologic Diagnosis of Pestivirus Infections in Swine

    Science.gov (United States)

    Langedijk, J. P. M.; Middel, W. G. J.; Meloen, R. H.; Kramps, J. A.; de Smit, J. A.

    2001-01-01

    Peptides deduced from the C-terminal end (residues 191 to 227) of pestivirus envelope protein Erns were used to develop enzyme-linked immunosorbent assays (ELISAs) to measure specifically antibodies against different types of pestiviruses. The choice of the peptide was based on the modular structure of the Erns protein, and the peptide was selected for its probable independent folding and good exposure, which would make it a good candidate for an antigenic peptide to be used in a diagnostic test. A solid-phase peptide ELISA which was cross-reactive for several types of pestivirus antibodies and which can be used for the general detection of pestivirus antibodies was developed. To identify type-specific pestivirus antibodies, a liquid-phase peptide ELISA, with a labeled, specific classical swine fever virus (CSFV) peptide and an unlabeled bovine viral diarrhea virus peptide to block cross-reactivity, was developed. Specificity and sensitivity of the liquid-phase peptide ELISA for CSFV were 98 and 100%, respectively. Because the peptide is a fragment of the Erns protein, it can be used to differentiate between infected and vaccinated animals when a vaccine based on the E2 protein, which is another pestivirus envelope protein, is used. PMID:11230402

  8. Expression of sheep pathogen Babesia sp. Xinjiang rhoptry-associated protein 1 and evaluation of its diagnostic potential by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Niu, Qingli; Liu, Zhijie; Yang, Jifei; Yu, Peifa; Pan, Yuping; Zhai, Bintao; Luo, Jianxun; Guan, Guiquan; Yin, Hong

    2016-12-01

    Ovine babesiosis is one of the most important tick-borne haemoparasitic diseases of small ruminants. The ovine parasite Babesia sp. Xinjiang is widespread in China. In this study, recombinant full-length XJrRAP-1aα2 (rhoptry-associated protein 1aα2) and C-terminal XJrRAP-1aα2 CT of Babesia sp. Xinjiang were expressed and used to evaluate their diagnostic potential for Babesia sp. Xinjiang infections by indirect enzyme-linked immunosorbent assay (ELISA). Purified XJrRAP-1aα2 was tested for reactivity with sera from animals experimentally infected with Babesia sp. Xinjiang and other haemoparasites using Western blotting and ELISA. The results showed no cross-reactivities between XJrRAP-1aα2 CT and sera from animals infected by other pathogens. High level of antibodies against RAP-1a usually lasted 10 weeks post-infection (wpi). A total of 3690 serum samples from small ruminants in 23 provinces located in 59 different regions of China were tested by ELISA. The results indicated that the average positive rate was 30·43%, and the infections were found in all of the investigated provinces. This is the first report on the expression and potential use of a recombinant XJrRAP-1aα2 CT antigen for the development of serological assays for the diagnosis of ovine babesiosis, caused by Babesia sp. Xinjiang.

  9. Enzyme-linked immunosorbent assay and polymerase chain reaction performance using Mexican and Guatemalan discrete typing unit I strains of Trypanosoma cruzi.

    Science.gov (United States)

    Ballinas-Verdugo, Martha; Reyes, Pedro Antonio; Mejia-Dominguez, Ana; López, Ruth; Matta, Vivian; Monteón, Victor M

    2011-12-01

    Thirteen Trypanosoma cruzi isolates from different geographic regions of Mexico and Guatemala belonging to discrete typing unit (DTU) I and a reference CL-Brener (DTU VI) strain were used to perform enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). A panel of 57 Mexican serum samples of patients with chronic chagasic cardiopathy and asymptomatic infected subjects (blood bank donors) were used in this study. DNA from the above 14 T. cruzi strains were extracted and analyzed by PCR using different sets of primers designed from minicircle and satellite T. cruzi DNA. The chronic chagasic cardiopathy serum samples were easily recognized with ELISA regardless of the source of antigenic extract used, even with the CL-Brener TcVI, but positive serum samples from blood bank donors in some cases were not recognized by some Mexican antigenic extracts. On the other hand, PCR showed an excellent performance despite the set of primers used, since all Mexican and Guatemalan T. cruzi strains were correctly amplified. In general terms, Mexican, Guatemalan, and CL-Brener T. cruzi strains are equally good sources of antigen when using the ELISA test to detect Mexican serum samples. However, there are some strains with poor performance. The DTU I strains are easily detected using either kinetoplast or satellite DNA target designed from DTU VI strains.

  10. Enzyme-Linked Immunospot Assay as a Complementary Method to Assess and Monitor Cytomegalovirus Infection in Kidney Transplant Recipients on Pre-emptive Antiviral Therapy: A Single-Center Experience.

    Science.gov (United States)

    Favi, E; Santangelo, R; Iesari, S; Morandi, M; Marcovecchio, G E; Trecarichi, E M; Salerno, M P; Ferraresso, M; Citterio, F; Romagnoli, J

    2017-10-01

    Cytomegalovirus (CMV) disease represents a major cause of post-transplantation morbidity and mortality. To estimate the risk of infection and monitor response to antiviral therapy, current guidelines suggest combination of viral load monitoring with direct assessment of CMV-specific immune response. We used enzyme-linked immunospot (ELISpot) for the evaluation of CMV-specific T-cell response in kidney transplant recipients with CMV viremia and investigated how information gained could help manage CMV infection. Seventeen patients on pre-emptive antiviral therapy and CMV quantitative polymerase chain reaction (qPCR) ≥500 copies/mL (first episode after transplantation) were assessed using ELISpot and divided into Weak (9 patients with baseline ELISpot antiviral therapy were prospectively recorded and compared between groups at 1, 2, and 24 months of follow-up. Demographic and transplant characteristics of Weak and Strong Responders were similar. No episodes of CMV disease were observed. Weak Responders were more likely to experience CMV syndrome (56% vs 36.5%) and late virus reactivation (56% vs 25%) than Strong Responders. Weak Responders showed higher baseline median viral loads (19,700 vs 9265 copies/mL) and needed antiviral therapy for longer (179 vs 59.5 days). T-cell response showed 2 main patterns: early and delayed. ELISpot provides prognostic information about infection severity, risk of late reactivation, and response to therapy. Randomized trials, evaluating the need for antiviral therapy in kidney transplant recipients with asymptomatic infection and effective virus-specific T-cell immune response, are warranted. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Application of the Ceditest FMDV type O and FMDV-NS enzyme-linked immunosorbent assays for detection of antibodies against Foot-and-mouth disease virus in selected livestock and wildlife species in Uganda

    DEFF Research Database (Denmark)

    Ayebazibwe, Chrisostom; Mwiine, Frank Norbert; Balinda, Sheila Nina

    2012-01-01

    Diagnosis and control of Foot-and-mouth disease virus (FMDV) requires rapid and sensitive diagnostic tests. Two antibody enzyme-linked immunosorbent assay (ELISA) kits, Ceditest FMDV-NS for the detection of antibodies against the nonstructural proteins of all FMDV serotypes and Ceditest FMDV type...

  12. Enzyme-linked immunosorbent assay using a virus type-specific peptide based on a subdomain of envelope protein e(rns) for serologic diagnosis of pestivirus infections in swine

    NARCIS (Netherlands)

    Langedijk, J.P.; Middel, W.G.; Meloen, R.H.; Kramps, J.A.; Smit, de J.A.

    2001-01-01

    Peptides deduced from the C-terminal end (residues 191 to 227) of pestivirus envelope protein Erns were used to develop enzyme-linked immunosorbent assays (ELISAs) to measure specifically antibodies against different types of pestiviruses. The choice of the peptide was based on the modular structure

  13. Direct and indirect climatic drivers of biotic interactions: ice-cover and carbon runoff shaping Arctic char Salvelinus alpinus and brown trout Salmo trutta competitive asymmetries.

    Science.gov (United States)

    Ulvan, Eva M; Finstad, Anders G; Ugedal, Ola; Berg, Ole Kristian

    2012-01-01

    One of the major challenges in ecological climate change impact science is to untangle the climatic effects on biological interactions and indirect cascading effects through different ecosystems. Here, we test for direct and indirect climatic drivers on competitive impact of Arctic char (Salvelinus alpinus L.) on brown trout (Salmo trutta L.) along a climate gradient in central Scandinavia, spanning from coastal to high-alpine environments. As a measure of competitive impact, trout food consumption was measured using (137)Cs tracer methodology both during the ice-covered and ice-free periods, and contrasted between lakes with or without char coexistence along the climate gradient. Variation in food consumption between lakes was best described by a linear mixed effect model including a three-way interaction between the presence/absence of Arctic char, season and Secchi depth. The latter is proxy for terrestrial dissolved organic carbon run-off, strongly governed by climatic properties of the catchment. The presence of Arctic char had a negative impact on trout food consumption. However, this effect was stronger during ice-cover and in lakes receiving high carbon load from the catchment, whereas no effect of water temperature was evident. In conclusion, the length of the ice-covered period and the export of allochthonous material from the catchment are likely major, but contrasting, climatic drivers of the competitive interaction between two freshwater lake top predators. While future climatic scenarios predict shorter ice-cover duration, they also predict increased carbon run-off. The present study therefore emphasizes the complexity of cascading ecosystem effects in future effects of climate change on freshwater ecosystems.

  14. Apo-states of calmodulin and CaBP1 control CaV1 voltage-gated calcium channel function through direct competition for the IQ domain

    Science.gov (United States)

    Findeisen, Felix; Rumpf, Christine; Minor, Daniel L.

    2013-01-01

    In neurons, binding of calmodulin (CaM) or calcium-binding protein 1 (CaBP1) to the CaV1 (L-type) voltage-gated calcium channel IQ domain endows the channel with diametrically opposed properties. CaM causes calcium-dependent inactivation (CDI) and limits calcium entry, whereas CaBP1 blocks CDI and allows sustained calcium influx. Here, we combine isothermal titration calorimetry (ITC) with cell-based functional measurements and mathematical modeling to show that these calcium sensors behave in a competitive manner that is explained quantitatively by their apo-state binding affinities for the IQ domain. This competition can be completely blocked by covalent tethering of CaM to the channel. Further, we show that Ca2+/CaM has a sub-picomolar affinity for the IQ domain that is achieved without drastic alteration of calcium binding properties. The observation that the apo-forms of CaM and CaBP1 compete with each other demonstrates a simple mechanism for direct modulation of CaV1 function and suggests a means by which excitable cells may dynamically tune CaV activity. PMID:23811053

  15. Enzyme-linked immunosorbent assay gliadin assessment in processed food products available for persons with celiac disease: a feasibility study for developing a gluten-free food database.

    Science.gov (United States)

    Agakidis, Charalampos; Karagiozoglou-Lampoudi, Thomais; Kalaitsidou, Marina; Papadopoulos, Theodoros; Savvidou, Afroditi; Daskalou, Efstratia; Dimitrios, Triantafyllou

    2011-12-01

    Inappropriate food labeling and unwillingness of food companies to officially register their own gluten-free products in the Greek National Food Intolerance Database (NFID) result in a limited range of processed food products available for persons with celiac disease (CDP). The objective of the study was to evaluate the feasibility of developing a gluten-free food product database based on the assessment of the gluten content in processed foods available for CDP. Gluten was assessed in 41 processed food products available for CDP. Group A consisted of 26 products for CDP included in the NFID, and group B contained 15 food products for CDP not registered in the NFID but listed in the safe lists of the local Celiac Association (CA). High-sensitivity ω-gliadin enzyme-linked immunosorbent assay (ELISA) was used for analysis. Gluten was lower than 20 ppm in 37 of 41 analyzed products (90.2%): in 24 of 26 (92.3%) products in group A and in 13 of 15 (86.7%) products in group B (P = .61). No significant difference was found between the 2 groups regarding gluten content. No product in either group contained gluten in excess of 100 ppm. Most of the analyzed products included in the Greek NFID or listed in the lists of the local CA, even those not officially labeled "gluten free," can be safely consumed by CDP. The use of commercially available ω-gliadin ELISA is able to identify those products that contain inappropriate levels of gluten, making feasible it to develop an integrated gluten-free processed food database.

  16. Diagnostic accuracy of the anti-glutamic acid decarboxylase antibody in type 1 diabetes mellitus: Comparison between radioimmunoassay and enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Murata, Takashi; Tsuzaki, Kokoro; Nirengi, Shinsuke; Watanabe, Tomokazu; Mizutani, Yukako; Okada, Hayami; Tsukamoto, Masami; Odori, Shinji; Nakagawachi, Reiko; Kawaguchi, Yaeko; Yoshioka, Fumi; Yamada, Kazunori; Shimatsu, Akira; Kotani, Kazuhiko; Satoh-Asahara, Noriko; Sakane, Naoki

    2017-07-01

    The distributer of the anti-glutamic acid decarboxylase antibody assay kit using radioimmunoassay (RIA) recently announced its discontinuation, and proposed an alternative kit using enzyme-linked immunosorbent assay (ELISA). The aim of the present study was to investigate the diagnostic values of the anti-glutamic acid decarboxylase antibody by RIA and ELISA among type 1 diabetes mellitus patients and control participants. A total of 79 type 1 diabetes mellitus patients and 79 age-matched controls were enrolled and assessed using RIA and ELISA. Sensitivity, specificity, positive predictive values and negative predictive values were calculated for cut-off values (RIA = 1.5 U/mL and ELISA = 5.0 U/mL, respectively). Kappa coefficients were used to test for agreements between the RIA and ELISA methods regarding the diagnosis of type 1 diabetes mellitus. The sensitivity, specificity, positive predictive values, and negative predictive values for diagnosing type 1 diabetes mellitus were 57.0, 97.5, 95.7, and 69.4% by RIA, and 60.8, 100.0, 100.0 and 71.8% by ELISA, respectively. The diagnosis of type 1 diabetes mellitus using the RIA and ELISA methods showed substantial agreement with the kappa values of 0.74 for all participants, and of 0.64 for the acute type; however, there was moderate agreement with the kappa value of 0.56 for the slowly progressive type. The present study suggests that both anti-glutamic acid decarboxylase antibody by RIA and ELISA was useful for diagnosing type 1 diabetes mellitus. However, in the slowly progressive type, the degree of agreement of these two kits was poorer compared with those in all participants or in the acute type. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

  17. Development and evaluation of an avian influenza, neuraminidase subtype 1, indirect enzyme-linked immunosorbent assay for poultry using the differentiation of infected from vaccinated animals control strategy.

    Science.gov (United States)

    Liu, Y; Mundt, E; Mundt, A; Sylte, M; Suarez, D L; Swayne, D E; García, M

    2010-03-01

    An indirect enzyme-linked immunosorbent assay (ELISA) was developed using baculovirus, purified, recombinant N1 protein from A/chicken/Indonesia/PA7/2003 (H5N1) virus. The N1-ELISA showed high selectivity for detection of N1 antibodies, with no cross-reactivity with other neuraminidase subtypes, and broad reactivity with sera to N1 subtype isolates from North American and Eurasian lineages. Sensitivity of the N1-ELISA to detect N1 antibodies in turkey sera, collected 3 wk after H1N1 vaccination, was comparable to detection of avian influenza antibodies by the commercial, indirect ELISAs ProFLOK AIV Plus ELISA Kit (Synbiotics, Kansas City, MO) and Avian Influenza Virus Antibody Test Kit (IDEXX, Westbrook, ME). However, 6 wk after vaccination, the Synbiotics ELISA kit performed better than the N1-ELISA and the IDEXX ELISA kit. An evaluation was made of the ability of the N1-ELISA to discriminate vaccinated chickens from subsequently challenged chickens. Two experiments were conducted, chickens were vaccinated with inactivated H5N2 and H5N9 viruses and challenged with highly pathogenic H5N1 virus, and chickens were vaccinated with recombinant poxvirus vaccine encoding H7 and challenged with highly pathogenic H7N1 virus. Serum samples were collected at 14 days postchallenge and tested by hemagglutination inhibition (HI), quantitative neuraminidase inhibition (NI), and N1-ELISA. At 2 days postchallenge, oropharyngeal swabs were collected for virus isolation (VI) to confirm infection. The N1-ELISA was in fair agreement with VI and HI results. Although the N1-ELISA showed a lower sensitivity than the NI assay, it was demonstrated that detection of N1 antibodies by ELISA was an effective and rapid assay to identify exposure to the challenge virus in vaccinated chickens. Therefore, N1-ELISA can facilitate a vaccination strategy with differentiation of infected from vaccinated animals using a neuraminidase heterologous approach.

  18. Validation of an enzyme-linked immunosorbent assay for the quantification of citrullinated histone H3 as a marker for neutrophil extracellular traps in human plasma.

    Science.gov (United States)

    Thålin, Charlotte; Daleskog, Maud; Göransson, Sophie Paues; Schatzberg, Daphne; Lasselin, Julie; Laska, Ann-Charlotte; Kallner, Anders; Helleday, Thomas; Wallén, Håkan; Demers, Mélanie

    2017-06-01

    There is an emerging interest in the diverse functions of neutrophil extracellular traps (NETs) in a variety of disease settings. However, data on circulating NETs rely largely upon surrogate NET markers such as cell-free DNA, nucleosomes, and NET-associated enzymes. Citrullination of histone H3 by peptidyl arginine deiminase 4 (PAD4) is central for NET formation, and citrullinated histone H3 (H3Cit) is considered a NET-specific biomarker. We therefore aimed to optimize and validate a new enzyme-linked immunosorbent assay (ELISA) to quantify the levels of H3Cit in human plasma. A standard curve made of in vitro PAD4-citrullinated histones H3 allows for the quantification of H3Cit in plasma using an anti-histone antibody as capture antibody and an anti-histone H3 citrulline antibody for detection. The assay was evaluated for linearity, stability, specificity, and precision on plasma samples obtained from a human model of inflammation before and after lipopolysaccharide injection. The results revealed linearity and high specificity demonstrated by the inability of detecting non-citrullinated histone H3. Coefficients of variation for intra- and inter-assay variability ranged from 2.1 to 5.1% and from 5.8 to 13.5%, respectively, allowing for a high precision. Furthermore, our results support an inflammatory induction of a systemic NET burden by showing, for the first time, clear intra-individual elevations of plasma H3Cit in a human model of lipopolysaccharide-induced inflammation. Taken together, our work demonstrates the development of a new method for the quantification of H3Cit by ELISA that can reliably be used for the detection of NETs in human plasma.

  19. A biolayer interferometry-based enzyme-linked aptamer sorbent assay for real-time and highly sensitive detection of PDGF-BB.

    Science.gov (United States)

    Gao, Shunxiang; Zheng, Xin; Wu, Jihong

    2018-04-15

    Accurate, fast and sensitive detection of disease-specific protein biomarkers, especially in blood, urine, or other bodily fluids, is an important approach to achieve early disease diagnosis. Platelet-derived growth factor-BB (PDGF-BB), a widely used biomarker, is involved in a substantial number of serious diseases, such as hepatic fibrosis, atherosclerosis, age-related macular degeneration and diabetic eye disease and is often over-expressed in human malignant tumors. Therefore, the development of sensitive and specific detection methods for PDGF-BB is of great importance for the early diagnosis of disease and assessments of patient recovery. In the current study, a biolayer interferometry-based enzyme-linked aptamer sorbent assay (BLI-ELASA) was successfully established for rapid (20-25min), high-throughput (8 or 16 samples) and real-time monitoring of PDGF-BB in clinical samples. The method exhibited a broad detection range from 0.5 to 1000ng/mL of PDGF-BB (good linear range from 0.5 to 10ng/mL), with a low detection limit of 0.08ng/mL. Moreover, BLI-ELASA was applied to the detection of PDGF-BB in spiked serum and urine samples and showed a high degree of selectivity for PDGF-BB, good reproducibility, and stability. We believe that the methodology in this work can be easily adapted to detect other biomolecules in clinical samples, including viruses, pathogens and toxins, in a rapid, sensitive, high-throughput and real-time manner. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Diagnostic efficacy of monoclonal antibody based sandwich enzyme linked immunosorbent assay (ELISA for detection of Fasciola gigantica excretory/secretory antigens in both serum and stool

    Directory of Open Access Journals (Sweden)

    Zoheiry Mona K

    2011-09-01

    Full Text Available Abstract Background This research was carried out to develop a reliable monoclonal antibody (MoAb-based sandwich enzyme linked immunosorbent assay (ELISA for the diagnosis of active Fasciola gigantica infection in both serum and stool for comparative purposes. Methods From a panel of MoAbs raised against F. gigantica excretory/secretory antigens (ES Ags, a pair (12B/11D/3F and 10A/9D/10G was chosen due to its high reactivity and strict specificity to F. gigantica antigen by indirect ELISA. Results The two MoAbs were of the IgG1 and IgG2a subclasses, respectively. Using SDS-PAGE and EITB, the selected MoAbs recognized 83, 64, 45 and 26 kDa bands of ES Ags. The lower detection limit of ELISA assay was 3 ng/ml. In stool, the sensitivity, specificity and diagnostic efficacy of ELISA was 96%, 98.2 and 97.1%; while in serum they were 94%, 94.6% and 94.3%, respectively. Moreover, a positive correlation was found between ova count in stool of F. gigantica infected patients and the OD readings of ELISA in both stool and serum samples (r = 0.730, p Conclusions These data showed that the use of MoAb-based sandwich ELISA for the detection of F. gigantica coproantigens in stool specimens was superior to serum samples; it provides a highly efficient, non-invasive technique for the diagnosis of active F. gigantica infection.

  1. Use of heavy water (D2O) in developing thermostable recombinant p26 protein based enzyme-linked immunosorbent assay for serodiagnosis of equine infectious anemia virus infection.

    Science.gov (United States)

    Singha, Harisankar; Goyal, Sachin K; Malik, Praveen; Singh, Raj K

    2014-01-01

    Thermostabilizing effect of heavy water (D2O) or deuterium oxide has been demonstrated previously on several enzymes and vaccines like oral poliovirus vaccine and influenza virus vaccine. In view of the above observations, effect of heavy water on in situ thermostabilization of recombinant p26 protein on enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of equine infectious anemia virus (EIAV) infection was investigated in the present study. The carbonate-bicarbonate coating buffer was prepared in 60% and 80% D2O for coating the p26 protein in 96-well ELISA plate and thermal stability was examined at 4 °C, 37 °C, 42 °C, and 45 °C over a storage time from 2 weeks to 10 months. A set of positive serum (n = 12) consisting of strong, medium, and weak titer strength (4 samples in each category) and negative serum (n = 30) were assessed in ELISA during the study period. At each time point, ELISA results were compared with fresh plate to assess thermal protective effect of D2O. Gradual increase in the stabilizing effect of 80% D2O at elevated temperature (37 °C < 42 °C < 45 °C) was observed. The 80% D2O provides the thermal protection to rp26 protein in ELISA plate up to 2 months of incubation at 45 °C. The findings of the present study have the future implication of adopting cost effective strategies for generating more heat tolerable ELISA reagents with extended shelf life.

  2. Use of Heavy Water (D2O in Developing Thermostable Recombinant p26 Protein Based Enzyme-Linked Immunosorbent Assay for Serodiagnosis of Equine Infectious Anemia Virus Infection

    Directory of Open Access Journals (Sweden)

    Harisankar Singha

    2014-01-01

    Full Text Available Thermostabilizing effect of heavy water (D2O or deuterium oxide has been demonstrated previously on several enzymes and vaccines like oral poliovirus vaccine and influenza virus vaccine. In view of the above observations, effect of heavy water on in situ thermostabilization of recombinant p26 protein on enzyme-linked immunosorbent assay (ELISA for serodiagnosis of equine infectious anemia virus (EIAV infection was investigated in the present study. The carbonate-bicarbonate coating buffer was prepared in 60% and 80% D2O for coating the p26 protein in 96-well ELISA plate and thermal stability was examined at 4°C, 37°C, 42°C, and 45°C over a storage time from 2 weeks to 10 months. A set of positive serum (n=12 consisting of strong, medium, and weak titer strength (4 samples in each category and negative serum (n=30 were assessed in ELISA during the study period. At each time point, ELISA results were compared with fresh plate to assess thermal protective effect of D2O. Gradual increase in the stabilizing effect of 80% D2O at elevated temperature (37°C < 42°C < 45°C was observed. The 80% D2O provides the thermal protection to rp26 protein in ELISA plate up to 2 months of incubation at 45°C. The findings of the present study have the future implication of adopting cost effective strategies for generating more heat tolerable ELISA reagents with extended shelf life.

  3. A sensitive double-antibody enzyme-linked immunosorbant assay for bovine myeloperoxidase and its application to serum and neutrophil extracts.

    Science.gov (United States)

    Cooray, R; Petersson, C G; Moberg, L; Båge, R

    1995-10-01

    The heme enzyme myeloperoxidase (MPO), with a spectral A430/A280 ratio > 0.78, was purified from isolated bovine neutrophils. Using highly specific anti-MPO monoclonal and anti-MPO polyclonal antibodies raised against MPO, a specific and sensitive double-antibody enzyme-linked immunosorbant assay (ELISA) was developed to measure bovine MPO in serum and neutrophil extracts. The ELISA shows good precision and accuracy, with intra- and interassay coefficients of variation of < 10% for MPO concentrations ranging from 0.5 to 50 ng/ml. The accuracy of the ELISA for measuring MPO in bovine serum was further confirmed by the similarity between the standard curve and curves obtained with successive dilutions of MPO-rich serum samples. The mean analytical recovery of MPO from serum was approximately 90%. Long delays between blood sampling and serum preparation were found to affect the level of MPO in the serum. Mean MPO values in the serum of healthy adult cows were 6.5 ng/ml, with a range of 3.5-15.3 ng/ml. In dairy cows with acute mastitis, mean serum MPO values were approximately 30 ng/ml, with a range of 6.0-59.6 ng/ml, and the elevation was markedly higher than the normal values (P = 0.0001). In isolated neutrophils from healthy cattle, MPO concentrations were found to be 7 x 10(-4) ng, with a range of 6.5-8.3 x 10(-4) ng/neutrophil. The ELISA was used to study the distribution of MPO in the bovine neutrophil granules; it was found to be localized to one distinct compartment.

  4. A protein A/G indirect enzyme-linked immunosorbent assay for the detection of anti-Brucella antibodies in Arctic wildlife.

    Science.gov (United States)

    Nymo, Ingebjørg H; Godfroid, Jacques; Åsbakk, Kjetil; Larsen, Anett K; das Neves, Carlos G; Rødven, Rolf; Tryland, Morten

    2013-05-01

    A species-independent indirect enzyme-linked immunosorbent assay (iELISA) based on chimeric protein A/G was established for the detection of anti-Brucella antibodies in Arctic wildlife species and compared to previously established brucellosis serological tests for hooded seals (Cystophora cristata), minke whales (Balaenoptera acutorostrata), sei whales (Balaenoptera borealis), fin whales (Balaenoptera physalus), and polar bears (Ursus maritimus), as well as bacteriology results for reindeer and caribou (Rangifer tarandus sp.). The protein A/G iELISA results were consistent with the other serological tests with Cohen kappa values between 0.47 and 0.92, and the protein A/G iELISA can thus offer a technically simple method for these species yielding results consistent with established brucellosis serological tests. Receiver operator characteristics analysis proved that the reindeer and caribou protein A/G iELISA results were consistent with the bacteriological gold standard with an area under the curve of 0.99, and the protein A/G iELISA was thus validated as a sensitive and specific serological method for the detection of anti-Brucella antibodies in reindeer and caribou. The binding of the antibodies from the respective species to protein A and G were also evaluated in the iELISA. The antibodies from hooded seals and polar bears reacted stronger to protein A than to G. The sei whale, fin whale, reindeer, and caribou antibodies reacted stronger to protein G than to A. The minke whale antibodies reacted to both protein A and G. There was a strong correlation (r s = 0.88-0.98) between the optical density results obtained with the iELISA with protein A/G and protein A or G, showing that protein A/G is as well suited as protein A or G for the detection of anti-Brucella antibodies in these species with the iELISA.

  5. Effects of thermal processing on the enzyme-linked immunosorbent assay (ELISA) detection of milk residues in a model food matrix.

    Science.gov (United States)

    Downs, Melanie L; Taylor, Steve L

    2010-09-22

    Food products and ingredients are frequently tested for the presence of undeclared allergenic food residues (including milk) using commercial enzyme-linked immunosorbent assays (ELISAs). However, little is understood about the efficacy of these kits with thermally processed foods. This study evaluated the performance of three milk ELISA kits with a model food processed by several methods. A model food (pastry dough squares) was spiked with nonfat dry milk at several concentrations. The pastry squares were processed by boiling (100 °C for 2 min), baking (190 °C for 30 min), frying (190 °C for 2 min), and retorting (121 °C for 20 min with 17 psi overpressure). Samples were analyzed with three commercial ELISA kits: Neogen Veratox Total Milk, ELISA Systems β-lactoglobulin, and ELISA Systems casein. The detection of milk residues depended upon the type of processing applied to the food and the specific milk analyte targeted by the ELISA kit. Poor recoveries were obtained in all processed samples (2-10% of expected values) using the β-lactoglobulin kit. Better recoveries were obtained in boiled samples (44 and 59%, respectively) using the total milk and casein kits. However, these kits performed poorly with baked (9 and 21%) and fried (7 and 18%) samples. Moderate recoveries were observed in retorted samples (23 and 28%). The decreased detection in processed samples is likely due to protein modifications, including aggregation and Maillard reactions, which affect the solubility and immunoreactivity of the antigens detected by the ELISA methods. The observed decreases in ELISA detection of milk are dramatic enough to affect risk-assessment decisions. However, a lower detection of milk residues does not necessarily indicate decreased allergenicity. These ELISA kits are not acceptable for all applications, and users should understand the strengths and limitations of each method.

  6. Development and use of an indirect enzyme-linked immunosorbent assay for detection of iridovirus exposure in gopher tortoises (Gopherus polyphemus) and eastern box turtles (Terrapene carolina carolina).

    Science.gov (United States)

    Johnson, April J; Wendland, Lori; Norton, Terry M; Belzer, Bill; Jacobson, Elliott R

    2010-05-19

    Iridoviruses, pathogens typically associated with fish and amphibians, have recently been shown to cause acute respiratory disease in chelonians including box turtles, red-eared sliders, gopher tortoises, and Burmese star tortoises. Case reports of natural infections in several chelonian species in the United States have been reported, however the prevalence remains unknown in susceptible populations of free-ranging chelonians. To determine the prevalence of iridovirus exposure in free-ranging gopher tortoises (Gopherus polyphemus) in the southeast United States, an indirect enzyme-linked immunosorbent assay (ELISA) was developed and used to evaluate plasma samples from wild gopher tortoises (G. polyphemus) from: Alabama (n=9); Florida (n=658); Georgia (n=225); Louisiana (n=12); Mississippi (n=28); and unknown locations (68) collected between 2001 and 2006. Eight (1.2%) seropositive tortoises were identified from Florida and seven (3.1%) from Georgia for an overall prevalence of 1.5%. Additionally, a population of eastern box turtles was sampled from a private nature sanctuary in Pennsylvania that experienced an outbreak of iridovirus the previous year, which killed 16 turtles. Only 1 turtle out of 55 survivors tested positive (1.8%). Results suggest a low exposure rate in chelonians to this pathogen; however, it is suspected that this is an underestimate of the true prevalence. Since experimental transmission studies and past outbreaks have shown a high rate of mortality in infected turtles, turtles may die before they develop an antibody response. Further, the duration of the antibody response is unknown and may also cause an underestimate of the true prevalence. Copyright 2009 Elsevier B.V. All rights reserved.

  7. Inhibitory effect of aqueous extract of different parts of Gossypium herbaceum on key enzymes linked with type 2 diabetes and oxidative stress in rat pancreas in vitro

    Directory of Open Access Journals (Sweden)

    Ayodeji Augustine Olabiyi

    2016-06-01

    Full Text Available This study sought to determine the inhibitory effect of aqueous extract of different parts (bark, leaf, and flower of cotton plant (Gossypium herbaceum on key enzymes linked with type 2 diabetes and oxidative stress in rat pancreas in vitro. The aqueous extract (1:10 w/v of Gossypium herbaceum was prepared and the ability of the extract to inhibit the activity of α-amylase and α-glucosidase as well as activities of pro-oxidant Fe2+-induced lipid peroxidation was determined spectrophotometrically. The results revealed that the three varieties were able to inhibit the activity of α-amylase and α-glucosidase in rat's pancreas in a dose dependent manner (0–88.8 mg/ml. Also, the incubation of pancreas tissue homogenate in the presence of Fe2+ caused a significant increase (233.3% in the malondialdehyde (MDA content of pancreas homogenate, nevertheless, the introduction of the aqueous extract inhibited MDA production dose dependently (0–33.33 mg/ml and also exhibited further antioxidant properties as represented by their high radical scavenging and Fe2+ chelating abilities. Inhibition of α-amylase and α-glucosidase activities has been the primary treatment for the management/prevention of type 2 diabetes. Therefore, the α-amylase and α-glucosidase inhibitory activities of aqueous extracts of different parts of Gossypium herbaceum in rat pancreas and prevention of lipid peroxidation in the tissue may be attributed to the presence of polyphenol content of the plant.

  8. Evaluation of an enzyme-linked immunosorbent assay based on crude Leishmania histone proteins for serodiagnosis of human infantile visceral leishmaniasis.

    Science.gov (United States)

    Lakhal, Sami; Mekki, Salima; Ben-Abda, Imène; Mousli, Mohamed; Amri, Fethi; Aoun, Karim; Bouratbine, Aïda

    2012-09-01

    Human visceral leishmaniasis (VL) is routinely diagnosed by detecting IgG that specifically binds to Leishmania antigens. The enzyme-linked immunosorbent assay (ELISA) remains a widely used method. However, the biggest challenge remains the choice of antigen with the highest specificity and sensitivity. This study is aimed at assessing the diagnostic performances of crude Leishmania histone (CLH) protein-based ELISAs in Mediterranean VL patients. The CLH proteins were biochemically purified from promastigote nuclear extracts. Their reactivities were analyzed by Western blotting (WB) using rabbit polyclonal antibodies against Leishmania recombinant histones and sera from VL patients, respectively. Then, the diagnostic potential of CLH proteins was validated by the CLH-based ELISA using 42 infantile VL patients' sera and 70 control subjects. The CLH-based ELISA performance was compared to that of the soluble Leishmania antigen (SLA)- and the recombinant K39 (rK39)-based ELISAs. Analysis of the WB profile with the use of polyclonal antibodies confirmed the histone origin of low molecular mass proteins (12 to 16 kDa). All VL samples tested presented antibodies reacting against different antigen fractions; however, recognition patterns were different depending on the reactivity of each serum. CLH-based ELISA showed an excellent ability to discriminate between VL cases and healthy controls (97.6% sensitivity and 100% specificity). It had a diagnostic performance similar to that of rK39-based ELISA (97.6% sensitivity and 97.1% specificity, P = 0.5) and a better serodiagnosis accuracy than the SLA-based ELISA (85.7% sensitivity and 90% specificity, P histone extract could be a valuable antigen for clinical use.

  9. Kinetic determination of vitellogenin induction in the epidermis of cyprinid and perciform fishes: Evaluation of sensitive enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Allner, Bernhard; Hennies, Mark; Lerche, Cristiano F; Schmidt, Thomas; Schneider, Klaus; Willner, Marco; Stahlschmidt-Allner, Petra

    2016-12-01

    Induction of vitellogenin (VTG) in male and immature fish is a standardized endpoint in endocrine-disruption testing. To establish a nondestructive swab sampling method, VTG induction in the epidermis of Cypriniformes and Perciformes species was investigated. Both VTG and estrogen receptor genes are expressed in epidermal cells. Immunoaffinity and mass fingerprint analyses show induction of identical VTG peptides in liver and epidermis. Induction of VTG by estradiol (E2) and bisphenol A (BPA) in the epidermis was quantified with homolog enzyme-linked immunosorbent assays. Initial values in juveniles and males were below 1 ng VTG/mL extraction buffer. Exposure to E2 led to values between 200 ng/mL and 4600 ng/mL in cyprinids and between 10 ng/mL and 81 ng/mL in perciforms. Exposure to BPA increased VTG amounts to 250 ng/mL in fathead minnows, 1360 ng/mL in goldfish, 100 ng/mL in zebrafish, and 12 ng/mL in bluegills. Serum VTG contents demonstrated a similar dose-response pattern in the epidermis and the blood. These results show that VTG induction may be reliably assessed in the skin mucus of fishes, demonstrating the suitability of this biological sample for investigating estrogenic activity in compliance with Organisation for Economic Co-operation and Development standard protocols. This broadens the perspectives in toxicological screening and environmental monitoring, reducing the number of tested animals and minimizing harmful effects for animals, allowing for follow-up of individual induction profiles. Environ Toxicol Chem 2016;35:2916-2930. © 2016 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2016 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

  10. Inhibitory effect of some tropical green leafy vegetables on key enzymes linked to Alzheimer's disease and some pro-oxidant induced lipid peroxidation in rats' brain.

    Science.gov (United States)

    Oboh, Ganiyu; Akinyemi, Ayodele Jacobson; Ademiluyi, Adedayo Oluwaseun; Bello, Fatai Olumide

    2014-05-01

    This study sought to investigate the inhibitory effect of some commonly consumed Nigerian green leafy vegetables (raw and blanched) on acetylcholinesterase and butyrylcholinesterase (key enzyme linked to Alzheimer's disease) activities and some pro-oxidants (FeSO4, Sodium nitroprusside and Quinolinic acid) induced lipid peroxidation in rat brain in vitro. Three commonly consumed green leafy vegetables in Nigeria [Amarantus cruentus (Arowojeja), Struchium sparganophora (Ewuro-odo) and Telfairia occidentalis (Ugwu] were blanched in hot water for 10 min, and the extracts of the raw and blanched vegetables were prepared and used for subsequent analysis. The result revealed that all the vegetables inhibited acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activity as well as the pro-oxidants induced lipid peroxidation in rat brain in a dose dependent manner; however, Amarantus cruentus extract (EC50 = 97.9 μg/ml) had the highest inhibitory effect on acetylcholinesterase activity while Telfairia occidentalis extract (EC50 = 52.7 μg/ml) had the highest inhibitory effect on butyrylcholinesterase activity. However, blanching of the vegetables caused a significant (P vegetables on AChE activities while it enhanced the inhibition of the pro-oxidants induced lipid peroxidation in rat brain in vitro. Therefore, some of the possible mechanism by which green leafy vegetables exert their neuroprotective activities could be through the inhibition of acetylcholinesterase and butyrylcholinesterase activities and prevention of lipid peroxidation in the brain. However, blanching of the vegetables could reduce their ability to inhibit acetylcholinesterase and butyrylcholinesterase activity.

  11. Lateral flow immunoassay and enzyme linked immunosorbent assay as effective immunomethods for the detection of synthetic cannabinoid JWH-200 based on the newly synthesized hapten.

    Science.gov (United States)

    Fojtíková, Lucie; Šuláková, Anna; Blažková, Martina; Holubová, Barbora; Kuchař, Martin; Mikšátková, Petra; Lapčík, Oldřich; Fukal, Ladislav

    2018-01-01

    In recent years, the use of synthetic cannabinoids (SCs) as drugs of abuse has greatly increased. SCs are associated with a risk of severe poisoning or even death. Therefore, more rapid, cost effective and reliable methods are needed, especially for the screening of drivers after traffic accidents and for detailed toxicological analysis in forensic laboratories. In this study, we developed a lateral flow immunoassay (LFIA) and an enzyme linked immunosorbent assay (ELISA) for the detection of JWH-200 in oral fluids. For this purpose a new hapten was prepared using a ten-step synthetic route. The developed immuno methods are based on antibodies obtained from rabbit immunized with synthesized hapten conjugated to carrier protein. The proposed methods are highly sensitive (LOD LFIA  = 0.08 ± 0.04 ng mL -1 ; LOD ELISA  = 0.04 ± 0.02 ng mL -1 ). They were applied to the quantification of JHW-200 in spiked oral fluids. The recoveries ranged from 82 to 134% for both methods. The results correlated excellently with results obtained using UHPLC-MS/MS (R 2 LFIA  = 0.99; R 2 ELISA  = 0.99). Our developed methods could be an important tool for analyses of JWH-200 in human oral fluids. The one-step LFIA is particularly suitable for roadside and on-site monitoring due to the rapid qualitative results it delivers, while the ELISA is especially useful for laboratory quantitative analyses of positive samples captured by LFIA.

  12. Enzyme-linked immunosorbent assays based on Neospora caninum dense granule protein 7 and profilin for estimating the stage of neosporosis.

    Science.gov (United States)

    Hiasa, Jun; Nishimura, Maki; Itamoto, Kazuhito; Xuan, Xuenan; Inokuma, Hisashi; Nishikawa, Yoshifumi

    2012-03-01

    Neospora caninum is an intracellular protozoan parasite that causes bovine and canine neosporosis, characterized by fetal abortion and neonatal mortality and by neuromuscular paralysis, respectively. Although many diagnostic methods to detect parasite-specific antibodies or parasite DNA have been reported, to date no effective serodiagnostic techniques for estimating pathological status have been described. Our study aimed to elucidate the relationship between the parasite-specific antibody response, parasite activation, and neurological symptoms caused by N. caninum infection by using a recombinant antigen-based enzyme-linked immunosorbent assay. Among experimentally infected mice, anti-N. caninum profilin (NcPF) antibody was only detected in neurologically symptomatic animals. Parasite numbers within the brains of the symptomatic mice were significantly higher than those in asymptomatic animals. In addition, anti-NcPF and anti-NcGRA7 antibodies were mainly detected at the acute stage in experimentally infected dogs, while anti-NcSAG1 antibody was produced during both acute and chronic stages. Furthermore, among anti-NcSAG1 antibody-positive clinical dogs, the positive rates of anti-NcGRA7 and anti-NcPF antibodies in the neurologically symptomatic dogs were significantly higher than those in the non-neurologically symptomatic animals. Our results suggested that the levels of anti-NcGRA7 and anti-NcPF antibodies reflect parasite activation and neurological symptoms in dogs. In conclusion, antibodies against NcGRA7 and NcPF may have potential as suitable indicators for estimating the pathological status of neosporosis.

  13. Evaluation of Two Enzyme-Linked Immunosorbent Assay Kits for Chikungunya Virus IgM Using Samples from Deceased Organ and Tissue Donors.

    Science.gov (United States)

    Prince, Harry E; Altrich, Michelle L; Nowicki, Marek J

    2016-10-01

    The identification of nearly 3,500 cases of chikungunya virus (CHIKV) infection in U.S. residents returning in 2014 and 2015 from areas in which it is endemic has raised concerns within the transplant community that, should recently infected individuals become organ and/or tissue donors, CHIKV would be transmitted to transplant recipients. Thus, tests designed to detect recent CHIKV infection among U.S. organ and tissue donors may become necessary in the future. Accordingly, we evaluated 2 enzyme-linked immunosorbent assays (ELISAs) for CHIKV IgM readily available in the United States using 1,000 deidentified serum or plasma specimens collected from donors between November 2014 and March 2015. The Euroimmun indirect ELISA identified 38 reactive specimens; however, all 38 were negative for CHIKV IgG and IgM in immunofluorescence assays (IFAs) conducted at a reference laboratory and, thus, were falsely reactive in the Euroimmun CHIKV IgM assay. The InBios IgM-capture ELISA identified 26 reactive samples, and one was still reactive (index ≥ 1.00) when retested using the InBios kit with a background subtraction modification to identify false reactivity. This reactive specimen was CHIKV IgM negative but IgG positive by IFAs at two reference laboratories; plaque reduction neutralization testing (PRNT) demonstrated CHIKV-specific reactivity. The IgG and PRNT findings strongly suggest that the InBios CHIKV IgM-reactive result represents true reactivity, even though the IgM IFA result was negative. If testing organ/tissue donors for CHIKV IgM becomes necessary, the limitations of the currently available CHIKV IgM ELISAs and options for their optimization must be understood to avoid organ/tissue wastage due to falsely reactive results. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  14. Influence of pigments and protein aging on protein identification in historically representative casein-based paints using enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Ren, Fang; Atlasevich, Natalya; Baade, Brian; Loike, John; Arslanoglu, Julie

    2016-01-01

    A systematic study on the influence of pigments and sample aging on casein identification was performed on 30 reconstructed paints. The protein in all the paints was extracted into solution for analysis. The amount of protein that can be retrieved for solution-based analysis in each of the reconstructed paints was studied with a well-developed NanoOrange method before and after artificial aging. The results showed that in the paints with calcium phosphate (in bone black) and copper carbonate, hydroxide, or acetate (in verdigris and azurite), the amount of protein that can be retrieved for liquid-phase analysis is much smaller than the other paints, indicating that the protein degradation was accelerated significantly in those paints. Carbon (in vine black), calcium carbonate (in natural chalk), and calcium sulfate (terra alba gypsum and ground alabaster) did not affect much the amount of protein that can be retrieved in the paints compared to non-pigmented binder, meaning that the protein degradation rate was not affected much by those pigments. Artificial aging was observed to decrease the amount of retrievable protein in all the reconstructed paints that were studied. The enzyme-linked immunosorbent assay (ELISA) method was applied to the 28 reconstructed paints (except two verdigris paints) to assess the protein identification. The ELISA responses from the different paints were compared at fixed protein concentrations. Natural chalk, bone black, raw sienna, stack lead white, and cochineal red-violet lake had the lowest ELISA signal in this study, which indicated that the binding sites (epitopes) on the target protein in these paints are likely to deteriorate more than those in the other paints. Artificial aging did not influence the ELISA response as much as the pigments when the protein concentration was kept the same for the paints that were studied.

  15. Impact of grey zone sample testing by enzyme-linked immunosorbent assay in enhancing blood safety: Experience at a tertiary care hospital in North India.

    Science.gov (United States)

    Solanki, Archana; Singh, Abhay; Chaudhary, Rajendra

    2016-01-01

    Enzyme-linked immunosorbent assay (ELISA) used for screening blood donors for transfusion transmitted infections (TTIs) can sometimes fail to detect blood donors who are recently infected or possessing the low strength of pathogen. Estimation of a grey zone in ELISA testing and repeat testing of grey zone samples can further help in reducing the risks of TTI in countries where nucleic acid amplification testing for TTIs is not feasible. Grey zone samples with optical density (OD) lying between cut-off OD and 10% below the cut-off OD (cut-off OD × 0.9) were identified during routine ELISA testing. On performing repeat ELISA testing on grey zone samples in duplicate, the samples showing both OD value below grey zone were marked nonreactive, and samples showing one or both OD value in the grey zone were marked indeterminate. The samples on repeat testing showing one or both OD above cut-off value were marked positive. About 119 samples (77 for hepatitis B virus [HBV], 23 for human immunodeficiency virus [HIV], and 19 for hepatitis C virus [HCV]) were found to be in grey zone. On repeat testing of these samples in duplicate, 70 (58.8%) samples (45 for HBV, 12 for HIV, and 13 for HCV) were found to be reactive. Six (5%) samples (four for HBV, one for HIV, and one for HCV) were found to be indeterminate. Seventy donors initially screened negative, were found out to be potentially infectious on repeat grey zone testing. Thus, estimation of grey zone samples with repeat testing can further enhance the safety of blood transfusion.

  16. Real-time PCR and enzyme-linked fluorescent assay methods for detecting Shiga-toxin-producing Escherichia coli in mincemeat samples.

    Science.gov (United States)

    Stefan, A; Scaramagli, S; Bergami, R; Mazzini, C; Barbanera, M; Perelle, S; Fach, P

    2007-03-01

    This work aimed to compare real-time polymerase chain reaction (PCR) with the commercially available enzyme-linked fluorescent assay (ELFA) VIDAS ECOLI O157 for detecting Escherichia coli O157 in mincemeat. In addition, a PCR-based survey on Shiga-toxin-producing E. coli (STEC) in mincemeat collected in Italy is presented. Real-time PCR assays targeting the stx genes and a specific STEC O157 sequence (SILO157, a small inserted locus of STEC O157) were tested for their sensitivity on spiked mincemeat samples. After overnight enrichment, the presence of STEC cells could be clearly determined in the 25 g samples containing 10 bacterial cells, while the addition of five bacteria provided equivocal PCR results with Ct values very close to or above the threshold of 40. The PCR tests proved to be more sensitive than the ELFA-VIDAS ECOLI O157, whose detection level started from 50 bacterial cells/25 g of mincemeat. The occurrence of STEC in 106 mincemeat (bovine, veal) samples collected from September to November 2004 at five different points of sale in Italy (one point of sale in Arezzo, Tuscany, central Italy, two in Mantova, Lombardy, Northern Italy, and two in Bologna, Emilia-Romagna, upper-central Italy) was less than 1%. Contamination by the main STEC O-serogroups representing a major public health concern, including O26, O91, O111, O145, and O157, was not detected. This survey indicates that STEC present in these samples are probably not associated with pathogenesis in humans.

  17. Architectural Competition and BIM

    DEFF Research Database (Denmark)

    Sørensen, Nils Lykke; Frandsen, Anne Kathrine; Øien, Turid Borgestrand

    2015-01-01

    on architecturalcompetitions, a series of interviews was conducted with building clients as well as architects, focusing on the impact of the above-mentioned changes within the building sector on architectural competitions as an institution. In the interviews, ICT and notleast BIM was a recurring theme that both parties saw...... as having a positive impact on competitions. But when looking closely into the answers, these revealed diverse understandings of how and why the impact of BIM on competitions could be said to be positive. The paper sheds light on the interaction between the actors (building clients, architects and client...... consultants) and the applied technologies (competition forms, ICT tools, directives) in architectural competitions in a theoretical actor-network perspective. The diverging understandings of the role of BIM are demonstrating one of many negotiations in progress in the network of architectural competitions...

  18. COMPETITIVENESS AND COMPETITIVE ORIENTATIONS: EVALUATION OF STUDENTS

    Directory of Open Access Journals (Sweden)

    G. Z. Efimova

    2017-01-01

    Full Text Available Introduction. Education of a competitive student is a strategically significant problem of the system of higher education in modern social and economic conditions. Personal competitiveness and competitive orientations – priority quality of future expert for successful future professional experience.The aim of the present research is to study factors of competitive orientations formation and criteria for evaluation of competitiveness of student’s youth in the Russian society.Methodology and research methods. Results of theoretical researches of Russian and foreign researchers are generalized; secondary analysis of data based on results of sociological researches and analysis of official statistical data are carried out. The results of the sociological survey undertaken in 2017 on the basis of statistical methods were processed and studied by the instrumentality of IBM SPSS Statistics 23 program; 1196 students of institutions of higher and secondary vocational education of the Tyumen region took part.Results and scientific novelty. It is stated that senior students feel themselves more competitive. It is revealed that a quarter of students who took part in the survey, generally men, count themselves competitive. A continuous distance of goal-setting is recorded among these respondents; in every third case they have plans of professional growth for five and more years that allows them to build attractive competitive strategy.The level of the competitiveness is directly connected with such indicators as “social stratum”, “overall life satisfaction”, “self-esteem of health”, “tendency to lead a healthy lifestyle” and “the level of trust in the surrounding people”. Mostly the students oriented on competition look into the future with confidence and optimism.Respondents focused on the competitiveness were more tend to demonstrate their abilities and cause admiration, have a creative approach towards work, be ready for surprises

  19. Phenolic constituents and modulatory effects of Raffia palm leaf (Raphia hookeri extract on carbohydrate hydrolyzing enzymes linked to type-2 diabetes

    Directory of Open Access Journals (Sweden)

    Felix A. Dada

    2017-10-01

    Full Text Available This study sought to investigate the effects of Raffia palm (Raphia hookeri leaf extract on enzymes linked to type-2 diabetes mellitus (T2DM and pro-oxidant induced oxidative stress in rat pancreas. The extract was prepared and its α-amylase and α-glucosidase inhibitory effects were determined. Radical [2,2-diphenyl-1-picrylhydrazyl (DPPH] scavenging and Fe2+-chelating abilities, and inhibition of Fe2+-induced lipid peroxidation in rat pancreas homogenate were assessed. Furthermore, total phenol and flavonoid contents, reducing property, and high performance liquid chromatography diode array detector (HPLC-DAD fingerprint of the extract were also determined. Our results revealed that the extract inhibited α-amylase (IC50 = 110.4 μg/mL and α-glucosidase (IC50 = 99.96 μg/mL activities in concentration dependent manners which were lower to the effect of acarbose (amylase: IC50 = 18.30 μg/mL; glucosidase: IC50 = 20.31 μg/mL. The extract also scavenged DPPH radical, chelated Fe2+ and inhibited Fe2+-induced lipid peroxidation in rat pancreas all in concentration dependent manners with IC50 values of 402.9 μg/mL, 108.9 μg/mL and 367.0 μg/mL respectively. The total phenol and flavonoid contents were 39.73 mg GAE/g and 21.88 mg QAE/g respectively, while the reducing property was 25.62 mg AAE/g. The HPLC analysis revealed the presence of chlorogenic acid (4.17 mg/g and rutin (5.11 mg/g as the major phenolic compounds in the extract. Therefore, the ability of the extract to inhibit carbohydrate hydrolyzing enzymes and protect against pancreatic oxidative damage may be an important mechanisms supporting its antidiabetic properties and could make Raffia palm leaf useful in complementary/alternative therapy for management of T2DM. However, further studies such as in vivo should be carried out.

  20. A New Enzyme-Linked Immunosorbent Assay for a Total Anti-T Lymphocyte Globulin Determination: Development, Analytical Validation, and Clinical Applications.

    Science.gov (United States)

    Montagna, Michela; La Nasa, Giorgio; Bernardo, Maria E; Piras, Eugenia; Avanzini, Maria A; Regazzi, Mario; Locatelli, Franco

    2017-06-01

    Anti-T lymphocyte globulin (ATLG) modulates the alloreactivity of T lymphocytes, reducing the risk of immunological posttransplant complications, in particular rejection and graft-versus-host disease, after allogeneic hematopoietic stem cell transplantation (HSCT). We developed and validated a new enzyme-linked immunosorbent assay (ELISA) method to measure serum levels of total ATLG and evaluate the pharmacokinetics (PK) of the drug in children with β-Thalassemia, receiving allogeneic HSCT. Diluted serum samples were incubated with Goat-anti-Rabbit IgG antibody coated on a microtiter plate and then, with Goat-anti-Human IgG labeled with horseradish peroxidase. After incubation and washings, substrate solution was added and absorbance was read at 492 nm. ATLG concentrations in samples were determined by interpolation from a standard curve (range: 200-0.095 ng/mL), prepared by diluting a known amount of ATLG in phosphate-buffered saline (PBS). Low, medium, and high-quality control concentrations were 1.56, 6.25, and 25 ng/mL, respectively. This method was developed and validated within the acceptance criteria in compliance with the Guidelines for a biological method validation: the sensitivity of the method was 0.095 ng/mL. We analyzed serum samples from 14 children with β-Thalassemia who received ATLG (Grafalon) at a dose of 10 mg/kg administered as intravenous (IV) infusion on days -5, -4, and -3 before HSCT (day 0). Blood sampling for PK evaluation was performed on days -5, -4, and -3 before and after drug infusion; and then from day -2 to +56. The median total ATLG levels pre-IVand post-IV were 0 and 118 mcg/mL on day -5; 85.9 and 199.2 mcg/mL on day -4; 153 and 270.9 mcg/mL on day -3, respectively. The median PK values of CL was 0.0029 (range: 0.0028-0.0057) L·kg·d, Vd was 0.088 (range: 0.025-0.448) L/kg and t1/2 was 20.2 (range: 5.8-50.2) days. These data suggest that given the marked interindividual variability of total ATLG disposition, the development of

  1. Isolation of a 14 kDa antigen from Taenia solium cyst fluid by HPLC and its evaluation in enzyme linked immunosorbent assay for diagnosis of porcine cysticercosis.

    Science.gov (United States)

    Assana, E; Kanobana, K; Tume, C B; Zoli, P A; Nguekam; Geerts, S; Berkvens, D; Dorny, P

    2007-06-01

    A fraction with a major band of 14kDa was obtained from crude cyst fluid of Taenia solium cysticerci by 2-step chromatography. A first fraction isolated by gel filtration (Sephacryl S-300 high resolution) was purified using an anion exchange column (Mono Q HR 5/5) on high performance liquid chromatography. Evaluation of the analytic sensitivity of this fraction (F3) was carried out in an antibody enzyme linked immunosorbent assay (Ab-ELISA-F3) using serum samples from pigs experimentally infected with different doses of T. solium eggs. The cross-reactivity of F3 was evaluated with serum samples from pigs that were naturally or experimentally infected with Taenia hydatigena, Taenia saginata asiatica, Fasciola hepatica, Trichinella spiralis, Metastrongylus apri, Trypanosoma congolense and Sarcoptes scabiei, and with serum samples of rabbits hyper-immunised with metacestode cyst fluid of T. hydatigena and T. solium. Antibody titres of lightly or heavily infected pigs differed in their kinetics. However, the increase in F3-specific antibodies could not be related to the infection level. Analysis of the specificity of the F3 showed that serum samples of pigs infected with other parasites did not recognise this antigen. Cross-reaction with T. hydatigena occurred in ELISA using cyst fluid as antigen, but the F3 antigen fraction was not recognized by rabbit hyper-immune serum samples to T. hydatigena. Evaluation of the diagnostic sensitivity and specificity of the Ab-ELISA-F3 was done by a non-parametric receiver operating characteristic (ROC) analysis using 66 serum samples from Zambian village pigs. The total number of cysticerci of these pigs was determined by dissection (28 pigs harboured T. solium cysticerci and 38 were negative at dissection). In addition, 58 serum samples from Cameroonian pigs (28 pigs from cysticercosis-free farms and 30 pigs with cysticerci at tongue inspection) were used in a separate ROC analysis. The results from the ROC analysis yielded a low

  2. Enzyme-linked immunosorbent assays for detection of anti-transcriptional intermediary factor-1 gamma and anti-Mi-2 autoantibodies in dermatomyositis.

    Science.gov (United States)

    Fujimoto, Manabu; Murakami, Akihiro; Kurei, Shunsuke; Okiyama, Naoko; Kawakami, Atsushi; Mishima, Michiaki; Sato, Shinji; Seishima, Mariko; Suda, Takafumi; Mimori, Tsuneyo; Takehara, Kazuhiko; Kuwana, Masataka

    2016-12-01

    Autoantibodies against transcriptional intermediary factor 1 (TIF1) and Mi-2 are selectively detected in patients with dermatomyositis (DM). To measure these antibodies readily, the development of reliable ELISA systems has been needed. This study aimed to establish enzyme-linked immunosorbent assays (ELISAs) for anti-TIF1γ and anti-Mi-2β antibodies (Abs) and to assess their utility. Serum samples were obtained from 104 patients with classic DM, 68 with clinically amyopathic DM (CADM) and 70 with polymyositis, who were followed up at 8 medical centers across Japan. Serum samples from 190 patients with other connective tissue diseases (CTDs) and 123 healthy individuals were also assessed. Serum antibody levels were examined by ELISAs coated with full-length TIF1γ or Mi-2β proteins produced by a baculovirus expression system. To assess the cross-reactivity, partial-length Mi-2β proteins with or without mutations were produced and examined for reactivity. When compared with immunoprecipitation assay, anti-TIF1γ Ab ELISA showed 100% sensitivity and 100% specificity, while anti-Mi-2β Ab ELISA showed 100% sensitivity and 99.6% specificity. Anti-TIF1γ Ab was positive in 30 (28.8%) with classic DM and 4 (5.9%) with CADM, whereas 14 (13.5%) with classic DM, but none with CADM, were positive for anti-Mi-2β Ab. Of 30 anti-TIF1γ Ab-positive DM patients, 23 (67.6%) had malignancy. Anti-Mi-2β Ab-positive serum samples exhibited modest cross-reactivity with the TIF1γ protein due to the homologous amino acid sequence containing cysteines in their plant homeodomains. The current study demonstrates the utility of newly established ELISAs for anti-TIF1γ and anti-Mi-2β Abs, which can serve as easier detection systems for routine testing. Copyright © 2016 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  3. Retail competition

    International Nuclear Information System (INIS)

    1998-01-01

    Retail competition as the cornerstone of a competitive electricity marketplace was the subject of the seventh in the series of policy discussion papers developed at the Market Design Conference. Concern was expressed that because of the complexities involved in market design and technical implementation, the retail competition may lag behind other elements of the implementation of the new market design. A variety of key issues were debated, including the role of physical versus financial contracts, the form of retail competition and financial settlement systems in the short term, the requirement to separate 'competitive' (metering, billing, maintenance, consumer education) from non-competitive' (the transmission wires) services and the role of municipal electric utilities. It was agreed that the IMO should play an important role in defining and enforcing the separation of services, and that as a general rule, the development of policy in this area should be guided by the principle of maximizing the potential for competition

  4. Influence of Anti-FloR Antibody on Florfenicol Accumulation in Florfenicol-Resistant Escherichia coli and Enzyme-Linked Immunosorbent Assay for Detection of Florfenicol-Resistant E. coli Isolates

    OpenAIRE

    Wu, Beibei; Xia, Chun; Du, Xiangdang; Cao, Xingyuan; Shen, Jianzhong

    2006-01-01

    To detect florfenicol-resistant Escherichia coli isolates by enzyme-linked immunosorbent assay (ELISA), anti-FloR1 antibodies were produced in mice using a recombinant glutathione S-transferase (GST)-FloR1 protein, which was expressed in a prokaryote expression system, as the antigen. The specificity of the murine anti-GST-FloR1 antibody and its influence on florfenicol accumulation in florfenicol-resistant isolates were investigated using Western blotting and high-performance liquid chromato...

  5. Development of a nanobody-alkaline phosphatase fusion protein and its application in a highly sensitive direct competitive fluorescence enzyme immunoassay for detection of ochratoxin A in cereal.

    Science.gov (United States)

    Liu, Xing; Xu, Yang; Wan, De-bin; Xiong, Yong-hua; He, Zhen-yun; Wang, Xian-xian; Gee, Shirley J; Ryu, Dojin; Hammock, Bruce D

    2015-01-20

    A rapid and sensitive direct competitive fluorescence enzyme immunoassay (dc-FEIA) for ochratoxin A (OTA) based on a nanobody (Nb)-alkaline phosphatase (AP) fusion protein was developed. The VHH (variable domain of heavy chain antibody) gene of Nb28 was subcloned into the expression vector pecan45 containing the AP double-mutant gene. The Nb28-AP construct was transformed into Escherichia coli BL21(DE3)plysS, and soluble expression in bacteria was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot. Both the Nb properties and AP enzymatic activity were validated by colorimetric and fluorometric analysis. The 50% inhibitory concentration and the detection limit of the dc-FEIA were 0.13 and 0.04 ng/mL, respectively, with a linear range of 0.06-0.43 ng/mL. This assay was compared with LC-MS/MS, and the results indicated the reliability of Nb-AP fusion protein-based dc-FEIA for monitoring OTA contamination in cereal.

  6. Political Competitiveness

    OpenAIRE

    Casey B. Mulligan; Kevin K. Tsui

    2006-01-01

    Political competitiveness - which many interpret as the degree of democracy - can be modeled as a monopolistic competition. All regimes are constrained by the threat of "entry," and thereby seek some combination of popular support and political entry barriers. This simple model predicts that many public policies are unrelated to political competitiveness, and that even unchallenged nondemocratic regimes should tax far short of their Laffer curve maximum. Economic sanctions, odious debt repudi...

  7. Field trial of brucellosis competitive ELISA

    International Nuclear Information System (INIS)

    Perez, B.; Rojas, M.

    1998-01-01

    2990 sera samples from cattle were tested for antibodies to Brucella abortus using 8 serological tests for. The tests used were Rose Bengal (RBT), Buffer Plate Agglutination Test (BPAT), Complement Fixation (CFT), 2 Indirect and 2 Competitive Enzyme Linked Immunosorbent Assays (ELISA). Bacteriological evaluation from milk was done also. All tests were compared with respect to diagnostic specificity in vaccinated herds which were considered to be Brucella-free. The diagnostic specificity of the Indirect and Competitive ELISA was greater than 99,8%. Estimates of relative sensitivity were obtained from infected herds. The diagnostic sensitivity of the Indirect ELISA was greater than 95,8% and for the Competitive ELISA between 98,8 and 100 %, the last value refers to the Competitive ELISA Prototype II (SLPS antigen/M84 Mab), which was found highly suitable to differentiate vaccinated from brucella-infected cattle. The use of C-ELISA II for monitoring bovine populations under an eradication programme is recommended. (author)

  8. Pop competitiveness

    OpenAIRE

    Roberto Cellino; Anna Soci

    2002-01-01

    Very few economic terms are used as much as competitiveness in economics. This article deals with the different meanings of competitiveness, at the level of a firm, at the level of the local area, and at the level of the country. It analyzes the problems of consistency among the available definitions and among the indicators used to measurecompetitiveness.

  9. Competitiveness factors

    OpenAIRE

    Popa Liliana-Viorica

    2012-01-01

    Porter's theory supports the idea that, despite the globalization of production and trade, the competitive advantage is created in a national framework, nations, through their institutional, natural, cultural, economic characteristics ultimately determining the development of certain economic activities. The factors considered by Porter as determinants for the competitive advantage are grouped in four categories, the linkages between them being important as well

  10. Coal competitiveness?

    International Nuclear Information System (INIS)

    Rogeaux, B.

    2006-01-01

    Will coal electrical plants be more competitive in the coming years? Answering this one cannot be limited to merely comparing estimates based on reference electricity production costs. The competitiveness of coal will indeed depend on the final product marketed, as the MWhs are not equal: is the purpose to produce base, half-base MWh? Does the electrical equipment structure require flexible MWh (for instance in the event of significant intermittent renewable energy amounts), and therefore plants able to adjust their power rapidly? But the competitiveness of coal will also depend on many factors that will correct reference cost estimates: uncertainties, risks, externalities. These factors will need to be appreciated on a case by case basis. We introduce some of the reasoning used to better appreciate the future competitiveness of coal, and the main factors conditioning it in three contrasting regions of the world: Europe, USA, china. (author)

  11. Understanding competitiveness

    OpenAIRE

    CRESPO, Aranzazu; SEGURA-CAYUELA, Ruben

    2014-01-01

    Using firm level data, we analyze the factors that drive the evolution of the aggregate Unit Labor Costs – the main European competitiveness indicator – in France, Germany, Italy and Spain. The evolution of the aggregate Unit Labor Cost is not driven by the evolution of the firm level Unit Labor Costs, but rather by an important factor for the competitiveness of a country: the reallocation of resources among the firms of the economy. Using the methodology of Hsieh and Klenow (...

  12. REGIONAL COMPETITIVENESS

    OpenAIRE

    Krželj-Čolović, Zorica

    2015-01-01

    Individual city and regional authorities in many countries have themselves taken up the issue of “competitiveness” as part of their own economic development agendas: competitiveness has come to be regarded as critical for understanding and promoting local economic performance. Like their national counterparts, regional and city policy-makers have become preoccupied with knowing the relative competitive standing of their local economies compared with others, not just other regions and cities w...

  13. Characterization of Acute-Phase Humoral Immunity to Monkeypox: Use of Immunoglobulin M Enzyme-Linked Immunosorbent Assay for Detection of Monkeypox Infection during the 2003 North American Outbreak

    OpenAIRE

    Karem, Kevin L.; Reynolds, Mary; Braden, Zach; Lou, Gin; Bernard, Nikeva; Patton, Joanne; Damon, Inger K.

    2005-01-01

    A monkeypox outbreak occurred in the United States in 2003. Patient's sera were sent to the Centers for Disease Control and Prevention as a part of outbreak response measures. Clinical and epidemiologic information was abstracted from the case investigation forms. Serum samples from patients were tested by using an immunoglobulin M (IgM)-capture and an IgG enzyme-linked immunosorbent assay ELISA against Orthopoxvirus antigen. The detection of antiviral IgG and IgM antibodies and the kinetics ...

  14. Differentiation of foot-and-mouth disease virus-infected from vaccinated pigs by enzyme-linked immunosorbent assay using nonstructural protein 3AB as the antigen and application to an eradication program

    DEFF Research Database (Denmark)

    Chung, Wen Bin; Sørensen, Karl Johan; Liao, Pei Chih

    2002-01-01

    . Positive reactions were found in sera from fattening pigs and sows 16 weeks and 3.5 years postoutbreak, respectively. There was, however, no positive reaction in sows with at least 10 vaccinations. Maternally derived antibodies to the 3AB antigen persisted in piglets up to 13 weeks of age. A high......Baculovirus-expressed foot-and-mouth disease virus (FMDV) nonstructural protein 3AB was used as the antigen in an enzyme-linked immunosorbent assay. This assay allowed the differentiation of vaccinated from infected pigs. Serial studies were performed using sera collected from pigs in the field...

  15. A simple, high-throughput method to detect Plasmodium falciparum single nucleotide polymorphisms in the dihydrofolate reductase, dihydropteroate synthase, and P. falciparum chloroquine resistance transporter genes using polymerase chain reaction- and enzyme-linked immunosorbent

    DEFF Research Database (Denmark)

    Alifrangis, Michael; Enosse, Sonia; Pearce, Richard

    2005-01-01

    . However, to be a practical tool in the surveillance of drug resistance, simpler methods for high-throughput haplotyping are warranted. Here we describe a quick and simple technique that detects dhfr, dhps, and Pfcrt SNPs using polymerase chain reaction (PCR)- and enzyme-linked immunosorbent assay (ELISA...... the SNPs of dhfr, dhps, and Pfcrt with high specificity. The SSOP-ELISA compared well with a standard PCR-restriction fragment length polymorphism procedure, and gave identical positive results in more than 90% of the P. falciparum slide-positive samples tested. The SSOP-ELISA of all dhfr, dhps, or Pfcrt...

  16. Serum antibodies from a subset of horses positive for babesia caballi by competitive enzyme-linked immunosorbent assay demonstrate a protein recognition pattern that is not consistent with infection

    Science.gov (United States)

    Tick-borne pathogens that cause persistent infection are of major concern to the livestock industry because of transmission risk from persistently infected animals and the potential economic losses they pose. The recent re-emergence of Theileria equi in the U.S. prompted widespread national surveill...

  17. CONCEPTUAL APPROACH OF COMPETITIVENESS AND INTERDEPENDENCE BETWEEN COMPETITION AND COMPETITIVENESS

    Directory of Open Access Journals (Sweden)

    Tatiana GUTIUM

    2017-11-01

    Full Text Available This article is devoted to analysis of interdependence and correlation between competition and competitiveness, and competition’s consequences. The author analysed some authors’ visions on competitiveness, and common features between theories of competition and competitiveness. Using the synthetic indicator elaborated by author has been evaluated the competitiveness of domestic goods on the internal and external market. At the end of this article, the author has developed proposals to increase competitiveness.

  18. Subcontract Competition.

    Science.gov (United States)

    1982-11-01

    DRCPM- ROL USA Missile Command, ATTN: DRCPM-VI Armor Training Devices, ATTN: DRCPM-AR 3 APRO 82-11 FINAL SUBCONTRACT COMPETITION by Wayne V. Zabel Charles...A. Correia "I S The pronouns "he," "his," and "him," when used in this publication, represent both the masculine and feminine genders unless... advertising or by negotiation, shall be made on a competitive basis to the maximum practicable extent." Armed Services Procurement Regul-tion Manual

  19. Validation of a new enzyme-linked immunosorbent assay to detect the triggering proteins and peptides for celiac disease: interlaboratory study.

    Science.gov (United States)

    Mujico, Jorge R; Dekking, Liesbeth; Kooy-Winkelaar, Yvonne; Verheijen, Ron; van Wichen, Piet; Streppel, Lucia; Sajic, Nermin; Drijfhout, Jan W; Koning, Frits

    2012-01-01

    The performance of Gluten-Tec (EuroProxima, Arnhem, The Netherlands) was tested through an interlaboratory study in accordance with AOAC guidelines. Gluten-Tec is a competitive ELISA that detects an immunostimulatory epitope of a-gliadin in dietary food for celiacs. Fifteen laboratories, representing 14 different countries, announced their interest in taking part in this study. Of the 12 laboratories that sent the results within the established timeframe, two submitted inappropriate standard curves and were excluded from the statistical analysis. Four different food matrixes (rice-based baby food, maize bread, chocolate cake mix, and beer) were selected for preparing the test samples. Two gliadin extraction procedures were used: the conventional 60% ethanol, and a new method based on the reducing reagent dithiothreitol. The 38 samples (19 blind duplicates) tested in this study were prepared by diluting the different extracts in order to cover a wide range of gliadin levels. Both sample extraction and dilution were performed by EuroProxima; the present interlaboratory study was focused only on testing the ELISA part of the Gluten-Tec kit protocol. Repeatability values (within-laboratory variance), expressed as RSD(r) ranged from 6.2 to 25.7%, while reproducibility values (interlaboratory variance), expressed as RSD(R), ranged from 10.6 to 45.9%. Both statistical parameters were in the acceptable range of ELISAs under these conditions, and the method will be presented to the Codex Alimentarius as a preferred method for gluten analysis.

  20. Development of an enzyme-linked immunosorbent assay (ELISA)-like fluorescence assay to investigate the interactions of glycosaminoglycans to cells

    International Nuclear Information System (INIS)

    Boucas, Rodrigo Ippolito; Trindade, Edvaldo S.; Tersariol, Ivarne L.S.; Dietrich, Carl P.; Nader, Helena B.

    2008-01-01

    Sulfated glycosaminoglycans were labeled with biotin to study their interaction with cells in culture. Thus, heparin, heparan sulfate, chondroitin 4-sulfate, chondroitin 6-sulfate and dermatan sulfate were labeled using biotin-hydrazide, under different conditions. The structural characteristics of the biotinylated products were determined by chemical (molar ratios of hexosamine, uronic acid, sulfate and biotin) and enzymatic methods (susceptibility to degradation by chondroitinases and heparitinases). The binding of biotinylated glycosaminoglycans was investigated both in endothelial and smooth muscle cells in culture, using a novel time resolved fluorometric method based on interaction of europium-labeled streptavidin with the biotin covalently linked to the compounds. The interactions of glycosaminoglycans were saturable and number of binding sites could be obtained for each individual compound. The apparent dissociation constant varied among the different glycosaminoglycans and between the two cell lines. The interactions of the biotinylated glycosaminoglycans with the cells were also evaluated using confocal microscopy. We propose a convenient and reliable method for the preparation of biotinylated glycosaminoglycans, as well as a sensitive non-competitive fluorescence-based assay for studies of the interactions and binding of these compounds to cells in culture

  1. Case competitions

    DEFF Research Database (Denmark)

    Schjoldager, Anne Gram

    2009-01-01

    The paper presents and discusses a teaching project with case competitions for MA students of specialised translation at the Aarhus School of Business, Aarhus University. Drawing on a series of online questionnaires, the paper ascertains how the project was evaluated by the participating students...

  2. Sport competitions in Antique Chersoneses.

    Directory of Open Access Journals (Sweden)

    Moutiev A.V.

    2011-12-01

    Full Text Available It is examined the content of physical education in Chersoneses in the ancient period. It is shown the participation of citizens in the Chersoneses competitions at various levels. Stressed the importance of physical culture, sports, sports training, organizing and conducting athletic competitions. Show the direction of physical education of youth, training for local and Panhellenic competitions, military service. The role of the teacher of gymnastics in physical education students in public schools. It is noted that the study involved in Chersoneses pedagogical methods and techniques. It is established that the citizens of Chersoneses actively participated in Panhellenic competitions and they became the victors.

  3. The “Direct Care of Health” and the Ethics as Expression of Specific Professionals Competition in the Superior Technician in Infirmary in Ecuador (TSE)

    OpenAIRE

    Lic. Lenny Mariscal-San Martin; Lic. Víctor Rodríguez-Medrano

    2015-01-01

    The gratuidad of the Education Superior Public Ecuadorian offers possibilities of social character and opportunities to the Superior Technician of Infirmary (TSE). nevertheless, the Technological Institute Bolivariano in Technology of Guayaquil yearns to form technical professionals that contribute an academic excellence, able to show competitions in its practical performance, fundamentally, in the care of the health of the patients, supported in scientific bases and necessary foundations for...

  4. Development of an enzyme-linked immunosorbent assay for detection of chicken osteocalcin and its use in evaluation of perch effects on bone remodeling in caged White Leghorns.

    Science.gov (United States)

    Jiang, S; Cheng, H W; Hester, P Y; Hou, J-F

    2013-08-01

    Osteocalcin (OC) is a sensitive biochemical marker for evaluating bone turnover in mammals. The role of avian OC is less clear because of the need for a chicken assay. Our objectives were to develop an assay using indirect competitive ELISA for detecting chicken serum OC and use the assay to examine the effects of perches on bone remodeling in caged hens. Anti-chicken OC polyclonal antibody was produced by immunization of rabbits with a recombinant OC from Escherichia coli. Chicken OC extracted from bone was used as a coated protein, and purified chicken OC was used for calibration. The limit of detection of the developed OC ELISA was 0.13 ng/mL. The intra- and interassay CV were hens housed in conventional cages with or without perches. Serum samples were collected from 71-wk-old White Leghorn hens subjected to 4 treatments. Treatment 1 was control chickens that never had access to perches during their life cycle. Treatment 2 chickens had perches during the pullet phase (0 to 16.9 wk of age), whereas treatment 3 chickens had perches only during the egg-laying phase of the life cycle (17 to 71 wk of age). Treatment 4 chickens always had access to perches (0 to 71 wk of age). Correlation between the 2 assays was 0.62 (P hens with perch access had higher concentrations of serum OC than hens without perches during egg laying (P = 0.04). Pullet access to perches did not affect serum OC levels in 71-wk-old hens (P = 0.15). In conclusion, a chicken OC ELISA has been validated that is sensitive and accurate with adequate discriminatory power for measuring bone remodeling in chickens.

  5. EDITORIAL: Physics competitions Physics competitions

    Science.gov (United States)

    Jordens, H.; Mathelitsch, L.

    2010-07-01

    This editorial opens the second special section on physics competitions in European Journal of Physics. In the first section last year, we asked for feedback on the idea of such a section and on the content of the articles. We received no answer whatsoever, which can be interpreted in two ways: the section is not interesting enough to raise motivation for feedback, or the reader is satisfied. Having no indication which scenario is the correct one, we are optimistic and favour the second. The section at hand contains three articles. Again, as last year, the organizer of the annual Olympiad reports on tasks and outcomes of this competition. The Olympiad took place in Merida, Mexico, and was by far the largest event with 316 contestants from 68 countries. Again, the predominance of Asian/Chinese students was manifest, showing how serious the training is taken by both their authorities and students. Unfortunately, the winners of the last International Young Physicists' Tournament (IYPT), the team from Korea, did not accept the offer to report on their prize-winning contribution. We are thankful that two students from Austria, who achieved second place with their team, took over and reported on the task which they presented in the finals of the competition. It connects the fields of sport and physics and explains a special move in skateboarding. The third contribution introduces a different competition, 'International Conference of Young Scientists'. On one hand, as in the Olympiad, it addresses individuals, not teams. On the other, as in the IYPT, students have several months to prepare and also the quality of the presentation is an important element of the judgment. In fact, this competition comes closer to real scientific research compared to the other events. Finally and again, we hope that this section will serve several purposes: To show the competitions as a very important tool in the support of gifted students. To raise awareness amongst university teachers, and

  6. Logo competition

    CERN Multimedia

    Staff Association

    2013-01-01

    Award of the prizes The price ceremony for the Staff Association’s new logo competition which took place on Friday 1st March at 5 p.m. was a big success. The first prize, an Ezee Suisse electric bike, was won by Paulo Rios, from Portugal. In his absence, the bike was handed to his brother Vitor. The other five winners of the competition also received their prize: Go Sport vouchers. A peize draw was then organized to award 22 other participants with prizes offered by our commercial partners (Aquaparc, BCGE, L’Occitane, Passeport Gourmand, Sephora, Theater La Comédie de Genève), whom we would like to warmly thank. After all prices were distributed the evening continued with discussions around a friendly drink.

  7. Measuring competitiveness

    OpenAIRE

    J. Peter Neary

    2005-01-01

    An earlier version was presented at the Conference on Macroeconomic Perspectives in Honour of Brendan M. Walsh, held at University College Dublin on 7 October, 2005 This paper reviews alternative approaches to measuring an economy?s cost competitiveness and proposes some new measures inspired by the economic theory of index numbers. The indices provide a theoretical benchmark for estimated real effective exchange rates, but differ from standard measures in that they are based on marginal r...

  8. Optimal Competition : A Benchmark for Competition Policy

    NARCIS (Netherlands)

    Boone, J.

    2003-01-01

    This paper introduces optimal competition: the best form of competition in an industry that a competition authority can achieve under the information constraint that it cannot observe firms' effciency levels.We show that the optimal competition outcome in an industry becomes more competitive as more

  9. The serologic response to Salmonella enteritidis and Salmonella typhimurium in experimentally infected chickens, followed by an indirect lipopolysaccharide enzyme-linked immunosorbent assay and bacteriologic examinations through a one-year period

    DEFF Research Database (Denmark)

    Skov, M.N.; Feld, Niels Christian; Carstensen, B.

    2002-01-01

    uninfected as controls. The groups were monitored bacteriologically by examination of cloacal swabs and organs and serologically by examination of serum and egg yolk by a lipopolysaccharide enzyme-linked immunosorbent assay throughout the period. Within the first week, 100% of birds in both infected groups...... at the onset of egg production. For both S. typhimurium and S. enteritidis, positive bacteriologic cultures were obtained by sampling from internal organs at the end of the experiment, more than 1 yr from the time of infection. At the age of 6-7 wk, 50% of the chickens in the two infected groups showed...... a measurable serologic response in serum samples. The response persisted throughout the study in both serum and egg yell, samples. The inclusion of serologic methods is a valuable additional tool in the detection of salmonella in poultry, but serology should be used in conjunction with bacteriologic methods...

  10. Serodiagnosis of Leishmania donovani infections: assessment of enzyme-linked immunosorbent assays using recombinant L. donovani gene B protein (GBP) and a peptide sequence of L. donovani GBP

    DEFF Research Database (Denmark)

    Jensen, A T; Gasim, S; Moller, T

    1999-01-01

    The repetitive sequence of Leishmania major gene B protein (GBP) has previously been shown to be a useful tool in the diagnosis of cutaneous leishmaniasis (CL). Here, we have assessed enzyme-linked immunosorbent assays (ELISAs) using recombinant L. donovani GBP (rGBP) and a peptide sequence of L....... donovani GBP (GBPP) in the diagnosis of L. donovani infections in Sudan. The sensitivity of the rGBP ELISA in diagnosing visceral leishmaniasis (VL) and post kala-azar dermal leishmaniasis (PKDL) was 92% and 93%, respectively. In contrast, the sensitivity of the GBPP ELISA was 55% for VL and 63% for PKDL...... for malaria but free of leishmaniasis was negative in both assays....

  11. Inhibition of key enzymes linked to type 2 diabetes and sodium nitroprusside-induced lipid peroxidation in rat pancreas by water-extractable phytochemicals from unripe pawpaw fruit (Carica papaya).

    Science.gov (United States)

    Oboh, Ganiyu; Olabiyi, Ayodeji A; Akinyemi, Ayodele J; Ademiluyi, Adedayo O

    2014-02-01

    Various parts of unripe pawpaw (Carica papaya Linn) fruit have been reportedly used for the management or treatment of diabetes mellitus in folklore medicine. Therefore, the present study sought to investigate the inhibitory effects of the aqueous extract of different parts of unripe pawpaw fruit on key enzymes linked to type 2 diabetes (α-amylase and α-glucosidase) and sodium nitroprusside (SNP)-induced lipid peroxidation in rat pancreas in vitro. The aqueous extracts of the unripe pawpaw (C. papaya) fruit parts were prepared (1:20 w/v) and the ability of the extracts to inhibit α-amylase, α-glucosidase and SNP-induced lipid peroxidation in rat pancreas in vitro was investigated. The results revealed that all the extracts inhibited α-amylase (IC50=0.87-1.11 mg/mL), α-glucosidase (IC50=1.76-2.64 mg/mL) and SNP-induced lipid peroxidation (IC50=1.99-2.42 mg/mL) in a dose-dependent manner. However, combination of the flesh, seed and peel in equal amounts had the highest inhibitory effect on α-amylase and α-glucosidase activities. Strong inhibitory activities of the unripe pawpaw fruit against key enzymes linked to type 2 diabetes and SNP-induced lipid peroxidation in rat pancreas could be part of the mechanism by which unripe pawpaw is used in the management/prevention of diabetes mellitus in folk medicine. However, combining the unripe pawpaw fruit parts in equal amounts exhibited synergistic properties on α-amylase and α-glucosidase inhibitory activities.

  12. The Combined Utility of Ex vivo IFN-γ Release Enzyme-Linked ImmunoSpot Assay and In vivo Skin Testing in Patients With Antibiotic-Associated Severe Cutaneous Adverse Reactions.

    Science.gov (United States)

    Trubiano, Jason A; Strautins, Kaija; Redwood, Alec J; Pavlos, Rebecca; Konvinse, Katherine C; Aung, Ar Kar; Slavin, Monica A; Thursky, Karin A; Grayson, M Lindsay; Phillips, Elizabeth J

    2017-10-31

    For severe cutaneous adverse reactions (SCARs) associated with multiple antibiotics dosed concurrently, clinical causality is challenging and diagnostic approaches are limited, leading to constricted future antibiotic choices. To examine the combined utility of in vivo and ex vivo diagnostic approaches at assigning drug causality in a cohort of patients with antibiotic-associated (AA)-SCARs. Patients with AA-SCARs were prospectively recruited between April 2015 and February 2017. In vivo testing (patch testing or delayed intradermal testing) was performed to the implicated antibiotic(s) at the highest nonirritating concentration and read at 24 hours through 1 week. Ex vivo testing used patient peripheral blood mononuclear cells (PBMCs) stimulated with a range of pharmacologically relevant concentrations of implicated antibiotics to measure dose-dependent IFN-γ release from CD4+ and CD8+ T cells via an enzyme-linked immunoSpot assay. In 19 patients with AA-SCARs, combined in vivo and ex vivo testing assigned antibiotic causality in 15 (79%) patients. Ten patients (53%) with AA-SCARs were positive on IFN-γ release enzyme-linked immunoSpot assay, with an overall reported sensitivity of 52% (95% CI, 29-76) and specificity of 100% (95% CI, 79-100), with improved sensitivity noted in acute (within 1 day to 6 weeks after SCAR onset) testing (75%) and in patients with higher phenotypic scores (59%). There was increased use of narrow-spectrum beta-lactams and antibiotics from within the implicated class following testing in patients with a positive ex vivo or in vivo test result. We demonstrate the potential utility of combined in vivo and ex vivo testing in patients with AA-SCARs to assign drug causality with high specificity. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  13. International Competitiveness

    OpenAIRE

    Jan Fagerberg

    1988-01-01

    This paper develops and tests a model of differing trends in international competitiveness and economic growth across countries. The model relates the development of market shares at home and abroad to three sets of factors: the ability to compete in technology, the ability to compete in delivery(capacity) and the ability to compete in price. The test, using data for 15 OECD countries for the period 1961-1983, shows that in the medium and long run, factors related to technology and capacity a...

  14. EDITORIAL: Physics competitions Physics competitions

    Science.gov (United States)

    Jordens, H.; Mathelitsch, L.

    2011-07-01

    International tests on competences, such as TIMSS or PISA, and knowledge of young students have revealed low average scores in many countries, often unexpectedly. One effective measure to increase the average standard of a population is to bring the last third of the group to a higher level. Therefore, many nations put some effort into this activity. This brings the danger that not enough attention is paid to students at the other end, those who are talented. Indeed, it is a very difficult task for a teacher to support the less able and at the same time challenge the gifted students, to lead them to the limits of their abilities and provide for a smooth transition to university study. Physics competitions have been proven to fulfil these last demands to a large degree, and therefore are an important additional and, to some extent, complementary tool for the promotion of talented students. This third special section on physics competitions in European Journal of Physics contains three papers, each dealing with a different form of science contest. The first continues the series of presentations of tasks performed at the International Young Physicists' Tournament, which was held in Vienna in 2011. First place went to the team from Singapore, and they have put their investigation on vertical oscillations of coupled magnets into written form (not required by the tournament, where an oral presentation and a defence and discussion are the central aspects). Their paper shows how rich in physics this problem is, and what level of solutions high-school students can already achieve. Sadly, those responsible for the organization of last year's International Physics Olympiad did not provide us with a report on this competition. This is unfortunate, since the Olympiad in Zagreb was very successful and, in particular, the experimental tasks were creative and demanding. Very similar to the aims and the execution of the Physics Olympiad is the International Olympiad on Astronomy

  15. The future of competitions

    DEFF Research Database (Denmark)

    Bates, Gary; Jensen, Boris Brorman; Miessen, Markus

    2010-01-01

    We wanted to explore the potential of the competition. The question we asked ourselves was if the competition can generate new, relevant and critical ideas within architecture? We organized an idea competition about the architectural competition.......We wanted to explore the potential of the competition. The question we asked ourselves was if the competition can generate new, relevant and critical ideas within architecture? We organized an idea competition about the architectural competition....

  16. Fiscal competition and regional differentiation

    OpenAIRE

    Justman, Moshe; Thisse, Jacques-François; Van Ypersele, Tanguy

    2001-01-01

    Regions can benefit by offering infrastructure services that are differentiated. Competition between regions over potential investors is then less direct, allowing them to realize greater benefits from external investors. The two polar cases of full and incomplete information about investors' needs are studied. In both cases, there is regional differentiation. However, fiscal competition is efficient in the former case but not in the latter. Finally, it is shown that free entry in the loc...

  17. Competitiveness Evaluation of Slovenian Economy

    OpenAIRE

    Art Kovacic

    2007-01-01

    Evaluation of competitiveness became an important instrument for balancing the development process of the economy. For Slovenia it is important tool for policy creation. Benchmarking with more developed countries shows us the right directions of development process. Competitiveness can be analysed from different sides. Existed studies have focused on several different analytical levels: product, firm, industry cluster, region and nation. The most successful economies are raising the skill con...

  18. Impact of EU Council Directive 99/74/EC 'welfare of laying hens' on the competitiveness of the EU egg industry.

    NARCIS (Netherlands)

    Horne, van P.L.M.; Bondt, N.

    2003-01-01

    Because of animal welfare concerns in the EU, from 2012 only enriched cages will be allowed for the housing of laying hens (Council Directive 1999/74/EC). Production in enriched cages will increase the production cost of eggs. At the same time the World Trade Organisation (WTO) has launched a new

  19. Influence of Anti-FloR Antibody on Florfenicol Accumulation in Florfenicol-Resistant Escherichia coli and Enzyme-Linked Immunosorbent Assay for Detection of Florfenicol-Resistant E. coli Isolates

    Science.gov (United States)

    Wu, Beibei; Xia, Chun; Du, Xiangdang; Cao, Xingyuan; Shen, Jianzhong

    2006-01-01

    To detect florfenicol-resistant Escherichia coli isolates by enzyme-linked immunosorbent assay (ELISA), anti-FloR1 antibodies were produced in mice using a recombinant glutathione S-transferase (GST)-FloR1 protein, which was expressed in a prokaryote expression system, as the antigen. The specificity of the murine anti-GST-FloR1 antibody and its influence on florfenicol accumulation in florfenicol-resistant isolates were investigated using Western blotting and high-performance liquid chromatography, respectively. Western blotting using the anti-FloR1 antibody showed specific binding of the antibody to the florfenicol-resistant FloR protein. Preincubation of florfenicol-resistant strains with the antibody significantly increased the intracellular accumulation of florfenicol and enhanced the bacterial susceptibility to florfenicol, suggesting that antibody binding to the FloR protein inhibited the activity of the efflux protein conferred by the floR gene. Analyses of florfenicol-resistant and -sensitive isolates by ELISA using the anti-FloR1 antibody showed good correlation between FloR protein expression and the floR genotype. The anti-FloR1 antibody-based ELISA is a useful tool for the detection of florfenicol-resistant bacteria harboring the floR gene. PMID:16455887

  20. Conductive carbon nanoparticles-based electrochemical immunosensor with enhanced sensitivity for alpha-fetoprotein using irregular-shaped gold nanoparticles-labeled enzyme-linked antibodies as signal improvement.

    Science.gov (United States)

    Tang, Juan; Su, Biling; Tang, Dianping; Chen, Guonan

    2010-08-15

    A new electrochemical immunoassay protocol for sensitive detection of alpha-fetoprotein (AFP, as a model) is designed using carbon nanoparticles (CNPs)-functionalized biomimetic interface as immunosensing probe and irregular-shaped gold nanoparticles (ISNGs)-labeled horseradish peroxidase-anti-AFP conjugates (HRP-anti-AFP-ISNG) as trace label. The low-toxic and high-conductive CNPs provided a high capacity nanoparticulate immobilization surface and a facile pathway for electron transfer. In comparison with conventional label methods, i.e. spherical gold nanoparticles-labeled HRP-anti-AFP and HRP-labeled anti-AFP, the electrochemical immunosensor using HRP-anti-AFP-ISNGs as trace labels exhibited high bioelectrocatalytic response toward enzyme substrate and a wide dynamic range from 0.02 to 4.0 ng/mL with a low detection limit of 10 pg/mL toward AFP (at 3sigma). The developed immunoassay method showed good selectivity and acceptable reproducibility. Clinical serum samples with various AFP concentrations were evaluated by using the electrochemical immunosensor and the referenced enzyme-linked immunosorbent assay (ELISA), respectively, and received in good accordance with results obtained from these two methods. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Expression of Leptin and Visfatin in Gingival Tissues of Chronic Periodontitis With and Without Type 2 Diabetes Mellitus: A Study Using Enzyme-Linked Immunosorbent Assay and Real-Time Polymerase Chain Reaction.

    Science.gov (United States)

    Ghallab, Noha A; Amr, Eman M; Shaker, Olfat G

    2015-07-01

    The aim of this study is to investigate the protein and gene expression of leptin and visfatin in gingival tissue from patients with chronic periodontitis (CP), patients with CP and type 2 diabetes mellitus (T2DM), and healthy individuals. The study includes 50 individuals: 10 healthy individuals, 20 patients with CP, and 20 patients with CP and T2DM. Plaque index, gingival index, probing depth, and clinical attachment loss were measured, and gingival biopsies were obtained. Leptin and visfatin protein expression in gingival tissues was determined using enzyme-linked immunosorbent assay, and messenger RNA (mRNA) expression was measured via real-time polymerase chain reaction. The highest leptin mRNA and protein expression was observed in the control group and was significantly (P ≤0.05) different from the CP and CP+T2DM groups. Gingival tissues from patients with CP and T2DM had a significant increase in visfatin and a decrease in leptin gene and protein expression (P <0.05) compared with both controls and patients with CP. Expression of leptin and visfatin in the gingival tissues suggests a possible role for these adipokines in the pathogenesis of CP and T2DM.

  2. Fabrication of paper devices via laser-heating-wax-printing for high-tech enzyme-linked immunosorbent assays with low-tech pen-type pH meter readout.

    Science.gov (United States)

    Le, Shangwang; Zhou, Hui; Nie, Jinfang; Cao, Chaohong; Yang, Jiani; Pan, Hongcheng; Li, Jianping; Zhang, Yun

    2017-01-26

    In this work, a new method named laser-heating-wax-printing (LHWP) is described to fabricate paper devices for developing sensitive, affordable, user-friendly paper-based enzyme-linked immunosorbent assays (P-ELISAs) that initially use common pen-type pH meters for portable, quantitative readout. The LHWP enables a rapid patterning of wax in paper via one step of heating the wax layer coated on the paper surface using a mini-type CO 2 laser machine. Wax-patterned paper microzones created in this way are utilized to conduct the pen-type pH meter-based P-ELISAs with enzyme-loaded SiO 2 microbeads for highly efficient signal amplification of each antibody-antigen binding event. The results show that this new P-ELISA system is quantitatively sensitive to the concentrations of a model protein analyte in buffer samples ranging from 12.5 to 200 pg mL -1 , with a limit of detection of ca. 7.5 pg mL -1 (3σ). Moreover, the satisfactory recovery results of assaying several human serum samples validate its feasibility for practical applications.

  3. Analysis of matrix metalloproteinase-8 levels in gingival crevicular fluid and whole mouth fluid among smokers and nonsmokers using enzyme-linked immune-sorbent assay and a novel chair-side test.

    Science.gov (United States)

    Akbari, Ghousia; Prabhuji, Munivenkatappa Lakshmaiah Venkatesh; Karthikeyan, Bangalore Vardhan; Raghunatha, Kanugondappa; Narayanan, Roopalakshmi

    2015-01-01

    To indigenously prepare a chair-side test kit for investigating and comparing the matrix metalloproteinase (MMP)-8 levels in gingival crevicular fluid (GCF) and saliva in patients with healthy periodontium, gingivitis and chronic periodontitis in smokers and nonsmokers. To validate the diagnostic accuracy of indigenously prepared chair-side test against enzyme-linked immune-sorbent assay (ELISA). Furthermore, to assess the effect of nonsurgical periodontal therapy (NSPT) on the levels of MMP-8 in GCF and saliva among the test groups. GCF and saliva were collected from 250 subjects. The study population were divided into five groups; health periodontium-nonsmokers (Group 1; n = 50), chronic gingivitis-nonsmokers (Group 2; n = 50), chronic periodontitis-nonsmokers (Group 3; n = 50), chronic gingivitis-smokers (Group 4; n = 50), chronic periodontitis-smokers (Group 5; n = 50). A chair-side test kit was indigenously prepared using polyclonal antibodies (principle of immunochromatography) to detect the MMP-8 levels, and it was validated against ELISA at baseline and 3 months after NSPT. The chair-side test detected MMP-8 levels with a sensitivity and specificity in accordance with ELISA. MMP-8 levels at baseline were higher in Group 2 and Group 3 as compared to controls (P chair-side test detected MMP-8 levels accurately making it a viable chair side diagnostic tool. It was effective for early diagnosis of the periodontal disease among high-risk population such as smokers.

  4. Enzyme-Linked Immunosorbent Assay Based on Soluble Promastigote Antigen Detects Immunoglobulin M (IgM) and IgG Antibodies in Sera from Cases of Visceral and Cutaneous Leishmaniasis

    Science.gov (United States)

    Ryan, Jeffrey R.; Smithyman, Anthony M.; Rajasekariah, G-Halli; Hochberg, Lisa; Stiteler, John M.; Martin, Samuel K.

    2002-01-01

    Leishmaniasis causes significant morbidity and mortality in areas where it is endemic. In areas where it is nonendemic, global travel and increased incidence of the disease in human immunodeficiency virus and intravenous-drug user populations are also causes for concern. The unavailability of rapid and reliable tests for diagnosis of the various leishmaniases makes patient management difficult. We have developed an enzyme-linked immunosorbent assay (ELISA) that can detect immunoglobulin M (IgM) and IgG antibodies in patients with visceral and cutaneous leishmaniasis. These practical assays are based on soluble antigens from promastigotes cultivated in a protein-free medium. In preliminary studies, 129 visceral (Brazil, Italy, North Africa, and Nepal) and 143 cutaneous (Brazil) leishmaniasis patients with controls were tested. Overall, the tests showed a sensitivity of 95.1%. In addition, the ELISA correctly identified 42 sera from Brazilian dogs with canine leishmaniasis and 10 healthy controls. Serological tests for the various clinical manifestations of leishmaniasis could be useful epidemiological and patient management tools in populations of areas of endemicity and nonendemicity. PMID:11880434

  5. A reliable screening test to identify adult carriers of the (--SEA) alpha zero-thalassemia deletion. Detection of embryonic zeta-globin chains by enzyme-linked immunosorbent assay.

    Science.gov (United States)

    Lafferty, J D; Crowther, M A; Waye, J S; Chui, D H

    2000-12-01

    Homozygous (--SEA) alpha zero-thalassemia deletion, the cause of up to 80% of fetal hydrops in Southeast Asia, is encountered in many other countries. Heterozygous carrier rates of the deletion in Southeast Asian populations range from 4% to 14%. The laboratory screening for adult carriers of (--SEA) and other alpha zero-thalassemia deletions currently rests primarily with microscopic detection of hemoglobin H inclusion bodies within erythrocytes (Hb H screen). This test is laborious and observer dependent and has poor sensitivity. We assessed a colorimetric enzyme-linked immunosorbent assay (ELISA) to detect embryonic zeta-globin chains in adult hemolysates as an alternative to detect (--SEA) alpha zero-thalassemia deletion carriers. Blood samples from 221 adults with a mean corpuscular volume less than 80 micron 3 (80 fL) were studied prospectively by currently accepted hemoglobin screening tests and ELISA. Suspected cases of alpha-thalassemia were confirmed by DNA-based diagnostics. ELISA was highly sensitive (1.0) and specific (0.94) for the detection of adult carriers of (--SEA) alpha zero-thalassemia deletion. The hemoglobin H screen had a sensitivity of 0.47 and specificity of 0.99. The zeta-globin ELISA proved simple to perform, rapid, and applicable to high volume or population-based screening programs.

  6. Enzyme linked immunosorbent assay (ELISA for the detection of IgG, IgM, IgE and IgA against Cysticercus cellulosae in cerebrospinal fluid of patients with neurocysticercosis

    Directory of Open Access Journals (Sweden)

    Odashima Newton Satoru

    2002-01-01

    Full Text Available The objective of this study was to analyze different immunoglobulins classes (IgG, IgM, IgE and IgA against Cysticercus cellulosae in the cerebrospinal fluid (CSF, through enzyme linked immunosorbent assay (ELISA, correlating them to clinical and tomographic profiles in patients with neurocysticercosis (NCC. Eighty-five specimens of CSF were obtained from 43 cases with NCC (26 with the active form and 17 with the inactive form and from 42 patients with other neurological diseases. The inactive form of NCC presented a profile in CSF similar to the group without NCC. The active form of NCC presented elevation of specific immunoglobulins (IgG, IgM, IgE, and IgA in decreasing order, with the highest values being detected among the cases with intraventricular cysts, or with inflammation signs in CSF or in those with multiple clinical manifestations. The highest sensitivity and specificity were obtained with ELISA-IgG (88.5% and 93.2%, respectively. This study confirmed the importance of ELISA in the immunologic diagnosis of NCC.

  7. Comparison of immunofluorescence and enzyme-linked immunosorbent assay and immunoglobulin G avidity techniques for screening of anti: Toxoplasma antibodies among single serum sample pregnant women in Tabriz, Iran

    Directory of Open Access Journals (Sweden)

    Mehrangiz Rajaii

    2015-01-01

    Full Text Available Background: Congenital toxoplasmosis is that pregnant women acquire the infection during gestation; diagnosis of the acute infection during pregnancy is a complex subject of maternal toxoplasmosis. Thus, the presence of immunoglobulin G (IgG and/or IgM Toxoplasma antibodies in a single serum sample drawn during gestation cannot be used to define whether the infection was recently acquired or chronic. Materials and Methods: At this cross-sectional descriptive study, sera of 391 pregnant women examined and compared. They were in an age range of 21-35 years, referred by gynecologists and infectious disease specialists, during March 2012-April 2013. They have referred, 215 (54.98%, 102 (26%, 74 (18.92% in the first, second and third trimesters of gestation, respectively. For each of them, a questionnaire was completed and serum samples were prepared in an equal condition, examined according to the procedures of indirect immunofluorescence (IIF, enzyme-linked immunosorbent assay (ELISA and IgG Avidity techniques. Results: We have found 111 (28.38% seronegative and 280 (71.61% seropositive cases by IIF and 124 (31.70% seronegative, 267 (68.28% seropositive cases by ELISA. The IgG avidity test confirmed 45 (69.23% and 7 (10.76% doubtful cases of IgM test in IIF and ELISA techniques. Conclusions: This study highlights how to manage pregnant women with toxoplasmosis, especially in a single serum sample condition.

  8. Evaluation of two Taenia solium cysticercal antigenic preparations (vesicular fluid and a glycoprotein fraction with affinity for lentil lectin for the immunodiagnosis of neurocysticercosis by enzyme-linked immunosorbent assay (ELISA

    Directory of Open Access Journals (Sweden)

    Lisandra Akemi Suzuki

    2011-06-01

    Full Text Available OBJECTIVE: To evaluate the performance of two antigenic preparations (vesicular fluid - VF and a glycoprotein fraction, LLa-Gp fraction, purified from a whole parasite extract by lentil lectin affinity chromatography from Taenia solium cysticerci for the immunodiagnosis of neurocysticercosis. METHOD: Fifty-six cerebrospinal fluid (CSF samples (22 from patients with neurocysticercosis and 34 from patients with other neurological disorders and 57 serum samples (22 from patients with neurocysticercosis, 18 from patients with other infections and 17 from presumably healthy persons were assayed for anticysticercal IgG antibodies with an enzyme-linked immunosorbent assay (ELISA. RESULTS: The VF ELISA showed 100% sensitivity and specificity in CSF and serum samples, whereas the sensitivity and specificity of the LLa-Gp ELISA were, respectively, 90.9% and 97.1%, with the CSF samples and 95.5% and 100% with serum samples. There was no significant difference in the sensitivity and specificity of the two antigenic preparations used to screen CSF and serum samples. CONCLUSION: Considering the complexity and high cost of obtaining the LLa-Gp fraction, VF could be more suitable for screening specific antibodies by ELISA in CSF and serum samples from patients with neurocysticercosis.

  9. Comparison of bacterial culture, polymerase chain reaction, and a mix-enzyme-linked immunosorbent assay for the detection of Salmonella status in grow-to-finish pigs in western Canada with a Bayesian approach.

    Science.gov (United States)

    Wilkins, Wendy; Waldner, Cheryl; Rajić, Andrijana; McFall, Margaret; Chow, Eva; Muckle, Anne

    2011-10-01

    Among grow-to-finish pigs from 10 herds in Alberta and Saskatchewan, 23 (16%) of 144 fecal samples were culture-positive and 40 (28%) of 144 pigs were seropositive for Salmonella. With a Bayesian model specifying dependence between the 2 tests, the sensitivity (Se) of culture and real-time polymerase chain reaction (RT-PCR) was 79% to 86%, depending on the cut-off value for the enzyme-linked immunosorbent assay (ELISA). Culture specificity (Sp) was assumed to be 100%; RT-PCR Sp was found to be 94%. The ELISA Se was 76% and 51% at optical density cut-off values ≥ 20% and ≥ 40%, respectively; the Sp was 94% at each cut-off value. The model showed some sensitivity to ELISA prior information, the ELISA Se being approximately 8% lower when informative prior information was specified in the model. When there was no adjustment for dependence between culture and RT-PCR, the posterior estimates for both culture and RT-PCR Se were 11% higher than with the conditional-dependence model and had considerably narrower probability intervals, which suggests that correlation between culture and PCR is important and should be adjusted for in future studies.

  10. Direct Comparison of the Histidine-rich Protein-2 Enzyme-linked Immunosorbent Assay (HRP-2 ELISA) and Malaria SYBR Green I Fluorescence (MSF) Drug Sensitivity Tests in Plasmodium falciparum Reference Clones and Fresh ex vivo Field Isolates from Cambodia

    Science.gov (United States)

    2013-07-12

    mefloquine (Pearson r = 0.85-0.99 for reference clones and 0.56-0.84 for IEV isolates), whereas a weaker IC50 value correlation between methods was noted...strains with varying drug susceptibility profiles: W2 and K1 (susceptible to mefloquine , and resistant to chloroquine), D6 (susceptible to chloroquine, and...resistant to mefloquine ), and 3D7 (susceptible to chloroquine, but less susceptible to mefloquine than W2). From the IC50 profiles of all parasite

  11. Power market competition

    International Nuclear Information System (INIS)

    Kelly, J.

    1998-01-01

    In the Unites States the prospect of greater competition in wholesale power market was immediately eclipsed by talk of retail competition. Attempts to move to retail competition have been costly and complex. Prudent public policy and economic analyses suggest that retail competition not be implemented until it can first be demonstrated that effective competition exists in wholesale power markets [it

  12. Lunabotics Mining Competition

    Science.gov (United States)

    Mueller, Rob; Murphy, Gloria

    2010-01-01

    This slide presentation describes a competition to design a lunar robot (lunabot) that can be controlled either remotely or autonomously, isolated from the operator, and is designed to mine a lunar aggregate simulant. The competition is part of a systems engineering curriculum. The 2010 competition winners in five areas of the competition were acknowledged, and the 2011 competition was announced.

  13. Competitive spirit

    Science.gov (United States)

    2000-01-01

    Leicester University will host the 65 international teams of students who will assemble in July for this year's International Physics Olympiad . The last time the Olympiad came to the UK was in 1986 in London, and it was the notable enthusiasm of the Leicester Physics and Astronomy department which persuaded the Olympiad Committee to give them the chance of organizing the prestigious event. The students taking part from all over the world are studying physics at A-level or an equivalent standard and they will take part in an intellectual marathon of theoretical and practical examinations. Each national team comprises five students selected from three rounds of competition and the teams will receive an official welcome from the city, as well as opportunities to visit some of the important educational and cultural centres of the surrounding region. The finalists will also be able to test their skills and initiative at the Challenger Learning Centre, which forms part of Leicester's new National Space Science Centre. Specific information on the event can be found on the Olympiad-2000 website at www.star.le.ac.uk/IphO-2000 . The Rudolf Ortvay problem solving contest in physics, which takes place in November, is a tradition of Eötvös University in Budapest, Hungary. The competition was first opened to international participants in 1998, enabling students from universities around the world to show their knowledge, ingenuity, problem-solving skills and physical insight into problems that are far beyond routine level. The problems (30 - 35 each year) are chosen from different branches of theoretical as well as applied physics. They have varying levels of difficulty, and every contestant can send solutions for ten problems. The focus is not on school-level problem-solving routines but rather on the `physical' way of thinking, recognition of the heart of the problem and an appropriate choice of mathematics. The majority of the assigned problems are original, few having

  14. IDRC Pre-ICN Forum on Competition and Development Alliance ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    dzavalamora

    2011-05-17

    May 17, 2011 ... Distinction Between Competition. Law and Competition Policy. • Traditional antitrust law: – Cartels. – Mergers. – Abuse of dominance. – (Possibly deceptive and misleading advertising). • Comprehensive competition policy - all laws and government actions that directly or indirectly restrict competition. 4 ...

  15. Privatization, Competition and Beyond

    Directory of Open Access Journals (Sweden)

    Mete Gundogan

    2010-08-01

    Full Text Available Privatization not only results in the transfer of state assets, but it also reduces economic role of the government. Developing and developed countries have experienced privatization in different ways for years. This article focuses upon the issue of privatization in Turkey. Turkey launched its comprehensive economic liberalization program named ‘structural adjustment reform' in 1980 by the stimulation of the World Bank and IMF. Later on, privatization has been an official state ideology with two institutions, the Privatization Higher Council and the Privatization Administration. Some of their implementations have been given. Privatization policies have multiple, often together with often inter-related and conflicting political, economic and financial objectives. They must be evaluated according to political, social and economical structures and conditions of the country concerned. Together with privatization, competition and its institutional framework with implementations have also been analyzed in the paper. The paper maintains that there seemed no direct and strong relationship between the privatization endeavours and institutional competition. Finally, the study points out that Turkey seems to be a bare-foot runner in its privatization venture unless there is a proper competitive market, together with a sound social security system and a profound capital market.

  16. The Necessity of ASEAN Competition Law: Rethinking

    Directory of Open Access Journals (Sweden)

    Udin Silalahi

    2017-12-01

    Full Text Available As outlined in the AEC Blueprint, all ASEAN member states (AMSs will endeavour to introduce competition policy by 2015. At present 7 (seven AMSs, namely: Indonesia, Singapore, Malaysia, Thailand, Vietnam, Philippines, Myanmar have the national competition laws to supervise anti-competitive conduct in the domestic market. But the question is what if happened unfair competition between ASEAN member states, due to the agreement or businesses activities by business actors that harm competition? ASEAN has an ASEAN Regional Guidelines on Competition Policy (ARGCP that developed by ASEAN Experts Group on Competition (AEGC as framework for member states to develop its own competition law or policy and as a guideline in measuring that directly affect the behaviour of enterprises and the structure of industry and markets. Regional Guideline is just to help AMSs in increasing of awareness of important policy, not to sustain the competition among ASEAN member countries. Until now there is no ASEAN Competition Law and Institution to oversee competition among ASEAN member countries. In this era, ASEAN economic integration it is a certainty that anti-competitive among AMSs will happen.

  17. Development of a highly sensitive and specific monoclonal antibody based enzyme-linked immunosorbent assay for the detection of a new β-agonist, phenylethanolamine A, in food samples.

    Science.gov (United States)

    Jiang, Danni; Cao, Biyun; Wang, Meiyu; Yang, Hong; Zhao, Kang; Li, Jianguo; Li, Mingxin; Sun, Lulu; Deng, Anping

    2017-02-01

    All β-agonists are banned as feed additives for growth promotion in animals due to toxic effects on humans after consuming the β-agonist contaminated meats. Phenylethanolamine A (PA) is a newly emerged β-agonist. Thus there is a need to develop highly sensitive and specific analytical methods for the detection of PA in food samples. In this study, the monoclonal antibody (mAb) against PA was produced by hybridoma technology and used for the development of enzyme-linked immunosorbent assay (ELISA). The IC 50 values and limits of detection (LODs) of the ELISA using homogeneous combination of coating antigen/antibody for PA were 0.16 ng mL -1 and 0.011 ng mL -1 , respectively. The cross-reactive (CR) values of the assay with 14 structurally related β-agonists were lower than 0.59%. Swine liver and meat samples were spiked with PA at different content and analysed by ELISA. Acceptable recovery rates of 91.40-105.51% and intra-assay coefficients of variation of 1.56-9.92% (n = 3) were obtained. The ELISA for seven spiked samples was confirmed by LC-MS/MS with a high correlation coefficient of 0.9881. The proposed mAb-based ELISA was highly sensitive and specific for PA and could be used as a quantitative/screening method for PA analysis in food samples. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Natural anti-insulin autoantibodies in cats: enzyme-linked immunosorbent assay for the determination of plasma anti-insulin IgG and its concentrations in domestic cats.

    Science.gov (United States)

    Takashima, Satoshi; Nishii, Naohito; Hachisu, Tatsuyuki; Kojima, Masaaki; Kigure-Hoshino, Megumi; Ogawa, Shizuko; Suzuki, Takafumi; Iwasawa, Atsushi; Ohba, Yasunori; Kitagawa, Hitoshi

    2013-12-01

    Anti-insulin immunoglobulin G (IgG) has been found in the sera of healthy cats. To determine the concentrations of these antibodies, an enzyme-linked immunosorbent assay (ELISA) for anti-insulin IgG was developed. ELISA maintained the linearity of a standard concentration line between 67.5 and 2160 ng/ml. The coefficients of variances (CVs) of intra-assays in two different plasma samples were 4.0% and 3.7%, respectively. The inter-assay CVs in two different plasma samples were 5.1% and 6.9%, respectively. The dilution curves of two samples were rectilinear. Anti-insulin IgG was detected in all 84 of the healthy cats that were tested. Plasma anti-insulin IgG concentrations ranged from 80 to 1578 μg/ml, with a median concentration of 221 μg/ml, and this value correlated positively with total plasma IgG concentrations (r=0.383, pglucose tolerance test, plasma anti-insulin IgG concentrations did not alter, even with changes in plasma glucose and insulin concentrations. The ELISA that was developed was able to determine plasma anti-insulin IgG in domestic cats, and confirmed that all healthy cats had plasma anti-insulin IgG. Determining the plasma concentrations of anti-insulin IgG in cats with various pathological conditions might clarify the role of anti-insulin IgG. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Comparison of sorbitol MacConkey agar and a two-step method which utilizes enzyme-linked immunosorbent assay toxin testing and a chromogenic agar to detect and isolate enterohemorrhagic Escherichia coli.

    Science.gov (United States)

    Novicki, T J; Daly, J A; Mottice, S L; Carroll, K C

    2000-02-01

    Enterohemorrhagic Escherichia coli (EHEC) and specifically serotype O157:H7 are a significant cause of hemorrhagic gastrointestinal disease and the hemolytic uremic syndrome. Methods currently used in clinical microbiology labs, such as sorbitol-MacConkey (SMAC) agar, reliably detect only O157:H7. We have evaluated a two-step method that has the potential to identify and isolate all EHEC serotypes, including serotype O157:H7. This method utilizes a chromogenic selective-differential medium for the isolation of E. coli together with an enzyme-linked immunosorbent assay (ELISA) that detects the Shiga-like toxins Stx1 and Stx2. Both are commercially available and usable in a wide range of clinical microbiology laboratories. Compared to a Vero cell cytotoxic assay, SMAC had sensitivities of 23.5% for the identification of all EHEC serotypes and of 50.0% for the identification of O157:H7 alone. The two-step method had sensitivities of 76.5 and 100%, respectively. The ELISA alone had a sensitivity of 82.4% in the detection of Stx1 and Stx2. The specificity was 100% in all cases. Overall, 14 EHEC isolates were obtained: 8 (58%) O157:H7, 2 (14%) O26, 2 (14%) O111:NM, 1 (7%) O103:H2, and 1 (7%) O121:H19. All but one were isolated during the months of May to September. The two-step method was found to be considerably more expensive than SMAC for both positive and negative samples.

  20. A comparison of titers of anti-Brucella antibodies of naturally infected and healthy vaccinated cattle by standard tube agglutination test, microtiter plate agglutination test, indirect hemagglutination assay, and indirect enzyme-linked immunosorbent assay

    Directory of Open Access Journals (Sweden)

    Anju Mohan

    2016-07-01

    Full Text Available Aim: We determined the antibody response in cattle naturally infected with brucellosis and normal healthy adult cattle vaccinated during calf hood with strain 19. Materials and Methods: The antibody titers were measured by standard tube agglutination test (STAT, microtiter plate agglutination test (MAT, indirect hemagglutination assay (IHA, and indirect enzyme-linked immunosorbent assay (iELISA as per standard protocols. Results: The mean STAT titers were 1.963±0.345 in infected cattle and 1.200±0.155 in healthy vaccinated cattle. The difference was extremely significant (p<0.0001. The mean MAT titers were 2.244±0.727 in infected cattle and 1.200±0.155 in healthy vaccinated cattle. The difference was very significant (p<0.005. The mean IHA titers in infected cattle were 2.284±0.574, and those in healthy vaccinated cattle were 1.200±0.155. The difference was extremely significant (p=0.0002. However, the difference in mean iELISA titers of infected cattle (1.3678±0.014 and healthy vaccinated cattle (1.367±0.014 was non-significant. The infected animals showed very high titers of agglutinating antibodies compared to the vaccinated animals. However, it cannot be ascertained whether these antibodies are due to vaccine or response to infection. Since the infected animals had been vaccinated earlier, the current infection may suggest that vaccination was unable to induce protective levels of antibody. The heightened antibody response after infection may also indicate a secondary immune response to the antigens common to the vaccine strain and wild Brucella organisms. Conclusion: The brucellosis infected animals showed very high titers of agglutinating antibodies compared to the vaccinated animals.

  1. Evaluation of an Erns-based enzyme-linked immunosorbent assay to distinguish Classical swine fever virus-infected pigs from pigs vaccinated with CP7_E2alf.

    Science.gov (United States)

    Pannhorst, Katrin; Fröhlich, Andreas; Staubach, Christoph; Meyer, Denise; Blome, Sandra; Becher, Paul

    2015-07-01

    Infections with Classical swine fever virus (CSFV) are a major economic threat to pig production. To combat CSF outbreaks and to maintain trade, new marker vaccines were developed that allow differentiation of infected from vaccinated animals (DIVA principle). The chimeric pestivirus CP7_E2alf was shown to be safe and efficacious. Its DIVA strategy is based on the detection of CSFV E(rns)-specific antibodies that are only developed on infection. However, for the new marker vaccine to be considered a valuable control tool, a validated discriminatory assay is needed. One promising candidate is the already commercially available enzyme-linked immunosorbent assay, PrioCHECK CSFV E(rns) ELISA (Prionics BV, Lelystad, The Netherlands). Four laboratories of different European Union member states tested 530 serum samples and country-specific field sera from domestic pigs and wild boar. The ELISA displayed a good robustness. However, based on its reproducibility and repeatability, ranges rather than single values for diagnostic sensitivity and specificity were defined. The ELISA displayed a sensitivity of 90-98% with sera from CSFV-infected domestic pigs. A specificity of 89-96% was calculated with sera from domestic pigs vaccinated once with CP7_E2alf. The ELISA detected CSFV infections in vaccinated domestic pigs with a sensitivity of 82-94%. The sensitivity was lower with sera taken ≤21 days post-challenge indicating that the stage of CSFV infection had a considerable influence on testing. Taken together, the PrioCHECK CSFV E(rns) ELISA can be used for detection of CSFV infections in CP7_E2alf-vaccinated and nonvaccinated domestic pig populations, but should only be applied on a herd basis by testing a defined number of animals. © 2015 The Author(s).

  2. DISSONANCE AND CONSONANCE BETWEEN THE COMPETITIVENESS OF

    Directory of Open Access Journals (Sweden)

    OANA CRISTINA POPOVICI

    2015-08-01

    Full Text Available The aim of this paper is to identify to what extent the notions of organizational and regional competitiveness are similar, in order to be targeted by a comprehensive set of public policy measures. In this respect, we discuss the notions of organizations’ and regional competitiveness and find common factors of influence, namely innovation, networks and regulation. Based on these factors, we search for empirical evidences as regards the mutual impact between the competitiveness of organizations and competitiveness of regions. We present the results using the example of foreign direct investment companies, as their location decision making process is based on assessing both the competitiveness of organizations and the advantages of locations that point to the competitiveness of a location and, extended, to that of a region. While the dissonance is expressed in the differences of interpretation for the two notions, there is a consonant policy that can be employed for supporting both organizational and regional competitiveness: the cluster policy.

  3. Chemical defense lowers plant competitiveness.

    Science.gov (United States)

    Ballhorn, Daniel J; Godschalx, Adrienne L; Smart, Savannah M; Kautz, Stefanie; Schädler, Martin

    2014-11-01

    Both plant competition and plant defense affect biodiversity and food web dynamics and are central themes in ecology research. The evolutionary pressures determining plant allocation toward defense or competition are not well understood. According to the growth-differentiation balance hypothesis (GDB), the relative importance of herbivory and competition have led to the evolution of plant allocation patterns, with herbivore pressure leading to increased differentiated tissues (defensive traits), and competition pressure leading to resource investment towards cellular division and elongation (growth-related traits). Here, we tested the GDB hypothesis by assessing the competitive response of lima bean (Phaseolus lunatus) plants with quantitatively different levels of cyanogenesis-a constitutive direct, nitrogen-based defense against herbivores. We used high (HC) and low cyanogenic (LC) genotypes in different competition treatments (intra-genotypic, inter-genotypic, interspecific), and in the presence or absence of insect herbivores (Mexican bean beetle, Epilachna varivestis) to quantify vegetative and generative plant parameters (above and belowground biomass as well as seed production). Highly defended HC-plants had significantly lower aboveground biomass and seed production than LC-plants when grown in the absence of herbivores implying significant intrinsic costs of plant cyanogenesis. However, the reduced performance of HC- compared to LC-plants was mitigated in the presence of herbivores. The two plant genotypes exhibited fundamentally different responses to various stresses (competition, herbivory). Our study supports the GDB hypothesis by demonstrating that competition and herbivory affect different plant genotypes differentially and contributes to understanding the causes of variation in defense within a single plant species.

  4. All competition is not alike: Neural mechanisms for resolving underdetermined and prepotent competition

    Science.gov (United States)

    Snyder, Hannah R.; Banich, Marie T.; Munakata, Yuko

    2014-01-01

    People must constantly select among potential thoughts and actions in the face of competition from (a) multiple task-relevant options (underdetermined competition) and (b) strongly dominant options that are not appropriate in the current context (prepotent competition). These types of competition are ubiquitous during language production. In this work, we investigate the neural mechanisms that allow individuals to effectively manage these cognitive control demands and to quickly choose words with few errors. Using fMRI, we directly contrast underdetermined and prepotent competition within the same task (verb generation) for the first time, allowing localization of the neural substrates supporting the resolution of these two types of competition. Using a neural network model, we investigate the possible mechanisms by which these brain regions support selection. Together, our findings demonstrate that all competition is not alike: resolving prepotent competition and resolving underdetermined competition rely on partly dissociable neural substrates and mechanisms. Specifically, activation of left ventrolateral prefrontal cortex is specific to resolving underdetermined competition between multiple appropriate responses, most likely via competitive lateral inhibition. In contrast, activation of left dorsolateral prefrontal cortex is sensitive to both underdetermined competition and prepotent competition from response options that are inappropriate in the current context. This region likely provides top-down support for task-relevant responses, which enables them to out-compete prepotent responses in the selection process that occurs in left ventrolateral prefrontal cortex. PMID:24742155

  5. COMPETITION ADVOCACY: CHALLENGE FOR COMPETITION POLICY

    Directory of Open Access Journals (Sweden)

    Anatolie CARAGANCIU

    2014-11-01

    Full Text Available A large variety of different countries conditions requires a modernization of criteria, norms and standards of competition regulation and methods of enforcement. Competition advocacy is a type of complementary activity exercised by antimonopoly authorities additional to enforcement measures, through active cooperation with market, government and civil society actors and increasing the understanding of the benefits of competition. Relevance of article is determined by summarizing the theoretical studies and the present practice of advocacy in the USA and the EU. Originality and practical applications of research are based on empirical studies completed by Moldovan Competition Board.

  6. Diversity begets diversity in competition for space

    Science.gov (United States)

    Daniel S. Maynard; Mark A. Bradford; Daniel L. Lindner; Linda T. A. van Diepen; Serita D. Frey; Jessie A. Glaeser; Thomas W. Crowther

    2017-01-01

    Competition can profoundly affect biodiversity patterns by determining whether similar species are likely to coexist. When species compete directly for space, competitive ability differences should theoretically promote trait and phylogenetic clustering, provided that niche differences are otherwise minimal. Yet many sessile communities exhibit high biodiversity...

  7. Evaluation of the Double Agar Gel Immunodiffusion Test and of the Enzyme-Linked Immunosorbent Assay in the Diagnosis and Follow-Up of Patients with Chronic Pulmonary Aspergillosis.

    Directory of Open Access Journals (Sweden)

    Priscila Zacarias de Azevedo

    Full Text Available The diagnosis of chronic pulmonary aspergillosis (CPA depends on the radiologic image and the identification of specific antibodies. The present study aimed to evaluate accuracy parameters of enzyme-linked immunosorbent assay (ELISA and of the determination of serum galactomannan level in the diagnosis of patients with CPA, comparing these results with the double agar gel immunodiffusion (DID test. In addition, the prevalence of cross-reactivity and the serological progression after treatment were evaluated by comparing DID and ELISA. Six study groups were formed: G1: 22 patients with CPA, 17 of whom had Aspergillus fungus ball, one chronic cavitary pulmonary aspergillosis (CCPA and four chronic fibrosing pulmonary aspergillosis (CFPA; G2: 28 patients with pulmonary tuberculosis (TB; G3: 23 patients with histoplasmosis (HST; G4: 50 patients with paracoccidioidomycosis (PCM; G5: 20 patients with cryptococcosis (CRC; and G6: 200 healthy controls. Serum antibodies were measured by DID and ELISA, with two antigen preparations--Aspergillus fumigatus (DID1, ELISA1 and a pool of A. fumigatus, A. flavus and A. niger antigens (DID2, ELISA2. The Platélia Aspergillus Enzyme Immunoassay (EIA kit was used to measure galactomannan. The cut-off points of ELISA were determined for each antigen preparation and for the 95% and 99% confidence intervals. Despite the low sensitivity, DID was the technique of choice due to its specificity, positive and negative predictive values and positive likelihood ratio-especially with the antigen pool and due to the low frequency of cross-reactivity. ELISA1 and a 0.090 cut-off showed high sensitivity, specificity and negative predictive value, but a high frequency of cross-reactivity with CRC. The best degree of agreement was observed between ELISA1 and ELISA2. The detection of serum galactomannan showed high sensitivity, comparable to ELISA2. The immunodiffusion test showed an excellent relationship with the progression after

  8. Validation and evaluation of VapA-specific IgG and IgG subclass enzyme-linked immunosorbent assays (ELISAs) to identify foals with Rhodococcus equi pneumonia.

    Science.gov (United States)

    Sanz, M G; Oliveira, A F; Loynachan, A; Page, A; Svansson, V; Giguère, S; Horohov, D W

    2016-01-01

    Rhodococcus equi (Rhodococcus hoagii/Prescottella equi) is a common cause of foal pneumonia, but its diagnosis remains a challenge for equine veterinarians. While the VapA-specific (virulence-associated protein A) immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) has low sensitivity and specificity for detecting pneumonic foals, little is known about VapA-specific IgG subclasses. To evaluate the performance of VapA-specific ELISA for IgG and its subclasses IgGa, IgGb and IgG(T) in the early diagnosis of pneumonia caused by R. equi. Assay validation followed by assessment of diagnostic performance using archived samples from animals of known status. Serum samples from exposed (n = 125) and nonexposed adult horses (n = 10) and from experimentally challenged and naturally infected foals were used for ELISA validation. Post mortem and tissue culture records of the last 24 years from the Institute for Experimental Pathology at the University of Iceland in Keldur, Iceland laboratory were evaluated to confirm the absence of R. equi cases in Iceland. The diagnostic performance of VapA-specific IgG and its subclasses was evaluated using banked serum samples from pneumonic (n = 21) and healthy foals (n = 80). To evaluate each IgG assay, a cut-off value was selected based on receiver operating characteristic curve analysis and used to calculate sensitivity and specificity. The intra- and interassay coefficients of variation were calculated for each ELISA. Using sera from Iceland, where R. equi infection has not been reported, the VapA-specific IgG ELISA differentiated exposed from nonexposed horses. When used to identify infected foals, VapA-specific IgG, IgGa and IgGb had no diagnostic value. In contrast, IgG(T) had high sensitivity and specificity. Horses from Iceland are not exposed to VapA(+) R. equi and can serve as negative controls. VapA-specific IgG subclasses, with the exception of IgG(T), are poor predictors of disease. Further

  9. Development and application of an enzyme-linked immunosorbent assay for specific detection of mangiferin content in various cultivars of Mangifera indica leaves using anti-mangiferin polyclonal antibody.

    Science.gov (United States)

    Yusakul, Gorawit; Kitirattrakarn, Wongsathorn; Tanwanichkul, Narunat; Tanaka, Hiroyuki; Putalun, Waraporn

    2012-04-01

    An enzyme-linked immunosorbent assay (ELISA) was developed for determining mangiferin content in plant samples using a polyclonal antibody (PAb) against mangiferin. The developed ELISA showed a full measurement range from 0.12 to 31.25 μg/mL mangiferin with a relative standard deviation (RSD) less than 6% for both intra- and interassay precision levels. The accuracy was determined by a percent recovery experiment at three concentration levels and it showed 97.8%-103.7% recovery in Mangifera indica leaf samples. The developed ELISA exhibited a high correlation value (R² = 0.992) with the standard high-performance liquid chromatography (HPLC) method in various mangiferin-containing plant samples. Our results suggest that the validated ELISA methodology using a PAb against mangiferin can be applied to determine mangiferin content with high specificity, rapidity and simplicity in various mangiferin-containing plant samples. The mangiferin content in the mature leaves of fifty M. indica cultivars were determined using the developed ELISA. The mangiferin contents ranged from 1.94 ± 0.13% to 13.79 ± 0.84% dry wt. The Thawai cultivar leaves contained the highest level of mangiferin (13.79 ± 0.84% dry wt), but it is a rare cultivar. The Namdokmai, which is more commonly cultivated in Thailand, contain 12.41 ± 0.60% dry wt mangiferin; therefore, this cultivar leaf was recommended as the source of raw material for the pharmaceutical, nutraceutical and cosmetic product industries. Currently, natural heath products are accepted worldwide for healthcare. Mangiferin-containing plants and products exhibit health benefits against oxidative stress-related diseases, such as cardiovascular diseases, cancer, dyslipidemia and diabetes. We have developed an ELISA with high specificity, rapidity and simplicity for the quality control of mangiferin-derived product production. Moreover, we found that the Namdokmai leaf, a Thai M. indica cultivar, was recommended as the source of raw

  10. Serum concentration of 20K human growth hormone (20K hGH) measured by a specific enzyme-linked immunosorbent assay. Study Group of 20K hGH.

    Science.gov (United States)

    Tsushima, T; Katoh, Y; Miyachi, Y; Chihara, K; Teramoto, A; Irie, M; Hashimoto, Y

    1999-01-01

    Several GH isoforms have been identified in pituitary and serum, the most abundant of which is the 22K human GH (hGH) isoform. The 20K hGH isoform is produced by alternative splicing of GH messenger ribonucleic acid and comprises approximately 10% of all GH in the pituitary. The physiological role of 20K hGH remains to be determined, partly because of the lack of a simple and specific assay. We have established sensitive enzyme-linked immunosorbent assays (ELISAs) specific to 20K and 22K hGH. To determine whether regulation of 20K hGH secretion is the same as that for 22K hGH, we measured serum concentrations of both species of hGH in normal subjects and patients with a variety of endocrine disorders. The serum levels of 20K hGH after overnight fasting was 118 +/- 178 pg/mL (n = 282) in normal women, significantly higher than that in normal men (64 +/- 170 pg/mL; n = 226). However, there was no difference in the proportion of 20K hGH to 20K plus 22K hGH between men (6.3 +/- 2.6%, mean +/- SD; n = 176) and women (6.3 +/- 2.1%; n = 263). No correlation was detected between the ratio of 20K hGH and age, body height, body weight, or body fat mass in normal subjects. The proportion of 20K hGH was significantly (P hGH in successfully treated acromegalic patients did not differ from that in normal subjects, suggesting that GH-producing pituitary tumors secrete a higher proportion of 20K hGH, or that a chronic excess of 22K hGH alters the MCR of 20K hGH. The values in patients with adult GH deficiency, hyperthyroidism, primary hypothyroidism, or GH-independent short stature did not differ from those in normal subjects. The 20K ratio did not change after acute GH provocative tests, such as the insulin tolerance test and the GHRH test. These results suggest that secretion of 20K hGH from the pituitary is under the same control as that of 22K hGH. This new assay may provide a tool for understanding the physiological or pathophysiological role of the 20K hGH isoform.

  11. Global Oligopolistic Competition and Foreign Direct Investment

    DEFF Research Database (Denmark)

    Hansen, Michael W.; Hoenen, Anne K.

    2016-01-01

    Purpose: The purpose of this paper is to re-visit and re-invigorate the oligopolistic industry perspective on multinational corporations (MNC) strategy. Design/methodology/approach: Based on insights from the industrial organization tradition and strategic management, the paper brings the original...... capabilities across borders. The paper argues that progressing global concentration in many industries warrants a rediscovery of the oligopolistic perspective on FDI. Originality/value: The paper provides a comprehensive and unique literature review of the literature on MNC strategy in oligopolistic industries...

  12. Competitive natural gas market situation and prospects

    International Nuclear Information System (INIS)

    Cazzola, C.; Grillo, M.

    1998-01-01

    This article evaluates the prospects for achieving a competitive market in the natural gas industry, according to the common rules for the internal market established by the Directive 98/30/CE of 22 June 1998. Firstly, for the organisation of the access to the system, the regulated, rather than the negotiated, procedure would ensure a better opportunity to promote competition in the market. Secondly, the establishment of a competitive market calls for the effective separation of the phases of production characterized by natural monopoly from the phases which may be developed in a competitive setting [it

  13. Does competition influence safety?

    International Nuclear Information System (INIS)

    Pamme, H.

    2000-01-01

    Competition in the deregulated electricity market does not leave nuclear power plants unaffected. Operators seek to run their plants at maximum availability and with optimized cost structures so that specific generating costs are minimized. The 'costs of safety', with their fixed-cost character, are elements of this cost structure. Hence the question whether safety is going to suffer under the cost pressure on the market. The study shows that the process of economic optimization does not permit cost minimization for its own sake in the area of operating costs which can be influenced by management or are 'avoidable'. The basis of assessment rather must be potential risks which could entail losses of availability. Prophylactic investments made in order to avoid losses of availability to a large extent also imply unchanged or even higher levels of safety. Economic viability and safety thus are closely correlated. Competition in a deregulated marekt so far has not done any direct harm to plant safety. An even more efficient use of scarce funds and, hopefully, a tolerable political environment should allow the safety level of nuclear power plants to be upheld, and safety culture to be maintained, also in the future. (orig.) [de

  14. SAFETY ASPECTS OF SPORTS COMPETITION

    Directory of Open Access Journals (Sweden)

    Srećko Novaković

    2011-09-01

    Full Text Available Sport, as an activity of public interest in contemporary conditions of life,has an important role in almost every state. Financial and security of participation of the state in the sports field, through the budgets of all levels are important issues regardless of the status and relationships of government and non-governmental organizations and sports associations. Cooperation and clear definition of security responsibilities between public authorities and sports clubs is essential and widely accepted phenomenon. The causes of conflict in sport competitions are polyvalent. It affects the study of this type of security phenomena that must be approached from different aspects. The causes of conflict in sports competitions may be direct and indirect, structural, economic - social, political and cultural - perceptual. All together they contribute to the occurrence of conflict and measuring the occurrence and development of modern security phenomenon in sport competitions

  15. Competition on European energy markets

    International Nuclear Information System (INIS)

    Lijesen, M.; Speck, S; Mulder, M.

    2003-01-01

    The launch of the Directives on Electricity and Gas in the late 1990s was the starting point for creating common and competitive energy markets in the European Union. The main goal of this process was to increase efficiency of allocation of resources and, hence,enhance consumer welfare. More specifically, increasing competition within the energy markets should lead to a reduction of energy prices and to a convergence of prices among EU member states. Within a year from now, end-users in the Netherlands will be free to choose their own supplier, thus finalising the deregulation of Dutch energy markets. What lessons may be learned from the experience thus far? What are the results of the liberalisation process up to now? How have prices developed,and can these developments be explained? How afraid should we be for the lights to go out in a competitive electricity market?

  16. 48 CFR 19.808-2 - Competitive.

    Science.gov (United States)

    2010-10-01

    ... PROGRAMS SMALL BUSINESS PROGRAMS Contracting With the Small Business Administration (the 8(a) Program) 19... conducts negotiations directly with the competing 8(a) firms. Conducting competitive negotiations among 8(a...

  17. Performance during competition and competition outcome in relation to testosterone and cortisol among women.

    Science.gov (United States)

    Henry, Andrea; Sattizahn, Jason R; Norman, Greg J; Beilock, Sian L; Maestripieri, Dario

    2017-06-01

    A contribution to a special issue on Hormones and Human Competition. This study investigated the relation between competition, testosterone (T), and cortisol (C) in women. One hundred and twenty female participants competed against a male confederate in a computerized laboratory task. The task was preprogrammed so that half the women won and half of the women lost the competition. T and C concentrations were measured in saliva samples collected at four time points before and after the competition. Accuracy and reaction time during the competition were recorded. T and C increased directly after the competition, though not significantly for C, and then decreased over time regardless of the competition outcome. Regression analyses demonstrated that baseline T was significantly and positively associated with competition accuracy, though only in individuals who were low in C. Individuals who were high in C showed no relation between T and accuracy. This relation was further qualified by competition outcome. Losers of the competition showed a significant positive relation between baseline T levels and competition accuracy, though only if they were low in C. No relation was found between T and accuracy in losers who were high in C. Winners of the competition showed no relation between T and accuracy, regardless of whether C levels were high or low. These results are in line with the dual-hormone hypothesis, whereby the effects of T on status-seeking behaviors are dependent on C levels for individuals whose status is threatened. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Diversifying evolution of competitiveness.

    Science.gov (United States)

    Baldauf, Sebastian A; Engqvist, Leif; Weissing, Franz J

    2014-10-29

    In many species, individuals express phenotypic characteristics that enhance their competitiveness, that is, the ability to acquire resources in competition with others. Moreover, the degree of competitiveness varies considerably across individuals and in time. By means of an evolutionary model, we provide an explanation for this finding. We make the assumption that investment into competitiveness enhances the probability to acquire a high-quality resource, but at the same time reduces the ability of exploiting acquired resources with maximal efficiency. The model reveals that under a broad range of conditions competitiveness either converges to a polymorphic state, where individuals differing in competitive ability stably coexist, or is subject to perpetual transitions between periods of high and low competitiveness. The dynamics becomes even more complex if females can evolve preferences for (or against) competitive males. In extreme cases, such preferences can even drive the population to extinction.

  19. Lunar Regolith Excavation Competition

    Science.gov (United States)

    Liles, Cassandra

    2009-01-01

    The Lunar Regolith Excavation Competition is a new competition that needs graphics, logos, rules, as well as an arena. Although this is the first year of the competition, the competition is modeled after an existing competition, the Centennial Lunar Excavator Challenge. This competition however is aimed at college students. This makes the challenge identifying key aspects of the original competition and modeling them to fit into an easier task, and creating exciting advertisement that helps encourage participation. By using a youth focus group, young insight, as well as guiding advice from experts in the field, hopefully an arena can be designed and built, rules can be molded and created to fit, and alluring graphics can be printed to bring about a successful first year of the Lunar Regolith Excavation Competition.

  20. Diversifying evolution of competitiveness

    NARCIS (Netherlands)

    Baldauf, Sebastian A.; Engqvist, Leif; Weissing, Franz J.

    2014-01-01

    In many species, individuals express phenotypic characteristics that enhance their competitiveness, that is, the ability to acquire resources in competition with others. Moreover, the degree of competitiveness varies considerably across individuals and in time. By means of an evolutionary model, we

  1. Competition in EU banking

    NARCIS (Netherlands)

    De Jonghe, Olivier; Diepstraten, Maaike; Schepens, Glenn; Beck, Thorsten; Casu, Barbara

    2017-01-01

    This chapter discusses recent EU-wide movements in bank competition and concentration. We start with a concise overview of the most frequently used competition and concentration measures. Given that different measures may capture different aspects of bank competition, we focus on the differences and

  2. Productive and Unproductive Competition

    DEFF Research Database (Denmark)

    Guerra, Alice; Luppi, Barbara; Parisi, Francesco

    Conventional theories of competition classify contests as being either “productive,” when the competitive efforts generate a surplus for society, or “unproductive,” when competition generates no social surplus and merely distributes already existing resources. These two discrete categories of com...

  3. Competition and Innovation Policy

    OpenAIRE

    Philip Lowe

    2008-01-01

    Innovation and competition go hand in hand. Innovative markets are competitive markets and innovative companies succeed in them. In the European Commission, as in competition authorities across the world, our focus is on ensuring that this happens in the most efficient and fair manner.

  4. Competition for Assistance Agreements

    Science.gov (United States)

    It is EPA policy to promote competition in the award of assistance agreements to the maximum extent practicable.When assistance agreements are awarded competitively, it is EPA policy that the competitive process be fair and open & that no applicant receive

  5. Increasing the competitiveness of banks

    OpenAIRE

    Badaeva V.; Makukhina Y.

    2017-01-01

    The article examines about the essence of competitiveness of banks, the ways of improving it, competitive advantages and factors which influence the effectiveness and competitiveness of banking institutions.

  6. COMPETITIVENESS THROUGH INFORMATION

    Directory of Open Access Journals (Sweden)

    Raluca Daniela RIZEA

    2013-10-01

    Full Text Available Intelligence competitiveness has already started to build its road in the company’s long term strategies. Nonetheless, business executives continue to look for ways to apply information technology strategically to their businesses. Using information managers manage to communicate, to convey their knowledge about markets, competitors, products, services and operations. Even if data and information are all over there are few amounts of managers that realize the importance of them to the success of the business. This article will review competitive forces and competitive information systems strategies for gaining competitive advantages, explain concepts of value chain, value co-opetition (competition and cooperation, and discuss innovation strategy. Co-opetition is a strategy whereby companies cooperate and compete at the same time with their competitors, complementors (i.e. hardware and software businesses, customers, suppliers. The article discuss an important dimension of information system, identifies competitive advantages and enhancing competitive strategies thought information systems.

  7. 43 CFR 13.5 - Protection from competition.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Protection from competition. 13.5 Section... BLIND PERSONS § 13.5 Protection from competition. (a) The head of the Interior bureau or office shall protect the blind operator of the vending facility against direct competition from other vendors or...

  8. Green competitiveness research on Chinese automotive enterprises

    Directory of Open Access Journals (Sweden)

    Yuanhui Li

    2014-05-01

    Full Text Available Purpose: More and more executives of automobileindustry in China start to recognize the concept of green competitiveness recently. However, relatively less research attention has been devoted to the consideration of measurement. This paper aims to find empirical approach to quantify green competitiveness for automotive enterprises. The connotation of green competitiveness is explored and one suite of evaluation index system has been proposed with four dimensions including environmental, resource, capability and knowledge.Design/methodology/approach: By introducing the factor analysis method, green competitiveness has been measured through an empirical analysis of 24 automotive enterprises within China.Findings: The results indicate that those elements, such as enterprise resource possession and utilization; environment, responsibility and knowledge; profitability; management efficiency, have significant effect on the green competitiveness for automotive enterprises. The further analysis also unveils the advantages and disadvantages of green competitiveness for each company and the direction for improvement.Research limitations/implications: Guide regulators and managers of automobile industry to take some measures to enhance their green competitive advantage.Practical implications: Provide practical methods to measure green competitiveness for automotive enterprises.Originality/value: This paper proposes an evaluation index system of green competitiveness for automotive enterprises. The suggestions of our research will be beneficial to enterprise executives and industry regulators.

  9. Logistics as factor to competitiveness enterprise rail-freight traffic

    OpenAIRE

    Yakimenko, N.; Ustenko, M.

    2009-01-01

    Considered need of the introduction on enterprise logistical technology for the reason increasing of competitiveness. Offered creation industrial-transport conglomerate in directions international transport corridor.

  10. Gender and Competition in Adolescence

    DEFF Research Database (Denmark)

    Dreber, Anna; Essen, Emma von; Ranehill, Eva

    2013-01-01

    We look at gender differences among adolescents in Sweden in preferences for competition, altruism and risk. For competitiveness, we explore two different tasks that differ in associated stereotypes. We find no gender difference in competitiveness when comparing performance under competition...

  11. Linking Urban Planning and Competitiveness of Tourist Destinations

    OpenAIRE

    Thays Cristina Domareski Ruiz; José Manoel Gândara

    2013-01-01

    The study of competitiveness has been driven from new contexts, such as the competitiveness of tourist destinations, which has caused significant changes in terms of knowledge production, mixing areas and providing a multidisciplinary reflection. This article aims to analyze the link between urban planning and competitiveness of tourist destinations, two concepts that directly reflect the development of cities. The methodology used was a literature review, analyzing models of competitiveness...

  12. Review of the BCI Competition IV

    Science.gov (United States)

    Tangermann, Michael; Müller, Klaus-Robert; Aertsen, Ad; Birbaumer, Niels; Braun, Christoph; Brunner, Clemens; Leeb, Robert; Mehring, Carsten; Miller, Kai J.; Müller-Putz, Gernot R.; Nolte, Guido; Pfurtscheller, Gert; Preissl, Hubert; Schalk, Gerwin; Schlögl, Alois; Vidaurre, Carmen; Waldert, Stephan; Blankertz, Benjamin

    2012-01-01

    The BCI competition IV stands in the tradition of prior BCI competitions that aim to provide high quality neuroscientific data for open access to the scientific community. As experienced already in prior competitions not only scientists from the narrow field of BCI compete, but scholars with a broad variety of backgrounds and nationalities. They include high specialists as well as students. The goals of all BCI competitions have always been to challenge with respect to novel paradigms and complex data. We report on the following challenges: (1) asynchronous data, (2) synthetic, (3) multi-class continuous data, (4) session-to-session transfer, (5) directionally modulated MEG, (6) finger movements recorded by ECoG. As after past competitions, our hope is that winning entries may enhance the analysis methods of future BCIs. PMID:22811657

  13. PRICES IN COMPETITIVE SYSTEM

    Directory of Open Access Journals (Sweden)

    VADUVA MARIA

    2017-08-01

    Full Text Available Regularities of competitive market determine rules for determining prices and their dynamics. Orientation prices to competition (competitive pricing is the strategy most frequently used in countries with market economies and especially for exports. Moreover, in an economy dominated by market competition it cannot be ignored without certain risks the prices resulting from competition between products bidders. Companies that use this type of strategy seek to maintain a level of prices linked to that charged by other competitors (or exporting producers generally no longer covering production costs or demand, relying on the assumption that the average market price is a reasonable basis of costs. But the way how practical guidance and reporting to the competition in every price strategy, will be determined by the company's market position, by the available power and enjoyed prestige, objectives and prospects of its market share etc. according to these elements, there may be several versions of pricing strategies oriented to competitors.

  14. Competition in electricity markets

    International Nuclear Information System (INIS)

    Taylor, W.

    1996-01-01

    This article examines expanded wholesale and retail competition and the effect that they are likely to have on the electric power industry. The author believes that expanded wholesale competition is good and will bring immediate benefit to all electric consumers; however, based on the experience of the natural gas industry and the electric power industry in California and other parts of the world, the author counsels caution in moving toward expanded retail competition

  15. Quality and Competition

    OpenAIRE

    Rajiv D. Banker; Inder Khosla; Kingshuk K. Sinha

    1998-01-01

    In recent years, the practitioner literature in operations management has seen a dramatic surge in articles on quality management. It reflects the increased emphasis on quality by U.S. firms, which has been attributed largely to increased competition faced by them. The question of how quality is influenced by competitive intensity, however, has not received much attention, either in the practitioner or the academic research literatures. The notion of competitive intensity itself has not been ...

  16. Retail Electricity Competition

    OpenAIRE

    Joskow, Paul L.; Tirole, Jean

    2004-01-01

    We analyze a number of unstudied aspects of retail electricity competition. We first explore the implications of load profiling of consumers whose traditional meters do not allow for measurement of their real time consumption, when consumers are homogeneous up to a scaling factor. In general, the combination of retail competition and load profiling does not yield the second best prices given the non price responsiveness of consumers. Specifically, the competitive equilibrium does not support ...

  17. Gender differences in competitiveness

    OpenAIRE

    Lackner, Mario

    2016-01-01

    Differences in labor market outcomes for women and men are highly persistent. Apart from discrimination, one frequently mentioned explanation could be differences in the attitude towards competition for both genders. Abundant empirical evidence indicates that multiple influences shape attitudes towards competition during different periods of the life cycle. Gender differences in competitiveness will not only influence outcomes during working age, but also during early childhood education. In ...

  18. Coal and the competition

    Energy Technology Data Exchange (ETDEWEB)

    Morey, M. [RDI Consulting, Arlington, VA (United States). FT Energy

    2000-07-01

    24 overheads/viewgraphs outline a presentation on competition in the US coal industry. It discussed four main subjects: key factors driving coal demand (environmental regulations, electric utility deregulation; competition with natural gas, inter-regional coal competition, supply availability and pricing; and the export market and competition from off-shore coal sources); coal's ability to boost market share; shifts in coal distribution and the risk of more branded coal; and attempts to keep more regional sources of coal in business. State tax incentives for coal use in Arizona, Ohio, Oklahoma, Virginia and Alabama were discussed.

  19. Can market forces and competition supplant regulation?

    International Nuclear Information System (INIS)

    Graham, D.

    1998-01-01

    The challenges facing regulators and governments as utilities and pipelines transform from regulated monopolies into competitive businesses were discussed. In the past, the absence of competition required that utility and pipeline companies be regulated by governments to ensure fair pricing and good performance. The question of whether or not competition can entirely replace regulation was examined. Although the focus was on the natural gas industry, the regulatory trends in other industries were also briefly considered. In 1985, the federal government agreed to allow the commodity price of natural gas to fluctuate in response to market forces. This began the process of deregulation in the Canadian natural gas industry. Direct purchasing introduced competition and ended the monopolies of local distribution companies in purchasing gas. The main benefits of the competitive market structure were that consumers could choose products and services from a range of competing companies at competitive prices. This was critical to the success of the Canadian economy since Canada is the third largest exporter of energy and the eighth largest consumer of energy. It was suggested that even in a competitive market abuse of market power is possible, therefore, there is an important role for government in ensuring the existence of a level playing field. A variety of issues involved in an effective transition to a competitive market were also discussed. 2 figs

  20. A phase transition for competition interfaces

    NARCIS (Netherlands)

    Ferrari, P.A.; Martin, J.B.; Pimentel, L.P.R.

    2009-01-01

    We study the competition interface between two growing clusters in a growth model associated to last-passage percolation. When the initial unoccupied set is approximately a cone, we show that this interface has an asymptotic direction with probability 1. The behavior of this direction depends on the

  1. African Competition Forum: Promoting Open and Competitive ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Markets in developing countries are often marked by anti-competitive behaviour, concentrated market power, and low access for newcomers. This limits local enterprise development and innovation. This project supports African countries in their bid to promote markets that work better for all producers and consumers.

  2. Determinação da infecção por Entamoeba histolytica em residentes da área metropolitana de Belém, Pará, Brasil, utilizando ensaio imunoenzimático (ELISA para detecção de antígenos Determination of Entamoeba histolytica infection in patients from Greater Metropolitan Belém, Pará, Brazil, by enzyme-linked immunosorbent assay (ELISA for antigen detection

    Directory of Open Access Journals (Sweden)

    Mônica Cristina de Moraes Silva

    2005-06-01

    Full Text Available O status epidemiológico da amebíase está sendo reavaliado desde que a Entamoeba histolytica (patogênica foi considerada espécie distinta de Entamoeba dispar (não patogênica. Em nosso estudo, realizamos pesquisa de antígenos de E. histolytica em amostras fecais de pacientes residentes na cidade de Belém, Pará, Brasil, utilizando ensaio imunoenzimático (E. histolytica Test, TechLab Inc., Blacksburg, Estados Unidos disponível comercialmente. Foram analisadas 845 amostras, com positividade em 248 (29,35%. A infecção por E. histolytica foi maior no grupo etário acima de 14 anos (30,36% que no grupo de 0-14 anos (28,28%, porém sem significância estatística (p The epidemiological status of amebiasis has been reevaluated since Entamoeba histolytica (pathogenic was considered a distinct species from Entamoeba dispar (non-pathogenic. We investigated E. histolytica antigens in stool samples from residents of Belém, Pará State, Brazil, with commercially available enzyme-linked immunosorbent assay (E. histolytica Test, TechLab Inc., Blacksburg, USA. A total of 845 samples were analyzed, of which 248 were positive (29.35%. E. histolytica infection was more frequent in the over-14-year age group (30.36% than in the 0-14-year group (28.28%, but the difference was not statistically significant (p < 0.05. Of all the samples, 334 were also submitted to parasitological methods (direct, Hoffman, and Faust et al.. There were discordant results between ELISA and parasitological methods in 83 samples (24.85%, with more positive results using ELISA. Our results thus suggest that intestinal amebiasis is an important public health problem in Greater Metropolitan Belém.

  3. BDS thin film damage competition

    Energy Technology Data Exchange (ETDEWEB)

    Stolz, C J; Thomas, M D; Griffin, A J

    2008-10-24

    A laser damage competition was held at the 2008 Boulder Damage Symposium in order to determine the current status of thin film laser resistance within the private, academic, and government sectors. This damage competition allows a direct comparison of the current state-of-the-art of high laser resistance coatings since they are all tested using the same damage test setup and the same protocol. A normal incidence high reflector multilayer coating was selected at a wavelength of 1064 nm. The substrates were provided by the submitters. A double blind test assured sample and submitter anonymity so only a summary of the results are presented here. In addition to the laser resistance results, details of deposition processes, coating materials, and layer count will also be shared.

  4. Competition research improves services

    International Development Research Centre (IDRC) Digital Library (Canada)

    5. Case study. THE POWER OF COMPETITIVE MARKETS. Competition and Development. One issue that all migrant workers face is how to send some of ... send some of their hard-earned wages home — quickly, safely, and at the lowest possible cost. Few have bank accounts. This might seem like a minor issue to people ...

  5. Competition: Was Kohn Right?

    Science.gov (United States)

    Shields, David Light; Bredemeier, Brenda Light

    2010-01-01

    Alfie Kohn made the case for competition being destructive to education. The truth may be that there are two separate ways to contest: true competition, which is a healthy desire to excel, and decompetition, which is the unhealthy desire merely to beat the opponent. Decompetition leads to the ills that Kohn enumerated. Educators should teach their…

  6. Competition, Ownership and Productivity

    DEFF Research Database (Denmark)

    Baghdasaryan, Delia; la Cour, Lisbeth

    2013-01-01

    Theoretical results support two concurrent views regarding the mediating role that ownership structure might play on the effect of competition on firm performance. According to one stream of literature, competition has a high, positive impact in companies that have an effective ownership structur...

  7. Multinationals and Institutional Competitiveness

    DEFF Research Database (Denmark)

    Hull Kristensen, Peer; Morgan, Glenn

    by forming firms capable of expanding internationally. At the level of subsidiaries as providing institutional back up for these firms' abilities to fight for survival and growth within the frame of rivalling subsidiaries of the MNC. The article discusses at these two levels the comparative institutional...... competitiveness of Liberal Market Economies and Coordinated Markets Economies under the current competitive regime....

  8. The competitive challenge

    International Nuclear Information System (INIS)

    Burr, M.T.

    1992-01-01

    This article examines the strategies necessary to succeed in the increasingly competitive independent power industry. The topics of the article include the factors encouraging mergers, acquisitions, and joint ventures, the availability of financing, changes in the market, regulatory climate changes, competition and power planning, Not In My Back Yard and project siting, and the road ahead

  9. Crop–weed competition

    DEFF Research Database (Denmark)

    Gallandt, Eric R.; Weiner, Jacob

    2015-01-01

    importantly, weed density and time of emergence relative to the crop. Practices that (1) reduce the density of weeds, (2) maximise occupation of space or uptake of resources by the crop or (3) establish an early-season size advantage of the crop over the weeds will minimise the competitive effects of weeds...... an early-season competitive advantage to the crop and (3) maximising resource capture by the crop using competitive species, competitive cultivars, high sowing densities, optimal spatial arrangement, intercropping complimentary species or transplanting.......Competition from weeds is the most important of all biological factors that reduce agricultural crop yield. This occurs primarily because weeds use resources that would otherwise be available to the crop. The magnitude of yield loss is affected by numerous agronomic and environmental factors, most...

  10. Competition in investment banking

    Directory of Open Access Journals (Sweden)

    Katrina Ellis

    2011-01-01

    Full Text Available We construct a comprehensive measure of overall investment banking competitiveness for follow-on offerings that aggregates the various dimensions of competition such as fees, pricing accuracy, analyst recommendations, distributional abilities, market making prowess, debt offering capabilities, and overall reputation. The measure allows us to incorporate trade-offs that investment banks may use in competing for new or established clients. We find that firms who switch to similar-quality underwriters enjoy more intense competition among investment banks which manifests in lower fees and more optimistic recommendations. Investment banks do compete vigorously for some clients, with the level of competition related to the likelihood of gaining or losing clients. Finally, investment banks not performing up to market norms are more likely to be dropped in the follow-on offering. In contrast, firms who seek a higher reputation underwriter face relatively non-competitive markets.

  11. Competitiveness through strategic orientation

    Directory of Open Access Journals (Sweden)

    Diego Monferrer

    2012-12-01

    Full Text Available The aim of this paper is to further the study of the factors that influence the international competitive position of international new ventures and, consequently, their international performance. Specifically, we analyze the role of entrepreneurial and market orientations in the international competitive position of such firms. Data were collected at Spanish and Belgian international new ventures. The structural equations model approach was used to test our hypotheses. Both the Spanish and the Belgian sample revealed a positive and significant relationship between entrepreneurial orientation and market orientation. Furthermore, both orientations have a positive and significant effect on the international competitive position of such firms. Finally, any firm’s international competitive position is positively and significantly related to its international performance. The study therefore appears to indicate that, when it comes to international new ventures, the conjunction of these two orientations is a key factor to attaining a superior competitive position and a positive performance in international markets.

  12. Heterogeneous logics of competition

    DEFF Research Database (Denmark)

    Mossin, Christiane

    2015-01-01

    The purpose of the article is to demonstrate that in order to understand competition as a socially organizing phenomenon, we should not examine competition in isolation, but as constellations of heterogeneous logics. More precisely, the article is based on two main theoretical points: (1) Logics...... of a presumed logic of competition within EU law, whereas the second part focuses on particular legal logics. In this respect, the so-called ‘real link criterion’ (determining the access to transnational social rights for certain groups of unemployed people) is given special attention. What is particularly...

  13. Gaining Relational Competitive Advantages

    DEFF Research Database (Denmark)

    Hu, Yimei; Zhang, Si; Li, Jizhen

    2015-01-01

    Establishing strategic technological partnerships (STPs) with foreign partners is an increasingly studied topic within the innovation management literature. Partnering firms can jointly create sources of relational competitive advantage. Chinese firms often lack research and development (R......&D) capabilities but are increasingly becoming preferred technological partners for transnational corporations. We investigate an STP between a Scandinavian and a Chinese firm and try to explore how to gain relational competitive advantage by focusing on its two essential stages: relational rent generation...... and appropriation. Based on an explorative case study, we develop a conceptual framework that consists of process, organizational alliance factors, and coordination modes that we propose lead to relational competitive advantage....

  14. Competitiveness: new economic paradigm?

    Directory of Open Access Journals (Sweden)

    Marlene Peñaloza

    2005-10-01

    Full Text Available Nowadays competitiveness is made up of “the new” paradigm that allows to prevail in the global World. Thus, it is inevitable to ask, was it required to be competitive to be successful in the international trade arena? Recognizing the discussion about it and its theoretical-conceptual density, the present paper studies this old notion whose meaning, in essence, is always the same one. This applies even though new realities in the present world-wide atmosphere confer to it a distinguishing character and new and old players are forced to organize actions and bring efforts together to obtain the competitive supremacy.

  15. Competition in education

    DEFF Research Database (Denmark)

    Knudsen, Hanne; Christensen, Søren

    Competition in education has two functions: selection and motivation. How do these two functions correlate, contradict or co-exist? How has the educational system reflected on the relation between competition as motivational technology and as a technology for selection? The aim of this paper...... is to formulate the problem of competition in education as a relation between selection and motivation and provide an analytical strategy to grasp this problem. Our ambition is to theorize the problem and give empirical illustrations of how the connection between selection and motivation has been articulated...... in various educational institutions and programs....

  16. Pollution taxes and international competitiveness

    International Nuclear Information System (INIS)

    Birch Soerensen, P.

    1994-01-01

    Throughout the industrialized world policy makers are becoming increasingly aware of the potential gains in economic efficiency and environmental quality to be reaped in certain areas of pollution control by switching from direct regulation to market-oriented policy instruments such as pollution taxes. However, concern about the impact on the international competitiveness of domestic producers seems to make governments in many countries hesitant to introduce pollution taxes. As a result, several observers have called for international agreements on harmonized pollution taxes among larger groups of countries such as the member states of the European Community. This paper argues that policy makers should be less concerned about the effects of pollution taxes on international competitiveness and more conscious about their effects on economic efficiency and equity. If pollution taxes improve the allocation of resources, it would be possible to compensate those citizens who might lose from their introduction and still leave the rest of society better off. The openness of the economy only means that a given improvement of environmental quality can be achieved through a lower level of pollution tax rates than would be necessary in a closed economy, because a given pollution tax rate will cause a greater contraction of output in polluting industries, the more these industries are exposed to foreign competition. (EG)

  17. Competitive Dynamics on Complex Networks

    Science.gov (United States)

    Zhao, Jiuhua; Liu, Qipeng; Wang, Xiaofan

    2014-07-01

    We consider a dynamical network model in which two competitors have fixed and different states, and each normal agent adjusts its state according to a distributed consensus protocol. The state of each normal agent converges to a steady value which is a convex combination of the competitors' states, and is independent of the initial states of agents. This implies that the competition result is fully determined by the network structure and positions of competitors in the network. We compute an Influence Matrix (IM) in which each element characterizing the influence of an agent on another agent in the network. We use the IM to predict the bias of each normal agent and thus predict which competitor will win. Furthermore, we compare the IM criterion with seven node centrality measures to predict the winner. We find that the competitor with higher Katz Centrality in an undirected network or higher PageRank in a directed network is most likely to be the winner. These findings may shed new light on the role of network structure in competition and to what extent could competitors adjust network structure so as to win the competition.

  18. DMEPOS Competitive Bidding

    Data.gov (United States)

    U.S. Department of Health & Human Services — The DMEPOS Competitive Bidding Program was mandated by Congress through the Medicare Prescription Drug, Improvement, and Modernization Act of 2003 (MMA). The statute...

  19. Competition Policy and Innovation

    DEFF Research Database (Denmark)

    Møllgaard, Peter; Lorentzen, Jo

    2005-01-01

    We briefly review the rationale behind technological alliances and provide a snapshot oftheir role in global competition, especially insofar as it is based around intellectual capital.They nicely illustrate the increased importance of horizontal agreements and thusestablish the relevance of the t......We briefly review the rationale behind technological alliances and provide a snapshot oftheir role in global competition, especially insofar as it is based around intellectual capital.They nicely illustrate the increased importance of horizontal agreements and thusestablish the relevance...... of the topic. We move on to discuss the organisation of industriesin a dynamic context and draw out consequences for competition policy. We concludewith an outlook on the underlying tensions between technology alliances, competitionpolicy, and industrial policy.JEL codes: L4, L5, O31Keywords: Competition...... policy, innovation, alliances, industrial policy...

  20. COMPETITIVENESS FOR SUSTAINABLE ECONOMIES

    Directory of Open Access Journals (Sweden)

    Nelu Eugen POPESCU

    2014-04-01

    Full Text Available The current economic environment puts pressure on all national economies which struggle to improve their competitiveness and innovativeness in a sustainable way. This article aims to present the current state of the competitiveness by reviewing the main literature and worldwide researches, in order to provide a brief overview of the determinants that drive productivity and economic success at global and national level, taking into consideration the entrepreneurial activity for a country’s competitiveness and economic growth. The paper identifies the ways in which efficiency driven countries can improve their policies and get a better return on their investments, underlining a set of competitiveness enhancing policies (measures that can be implemented by public and private institutions in order to strengthen the economic fundamentals of the economies.

  1. Innovation and strategic competitiveness

    Directory of Open Access Journals (Sweden)

    Jović Mile B.

    2003-01-01

    Full Text Available Paper discussed relationships of innovation to achieving strategic competitiveness in today globalized economic environment. Special attention is devoted to the nature of competitive advantages on global industries as well national level. Competitive advantage is a firm's ability to transform inputs into goods and services at a profit on a sustained basis, better than competitors. Comparative advantage resides in the factor endowments and created endowments of particular regions. Beside the traditional endowment approach (land, natural resources, labor and the size of the local population it is emphasized the importance of created one such as skilled labor, the technology and knowledge base, government support and culture. Creating corporate or country competitiveness roadmap there are no substantial difference - innovative as well strategic approach is essential.

  2. FameLab competition

    CERN Multimedia

    2011-01-01

    Are you 18 to 35 years old and studying or working in science in Switzerland? Are you passionate about your job and keen on exciting public imagination with a vision of the 21st century of science? Then this competition is for you!   For more information, check out http://www.famelab.ch/ or http://famelab.org/ or write to info@famelab.ch. Read more about the Famelab competition in this Bulletin article.  

  3. Technology and Competitiveness

    OpenAIRE

    Jan Fagerberg

    1995-01-01

    This paper reviews the literature on technology and competitiveness. First, the concept of the international competitiveness of a country, and various theoretical approaches on the relationship between trade and growth, are discussed. Then a number of empirical studies of the impact of technology (as evidenced by R&D, patents, etc.) on exports are examined. The final section summarizes the evidence and considers the lessons for policy.

  4. Managing Dynamic Competition

    OpenAIRE

    Tracy R. Lewis; Huseyin Yildirim

    2002-01-01

    In many important high-technology markets, including software development, data processing, communications, aeronautics, and defense, suppliers learn through experience how to provide better service at lower cost. This paper examines how a buyer designs dynamic competition among rival suppliers to exploit learning economies while minimizing the costs of becoming locked in to one producer. Strategies for controlling dynamic competition include the handicapping of more efficient suppliers in pr...

  5. Context Construction Through Competition

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    This article examines the relationship between the evolution of statehood and competition in the European context. To begin with, a particular take on the evolution of modern political power in the state form in Europe is developed. Against this background, the article reconstructs how the instit...... and to expand the use of competition as a tool for organizing social processes, and the implications of these attempts for the state of statehood....

  6. Context Construction through Competition

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    This paper examines the relation between the evolution of statehood and institutionalised competition in the European context. The first half of the paper develops a historical-sociological view on the evolution of modern political power in the state form in Europe while the second half the paper...... and expand the use of competition as a tool for organising social processes and the implications of the se attempts for the state of statehood....

  7. World competitiveness and agriculture

    Directory of Open Access Journals (Sweden)

    J. van Zyl

    1997-07-01

    Full Text Available Against the background of a changing environment in which market factors and greater world trade and competitiveness are increasingly becoming the only criteria for success, a framework for the analysis of world competitiveness is initially developed. This is followed by a discussion on the growth of productivity in agriculture, as well as an exposition of the role of agricultural research. Thirdly, price factors and the terms of trade are discussed, followed by a summary of policy implications.

  8. COMPETITION AS MARKET MECHANISM

    Directory of Open Access Journals (Sweden)

    N. Ya. Kazhuro

    2015-01-01

    Full Text Available The essence of a competition as an objective law for development of the commodities production based on private ownership of the means of production and commodity exchange has been revealed in the paper. The paper presents an economic basis of market economy (private ownership which generates a corresponding production objective. Such purpose is a maximization of profit and a minimization of market subject expenses. Therefore, a struggle for the most favourable conditions on commodity production and sales is inevitable in such situation. The struggle is considered in the community with developed market economy as a competition.The competition is regarded not as an exogenic factor exerting its influence on market economic system from the outside, but as an objective phenomenon which is inherent to management market system in itself. Such treatment is substantiated by economic disintegration of individual commodity producers. Being an important engine of market economy, the competition does not establish its laws, and its role is to be an executive of data which are internally inherent in commodity production laws and firstly it concerns a profit maximization law which defines a purpose and guiding motif of economic entities in the given economy.The competition plays a contradictory role under conditions of market economy. On the one hand, it makes manufacturers constantly to aspire to expense reduction for the sake of profit increase. This has resulted in labour productivity increase, production cost decrease and a company receives an opportunity to reduce retail price for its products. Consequently, the competition acts as a potential factor for lowering of prices while increasing production efficiency. On the other hand, sellers have more freedom in price fixing under conditions of imperfect competition as they sell their products under the conditions of a monopolistic competition or an oligopoly. This is the main weakest point of the market

  9. Global competitiveness research

    Directory of Open Access Journals (Sweden)

    Anđelić Slavica

    2016-01-01

    Full Text Available Wealth in all economies is being created at the microeconomic level through the activities of economic entities. Due to the disappearance of many barriers in international trade, i.e. reducing costs in transportation and communications, all countries and their economic subjects are now competing in the global market. In today's global economy, characterized by openness and integration, competitiveness plays a key role both in developed countries, as well as in developing ones. Competitiveness presents sustainable productivity growth driven by the quality of the strategy and operations of the company, affected by macroeconomic and microeconomic environment altogether. The level of competitiveness is determined by productivity - ability to produce goods and services using existing human, financial, natural and other resources. Productivity determines the standard of living of the country or a region, capital income, preservation of national wealth. Productivity also depends on the value of goods and services (e.g. of their uniqueness, quality and the efficiency of their production. In order to identify as many indicators (variables that are essential to the concept of competition, and get more reliable results when measuring the international competitiveness of countries, most commonly used and most accurate ones are three models: IMD model, the World Economic Forum model and the World Bank model. Those models have been successfully used by the CEER magazine, in order to conduct an analysis of competitiveness between Poland, the Czech Republic, Hungary, as well as of all developing countries (Serbia being among them.

  10. Competition in energy

    International Nuclear Information System (INIS)

    Haynes, Warren

    1995-01-01

    With changes occurring within both the gas and electricity industries and both sectors undergoing simultaneous reforms at the State and national levels it is timely to look at some major aspects of the energy-reform processes in Australia and to attempt to offer some perspectives from the viewpoint of an industry user of energy. From an industry user's viewpoint there is quantifiable evidence that competition in the energy sector will deliver major economic benefits to industry and the nation. The reform process currently in train will increase Australia's international competitiveness. Commonwealth-State collaboration is useful on economic issues which require a national consistent approach. Many significant and complex arrangement apply to the gas and electricity sectors which add to the complexity of the respective reform processes. More competitive arrangements are therefore required more quickly at several stages of the gas-sector reform process, such as in the commercialization of government utilities, resolving the issue of third-party transmission pricing, and the removal of State governments' impediments to competitive trading. The Hilmer Report on National Competition Policy will help deal with some difficult structural and transitional issues, e.g. third-party access, competitive structures, regulatory regimes, and a consistent national approach.(author). 1 fig., 1 photo

  11. MACROECONOMIC ASPECTS OF COMPETITIVENESS

    Directory of Open Access Journals (Sweden)

    Oleg Hooke

    2017-09-01

    Full Text Available In the process of globalization of world economic processes, the role of individual national economies increases, comparative advantages of the development of a country are formed, and their competitiveness is ensured. That is why it is worth emphasizing the importance of increasing the competitiveness of each individual country, based on its internal capacity. In a broad aspect, the competitiveness of the national economy is perceived as the ability of the country to ensure the balance of its external proportions and to avoid those constraints imposed by the foreign economic sphere, to self-organizing the improvement of their world economic ties. The competitiveness of the economy at the macro level is associated with the duration of the cycle of reproduction of the main productive assets and, accordingly, the jobs, productive forces of society and determined by the overall economic efficiency of investment. The criteria of competitiveness of the national economy are the growth of social productivity of labor, increase of social and economic efficiency of production and standard of living of the population. The competitiveness of the national economy determines sustainable socio-economic development of the country, as well as sustainable development predetermines the competitiveness of not only the country, but also all its levels. Scientific results are obtained using special methods of research of economic objects and phenomena, that is, based on the correlation and regressive, comparative analysis (establishing the relationship between the indicator factor, as well as economic modeling. Findings. Generalizing analysis and the importance of the macroeconomic aspect of competitiveness were used in the research paper, which will allow to better respond to the economic situation, in accordance with the trends of the “green” transformation of the economy; which in turn will solve important problems of the development and implementation of its

  12. Healthy Competition and Unsound Comparison: Reforming Educational Competition in Singapore

    Science.gov (United States)

    Christensen, Søren

    2015-01-01

    It is frequently claimed that the "competition state" responds to external competition by making competition increasingly central to its internal processes as well. This article discusses education reform in Singapore as departing from the opposite position. In Singapore "excessive" competition in education is now targeted by…

  13. Nursing: the hospital's competitive edge.

    Science.gov (United States)

    Shaffer, F A; Preziosi, P

    1988-09-01

    The health care marketplace is becoming increasingly competitive. The hospital has a built-in marketing force with the nursing department, because nurses are in constant, direct contact with the customer. Nursing must identify the case mix profile of the community and focus the hospital product lines to meet community needs. The nursing department should decentralize, change, measure, and innovate the staff mix needed to operationalize these product lines. The development of nursing practice standards for the case mix will help to identify the staff mix needed and create systems to efficiently manage the product lines. Nursing management must become aware of cross-subsidization and downward skill substitution of nursing personnel. Nursing information systems must generate quality reports that invoke cost consciousness on the part of nursing staff. Quality assurance programs must become unit based and complete with frequent audits to correlate length of stay with nursing quality. Correlations must be determined between nursing productivity and case mix to determine the hospital's niche in the marketplace. The transformation of health care into a competitive business industry has created many opportunities for nursing. The health care industry's incentives for efficiency along with the decreasing demand for inpatient hospital services will be the forces driving health care toward a competitive marketplace. The hospital's nursing department should be strategically positioned to become accountable for increasing market share and enhancing quality patient outcomes. The focus has shifted from the theoretical to the tactical, which is a step in the right direction, particularly for nursing. Nursing, if strategically positioned, will not only thrive but will also excel in this chaotic environment by capturing the opportunities and being innovative.

  14. SOCIAL ASPECTS OF COMPETITIVENESS

    Directory of Open Access Journals (Sweden)

    Klimova A. V.

    2014-06-01

    Full Text Available One of the most important conditions of the existence of every organization, every enterprise is to insure the long-term sustainable development, one of the conditions of which is the increase of an organizational competitiveness. In modern economic conditions, social aspects of competitiveness are now in the foreground of interest, because just the strategy of social responsibility (SSR of modern enterprises can assure some commercial benefits, in responding, at the same time, to the social demands and in creating its well-being. Such an approach is in the basis of the notion of competitiveness. Along with «rigid parameters», such as price characteristics, the capability to deal with competitors, effective financial and production policies, «flexible factors» of competitiveness are of a big importance: a personnel potential, individual and collective competencies, organizational and managerial capabilities. As a result, we have formulated a research hypothesis: the organizational competitiveness is defined by individual and collective competencies of an organization, is based on socially responsible actions, confirms the demand for the object and insures its sustainable long-term development. Any organization should base all its actions aimed to increase its competitiveness on its intellectual potential, or on the management of individual and collective competencies that assure the sustainable development and the goal achievement. For every organizational strategic action, an effective combination of these competencies exists. So, we suggest a new definition of competitiveness: it is a social and economic category of understanding of the social responsibility, having as a central element individual and collective competencies, based on socially responsible actions of an enterprise, insuring its long-term sustainable development.

  15. Political Failures and Intergovernmental Competition

    Directory of Open Access Journals (Sweden)

    Jean Hindriks

    2012-01-01

    Full Text Available In normative public economics, intergovernmental competition is usually viewed as harmful. Although empirical support for this position does not abound, market integration has intensified competition among developed countries. In this paper we argue that when assessing welfare effects of intergovernmental competition for various forms of political failures (the public choice critique, the outcome is ambiguous and competition can be welfare improving.

  16. Matrix models for quantifying competitive intransitivity.

    Science.gov (United States)

    Ulrich, Werner; Soliveres, Santiago; Kryszewski, Wojciech; Maestre, Fernando T; Gotelli, Nicholas J

    2014-09-01

    Assessing the relative importance of intransitive competition networks in nature has been difficult because it requires a large number of pairwise competition experiments linked to observed field abundances of interacting species. Here we introduce metrics and statistical tests for evaluating the contribution of intransitivity to community structure using two kinds of data: competition matrices derived from the outcomes of pairwise experimental studies ( C matrices) and species abundance matrices. We use C matrices to develop patch transition matrices ( P ) that predict community structure in a simple Markov chain model. We propose a randomization test to evaluate the degree of intransitivity from these P matrices in combination with empirical or simulated C matrices. Benchmark tests revealed that the methods could correctly detect intransitive competition networks, even in the absence of direct measures of pairwise competitive strength. These tests represent the first tools for estimating the degree of intransitivity in competitive networks from observational datasets. They can be applied to both spatio-temporal data sampled in homogeneous environments or across environmental gradients, and to experimental measures of pairwise interactions. To illustrate the methods, we analyzed empirical data matrices on the colonization of slug carrion by necrophagous flies and their parasitoids.

  17. EU POLICY REGARDING THE COMPETITIVENESS ISSUE

    Directory of Open Access Journals (Sweden)

    Maria Bârsan

    2004-07-01

    Full Text Available This article deals with one of the most important, but also challenging economic issues nowadays, which is economic competitiveness. The literature is not unanimous in recognizing the importance of competitiveness, especially where it concerns the state level. However, the relevance of international competitiveness is increasingly brought into light by theory, specific policy measures and by periodical evaluations made by international organizations. Against this background, the EU is one of the main players whose position is still lagging behind the USA, and, according to recent evaluations, behind the other OECD countries. The European Council in March 2000, held in Lisbon, had launched a very inciting challenge – that of transforming the EU economy into the most competitive and dynamic knowledge-based economy in the world, by 2010. Such an ambitious target requires an evaluation of the competitiveness level and also new measures to be taken in order to accomplish this objective.The article presents opinions on the EU competitiveness issue, and on the main weak and strong points, concluding that even the target and especially the schedule seem to be unrealistic, the new direction of action, i.e. towards better business conditions for enterprises being correct.

  18. Product-Market Competition in the Water Industry: Voluntarily Nondiscriminatory Pricing

    OpenAIRE

    Föllmi, Reto; Meister, Urs

    2002-01-01

    This paper presents an attempt to create competition in the water market by means of direct competition. We argue that the usual liberalisation device, competition for the market by franchise bidding, is problematic due to the particular features of the water industry. Our approach proposes the implementation of product market competition, i.e. competition in the market. In such a situation several water utilities using a single set of pipes compete for customers in the same area. Since the w...

  19. Marketing mix and competitiveness

    Directory of Open Access Journals (Sweden)

    Anđelković Slobodan

    2007-01-01

    Full Text Available Competitiveness cannot simply be viewed as a country's ability to export or generate trade surpluses, since these can be brought about at least temporarily by means of artificially lowering the exchange rate and/or compressing domestic expenditures, as has been done in recent years by many DC that have tried to adjust to diminished resource availability. Authors standpoint is that international competitiveness requires creating comparative advantage where it does not exist, and requires action on several levels including an emerging consensus on the importance of macroeconomic policy, role and accountability of the government as well as the imperative of developing and internalizing technology body of knowledge for achieving competitiveness. Particular attention is given to the role and impact of marketing instruments marketing mix.

  20. Price competition in procurement

    International Nuclear Information System (INIS)

    Keisler, J.M.; Buehring, W.A.

    1996-07-01

    When creating a private market to provide a public good, government agencies can influence the market's competitive characteristics. Markets have predictable, but often counterintuitive, behaviors. To succeed in applying available controls, and thereby reduce future costs, agencies must understand the behavior of the market. A model has been constructed to examine some issues in establishing competition for a structure in which there are economies of scale and government is obligated to purchase a fixed total quantity of a good. This model is used to demonstrate a way to estimate the cost savings from several alternative plans for a buyer exploring competitive procurement. The results are not and cannot be accurate for budgeting purposes; rather, they indicate the approximate magnitude of changes in cost that would be associated with changes in the market structure within which procurement occurs

  1. Context Construction through Competition

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    This paper examines the relation between the evolution of statehood and institutionalised competition in the European context. The first half of the paper develops a historical-sociological view on the evolution of modern political power in the state form in Europe while the second half the paper...... reconstructs how the institutionalisation of competition as a specific type of policy tool which has been used by emerging modern states to establish its authority vis-à-vis competing claims to authority. It furthermore engages in an examination of corporatist and governance based attempts to respectively curb...... and expand the use of competition as a tool for organising social processes and the implications of the se attempts for the state of statehood....

  2. Business plan competition

    CERN Multimedia

    2007-01-01

    "Venture – Companies for tomorrow" is a business plan competition, which supports students and other junior entrepreneurs in developing their business plans. The sixth edition of the competition is now taking place. Venture 2008 highlights: - prize money totalling CHF 150’000; - possibility to optimize business ideas and business plans with the help of experienced coaches: around 200 coaches are available, with a wide range of backgrounds, entrepreneurs as well as venture capitalists; -\tpossibility to present business ideas and business plans to potential investors ("Investor Days" - 17 January and 7 May); - active involvement in the start-up community; -\tcontribution to potential independence. The competition consists of two phases: Phase I, Business idea, Deadline for submission of business idea: 5 December 2007 (online at http://www.venture.ch). Award Ceremony: 17 January 2008 Phase II, Business plan Deadline for submission of business plan: 2 April 2008 (online at...

  3. Managing firm competitiveness in global markets

    NARCIS (Netherlands)

    Gehlhar, M.; Regmi, A.; Stefanou, S.E.; Zoumas, B.

    2006-01-01

    The globalization profile of US food firms is mixed. US sales from foreign direct investment is now over six times the level of exports, while US processed food trade balance has moved from +$9 billion in 1995 to - $7 billion in 2004. Competitive forces drive firms to seek new areas of growth, with

  4. Drivers of Competitiveness and Strategies for Economic ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Lessons from the crisis suggest that economies need to diversify their export base, increase competitiveness and invest in social institutions. This project will support capacity building, ... exports : a gravity analysis. Rapports. Developing inland China : do heterogeneous coastal foreign direct investments and exports help?

  5. Resource competition in plant invasions: emerging patterns and research needs

    Science.gov (United States)

    Gioria, Margherita; Osborne, Bruce A.

    2014-01-01

    Invasions by alien plants provide a unique opportunity to examine competitive interactions among plants. While resource competition has long been regarded as a major mechanism responsible for successful invasions, given a well-known capacity for many invaders to become dominant and reduce plant diversity in the invaded communities, few studies have measured resource competition directly or have assessed its importance relative to that of other mechanisms, at different stages of an invasion process. Here, we review evidence comparing the competitive ability of invasive species vs. that of co-occurring native plants, along a range of environmental gradients, showing that many invasive species have a superior competitive ability over native species, although invasive congeners are not necessarily competitively superior over native congeners, nor are alien dominants are better competitors than native dominants. We discuss how the outcomes of competition depend on a number of factors, such as the heterogeneous distribution of resources, the stage of the invasion process, as well as phenotypic plasticity and evolutionary adaptation, which may result in increased or decreased competitive ability in both invasive and native species. Competitive advantages of invasive species over natives are often transient and only important at the early stages of an invasion process. It remains unclear how important resource competition is relative to other mechanisms (competition avoidance via phenological differences, niche differentiation in space associated with phylogenetic distance, recruitment and dispersal limitation, indirect competition, and allelopathy). Finally, we identify the conceptual and methodological issues characterizing competition studies in plant invasions, and we discuss future research needs, including examination of resource competition dynamics and the impact of global environmental change on competitive interactions between invasive and native species. PMID

  6. Competition and social cohesion

    Directory of Open Access Journals (Sweden)

    Mario Libertini

    2014-03-01

    Full Text Available "Competition" and "social cohesion" are both protected by E.U. and Italian laws. The author moves from the analysis of the meaning of these two concepts, in order to reflect on their compatibility and the way to conciliate them. The central problem - in the opinion of the Author - is to abandon the myth of spontaneous markets' order and to rebuild a political order able to maintain and support, as far as possible, the competitive market economy, but also to govern economic processes in critical moments and situations.

  7. Competition in Soccer Leagues

    DEFF Research Database (Denmark)

    Hansen, Bodil Olai; Tvede, Mich

    In the present paper a model of competition between sports clubs in a sports league is presented. Clubs are endowed with initial players but at a cost clubs are able to sell their initial players and buy new players. The results are that: if the quality of players is one-dimensional, then equilib......In the present paper a model of competition between sports clubs in a sports league is presented. Clubs are endowed with initial players but at a cost clubs are able to sell their initial players and buy new players. The results are that: if the quality of players is one...

  8. Competitiveness in Road Transport

    DEFF Research Database (Denmark)

    Borgström, Benedikte; Gammelgaard, Britta; Bruun, Poul

    Road transport is an important sector, connecting time and space of production and consumption. Its market conditions has changed. The EU single market implementation has increased price pressure due to supply of low cost road freight transport from counties with lower cost structures. Changes...... a competitive value proposition? We will illustrate the strategy-as-practice with two projects, and discuss implications in terms of capabilities needed to create an effective value proposition and hence competitiveness. The theoretical contribution is in theorizing haulier strategic development in which we...

  9. Exploratory studies into strategies to enhance innovation-driven international competitiveness in a port context : Toward ambidextrous ports

    NARCIS (Netherlands)

    R.M.A. Hollen (Rick)

    2015-01-01

    markdownabstractResearch has highlighted that firms competing in dynamic environments have to balance exploitative (efficiency-directed) activities with explorative (innovation-directed) ones in order to remain internationally competitive. In economically advanced countries, whose competitiveness is

  10. Competitive intelligence as an enabler for firm competitiveness: An overview

    Directory of Open Access Journals (Sweden)

    Alexander Maune

    2014-06-01

    Full Text Available The purpose of this article is to provide an overview, from literature, about how competitive intelligence can be an enabler towards a firm’s competitiveness. This overview is done under the background of intense global competition that firms are currently experiencing. This paper used a qualitative content analysis as a data collection methodology on all identified journal articles on competitive intelligence and firm competitiveness. To identify relevant literature, academic databases and search engines were used. Moreover, a review of references in related studies led to more relevant sources, the references of which were further reviewed and analysed. To ensure reliability and trustworthiness, peer-reviewed journal articles and triangulation were used. The paper found that competitive intelligence is an important enabler of firm competitiveness. The findings from this paper will assist business managers to understand and improve their outlook of competitive intelligence as an enabler of firm competitiveness and will be of great academic value.

  11. Mathematics and Engineering in Real Life through Mathematical Competitions

    Science.gov (United States)

    More, M.

    2018-01-01

    We bring out an experience of organizing mathematical competitions that can be used as a medium to motivate the student and teacher minds in new directions of thinking. This can contribute to fostering research, innovation and provide a hands-on experience of mathematical concepts with the real world. Mathematical competitions can be used to build…

  12. Competition and the Performance of English Secondary Schools: Further Evidence

    Science.gov (United States)

    Levacic, Rosalind

    2004-01-01

    Both advocates of competition as a means to better school performance and economics-based research on this issue assume a direct relationship between a more competitive market structure (in terms of the number and concentration of schools in a local market) and better school performance. This is an application to schools of the…

  13. Competitiveness and Campaign '88.

    Science.gov (United States)

    Kernan-Schloss, Adam, Ed.; And Others

    This report profiles the positions of the six Democratic and six Republican 1988 presidential candidates on policy issues affecting U.S. competitiveness in the global economy. Candidate profiles are provided for: Bruce Babbitt, Michael Dukakis, Richard Gephardt, Albert Gore, Jr., Jesse Jackson, and Paul Simon (Democrats); and George Bush, Robert…

  14. Competition Fosters Trust

    DEFF Research Database (Denmark)

    Huck, Steffen; Ruchala, Gabriele K.; Tyran, Jean-Robert

    We study the effects of reputation and competition in a stylized market for experience goods. If interaction is anonymous, such markets perform poorly: sellers are not trustworthy, and buyers do not trust sellers. If sellers are identifiable and can, hence, build a reputation, efficiency quadruples...

  15. Business Ideas Competition

    CERN Multimedia

    2003-01-01

    Business Ideas Competition "The Rainbow Seed Fund is a UK fund, which provides finance to support the commercialization of good ideas founded on scientific research; it is for the benefit of the UK industry in particular. To encourage ideas from CERN the Rainbow Seed Fund is running a business ideas competition.The winner of this competition will receive an immediate cash prize of GBP £1,000. In addition the Rainbow Seed Fund may well provide finance for market research, for protection of Intellectual Property Rights (IPR) and for prototyping to take the idea forward. Further awards of GBP £750 will be made for ideas which gain investment from the Fund.Candidates will only be required to prepare a 2-4-page summary of their business idea, and not a full business plan. Full details and an entry form are available at www.rainbowseedfund.com ." ALL Members of the Personnel seeking participation in the business ideas competition are asked to submit their ideas via the CERN TT Unit (Jean-Marie.Le Goff@cern.ch) th...

  16. Conflict exposure and competitiveness

    NARCIS (Netherlands)

    Cecchi, Francesco; Leuveld, Koen; Voors, Maarten

    2016-01-01

    We use data from a street football tournament and a series of lab-in-field experiments in postconflict Sierra Leone to examine the impact of exposure to conflict violence on competitive behavior. We find that football players who experienced more intense exposure to violence are more likely to get a

  17. Industrial location and competitiveness

    NARCIS (Netherlands)

    S. Brakman (Steven); J.H. Garretsen (Harry); J.G.M. van Marrewijk (Charles)

    2006-01-01

    textabstractThe interaction between the extent of location advantages and the intensity of firm competition relative to the size of the market jointly determines the location of industrial activity. Technology, factor endowments, geography, and scale economies are influential for determining

  18. Explaining competitive reaction effects

    NARCIS (Netherlands)

    Leeflang, P.S.H.; Wittink, D.R.

    Changes in promotional expenditure decisions for a brand, as in other marketing decisions, should be based on the expected impact on purchase and consumption behavior as well as on the likely reactions by competitors. Purchase behavior may be predicted from estimated demand functions. Competitive

  19. Mediterranean Way of Competitiveness

    Directory of Open Access Journals (Sweden)

    Art Kovacic

    2010-12-01

    Full Text Available The Mediterranean area have a special concept of competitiveness topic. Normally is that region not so industrial and knowledge based oriented as a North Europe.That countries can't reach the same development level as the north one. Lisbon's and Goethenburg's strategies create the main framework of development programme. Mediterranean programme is such a case. European internal market has forced the EU countries to increase competitiveness. The economic prosperity of countries is associated with their ability to generate or attract economic activities which are able to increase income by performing well on themarket. Financial crisis in the EU has changed the look on the competitiveness research. Economy in the main countries has to find way of recovery. Former giants of the financial world have found themselves suddenly facing bankruptcy.Inevitably, the crisis is also having an effect on households and businesses - economic growth has slowed sharply and in some EU countries unemployment has begun to increase for the first time in several years. Form that perspective we have to find the right solution of European competitiveness.

  20. Competition Fosters Trust

    DEFF Research Database (Denmark)

    Huck, Steffen; Lünser, Gabriele; Tyran, Jean-Robert Karl

    2012-01-01

    We study the effects of reputation and competition in a trust game. If trustees are anonymous, outcomes are poor: trustees are not trustworthy, and trustors do not trust. If trustees are identifiable and can, hence, build a reputation, efficiency quadruples but is still at only a third of the fir...