Note: This page contains sample records for the topic donor immunoassay cedia from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results. Last update: November 12, 2013.
A preliminary initial cloned enzyme donorimmunoassay (CEDIA) was optimized for serum and urine drug testing with respect to the German per se limits for driving under the influence of drugs (serum) and lowered cut-offs in cases of driving licence re-granting (urine). The tests were performed on an Olympus AU 400 auto analyzer. Validation revealed sensitivities between 93% and 100% based on comparison with data from gas or liquid chromatography coupled with mass spectrometry. Even if specificity ranged between 83% and 98 %, the tests can be considered useful for forensic purposes. Receiver operating characteristic (ROC) curves, Youden indices, as well as positive and negative predictive values are presented. PMID:23386567
We report the determination of digoxin concentration in serum with Microgenics Cedia digoxin reagents on the Technicon CHEM 1. The Technicon CHEM 1 clinical chemistry analyzer has a throughput of 720 tests per hour and uses only 7 microliters each of two reagents. A 100 test kit can perform 2,640 tests. The within-run coefficient of variation (CV) range is 2.3-0.9% and the total CV is 6.3-2.9% at concentrations tested ranging from 1.10 to 2.94 ng/ml. The results of the Technicon CHEM 1 (y) assay correlated well with those by the Technicon RA 1000 system (x) with 31 clinical serum samples (y = -0.03 + 1.11x, r = 0.96). We concluded that the Cedia digoxin assay on the Technicon CHEM 1 provides a very cost-effective, precise, rapid, and accurate means to determine digoxin concentration in serum. PMID:7846748
Buprenorphine is a potent partial opioid agonist that is analyzed in urine to (i) monitor adherence to maintenance or detoxification therapy and (ii) detect illicit use. Buprenorphine analysis is commonly conducted on urine by immunoassay, but is subject to cross-reactivity from other drugs/drug metabolites, including morphine, codeine and dihydrocodeine. This study reports false-positive buprenorphine analysis [Thermo Fisher Scientific cloned enzyme donorimmunoassay (CEDIA)] in patients who denied unauthorized buprenorphine use prior to sampling, but who had been prescribed amisulpride. In two cases, confirmatory analysis by liquid chromatography-tandem mass spectrometry was negative (<0.5 µg/L) for buprenorphine and metabolites and positive for amisulpride. Although the cross-reactivity of amisulpride and sulpiride in the CEDIA buprenorphine assay is low (estimated at 0.003 and 0.002%, respectively), it remains a significant consideration given the likely high concentrations of these compounds in urine relative to the low cutoff of the buprenorphine assay. Neither amisulpride nor sulpiride was listed as potential sources of interference on the CEDIA data sheet when this work was performed. These findings highlight the importance of confirming immunoassay-positive buprenorphine results using a more selective analytical technique. PMID:23471956
Birch, M A; Couchman, L; Pietromartire, S; Karna, T; Paton, C; McAllister, R; Marsh, A; Flanagan, R J
FK506 (tacrolimus), a macrolide immunosuppressant, is widely used in pediatric transplant patients, but a relatively narrow therapeutic window in children vs adults requires close and accurate monitoring of whole blood FK506 levels. High-pressure liquid chromatography/tandem mass spectrometry (HPLC/MS/MS)-based assays have been viewed as the gold standard but are more time and labor intensive than cloned enzyme donorimmunoassay (CEDIA). To analyze differences between the 2 assays, we assayed FK506 in 348 split samples simultaneously by both methods. A further 70 samples were stratified by organ transplantation type: cardiac (13%), renal (23%), small bowel (22%), or liver transplantation (42%). Results were analyzed using standard statistical techniques for method comparison. CEDIA overestimated the FK506 value relative to HPLC/MS/MS by more than 20% in 40% of cases (139/348), whereas CEDIA underestimated the FK506 value relative to HPLC/MS/MS by more than 20% in 13.5% of cases, for a total inaccuracy of 53% using a ±20% cutoff. Only 28% of samples (99/348) measured by CEDIA were within 10% of the value obtained by HPLC/MS/MS. Bland-Altman analysis showed a mean bias of 9.5% in favor of CEDIA over HPLC/MS/MS (95% confidence interval, 6.1%-12.9%). Positive bias was greatest for liver transplant and R(2) values were lowest for intestinal transplant patients, indicating that HPLC/MS/MS may be a better option for this pediatric transplant subgroup. PMID:23690122
Urine buprenorphine screening is utilized to assess buprenorphine compliance and to detect illicit use. Robust screening assays should be specific for buprenorphine without cross-reactivity with other opioids, which are frequently present in patients treated for opioid addiction and chronic pain. We evaluated the new Lin-Zhi urine buprenorphine enzyme immunoassay (EIA) as a potentially more specific alternative to the Microgenics cloned enzyme donorimmunoassay (CEDIA) by using 149 urines originating from patients treated for chronic pain and opioid addiction. The EIA methodology offered specific detection of buprenorphine use (100%) (106/106) and provided superior overall agreement with liquid chromatography-tandem mass spectrometry, 95% (142/149) and 91% (135/149) using 5 ng/mL (EIA) and 10 ng/mL (EIA) cutoffs, respectively, compared to CEDIA, 79% (117/149). CEDIA generated 27 false positives, most of which were observed in patients positive for other opioids, providing an overall specificity of 75% (79/106). CEDIA also demonstrated interference from structurally unrelated drugs, chloroquine and hydroxychloroquine. CEDIA and EIA yielded similar sensitivities, both detecting 96% (22/23) of positive samples from patients prescribed buprenorphine, and 88% (38/43) and 81% (35/43), respectively, of all positive samples (illicit and prescribed users). The EIA methodology provides highly specific and sensitive detection of buprenorphine use, without the potential for opioid cross-reactivity. PMID:22417836
Melanson, Stacy E F; Snyder, Marion L; Jarolim, Petr; Flood, James G
The direct and simple detection of a broad spectrum of drugs in whole hemolysed postmortem blood (Part A) and the possibility of qualitative measurement in serum and whole blood using the cloned enzyme donor immu- noassay technique (CEDIA) (Part B) is described. We measured the samples for the presence of amphetamines (AMP), barbiturates (BARB), benzodiazepines (BENZ), cannabinoids, cocaine, LSD, methadone
Immunochemistry is a relatively new science that has developed rapidly in the last few decades. One of the most useful analytical developments associated with this new science is immunoassay. Originally immunoassays were developed in medical settings to facilitate the study of immunology, particularly the antibody-antigen interaction. Immunoassays now are finding widespread applications outside the clinical field because they are appropriate for a wide range of analytes ranging from proteins to small organic molecules. In the food analysis area, immunoassays are widely used for chemical residue analysis, identification of bacteria and viruses, and detection of proteins in food and agricultural products. Protein detection is important for determination of allergens and meat species content, seafood species identification, and detection of genetically modified plant tissues. While immunoassays of all formats are too numerous to cover completely in this chapter, there are several procedures that have become standard for food analysis because of their specificity, sensitivity, and simplicity.
We report that use of the popular analgesic tramadol can cause false-positive urine buprenorphine results. We examined the extent of tramadol cross-reactivity in three point-of-care urine buprenorphine immunoassays (ACON, QuikStrip, and ABMC) and an instrument-based one (Cedia). We tested 29 urine samples from patients known to be taking tramadol. Ten different samples tested positive for urine buprenorphine by at least one immunoassay. Samples with positive buprenorphine screens by immunoassay were tested for total buprenorphine and total norbuprenorphine content by liquid chromatography-tandem mass spectrometry (LC-MS-MS), which confirmed that seven of the 10 positive samples were false-positives. The remaining three positive immunoassay samples had insufficient quantity for LC-MS-MS testing. No false-positives were detected with the ACON (10 ng/mL calibration cutoff) or the Cedia assay (using a 20 ng/mL calibration cutoff). All four false-positive Cedia results (using a 5 ng/mL cutoff) in this study tested negative using the ACON device. Our data suggest that tramadol use can cause false-positive urine buprenorphine immunoassays, and this effect appears to be assay-dependent. Tramadol interference with the Cedia assay is clinically relevant, especially if the 5 ng/mL calibration cutoff is used. PMID:18544218
Shaikh, Salima; Hull, Mindy J; Bishop, Kenneth A; Griggs, David A; Long, William H; Nixon, Andrea L; Flood, James G
For most diverse purposes, different immunoassay (IA) screening methods are usually used to detect benzodiazepines and their metabolites in urine. In this study, we compared the main IAs used in forensic toxicology (Cloned Enzyme DonorImmunoassay, CEDIA(®); Enzyme-Multiplied Immunoassay Technique, EMIT(®); Fluorescent Polarization ImmunoAssay, FPIA(®); Kinetic Interaction of Microparticles in Solution, KIMS(®) and Immunochromatographic Techniques, IMC) with liquid chromatography-tandem mass spectrometry (LC-MS-MS). Twelve urine specimens were analyzed by 178 laboratories in Italy that participated in a National Proficiency Test, providing both qualitative and semi-quantitative results. Each IA was evaluated by the parameters: true positive, true negative, false positive (FP), false negative (FN), sensitivity (SENS), specificity (SPEC), positive predictive value, negative predictive value (NPV) and accuracy. SPEC was affected by a high FP rate for all IAs. The lowest SENS and NPV were provided by FPIA due to a high number of FN cases. Comparing IA semi-quantitative data with LC-MS-MS results, an overestimation of benzodiazepine amount is noted. This paper draws attention to the problem of the careless use of IA tests for forensic purposes as they may provide FP and/or FN results that can lead to errors of great severity. PMID:23943436
Bertol, Elisabetta; Vaiano, Fabio; Borsotti, Maurizio; Quercioli, Massimo; Mari, Francesco
Immunoassays were developed to determine the seroprevalence of antibody against human GB virus C (GBV-C). The antigenic target in each assay was a 44.6-kDa glycosylated protein representing the first 315 amino acids encoded by the GBV-C E2 gene. Sera or plasma were assayed for E2 antibody using an anti-human EIA format in which antigen-coated polystyrene beads were reacted with sample,
Sheng Lou; Xiaoxing Qiu; Gary Tegtmeier; Sandra Leitza; John Brackett; Kristen Cousineau; Amit Varma; Heidi Seballos; Samar Kundu; Steve Kuemmerlea; J. C. Hunt
Mycoplasma pneumoniae antibodies were studied in 504 blood donors and 102 patients with infections not caused by M. pneumoniae with the use of enzyme immunoassay kits from ThermoLabsystems (L), Savyon (S), Bio-Rad (B) and Novitec (N). Detection frequencies of M. pneumoniae IgM in blood donors were 14.9% (L), 16.0% (S), 2.8% (B) and 3.8% (N), and in patients were 40.2% (L), 42.2% (S), 9.8% (B) and 16.7% (N). Detection frequencies of M. pneumoniae IgA were 68.5% (L) and 22.8% (S), and in 65 respiratory disease patients were 100% (L) and 53.8% (S). Thus, use of some kits may lead to overdiagnosis of M. pneumoniae infections. PMID:15606638
The University of Glasgow Department of Pathological Biochemistry has recently made available five immunoassay animations that draw on the interactivity of the FutureSplash plug-in (discussed in the December 20, 1996 issue of the Scout Report). The animations are "a learning resource for students, to show the wide application of the use of antibodies in a clinical biochemistry laboratory," and are "graphical representations of the immunoassay methodology used by a number of commercial manufacturers." Each immunoassay is presented as a series of animations, allowing the user to navigate forward and back in time. A key is provided, and animations can be viewed step by step (with explanations) and then replayed as a single continuous animation without explanations or navigation. Immunoassay Animations is a powerful visual teaching tool.
Immunoassays have broad applications for a wide variety of important biological compounds and environmental contaminants. Immunoassays can detect the presence of an antigen in the human body, a pollutant in the environment, or a critical antibody in a patient?s serum to develop a...
The use of microfluidic chips for immunoassays has been extensively explored in recent years. The combination of immunoassays and microfluidics affords a promising platform for multiple, sensitive, and automatic point-of-care (POC) diagnostics. In this review, we focus on the description of recent achievements in microfluidic chips for immunoassays categorized by their detection method. Following a brief introduction to the basic principles of each detection method, we examine current microfluidic immunosensor detection systems in detail. We also highlight interesting strategies for sensitive immunosensing configurations, multiplexed analysis, and POC diagnostics in microfluidic immunosensors.
Although most clinical laboratories use microscopy and routine O&P procedures when identifying parasitic infections, there are several parasites that are better detected through serological means. Toxoplasma, Giardia, and Cryptosporidium were discussed along with immunoassays used for their detection. Immunoassays provide quick results and are less labor intensive than specimen concentration and slide preparation for microscopic examination. These assays are easy to use and provide sensitive and specific results. Some clinical laboratories no longer perform O&Ps in house and refer specimens to reference laboratories for evaluation. By using immunoassays, some of the more common parasites can be identified in a timely manner reducing turn-around times. Some controversy exists over the use of IIF and EIA tests used for ANA testing along with measuring CRPs and PCT as predictors of bacterial sepsis and septic shock. Regardless of the methodology discussed in this series of articles, there are pros and cons to the various immunoassays available. Determining the most appropriate assay based on patient population and volume is governed by the institution and its patients' needs. In conclusion, immunoassays, whether manual or automated, are easy to use, cost effective and allow the medical laboratory professional to provide quick and accurate results to the clinician so the most appropriate treatment can be administered to the patient. The ultimate goal of healthcare professionals is to provide the highest quality of medical care in a timely manner. The use of immunoassays in the clinical laboratory allows the healthcare team to successfully achieve this goal. PMID:22953520
Immunoassays have evolved for a broad range of applications since the pioneering work of Yalow and Berson who developed the first competitive radioimmunoassay (RIA) for human insulin in 1959. Immunoassay detection of specific antigens and host-produced antibodies directed against such antigens consitutes one of the most widely used and successful methods for diagnosing infectious diseases (IDs). The number and variety of new assay systems that are continually being developed reflect the increasing demand for immunoassays possessing greater sensitivity, speed, and ease of use. This trend has been driven, in part, by the need for improved immunodiagnostic systems to perform rapid testing and counter emerging IDs and biothreat (BT) agents. Another factor driving this trend is the need to integrate immunoassays with more sensitive nucleic acid-based methods for a comprehensive approach. Here we examine the development of immunoassays, some of the key formats used for the detection and identification of BT/ID agents, and the application of these technologies under different scenarios. PMID:14579751
Andreotti, Peter E; Ludwig, George V; Peruski, Anne Harwood; Tuite, James J; Morse, Stephen S; Peruski, Leonard F
A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic s...
This article takes a special focus on signal amplification technologies in immunoassays and new generations of lateral-flow assays. Novel signal amplification technologies based either on new classes of biofunctional nanocrystals consisting of releasable fluorophores or on aggregation-induced emission (AIE) can improve the sensitivity and the limits of detection in immunoassays. A bio-barcode assay also allows signal amplification by utilizing antibody-coated magnetic beads to concentrate the analytes and antibody-coated gold nanoparticle probes to carry with a large number of oligonucleotides. These innovative technologies boost the development of immunoassays. Growth in rapid immunoassay is fueled by the increasing number of diabetics, the globalization of infectious diseases and the surge in cardiovascular and other chronic diseases as well as other chronic conditions. Rapid, near patient, decentralized, point-of-care (POC) tests are emerging as a tool for more efficient diagnosis and patient evaluation. Technological innovations in lateral-flow assays have enabled a move to bring testing closer to the patient. A novel "digital-style" lateral-flow assay provides semi-quantitative results by simply counting the number of red lines in the test without any expensive reading instrument. An immuno-threshold-based assay can give a signal directly proportional to the concentration of a hapten to prevent confusion on interpretation of the test results. In addition, POC tests become more meaningful to healthcare professionals by combining the benefits of new technologies to provide quantitative results. A molecular compact disc provides a high-resolution imaging capability that can identify and quantify many different antigens simultaneously in highly complex immunoassays. Further advances in immunoassays will bring diagnostic testing even closer to the patient, and can help physicians to monitor diseases that require immediate test results, thereby enhancing the quality of patient care. PMID:17874052
Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.
Nelson, Randall W (Phoenix, AZ); Williams, Peter (Phoenix, AZ); Krone, Jennifer Reeve (Granbury, TX)
Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.
Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve
Highly efficient FRET leads to important enhancements for homogeneous immunoassays. By using the novel phosphorescent dye EuLH and BHQ-10 as a donor-acceptor pair, the FRET efficiency increases to >99.5?%, leading to significantly improved signal-to-background ratio, precision and linear range. The phosphorescence detection enabled full compatibility to serum samples for this fast-responding immunoassay. PMID:23532940
Chemiluminescence (CL) detection offers potential for high sensitivity immunoassays (CLIAs). Several approaches were attempted to automate CL measurements. Those include the use of photographic film, clear microtitration plates, and magnetic separation. We describe a photon counting detection apparatus that performs (CLIA) measurements. The CL detector moves toward a disposable reaction vessel to create a light-tight seal and then triggers and integrates a CL signal. The capture uses antibody coated polystyrene microparticles. A porous matrix, which is a part of a disposable reaction tray, entraps the microparticle-captured reaction product. The CL signal emanated off the immune complex immobilized by the porous matrix is detected. The detection system is a part of a fully automated immunoassay analyzer. Methods of achieving high sensitivities are discussed.
Khalil, Omar S.; Mattingly, G. P.; Genger, K.; Mackowiak, J.; Butler, J.; Pepe, C.; Zurek, T. F.; Abunimeh, N.
The progressive understanding and improvement of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS), realized over the years through the considerable efforts of Dr. Marvin Vestal, have made possible numerous comparable efforts involving its application in the biological sciences. Here we revisit the concepts behind one such analytical approach, Mass Spectrometric Immunoassay, which is designed to selectively detect and quantify proteins present in biological milieu.
The Federal Workplace Drug Testing Program changed urine screening and confirmation cutoff concentrations for opiate testing from 300 to 2000 ng/mL in 1998. Morphine was the designated target compound. An additional heroin metabolite, 6-acetylmorphine (6-AM), was added to the testing procedure with a cutoff concentration > or = 10 ng/mL. Testing of 6-AM was required if morphine was positive to assist in medical review. A comparison of the new opiate cutoff concentrations was made with the older cutoff concentration at 300 ng/mL. Six commercial opiate immunoassays, four with a 300-ng/mL cutoff, ONLINE, EMIT, CEDIA and AxSym, and two with 2000-ng/mL cutoffs, ONLINE and EMIT, were selected to test 920 urine samples collected from 11 male human subjects following single doses of heroin. Eight received intravenous doses of 3, 6, and 12 mg heroin HCl and four smoked 3.5-, 5.2-, 10.5-, or 13.9-mg doses of heroin (base). In addition, 183 urine-based blind quality-control specimens were added to the study set to assess linearity, cross-reactivity, and interference. Total morphine, free morphine, and 6-AM were measured in each sample by gas chromatography-mass spectrometry (GC-MS). Linearity, cross-reactivity, and interference results for each immunoassay are described. Detection times, sensitivity, specificity, and efficiency of each assay were determined using data from the specimens collected after heroin administration. Detection times for morphine using the 300-ng/mL cutoff assays was approximately 12 h for low dose and 24 to 48 h for higher doses of heroin. For the two 2000-ng/mL cutoff concentration assays detection time was about 12 h. This was also the detection time for 6-AM by GC-MS. ONLINE had the lowest sensitivity, 60-74%, highest specificity, 98.8-100%, and least interference from a selection of common over-the-counter drugs and opioids. Increasing the cutoff to 2000 ng/mL from 300 ng/mL increased efficiencies of the assays from 72.7 to 82.6% to over 97%. PMID:11043654
Smith, M L; Shimomura, E T; Summers, J; Paul, B D; Nichols, D; Shippee, R; Jenkins, A J; Darwin, W D; Cone, E J
A new, general method of immunoassay is demonstrated. The approach is based on the microscale immunoaffinity capture of target antigens followed by mass-specific identification and quantitation using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Immunoaffinity capture of antigens effectively overcomes signal suppression effects typically encountered during traditional matrix-assisted laser desorption/ionization analysis of complex biological mixtures while simultaneously concentrating the analyte into a small volume. Sample incubation and processing methods were such that a typical analysis could be performed in less than 1 h while subnanomolar sensitivities were maintained. The technique has been used for the rapid, selective, and quantitative screening of human blood for the presence of myotoxin a, and Mojave toxin from the venoms of the prairie rattlesnake, Crotalus virdis virdis, and the Mojave rattlesnake, Crotalus scutulatus scutulatus. 18 refs., 8 figs.
Nelson, R.W.; Krone, J.R.; Bieber, A.L.; Williams, P. [Arizona State Univ., Tempe, AZ (United States)
An immunoassay technique capable of detecting and identifying a number of species of microorganisms in a single analysis is described. The method uses optical-resonance size discrimination of microspheres to identify antibodies to which stained microorganisms are bound.
Whitten, W. B.; Shapiro, M. J.; Ramsey, J. M.; Bronk, B. V.
\\u000a There is a continuously increasing demand for the specific and sensitive determination of trace amounts of analytes in complex\\u000a matrices for various purposes. In this respect, immunoassays and immunosensors that rely on antibodyantigen binding provide\\u000a a promising approach of analysis for their remarkable specificity and sensitivity. High specificity of immunoassays and immunosensors\\u000a is achieved solely by the molecular recognition of
A newly developed homogeneous enzyme immunoassay for the determination of netilmicin in serum was evaluated and compared with a radioenzymatic assay. A total of 102 serum samples from patients treated with netilmicin were measured by both methods. This comparison showed an excellent correlation (r = 0.993). The enzyme immunoassay has proved to be precise, accurate, and specific. Because of its rapidity and the ease of performance, this method is a useful alternative to current assays for monitoring serum netilmicin concentrations.
... Games > Donor Tag Game Printable Version Donor Tag Game This feature requires version 6 or later of ... Needles Blood Donor Community Donor Stories Recipient Stories Games Facebook Fanbox Avatars and Badges Banners eCards Twitter ...
A micro-analytical platform for performing electrophoresis-based immunoassays was developed by integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device. The microfluidic immunoassays are performed by gel electrophoretic s...
A simple, rapid, and highly sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) and disposable screen-printed electrodes (SPE) has been developed to detect polychlorinated biphenyls (PCBs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PCB-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PCB (HRP-PCB). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreactions among PCB-antibody-coated MBs, PCB analyte, and HRP-PCB. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing o-aminophenol and hydrogen peroxide for electrochemical detection. The different parameters, including the amount of HRP-PCB conjugates, immunoreaction time, and the concentration of substrate that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 5 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical immunoassay was successfully evaluated with untreated river water spiked with PCBs, and the results were validated by commercial PCB enzyme-linked immunosorbent assay kit, indicating that this convenient and sensitive technique offers great promise for decentralized environmental application and trace PCBs monitoring.
Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe
Stimulated by the achievements of the first phase in genomics and the resulting need of assigning functions to the acquired sequence information, novel formats of immunoassays are being developed for high- throughput multi-analyte studies. In principle, they are similar in nature to the microarray assays already established at the level of nucleic acids. However, the biochemical diversity and the sheer
... My Donor Family Newsroom Minorities Contacting My Donor Family Writing anything can be a challenge. Staring at ... down to write a note to your donor family can feeling overwhelming. The good news is that ...
A new homogeneous chemiluminescent immunoassay method featuring the use of specific binding members separately labeled with an acridan-based chemiluminescent compound and a peroxidase is reported. Formation of an immunocomplex brings the chemiluminescent compound and the peroxidase into close proximity. Without any separation steps, a chemiluminescent signal is generated upon addition of a trigger solution, and the intensity is directly correlated to the quantity of the analyte. PMID:23477541
Akhavan-Tafti, Hashem; Binger, Dean G; Blackwood, John J; Chen, Ying; Creager, Richard S; de Silva, Renuka; Eickholt, Robert A; Gaibor, Jose E; Handley, Richard S; Kapsner, Kenneth P; Lopac, Senja K; Mazelis, Michael E; McLernon, Terri L; Mendoza, James D; Odegaard, Bruce H; Reddy, Sarada G; Salvati, Michael; Schoenfelner, Barry A; Shapir, Nir; Shelly, Katherine R; Todtleben, Jeff C; Wang, Guoping; Xie, Wenhua
Abstract Antibodies that recognize chelated forms of metal ions have been used to construct immunoassays for Cd(II), Hg(II), Pb(II), and Ni(II). In this paper, the format of these immunoassays is described and the binding properties of three monoclonal antibodies direc...
Background: Traditionally prevention of transfusion-transmitted viral infections relies on screening blood donors using enzyme immunoassays (EIA). To further enhance blood safety some countries employ anti-HBc testing to detect HBsAg negative donors. Improving safety is further complemented by genome screening using nucleic acid amplified technology (NAT). Aim of study: to determine whether there is a need to reform our strategy for
Nureddin A. Doghman; Muftah Y. Ali; Fatma I. Najem
Immunoassay is a very specific, sensitive, and widely applicable analytical technique. Recent advances in genetic engineering have led to the development of monoclonal antibodies which further improves the specificity of immunoassays. Originally, radioisotopes were used to label the antigens and antibodies used in immunoassays. However, in the last decade, numerous types of immunoassays have been developed which utilize enzymes and fluorescent dyes as labels. Given the technical, safety, health, and disposal problems associated with using radioisotopes, immunoassays that utilize the enzyme and fluorescent labels are rapidly replacing those using radioisotope labels. These newer techniques are as sensitive, are easily automated, have stable reagents, and do not have a disposal problem. 6 refs., 1 fig., 2 tabs.
Two different methods for preventing the binding of cross-reacting antibodies to the genus-reactive chlamydial lipopolysaccharide (LPS) were used to improve the specificity of an enzyme immunoassay for the determination of antibodies to Chlamydia trachomatis. Coated elementary bodies were treated with either sodium periodate, to oxidize the antigenic sites of the LPS, or Triton X-100, to extract the LPS. By using these new enzyme immunoassays, the standard enzyme immunoassay, and the whole inclusion fluorescence (WIF) assay, antibodies to C. trachomatis were determined in sera from different groups of patients and controls. Paired serum samples from patients with culture-proven urogenital C. trachomatis infections showed similar responses in all three assays. Paired serum samples from patients with Chlamydia psittaci infections showed similar responses in the WIF assay and the standard enzyme immunoassay, whereas significantly reduced titers were obtained in the enzyme immunoassays with treated antigen, especially in the convalescent-phase serum samples. Serum samples from patients with symptoms suggestive of infection with C. trachomatis, pregnant women, and blood donors were evaluated by all three types of assays. Eighty percent of the significant reductions in immunoglobulin G (IgG), IgA, and IgM titers were observed in sera with WIF assay titers in the lower classes (IgG, 1: < or = 256; IgA, 1: < or = 32; IgM, 1: < or = 16). From these results we conclude that oxidation of the antigen by sodium periodate is a simple and effective method of producing an enzyme immunoassay with enhanced specificity that could be useful for diagnostic purposes and seroepidemiological studies.
Ossewaarde, J M; de Vries, A; van den Hoek, J A; van Loon, A M
Novel designs of integrated fluidic microchips allow separations, chemical reactions, and calibration-free analytical measurements to be performed directly in very small quantities of complex samples such as whole blood and contaminated environmental samples. This technology lends itself to applications such as clinical diagnostics, including tumor marker screening, and environmental sensing in remote locations. Lab-on-a-Chip based systems offer many *advantages over traditional analytical devices: They consume extremely low volumes of both samples and reagents. Each chip is inexpensive and small. The sampling-to-result time is extremely short. They perform all analytical functions, including sampling, sample pretreatment, separation, dilution, and mixing steps, chemical reactions, and detection in an integrated microfluidic circuit. Lab-on-a-Chip systems enable the design of small, portable, rugged, low-cost, easy to use, yet extremely versatile and capable diagnostic instruments. In addition, fluids flowing in microchannels exhibit unique characteristics ('microfluidics'), which allow the design of analytical devices and assay formats that would not function on a macroscale. Existing Lab-on-a-chip technologies work very well for highly predictable and homogeneous samples common in genetic testing and drug discovery processes. One of the biggest challenges for current Labs-on-a-chip, however, is to perform analysis in the presence of the complexity and heterogeneity of actual samples such as whole blood or contaminated environmental samples. Micronics has developed a variety of Lab-on-a-Chip assays that can overcome those shortcomings. We will now present various types of novel Lab- on-a-Chip-based immunoassays, including the so-called Diffusion Immunoassays (DIA) that are based on the competitive laminar diffusion of analyte molecules and tracer molecules into a region of the chip containing antibodies that target the analyte molecules. Advantages of this technique are a reduction in reagents, higher sensitivity, minimal preparation of complex samples such as blood, real-time calibration, and extremely rapid analysis.
Weigl, Bernhard H.; Hatch, Anson; Kamholz, Andrew E.; Yager, Paul
... about the steps involved in finding a matching bone marrow donor . HLA matching Human leukocyte antigen (HLA) typing is used to match you with a donor for your bone marrow or cord blood transplant. Learn more about how ...
The rhetorical advantages and dangers involved in casting the students as "future donors" are explained. The way in which the institutions have to change for casting its students as future donors is described.
The ES 300 (Boehringer Mannheim Diagnostics, Indianapolis, IN) is a new automated immunoassay analyzer intended for the quantitative determination of a wide range of analytes. We compared its performance to enzyme immunoassay (EIA), fluorescence polarization immunoassay (FPIA), and radioimmunoassay (RIA) methods for cortisol, digoxin, ferritin, prolactin, T4-uptake, total-T3, and TSH. The ES 300 methods showed excellent precision and the manufacturers' linearity claims were met in all cases. Cortisol, prolactin, total-T3, and TSH showed no bias and acceptable correlation with other methods. Digoxin, ferritin and total T4 showed positive bias but acceptable correlation. The ES 300 T4-uptake correlated poorly with the TDx method and showed positive bias; however, these assays appear comparable (although deficient) in diagnostic sensitivity when compared to TSH and T4 data for the same patient population. In all, we found the ES 300 to be an acceptable instrumental alternative for the high volume immunoassay laboratory. PMID:1525980
Camara, P D; Velletri, K; Krupski, M; Rosner, M; Griffiths, W C
The goal of the National Marrow Donor Program (NMDP) in utilizing this Navy grant was to recruit and type at least 46,000 new unrelated potential marrow donors for inclusion in the National Marrow Donor Program's Registry. Specifically, it was anticipated...
Immunoassays are routinely used in the screening of commodities and foods for fungal toxins (mycotoxins). Demands to increase speed and lower costs have lead to continued improvements in such assays. Because many reported mycotoxins are low molecular weight (below 1 kDa), immunoassays for their detection have generally been constructed in competitive heterogeneous formats. An exception is fluorescence polarization immunoassay (FPIA), a homogeneous format that does not require the separation of bound and free labels (tracer). The potential for rapid, solution phase, immunoassays has been realized in the development of FPIA for many of the major groups of mycotoxins, including aflatoxins, fumonisins, group B trichothecenes (primarily deoxynivalenol), ochratoxin A, and zearalenone. This review describes the basic principles of FPIA and summarizes recent research in this area with regard to mycotoxins.
A sensitive enzyme immunoassay for plasma betamethasone was developed using betamethasone-3-(O-carboxymethyl)oxime-beta-D-galactosidase conjugate as a labelled antigen and 4-methylumbelliferyl-beta-D-galactoside as a fluorescence substrate. The performances of the enzyme immunoassay were compared with that of a radioimmunoassay using /sup 3/H-betamethasone and the same antiserum. The minimal detectable level for the enzyme immunoassay was 0.15 pg/tube or 0.15 ng/ml of plasma, which was remarkably more sensitive than the radioimmunoassay level of 10 pg/tube or 2 ng/ml of plasma. The specificity was sufficient, in particular, the cross reactivity of cortisol as 0.008%. However, the precision of the enzyme immunoassay was inferior to that of the radioimmunoassay.
Kominami, G.; Yamauchi, A.; Ishihara, S.; Kono, M.
The project demonstrated that the combination of chemiluminescent (CL) acridinium esters and monoclonal antibodies to Candida cell-wall mannan is capable of generating a simple non-isotopic immunoassay for Candida mannan in serum. The sensitivity of the i...
The newest formulation of the Syva EMIT assay for drugs of abuse, EMIT II, and a new immunoassay, OnLine (Roche), utilizing the kinetic interaction of microparticles in solution (KIMS) methodology, RIA tests, and TDx fluorescence polarization immunoassay (FPIA) procedures were compared for marijuana, cocaine, opiates, and barbiturates. Both EMIT II and OnLine immunoassays were performed with a Hitachi 717 analyzer. Calibration curves, the degree of separation between negative and cutoff calibrators, precision, likelihood of carryover from positive to negative samples, and overall ease and speed of analysis were evaluated. RIA and OnLine detected 99% of gas chromatography/mass spectrometry (GC/MS)-confirmed marijuana samples; TDx, 95%; and EMIT II, 88%. All four immunoassays detected approximately 99% of confirmed cocaine-positive urines. RIA, OnLine, and TDx all detected 100% of opiate-confirmed samples; EMIT II, 97%. Barbiturate assays exhibited the greatest disparity, with OnLine and TDx detecting 100% of confirmed positives; EMIT II, 88%; and RIA, 78%. For a variety of reasons, we prefer the fully automated EMIT II and OnLine assays for high-volume urine testing, in comparison with our laboratory's semiautomated RIA tests and the limited-throughput TDx system. The four immunoassays investigated delivered comparable performance in terms of detection rates for GC/MS-confirmed positives for some drugs but not for others. PMID:8403399
Armbruster, D A; Schwarzhoff, R H; Hubster, E C; Liserio, M K
The shifting ideological winds of foreign aid donors have driven their policy towards governments in poor countries. Donors supported state-led development policies in poor countries from the 1940s to the 1970s; market and private-sector driven reforms during the 1980s and 1990s; and returned their attention to the state with an emphasis on
In an attempt to gain insight into the motivations of blood donors and nondonors, two paper and pencil questionnaires were developed and mailed to approximately 7,000 individuals. In response, 1,429 nondonors and 200 donors completed and returned usable q...
B. C. Leibrecht J. M. Hogan G. A. Luz K. I. Tobias
Examining the charitable behavior of 56,663 US households, this paper evaluates the distinctive characteristics of educational donors as compared with donors to noneducational charitable organizations and with nondonors. In general, educational donors had significantly greater income, wealth, and education than other donors. Educational donors
Laparoscopic donor nephrectomy (LDN) has numerous advantages over open donor nephrectomy. The cosmetic issues and pain that arise due to the 5 to 6-cm incisions on the abdominal wall in LDN have led to transvaginal laparoscopic donor nephrectomy (TVLDN). Between May and August 2012, we performed seven donor nephrectomies via a transvaginal approach. The mean age of the donors was 53.0 ± 9.52 years. The mean operative time was 97.29 ± 39.47 minutes and mean warm ischemia time, 220.71 ± 55.49 seconds. Donors were mobilized, began oral intake at 8 hours postoperative, and were all discharged within the first 24 hours. Except one dose of analgesic applied immediately after the operation, no additional medication was required. No infectious complications were encountered in any recipient. TVLDN may be a good alternative for female donors. Compared with LDN, TVLDN has benefits of less postoperative pain, faster recovery, shorter hospital stay, and excellent cosmetic results. PMID:23622577
Bayer HealthCare LLC, Diagnostics Division has developed a new third-generation assay for the detection of antibodies to hepatitis C (anti-HCV) in human serum and plasma on the ADVIA Centaur immunoassay system. This assay employs magnetic particle separation technology with direct chemiluminescence for optimal assay performance. The assay is fully automated, requires a sample volume of 10 microl and has a throughput of up to 120 tests per hour. The ADVIA Centaur HCV2 Assay was tested with samples from HCV-infected individuals, blood donors, and hospitalized patients in an extensive performance evaluation at two sites in Europe in order to generate performance data in support of obtaining the Communautés Européennes (CE) mark for European market distribution. The HCV performance evaluation resulted in an overall diagnostic specificity of 99.9% and a diagnostic sensitivity of 100%. Assay performance evaluation, using HCV seroconversion performance panels, resulted in comparable or better results when compared to the comparison assay (Abbott AxSYM3 HCV Version 3.0 Assay). Data from the performance evaluation demonstrate that the ADVIA Centaur HCV Assay is a specific and sensitive automated immunoassay for detection of antibodies to hepatitis C virus with performance that is comparable to that of currently marketed assays. Additionally, this assay has the advantage of being on the ADVIA Centaur immunoassay system, which provides the flexibility of high throughput and full automation. PMID:15000223
Denoyel, Gérard; van Helden, Josef; Bauer, Richard; Preisel-Simmons, Barbara
The practice of immunoassay has experienced a widespread transition from radioisotopic labeling to nonisotopic labeling over the last two decades. Radioisotope labels have drawbacks that hamper their applications: (i) perceived radiation hazards of reagents, (ii) regulatory requirements and disposal problems of working with radioactive materials, and (iii) short shelf-life of the labeled reagents. The advantage of isotopic labeling is the incorporation into analytes without altering structure or reactivity, as is often the case with ELISA or fluorescent detection systems. We developed a format for isotope label immunoassay with the long-life isotope 14C as the label and accelerator mass spectrometer (AMS) as the detection system. AMS quantifies attomole levels of several isotopes, including 14C. With this exquisite sensitivity, the sensitivity of an immunoassay is limited by the Kd of the antibody and not the detection system. The detection limit of the assays for atrazine and 2,3,7,8-tetrachlorodibenzo-p-dioxin was 2.0 × 10?10 M and 2.0 × 10?11 M, respectively, approximately an order of magnitude below the standard enzyme immunoassay. Notably, <1 dpm (0.45 pCi) of 14C-labeled compound was used in each assay, which is well below the limit of disposal (50 nCi per g) as nonradioactive waste. Thus, endogenous reporter ligands quantified by AMS provide the advantages of an RIA without the associated problems of radioactive waste.
Shan, Guomin; Huang, Wei; Gee, Shirley J.; Buchholz, Bruce A.; Vogel, John S.; Hammock, Bruce D.
Urinary excretion of nitrophenol metabolites is an important index of human exposure to organophosphate pesticides. In particular, p-nitrophenol, a major urinary metabolite of parathion, can be used as a biomarker of human exposure. Immunoassay methods have been recently describe...
An enzyme-immunoassay was developed to measure the concentration of serum antibody specific for the secretory antigens released by migrating toxocaral larvae. This technique was evaluated by testing sera from healthy UK adults, and from patients with and without toxocariasis. In 922 healthy adults, 2.6% were found to have elevated specific antibody levels. Elevated values were observed twice as frequently in
The use of fine magnetic particles as labels for antibodies and the measurement of their remanent magnetization for the preparation of immunoassays is presented. Antibodies were coupled with magnetic nanoparticles and samples were prepared by reaction of the magnetically labeled antibodies with their solid phase adsorbed antigen. After exposing the samples to a field of some mT a dc-SQUID system
R. Kotitz; H. Matz; L. Trahms; H. Koch; W. Weitschies; T. Rheinlander; W. Semmler; T. Bunte
Four pentachlorophenol (PCP) enzyme immunoassays for environmental analysis have been evaluated through the U.S. EPA Superfund Innovative Technology Evaluation (SITE) program. Three assays were formatted for on-site field use and one assay could be used in a field laboratory sett...
Antibodies to atrazine were labelled with glucose oxidase and used in colorimetric enzyme linked immunosorbent assays. Transparent aminosilanized indium tin oxide coated glass electrodes were derivatized with aminodextran covalently modified with atrazine caproic acid. The labelled antibodies were used to investigate the derivatized electrodes colorimetrically and the electrodes were use in an electrochemiluminescence flow injection analyser. Electrochemiluminescence immunoassay for atrazine
Robert Wilson; Michael H. Barker; David J. Schiffrin; Ram Abuknesha
... instructions before and after surgery Have a compatible blood type Have an emotional tie with the recipient Not ... test is to find out if the donor's blood type matches the recipients blood type. Next, the transplant ...
The introduction of living donor liver transplantation (LDLT) has been one of the most remarkable steps in the field of liver transplantation (LT). First introduced for children in 1989, its adoption for adults has followed only 10?years later. As the demand for LT continues to increase, LDLT provides life-saving therapy for many patients who would otherwise die awaiting a cadaveric organ. In recent years, LDLT has been shown to be a clinically safe addition to deceased donor liver transplantation (DDLT) and has been able to significantly extend the scarce donor pool. As long as the donor shortage continues to increase, LDLT will play an important role in the future of LT.
Nadalin, S.; Bockhorn, M.; Malago, M.; Valentin-Gamazo, C.; Frilling, A.
In this study, a fluorescence resonance energy transfer (FRET)-based quantum dot (QD) immunoassay for detection and identification of Aspergillus amstelodami was developed. Biosensors were formed by conjugating QDs to IgG antibodies and incubating with quencher-labeled analytes; QD energy was transferred to the quencher species through FRET, resulting in diminished fluorescence from the QD donor. During a detection event, quencher-labeled analytes are displaced by higher affinity target analytes, creating a detectable fluorescence signal increase from the QD donor. Conjugation and the resulting antibody:QD ratios were characterized with UV-Vis spectroscopy and QuantiT protein assay. The sensitivity of initial fluorescence experiments was compromised by inherent autofluorescence of mold spores, which produced low signal-to-noise and inconsistent readings. Therefore, excitation wavelength, QD, and quencher were adjusted to provide optimal signal-to-noise over spore background. Affinities of anti-Aspergillus antibody for different mold species were estimated with sandwich immunoassays, which identified A. fumigatus and A. amstelodami for use as quencher-labeled- and target-analytes, respectively. The optimized displacement immunoassay detected A. amstelodami concentrations as low as 103 spores/mL in five minutes or less. Additionally, baseline fluorescence was produced in the presence of 105 CFU/mL heat-killed E. coli O157:H7, demonstrating high specificity. This sensing modality may be useful for identification and detection of other biological threat agents, pending identification of suitable antibodies. Overall, these FRET-based QD-antibody biosensors represent a significant advancement in detection capabilities, offering sensitive and reliable detection of targets with applications in areas from biological terrorism defense to clinical analysis.
Kattke, Michele D.; Gao, Elizabeth J.; Sapsford, Kim E.; Stephenson, Larry D.; Kumar, Ashok
In this study, a fluorescence resonance energy transfer (FRET)-based quantum dot (QD) immunoassay for detection and identification of Aspergillus amstelodami was developed. Biosensors were formed by conjugating QDs to IgG antibodies and incubating with quencher-labeled analytes; QD energy was transferred to the quencher species through FRET, resulting in diminished fluorescence from the QD donor. During a detection event, quencher-labeled analytes are displaced by higher affinity target analytes, creating a detectable fluorescence signal increase from the QD donor. Conjugation and the resulting antibody:QD ratios were characterized with UV-Vis spectroscopy and QuantiT protein assay. The sensitivity of initial fluorescence experiments was compromised by inherent autofluorescence of mold spores, which produced low signal-to-noise and inconsistent readings. Therefore, excitation wavelength, QD, and quencher were adjusted to provide optimal signal-to-noise over spore background. Affinities of anti-Aspergillus antibody for different mold species were estimated with sandwich immunoassays, which identified A. fumigatus and A. amstelodami for use as quencher-labeled- and target-analytes, respectively. The optimized displacement immunoassay detected A. amstelodami concentrations as low as 10(3) spores/mL in five minutes or less. Additionally, baseline fluorescence was produced in the presence of 10(5) CFU/mL heat-killed E. coli O157:H7, demonstrating high specificity. This sensing modality may be useful for identification and detection of other biological threat agents, pending identification of suitable antibodies. Overall, these FRET-based QD-antibody biosensors represent a significant advancement in detection capabilities, offering sensitive and reliable detection of targets with applications in areas from biological terrorism defense to clinical analysis. PMID:22163961
Kattke, Michele D; Gao, Elizabeth J; Sapsford, Kim E; Stephenson, Larry D; Kumar, Ashok
An exploratory effort to selectively detect the presence of a nitrifying bacterium, Nitrosomonas europaea, successfully demonstrated the fundamental utility of an enzyme-based immunoassay protocol. The applied polyclonal antibody test seemingly offered a marked improvement over the available analytical options, including plating, activity, and fluorescence immunoassay techniques. Following an initial purification step to enhance overall specificity, this procedure had an apparent lower limit of detection of ?5 × 106 cells per ml. Tests conducted with activated sludge samples exhibited a distinct difference between nitrifying and nonnitrifying mixed liquors, although the highest Nitrosomonas levels observed (i.e., at 1 to 2% of the overall viable cell density) were relatively close to the latter detection boundary.
An immunoassay system based on enzyme immunoassay technology has been developed for quantitative panel testing. The system includes test card disposables, reagents, and an instrument. Patients' samples are processed semiautomatically in the instrument with minimum user intervention. The test card has multiple test areas at individual locations on a membrane solid phase so that simultaneous determinations from a single specimen are possible. Each panel also includes positive and negative reagent procedural controls. Factory-determined calibration curves for each analyte are provided in barcode form with each test kit. The reagents include a specimen dilution buffer, enzyme conjugate, and precipitogenic substrate. Up to 10 test cards at a time can be processed in random-access and continuous-access modes, with automated agitation of sample and reagents over the solid phase, temperature-controlled incubation, and membrane washing and reading, data reduction, and printout of results. The optical reader measures diffuse reflectance and features source intensity and wavelength compensation. PMID:2673584
Donohue, J; Bailey, M; Gray, R; Holen, J; Huang, T M; Keevan, J; Mattimiro, C; Putterman, C; Stalder, A; Defreese, J
ProtoPharm makes use of the ProtoChip, a high-density immunoassay system, to construct epitope fingerprints of complex protein mixtures. Unlike all other protein biochip methods, the ProtoChip does not require the immobilization of proteins or antibodies on a solid support nor does the ProtoChip require the purification of large numbers of proteins. The ProtoChip may be used to profile complex protein
A heterologous enzyme immunoassay for serum androstenediol (Adiol: 3?, 17?-dihydroxy-androst-5-ene) was established. The combination of anti-Adiol antiserum raised in rabbit against Adiol 7-O-(carboxymethyl)oxime (Adiol 7-CMO) conjugated bovine serum albumin (Adiol 7-CMO-BSA) and Adiol 7-iminomethylcarboxylic acid conjugated alkaline phosphatase was used for the assay. The sensitivity of the heterologous assay system was superior to that of a homologous assay system in
Immunoassays are presently used worldwide for the rapid screening of drugs. Despite the fact that they are a highly valuable\\u000a tool for the testing of legal and illicit drugs, there is a real risk of false-positive and false-negative findings and many\\u000a pitfalls must be taken into account when these tests are used in an uncritical manner and without valid confirmation
Harald Schütz; Alexandre Paine; Freidoon Erdmann; Günter Weiler; Marcel A. Verhoff
The founding and growth of Syva Company is examined in the context of its leadership role in the development of homogeneous immunoassays. The simple mix and read protocols of these methods offer advantages in routine analytical and clinical applications. Early homogeneous methods were based on insensitive detection of immunoprecipitation during antigen/antibody binding. The advent of reporter groups in biology provided a means of quantitating immunochemical binding by labeling antibody or antigen and physically separating label incorporated into immune complexes from free label. Although high sensitivity was achieved, quantitative separations were experimentally demanding. Only when it became apparent that reporter groups could provide information, not only about the location of a molecule but also about its microscopic environment, was it possible to design practical non-separation methods. The evolution of early homogenous immunoassays was driven largely by the development of improved detection strategies. The first commercial spin immunoassays, developed by Syva for drug abuse testing during the Vietnam war, were followed by increasingly powerful methods such as immunochemical modulation of enzyme activity, fluorescence, and photo-induced chemiluminescence. Homogeneous methods that quantify analytes at femtomolar concentrations within a few minutes now offer important new opportunities in clinical diagnostics, nucleic acid detection and drug discovery.
Immunoassay techniques may represent useful screening tools to assist analysts interested in the presence and amounts of organic toxicants in biological fluids. The widespread application of immunoassay methods in medicinal and forensic (drugs of abuse) chemistry has resulted in such screening methodologies. Four methodologies of potential benefit are considered: the free radical assay technique, the enzyme-mediated immunoassay technique, radioimmunoassay, and hemagglutination. Each of these immunoassays is based on the competitive displacement of the labeled drug (or toxicant) from the antibody complex by the unlabeled drug-toxicant in the sample.
|When times get tough, grown children often turn to their parents for help--for some extra cash, even somewhere to stay. For colleges and universities, that role is filled by alumni donors. In 2011, with education budgets slashed across the country, giving accounted for 6.5 percent of college expenditures, according to the Council for Aid to
Using a clinical case, this paper explores the ethical complexities of assessing potential living organ donors when the proposed donor-recipient pair consists of monozygotic (identical) or dizygotic (fraternal) twins. While all donor-recipient pairs can present various ethical and psychosocial challenges, the challenges of twin pairs are unique and especially complex. Donor Advocate Teams need to be aware of these unique issues and address them during their assessment process. PMID:17302603
The objectives of this study were to evaluate and compare the performance of the deceased donor registries of the 50 states and the District of Columbia and to identify possible predictive factors of donor designation. Data were collected retrospectively by Donate Life America using a questionnaire sent to Donor Designation Collaborative state teams between 2007 and 2010. By the end of 2010, there were 94,669,081 designated donors nationwide. This accounted for 39.8 per cent of the U.S. population aged 18 years and over. The number of designated organ donors and registry-authorized recovered donors increased each year; however, the total number of recovered donors in 2010 was the lowest since 2004. Donor designation rate was significantly higher when license applicants were verbally questioned at the Department of Motor Vehicles (DMV) regarding their willingness to register as a donor and when DMV applicants were not given an option on DMV application forms to contribute money to support organ donation, compared with not being questioned verbally, and being offered an option to contribute money. State registries continue to increase the total number of designated organ donors; however, the current availability of organs remains insufficient to meet the demand. These data suggest that DMV applicants who are approached verbally regarding their willingness to register as a donor and not given an option on DMV application forms to contribute money to support organ donation might be more likely to designate themselves to be a donor. PMID:23461946
Hajhosseini, Babak; Stewart, Bryan; Tan, Jane C; Busque, Stephan; Melcher, Marc L
Text VersionPage 1. This document is one component of the donor history questionnaire documents (Version No. ... Full-Length Donor History Questionnaire ... More results from www.fda.gov/downloads/biologicsbloodvaccines/bloodbloodproducts
The incidence of blood donors seropositive for Trypanosoma cruzi in North America has increased with population migration and more rigorous surveillance. The United States, considered nonendemic for T. cruzi, could therefore be at risk to exposure to parasite transmission through blood or organ donations. Current tests show variable reactivity, especially with Central American sera. Here we describe the development of a lateral flow immunoassay for the rapid detection of T. cruzi infection that has a strong correlation to the radioimmunoprecipitation assay (RIPA) gold standard in the United States. Such a test could have utility in small blood banks for prescreening donors, as well as in cardiac transplantation evaluation. T. cruzi consensus and/or RIPA-positive sera from Central and South America were evaluated in enzyme immunoassays (EIAs). These included commercial panels from Boston Biomedica, Inc. (BBI) (n = 14), and HemaBio (n = 21). Other sources included RIPA-positive sera from the American Red Cross (ARC) (n = 42), as well as from Chile. Sera were tested with the multiepitope recombinant TcF. All but one of the BBI samples were positive and 7 of 21 HemaBio samples and 6 of 42 ARC samples were low positive or negative. This observation indicated the need for additional antigens. To complement TcF reactivity, we tested the sera with peptides 30, 36, SAPA, and 1.1, 1.2, and 1.3 His fragments of 85-kDa trans-sialidase. We identified a promising combination of the tested antigens and constructed a single recombinant protein, ITC6, that enhanced the relative sensitivity in U.S. blood donor sera compared to that of TcF. The data on its evaluation using RIPA-confirmed positive sera in EIA and lateral flow immunoassay studies are presented, along with an additional recombinant protein, ITC8.2, with two additional sequences for peptide 1 and Kmp-11. The latter, when evaluated in a dipstick assay with consensus positive sera, had a sensitivity of 99.2% and a specificity of 99.1%.
Houghton, Raymond L.; Stevens, Yvonne Y.; Hjerrild, Kathryn; Guderian, Jeff; Okamoto, Masahiko; Kabir, Mazbahul; Reed, Steven G.; Leiby, David A.; Morrow, W. John W.; Lorca, Myriam; Raychaudhuri, Syamal
The incidence of blood donors seropositive for Trypanosoma cruzi in North America has increased with population migration and more rigorous surveillance. The United States, considered nonendemic for T. cruzi, could therefore be at risk to exposure to parasite transmission through blood or organ donations. Current tests show variable reactivity, especially with Central American sera. Here we describe the development of a lateral flow immunoassay for the rapid detection of T. cruzi infection that has a strong correlation to the radioimmunoprecipitation assay (RIPA) "gold standard" in the United States. Such a test could have utility in small blood banks for prescreening donors, as well as in cardiac transplantation evaluation. T. cruzi consensus and/or RIPA-positive sera from Central and South America were evaluated in enzyme immunoassays (EIAs). These included commercial panels from Boston Biomedica, Inc. (BBI) (n = 14), and HemaBio (n = 21). Other sources included RIPA-positive sera from the American Red Cross (ARC) (n = 42), as well as from Chile. Sera were tested with the multiepitope recombinant TcF. All but one of the BBI samples were positive and 7 of 21 HemaBio samples and 6 of 42 ARC samples were low positive or negative. This observation indicated the need for additional antigens. To complement TcF reactivity, we tested the sera with peptides 30, 36, SAPA, and 1.1, 1.2, and 1.3 His fragments of 85-kDa trans-sialidase. We identified a promising combination of the tested antigens and constructed a single recombinant protein, ITC6, that enhanced the relative sensitivity in U.S. blood donor sera compared to that of TcF. The data on its evaluation using RIPA-confirmed positive sera in EIA and lateral flow immunoassay studies are presented, along with an additional recombinant protein, ITC8.2, with two additional sequences for peptide 1 and Kmp-11. The latter, when evaluated in a dipstick assay with consensus positive sera, had a sensitivity of 99.2% and a specificity of 99.1%. PMID:19211772
Houghton, Raymond L; Stevens, Yvonne Y; Hjerrild, Kathryn; Guderian, Jeff; Okamoto, Masahiko; Kabir, Mazbahul; Reed, Steven G; Leiby, David A; Morrow, W John W; Lorca, Myriam; Raychaudhuri, Syamal
Familial Parkinson disease (PD) can result from ?-synuclein gene multiplication, implicating the reduction of neuronal ?-synuclein as a therapeutic target. Moreover, ?-synuclein content in human cerebrospinal fluid (CSF) represents a PD biomarker candidate. However, capture-based assays for ?-synuclein quantification in CSF (such as by ELISA) have shown discrepancies and have limited suitability for high-throughput screening. Here, we describe two sensitive, in-solution, time-resolved Förster's resonance energy transfer (TR-FRET)-based immunoassays for total and oligomeric ?-synuclein quantification. CSF analysis showed strong concordance for total ?-synuclein content between two TR-FRET assays and, in agreement with a previously characterized 36 h protocol-based ELISA, demonstrated lower ?-synuclein levels in PD donors. Critically, the assay suitability for high-throughput screening of siRNA constructs and small molecules aimed at reducing endogenous ?-synuclein levels was established and validated. In a small-scale proof of concept compound screen using 384 well plates, signals ranged from <30 to >120% of the mean of vehicle-treated cells for molecules known to lower and increase cellular ?-synuclein, respectively. Furthermore, a reverse genetic screen of a kinase-directed siRNA library identified seven genes that modulated ?-synuclein protein levels (five whose knockdown increased and two that decreased cellular ?-synuclein protein). This provides critical new biological insight into cellular pathways regulating ?-synuclein steady-state expression that may help guide further drug discovery efforts. Moreover, we describe an inherent limitation in current ?-synuclein oligomer detection methodology, a finding that will direct improvement of future assay design. Our one-step TR-FRET-based platform for ?-synuclein quantification provides a novel platform with superior performance parameters for the rapid screening of large biomarker cohorts and of compound and genetic libraries, both of which are essential to the development of PD therapies.
Bidinosti, Michael; Shimshek, Derya R.; Mollenhauer, Brit; Marcellin, David; Schweizer, Tatjana; Lotz, Gregor P.; Schlossmacher, Michael G.; Weiss, Andreas
Serum specimens collected from patients convalescing from acute measles or mumps infections, other viral infections, or rheumatoid arthritis and from blood donors were tested in indirect and reverse assays for measles and mumps immunoglobulin M (IgM) antibodies. All the samples from patients convalescing from acute mumps and measles infections gave positive IgM results in both tests. However, 6% of sera from patients recovering from other viral infections, 68.4% of sera from patients with rheumatoid arthritis, and 5.6% of sera from normal blood donors gave false-positive results by the indirect measles IgM enzyme immunoassay (EIA). By the indirect mumps IgM EIA, 9% of sera from other viral infections, 70.1% of sera from patients with rheumatoid arthritis, and 5.6% of sera from normal blood donors gave false-positive reactions. The reverse test system for measles IgM gave false-positive results in 1.5% of sera from the group with other viral infections, and the reverse mumps EIA gave false-positive results in 0.9% of the patients. Other sera groups did not react in either measles or mumps reverse IgM assays. The results indicated that although nonspecific reactions are frequent in indirect IgM tests for viral antibodies, such reactions are rarely encountered when reverse IgM EIA tests are employed.
This article reviews recent advances in nanomaterial labels in electrochemical immunosensors and immunoassays. Various nanomaterial labels are discussed, including colloidal gold/silver, semiconductor nanoparticles, and markers loaded nanocarriers (carbon nanotubes, apoferritin, silica nanoparticles, and liposome beads). The enormous signal enhancement associated with the use of nanomaterial labels and with the formation of nanomaterialantibody-antigen assemblies provides the basis for ultrasensitive electrochemical detection of disease-related protein biomarkers, biothreat agents, or infectious agents. In general, all endeavors cited here are geared to achieve one or more of the following goals: signal amplification by several orders of magnitude, lower detection limits, and detecting multiple targets.
Antibodies to atrazine were labelled with glucose oxidase and used in colorimetric enzyme linked immunosorbent assays. Transparent aminosilanized indium tin oxide coated glass electrodes were derivatized with aminodextran covalently modified with atrazine caproic acid. The labelled antibodies were used to investigate the derivatized electrodes colorimetrically and the electrodes were use in an electrochemiluminescence flow injection analyser. Electrochemiluminescence immunoassay for atrazine in the range 0-10 ppb showed that it was possible to detect less than 0.1 ppb, the precautionary limit for pesticides in drinking water recommended by the European Commission. PMID:9178513
Wilson, R; Barker, M H; Schiffrin, D J; Abuknesha, R
Immunoassays are very sensitive and efficient tests that are commonly used to identify a specific protein. Examples of applications in the food industry include identification of proteins expressed in genetically modified foods, allergens, or proteins associated with a disease, including celiac disease. This genetic disease is associated with Europeans and affects about one in every 200 people in North America. These individuals react immunologically to wheat proteins, and consequently their own immune systems attack and damage their intestines. This disease can be managed if wheat proteins, specifically "gliadins," are avoided in foods.
An enzyme immunoassay for usnic acid in lichens was developed, the sensitivity of which was 0.1 microg/g of air-dried material (0.00001%). Polyclonal rabbit antibodies against bovine serum albumin conjugated to (+)-usnic acid under the conditions of formaldehyde condensation made it possible to determine the analyzed substance in solutions at concentrations from 1 ng/mL when it interacts with an immobilized gelatin conjugate homologous in the binding mode. Usnic acid in 2-26600 microg/g (0.0002-2.6%) amounts was found in all 236 studied samples of lichens belonging to 53 species and 8 families. PMID:23882952
In this review outlines are given on various types of enzyme immunoassay. The applications to such enzyme immunoassays, especially ELISA, are dealth with in detail. It is concluded that these techniques have high sensitivity and will be suitable in due course as routine laboratory tests.
Immunoassays are analytical methods based on specific antibodies directed to a particular target analyte. The binding between antibody and analyte can be used for detection and quantitation. Immunoassay can provide a sensitive, specific, simple to perform, and cost-effective analysis for many compounds of environmental concern (Van Emon et al. 1989). Methods can be designed for rapid, field-portable, semiquantitative analysis or
To meet the needs of a global community, an immunoassay for cryptococcal antigen (CrAg) must have high sensitivity for CrAg of all major serotypes. A new immunoassay for CrAg in lateral flow format was evaluated and found to have a high sensitivity for detection of serotypes A, B, C, and D. PMID:23365202
Gates-Hollingsworth, Marcellene A; Kozel, Thomas R
To meet the needs of a global community, an immunoassay for cryptococcal antigen (CrAg) must have high sensitivity for CrAg of all major serotypes. A new immunoassay for CrAg in lateral flow format was evaluated and found to have a high sensitivity for detection of serotypes A, B, C, and D.
Bayer HealthCare LLC, Diagnostics Division, has developed a new third-generation assay for the detection of antibodies to HIV 1, including group O, and HIV 2 in human serum and plasma on the ADVIA Centaur immunoassay system. The ADVIA Centaur HIV 1/O/22 Assay employs magnetic particle separation technology with direct chemiluminescence for optimal assay performance. The assay is fully automated, requires a sample volume of 50 microl and has a throughput of up to 120 tests per hour. The ADVIA Centaur HIV 1/O/2 Assay was tested in an extensive performance evaluation at two sites in Europe. Samples from HIV-1 and HIV-2 infected individuals, blood donors, hospitalized patients, and high-risk individuals were utilized to generate performance data in support of obtaining the Communautés Européennes (CE) mark for European market distribution. The comparison assay for the performance evaluation was the Abbott AxSYM HIV 1+2 gO Assay. The performance evaluation resulted in an overall diagnostic specificity of 99.9 % and a diagnostic sensitivity of 100%. Assay performance was further evaluated using HIV seroconversion panels. Equivalent results were obtained when the ADVIA Centaur HIV 1/O/2 Assay was compared to the comparison assay. The performance evaluation data demonstrate that the ADVIA Centaur HIV 1/O/2 Assay is a specific and sensitive automated immunoassay for detection of antibodies to HIV-1, including group O, and HIV-2 with performance that is comparable to that of currently marketed assays. Additionally, the ADVIA Centaur HIV 1/O/2 Assay has the advantage of being on an immunoassay system, which provides the flexibility of high throughput and full automation. PMID:15000224
van Helden, Josef; Denoyel, Gérard; Freeman, Jim; Preisel-Simmons, Barbara
Most American donor insemination programs include a policy of complete confidentiality concerning the donor of the semen. This is the result of a long legal tradition of American constitutional law. However, some slight abridgement of this body of legal decisions might be very much in the best interests of children arising from donor insemination, and even--in most cases, in fact--the donors themselves. With regard to the children, the factors involved are both those of genetic counseling, should the need arise, and psychological development. Of course, as at present, the donor must be relieved of all responsibility, both legal and financial. PMID:8348162
The aim of this paper is to report the first case of atomoxetine leading to false-positive urine drug screen. An otherwise healthy 27-year-old female with a history of attention deficit hyperactivity disorder (ADHD) treated with atomoxetine had an acute onset tonic-clonic seizure. On arrival to the hospital, a urine toxicological drug screen with immunochemical cloned enzyme donorimmunoassay (CEDIA) was performed. Results were positive for amphetamines; however, the presence of these substances could not be confirmed with urine gas chromatography-mass spectrometry (GC-MS). She denied any illicit drug use, herbal medications, or supplements, and her other prescription medications have not been previously known to cause a false-positive result for amphetamines. While stimulant treatments for ADHD could certainly result in a positive result on urine screen for amphetamines, there have been no reports of false-positive results for amphetamines secondary to patients using atomoxetine. We implicate atomoxetine, and/or its metabolites, as a compound or compounds which may interfere with urine drug immunoassays leading to false-positive results for amphetamines CEDIA assays.
Fenderson, Joshua L.; Stratton, Amy N.; Domingo, Jennifer S.; Matthews, Gerald O.; Tan, Christopher D.
An assay for the anticonvulsant drug phenobarbital (PB) has been developed that is based on the principles of the substrate-labeled fluorescent immunoassay. A fluorogenic enzyme substrate, galactosyl umbelliferone, was covalently linked to a derivative of PB. The labeled drug, galactosyl umbelliferone-PB (GUPB), is nonfluorescent under conditions of the assay; however, hydrolysis of the galactosyl moiety by bacterial beta-galactosidase yields a fluorescent product. When GUPB is bound by antibody to PB, it is not a substrate for enzymatic hydrolysis. Thus, only GUPB not bound to antibody is hydrolyzed. In competitive binding reactions, using a fixed concentration of GUPB and a limiting amount of antibody, the PB in serum and the GUPB compete for antibody-binding sites. The fluorescence produced upon enzymatic hydrolysis of unbound GUPB is directly proportional to the concentration of PB. Unknown serum levels of PB are determined from a standard curve of fluorescent intensity versus standard PB concentrations. The assay is specific, sensitive, and easy to perform. It is carried out by adding the equivalent of 2 microliters of serum standard or unknown directly to a cuvette containing 3 ml of a buffered solution of antibody and enzyme. One-hundred microliters of GUPB is added, and the fluorescence intensity is measured after a fixed time (any time from 5 to 90 min). Using clinical specimens, our assay correlated well with a commercial enzyme immunoassay (correlation coefficient = 0.97) and had an interassay precision of less than 7%. PMID:7013165
Living donor renal allograft survival is superior to that achieved from deceased donors, although graft outcome is suboptimal in some of these patients. In an effort to identify the subset of patients at high risk for poor outcomes we studied donor risk factors in 248 living kidney donor-recipient pairs. Unadjusted donor (125)I-iothalamate GFR (iGFR), donor age more than 45 years, donor total cholesterol level less than 200 mg/dL, and donor systolic blood pressure (SBP) less than 120 mm Hg were correlated with allograft estimated glomerular filtration rate (eGFR), and incidence of acute rejection (AR), delayed graft function and/or graft loss at 2 years posttransplantation. Donor iGFR less than 110 mL/min (slope=-7.40, P<0.01), donors more than 45 years (slope=-8.76, P<0.01), donor total cholesterol levels more than 200 mg/dL (slope=-10.03, P<0.01), and SBP more than 120 mm Hg (slope=-5.60, P=0.03) were associated with lower eGFR. By multivariable linear regression analysis these variables remained independently associated with lower eGFR, and poorer outcomes. The increasing number of donor factors (age, iGFR, cholesterol, and blood pressure) was directly associated with worse posttransplant eGFR (P<0.01). In conclusion, our data suggest that routine assessment of living donor parameters could supplement the consideration of recipient characteristics in predicting posttransplant risk of graft injury/dysfunction. PMID:17353780
Issa, Naim; Stephany, Brian; Fatica, Richard; Nurko, Saul; Krishnamurthi, Venkatesh; Goldfarb, David A; Braun, William E; Dennis, Vincent W; Heeger, Peter S; Poggio, Emilio D
Recently, we have developed a prototype magnetic immunoassay system using a high temperature superconductor (HTS) superconducting quantum interference device (SQUID) to investigate the performance and usability of the magnetic immunoassay. In this study, we improved the immunoassay system to heighten the sensitivity of the immunoassay measurement. To reduce the SQUID-to-sample distance, we introduced a structure to compensate for thermal shrinkage
A. Tsukamoto; K. Saitoh; N. Sugita; H. Kuma; Y. Sugiura; S. Hamaoka; N. Hamasaki; K. Enpuku
Since its creation in 1993, hemovigilance has an important place for blood safety. The part concerning donors, as the name suggests, targeted on improvement of donor's safety covers in fact the two points of the transfusion chain with serious adverse events in donor, epidemiologic survey for recipients and post-donation information on the two sides. Organized management and close collaboration between the actors of the transfusion chain are necessary to ensure the effectiveness of the system. PMID:23587614
The LIAISON thyroid hormone assays TSH, FT4, FT3, T4 and T3 were evaluated by determining the imprecision, the reference ranges, the functional sensitivity (TSH), the dilution characteristics (accuracy) (FT4, FT3), and the recovery after spiking (TSH, T4, T3). Furthermore, inter-method comparisons were performed with following methods: Elecsys (Roche Diagnostics; TSH), AxSYM (Abbott Diagnostics; TSH, FT4, FT3, T4), ACS:180 (Bayer Diagnostics; all analytes), Amerlex-M (Johnson & Johnson; T4) and LISO-Phase (Techno Genetics; FT4). The fully automated LIAISON random access analyser is based on microparticle immunoassays and chemiluminescence. The coefficients of variation (CV) of intra-assay imprecision were between 0.2-6.0%, except for the control sample with extremely low TSH concentrations and low T3 concentrations. Inter-assay imprecision was performed by measuring controls covering the measuring range over a period of 9 to 20 days, with CVs ranging from 2.3-16.0%. The suitability of the sample material was determined by analysing serum and samples treated with EDTA, citrate or heparin in parallel. The results showed good correlations of the thyroid hormone concentrations between serum and plasma samples except for LIAISON FT3, for which lower results were observed with EDTA-plasma. The regression analysis of correlation studies gave slopes from 0.849 to 0.957 for TSH, from 1.023 to 1.375 for FT4, from 0.670 to 0.911 for FT3, from 0.917 to 1.166 for T4 and 1.00 for T3 depending on the concentration range and the method of comparison. The LIAISON FT4 assay showed a trend towards higher values in the high concentration range when compared with the ACS:180. The ranges of thyroid hormone concentrations determined in serum taken from apparently healthy subjects were found to be in accordance with published data. The clinical sample study confirmed that the LIAISON thyroid hormone assays are sensitive methods for the differentiation of euthyroid subjects and patients with hyper- and hypothyroidism. In conclusion, the automated thyroid hormone immunoassays on the random-access LIAISON immunoassay analyser proved to be very satisfactory, both from the analytical and the clinical point of view. PMID:10791127
Hubl, W; Meissner, D; Demant, T; Becker, W; Hörmann, R; Bach, M; Mack, M
SummaryThe Swiss Bone Marrow Donor Registry was established in 1988 as a project of Swisstransplant. Up to January 1999, a total of 14,753 unrelated donors have been recruited by the Regional Blood Transfusion Centers of the Swiss Red Cross Blood Transfusion Service. HLA-AB typing of the donors is performed at laboratories of blood transfusion centers or universities; the Laboratoire national
A method of solid-phase fluoroimmunoassay of thyroxine (T4) on polystyrene 96-microtiter plates using coproporphyrin III-labeled antibodies was developed; 0.02 ml of blood serum without preliminary treatment was required. Thimerosal was added to lessen the T4-binding effect of the serum on the results of T4-binding effect of the serum on the results of the immunoassay. A calibration curve was obtained to determine T4 covering the entire physiological range of concentrations (from 3 to 21 micrograms of thyroxine in 100 ml of the serum). A variation coefficient within this range did not exceed 15%. For 14 unknown blood serum samples of patients the coefficient of correlation with the results obtained using a commercial kit for T4 determination (Abbott, USA) was 0.960. The time of the assay was 2-2.5 h. This method is simple and easy for use on a large scale. PMID:3293030
External quality assessment schemes (EQAS) provide an important means of monitoring the quality of the performance of immunoassays in the field. Set up by external bodies and complementing internal quality control procedures, they enable ongoing comparison of individual laboratory results, both with independently established target values and with results of other participating laboratories. Well-designed EQAS assess analytical performance particularly with respect to bias and precision, but also give some indication of the type of errors that most frequently occur in routine practice. EQAS must themselves meet nationally and/or internationally agreed standards so that participants can have confidence in the data generated. Some of the standards currently applied in the UK are described in this chapter, with examples of how these standards can be met also provided. PMID:23996372
In this manuscript, we report on electrochemical biosensors based on various nanoparticles (NPs) as labels for sensitive detection of protein biomarkers. We used silica nanoparticle as a carrier to loading a large amount of electroactive species such as poly(guanine) for sensitive immunoassay of tumor necrosis factor-alpha (TNF-a). We took the advantages of the unique hollow structure and reconstruction properties of apoferritin to prepare Cd3(PO4)2 nanoparticles as labels for sensitive assay of TNF-a. A novel immunochromatographic/electro-chemical biosensor based on quantum dots as labels has also been developed for rapid and sensitive detection of prostate-specific antigen (PSA) in human serum. These biosensors are quite sensitive with the detection limit at pM level and these approaches based on nanoparticle labels offer a new avenue for sensitive detection of protein biomarkers.
There is an increasing need for the development of an ultrasensitive immunoassay for use with fiber optic sensors. These detection systems can be used for such applications as disease diagnosis, detection of chemical and biological warfare agents or drugs of abuse, pollution control, therapeutic monitoring, and explosive detection. This specific program is designed to produce generic chemistries for use with existing fiber optic-based sensors to detect pathogens of particular threat to Army personnel as determined by USAMRIID. The detection system under development involves the attachment of antibodies to an optical fiber at high density. In addition, the immobilization must be achieved in a way which retains the antibody's ability to bind antigen. The functionality of the antibody will be tested through the binding of a labelled antigen. In the future, this assay could incorporate the antibodies developed by the Army for pathogens of particularly military concern.
... FDA's Guidance for Industry: Implementation of an Acceptable Full-Length and Abbreviated Donor History Questionnaires and Accompanying ... More results from www.fda.gov/biologicsbloodvaccines/bloodbloodproducts/approvedproducts
A compact waveguide biosensor that can simultaneously sense multiple analytes has been implemented. The responses to multiple immunoassay complex adlayers with different surface coverage were measured using near-field scanning optical microscopy.
Kevin L. Lear; Guangwei Yuan; Matthew D. Stephens; Xinya He
An immunoassay applicable to the Manual Threshold instrument was developed for the detection of Bacillus anthracis spores. The assay involved two antibodies raised against inactivated spores of B. anthracis Sterne strain 34F2, and they were labelled with ...
The Ca(2+)-regulated photoprotein obelin has been examined as a label for bioluminescence immunoassay of infective agents. The hepatitis B virus (HbsAg) and the bacteria Escherichia coli and Shigella sonnei lipopolysaccharide (LPS) were chosen as model antigens. Chemically synthesized obelin-corresponding antibody conjugates were used in a solid-phase microplate immunoassay. The sensitivities achieved by the assay were 0.25 ng/mL for S. sonnei LPS and 0.375 ng/mL for HbsAg. A novel, filter-based immunoassay to determine bacterial admixtures in the environment was proposed. The NanoCeram filters were effectively applied to 'trap' and pre-concentrate pathogens from samples under study for the purposes of further detection and measurement of the absorbed material by bioluminescence immunoassay. PMID:17286244
Frank, L; Markova, S; Remmel, N; Vysotski, E; Gitelson, I
A simple, sensitive SERS-based immunoassay realized in aqueous solution is demonstrated with a sandwich immune protocol. In such an immunoassay, antibodies-immobilized silica nanoparticles served as the immune substrate while 4MBA-labeled immuno-Au nanoparticles are used as the immune sensors. According to the TEM images, it is clear that the immune gold nanoparticles are embedded onto the surfaces of the silica nanoparticles
C. Y. Song; Z. Y. Wang; J. Yang; R. H. Zhang; H. Wu; Y. P. Cui
In this study enzyme immunoassays are presented for the assessment of platelet adhesion\\/activation and fibrinogen adsorption\\/conformation. The estimation of platelet adhesion and activation was performed with two enzyme immunoassays (EIAs) using monoclonal antibodies directed against CD42b (GP Ib) and CD 62 (GMP 140 or P-Selectin). The applicability of EIA was first demonstrated in microtitre plates coated with fibrinogen. The thrombogenic
Th. Groth; E. J. Campbell; K. Herrmann; B. Seifert
The sensitive and specific detection of analytes such as proteins in biological samples is critical for a variety of applications,\\u000a for example disease diagnosis. In immunoassays a signal in response to the concentration of analyte present is generated by\\u000a use of antibodies labeled with radioisotopes, luminophores, or enzymes. All immunoassays suffer to some extent from the problem\\u000a of the background
Given the progress toward Fund closure, donors ex- pressed support for the initiation of an independent les- sons learned exercise that will be undertaken jointly with the World Bank, in cooperation with the GoI. The objective of the exercise was presented by the Dep- uty Special Representative for the Secretary General (DSRSG) Christine McNab to the Donor Committee. The Lessons
|Most major donors don't need another plaque or formal dinner. Development officers need to be more imaginative and less materialistic in expressing their institution's thanks, personalizing them by tying the gesture in with something distinctive about the institution or the gift. Development office teamwork and care help promote donor
Most major donors don't need another plaque or formal dinner. Development officers need to be more imaginative and less materialistic in expressing their institution's thanks, personalizing them by tying the gesture in with something distinctive about the institution or the gift. Development office teamwork and care help promote donor
Donor conception research supports open-identity donor programmes and disclosure to donor-conceived offspring. This study examines Australian donors, recipients and donor-conceived offsprings views on the importance of different types of biographical information about the donor. Participants (125 recipients, 39 donors (known, identity-release and anonymous), 23 donor-conceived offspring) completed an online or paper self-administered anonymous questionnaire. Individuals rated the importance of 15
Large registries of potential unrelated stem cell donors have been established in order to enable stem cell transplantation for patients without HLA-identical related donors. Donor search is complicated by the fact that the stored HLA information of many registered donors is incomplete. We carried out a project that was aimed to improve chances of patients with ongoing donor searches to find an HLA-matched unrelated donor. For that purpose, we carried out additional donor center-initiated HLA-DRB1 typing of donors who were only typed for the HLA loci A and B so far and were potential matches for patients in need of a stem cell transplant. In total, 8,861 donors were contacted for donor center-initiated HLA-DRB1 typing within 1,089 donor searches. 12 of these donors have donated stem cells so far, 8 thereof for their respective target patients. We conclude that chances of patients with ongoing donor searches to find an HLA-matched unrelated donor can indeed be improved by donor-center initiated typing that is carried out in addition to the standard donor search process. Our results also raise questions regarding the appropriate use of incompletely typed donors within unrelated donor searches.
Schmidt, Alexander H.; Solloch, Ute V.; Baier, Daniel; Grathwohl, Alois; Hofmann, Jan; Pingel, Julia; Stahr, Andrea; Ehninger, Gerhard
Large registries of potential unrelated stem cell donors have been established in order to enable stem cell transplantation for patients without HLA-identical related donors. Donor search is complicated by the fact that the stored HLA information of many registered donors is incomplete. We carried out a project that was aimed to improve chances of patients with ongoing donor searches to find an HLA-matched unrelated donor. For that purpose, we carried out additional donor center-initiated HLA-DRB1 typing of donors who were only typed for the HLA loci A and B so far and were potential matches for patients in need of a stem cell transplant. In total, 8,861 donors were contacted for donor center-initiated HLA-DRB1 typing within 1,089 donor searches. 12 of these donors have donated stem cells so far, 8 thereof for their respective target patients. We conclude that chances of patients with ongoing donor searches to find an HLA-matched unrelated donor can indeed be improved by donor-center initiated typing that is carried out in addition to the standard donor search process. Our results also raise questions regarding the appropriate use of incompletely typed donors within unrelated donor searches. PMID:21625451
Schmidt, Alexander H; Solloch, Ute V; Baier, Daniel; Grathwohl, Alois; Hofmann, Jan; Pingel, Julia; Stahr, Andrea; Ehninger, Gerhard
The identification and characterization of risk factors and their molecular implications in the pathophysiology of human diseases such as cancer is essential for designing efficient diagnostic assays and therapeutic compounds. Estrogenic steroids, under normal physiological conditions, have been shown to play a critical function in several tissues. The response of such a variety of tissues to estrogen stimulation can explain in part its active role in the development and progression of different human diseases, particularly breast cancer. Searching for estrogen-responding cellular factors in parental cells of primary human breast carcinomas obtained from tumour biopsies, two cellular markers, an isoenzyme of putative leucine aminopeptidase (LAPase; EC 220.127.116.11) from parental cells of primary human breast carcinomas obtained from tumour biopsies, and cytosolic NDP-Kinase/Nm23 (EC 18.104.22.168) from HL60 cells were identified. Monoclonal antibodies against each cellular marker have been produced. Determination of the presence of these two markers, either alone or in combination, -can be used to detect breast cancer, and in particular, associated metastatis. Thus, this invention refers to the use of both LAP and NDP-Kinase/Nm23 monoclonal antibodies together in a tandem solid-matrix based immuno-assay for first line confimatory blood-based testing for breast cancer.
Background Toxoplasma gondii (T. gondii) infection in blood donors could represent a risk for transmission in blood recipients. There is scarce information about the epidemiology of T. gondii infection in blood donors in Mexico. Therefore, we sought to determine the prevalence of T. gondii infection and associated socio-demographic and behavioral characteristics in a population of healthy blood donors of Durango City, Mexico. Methods Four hundred and thirty two blood donors in two public blood banks of Durango City, Mexico were examined for T. gondii infection between August to September 2006. Blood donors were tested for anti-T. gondii IgG and IgM antibodies by using enzyme-linked immunoassays (Diagnostic Automation Inc., Calabasas, CA, USA). Socio-demographic and behavioral characteristics from each participant were also obtained. Results Thirty two (7.4%) of 432 blood donors had IgG anti-T. gondii antibodies. Eight (1.9%) of them had also IgM anti-T. gondii antibodies. Multivariate analysis using logic regression showed that T. gondii infection was associated with the presence of cats at home (adjusted OR = 3.81; 95% CI: 1.4510.01). The age group of 4560 years showed a significantly higher frequency of T. gondii infection than the group of 2534 years (p = 0.02). Blood donors without education had a significantly higher frequency of infection (15.8%) than those with 1319 years of education (4.5%) (p = 0.04). Other characteristics of blood donors including male gender, consumption of undercooked meat or blood transfusion did not show an association with infection. Conclusion The prevalence of T. gondii infection in healthy blood donors of Durango City, Mexico is lower than those reported in blood donors of south and central Mexico, and is one of the lowest reported in blood donors worldwide. T. gondii infection in our blood donors was most likely acquired by contact with cats. Prevalence of infection increased with age and decreased with educational level.
Alvarado-Esquivel, Cosme; Mercado-Suarez, Miguel Francisco; Rodriguez-Briones, Alfredo; Fallad-Torres, Laura; Ayala-Ayala, Julio Octavio; Nevarez-Piedra, Luis Jorge; Duran-Morales, Ehecatl; Estrada-Martinez, Sergio; Liesenfeld, Oliver; Marquez-Conde, Jose Angel; Martinez-Garcia, Sergio Arturo
We describe a novel microfluidic immunoassay method based on the diffusion of a small molecule analyte into a parallel-flowing stream containing cognate antibody. This interdiffusion results in a steady-state gradient of antibody binding site occupancy transverse to convective flow. In contrast to the diffusion immunoassay (Hatch et al. Nature Biotechnology,19:461?465 (2001)), this antibody occupancy gradient is interrogated by a sensor surface coated with a functional analog of the analyte. Antibodies with at least one unoccupied binding site may specifically bind to this functionalized surface, leading to a quantifiable change in surface coverage by the antibody. SPR imaging is used to probe the spatial distribution of antibody binding to the surface and, therefore, the outcome of the assay. We show that the pattern of antibody binding to the SPR sensing surface correlates with the concentration of a model analyte (phenytoin) in the sample stream. Using an inexpensive disposable microfluidic device, we demonstrate assays for phenytoin ranging in concentration from 75 to 1000 nM in phosphate buffer. At a total volumetric flow rate of 90 nL/sec, the assays are complete within 10 minutes. Inclusion of an additional flow stream on the side of the antibody stream opposite to that of the sample enables simultaneous calibration of the assay. This assay method is suitable for rapid quantitative detection of low-molecular weight analytes for point-of-care diagnostic instrumentation.
Background A decrease in the prevalence of hepatitis C virus antibody (anti-HCV) has been reported among voluntary blood donors in some regions of China. However, the prevalence of HCV among volunteer blood donors in other regions of China has not been reported. The aim of this study was to investigate the seroprevalence of HCV among 559,890 first-time volunteer blood donors recruited during 2004 through 2007 at the Guangzhou Blood Center, China. Study Design and Methods Anti-HCV was detected using two different third-generation enzyme immunoassay kits. HCV RNA was detected using reverse transcriptionpolymerase chain reaction (RT-PCR) targeting the 5?-untranslated region of HCV. Results Among 559,890 donors, 1877 (0.335%) were positive for anti-HCV. The anti-HCV+ rate was significantly higher in males than females (0.37% vs. 0.28%; p < 0.001) and significantly lower among donors living in Guangdong Province than donors who had migrated from other locations (0.30% vs. 0.40%; p < 0.001). Among the 1877 anti-HCV+ donors, 450 were randomly selected for HCV nucleic acid amplification by RT-PCR. Of these, 270 (60%) were HCV RNA+ and 180 (40%) were HCV RNA. Conclusions Many donors from outside Guangdong Province were migrant laborers from other areas in China, suggesting that there is regional heterogenicity in HCV prevalence within China. The overall anti-HCV+ rate reported here is among the lowest reported among blood donors in China reflecting the effect of the current recruitment of exclusively volunteer donors.
Immunoassays are utilized for a wide variety of clinical and biomedical research applications. In typical immunoassays, analytes are captured, labeled, and quantified on a single surface (e.g., the bottom of a well plate). In order to minimize the background, this type of assay must be washed multiple times between each of these steps to ensure residual reagents (e.g., unbound labeling antibody) are removed from the system. In this manuscript, the immunoassay is fundamentally reconfigured, such that each reagent is confined to its own well and no wash steps are required. Using immiscible filtration assisted by surface tension (IFAST), a technique developed for nucleic acid and whole cell purifications, immunoassays can be drastically simplified such that all reagent manipulation is performed at the start of the assay (i.e., no pipetting steps are necessary during the assay). Analytes are bound to paramagnetic particles via antibodies and drawn through oil barriers between four isolated compartments: (1) sample well, (2) primary antibody labeling well, (3) secondary antibody labeling well, and (4) readout buffer well. Using this technique, we have demonstrated repeatable detection of as little as 188 fg of protein. IFAST immunoassay functionality is demonstrated by detecting a well accepted prostate cancer biomarker, prostate specific antigen (PSA). Assay performance was assessed by measuring known concentrations of recombinant PSA protein. The assay was then used to measure PSA concentrations in conditioned media and human plasma samples. PMID:22632629
Berry, Scott M; Maccoux, Lindsey J; Beebe, David J
All right hepatic lobe (RHL) donors in our program are asked to participate in a longitudinal quality-of-life study that begins at their evaluation and continues throughout the first postdonation year. Here we report the characteristics of donor candidates who completed the donation process despite ambivalence. In all, 183 RHL candidates consented, and 133 became donors. Ambivalent donors (ADs; n = 45) identified themselves through verbal statements or written comments, or they were identified by staff during the evaluation. ADs were predominantly male (73.3%), were older than unambivalent donors (UADs; >35 years: 76% of ADs versus 53% of UADs, P = 0.008), and were well educated (college graduate: 60% of ADs versus 17% of UADs, P = 0.01). Brother-to-brother and son-to-father combinations were most common among ADs. Alcohol (22% versus 11%, P = 0.04) and hepatitis C virus (51% versus 27%, P = 0.008) were more common as disease etiologies for recipients with ADs versus recipients with UADs. More ADs than UADs considered themselves to be religious (68.9% versus 43.2%, P = 0.007). Ambivalence about RHL donation was present in 33.8% of the candidates who completed the donation process. These results suggest that ambivalence should not be the sole reason for disqualifying a potential donor who otherwise satisfies program requirements. PMID:21604356
Simpson, Mary Ann; Kendrick, Julia; Verbesey, Jennifer E; Morin, Denise S; Dew, Mary Amanda; Trabucco, Agnes; Pomposelli, James J; Pomfret, Elizabeth A
|This descriptive and causal comparative study sought to identify motivations for alumni donor acquisition and retention in Christian institutions of higher learning. To meet this objective, motivations for alumni donors, lapsed donors, and non-donors were analyzed and compared. Data was collected through an electronic survey of a stratified
Bayer HealthCare LLC, Diagnostics Division, has developed several new assays on the ADVIA Centaur immunoassay system for the detection of markers of hepatitis B virus infection in human serum and plasma. This panel includes assays for: hepatitis B surface antigen (HBsAg), a confirmatory test method for HBsAg, antibodies to hepatitis B surface antigen (anti-HBs), IgM and IgG antibodies to hepatitis B core antigen (anti-HBc Total) and IgM antibodies to hepatitis B core antigen (anti-HBc IgM). These assays employ magnetic particle separation technology with direct chemiluminescence for optimal assay performance. All of the assays are fully automated, require sample volumes ranging from 15 microl to 100 microl (with the exception of the ADVIA Centaur HBsAg Confirmatory Assay, which requires 2 x 100 microl), and have throughputs of up to 240 tests per hour. The five ADVIA Centaur HBV assays were tested in extensive performance evaluations conducted at two sites in Europe. The performance evaluations, which included samples from HBV-infected individuals, blood donors, hospitalized/clinical patients, and HBV vaccinees (for Anti-HBs evaluation), generated performance data in support of obtaining the Communautés Européennes (CE) mark for European market distribution. The HBV performance evaluations resulted in an overall diagnostic specificity > 99%, i.e. 99.94% for the ADVIA Centaur HBsAg Assay, 100% for the ADVIA Centaur Anti-HBs Assay, 100% for the ADVIA Centaur HBc IgM Assay and 99.94% for the ADVIA Centaur HBc Total Assay. All of the ADVIA Centaur assays showed a very good diagnostic sensitivity on these populations with 100% for the ADVIA Centaur HBsAg Assay, 99.0% for the ADVIA Centaur Anti-HBs Assay, 98.53% for the ADVIA Centaur HBc IgM Assay and 100% for the ADVIA Centaur HBc Total Assay. The ADVIA Centaur HBsAg Confirmatory Test confirmed 100% of the positive HBsAg samples. Testing of interfering substances and potential cross-reacting samples for all ADVIA Centaur HBV assays resulted in no change in interpretation of the results. Assay performance was further evaluated using HBV seroconversion panels with comparable or better results when compared to the comparison assays. The performance evaluation data demonstrate that the ADVIA Centaur HBV assays are specific and sensitive automated immunoassays for detection of antigens and antibodies to hepatitis B virus with performance that is comparable to those of currently marketed assays. Additionally, these assays have the advantage of being available on the ADVIA Centaur immunoassay system, which provides for the flexibility of high throughput and full automation. PMID:15000222
van Helden, Josef; Denoyel, Gérard; Karwowska, Sylwia; Reamer, Randy; Schmalz, John; Wright, Ted; Preisel-Simmons, Barbara
This plan provides a detailed design and description of the demonstration and evaluation program for the Westinghouse Bio-Analytic Systems immunoassay technologies specific for the analysis of pentachlorophenol. he immunoassays measure parts per billion concentrations of pentachl...
Enzyme immunoassays with optical detection are amongst the most widely used bioanalytical tools. We defined seven parameters for the quality assessment of immunoassays that were addressed in a systematic study of direct and indirect immunoassays, using the enzymes horseradish peroxidase (HRP) and alkaline phosphatase (AP), the chromogenic substrates 3,3',5,5'-tetramethylbenzidine (TMB) and para-nitrophenyl phosphate, and the fluorescent substrates 3-(4-hydroxyphenyl)propionic acid and 4-methylumbelliferyl phosphate. The same monoclonal antibody against caffeine was used throughout the study. The four quality parameters regarding the standard curve were the test midpoint (sensitivity), the measurement range, the relative dynamic range of the signal, and the goodness of fit of the adjusted four-parameter logistic function. All HRP immunoassays showed a higher sensitivity compared to the AP assays. On the basis of all four criteria, it was established that the direct assay format is superior to the indirect format, the immunoassay using HRP TMB fulfilling all requirements best. In a second step, caffeine concentrations in 24 beverage and cosmetics samples were determined and three more quality parameters were assessed with this application. The direct HRP TMB assay showed one of the best intra- and inter-plate precisions and the best accuracy, defined by the correlation of results with those from the chosen reference method liquid chromatography tandem mass spectrometry (LC-MS/MS). Considering all criteria, HRP TMB seems to be the enzyme substrate system of choice preferably used in the direct assay format. PMID:23224576
Pre-donation kidney volume and function may be crucial factors in determining graft outcomes in kidney transplant recipients. We measured living donor kidney volumes by 3D helical computed tomography scanning and glomerular filtration rate (GFR) by (125)I-iothalamate clearances in 119 donors, and correlated these values with graft function and incidence of acute rejection at 2 years post-transplantation. Kidney volume strongly correlated with GFR (Pearson r= 0.71, p < 0.001). Body size and male gender were independent correlates of larger kidney volumes, and body size and age were predictors of kidney function. The effects of transplanted kidney volume on graft outcome were studied in 104 donor-recipient pairs. A transplanted kidney volume greater than 120 cc/1.73 m(2) was independently associated with better estimated GFR at 2 years post-transplant when compared to recipients of lower transplanted kidney volumes (64 +/- 19 vs. 48 +/- 14 mL/min/1.73 m(2), p < 0.001). Moreover, recipients of lower volumes had a higher incidence of acute cellular rejection (16% vs. 3.7%, p = 0.046). In conclusion, kidney volume strongly correlates with function in living kidney donors and is an independent determinant of post-transplant graft outcome. The findings suggest that (1) transplantation of larger kidneys confers an outcome advantage and (2) larger kidneys should be preferred when selecting from otherwise similar living donors. PMID:16468974
Poggio, E D; Hila, S; Stephany, B; Fatica, R; Krishnamurthi, V; del Bosque, C; Goldfarb, D; Herts, B; Dennis, V W; Heeger, P S; Braun, W
Altruistic donors face common good problem which calls for cooperation and policy integration. On the other hand, the more united and responsible donors act towards the poor in the country that receives aid, the less domestic support does the poor get. I study these two countervailing effects of donor cooperation in different settings. Cooperation is always beneficial if donors can
This descriptive study surveyed current, lapsed, and major gift donors to explore the impact of college communications on donors' decisions to contribute to the college, the likelihood of donor financial support for various college projects, and the philanthropic motivation profiles of the donors of a midsized, multicampus community college in Virginia. Findings suggest both the impact of college communications and
Template matching method is presented to identify the peaks from the scanned signals of lateral flow immunoassay strips. The template is composed of two pulses separated by the distance of the control and the target ligand line in the assay, and is convolved with the scanned signal to deliver the maximum at the center of the two peaks. The peak regions were identified with the predefined distances from the center. Glycosylated haemoglobin immunoassay strips and fluorescent strip readers from Boditechmed Inc. were tested to estimate the lot and reader variations of the concentration measurands. The results showed the robustness of the propose method.
Kim, Jongwon; Kim, Jong Dae; Nahm, Kie Bong; Choi, Eui Yul; Lee, Geumyoung
All analytical techniques employed in the biological sciences rely on recognition of the shape and structure of molecules of the substance of interest (the analyte). Such molecular recognition and sensing usually relies on the use other molecules possessing a complementary structure, implying a specific lock and key relationship between the two. Antibodies comprise a class of recognition molecules evolved by nature for the purpose of bodily defence, and are clearly of particular utility in this context. However techniques of increasing sophistication (including the techniques of molecular biology) are currently being developed which enable the artificial construction of antibody-like molecules possessing improved molecular recognition properties which can be harnessed for microanalytical purposes. Oligonucleotide probes likewise exhibit the property of binding to complementary nucleotide sequences, and the techniques of, for example, in situ hybridisation therefore share many features with immunoassay techniques. Microanalytical techniques relying on binding reactions between substances possessing complementary lock and key molecular structures are unlikely to be superseded within the foreseeable future, only the labels used to monitor such reactions, and the means of production of "recognition molecules", being subject to further development. Such techniques already enter into all areas of life, including medicine, agriculture, etc, and are likely to increase further in importance with increasing concern regarding chemically complex contaminants in food, the environment, etc. Developments in this field are clearly directed to slightly differing objectives as indicated in this presentation. These include methodological simplification (making the techniques cheaper and more widely available), improvements in sensitivity (to enable the detection and measurement of substances beyond the reach of current methods) and the construction of transducer-based sensor methods (permitting, inter alia, the monitoring of changing analyte concentrations). However the combination of the "ultrasensitivity" of current single analyte assay methods with the ability simultaneously to determine multiple analytes in the same sample represents, in my view, the next major methodological challenge in this field, and--if successfully addressed--will constitute a quantum advance on present analytical methods. Indeed the development of miniaturised multianalyte binding assay techniques may ultimately comes to be seen as analagous to, for example, the introduction of the word processor, and other similar major technological advances of the past decade. PMID:9234310
Medical advances in bone marrow transplantation techniques and immunosuppressive medications have dramatically increased the number of such transplants performed each year, and consequently, the demand for bone marrow from unrelated donors. Although physiological aspects of bone marrow donation have been thoroughly investigated, very few studies have examined psychosocial factors that may impact individuals' donation decisions and outcomes. To examine one
Galen E. Switzer; Mary Amanda Dew; Victoria A. Butterworth; Roberta G. Simmons; Mindy Schimmel
Aim: To investigate the clinical correlates of a novel lateral flow immunoassay with bleeding on probing, oral hygiene and periodontal pocket depth. This report offers a simple, rapid, and highly sensitive tool that addresses two important issues dear to the heart of periodontists: 1) detecting active periodontitis, and 2) predicting chronic periodontitis. Materials and methods: Seventy-six of eighty-six men requiring seminal fluid analysis as part of a separate study were serially recruited into the study. After basic dental and periodontal examination under natural light and with the use of the Community Periodontal Index of Treatment Needs (CPITN) probe, debris and calculus indices were recorded per participant. Participants were subsequently grouped into 'Good', 'Fair' and 'Poor' oral hygiene based on the simplified oral hygiene index of Greene and Vermillion. Bleeding on probing was assessed with the ball-ended tip of the CPITN probe and periodontitis was assessed with pocket probing as well as a lateral flow of Neutrophil collagenase-2 immunoassay which measures levels of Matrixmetalloproteinase-8. Results: Neutrophil collagenase-2 immunoassay was 96% sensitive for poor oral hygiene, 95% sensitive for chronic periodontitis regarded as at least two sites with periodontal pockets and 82.6% sensitive for at least two sites with bleeding on probing.(BOP). Conclusion: Neutrophil collagenase-2 immunoassay had a high sensitivity for at least two sites with bleeding on probing and two sites periodontal pockets but lower relationship for single site pocket and bleeding on probing. PMID:23600996
Nwhator, S O; Ayanbadejo, P O; Umeizudike, K A; Opeodu, O I; Agbelusi, G A; Olamijulo, J A; Arowojolu, M O; Sorsa, T; Babajide, B S; Opedun, D O
An evaluation of five commercial software systems used for immunoassay data analysis revealed numerous deficiencies. Often, the utility of statistical output was compromised by poor documentation. Several data sets were run through each system using a four-parameter calibration f...
A portable, small footprint, light, general purpose analyzer (processor) to control the flow in immunoassay cassettes and to facilitate the detection of test results is described. The durable analyzer accepts disposable cassettes that contain pouches and reaction chambers for various unit operations such as hydration of dry reagents, stirring, and incubation. The analyzer includes individually controlled, linear actuators to compress
Xianbo Qiu; Changchun Liu; Michael G. Mauk; Robert W. Hart; Dafeng Chen; Jing Qiu; Terry Kientz; Jonathan Fiene; Haim H. Bau
Template matching method is presented to identify the peaks from the scanned signals of lateral flow immunoassay strips. The template is composed of two pulses separated by the distance of the control and the target ligand line in the assay, and is convolved with the scanned signal to deliver the maximum at the center of the two peaks. The peak
Jongwon Kim; Jong Dae Kim; Kie Bong Nahm; Eui Yul Choi; Geumyoung Lee
We have developed a liquid-phase immunoassay technique using Brownian relaxation of magnetic markers. In this method, biological targets are fixed on the surface of large polymer beads whose size is typically a few . When the markers are bound to the targets, their Brownian relaxation time is dominated by that of the polymer bead, becoming much longer than that of
Chlamydia trachomatis has been shown to be a major cause of sexually transmitted diseases in the United States. An enzyme immunoassay (Abbot Laboratories) has been developed that detects chlamydial antigen directly in the urogenital specimens of patients. We have evaluated specimens from 1,074 patients belonging to one of three risk groups. Three swabs were collected from each patient--one each for Neisseria gonorrhoeae, chlamydia cell culture, and enzyme immunoassay. When compared with cell culture, the sensitivity and specificity of the enzyme immunoassay for symptomatic males and females attending a sexually transmitted disease clinic was 82% and 100%, and 91.3% and 95.0%, respectively. A moderate risk group, consisting of female patients seen at either urology or gynecology clinics for genitourinary symptoms was also evaluated. The sensitivity and specificity of the test on this group was 96% and 96.7%. A population of females at low risk were also screened for chlamydial infection. In this group, the sensitivity and specificity of the enzyme immunoassay was 89.3% and 93.2%, respectively. This rapid test is a highly specific and sensitive procedure for the detection of chlamydial antigen in genital specimens from high risk female patients as well as symptomatic males. PMID:3530626
Ryan, R W; Kwasnik, I; Steingrimsson, O; Gudmundsson, J; Thorarinsson, H; Tilton, R C
A simple, rapid, and sensitive bioelectrochemical immunoassay method based on magnetic beads (MBs) has been developed to detect polycyclic aromatic hydrocarbons (PAHs). The principle of this bioassay is based on a direct competitive enzyme-linked immunosorbent assay using PAH-antibody-coated MBs and horseradish peroxidase (HRP)-labeled PAH (HRP-PAH). A magnetic process platform was used to mix and shake the samples during the immunoreactions and to separate free and unbound reagents after the liquid-phase competitive immunoreaction among PAH-antibody-coated MBs, PAH analyte, and HRP-PAH. After a complete immunoassay, the HRP tracers attached to MBs were transferred to a substrate solution containing 3, 3´, 5, 5´- tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) for electrochemical detection. The voltammetric characteristics of the substrate were investigated, and the reduction peak current of TMB was used to quantify the concentration of PAH. The different parameters, including the amount of HRP-PAH conjugates, the enzyme catalytic reaction time, and the pH of the supporting electrolyte that governs the analytical performance of the immunoassay have been studied in detail and optimized. The detection limit of 50 pg mL-1 was obtained under optimum experimental conditions. The performance of this bioelectrochemical magnetic immunoassay was successfully evaluated with tap water spiked with PAHs, indicating that this convenient and sensitive technique offers great promise for decentralized environmental applications.
Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe
Highly sensitive and specific gold nanoparticle based dipstick immunoassay using protoplasmic antigen of Mycobacterium avium subspecies paratuberculosis (MAP) for diagnosis of paratuberculosis was introduced. In this method the colloidal gold nanoparticles (GNPs) were coated with MAP protoplasmic antigen using alkanethiols derivatives and anti-MAP rabbit antibodies. These antigen coated GNPs acts as a detector reagent in this assay. The antibody (test
Immunoassay techniques yield estimates of concentrations of analytes based on comparison to known concentrations of a reference solution. The use of the nonlinear logistic model makes the error estimates and confidence levels approximate. When the goal of such a study is estimation of several unknowns, methods in common usage do not account for simultaneous inference, i.e. the repeated use of
A simple test of parallelism in immunoassays is proposed. Various amounts of a biological material are assayed and the concentrations are computed on the basis of a standard curve. All concentration estimates are equal and independent of the amount (volume) assayed, if the dose-response relationships of both the standard and the unknown are intrinsically parallel. This type of parallelism test
A superconducting quantum interference device (SQUID) for application to biological immunoassays has been designed. In this application, the magnetic field from a magnetic marker made of magnetic nanoparticles is detected with the SQUID. It is shown that the conventional design of the SQUID that was developed for the case of uniform magnetic field cannot be used in this application, since
An improvement in enzyme linked immunoassays is disclosed wherein the enzyme is in the form of a water soluble polymer saccharide conjugate which is stable in hostile environments. The conjugate comprises the enzyme which is linked to the polymer at multiple points through saccharide linker groups.
Callstrom, Matthew R. (Columbus, OH); Bednarski, Mark D. (Berkeley, CA); Gruber, Patrick R. (St. Paul, MN)
An improvement in enzyme linked immunoassays is disclosed wherein the enzyme is in the form of a water soluble polymer saccharide conjugate which is stable in hostile environments. The conjugate comprises the enzyme which is linked to the polymer at multiple points through saccharide linker groups. 19 figs.
Different proteins such as antibodies, antigens, and enzymes were immobilized within the 100 × 100 × 20-?m gel pads of protein microchips. A modified polyacrylamide gel has been developed to accommodate proteins of a size up to 400,000 daltons. Electrophoresis in the microchip reaction chamber speeded up antigenantibody interactions within the gel. Protein microchips were used in immunoassays for detection
Pavel Arenkov; Alexander Kukhtin; Anne Gemmell; Sergey Voloshchuk; Valentina Chupeeva; Andrei Mirzabekov
Since currently used assays of amphotericin B (AMB) lack sensitivity or are not easily adaptable in all laboratories, we have developed an enzyme immunoassay for AMB in biological fluids and tissues. Antibodies to AMB were raised in rabbits after administration of an AMB-bovine serum albumin conjugate. The enzy- matic tracer was obtained by coupling AMB via its amino group to
SOPHIE MACHARD; FREDERIC THEODORO; HENRI BENECH; JEAN-MARC GROGNET; ERIC EZAN
The development of a solid-phase microtiter enzyme immunoassay (EIA) for detection of Norwalk virus antigen in stool samples is described. The EIA was compared with a previously developed radioimmunoassay (RIA) for detection of Norwalk virus antigen in stools obtained from 30 vol...
The excited state intra molecular charge transfer (ICT) property of fluorophores has been extensively used for the design of fluorescent chemosensors. Herein, we report the synthesis and properties of three donor?-acceptor?-donor (D?-A?-D) based molecular probes BP, BT and BA. Two heteroaromatic rings, pyrrole (BP), and thiophene (BT) and a non-heteroaromatic ring N-alkoxy aniline (BA) were selected as donor moieties which were linked to a bipyridine binding site through a vinylic linkage. The heteroaromatic systems BP and BT perform selective and ratiometric emission signalling for zinc ions whereas the non-heteroaromatic probe BA does not. The advantages of the D?-A?-D design strategy in the design of ICT based probes for the selective fluorescent ratiometric signalling of zinc ions in biological media is discussed. Further, the use of BP, BT and BA for imaging Zn(2+) ions from MCF-7 cell lines is demonstrated. PMID:22875072
The Exxon donor solvent (EDS) coal liquefaction system is a direct liquefaction procedure. Coal is chemically reacted and dissolved in a recycle solvent that is hydrogenated between passes to the liquefaction reactor. More than 2.6 barrels of a synthetic crude boiling below 1000 F are produced per ton of dry, high volatile coal feed. Other ranks of coal can be
A novel chemiluminescence resonance energy transfer (CRET) system for competitive immunoassay of biomolecules was developed by using novel amorphous carbon nanoparticles (CNPs) prepared from candle soot as energy acceptors. The CNPs were firstly prepared to bind with the antigen (Ag) for obtaining the nanocomposite CNP-Ag, and this obtained CNP-Ag was then reacted with the horseradish peroxidase-labeled antibody (HRP-Ab) to assemble the CRET system. The luminol catalyzed by HRP serving as the energy donor for CNPs triggered the CRET phenomenon between luminol and CNPs, which led to the chemiluminescence signal decrease. Due to the competitive immunoreaction of the target antigen and the CNP-Ag, a part of the CNP-Ag was replaced from the HRP-Ab, and then resulted in a weaker interaction between luminol and CNPs. Thus the competitive immunoreaction led to a higher chemiluminescence emission. This CNP-based CRET system was successfully applied to detect the human IgG as a model analyte, and a linear range of 10-200 ng mL(-1) and a detection limit of 1.9 ng mL(-1) (S/N = 3) were obtained. The results for real sample analysis demonstrated its application potential in some important areas such as clinical diagnosis. PMID:23979821
... for Industry: Adequate and Appropriate Donor Screening Tests for Hepatitis B; Hepatitis B Surface Antigen (HBsAg) Assays Used to Test Donors of ... More results from www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/guidances
... Donor Information System (DIS) 3.2. Applicant: BioLife Plasma Services, LP. 510(k) number: BK060017. Product: Donor Information System (DIS) 3.2 ... More results from www.fda.gov/biologicsbloodvaccines/bloodbloodproducts/approvedproducts
... Haemonetics Software Solution Division Edmonton, AB, Canada. ... a problem related to donor visit records in Donor Management (DMS) System. ... More results from www.fda.gov/biologicsbloodvaccines/safetyavailability/recalls
... be an Organ Donor? Questions and Answers about Organ Donation Nasimul Ahsan Steven Alexander Roy Bloom Carl Cardella ... be an Organ Donor? Questions and Answers about Organ Donation 1. Why ask healthy people to be organ ...
Text Version... Collection facilities using these screening materials should be aware that these materials were tested in English-speaking donor and non-donor ... More results from www.fda.gov/downloads/biologicsbloodvaccines/bloodbloodproducts
... all donors (universal testing); (2) reentry testing of all at-risk donors with a history of potential exposure to malaria anywhere in the world; and (3 ... More results from www.fda.gov/biologicsbloodvaccines/guidancecomplianceregulatoryinformation/guidances
Informed consent of the patient to medical treatment is an essential prerequisite for any invasive medical procedure. However in emergency cases, when the patient is unable to sign a consent form due to unconsciousness or to psychotic state, than the primary medical consideration shall take place. In such a case, in order to save life or even prevent a major medical hazard to the patient, doctors are allowed, in certain cases and in accordance with well accepted medical practice, to perform invasive procedures, major surgery or risky pharmacological treatment, without the explicit consent of the patient. All the above refers to the cases when avoidance of such non-consented treatment may harm severely the health and wellbeing of the patient and there is no doubt that such treatment is for the ultimate benefit of the patient. The question, however, shall arise when such a medical procedure is not necessarily for the benefit of the patient, but rather for the benefit of somebody else. Such is the case in the transplantation area and the question of living donor-donee relationship. This paper shall analyze the legal situation in cases of non competent donors whose consent cannot be considered legal consent given in full understanding and out of free will. It will also compare three legal systems, the Israeli, the American and the traditional Jewish law, with regard to the different approaches to this human problem, where the autonomy of the donor may be sacrificed for the purpose of saving life of another person. PMID:19202861
Objective: To report our experience with genetic screening of oocyte donor candidates and to determine the frequency with which significant genetic issues are identified.Design: Prospective genetic screening of oocyte donor candidates.Setting: University hospital oocyte donation program.Patient(s): Women presenting consecutively as volunteer oocyte donors.Intervention(s): Genetic screening was performed by pedigree analysis and laboratory studies.Main Outcome Measure(s): Inclusion in the oocyte donor
Robert Wallerstein; Valerie Jansen; Jamie A. Grifo; Alan S. Berkeley; Nicole Noyes; Jennifer Licker; Frederick Licciardi
Liver cirrhosis and hepatocellular carcinoma related to chronic hepatitis C virus (HCV) infection are currently the most common indications for liver transplantation. The number of living donor liver transplantation (LDLT) procedures has increased given the shortage of donor organs from deceased donors. However, recurrence of HCV infection is universal and affects graft survival. This mini-review compared the outcomes for HCV-positive recipients after LDLT with those after deceased donor liver transplantation. PMID:23052749
After characterizing digoxin immunogens and antibodies, we investigated the assay performances of enzyme immunoassay (EIA), biotinstreptavidin mediated enzyme immunoassay (B-Av EIA), and immunostrip test and compared the effectiveness of these tests for detecting the presence of digoxin and its analogues. The clinical use of digoxin is very complicated due to its narrow therapeutic range. Thus, the development of a rapid
In the past half-century, solid-organ transplantation has become standard treat- ment for a variety of diseases in children and adults. The major limitation for all transplantation is the availability of donors, and the gap between demand and supply continues to grow despite the increase in living donors. Although rare, children do serve as living donors, and these donations raise serious
Successful organ transplantation offers patients with end stage organ failure the chance of a normal life. The recognition of brain death allowed the use of beating heart donors and this has enabled multiple organ procurement from a single donor. Suitable patients with severe brain injury resulting in brain death, who may be potential organ donors, are to be found on
The paper builds on recent empirical evidence on the importance of strategic donor behaviour in aid allocation in order to develop a theoretical model where donor pressure on a recipient for influencing the aid disbursement of a multilateral institution is endogenously determined. Our game-theoretic, multi-agent model with one aid recipient, two bilateral donors and one multilateral institution illustrates the advantage
Purpose: Abnormal hormone levels following brain death result in diffuse metabolic derangement that can lead to hemodynamic instability and deterioration of organ function. We investigated whether methylprednisolone (MP) or the combination of MP and thyroxine (T4) used in routine donor management improves hemodynamic stability.Methods: Procurement records of 133 consecutive donors with successful organ recovery were reviewed. Donors under age 10
A. B. Van Bakel; S. Pitzer; P. Drake; N. A. Kay; R. Sade
The Exxon Donor Solvent (EDS) coal liquefaction system is a direct liquefaction procedure being developed by the Exxon Corporation. Coal is chemically reacted and dissolved in a recycle solvent that is hydrogenated between passes to the liquefaction reactor. More than 2.6 barrels (0.41 m3) of a synthetic crude boiling below 1000 degrees F (538 degrees C) are produced per ton
Authors of recent reports in the medical literature indicate that allograft-associated infection primarily is attributable to violations of proper tissue processing procedures, and illustrate the need for effective quality assurance systems to avoid transplantation of potentially infectious tissue. I describe the experience of the members of the Musculoskeletal Transplant Foundation with the selection, the processing, and the safety of bone and tissue donors for allograft implantation. In 2002, the Musculoskeletal Transplant Foundation screened 10,497 potential donors, but only 4431 (42%) met stringent criteria for recovery. After recovery, another 10% of the donors were rejected, usually because of positive infectious disease tests (45%) or an autopsy finding (31%) that rendered the tissues unsuitable for transplantation. Procedures used by the Musculoskeletal Transplant Foundation for ensuring safety of the tissue and for investigating reports of putative infection are described. The Musculoskeletal Transplant Foundation has had no confirmed cases of allograft-associated infection in over 2 million units transplanted during the past 15 years. PMID:15930916
In this paper, we describe the design and fabrication process of a polydimethylsiloxane (PDMS) microchip for on-chip multiplex immunoassay application. The microchip consists of a PDMS microfluidic channel layer and a micro pneumatic valve control layer. By selectively pressurizing the pneumatic microvalves, immuno reagents were controlled to flow and react in certain fluidic channel sites. Cross contamination was prevented by tightly closed valves. Our design was proposed to utilize PDMS micro channel surface as the solid phase immunoassay substrate and simultaneously detect four targets antigens on chip. Experiment result shows that 20psi valve pressure is sufficient to tightly close a 200µm wide micro channel with flow rate up to 20µl/min.
A superconducting quantum interference device (SQUID) for application to biological immunoassays has been designed. In this application, the magnetic field from a magnetic marker made of magnetic nanoparticles is detected with the SQUID. It is shown that the conventional design of the SQUID that was developed for the case of uniform magnetic field cannot be used in this application, since the spatial variation of the magnetic field from the marker is large. Therefore, a numerical simulation method is developed for obtaining a signal flux detected with the SQUID when the magnetic field changes spatially. It is shown that the signal flux strongly depends on the geometrical parameters of the measurement system, such as the size of the pickup coil, size of the sample and the distance between the sample and the SQUID. The dependence of the signal flux on these geometrical parameters is quantitatively clarified, and the optimum design of the SQUID for the application to magnetic immunoassays is discussed.
Labelled immunoassay by surface enhanced Raman scattering (SERS) has great research and application value. It combines SERS which has the high sensitivity and high selectivity with specific adsorption in immunology. The present paper mainly studies the regeneration about SERS labelled immunoassay, striving to develop the recycling value of it. The authors used glycine-HCl eluent for the sandwich structure including solid matrix antibody, antigen and labelled immuno-gold colloids, then the authors had got expected result. The complex of antibody and antigen would be separated by changing the pH scale. It could elute the most antigen and the labelled immuno-gold colloids. Also the authors could assemble it again and distinguish the characteristic SERS spectrum of the reporter molecules. Under this condition, we researched the stability and reusing of this technology. The authors found that it has better stability and it retained activity after 10 recycles of applications. PMID:20827970
The accuracy, precision, and potential clinical utility of a new whole blood, noninstrumented immunochromatographic assay (AccuLevel) for carbamazepine (CBZ) was evaluated in a multicenter trial including 100 pediatric and 205 adult patients. The AccuLevel assay, a fluorescence polarization immunoassay (FPIA), and high-performance liquid chromatography (HPLC) were used to determine CBZ concentration in samples from 111 female and 194 male patients aged 2-72 years (median 25 years). Mean +/- SD plasma CBZ concentrations in all patients were 7.4 +/- 3.0 micrograms/ml with the AccuLevel assay and 7.5 +/- 2.9 micrograms/ml with FPIA. In 204 patients, the mean concentration determined by the HPLC assay was 7.7 +/- 3.0 micrograms/ml, whereas concentrations determined by the AccuLevel and FPIA assays were 8.0 +/- 3.1 and 8.1 +/- 3.1 micrograms/ml, respectively. Concentrations determined by the AccuLevel and FPIA assays were significantly higher than those quantified by HPLC (p less than 0.05), but not different from each other. In addition, the AccuLevel assay was highly correlated with FPIA (r = 0.97) and HPLC (r = 0.98). Coefficients of variation for the AccuLevel assay at 8 micrograms/ml ranged from 6.8 to 7.5% for the three institutions. We conclude that the AccuLevel assay is a simple, reliable method for determining CBZ concentration in a small volume of whole blood and is an acceptable alternative for assessment of CBZ therapy and individualization of CBZ dosage in the physician's office or emergency room. PMID:2369881
Cochran, E B; Massey, K L; Phelps, S J; Cramer, J A; Toftness, B R; Denio, L S; Drake, M E
An indirect competitive enzyme immunoassay using rabbit antisera could detect citrinin in buffer solutions at 1 to 13 ng/ml (0.05 to 0.65 ng per assay). Cross-reactivity with austdiol, alternariol, ochratoxin A, and deoxynivalenol was < 0.1% relative to citrinin. Recovery of citrinin added to wheat flour at 200 to 2,000 ng/g was 89 to 104%, with a coefficient of variation of 6.9 to 13%.
A dipstick enzyme immunoassay (ELISA) has been standardized for the detection of rinderpest antibodies. One hundred and thirty bovine serum samples were analysed by the dipstick ELISA method and the results compared with the conventional plate ELISA method. The sensitivity was found to be similar in both methods. The dipstick ELISA does not require expensive micro-plates and an ELISA reader, and is recommended for use in field laboratories where the qualitative detection of rinderpest antibodies is required. PMID:8273283
Two types of immunoassays were employed to determine ricin toxin through the substitute of A chain sub-unit in water. Protocol for detecting ricin by commercial enzyme-linked immunosorbent assay (ELISA) kits was established and evaluated. Final results were obtained by this assay in six hours and the detection limit was found to be less than 3 ng mL based on ricin
In enzyme-linked immunosorbent assay (ELISA), as well as in many other kinds of immunoassay, a log-logistic or similar-shaped calibration curve is fit using standards at a series of known levels and then used to transform the measured values for the unknowns into estimated concentrations. The choice of the number of standards, the concentration of the standards, and the number of
A 2-D optical scanner was developed for the imaging and quantification of up-converting phosphor (UCP) labels in immunoassays. With resolution better than 500 mum, a scan rate of 0.4 mm\\/s, and a 1-2% coefficient of variation for repeatability, this scanner achieved a detection limit of fewer than 100 UCP particles in an 8.8 times 104 mum2 area and a dynamic
Janice J. Li; Amy L. Ouellette; Laurent Giovangrandi; David E. Cooper; Antonio J. Ricco; Gregory T. A. Kovacs
Desirable characteristics of enzyme-antibody conjugates for use in enzyme immunoassay are labelling uniformity, permanent availability and stability. The use of monoclonal antibodies (MCABS) for preparation of enzyme conjugates, in place of poly-clonal antibodies, ensures labelling uniformity and permanent availability. The problem of stability still exists. Monoclonal antibody-horseradish peroxidase (McAB-HREQ) conjugates produced in our laboratory showed variable stability. After extensive testing
This paper presents a nickel-coated immunoassay chip fabricated by electroplating technology for Uricase protein. The Taguchi method was adopted to determine the optimal electroplating condition. The considered factors that affect the performance of nickel-coated chip included current density of electroplating, operation temperature, and pH of electroplating buffer, etc. As a result of systematic electroplating approach, a stable and optimal chip
A high-Tc dc SQUID (superconducting quantum interference device) gradiometer was developed for magnetic immunoassays where magnetic nanoparticles are used as markers to detect biological reactions. The gradiometer was fabricated on a 5 × 10 mm2 SrTiO3 bicrystal substrate and has a gradiometer resolution of 2.1 pT cm-1 Hz-1\\/2. A magnetic signal was detected from a sample of 1 µl of
F. Öisjöen; P. Magnelind; A. Kalabukhov; D. Winkler
Functional magnetic nanoparticles are prepared and characterized for protein detection in a magnetic separation channel. This detection method is based on a competitive immunoassay of magnetic separation in thin channels using functional magnetic nanoparticles. We used protein AIgG complex to demonstrate the feasibility. Free IgG and fixed number of IgG-labeled microparticles were used to compete for limited sites of protein
Summary A murine monoclonal antibody (mAb) was generated that recognizes hemoglobin (Hb) H, the tetrameric form (ß4) of human ß-globin chains. The antibody ß4-1 (?1, ?) does not react with Hbs A, F, Bart's, or isolated ß chains, indicating that the antibody recognizes an epitope comprised of multiple ß chains. A simple, rapid, and sensitive enzyme immunoassay was established to
M. Shyamala; C. R. Kiefer; H. Moscoso; F. A. Garver
ABSTRACT: A number,of strategies have been advocated,to increase the number,of lung donors including: 1) improvement,in donor resuscitation; 2) better methods,of lung preservation; 3) extension,of the lung donor selection criteria; 4) development,of a living-related lung donor programme;,and 5) utilisation of nonheart,beating donors. Other strategies such as the split-lung technique and techniques of lung reduction to accommodate,large lungs into a small-size recipient
M. de Perrot; W. Weder; G. A. Patterson; S. Keshavjee
Cushing's syndrome results from chronic inappropriate exposure to excessive glucocorticoid concentrations. Low-dose dexamethasone suppression, late-night salivary cortisol, and 24-h urinary free cortisol are regarded as screening tests of first choice. Consequently, measurement of circulating cortisol (e. g., in serum, saliva, and urine) is mandatory in the diagnostic workup of suspected patients. The particular analytical procedure needs to be chosen carefully. Antibody-based immunoassays offer several potential advantages: they require small volumes and are widely available, relatively cheap, and easy to handle. Modern (ideally automated) systems also have a rapid turnaround time on a large number of samples and demonstrate high analytical accuracy. However, there are some important pitfalls. Inadequate standardization and poor interlaboratory performance remain problematic and precise reference ranges are lacking for some of the newer assays. Immunoassays are also susceptible to error due to cross-reactivity with cortisol metabolites or exogenous glucocorticoids. In contrast, steroid analysis by modern chromatographic and mass spectrometric techniques is largely independent from such interference and is therefore regarded as diagnostic gold standard. To date, however, these procedures are costly, time-consuming, and at least at present restricted to a limited number of specialized centers. This review puts special emphasis on the potential advantages of salivary cortisol analysis by immunoassays. It has been shown in numerous studies that such an approach allows excellent identification of hypercortisolemic states. In this context, use of automated systems may allow for broader use of this diagnostic tool. PMID:23417245
We describe a multiplex electrochemical immunoassay based on the use of gold nanoparticle (Au-NP) probes and immunochromatographic strips (ISs). The approach takes advantage of the speed and low cost of the conventional IS tests and the high sensitivities of the nanoparticle-based electrochemical immunoassays. Rabbit IgG(R-IgG) and human IgM (H-IgM) were used as model targets for the demonstration of the proof of concept. The Au-NPs based sandwich immunoreactions were performed on the IS, and the captured gold nanoparticle labels on the test zones were determined by highly-sensitive stripping voltammetric measurement of the dissolved gold ions (III) with a carbon paste electrode. The detection limits are 1.0 and 1.5 ng/mL with the linear ranges of 2.5-250 ng/mL for quantitative detection of R-IgG and H-IgM, respectively. The total assay time is around 25 minutes. Such multiplex electrochemical immunoassay could be readily highly multiplexed to allow simultaneous parallel detection of numerous proteins and is expected to open new opportunities for protein diagnostics and biosecurity.
A digital microfluidic platform for performing heterogeneous sandwich immunoassays based on efficient handling of magnetic beads is presented in this paper. This approach is based on manipulation of discrete droplets of samples and reagents using electrowetting without the need for channels where the droplets are free to move laterally. Droplet-based manipulation of magnetic beads therefore does not suffer from clogging of channels. Immunoassays on a digital microfluidic platform require the following basic operations: bead attraction, bead washing, bead retention, and bead resuspension. Several parameters such as magnetic field strength, pull force, position, and buffer composition were studied for effective bead operations. Dilution-based washing of magnetic beads was demonstrated by immobilizing the magnetic beads using a permanent magnet and splitting the excess supernatant using electrowetting. Almost 100% bead retention was achieved after 7776 fold dilution-based washing of the supernatant. Efficient resuspension of magnetic beads was achieved by transporting a droplet with magnetic beads across five electrodes on the platform and exploiting the flow patterns within the droplet to resuspend the beads. All the magnetic-bead droplet operations were integrated together to generate standard curves for sandwich heterogeneous immunoassays on Human Insulin and Interleukin-6 (IL-6) with a total time to result of seven minutes for each assay.
Sista, Ramakrishna S.; Eckhardt, Allen E.; Srinivasan, Vijay; Pollack, Michael G.; Palanki, Srinivas; Pamula, Vamsee K.
There are often discrepancies when using different methods to measure anti-Toxoplasma gondii IgG levels in patient samples. The diagnostic performance of a chemiluminescent immunoassay (CLIA) and an enzyme-linked fluorescent assay (ELFA) used as confirmatory tests for samples identified as positive or equivocal by an electrochemiluminescent immunoassay (ECLIA) were examined. Cut-off values were those stated by the manufacturer, and Western blot was used to confirm the results of all methods. All samples identified as positive by ECLIA (n=93) were confirmed as positive by Western blot, as were 14 of the 28 samples identified as equivocal. When these 121 samples were retested, the sensitivities of CLIA and ELFA were 64.4% and 73.8%, respectively. Both methods exhibited a specificity of 100%. This study confirms that the results obtained from the different immunoassays are not comparable, and neither CLIA nor ELFA should be used to confirm ECLIA results, which should instead be confirmed by methods such as Western blot or Sabin-Feldman dye test. PMID:23141993
Acceptance of elderly living kidney donors remains controversial due to the higher incidence of comorbidity and greater risk of postoperative complications. This is a review of publications in the English language between 2000 and 2013 about renal transplantation from elderly living donors to determine trends and effects of donation, and the outcomes of such transplantation. The last decade witnessed a 50% increase in living kidney donor transplants, with a disproportionate increase in donors >60 years. There is no accelerated loss of kidney function following donation, and the incidence of established renal failure (ERF) and hypertension among donors is similar to that of the general population. The overall incidence of ERF in living donors is about 0.134 per 1000 years. Elderly donors require rigorous assessment and should have a predicted glomerular filtration rate of at least 37.5?mL/min/1.73?m2 at the age of 80. Though elderly donors had lower glomerular filtration rate before donation, proportionate decline after donation was similar in both young and elderly groups. The risks of delayed graft function, acute rejection, and graft failure in transplants from living donors >65 years are significantly higher than transplants from younger donors. A multicentred, long-term, and prospective database addressing the outcomes of kidneys from elderly living donors is recommended.
A novel, noncompetitive immunoassay applicable to the measurement of small molecules including ovarian steroids is described. Using monoclonal antibodies with the ability to recognize both beta-typic and alpha-typic binding sites, a new simplified, sensitive, and specific immunoassay system has been developed. The initial work of this development is presented, along with preliminary results for a novel immunoassay for estradiol. PMID:1755457
In this paper, we demonstrate the possibility to use magnetic nanoparticles as immunosupports for allergy diagnosis. Most\\u000a immunoassays used for immunosupports and clinical diagnosis are based on a heterogeneous solid-phase system and suffer from\\u000a mass-transfer limitation. The nanoparticles colloidal behavior and magnetic properties bring the advantages of homogeneous\\u000a immunoassay, i.e., species diffusion, and of heterogeneous immunoassay, i.e., easy separation of
Bruno Teste; Frédéric Kanoufi; Stéphanie Descroix; Pascal Poncet; Thomas Georgelin; Jean-Michel Siaugue; Jan Petr; Anne Varenne; Marie-Claire Hennion
Two solid phase immunoassays, an electrochemiluminescent immunoassay (ECLIA) and a magnetic particle fluorogenic immunoassay (MPFIA) were evaluated and compared for bacterial detection. Briefly, the ECLIA is based on a redox reaction between ruthenium (II)-trisbipyridyl Ru[(bpy)3]2+ labeled antibody and the excess of tripropylamine, which generates photons. The entire reaction is carried on the near surface area between the spherical magnetic beads
Objective: Standard lung donor criteria have been established on opinions and individual experiences rather than on existing evidence. Since the scarcity of donor organs is one of the major limitations to lung transplantation, extension of donor lung criteria might considerably increase the donor pool. This study therefore evaluates the outcome, achieved with the use of extended donors versus standard donors
Clemens Aigner; Guenther Winkler; Peter Jaksch; Gernot Seebacher; Gyorgy Lang; Sharokh Taghavi; Wilfried Wisser; Walter Klepetko
The first example of an activated phosphonated trifunctional chelate (TFC) is presented, which combines a non-macrocyclic coordination site for lanthanide coordination based on two aminobis-methylphosphonate coordinating arms, a central bispyrazolylpyridyl antenna and an N-hydroxysuccinimide ester in para position of the central pyridine as an activated function for the labeling of biomaterial. The synthesis of the TFC is presented together with photo-physical studies of the related Tb and Eu complexes. Excited state lifetime measurements in H2O and D2O confirmed an excellent shielding of the cation from water molecules with a hydration number of zero. The Tb complex provides a high photoluminescence (PL) quantum yield of 24% in aqueous solutions (0.01 M Tris-HCl, pH 7.4) and a very long luminescence lifetime of 2.6 ms. The activated ligand was conjugated to different biological compounds such as streptavidin, and a monoclonal antibody against total prostate specific antigen (TPSA). In combination with AlexaFluor647 (AF647) and crosslinked allophycocyanin (XL665) antibody (ABs) conjugates, homogeneous time-resolved Fluorescence Resonance Energy Transfer (FRET) immunoassays of TPSA were performed in serum samples. The Tb donor-dye acceptor FRET pairs provided large Förster distances of 5.3 nm (AF647) and 7.1 nm (XL665). A detailed time-resolved FRET analysis of Tb donor and dye acceptor PL decays revealed average donor-acceptor distances of 4.2 nm (AF647) and 6.3 nm (XL665) within the sandwich immunocomplex and FRET efficiencies of 0.79 and 0.68, respectively. Very low detection limits of 1.4 ng mL(-1) (43 pM) and 2.4 ng mL(-1) (74 pM) TPSA were determined using a KRYPTOR fluorescence immunoanalyzer. These results demonstrate the applicability of our novel Tb-bioconjugates for highly sensitive clinical diagnostics. PMID:23851931
Living donation is a common procedure in the United States. Substantial variation exists among transplant centers in their protocols and exclusion criteria for potential living donors. In the absence of clinical trial data to guide decisions about exclusion criteria, knowledge of current practices is an important first step in guiding the formulation of donor protocols as well as future studies. Certain trends in live donation practices have become apparent from surveys of transplant programs over the past few decades. Over the past 25 years, opposition in the US to living unrelated donation has gone from strong to essentially nonexistent. With respect to donor age, programs have become less strict regarding upper age limits, but stricter regarding younger donor candidates. Protocols regarding kidney function, blood pressure and diabetes screening also continue to evolve. Although donor follow up is mandated by the OPTN for two years after donation, a majority of donors are lost to follow up by one year. The most commonly cited barriers to donor follow up include donor inconvenience, cost issues including reimbursement to care providers, as well as direct and indirect costs to donors. Here, we review the current knowledge about living donor practices in the U.S.
Background It is important to understand donor return behavior. Converting first time donors to become repeat donors is essential for maintaining an adequate blood supply. Methods Characteristics of 241,552 whole blood (WB) donations from first time (FT) and repeat (RPT) donors who donated in 2008 at the 5 blood centers in China were compared. A subset of 54,394 WB donors who donated between January 1 and March 31, 2008 were analyzed for their return behavior in 2008 following the index donation using logistic regression. Results Of all donations, 64% was from FT donors. Donors with self-reported previous donations tended to be male, older, married, donated larger volume (?300mL), and were heavier in weight. Among donors who donated from January to March, 2008, 14% returned for subsequent WB donations by the end of 2008. The number of previous donations and blood collection location were the two strongest predictors for making subsequent donations. Donors with 1, 23 and more than 3 previous donations were 3.7, 5.7, and 11.0 times more likely to return than FT donors. Those who donated in a blood collection vehicle were 4 times more likely to return than those who donated at a blood center. Being female, younger and of a lower education level (? middle school) were positively associated with subsequent return blood donation during the follow-up period observed in this study. Conclusion Most of the Chinese blood supply is from first time donors. Strategies aimed at encouraging current donors to become repeat donors are needed.
Highly sensitive and specific, quantitative assays are needed to detect varicella-zoster virus (VZV) immu- noglobulin G in human sera, particularly for determining immune status and response following vaccination. A time-resolved fluorescence immunoassay (TRFIA) has been developed, and its performance was compared to that of two commercial enzyme immunoassays (EIAs) and Merck glycoprotein EIA (gpEIA). The TRFIA had equivalent sensitivity (97.8%)
P. A. C. Maple; J. Gray; J. Breuer; G. Kafatos; S. Parker; D. Brown
Fatty liver is a significant risk factor for liver transplantation, and accounts for nearly half of the livers rejected from the donor pool. We hypothesized that metabolic preconditioning via ex vivo perfusion of the liver graft can reduce fat content and increase post-transplant survival to an acceptable range. We describe a perfusate medium containing agents that promote the defatting of hepatocytes and explanted livers. Defatting agents were screened on cultured hepatocytes made fatty by pre-incubation with fatty acids. The most effective agents were then used on fatty livers. Fatty livers were isolated from obese Zucker rats and normothermically perfused with medium containing a combination of defatting agents. This combination decreased the intracellular lipid content of cultured hepatocytes by 35% over 24 hours, and of perfused livers by 50% over 3 hours. Metabolite analysis suggests that the defatting cocktail upregulated both lipid oxidation and export. Furthermore, gene expression analysis for several enzymes and transcription factors involved in fatty acid oxidation and triglyceride clearance were elevated. We conclude that a cocktail of defatting agents can be used to rapidly clear excess lipid storage in fatty livers, thus providing a new means to recondition donor livers deemed unacceptable or marginally acceptable for transplantation.
Nagrath, Deepak; Xu, Hongzhi; Tanimura, Yoko; Zuo, Rongjun; Berthiaume, Francois; Yarmush, Martin L.
A chemiluminescent, microparticle-membrane capture immunoassay (CLIA/MMC) for the detection of antibody to hepatitis B core antigen (anti-HBc) is described. The assay utilizes recombinant hepatitis B core antigen coupled to carboxylated latex microparticles. Human polyclonal IgG anti-HBc labelled with acridinium competes with antibody in the sample for a limited number of binding sites on the solid phase. After a 40 min incubation at 40 degrees C, the reaction mixture is transferred to a glass fiber capture membrane and washed. A chemiluminescent signal is produced by addition of alkaline peroxide and is quantitated on a semi-automated reader as described. The CLIA/MMC assay was compared with standard EIA and RIA procedures (Corzyme and Corab, respectively, Abbott Laboratories, North Chicago, IL). Assay sensitivities were RIA greater than CLIA/MMC greater than EIA. A population of 200 normal blood donors showed nearly identical distributions with the CLIA/MMC and RIA (mean = 11% inhibition, SD = 13% for both), compared with the EIA (mean = 13% inhibition, SD = 15%). With a selected plasma population (n = 307), the CLIA/MMC immunoassay showed an excellent correlation (r = 0.94) with both the EIA and RIA procedures. Association of anti-HBc reactivity near assay cutoffs with antibody to hepatitis B surface antigen suggested relative specificity in the order RIA greater than CLIA/MMC greater than EIA. The CLIA/MMC procedure, which can be readily automated, provides a non-istopic alternative to current EIA testing with performance more nearly equivalent to RIA. PMID:2230137
Wolf-Rogers, J; Weare, J A; Rice, K; Robertson, E F; Guidinger, P; Khalil, O S; Madsen, G
This paper describes a novel on-chip microarray platform based on an electrochemiluminescence resonance energy transfer (ECL-RET) strategy for rapid assay of cancer cell surface biomarkers. This platform consists of 64 antigen-decorated CdS nanorod spots with the diameter of 1.0 cm uniformly distributed on 16 indium tin oxide (ITO) strips, which is coated with a multichannel decorated polydimethylsiloxane (PDMS) slice to realize multiplexed determination of antigens. To shorten the immune reaction time in the microchannels and simplify the device, magnetic stirring and four-channel universal serial bus (USB) ports for plug-and-play were used. When Ru(bpy)(3)(2+) labeled antibodies were selectively captured by the corresponding antigens on the CdS nanorod spot array, ECL-RET from the CdS nanorod (donor) by cathodic emission in the presence of K(2)S(2)O(8) to Ru(bpy)(3)(2+) (acceptor) occurred. With signal amplification of Ru(bpy)(3)(2+) and competitive immunoassay, carcinoembryonic antigen (CEA), ?-fetoprotein (AFP), and prostate specific antigen (PSA) as models were detected on this microfluidic device via recording the increased ECL-RET signals on electrode surfaces. Furthermore, this multiplexed competitive immunoassay was successfully used for detecting cancer cell surface antigens via the specific antibody-cell interactions and cell counting via cell surface receptors and antigens on the CdS nanorod surface. This platform provides a rapid and simple but sensitive approach with microliter-level sample volume and holds great promise for multiplexed detection of antigens and antigen-specific cells. PMID:22494075
Biological sulfate reduction is widely used for treating sulfate-containing wastewaters from industries such as mining, tannery, pulp and paper, and textiles. In biological reduction, sulfate is converted to hydrogen sulfide as the end product. The process is, therefore, ideally suited for treating metal-containing wastewater from which heavy metals are simultaneously removed through the formation of metal sulfides. Metal sulfide precipitates are more stable than metal hydroxides that are sensitive to pH change. Theoretically, conversion of 1 mol of sulfate requires 0.67 mol of chemical oxygen demand or electron donors. Sulfate rich wastewaters are usually deficient in electron donors and require external addition of electron donors in order to achieve complete sulfate reduction. This paper reviews various electron donors employed in biological sulfate reduction. Widely used electron donors include hydrogen, methanol, ethanol, acetate, lactate, propionate, butyrate, sugar, and molasses. The selection criteria for suitable electron donors are discussed. PMID:17572039
The Research Donor Program (RDP) serves as a central repository for the collection and distribution of whole blood samples from healthy volunteers to the Frederick National Lab Investigators for in vitro research use. Approved projects can obtain timely and inexpensive samples through OHS. Employees of the Frederick National Lab and Fort Detrick community may volunteer to be donors. Monetary compensation is provided for donor participation. The program is administered by Occupational Health Services.
Purpose To assess the relationship between donor factors and 5-year corneal graft survival in the Cornea Donor Study (CDS). Methods Donor corneas met criteria established by the Eye Bank Association of America, had an endothelial cell density of 23003300/mm2, and were determined to be of good to excellent quality by the eye banks. Donor corneas were assigned using a random approach and surgeons were masked to information about the donor cornea including donor age. Surgery and post-operative care were performed according to the surgeons usual routines and subjects were followed for five years. Donor and donor cornea factors were evaluated for their association with graft failure, which was defined as a regraft or a cloudy cornea that was sufficiently opaque to compromise vision for a minimum of three consecutive months. Results Graft failure was not significantly associated with the type of tissue retrieval (enucleation versus in situ), processing factors, timing of use of the cornea, or to characteristics of the donor or the donor cornea. Adjusting for donor age did not affect the results. Conclusion Donor and donor cornea characteristics do not impact graft survival rates for corneas comparable in quality to those used in this study.
Sugar, Joel; Montoya, Monty; Dontchev, Mariya; Tanner, Jean Paul; Beck, Roy; Gal, Robin; Gallagher, Shawn; Gaster, Ronald; Heck, Ellen; Holland, Edward J.; Kollman, Craig; Malling, Jackie; Mannis, Mark J.; Woody, Jason
A novel rolling circle amplification (RCA) immunoassay based on DNA enriching magnetic nanoparticles and assembled fluorescent DNA nanotags, magnetic nanoparticles-RCA immunoassay, is developed as a versatile fluorescence assay platform for highly sensitive proteins detection. PMID:22301574
The disparity between the number of available deceased liver donors and the number of patients awaiting transplantation continues to be an ongoing issue predisposing to death on the liver transplant waiting list. Deceased donor shortage strategies including the use of extended donor-criteria deceased donor grafts, split liver transplants, and organs harvested after cardiac death have fallen short of organ demand. Efforts to raise donor awareness are ongoing, but the course has been arduous to date. Living donor transplantation is a means to access an unlimited donor organ supply and offers potential advantages to deceased donation. Donor safety remains paramount demanding improvements and innovations in both the donor and recipient operations to ensure superior outcomes. The specialty operation is best preformed at centers with specific expertise and shuttling of select patients to these centers supported by third party payers is critical. Training future surgeons at centers with this specific experience can help disseminate this technology to improve local availability. Ongoing research in immunosuppression minimization, withdrawal and tolerance induction may make living donation a desired first-line operation rather than a necessary albeit less-desirable option. This chapter summarizes the progress of living liver donation and its potential applications. PMID:23397534
A living-donor kidney transplant offers a child at the terminal stages of renal disease better functional recovery and quality of life than an organ from a deceased donor. Before starting the procedure for a living-donor transplant, however, it is necessary to establish if it is really safe. There are diseases, such as focal segmental glomerulosclerosis, atypical HUS and membranoproliferative glomerulonephritis with dense deposits, for which living donation is not recommended given the high incidence of recurrence of the disease but also the frequent loss of the graft. Regarding the selection of the donor, an increased risk of acute rejection has been reported for donors older than 60-65 years and a worsening of the renal outcome if the donor's weight is equal to or less than the recipient's. Finally, it is necessary to take into consideration that complications may arise in the donor both in the perioperative period and in the long term. In conclusion, kidney transplant from a living donor is a natural choice within the pediatric setting. The parents, usually young and highly motivated to donate, are the ideal donors. However, although the risks associated with donation are minimal, they are not totally absent, and consequently it is mandatory to follow standardized procedures according to the guidelines issued by the Centro Nazionale Trapianti. PMID:21341241
Background Reduced kidney function confers a higher risk of acute kidney injury at the time of an inciting event, such as sepsis. Whether the same is true in those with reduced renal mass from living kidney donation is unknown. Methods We conducted a population-based matched cohort study of all living kidney donors in the province of Ontario, Canada who underwent donor nephrectomy from 1992 to 2009. We manually reviewed the medical records of these living kidney donors and linked this information to provincial health care databases. Non-donors were selected from the healthiest segment of the general population. Results There were 2027 donors and 20 270 matched non-donors. The median age was 43 years (interquartile range 3450) and individuals were followed for a median of 6.6 years (maximum 17.7 years). The primary outcome was acute dialysis during any hospital stay. Reasons for hospitalization included infectious diseases, cardiovascular diseases and hematological malignancies. Only one donor received acute dialysis in follow-up (6.5 events per 100 000 person-years), a rate which was statistically no different than 14 non-donors (9.4 events per 100 000 person-years). Conclusions These results are reassuring for the practice of living kidney donation. Longer follow-up of this and other donor cohorts will provide more precise estimates about this risk.
Lam, Ngan; Huang, Anjie; Feldman, Liane S.; Gill, John S.; Karpinski, Martin; Kim, Joseph; Klarenbach, Scott W.; Knoll, Greg A.; Lentine, Krista L.; Nguan, Chris Y.; Parikh, Chirag R.; Prasad, G. V. Ramesh; Treleaven, Darin J.; Young, Ann; Garg, Amit X.
The worldwide shortage of adequate donor organs implies that living donor liver transplantation represents a valuable alternative to cadaveric transplantation. In addition to the complex surgical procedure the correct identification of eligible donors and recipients plays a decisive role in living donor liver transplantation. Donor safety must be of ultimate priority and overrules all other aspects involved. In contrast to the slightly receding numbers in Europe and North America, in recent years Asian programs have enjoyed constantly increasing living donor activity. The experience of the past 15 years has clearly demonstrated that technical challenges of both bile duct anastomosis and venous outflow of the graft significantly influence postoperative outcome. While short-term in-hospital morbidity remains increased compared to cadaveric transplantation, long-term survival of both graft and patient are comparable or even better than in deceased donor transplantation. Especially for patients expecting long waiting times under the MELD allocation system, living donor liver transplantation offers an excellent therapeutic alternative. Expanding the so-called "Milan criteria" for HCC patients with the option for living donor liver transplantation is currently being controversially debated. PMID:20676595
In this letter, the authors investigate the electrical properties of nitrogen related shallow thermal donor (STD) candidates and their concentrations under different doping conditions by means of density functional theory. Experimentally, the existence of STDs containing one nitrogen atom and both even and odd numbers of oxygen atoms has been proposed. However, so far first principles studies have not presented a candidate for the latter. Here, they show that the NO defect possesses a shallow donor level. Adding one or two more oxygen atoms results in the donor level to become shallower. The fraction of shallow nitrogen related donors to N dimers increases in material with low concentration of nitrogen.
Summary Neutral organic electron donors, featuring pyridinylideneimidazolylidene, pyridinylidenebenzimidazolylidene and imidazolylidenebenzimidazolylidene linkages are reported. The pyridinylidenebenzimidazolylidene and imidazolylidenebenzimidazolylidene hybrid systems were designed to be the first super electron donors to convert iodoarenes to aryl radicals at room temperature, and indeed both show evidence for significant aryl radical formation at room temperature. The stronger pyridinylideneimidazolylidene donor converts iodoarenes to aryl anions efficiently under appropriate conditions (3 equiv of donor). The presence of excess sodium hydride base has a very important and selective effect on some of these electron-transfer reactions, and a rationale for this is proposed.
Garnier, Jean; Thomson, Douglas W; Zhou, Shengze; Jolly, Phillip I; Berlouis, Leonard E A
Phenylephrine, an ?(1) -adrenergic agonist, and methamphetamine, a prescription drug and substance of abuse, have similar chemical structures and thus have the potential to cross-react in qualitative screening tools such as a urine drug screening (UDS) performed by immunoassay. This cross-reactivity may yield a false-positive result that may affect the provision of care in certain patient populations and clinical situations. We describe a 36-year-old woman with confirmed brain death after a short hospital stay who had an initial UDS that was negative for methamphetamine. The patient was assessed for potential organ donation, which included obtaining a follow-up UDS. A urine sample was obtained after being hospitalized for 36 hours, which tested positive for methamphetamine, with no suspected ingestion of the target substance. Confirmatory laboratory testing indicated that intravenous phenylephrine and its metabolites were the likely cause of the false-positive UDS. However, the patient was not deemed to be a suitable candidate for organ donation, but clear documentation of the reason for denial of organ donation was not available in the patient's medical record. To our knowledge, this is the first case published in the English-language literature that describes the clinical occurrence of apparent immunoassay cross-reactivity of methamphetamine and phenylephrine that resulted in a false-positive UDS for methamphetamine. In addition, this report describes the potential implications of this situation on clinical care, including organ donation acceptance. Toxicology screening in the emergency department and intensive care unit is a tool to assist in the diagnosis of medical conditions, but it may not always be reliable. Therefore, positive immunoassay results that may change the management of a patient's condition should be quickly verified with confirmatory testing to minimize unfavorable consequences. PMID:22499397
Immunoassays are important tools for the rapid detection and identification of pathogens, both clinically and in the research laboratory. An immunoassay with the potential for the detection of influenza was developed and tested using hemagglutinin (HA), a commonly studied glycoprotein found on the surface of influenza virions. Gold nanoparticles were synthesized, which present multiple peptide epitopes, including the HA epitope, in order to increase the gravimetric response achieved with the use of a QCM immunosensor for influenza. Specifically, epitopes associated with HA and FLAG peptides were affixed to gold nanoparticles by a sixmer PEG spacer between the epitope and the terminal cysteine. The PEG spacer was shown to enhance the probability for interaction with antibodies by increasing the distance the epitope extends from the gold surface. These nanoparticles were characterized using thermogravimetric analysis, transmission electron microscopy, matrix-assisted laser desorption/ionization-time of flight, and 1H nuclear magnetic resonance analysis. Anti-FLAG and anti-HA antibodies were adhered to the surface of a QCM, and the response of each antibody upon exposure to HA, FLAG, and dual functionalized nanoparticles was compared with binding of Autiopronin nanoparticles and H5 HA proteins from influenza virus (H5N1). Results demonstrate that the immunoassay was capable of differentiating between nanoparticles presenting orthogonal epitopes in real-time with minimal nonspecific binding. The detection of H5 HA protein demonstrates the logical extension of using these nanoparticle mimics as a safe positive control in the detection of influenza, making this a vital step in improving influenza detection methodology.
Miller, Scott A.; Hiatt, Leslie A.; Keil, Robert G.; Wright, David W.; Cliffel, David E.
Here we describe the first example of using self-propelled antibody-functionalized synthetic catalytic microengines for capturing and transporting target proteins between the different reservoirs of a lab-on-a-chip (LOC) device. A new catalytic polymer/Ni/Pt microtube engine, containing carboxy moieties on its mixed poly(3,4-ethylenedioxythiophene) (PEDOT)/COOH-PEDOT polymeric outermost layer, is further functionalized with the antibody receptor to selectively recognize and capture the target protein. The new motor-based microchip immunoassay operations are carried out without any bulk fluid flow, replacing the common washing steps in antibody-based protein bioassays with the active transport of the captured protein throughout the different reservoirs, where each step of the immunoassay takes place. A first microchip format involving an 'on-the-fly' double-antibody sandwich assay (DASA) is used for demonstrating the selective capture of the target protein, in the presence of excess of non-target proteins. A secondary antibody tagged with a polymeric-sphere tracer allows the direct visualization of the binding events. In a second approach the immuno-nanomotor captures and transports the microsphere-tagged antigen through a microchannel network. An anti-protein-A modified microengine is finally used to demonstrate the selective capture, transport and convenient label-free optical detection of a Staphylococcus aureus target bacteria (containing proteinA in its cell wall) in the presence of a large excess of non-target (Saccharomyces cerevisiae) cells. The resulting nanomotor-based microchip immunoassay offers considerable potential for diverse applications in clinical diagnostics, environmental and security monitoring fields. PMID:23123833
A solid-phase enzyme immunoassay involving microtiter plates was proposed by Microgenics to screen buprenorphine in urine. The intra-assay precision at 10 ng/mL was 7.7% (coefficient of variation). The immunoassay was determined to have no cross-reactivity with codeine, dihydrocodeine, morphine, ethylmorphine, 6-monoacetylmorphine, methadone, pholcodine, propoxyphene, dextromoramide, and dextromethorphan at 1 and 10 mg/L. A low cross-reactivity (3% at 1 ng/mL) was observed at low concentrations of norbuprenorphine. After comparing this new immunological test (Singlestep ELISA) for 76 urine specimens with our validated high-performance liquid chromatography-electrospray mass spectrometry (HPLC-ES-MS) procedure, an optimum cutoff concentration of 2 ng/mL was determined for the kit. At this cutoff, the screening assay was able to determine more than 90% of true results with 43.4% true positives and 48.7% true negatives. Four positive urines (5.3%) were not confirmed by HPLC-ES-MS. In only one case, the negative urine test was confirmed as positive by HPLC-ES-MS (buprenorphine: 62.5 ng/mL). Buprenorphine concentrations determined by HPLC-ES-MS ranged from 1.2 to 1052 ng/mL. Of the four potential adulterants (hypochloride 50 mL/L, sodium nitrite 50 g/L, liquid soap 50 mL/L, and sodium chloride 50 g/L) that might be added to a positive urine specimen, none were able to cause a false-negative response by the immunoassay. The results of this study support the concept that the Singlestep ELISA for buprenorphine determination in urine should be considered as a new, valided screening procedure. PMID:12670004
Retrospective serosurveys were conducted to determine the prevalence of antibody to phase-I Coxiella burnetii among humans in various locations of north-east Africa. Sera were tested by the enzyme immunoassay (EIA). Initially the EIA was compared with the standard indirect fluorescent antibody (IFA) method for the detection of antibody to C. burnetii. Results indicated that the EIA was slightly less sensitive (88%), but highly specific (94%) and less subjective than the IFA technique. EIA was subsequently adopted for estimating prevalences in the studied human populations. Data obtained by EIA indicated that the prevalence of C. burnetii antibody among adult Egyptian blood donors was 20% (n = 358) in the Suez Canal area, 16% (n = 501) in the Nile Valley and 10% (n = 427) in the Nile Delta. Among adult patients with acute, undifferentiated fever in Egypt, the prevalence was 28% (n = 50) of acute sera, with seroconversion in 12% of convalescent sera. Antibody to C. burnetii was detected by EIA in the sera of 25% (n = 71) of cattle workers in Egypt, 10% (n = 100) of housewives in Sudan, and 37% (n = 104) of adults in north-west Somalia. Following a fever outbreak affecting all ages in northern Sudan, IgG antibody to C. burnetii was present in 54% of the febrile persons (n = 185) and in 53% of afebrile persons (n = 186). IgM antibody to C. burnetii was demonstrated in 29% of the febrile persons and 15% of the afebrile persons. These results implicate C. burnetii as a possibly important and under-reported cause of human disease and undiagnosed fevers in north-east Africa. PMID:7783275
Botros, B A; Soliman, A K; Salib, A W; Olson, J; Hibbs, R G; Williams, J C; Darwish, M; el Tigani, A; Watts, D M
Monoclonal antibodies, epidemic strains of influenza A and B viruses, conjugates were studied by fluorescence immunoassay with temporary resolution using equipment of different companies. Differences and specificity of monoclonal antibodies to influenza A and B viruses were demonstrated. The highest sensitivity of the method with the test system used was determined, being 20 ng/ml of viral protein. The method was shown to be useful for influenza virus detection both in solutions containing purified virions and in virus-containing allantoic preparations. It was established that virological studies could be carried out using conjugates and knock-down microplates of the national make alongside with foreign ones. PMID:2202151
Ivanova, V T; Ponomareva, I V; Shakhanina, K L; Iakhno, M A; Slepushkin, A N; Savitski?, A P
An optical multiplexed homogeneous (liquid phase) immunoassay based on FRET from a terbium complex to eight different fluorescent dyes is presented. We achieved highly sensitive parallel detection of four different lung cancer specific tumor markers (CEA, NSE, SCC and CYFRA21-1) within a single assay and show a proof-of-principle for 5- fold multiplexing. The method is well suited for fast and low-cost miniaturized point-of-care testing as well as for highthroughput screening in a broad range of in-vitro diagnostic applications.
Geißler, D.; Hill, D.; Löhmannsröben, H.-G.; Thomas, E.; Lavigne, A.; Darbouret, B.; Bois, E.; Charbonnière, L. J.; Ziessel, R. F.; Hildebrandt, N.
We report here new monoclonal antibodies (Mabs) numbered AIA-8 through AIA-12 produced using the same methods used to produce AIA-1, and a new Mab, IQ-7, produced with the same methods used for IQ-1. Our motivation in seeking these new clones was to increase the repertoire of available Mabs to insure adequate coverage of all known AIAs. Also, the mice used to produce these new hybridoma clones had been immunized about six months longer than those used to generate the first clones. Longer immunization is often associated with higher affinity Mabs and therefore more sensitive competition immunoassays. 15 refs., 2 figs., 2 tabs.
Vanderlaan, M.; Hwang, M.; Knize, M.G.; Watkins, E.; Felton, J.S.
A rapid and sensitive immunoassay for the determination of linear alkylbenzene sulfonates (LAS) is described. The method involves a sequential injection analysis (SIA) system equipped with a chemiluminescence detector and a neodymium magnet. Magnetic beads, to which an anti-LAS monoclonal antibody was immobilized, were used as a solid support in an immunoassay. The introduction, trapping and release of the magnetic
RuiQi Zhang; Koji Hirakawa; Daisuke Seto; Nobuaki Soh; Koji Nakano; Takashi Masadome; Kazumi Nagata; Kazuhira Sakamoto; Toshihiko Imato
Background: Hemolysis is regularly encountered in clinical specimens and often interferes with a variety of laboratory test methods. Although not widely recognized, immunoassays based on nonisotopic detection systems can also be affected by hemolysis. For this reason, we investigated the effect of differing amounts of hemolysis across a range of values for several immunoassays on the Ortho-Clinical Diagnostics ECi and
J. A. Snyder; M. W. Rogers; M. S. King; J. C. Phillips; J. F. Chapman; C. A. Hammett-Stabler
Immunoassay (IA) is a sensitive and selective approach for low level quantitation of drugs. Magnetic separation immunoassays use magnetic beads to facilitate the separation of bound labeled antigens from free antigens in solution. Digoxin was chosen for this study because low level analysis (ng?mL -1) in biological samples isrequired, antibodies to digoxin were commercially available and derivatization procedures for fluorescence
Zhe Tang; Kerstin Graefe; Clark March; H. Thomas Karnes
Objective:We investigated the mechanism by which the ARCHITECT cyclosporine (CsA) chemiluminescent microparticle immunoassay (CMIA) eliminates cross-reactivity to CsA metabolites AM1 and AM9, despite its use of a monoclonal antibody which shows cross-reactivity in fluorescence polarization immunoassays.
Elaine M. Brate; David M. Finley; Jonathan Grote; Shelley Holets-McCormack; Pan F. Ozaeta; David Pacenti; Joan E. Peart; Ryan E. Piktel; Carol S. Ramsay; Kevin R. Rupprecht; Sylvia C. Saldana; Thomas G. Spring; Sergey Y. Tetin; Beth C. Trudeau; Phil Wang; Helen Xie
We have directly compared enzyme-linked immunoassays (ELISAs) with bioluminescent immunoassays employing derivatives of the bioluminescent molecule aequorin, and have shown that detection of mucosal and serum antibodies is considerably more sensitive when detected by luminometry. Luminometry is based upon counting photons of light via phototubes and is generally similar to scintillation spectrometry. Current commercial luminometric technology employs a phototube which
Raymond J. Jackson; Kohtaro Fujihashi; Hiroshi Kiyono; Jerry R. McGhee
A new magnetic electrochemical immunoassay has been developed as a tool for biomonitoring exposures to organophosphate (OP) compounds, e.g., insecticides and chemical nerve agents, by directly detecting organophosphorylated acetylcholinesterase (OPAChE). This immunoassay uniquely incorporates highly efficient magnetic separation with ultrasensitive square wave voltammetry (SWV) analysis with quantum dots (QDs) as labels. A pair of antibodies was used to achieve the
To maintain healthy nonhuman primates for use in biomedical research, animals are routinely screened for several infectious agents at most facilities. Commonly, monkey serum samples are tested by conventional immunoassays, such as enzyme-linked immunosorbent assays (ELISAs) or Western blotting, for antibodies to specific infectious agents. For testing for antibodies against multiple agents in each sample, conventional immunoassays are laborious and
Imran H. Khan; Sara Mendoza; JoAnn Yee; Matthew Deane; Kodumudi Venkateswaran; Shan S. Zhou; Peter A. Barry; Nicholas W. Lerche; Paul A. Luciw
We developed a prototype magnetic immunoassay system using a high temperature superconductor (HTS) superconducting quantum interference device (SQUID) to investigate the performance and usability of the magnetic immunoassay. The system is designed to measure multiple samples and liquid samples, and it can work in an unshielded environment at a medical facility. To reduce the disturbance from environmental noise, the SQUID
A. Tsukamoto; K. Saitoh; D. Suzuki; N. Sugita; Y. Seki; A. Kandori; K. Tsukada; Y. Sugiura; S. Hamaoka; H. Kuma; N. Hamasaki; K. Enpuku
We report novel methods for detection of hepatitis B surface antigen (HBsAg) based on competitive and sandwiched magnetic immunoassays using functional magnetic nanoparticles in a thin channel. Magnetic nanoparticles labeled with hepatitis B antibody are flowed through a thin channel to form a predeposition layer for capturing HBsAg. Competitive and sandwiched magnetic immunoassays were studied and detection limit, linear range,
H. Y. Tsai; J. R. Chan; Y. C. Li; F. C. Cheng; C. Bor Fuh
While modern immunoassays provide sensitive and specific means for the quantitation of cytokines in biological fluids, heterophile antibodies are still a well-recognized cause of interference in the measurement of cytokines in these assays. We have developed a multiplexed fluorescent microsphere immunoassay for the simultaneous quantification of 10 cytokines in only 75 l of serum. During the development of this multiplexed
Thomas B Martins; Brian M. Pasi; Christine M. Litwin; Harry R. Hill
Immunoassays are bioanalytical methods in which the quantitation of the analyte depends on the reaction of an antigen (analyte) and an antibody. Immunoassays have been widely used in many important areas of pharmaceutical analysis such as diagnosis of diseases, therapeutic drug monitoring, clinical pharmacokinetic and bioequivalence studies in drug discovery and pharmaceutical industries. The importance and widespread of immunoassay methods in pharmaceutical analysis are attributed to their inherent specificity, high-throughput, and high sensitivity for the analysis of wide range of analytes in biological samples. Recently, marked improvements were achieved in the field of immunoassay development for the purposes of pharmaceutical analysis. These improvements involved the preparation of the unique immunoanalytical reagents, analysis of new categories of compounds, methodology, and instrumentation. The basic methodologies and recent advances in immunoassay methods applied in different fields of pharmaceutical analysis have been reviewed.
The capillary electrophoresis (CE) conditions for a competitive immunoassay of glucagon were optimized for highest sensitivity of the immunoassay and resolution of the electrophoretic peaks using a Box-Behnken design. Injection time, voltage ramp time, and separation voltage were varied between three levels and two responses, bound-to-free (B/F) ratio of the immunoassay peaks and resolution between the peaks, were measured. Analysis of variance was applied to fit a predictive model, and a desirability function was used to simultaneously optimize both responses. A 10 sec injection, 1.6 min ramp time, and a 22 kV separation voltage were the conditions found when high B/F was given more emphasis than high resolution. To test the model, calibration curves of a glucagon immunoassay were measured at the optimum and least optimum CE conditions. Optimal conditions increased the sensitivity of the immunoassay by 388% compared to the least optimum conditions while maintaining adequate resolution.
Lomasney, Anna R.; Guillo, Christelle; Sidebottom, Ashley M.; Roper, Michael G.
On 16 November 2005, we celebrated the milestone when 10 million donors had been registered in Bone Marrow Donors Worldwide (BMDW). Since then another million donors have been added in little more than a year. It seems an appropriate time for reassessment and to ask whether we are on the right track or not. We will do so by discussing
Severe donor organ shortage has provided the impetus for adult living donor liver transplantation (ALDLT). Despite rapid implementation and expansion of the procedure, outcome analysis of ALDLT is still incomplete. This study analyzed both donor and recipient outcomes after ALDLT at a single center. ALDLT performed at UCLA between August 1999 and November 2001 were reviewed retrospectively. Twenty recipients (14
Rafik M. Ghobrial; Sammy Saab; Charles Lassman; David S. K. Lu; Steven Raman; Piyagorn Limanond; Greg Kunder; Karyn Marks; Farin Amersi; Dean Anselmo; Pauline Chen; Douglas Farmer; Steven Han; Francisco Durazo; Leonard I. Goldstein; Ronald W. Busuttil
The efficacy and toxicity of donor leuko- cyte infusions (DLI) after unrelated donor bone marrow transplantation (BMT) is largely unknown. We identified 58 recipi- ents of unrelated DLI (UDLI) for the treatment of relapsed disease from the National Marrow Donor Program data- base. A retrospective analysis was per- formed to determine response, toxicity, and survival after UDLI and to identify
David L. Porter; Robert H. Collins; Christine Hardy; Nancy A. Kernan; William R. Drobyski; Sergio Giralt; Mary E. D. Flowers; James Casper; Pablo Parker; Rosemarie Mick; Bev Bate-Boyle; Joseph H. Antin
Women seeking fertility treatment using donor eggs can face challenges associated with recruiting suitable egg donors and negotiating the role that the donor may play in the life of the child. Social work in infertility clinics is an emerging area of practice and social work counsellors have an important role to play with parties involved in the egg donation process.
Bacillus anthracis is one of the most dangerous potential biological weapons, and it is essential to develop a rapid and simple method to detect B. anthracis spores in environmental samples. The immunoassay is a rapid and easy-to-use method for the detection of B. anthracis by means of antibodies directed against surface spore antigens. With this objective in view, we have produced a panel of monoclonal antibodies against B. anthracis and developed colorimetric and electrochemiluminescence (ECL) immunoassays. Using Meso Scale Discovery ECL technology, which is based on electrochemiluminescence (ECL) detection utilizing a sulfo-Tag label that emits light upon electrochemical stimulation (using a dedicated ECL plate reader, an electrical current is placed across the microplate with electrodes integrated into the bottom of the plate, resulting in a series of electrically induced reactions leading to a luminescent signal), a detection limit ranging between 0.3 × 10(3) and 10(3) CFU/ml (i.e., 30 to 100 spores per test), depending on the B. anthracis strain assayed, was achieved. In complex matrices (5 mg/ml of soil or simulated powder), the detection level (without any sample purification or concentration) was never altered more than 3-fold compared with the results obtained in phosphate-buffered saline. PMID:22773632
The use of bio- and chemiluminescence for the development of quantitative binding assays offers undoubted advantages over other detection systems, such as spectrophotometry, fluorescence, or radioactivity. Indeed, bio- and chemiluminescence detection provides similar, or even better, sensitivity and detectability than radioisotopes, while avoiding the problems of health hazards, waste disposal, and instability associated with the use of radioisotopes. Among bioluminescent labels, the calcium-activated photoprotein aequorin, originally isolated from Aequorea victoria and today available as a recombinant product, is characterized by very high detectability, down to attomole levels. It has been used as a bioluminescent label for developing a variety of highly sensitive immunoassays, using various analyte-aequorin conjugation strategies. When the analyte is a protein or a peptide, genetic engineering techniques can be used to produce protein fusions where the analyte is in-frame fused with aequorin, thus producing homogeneous one-to-one conjugation products, available in virtually unlimited amount. Various assays were developed using this strategy: a short review of the most interesting applications is presented, as well as the cloning, purification and initial characterization of an endothelin-1-aequorin conjugate suitable for developing a competitive immunoassay for endothelin-1, a potent vasoconstrictor peptide, involved in hypertension.
Method of highly sensitive registration of magnetic nanoparticles by their nonlinear magnetization is used in a novel sandwich-type immunoassay for detection of staphylococcal toxins in complex media of virtually any volume, with increasing sensitivity at higher sample volume. The signal is read out from the entire volume of a nontransparent 3D fiber structure employed as a solid phase, which provides large reaction surface, quick reagent mixing, as well as antigen immunofiltration directly in the course of the assay. The method has demonstrated near-linear dose-response curves within a wide range of ~3 decades, while detection of staphylococcal enterotoxin A (SEA) and toxic shock syndrome toxin (TSST) in neat milk without sample preparation. The limits of detection (LOD) as low as 4 and 10 pg/mL for TSST and SEA, respectively, were obtained in 2-h format using 30-mL samples. The second, 25-min format, showed the LOD of 0.1 and 0.3 ng/mL for the same toxins in a 150 ?L sample. The developed immunoassay can be applied in food safety control, in vitro diagnostics, and veterinary for a variety of research from express tests in the field to highly sensitive laboratory tests. PMID:23244173
Orlov, Alexey V; Khodakova, Julia A; Nikitin, Maxim P; Shepelyakovskaya, Anna O; Brovko, Fedor A; Laman, Alexander G; Grishin, Evgeny V; Nikitin, Petr I
Bacillus anthracis is one of the most dangerous potential biological weapons, and it is essential to develop a rapid and simple method to detect B. anthracis spores in environmental samples. The immunoassay is a rapid and easy-to-use method for the detection of B. anthracis by means of antibodies directed against surface spore antigens. With this objective in view, we have produced a panel of monoclonal antibodies against B. anthracis and developed colorimetric and electrochemiluminescence (ECL) immunoassays. Using Meso Scale Discovery ECL technology, which is based on electrochemiluminescence (ECL) detection utilizing a sulfo-Tag label that emits light upon electrochemical stimulation (using a dedicated ECL plate reader, an electrical current is placed across the microplate with electrodes integrated into the bottom of the plate, resulting in a series of electrically induced reactions leading to a luminescent signal), a detection limit ranging between 0.3 × 103 and 103 CFU/ml (i.e., 30 to 100 spores per test), depending on the B. anthracis strain assayed, was achieved. In complex matrices (5 mg/ml of soil or simulated powder), the detection level (without any sample purification or concentration) was never altered more than 3-fold compared with the results obtained in phosphate-buffered saline.
Plant pathogens are a serious problem for seed export, plant disease control and plant quarantine. Rapid and accurate screening tests are urgently required to protect and prevent plant diseases spreading worldwide. A novel multiplex detection method was developed based on microsphere immunoassays to simultaneously detect four important plant pathogens: a fruit blotch bacterium Acidovorax avenae subsp. citrulli (Aac), chilli vein-banding mottle virus (CVbMV, potyvirus), watermelon silver mottle virus (WSMoV, tospovirus serogroup IV) and melon yellow spot virus (MYSV, tospovirus). An antibody for each plant pathogen was linked on a fluorescence-coded magnetic microsphere set which was used to capture corresponding pathogen. The presence of pathogens was detected by R-phycoerythrin (RPE)-labeled antibodies specific to the pathogens. The assay conditions were optimized by identifying appropriate antibody pairs, blocking buffer, concentration of RPE-labeled antibodies and assay time. Once conditions were optimized, the assay was able to detect all four plant pathogens precisely and accurately with substantially higher sensitivity than enzyme-linked immunosorbent assay (ELISA) when spiked in buffer and in healthy watermelon leaf extract. The assay time of the microsphere immunoassay (1 hour) was much shorter than that of ELISA (4 hours). This system was also shown to be capable of detecting the pathogens in naturally infected plant samples and is a major advancement in plant pathogen detection. PMID:23638044
Natural toxin (for example mycotoxin and phycotoxin) contamination of food is of safety and economic concern, so much effort is devoted to the development of screening methods which enable the toxins to be continuously and widely monitored in food and feed. More generally speaking, rapid and non-instrumental assays for detection of a variety of food contaminants are generating ever-increasing scientific and technological interest because they enable high-throughput, economical, on-site monitoring of such contaminants. Among rapid methods for first-level screening of food contaminants, lateral-flow immunoassay (LFIA), also named immunochromatographic assay or immune-gold colloid immunoassay, has recently attracted scientific and industrial interest because of its attractive property of enabling very rapid, one-step, in-situ analysis. This review focuses on new aspects of the development and optimization of lateral-flow devices for mycotoxin and phycotoxin detection, including strategies for management of matrix interference and, particularly, for investigation of the improvements achieved by signal-enhancing strategies or by application of non-gold nanoparticle signal reporters. PMID:22543716
A high-Tc dc SQUID (superconducting quantum interference device) gradiometer was developed for magnetic immunoassays where magnetic nanoparticles are used as markers to detect biological reactions. The gradiometer was fabricated on a 5 × 10 mm2 SrTiO3 bicrystal substrate and has a gradiometer resolution of 2.1 pT cm-1 Hz-1/2. A magnetic signal was detected from a sample of 1 µl of Fe3O4 nanoparticles in a 40 mg ml-1 solution kept in a microcavity fabricated on Si wafers with Si3N4 membranes using MEMS (micro-electro-mechanical-systems) technology. It was found that volumes as small as 0.3 nl in principle would be detectable with our present device. This corresponds to a total number of particles of 2.2 × 107. The estimated average dipole moment per particle is 4.8 × 10-22 A m2. We are aiming at reading out immunoassays by detecting the Brownian relaxation of magnetic nanoparticles, and we also intend to integrate MEMS technology into our system.
Öisjöen, F.; Magnelind, P.; Kalabukhov, A.; Winkler, D.
...40(a), (b), and (e) subsequently may donate Source Plasma for use in the preparation of Hepatitis B Immune Globulin...due to HTLV, types I and II, may serve as a donor of Source Plasma; (5) A deferred donor who tests reactive for a...
This article presents a new model based on the loan-pushing model by Basu (1991) to show how a domestic debt crisis can occur in a low-income country following donor herding. The model focuses on the rational herding behaviour of donors due to payoff and information externalities. Although there are many theoretical models on herding behaviour, these models have not formally
Summary Antibiotic sterilized valves have been shown to function longer than those chemically sterilized; however, the reason remains obscure. Current hypotheses cite either retention of donor fibroblasts capable of repairing the grafted valve, or host fibroblast ingrowth into and onto the leaflet ground substance. A cryopreserved aortic homograft from a male donor was explanted from a female recipient after 10
Lorenzo Gonzalez-Lavin; Alan J. Spotnitz; James W. Mackenzie; Jiang Gu; Inder K. Gadi; Johnni Gullo; Charles Boyd; Debra Graf
As of September 15, 1987, 1,971 potential donors have signed consent forms and joined the Puget Sound Blood Center Bone Marrow Donor Program. Of these, 305 are family members of former bone marrow transplant patients, 274 were recruited from the pheresis ...
|This case study of Southern Illinois University was conducted to determine the types of volunteers needed for an annual fund drive. Based on a random sample of 138 alumni donors who completed questionnaires, a donor profile was developed. Analysis of questionnaire responses found that only 48% reported being involved with extracurricular
Continuous growth of the end stage renal disease population treated by dialysis, outpaces deceased donor kidneys available, lengthens the waiting time for a deceased donor transplant. As estimated by the United States Department of Health & Human Services: '17 people die each day waiting for transplants that can't take place because of the shortage of donated organs.' Strategies to expand the donor pool--public relations campaigns and Drivers' license designation--have been mainly unsuccessful. Although illegal in most nations, and viewed as unethical by professional medical organizations, the voluntary sale of purchased donor kidneys now accounts for thousands of black market transplants. The case for legalizing kidney purchase hinges on the key premise that individuals are entitled to control of their body parts even to the point of inducing risk of life. One approach to expanding the pool of kidney donors is to legalize payment of a fair market price of about 40,000 dollars to donors. Establishing a federal agency to manage marketing and purchase of donor kidneys in collaboration with the United Network for Organ Sharing might be financially self-sustaining as reduction in costs of dialysis balances the expense of payment to donors. PMID:16482095
Continuous growth of the end stage renal disease population treated by dialysis, outpaces deceased donor kidneys available, lengthens the waiting time for a deceased donor transplant. As estimated by the United States Department of Health & Human Services: 17 people die each day waiting for transplants that cant take place because of the shortage of donated organs. Strategies to expand
Personality factors related to organ donor card signing were explored in a sample of 94 students. Nondonors scored higher on Tempter's Death Anxiety Scale, Collett-Lester Fear of Death of Self, Death of Others, and Dying of Self subscales, and a scale of physical anxiety. Donors scored higher on a Likert scale reflecting acceptance of dying and, not surprisingly, on self-efficacy
The availability of cadaveric donor organs is insufficient for actual needs. The organ demand increases by 20% per year. Living donor transplant (LDT) may be a valid therapeutical alternative provided one uses proper criteria. LDT provides many advantages, like improved patient and organ survival, short waiting time, and the possibility to carefully plan the procedure. Potential risks include perioperative mortality
G Splendiani; S Cipriani; M Valeri; N Torlone; A Vega; T Tullio; S Condò; S Dominijanni; C. U Casciani
Clostridium difficile diarrhea is a common and severe infectious disease. Antibiotics, which are standard initial treatment, are less effective for treating refractory or recurrent infection. Fecal microbiota transplantation, where healthy donor stool is transplanted into a patient, is an alternative to antibiotic therapy that requires standardization for donors and patients. PMID:24012274
Owens, Casey; Broussard, Elizabeth; Surawicz, Christina
Donor leukocyte infusion (dli) has well-documented activity in cml, but the role of dli in other diseases is less well defined. to evaluate the strategy in multiple myeloma (mm) we evaluated 25 mm patients from 15 centers who were treated with dli. patients with persistent or recurrent disease after allogeneic bmt received dli from the original marrow donor (23 matched
M Salama; T Nevill; D Marcellus; P Parker; M Johnson; A Kirk; D Porter; S Giralt; JE Levine; W Drobyski; AJ Barrett; M Horowitz; RH Collins
Of all the problems foreseen in the pioneering days of organ transplantation, a shortage of donor organs, was not even remotely considered as a barrier to progress. Such has been the success of transplantation over the last two decades, organ shortage is now considered the major limitation.This chapter will concentrate on efforts to increase the donor potential.The development of Organ
|This article describes the experiences, feelings, and ideas of living kidney donors. Using a phenomenological, qualitative research approach, the authors interviewed 12 purposefully selected living kidney donors (eight men and four women), who were between four and 29 years since donation. Interviews were audiotaped, and transcribed verbatim, and
Brown, Judith Belle; Karley, Mary Lou; Boudville, Neil; Bullas, Ruth; Garg, Amit X.; Muirhead, Norman
To assist sibling bone marrow donors with the psychological and emotional distress that they may experience as donors, a sibling bone marrow donor program was developed at The Hospital for Sick Children. These donors feel overwhelming responsibility for their siblings' survival, which can lead to psychological distress. The donors are engaged in age-appropriate medical play and are encouraged to discuss
We present a general method for calculating the energy spectrum of donors confined in heterostructures with axial symmetry in the presence of magnetic and electric fields applied along the symmetry axis. The donors wave functions are chosen as a product of the Slater orbitals and an envelope function that is a solution of a one-dimensional differential equation, which we derive starting from Schrödingers variational principle. We calculate the energies of the ground and some excited states of a donor confined in multiple quantum wells and a nanowire superlattice as functions of the donor position, electric and magnetic fields for structures with different numbers and widths of the wells and the barriers. Our method could be applicable to a variety of complex quantum-confined semiconductor structures for which more rigorous approaches require extensive numerical calculations.
From April 15, 1965, to November 1993, 104 kidneys from living related donors (LRD) were transplanted to 104 patients with endstage chronic renal failure. The kidneys were taken from the patients' mother (n = 55), fathers (n = 21), sisters (n = 18), and brothers (n = 10). Analysis of the experience accumulated has demonstrated that the outcomes of kidney grafting from LRD are much better than those from cadaver donors. All the living donors were investigated in the late postoperative period. There were no negative influences on their health and social position. The residual was able to maintain the donors' homeostasis throughout their life. Thus, transplantation of the kidney from living related donors is the method of choice in patients with end-stage chronic renal failure. PMID:9376738
Markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were sought in serum samples from 2644 blood donors in 24 of Egypt's 26 governorates. Of the 2644 samples, 656 (24.8%) were shown to contain anti-HCV immunoglobulin G antibody by Abbott second generation enzyme immunoassays (EIA). Of 85 EIA-positive samples tested by recombinant immunoblot assay, 72 (85%) were positive. HCV seroprevalence in the governorates ranged from zero to 38%; 15 governorates (62%) had an HCV antibody prevalence greater than 20%, and 6 (25%) greater than 30%. Governorates with higher sero-prevalences were located in the central and north-eastern Nile river delta, and south of Cairo in the Nile river valley. Subjects from areas in and adjoining the Sinai peninsula, in the eastern and western desert, and in southernmost Egypt, had the lowest prevalence of HCV antibody. The large urban governorates of Cairo and Alexandria had antibody prevalences of 19% and 11%, respectively. A total of 39.4% subjects had evidence of HBV infection (and-HBV core antigen total antibody). HCV infections were detected more frequently in donors with markers for HBV infections than in uninfected subjects (36% versus 18%, P < 0.001). PMID:9231192
Arthur, R R; Hassan, N F; Abdallah, M Y; el-Sharkawy, M S; Saad, M D; Hackbart, B G; Imam, I Z
In two studies of fainting in Army blood donors: Data gathered on 172 donors showed no significant differences in intelligence or educational level between reactors and nonreactors. Data on 394 donors showed no significant differences between the two grou...
...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Plasma Â§ 640.31 Suitability of donors. (a) Whole blood donors shall meet the criteria for donor suitability prescribed...
We evaluated an automated chemiluminescence immunoassay (CLIA) developed for the measurement of urinary free deoxypyridinoline (DPD). The new DPD method by CLIA is based on the competition of DPD with particle-bound pyridinoline for a limited amount of monoclonal mouse anti-DPD antibody. Total imprecision (CV) was 3.2-9.0% at 30-270 nmol/L. Regression analysis of urinary DPD concentration (second morning-void) measured by CLIA (y) and enzyme immunoassay (EIA) for adult volunteers (n = 449) with and without bone disease revealed a best fit equation of: y = 1.08 +/- 0.03x - 1.15 +/- 0.98 nmol/L (r = 0.964, S(y/x) = 14 nmol/L). CLIA and EIA methods were correlated with HPLC measurement of urinary free DPD (r = 0.846 and 0.871, respectively). For healthy adults, the creatinine-normalized excretion of DPD (mean +/- SD) measured by CLIA for 61 men (4.1 +/- 1.2 micromol DPD/mol creatinine) and 76 premenopausal women (5.3 +/- 1.8 micromol DPD/mol creatinine) did not differ significantly (P >0.05) from DPD excretion measured by EIA, and both immunoassays showed a significant gender difference (P <0.001) in reference intervals. In a clinical trial, DPD excretion (micromol DPD/mol creatinine) measured by CLIA differed substantially from the reference population for 54 untreated pagetic (12.7 +/- 8.0 SD), 255 untreated osteoporotic (7.5 +/- 4.1), 21 osteomalacic (12.4 +/- 8.5), 17 primary hyperparathyroid (9.4 +/- 4.4), and 14 secondary hyperparathyroid (9.2 +/- 5.1) patients. Clinical sensitivities of the CLIA and EIA methods range from 38% to 80% in bone disorders and limit the use of the DPD measurement in disease detection. DPD excretion after pamidronate treatment in a subgroup of the pagetic patients fell dramatically as assessed by CLIA or EIA. We conclude that the automated CLIA method for DPD is a convenient and reliable method that may aid in the evaluation and management of bone disease and is applicable to high volume testing in the routine clinical laboratory. PMID:9761245
Rosano, T G; Peaston, R T; Bone, H G; Woitge, H W; Francis, R M; Seibel, M J
OBJECTIVE: A review of 100 living-liver donors was performed to evaluate the perisurgical complications of the procedure and thus to help quantify the risks to the donor. SUMMARY BACKGROUND DATA: Despite the advantages of living-donor liver transplantation (LDLT), the procedure has received criticism for the risk it imposes on healthy persons. A paucity of data exists regarding the complications and relative safety of the procedure. METHODS: One hundred LDLTs performed between November 1989 and November 1996 were reviewed. Donor data were obtained by chart review, anesthesia records, and the computerized hospital data base. Patient variables were compared by Fisher's exact test and the Student's t test. RESULTS: There were 57 women and 43 men with a median age of 29. Donors were divided into two groups: group A (first 50 donors), and group B (last 50 donors). There were 91 left lateral segments and 9 left lobes. There were no deaths. Fourteen major complications occurred in 13 patients; 9 occurred in group A and 5 in group B. Biliary complications consisted of five bile duct injuries (group A = 4, group B = 1) and two cut edge bile leaks. Complications were more common in left lobe resections (55%) than in left lateral segment grafts (10%). Minor complications occurred in 20% of patients. A significant reduction in overall complications (major and minor) was observed between the groups (group A, n = 24 [45%] vs. group B, n = 10 [20%]). In addition, surgical time and hospital stay were both significantly reduced. CONCLUSIONS: Although the procedure is safe, many LDLT donors have a perisurgical complication. Surgical experience and technical modifications have resulted in a significant reduction in these complications, however. To minimize the risks for these healthy donors, LDLT should be performed at institutions with extensive experience.
Grewal, H P; Thistlewaite, J R; Loss, G E; Fisher, J S; Cronin, D C; Siegel, C T; Newell, K A; Bruce, D S; Woodle, E S; Brady, L; Kelly, S; Boone, P; Oswald, K; Millis, J M
The application of quantum dots (QDs) as labels in immunoassay microarrays for the multiplex detection of 3- phenoxybenzoic acid (PBA) and atrazine-mercapturate (AM) has been demonstrated. PBA and AM are biomarkers of exposure to the pyrethroid insecticides and to the herbicide atrazine, respectively. Microarrays were fabricated by microcontact printing of the coating antigens in line patterns onto glass substrates. Competitive immunoassays were successfully performed using quantum dots (QD560 and QD620) as reporters. The multiplexed immunoassays were characterized by fluorescence microscopy and SEM. The application of QD fluorophores facilitates multiplex assays and therefore can contribute to enhanced throughput in biomonitoring.
Nichkova, Mikaela; Dosev, Dosi; Davies, Alexander E.; Gee, Shirley J.; Kennedy, Ian M.; Hammock, Bruce D.
In this study a disperse dye immunoassay method was standardized and evaluated for detection of antibodies against Neospora caninum in cattle. Sera from 150 cattle with a recent history of abortion were collected and tested by commercial ELISA kit and a standardized in-house dye immunoassay system. The positivity rate for the sera used in this study was 34.6% for the disperse dye immunoassay (DDIA) compared to 32% obtained by ELISA kit. This study showed no significant difference between DDIA and ELISA. The results indicated that the DDIA provide an economic, simple, rapid and robust test for detection of N. caninum infection in cattle.
Selahi, Fatemeh; Hosseini, Mohammad Hossein; Mansourian, Maryam; Tahamtan, Yahya
In this study a disperse dye immunoassay method was standardized and evaluated for detection of antibodies against Neospora caninum in cattle. Sera from 150 cattle with a recent history of abortion were collected and tested by commercial ELISA kit and a standardized in-house dye immunoassay system. The positivity rate for the sera used in this study was 34.6% for the disperse dye immunoassay (DDIA) compared to 32% obtained by ELISA kit. This study showed no significant difference between DDIA and ELISA. The results indicated that the DDIA provide an economic, simple, rapid and robust test for detection of N. caninum infection in cattle. PMID:23467930
Aboriginals experience high rates of end-stage renal disease (ESRD) and are less likely to receive a kidney transplant from a living donor. We hypothesized that higher rates of hypertension and diabetes in Aboriginal communities would result in fewer potential living donors coming forward and more exclusions for medical reasons. We performed a retrospective study to examine the frequency of potential donor presentation and the reasons for donor exclusion among Aboriginal and Caucasian wait-listed ESRD patients at our center. Three hundred and eighty-five wait-listed patients were studied, including 174 Aboriginals and 211 Caucasians. Time on the waiting list was similar between groups. A similar proportion of Aboriginals and Caucasians had at least one potential donor (40% vs. 46%), and the rate of donor exclusion for medical reasons was also similar (23% vs. 21%). Potential donors to Aboriginals were more likely to be excluded for non-medical reasons (50% vs. 30%; p < 0.0001), of which 96% were because of loss of contact. Waitlisted Aboriginal ESRD patients appear just as likely as Caucasians to have potential living donors initiate evaluation and have a similar rate of donor exclusion because of medical reasons. Further work is required to identify why donors to Aboriginals are more likely to withdraw from the evaluation process. PMID:21919960
Rarely have donor conceived offspring been studied. Recently, it has become more common for parents to disclose the nature of conception to their offspring. This new development raises questions about the donor's place in the offspring's life and identity. Using surveys collected by the Donor Sibling Registry, the largest U.S. web-based registry, during a 15 week period from October 2009 to January 2010, we found that donor offspring view the donor as a whole person, rather than as simple genetic material (he can know you; he has looks; he can teach you about yourself); they also believe that the donor should act on his humanity (he should know about you and not remain an anonymous genetic contributor). Other new issues that emerge from this research include the findings that offspring may want to control the decision about contacting their sperm donor in order to facilitate a bond between themselves and the donor that is separate from their relationship with their parents. They also wish to assure their parents that their natal families are primary and will not be disrupted. We discuss how the age at which offspring learned about their donor conception and their current age each make a difference in their responses to what they want from contact with their donor. Family form (heterosexual two-parent families and lesbian two-parent families) also affects donor terminology. The role of the genetic father is reconsidered in both types of families. Donor conceived offspring raised in heterosexual families discover that their natal father no longer carries biological information and he is relegated to being "only" a social father. Offspring raised by lesbian couples experience a dissipation of the family narrative that they have no father. The donor, an imagined father, offers clues to the offspring's personal identity. The natal family is no longer the sole keeper of identity or ancestry. PMID:23608094
A novel line immunoassay for the multiparametric detection of 11 antiganglioside autoantibodies (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GT1a, GT1b, and GQ1b) was evaluated by comparing the reactivities in sera of 77 patients with suspected or definite autoimmune peripheral neuropathies (PNP), 60 blood donors, and 30 systemic lupus erythematodes (SLE) patients. At least one antiganglioside autoantibody was detectable in 97.4% of the patients with neuropathies compared to 12.2% in the control group. A broad spectrum of reactivities with more than two antiganglioside autoantibodies including all tested gangliosides except GD2 and GT1b was found in nearly one-third of the patients with neuropathies whereas in the control group autoantibody profiles with more than two reactivities were observed in two SLE patients only. For the first time anti-GM4 IgG and IgM antibodies were shown in PNP including Guillain-Barré syndrome (GBS), Miller-Fisher syndrome (MFS), and multifocal motor neuropathy (MMN). Different autoantibody profiles detectable by this multiparametric assay may help to diagnose different entities within the growing spectrum of autoimmune PNP. PMID:17785314
Objective: This study aimed to establish chemiluminescent immunoassay (CLIA) for quantitative determination of theophylline levels in human serum. Methods: To measure the concentration of theophylline (n=122) and evaluate the assay. Results: The linear range of the CLIA method was 0.51~40 mg/L (Y=1.02X+0.44, r=0.995). The intra and inter CV (coefficient variance) of CLIA were 3.20% and 3.57%, respectively. The average recovery rate was 102.3%. This method was free from interference by brilirubin (<200 ?mol/L), hemoglobin (<10 g/L), and triglycerides (<15 mmol/L). Conclusion: This method is simple, convenient and precise for clinical pharmacokinetics study of theophylline.
The use of gold nanoparticles (AuNPs) as labeling carriers in combination with the enzymatic activity of the horseradish peroxidase (HRP) in order to achieve an improved optical lateral flow immunoassay (LFIA) performance is presented here. Briefly in a LFIA with an immune-sandwich format AuNPs are functionalized with a detection antibody already modified with HRP, obtaining an 'enhanced' label. Two different detection strategies have been tested: the first one following just the red color of the AuNPs and the second one using a substrate for the HRP (3 different substrates are evaluated), which produces a darker color that enhances the intensity of the previous red color of the unmodified AuNPs. In such very simple way it is gaining sensitivity (up to 1 order of magnitude) without losing the simplicity of the LFIA format, opening the way to other LFIA applications including their on-demand performance tuning according to the analytical scenario. PMID:22795532
Parolo, Claudio; de la Escosura-Muñiz, Alfredo; Merkoçi, Arben
The Miniaturized Array for Solar System Exploration (MASSE) will use a microarray of antibody assays to search for biomarkers in extraterrestrial environments. We have now used enzyme linked immunosorbent assay (ELISA) to demonstrate the feasibility of immuno-detection of biomarkers in terrestrial soil, JSC-1 Mars regolith simulant, and terrestrial polar permafrost as analogues f ro extraterrestrial materials. We have also demonstrated that the technique works at microgravity and Martian gravity. Studies are now underway to test immunoassay techniques and antibody arrays at varying pressures and temperatures. It is expected that these studies will lead to a flight ready biomarker detection instrument that will be landed and operated on the Martian surface in 2009.
McKay, D.; Steele, A.; Warmflash, D.; Maule, J.; Lynch, K.
Magnetic immunoassays utilizing magnetic markers and a high -Tc SQUID have been performed. The marker was designed so as to generate remanence, and its remanence field was measured with the SQUID. The SQUID system was developed so as to measure 12 samples in one measurement sequence. We first conducted a detection of antigen called human IgE using IgE standard solution, and showed the detection of IgE down to 2 attomol. The binding process between IgE and the marker could be semi-quantitatively explained with the Langmuir-type adsorption model. We also measured IgE in human serums, and demonstrated the usefulness of the present method for practical diagnosis.
We have developed an ultrasensitive indirect competitive enzyme-linked immunosorbent assay for the determination of tartrazine. Two carboxylated analogues of tartrazine with different spacer lengths, and one derivative from commercial tartrazine after a little chemical modification, were synthesized as haptens in order to produce antibodies specific to tartrazine. The effect of sulfonic acid groups on the hapten structure of tartrazine was also studied carefully for the first time. A most specific monoclonal antibody against tartrazine was created and exhibited an IC50 value of 0.105 ng/mL and a limit of detection of 0.014 ng/mL, with no cross-reactivity to other structurally-related pigments. The established immunoassay was applied to the determination of tartrazine in fortified samples of orange juice and in real positive samples of carbonated beverages. PMID:23799494
An immunoassay performed on a portable microfluidic device was evaluated for the determination of urinary albumin. An increase in absorbance at 500 nm resulting from immunoagglutination was monitored directly on the poly(dimethylsiloxane) (PDMS) microchip using a portable miniature fibre-optic spectrometer. A calibration curve was linear up to 10 mg L1 (r2 = 0.993), with a detection limit of 0.81 mg L1 (S/N = 3). The proposed system showed good precision, with relative standard deviations (RSDs) of 5.1%, when evaluated with 10 mg L1 albumin (n = 10). Determination of urinary albumin with the proposed system gave results highly similar to those determined by the conventional spectrophotometric method using immunoturbidimetric detection (r2 = 0.995; n = 15).
Fluorescence correlation spectroscopy (FCS) is a powerful technique for measuring physicochemical properties, such as concentration and diffusion constant, of bio-molecules in complex mixtures. Although, as such, FCS is well suited for development of homogeneous immunoassays, a major obstacle lies in the relatively high molecular weight of antibodies. This is because in FCS discrimination between unbound fluorescently-labelled antibodies and the same antibodies bound to immune complexes is based on the difference of their respective diffusion coefficients. To overcome this limitation we here propose to use a fluorescently-labelled tag which has two crucial properties: (a) its molecular weight is significantly lower than that of an antibody and (b) it is capable to discriminate between free antibodies and immune complexes. We have evaluated the feasibility of this approach in a model system consisting of mouse monoclonal IgG directed against the Lewis X antigen, and Protein A as a low molecular weight tag. PMID:14711501
Mayboroda, Oleg A; van Remoortere, Alexandra; Tanke, Hans J; Hokke, Cornelis H; Deelder, André M
The fraudulent addition of hazelnut oil to more expensive olive oil not only causes economical loss but may also result in problems for allergic individuals as they may inadvertently be exposed to potentially allergenic hazelnut proteins. To improve consumer safety, a rapid and sensitive direct biosensor immunoassay, based on a highly specific monoclonal antibody, was developed to detect the presence of hazelnut proteins in olive oils. The sample preparation was easy (extraction with buffer); the assay time was fast (4.5 min only) and the limit of detection was low (0.08 microg/g of hazelnut proteins in olive oil). Recoveries obtained with an olive oil mixed with different amounts of a hazelnut protein containing hazelnut oil varied between 93% and 109%. PMID:19263041
Bremer, Maria G E G; Smits, Nathalie G E; Haasnoot, Willem
We have developed an ultrasensitive indirect competitive enzyme-linked immunosorbent assay for the determination of tartrazine. Two carboxylated analogues of tartrazine with different spacer lengths, and one derivative from commercial tartrazine after a little chemical modification, were synthesized as haptens in order to produce antibodies specific to tartrazine. The effect of sulfonic acid groups on the hapten structure of tartrazine was also studied carefully for the first time. A most specific monoclonal antibody against tartrazine was created and exhibited an IC50 value of 0.105 ng/mL and a limit of detection of 0.014 ng/mL, with no cross-reactivity to other structurally-related pigments. The established immunoassay was applied to the determination of tartrazine in fortified samples of orange juice and in real positive samples of carbonated beverages.
This article outlines psychosocial and ethical issues to be considered when evaluating potential living organ donors. Six types of living donors are described: genetically related, emotionally related, \\
Background Gold nanoparticles (AuNPs) scatter light intensely at or near their surface plasmon wavelength region. Using AuNPs coupled with dynamic light scattering (DLS) detection, we developed a facile nanoparticle immunoassay for serum protein biomarker detection and analysis. A serum sample was first mixed with a citrate-protected AuNP solution. Proteins from the serum were adsorbed to the AuNPs to form a protein corona on the nanoparticle surface. An antibody solution was then added to the assay solution to analyze the target proteins of interest that are present in the protein corona. The protein corona formation and the subsequent binding of antibody to the target proteins in the protein corona were detected by DLS. Results Using this simple assay, we discovered multiple molecular aberrations associated with prostate cancer from both mice and human blood serum samples. From the mice serum study, we observed difference in the size of the protein corona and mouse IgG level between different mice groups (i.e., mice with aggressive or less aggressive prostate cancer, and normal healthy controls). Furthermore, it was found from both the mice model and the human serum sample study that the level of vascular endothelial growth factor (VEGF, a protein that is associated with tumor angiogenesis) adsorbed to the AuNPs is decreased in cancer samples compared to non-cancerous or less malignant cancer samples. Conclusion The molecular aberrations observed from this study may become new biomarkers for prostate cancer detection. The nanoparticle immunoassay reported here can be used as a convenient and general tool to screen and analyze serum proteins and to discover new biomarkers associated with cancer and other human diseases.
Today, serum antimullerian hormone (AMH) is considered as an interesting marker of fertility potential in women to determine follicular status and in men to evaluate testicular function. We study analytical and clinical characteristics of two AMH commercialized immunoassays: Immunotech and DSL methods. The detection limits (close to 0.13 ng/mL), functional sensitivities (close to 0.30 ng/mL) are equivalent, and imprecision results are acceptable for entirely manual assays. The Immunotech method is linear within the calibration range (up to 21 ng/mL) and the DSL method presents a lack of linearity making it accurate only up to 11 ng/mL (and not up to 14 ng/mL as it is indicated by the manufacturer). The two methods allow to measure human AMH, don't cross react with TGF-beta superfamily proteins and the DSL immunoassay recognize mouse (25%), rat (68%) and calf (100%) AMH. The comparison between the two methods (from 0.3 to 200 ng/mL) shows a good correlation (r = 0.979) with not statistically different results (p = 0.31). From a clinical point of view, the two methods allow the evaluation of follicular status in normo-ovulatory women and in women with polycystic ovary syndrome. Results are in agreement with studies showing that AMH serum concentration is strongly correlated with the number of antral follicles. In conclusion, the Immunotech method seems to be more efficient than the DSL method even if the two methods are suitable for clinical applications needing AMH measurements. PMID:18957343
Taieb, J; Belville, C; Coussieu, C; Guibourdenche, J; Picard, J-Y; Di clemente, N
Discusses why volatile markets and new donor expectations make now a good time to rework payout rates and gift agreements to bolster financial and strategic performance. Suggests seven options for action. (EV)
...Section 35.64 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Contributions for the Benefit of Patients Â§ 35.64 Donors....
Text Version... methods. The blood establishment should choose the method that works best within its donor screening procedures. This ... More results from www.fda.gov/downloads/biologicsbloodvaccines/guidancecomplianceregulatoryinformation
Text VersionPage 1. Human Donor Milk: The Canadian Experience ... Page 4. The Canadian Paediatric Society: ... Fat (50% of energy in human milk) Minimal ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials
Credit project design largely determines credit project performance. Criticisms of the performance of donor-supported credit projects often cite problems which can be traced to project design flaws. The principal modifications required for a reorientation...
IntroductionWe evaluated the safety and efficacy of ex vivo ureteroscopy (ExURS) and extracorporeal shock wave lithotripsy (ESWL) as means of rendering a donated kidney stone-free in living related and deceased donor renal transplantation.
A. Trivedi; S. Patel; A. Devra; J. Rizvi; R. Goel; P. Modi
... Donor Information System, Version 1.0. Applicant: Community Bio-Resources, Inc., Hoover, AL. 510(k) number: BK970007. ... More results from www.fda.gov/biologicsbloodvaccines/bloodbloodproducts/approvedproducts
We discuss the possibility of performing single spin measurements in Si-based quantum computers through electric field control of electrons bound to double donors near a barrier interface. In particular, we investigate the feasibility of shuttling donor-bound electrons between the double donor impurity in the bulk and the Si/SiO2 interface by tuning an external electric field. We find that both the required electric fields and the tunneling times involved are probably too large for practical implementations. We also investigate operations with double donors in their first excited state: In this case ionization fields are smaller and tunneling times are faster, as required in spin-to-charge conversion measurements. This work is supported by LPS and NSA.  M.J. Calderon, B. Koiller, and S. Das Sarma, cond- mat/0610089.
Calderon, Maria J.; Koiller, Belita; Das Sarma, Sankar
Text Version... 510(k) Statement/Statement of Device Safety and Effectiveness BioLife Plasma Services LP Donor Information System - Version 3.3 ... More results from www.fda.gov/downloads/biologicsbloodvaccines/bloodbloodproducts
... screening test, as described in section V. (§ 1271.80(c)). Current FDA-licensed, cleared or approved donor screening tests for use in testing HCT/P ... More results from www.fda.gov/biologicsbloodvaccines/safetyavailability/tissuesafety
less than 30% of the patients in North America have an HLA-matched sibling and 3-5% have a one HLA-locus mismatched relative, for most patients in need of an allogeneic marrow transplant the only chance of finding a suitable donor is through the identification of an HLA-compatible unrelated volunteer. Three accomplishments have allowed unrelated donor transplants to become feasible and successful:
Therapeutic insemination with donor sperm (TDI) is an established and highly effective technique in the treatment of uncorrectable\\u000a semen deficiencies, inherited genetic disorders, and with single or homosexual women who desire pregnancy. The first documented\\u000a TDI case was performed as early as 1884 (1), but it is speculated that donor semen has been used worldwide for centuries (2). In the
This manuscript is a survey of the halachic attitudes toward organ transplant procedures from a living donor which can be defined as life-saving procedures for the recipient or at least life-prolonging procedures. Three fundamental problems concerning the halachic aspects of such transplantation are discussed in detail: the danger to the donor, donation under coercion, and the sale of organs and tissues. The terms halacha and Jewish law are defined in the introduction.
Objectives. To review the selection criteria and perioperative morbidity in patients undergoing living-related donor nephrectomy.Methods. Retrospective chart review.Results. Six hundred eighty-one patients underwent living donor nephrectomy during a 20-year period without any mortality. The postoperative morbidity included pneumothorax requiring a chest tube in 7%, urinary tract infection in 5%, wound infection in 4%, and need for blood replacement in 0.3%
Mark J. Waples; Folkert O. Belzer; David T. Uehling
This manuscript is a survey of the halachic attitudes toward organ transplant procedures from a living donor which can be defined as life-saving procedures for the recipient or at least life-prolonging procedures. Three fundamental problems concerning the halachic aspects of such transplantation are discussed in detail: the danger to the donor, donation under coercion, and the sale of organs and tissues. The terms "halacha" and "Jewish law" are defined in the introduction. PMID:23908800
The current shortage of donor organs is a well-recognized global phenomenon. The goal of contemporary transplant practice is to optimize and expand the organ donor pool. Despite biologic and technologic advancements, the single most important limitation remains underutilization and non-recovery of potential organs. We report the use of a donor cardiac organ from a 5-year-old child who had undergone recent
Jonathan J Drummond-Webb; Michael L Schmitz; Charles E Johnson; Elizabeth A Frazier
Objective: The use of non-heart-beating (NHB) lung donors has been propagated as an alternative besides heart-beating (HB) lung donors to overcome organ shortage. We evaluated the effectiveness of NHB lung transplantation Methods: The donor and recipient data of all 35 NHB category III lung transplantations (LTx) between January 2005 and December 2009 were reviewed. For comparison, we collected recipient and
Caroline Van De Wauwer; Erik A. M. Verschuuren; Wim van der Bij; George D. Nossent; Michiel E. Erasmus
A compact photonic immunoassay biosensor that can simultaneously sense multiple analytes has been implemented. NSOM results indicate 8% modulation of the local evanescent field due to an 18 nm biological adlayer on the waveguide's surface.
Kevin L. Lear; Guangwei Yuan; Matthew D. Stephens; Xinya He; Robert Pownall; Rongjin Yan; Phil Nikkel; Charles S. Henry; Thomas W. Chen; David S. Dandy
Two representative immunoassays for measuring thyroxine and beta-subunit of human chorionic gonadotrophin in serum, using the Opus immunoassay analyzer, were evaluated by comparing them to the reference RIA for T4 and beta-HCG enzyme immunoassay. Both assays were superior in accuracy and precision than the reference methods and exhibited good linearity throughout the concentration range needed for discriminating abnormally low and elevated concentrations from the established reference ranges of thyroxine and beta-human chorionic gonadotrophin in serum. Correlation between the results of the Opus immunoassays and the reference assays for T4 and beta-HCG was very good with correlation coefficients of 0.92 and 0.98, respectively. PMID:8951607
The advantages of enzyme-immunoassay (EIA) over radioactive assay techniques are mainly convenience in use, in that the labelled immunoreagents are stable for long periods, and the precautions and disposal procedures required for radioisotopes are unneces...
Lateral flow (immuno)assays are currently used for qualitative, semiquantitative and to some extent quantitative monitoring in resource-poor or non-laboratory environments. Applications include tests on pathogens, drugs, hormones and metabolites in biomedical, phytosanitary, veterinary, feed/food and environmental settings. We describe principles of current formats, applications, limitations and perspectives for quantitative monitoring. We illustrate the potentials and limitations of analysis with lateral flow (immuno)assays using a literature survey and a SWOT analysis (acronym for "strengths, weaknesses, opportunities, threats"). Articles referred to in this survey were searched for on MEDLINE, Scopus and in references of reviewed papers. Search terms included "immunochromatography", "sol particle immunoassay", "lateral flow immunoassay" and "dipstick assay". PMID:18696055
Posthuma-Trumpie, Geertruida A; Korf, Jakob; van Amerongen, Aart
Several endemic mycoses cause cross-reactions in the Histoplasma antigen enzyme immunoassay. Herein, a positive Histoplasma antigen result has been recognized in a patient with sporotrichosis. PMID:21813658
This invention pertains to improving stability of immunoassays by using a more stable component. More specifically, this invention pertains to the use of a stable source of hydrogen peroxide in a peroxidase enzyme assay wherein the source releases hydroge...
To detect a biomarker for small cell lung carcinoma, neuron specific enolase (NSE), a sensitive and specific chemiluminescence enzyme immunoassay was developed. Fluorescein isothiocyanate (FITC) labeled NSE capture antibody connected with NSE and alkaline phosphatase (ALP) labeled NSE detection antibody in a sandwich-type detection manner. This immune complex was further reacted with anti-FITC coated magnetic beads. In a magnetic field, the complex was enriched, and the sensitivity was thus enhanced. The limit of detection (LOD) of this method was <0.2 ng mL(-1). The proposed immunoassay was highly selective, and not interfered by hook effect. The recovery was >83.0% and the coefficient of variation was <10.0%. Human sera from 120 patients were tested with the presented and traditional chemiluminescence enzyme immunoassay. An excellent linear relationship was obtained between two techniques. Overall, this immunoassay offers a promising alternative for NSE detection than traditional clinical examinations. PMID:22444542
Double cord blood transplantation (DCBT) with two matched or partially matched cord blood units has been implemented successfully to circumvent the limitations of graft cell dose associated with single CBT. After DCBT, sustained haematopoiesis is derived almost exclusively from only one of the donated units. None the less, we previously observed two of six evaluable DCBT patients still having mixed donordonor chimerism at 28 and 45 months post-transplantation, respectively. In the present study we utilize flow cytometry techniques to perform the first thorough analysis of phenotype and functionality of cord blood units in patients with mixed donordonor chimerism. Our results suggest that the two stable cord blood units are different phenotypically and functionally: one unit shows more naive T cells, lower T cell cytokine production and higher frequencies of natural killer cells, the other shows higher frequencies of well-differentiated and functional lymphocytes. Additionally, in comparison with control patients having a single prevailing cord blood unit, the patients with donordonor chimerism exhibit less overall T cell cytokine production and a smaller fraction of memory T cells. Furthermore, our results indicate that human leucocyte antigen-C match of donor units may partly explain the development of a donordonor mixed chimerism.
Gertow, J; Berglund, S; Okas, M; Uzunel, M; Berg, L; Karre, K; Mattsson, J; Uhlin, M
A sensitive and reproducible high-performance liquid chromatographic (HPLC) method is described for assay of gentamicin in serum using ultrafiltration of serum samples and pre-column derivatization with o-phthalaldehyde. The procedure was compared with a bioassay and an enzyme immunoassay. Coefficients of correlation were 0.98 for HPLC vs. bioassay and 0.97 for HPLC vs. immunoassay. The between-day imprecision (n=5) was estimated from
Sol-gel-derived mesoporous biomaterials were used for the first time in the flow-injection fluorescence immunoassay system. Anti-gentamicin antibody was immobilized in a mesoporous sol-gel material using tetramethoxysilane as a precursor and poly(ethylene glycol) as a template. The sol-gel glass was used to develop an immunoaffinity column for the flow-injection immunoassay of gentamicin. Little unspecific adsorption of gentamicin on the sol-gel and
In contrast to the type of two-sample measurement used in conventional nephelometric immunoassay, a methodology to achieve a one-sample nephelometric immunoassay is developed in this work. Magnetic nanoparticles instead of latex particles are used as scattering centers. The experimental results show that the sensitivity of assaying avidin or c-reactive protein increased about three times under the action of the magnetic
S. Y. Yang; R. M. Wu; Z. F. Jian; H. E. Horng; Chin-Yih Hong; H. C. Yang
The effects of size and porosity of particles on magnetic immunoassay in a thin channel were studied. Experimental parameters were investigated and compared using a model immunoassay complex of carcinoembryonic antigen (CEA)\\/anti-CEA. The rate constant for the affinity reaction between functional particles increased as the size of magnetic nanoparticles (80080nm) decreased. The affinity reaction between functional particles had no significant
H. Y. Tsai; Y. C. Hsieh; Y. M. Su; J. R. Chan; Y. C. Chang; C. Bor Fuh
Objectives: To perform an analytical evaluation of the new electrochemiluminescent immunoassays (ECLIA) for TSH, FT4, and T3 in the Elecsys 2010 immunoassay system. To assess the clinical classification of patients under suspicion of thyroid disease based on these laboratory assays.Materials and methods: The analytical evaluation included the performance of minimum detectable concentrations, within-assay and inter-assay precision for the three analytes,
Marta Sánchez-Carbayo; Montserrat Mauri; Rocío Alfayate; Carmen Miralles; Federico Soria
Objectives. To determine whether laparoscopic living donor nephrectomy is safe and efficacious in markedly obese renal donors.Methods. From 1996 to 1999, 431 laparoscopic living donor nephrectomies were performed. The markedly obese group consisted of 41 patients with a body mass index (BMI) greater than 35. Forty-one controls with a BMI less than 30 were matched to the obese donors by
Stephen C Jacobs; Eugene Cho; Brian J Dunkin; Stephen T Bartlett; John L Flowers; Bruce Jarrell
Due to organ shortage and difficulties for availability of cadaveric donors, living donor transplantation is an important choice for having allograft. Live donor surgery is elective and easier to organize prior to starting dialysis thereby permitting preemptive transplantation as compared to cadaveric transplantation. Because of superior results with living kidney transplantation, efforts including the usage of Medically complex living donors are made to increase the availability of organs for donation. The term Complex living donor is probably preferred for all suboptimal donors where decision-making is a problem due to lack of sound medical data or consensus guidelines. Donors with advanced age, obesity, asymptomatic microhematuria, proteinuria, hypertension, renal stone disease, history of malignancy and with chronic viral infections consist of this complex living donors. This medical complex living donors requires careful evaluation for future renal risk. In this review we would like to present the major issues in the evaluation process of medically complex living kidney donor.
Summary Background and objectives Living donor paired exchange programs assume that kidneys from living donors are of comparable quality and anticipated longevity. This study determined actual allograft t1/2 within different recipient age groups (10-year increments) as a function of donor age (5-year increments), and juxtaposed these results against the probabilities of deceased donor transplantation, and exclusion from transplantation (death or removal from the wait-list). Design, setting, participants, & measurements Data from the US Renal Data System (transplant dates 19882003 with follow-up through September 2007) were used to determine allograft t1/2, whereas data from patients on the United Network for Organ Sharing waiting list between 2003 and 2005 (with follow-up through February 2010) were used to determine wait-list outcomes. Results With the exception of recipients aged 1839 years, who had the best outcomes with donors aged 1839 years, living donor age between 18 and 64 years had minimal effect on allograft t1/2 (difference of 12 years with no graded association). The probability of deceased donor transplantation after 3 years of wait-listing ranged from 21% to 66% by blood type and level of sensitization, whereas the probability of being excluded from transplantation ranged from 6% to 27% by age, race, and primary renal disease. Conclusions With the exception of recipients aged 1839 years, living donor age between 18 and 64 years has minimal effect on allograft survival.
Chang, Peter; Gill, Jagbir; Dong, James; Rose, Caren; Yan, Howard; Landsberg, David; Cole, Edward H.
The risk of cytomegalovirus (CMV) infection is higher after HLA-matched unrelated donor (URD) than after HLA-matched related donor (MRD) nonmyeloablative hematopoietic cell transplantation (HCT). We therefore investigated factors affecting immune recovery in 94 patients given HCT from MRDs (n = 51) and URDs (n = 43) after 2-Gy total body irradiation with or without fludarabine and postgrafting immunosuppression with mycophenolate
Frédéric Baron; Barry Storer; Michael B. Maris; Jan Storek; Fanny Piette; Monja Metcalf; Kristen White; Brenda M. Sandmaier; David G. Maloney; Rainer Storb; Michael Boeckh
The Welsh Bone Marrow Donor Registry (WBMDR) is in its 11th year of operation and its 4th year as an International Hub participating in Bone Marrow Donors Worldwide. It is operated by the Welsh Regional Tissue Typing Laboratory which is accredited by Clinical Pathology Accreditation (UK) Ltd, and the European Federation for Immunogenetics and, together with the Welsh Blood Service,
This descriptive study assessed the experiences of unrelated bone marrow donation in 27 Chinese donors and compared their mood states with a random sample of 78 Chinese adult non-donors using four scales. The donors demonstrated better mood states in terms of anger- hostility and fatigue compared to non-donors. However, their self-esteem was low (similarly to the non-donors), they did not
BACKGROUND New regulatory requirements for donor eligibility challenge blood centers to recruit and retain enough donors. This study evaluated correlations between overall satisfaction with the donation process and donor demographics and the effect of both on a donors intent to return. STUDY DESIGN AND METHODS An anonymous, self-administered questionnaire was given to donors at multiple sites of one blood center over a 3-week period. First-time and repeat donors were asked questions on demographic characteristics, satisfaction with the current donation process, motivation for current and future donations, and intent to return. RESULTS More than 75 percent of donors rated the overall donation process at 9 or 10 on a scale of 10 (mean, 9.19; standard deviation, 1.09), with female, high schooleducated, and first-time donors giving higher satisfaction ratings than male, college-educated, and repeat donors, respectively (all p < 0.001). Donor satisfaction was correlated with intent to return for another donation (p = 0.002). For the current donation, donors rated altruistic motivations most highly. Medical testing was the most highly rated incentive for future donations, followed by frequent donor programs and convenient donation times and locations; preferences varied by demographic subgroup. CONCLUSIONS Blood donor satisfaction varies among demographic and donation history subgroups and is positively correlated with the intent to return for future donation. Although the primary motivation among all donors was altruism, incentives to future donation may need to be tailored according to demographic subgroups.
Nguyen, Dorothy D.; DeVita, Deborah A.; Hirschler, Nora V.; Murphy, Edward L.
Background Plasma tumor biomarkers are widely used clinically for monitoring response to therapy and detecting cancer recurrence. However, only a limited number of them have been effectively used for the early detection of cancer. Objective To review plasma tumor markers used clinically for the early detection of cancer and to provide expert opinion about future directions. Methods Literature review, as well as our expert opinion, of plasma tumor markers that have been widely accepted for the early detection of cancer. Results In the United States, only prostate specific antigen (PSA), cancer antigen 125 (CA125), and alpha-fetoprotein (AFP) have been clinically used for the early detection of prostate, ovarian, and liver cancers, respectively. Both analytical and clinical issues related to the use of these three markers were discussed. Conclusion Few plasma tumor markers have been used effectively for the early detection of cancer, mainly due to their limited sensitivity and/or specificity. Multiple approaches have been developed to improve the clinical performance of tumor markers for the early detection of cancer. Metrological traceability and antibody specificity are important issues to ensure comparability of immunoassays for the measurement of plasma tumor markers.
Rapid and multiplexed measurement is vital in the detection of food-borne pathogens. While highly specific and sensitive, traditional immunochemical assays such as enzyme-linked immunosorbent assays (ELISAs) often require expensive read-out equipment (e.g. fluorescent labels) and lack the capability of multiplex detection. By combining the superior specificity of immunoassays with the sensitivity and simplicity of magnetic detection, we have developed a novel multiplex magnetic nanotag-based detection platform for mycotoxins that functions on a sub-picomolar concentration level. Unlike fluorescent labels, magnetic nanotags (MNTs) can be detected with inexpensive giant magnetoresistive (GMR) sensors such as spin-valve sensors. In the system presented here, each spin-valve sensor has an active area of 90 × 90 µm2, arranged in an 8×8 array. Sample is added to the antibody-immobilized sensor array prior to the addition of the biotinylated detection antibody. The sensor response is recorded in real time upon the addition of streptavidin-linked MNTs on the chip. Here we demonstrate the simultaneous detection of multiple mycotoxins (aflatoxins B1, zearalenone and HT-2) and show that a detection limit of 50 pg/mL can be achieved.
Mak, Andy C.; Osterfeld, Sebastian J.; Yu, Heng; Wang, Shan X.; Davis, Ronald W.; Jejelowo, Olufisayo A.; Pourmand, Nader
At present, point-of-care (POC) diagnostics typically provide a binary indication of health status (e.g., home pregnancy test strip). Before anticipatory use of diagnostics for assessment of complex diseases becomes widespread, development of sophisticated bioassays capable of quantitatively measuring disease biomarkers is necessary. Successful translation of new bioassays into clinical settings demands the ability to monitor both the onset and progression of disease. Here we report on a clinical POC diagnostic that enables rapid quantitation of an oral disease biomarker in human saliva by using a monolithic disposable cartridge designed to operate in a compact analytical instrument. Our microfluidic method facilitates hands-free saliva analysis by integrating sample pretreatment (filtering, enrichment, mixing) with electrophoretic immunoassays to quickly measure analyte concentrations in minimally pretreated saliva samples. Using 20 ?l of saliva, we demonstrate rapid (<10 min) measurement of the collagen-cleaving enzyme matrix metalloproteinase-8 (MMP-8) in saliva from healthy and periodontally diseased subjects. In addition to physiologically measurable indicators of periodontal disease, conventional measurements of salivary MMP-8 were used to validate the microfluidic assays described in this proof-of-principle study. The microchip-based POC diagnostic demonstrated is applicable to rapid, reliable measurement of proteinaceous disease biomarkers in biological fluids.
Herr, Amy E.; Hatch, Anson V.; Throckmorton, Daniel J.; Tran, Huu M.; Brennan, James S.; Giannobile, William V.; Singh, Anup K.
1. A radio-immunoassay for gastrin has been developed using partially purified porcine gastrin to raise antibodies and highly purified natural porcine gastrin I for radio-iodination with 125I. The separation of antibody-bound from free hormone was performed by a double-antibody method. 2. In this assay highly purified natural porcine gastrin I, synthetic human gastrin I, radio-iodinated porcine gastrin I, gastrin in the plasma of a healthy volunteer, a patient with pernicious anaemia and another patient with the ZollingerEllison syndrome were immunologically identical. 3. The fasting plasma gastrin concentration of fourteen gastric ulcer patients was significantly higher than that of the 113 hospital controls with no history of gastro-intestinal disease, while twenty-seven duodenal ulcer patients had gastrin levels within the normal range. 4. Plasma gastrin concentration was significantly elevated in pernicious anaemia (fifty-one patients), achlorhydria (thirty-three patients), hypochlorhydria (eleven patients) and in nine patients with histologically proven Zollinger-Ellison syndrome. 5. In human volunteers a protein meal stimulated endogenous gastrin release while a carbohydrate meal did not. Atropine sulphate I.M., and hydrochloric acid orally, produced a significant fall in the level of circulating gastrin.
An ultrasensitive and fully automated bioluminescent enzyme immunoassay (BLEIA) was developed for the detection of norovirus (NV) capsid antigen. In the evaluation tests with recombinant virus-like particles, the BLEIA demonstrated broad reactivity against several NV genotypes (genotypes 1, 3, 4, 7, 8, and 12 in genogroup I [GI] and genotypes 1, 2, 3, 4, 5, 6, 12, and 13 in GII), a wide dose-response range from 0.25 pg/ml to 10,000 pg/ml, and good reproducibility with low coefficients of variation (CVs) (within-run CVs of <2.8%, between-day CVs of <3.7%). In the evaluation tests with NV-positive fecal samples, a good correlation (y = 0.66x - 3.21, r = 0.84) between the BLEIA and real-time quantitative reverse transcription-PCR was obtained. Furthermore, in the dilution test with NV specimens, the analytical sensitivity of NV was estimated to be 10(5) to 10(6) copies/g of fecal sample, indicating that the analytical sensitivity of the BLEIA is comparable to that of commercially available molecular methods. All assay steps are fully automated, the turnaround time is 46 min, and the throughput of the assay is 120 tests/h. These results indicate that the BLEIA is potentially useful for the rapid diagnosis of NV in epidemic and sporadic gastroenteritis. PMID:23081816
A rapid, simple, and reliable competitive immunoassay was developed for measurement of lead ions in spiked food samples. Avian antibodies were produced against Pb(II). Since lead ions are too small to elicit an immune response, the metal was coupled to protein carrier Bovine Serum Albumin (BSA) using a bifunctional chelator 1-(4-isothiocyanobenzyl) ethylenediamine N,N,N',N'-tetraacetic acid (ITCBE). Poultry birds (layers) were immunized with this Pb(II)-ITCBE-BSA immunoconjugate and avian antibodies (IgY) were isolated from egg yolk. This avian antibody (IgY) produced recognized Pb(II)-ITCBE complexes as capture reagent. The assay depended on a competitive binding reaction between the antibody and Pb(II). Antibody reaction was optimized for different concentrations of antigen and antibody dilutions. Cross reactivity with other metals were below 1% in competitive ELISA. The detection range and the detection limit were 0.02-1000 mg · kg(-1) and 0.2 mg · kg(-1), respectively. Spike recovery studies in different food samples showed that the avian antibodies could recognize Pb(II) in food samples without much matrix effect. PMID:24063612
Mandappa, I M; Ranjini, A; Haware, D J; Manonmani, H K
This review aims at surveying the use of electronic energy transport between chemically identical fluorophores (i.e. donors) in studies of various protein systems. Applications of intra- and interprotein energy migration are presented that make use of polarised steady-state and time-resolved fluorescence spectroscopic techniques. The donor-donor energy migration (DDEM) and the partial donor-donor energy migration (PDDEM) models for calculating distances between
Low levels of donor chimerism on day 28 after hematopoietic stem cell transplantation are highly predictive of a subsequent rejection of donor cells A recent report on nonmyeloablative transplants has demonstrated that patients who engrafted after transplantation had at least 10% donor cells detectable at this time point. A patient is described who received a nonmyeloablative umbilical cord blood transplant and experienced subsequent full engraftment of donor cells despite the absence of donor chimerism at 4 weeks posttransplantation. PMID:12894855
Khee, William Hwang Ying; Chye, Patrick Tan Huat; Hoe, Tan Cheng; Fung, How Gee; Khiang, Heng Khee; Tee, Goh Yeow
Introduction: Due to the limited number of cadaver donors, adult living liver donor transplantation became an alternative for liver transplantation. During living liver donor transplantation, the safety and uncomplicated recovery of the donor are as important as the appropriate volume and weight of the donated graft. The middle hepatic vein causes a significant dilemma, due to the special anatomical position. The reconstruction of the middle hepatic vein branches supplying S5, S8 is suggested when the anatomically right liver lobe is transplanted. Aim: The aim of the present study was to investigate the requirements of the reconstruction of middle hepatic vein and to give an accurate description about the discrepancy between the portal vein in- and outflow. Method: The authors analyzed the liver anatomic characteristics of 130 donors undergoing living liver donor transplantation with the use of MeVis software. The so-called porto-hepatic disparity index (shift) was introduced. Results: The right hepatic vein was dominant in 64.6% of all cases, while the left hepatic vein was never observed to be dominant. The territories of V5 and V8 were responsible for the 33.2±8.9% of the right hepatic lobe area. The correlation between portal venous territory and vein dominancy were as follows: R2 = 0.7811 in the left liver lobe; R² = 0.5463 in the area of middle hepatic vein and R² = 0.5843 in the case of the right hepatic vein. The average value of the shift was 28.2%. Conclusions: The differences among the pattern of portal in- and hepatic outflow is an important issue that should be taken into consideration when deciding the necessity for reconstruction of the middle hepatic vein. Orv. Hetil., 2013, 154, 1417-1425. PMID:23996923
Liver transplant outcomes keep improving, with refinements of surgical technique, immunosuppression and post-transplant care. However, these excellent results and the limited number of organs available have led to an increasing number of potential recipients with end-stage liver disease worldwide. Deaths on waiting lists have led liver transplant teams maximize every organ offered and used in terms of pre and post-transplant benefit. Donor-recipient (D-R) matching could be defined as the technique to check D-R pairs adequately associated by the presence of the constituents of some patterns from donor and patient variables. D-R matching has been strongly analysed and policies in donor allocation have tried to maximize organ utilization whilst still protecting individual interests. However, D-R matching has been written through trial and error and the development of each new score has been followed by strong discrepancies and controversies. Current allocation systems are based on isolated or combined donor or recipient characteristics. This review intends to analyze current knowledge about D-R matching methods, focusing on three main categories: patient-based policies, donor-based policies and combined donor-recipient systems. All of them lay on three mainstays that support three different concepts of D-R matching: prioritarianism (favouring the worst-off), utilitarianism (maximising total benefit) and social benefit (cost-effectiveness). All of them, with their pros and cons, offer an exciting controversial topic to be discussed. All of them together define D-R matching today, turning into myth what we considered a reality in the past. PMID:23104164
The policies and procedures for solid-organ donation, under the auspices of the Organ Procurement and Transplantation Network, currently cannot be applied to hand donation, because a hand allograft is considered a tissue in the United States and is under the jurisdiction of the Food and Drug Administration. Hand transplant centers have developed their own protocols. This article discusses the unique elements of such protocols, including training and education, the consent process, the necessary recipient and donor data, donor management, and operating room procedures. Candidate listing, allocation, and oversight of hand donation in the future are also discussed. PMID:22051395
Background\\/purpose Living-donor pancreas transplants (LDPs) were introduced at Chiba-East National Hospital in 2004, and 12 LDPs have been performed\\u000a at this institution to date. Based on the outcome of these 12 LDPs, the efficacy and safety of LDPs are herein discussed.\\u000a \\u000a \\u000a \\u000a \\u000a Methods Twelve diabetic patients underwent LDPs; ten had simultaneous pancreas and kidney transplants from living donors, one had\\u000a pancreas transplant after
Despite the increasing use of mycophenolate mofetil (MMF) in pediatric liver transplantation recipients, data on MMF pharmacokinetics in this population are relatively scattered. This pilot study was performed to explore whether recipient age-related factors, in conjunction with donor factors, can explain variability in mycophenolic acid (MPA) exposure. Thirty-four MPA pharmacokinetic profiles were performed in 20 stable pediatric liver transplantation recipients (median age, 12 years; range, 1-18 years; median delay after liver transplant, 88 months; range, 3-179 months). Ten children were converted to MMF; the others received MMF as a primary immunosuppressive regimen. MMF was used in combination with tacrolimus. Plasma MPA concentrations were analyzed samples collected at 0, 1, 3, and 6 hours after MMF administration using the enzyme multiplied immunotechnique immunoassay. The median MMF dose was 431 mg/m2 per day (range, 189-833 mg/m2 per day) leading to a median estimated MPA-AUC0-12h of 27 mg/h/L (range, 17-79 mg/h/L). Dose-normalized MPA-AUCs were characterized by high interpatient variability. Young children receiving a liver from a pediatric donor had lower MPA exposure compared with those receiving liver from an adult donor. No correlation was seen between MPA-C0 and MPA-AUC 0-6h in infants, whereas this correlation was significant but moderate in older children. The interpatient variability of MPA exposure observed with this pilot study is an argument for developing therapeutic drug monitoring-based dose adaptation strategies in pediatric liver transplantation recipients. A marked MPA underexposure was observed among young children receiving livers from pediatric donors, indicating that higher doses (mg/m2 of body surface area) might be required to reach the same MPA exposure as in adolescents. PMID:19881404
Understanding the relationships among altruistic health acts may serve to aid therapeutic research advances. In this paper, we report on the links between two such behaviours-donating blood and carrying an organ donor card-and willingness to donate urological tissue to a tissue bank. Reasons for the differential willingness to do so are examined in this paper. A systematic sample of 259 new and returning attendees at a tertiary urology referral clinic in Ireland completed a self-report questionnaire in an outpatient setting. In addition to demographic details, details of known diagnosis of malignancy and family history of cancer; attitudes to tissue donation for research purposes were gauged using a 5-point Likert scale. Both blood donors and organ donor card carriers were more likely to be willing to donate tissue for research purposes. Blood donors were more likely want to know their overall results in comparison to nonblood donors and want their samples to be used for nonprofit research. Our hypothesis that being a blood donor would be a better predictor to donate urological tissue than being an organ donor card carrier borne out by the trends reported above. PMID:22567418
McKenzie, Kenneth D; Fitzpatrick, Patricia E; Sheehan, John D
Understanding the relationships among altruistic health acts may serve to aid therapeutic research advances. In this paper, we report on the links between two such behavioursdonating blood and carrying an organ donor cardand willingness to donate urological tissue to a tissue bank. Reasons for the differential willingness to do so are examined in this paper. A systematic sample of 259 new and returning attendees at a tertiary urology referral clinic in Ireland completed a self-report questionnaire in an outpatient setting. In addition to demographic details, details of known diagnosis of malignancy and family history of cancer; attitudes to tissue donation for research purposes were gauged using a 5-point Likert scale. Both blood donors and organ donor card carriers were more likely to be willing to donate tissue for research purposes. Blood donors were more likely want to know their overall results in comparison to nonblood donors and want their samples to be used for nonprofit research. Our hypothesis that being a blood donor would be a better predictor to donate urological tissue than being an organ donor card carrier borne out by the trends reported above.
McKenzie, Kenneth D.; Fitzpatrick, Patricia E.; Sheehan, John D.
The minimal detectable concentration (MDC), the smallest analyte concentration an immunoassay can reliably measure, is a fundamental property of an assay. Different interpretations of 'the smallest concentration an immunoassay can reliably measure' have led to different mathematical formulations of the MDC definition. We interpret this concept to mean the smallest analyte concentration the immunoassay may report as greater than the zero dose with high probability, say 0.95. Using Bayes' theorem we have developed a new MDC definition and shown that each of the current definitions approximates some component of the new one. We extend our paradigm for computing the MDC and derive a statistical framework for analyzing uncertainty in small analyte concentrations. We compute for any immunoassay measurement the probability that it exceeds the zero dose, its 95% confidence interval, its coefficient-of-variation (CV) and the probability that it is greater than any previous measurement. We illustrate the framework in a study of theoretical data based on our previous analyses of the Abbott microparticle capture enzyme immunoassay assay (MEIA) for prostate- specific antigen (PSA). The paradigm provides a sounder conceptual and computational approach for measuring reliably low concentrations of biological substances and for defining a positive result for screening and diagnostic tests.
The brain dead patient is the ideal multiorgan donor. Conditions that can lead to the state of brain death are limited. A subarachnoid haemorrhage, intracerebral haemorrhage or traumatic brain injury precede in 83% of the cases the state of brain death. Because of better prevention and treatment options of these conditions, we anticipate a further decline of brain death. Consequently,
An indigenous aqueous stream can be treated and then recycled, with a suitable donor solvent, to a coal liquefaction zone to catalyze the reaction. In one embodiment, an aqueous fraction is separated from a coal liquefaction zone effluent, a quinone solids portion of the separated fraction is concentrated within the liquid by evaporation of water therefrom to form a slurry,
Head hair samples obtained from surgery patients who received fentanyl during anesthesia were analyzed by immunoassay for the presence of fentanyl. Thirteen hair samples were collected from patients following intravenous administration of 1-6 mg of fentanyl. Additional hair samples were collected following the administration of 0.18 and 0.38 mg of sufentanil to 2 patients. The elapsed time after drug administration for all patients ranged from 7 to 273 days. Twenty control hair samples also were collected from staff members who reported no surgery or anesthesia during the previous year. All samples were initially washed with methanol, followed by extraction with methanol and reconstitution in citrate buffer. Analysis of wash and extract fractions was performed by radioimmunoassay (Coat-A-Count Fentanyl assay). Segmental analysis was performed on the surgery patients' hair samples. Eight of the fentanyl patients' hair samples contained fentanyl concentrations (equivalents) of 0.13-0.48 ng/10 mg of hair in the 'root' end. Fentanyl concentrations in the 'tip' segment were lower than those found in the 'root' segment with the exception of 1 subject whose hair sample had been collected only 7 days after surgery. The remaining 5 patients had fentanyl concentrations similar to those determined for the control subjects hair samples (0-0.08 ng/10 mg, n = 19). No correlation between hair fentanyl concentration and administered dose was found for the 13 fentanyl subjects. Both sufentanil subjects' hair samples tested negative. One control subject who had experienced environmental exposure to fentanyl had a fentanyl concentration of 0.29 ng/10 mg in the extract and 0.63 ng/10 mg in the wash fraction.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8225140
Introduction A few reports have linked regular blood donation to the lowering of parameters of lipid profile. Estimating the lipid profile is an accepted method of assessing an individuals risk for coronary heart disease, particularly if there is evidence of lipid peroxidation. Regular blood donation may lower iron stores, and this in turn lowers lipid peroxidation. This study was carried out to determine the effect of blood donation on lipid profile. Materials and methods Eighty-two participants consented to participate and were enrolled into the study, 52 of whom were regular blood donors (study group) and 30 were non-donors (control group). Venous blood (10 mL) was drawn from each subject into new plain screw-capped disposable plastic tubes. This was allowed to clot and the serum was used to determine total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein. Results The mean total cholesterol (4.66 ± 0.86 mmol/L), triglycerides (1.22 ± 0.64 mmol/L), and low-density lipoprotein (2.32 ± 0.73 mmol/L) were significantly lower in the regular blood donors than the control group (5.61 ± 1.26 mmol/L, 1.77 ± 2.9 mmol/L, and 3.06 ± 0.89 mmol/L, respectively; P < 0.05 in all cases). Also, while 42% of the study group had a low/high-density lipoprotein ratio of at least three, about 57% of the control group had a ratio of at least three (P = 0.21). Conclusion Regular blood donation may be protective against cardiovascular disease as reflected by significantly lower mean total cholesterol and low-density lipoprotein levels in regular blood donors than in non-donors.
Lung transplantation for end-stage lung disease results in prolonged survival and improved pulmonary function. However, the shortage of donor lungs has been a major limiting factor in Korea. We sought to investigate the number and utilization of donor lungs by the five institutions performing LTx in Korea, retrospectively reviewing outcomes of organs registered in the Korean Network for Organ Sharing from January to December, 2010. Lungs were offered from 270 brain-dead patients (189 males and 81 females) of mean age of 45.2 ± 14.2 years (range, 12 to 77 years). The most common cause of brain death was hemorrhage (n = 219, 81%). Only 18 (6.7%) donor lungs were used, which was low compared with kidney (93.3%), liver (86.3%), heart (26.7%), and pancreas (11.1%) use. The mean age of donors of transplanted lungs was 35.7 years (range, 14 to 51 years) compared with 45.9 years for other organs (P = .003). The characteristics of utilized donor lungs were: mean partial pressure of oxygen (PaO(2)), 300.9 mm Hg; mean smoking history, as 2.7 pack-years; and mean body mass index, 21.2 kg/m(2). The causes of refusal were medical ineligibility (n = 129) including poor PaO(2), abnormal chest x-ray, long smoking history, older age (n = 46), no properly matched recipient (n = 46), unknown (n = 17), and family withdrawal (n = 14). Only 8 (33.3%) were transplanted from standard criteria and 10 from the lungs that did not satisfy these criteria. An efficient utilization system is needed to improve lung transplantations. PMID:22564570
Paik, H C; Haam, S J; Lee, D Y; Yi, G J; Song, S W; Kim, Y T; Kang, C H; Kim, K M; Park, S I; Jheon, S H
The phenomenon of fluorescence quenching of an antibody by a specific ligand was applied in developing a technique for detection of mycotoxins, such as aflatoxin B? (AFB?), ochratoxin A, and zearalenone. Studies showed that the intrinsic fluorescence of tryptophan (Trp) residues in antibodies, promoted by excitation at 280 nm, is quenched upon binding of specific mycotoxin ligands. Fluorescence quenching in FRET system takes place in these systems as a consequence of the overlap of the emission spectra of antibody donors with the absorption spectra of the mycotoxins. Further studies focusing on the detection of AFB? revealed that the Fab fragment, the variable region of the antibody where specific binding of AFB? occurs, can be utilized to increase the sensitivity of the detection system. The results demonstrate that fluorescence of the Fab fragment is almost completely quenched by AFB? whereas emission from intact anti-AFB? is only partially quenched by this mycotoxin. The limits of detection (LODs) were found to be 0.85 and 0.09 ng mL?¹ for assays using the intact antibody and the Fab fragment, respectively, corresponding to a 10-fold enhancement. A practical application of the Fab fragment based assay system was demonstrated by its use in the detection of AFB? in spiked barley grain samples. The observations made in this effort show that the new, label-free, non-competitive, and homogeneous FRET immunoassay strategy, which requires a simple sample preparation procedure, serves as a powerful tool for the rapid and sensitive quantitative determination of organic substances such as mycotoxin. PMID:23220067
Li, Taihua; Byun, Ju-Young; Kim, Bo Bae; Shin, Yong-Beom; Kim, Min-Gon
A highly sensitive and specific sandwich enzyme immunoassay for human liver-specific antigen (LSA) was developed and its forensic application using LSA as a marker for the determination of liver injury were examined. The LSA was purified from human liver by immunoaffinity chromatography. Polystyrene ball coated with affinity-purified rabbit anti-human LSA IgG was incubated with the human LSA and then with affinity-purified anti-human LSA Fab'-horseradish peroxidase conjugate. Peroxidase activity bound to the polystyrene ball was assayed by fluorometry using 3-(4-hydroxyphenyl) propionic acid as a hydrogen donor. The detection limit for human LSA was 0.52 pg per assay. The serum LSA levels determined by this assay in healthy male and female adults were 1.5-1.6 ng/ml and 0.7-1.0 ng/ml, respectively. The recovery of LSA added to 5 microliters and 10 microliters serum samples was estimated to be 53.1-55.5% and 70.6-74.8%, respectively, and no difference in recovery between serum from males and females was observed. LSA antigenic activity in bloodstains containing LSA was detectable after storage for 30 days at room temperature. High levels of LSA were proved to exist in forensic samples taken from stabbed livers, and it was clearly possible to differentiate between samples from stabbed livers and those originating from other stabbed organs. These findings demonstrate that determination of LSA from forensic samples is useful for detecting liver injuries. PMID:8065064
Paired serum and oral-fluid (OF) specimens (n = 4,448) were collected from blood donors and patients attending local sexually transmitted disease clinics in Trinidad and Tobago and the Bahamas and were tested for the presence of human immunodeficiency virus type 1 (HIV-1) antibodies. Sera were tested by Abbott AB HIV-1/HIV-2 (rDNA) enzyme immunoassay (EIA), and positive specimens were confirmed by Cambridge HIV-1 and HIV-2 Western blotting (WB). OF specimens were collected with the OraSure collection device and were tested by Murex GACELISA and by two EIAs from Organon Teknika (the Oral Fluid Vironostika HIV-1 Microelisa System [OTC-L] and the Vironostika HIV-1 Microelisa System [OTC-M]). EIA-reactive OF specimens were confirmed by miniaturized WB (OFWB). GACELISA detected all 474 HIV-1 seropositive specimens (sensitivity, 100%). OTC-L detected 470 positive specimens (sensitivity, 99.2%), while OTC-M detected 468 positive specimens (sensitivity, 98.8%). Specificities ranged from 99.2 to 100% for the three assays. Concordance of OFWB with serum WB was 99.4%, and banding patterns determined by the two methods were similar. The immunoglobulin G (IgG) concentration of OF specimens ranged from 0.21 to 100 microg/ml, with a mean of 17.1 microg/ml. Significant differences in OF IgG concentrations were observed between HIV antibody-positive and HIV antibody-negative persons (31.94 versus 15.28 microg/ml, respectively [P < 0.0001]). These data further confirm the suitability of OF specimens for detection of HIV-1 antibodies. Currently available HIV-1 antibody assays provide sensitivities and specificities with OF specimens comparable to those achieved with serum specimens. PMID:9521138
Granade, T C; Phillips, S K; Parekh, B; Gomez, P; Kitson-Piggott, W; Oleander, H; Mahabir, B; Charles, W; Lee-Thomas, S
Paired serum and oral-fluid (OF) specimens (n = 4,448) were collected from blood donors and patients attending local sexually transmitted disease clinics in Trinidad and Tobago and the Bahamas and were tested for the presence of human immunodeficiency virus type 1 (HIV-1) antibodies. Sera were tested by Abbott AB HIV-1/HIV-2 (rDNA) enzyme immunoassay (EIA), and positive specimens were confirmed by Cambridge HIV-1 and HIV-2 Western blotting (WB). OF specimens were collected with the OraSure collection device and were tested by Murex GACELISA and by two EIAs from Organon Teknika (the Oral Fluid Vironostika HIV-1 Microelisa System [OTC-L] and the Vironostika HIV-1 Microelisa System [OTC-M]). EIA-reactive OF specimens were confirmed by miniaturized WB (OFWB). GACELISA detected all 474 HIV-1 seropositive specimens (sensitivity, 100%). OTC-L detected 470 positive specimens (sensitivity, 99.2%), while OTC-M detected 468 positive specimens (sensitivity, 98.8%). Specificities ranged from 99.2 to 100% for the three assays. Concordance of OFWB with serum WB was 99.4%, and banding patterns determined by the two methods were similar. The immunoglobulin G (IgG) concentration of OF specimens ranged from 0.21 to 100 ?g/ml, with a mean of 17.1 ?g/ml. Significant differences in OF IgG concentrations were observed between HIV antibody-positive and HIV antibody-negative persons (31.94 versus 15.28 ?g/ml, respectively [P < 0.0001]). These data further confirm the suitability of OF specimens for detection of HIV-1 antibodies. Currently available HIV-1 antibody assays provide sensitivities and specificities with OF specimens comparable to those achieved with serum specimens.
The synthesis of new hybrid ferrocene and pi-extended tetrathiafulvalene (TTF) donor(1)-pi-donor(2) molecular assemblies 16a-c has been carried out by a Wittig-Horner reaction of the respective phosphonate esters 15a-c with 2-(2-ferrocenylvinyl)-9, 10-anthraquinone (18) prepared by olefination of ferrocenecarboxaldehyde (14) and the anthraquinone phosphonium salt 17. Electrochemical studies show that the D(1)-pi-D(2) (D = donor) molecular assemblies 16a-c essentially retain the redox characteristics of both ferrocene and the pi-extended TTF components and the effects of solvent, temperature, scan rate, and working electrode are significant. Most importantly, pronounced intramolecular electronic interactions between the two donor moieties were observed by cyclic voltammetry and Osteryoung square wave voltammetry in both the ground and charged states. Semiempirical calculations support the electrochemical observations. PMID:11149856
A competitive immunoassay using capillary electrophoresis with laser-induced fluorescence was developed for vancomycin. Capillary electrophoresis using a Tris-glycine running buffer provided adequate separation of the antibody-bound from the unbound fluorescent probe (tracer) in less than 4 min. Laser-induced fluorescence polarization (LIFP) provided high sensitivity detection and simultaneous monitoring of fluorescence intensity and polarization. A fluorescence polarization value of 0.30 confirmed the formation of the antibody-tracer complex. Calibration curves showed a working linear range of 2-3 orders of magnitude with a minimum detectable concentration of 0.98 ng mL(-1) (or 1.1 fg vancomycin). Clinical samples obtained from patients undergoing vancomycin treatment were analyzed for vancomycin and the results correlated well with a standard immunoassay based on latex particle detection that was routinely used by a hospital laboratory. Only 1/10 of the reagents were needed as compared with the standard immunoassay. PMID:12537372
We characterized the magnetic markers used in biological immunoassays based on Brownian relaxation. Because the markers are composed of aggregated nanoparticles, i.e., magnetic nanoclusters, we first clarified their magnetic properties using AC susceptibility measurements, magnetization (M--H) curves, and magnetic relaxation properties. Analyzing the experimental results, we obtained the key parameters for the immunoassay, i.e., hydrodynamic diameter dh, magnetic moment mB, and anisotropy energy EB of the markers. Because these parameters were distributed in practical samples, we took their distribution into account in the analysis. Next, we showed the relationship between these parameters obtained from different samples. It was shown that mB increased approximately in proportion to dh. On the other hand, no clear correlation between mB and EB was obtained. These results were very different from those expected from single-domain nanoparticles and must be taken into account when magnetic markers are used in immunoassays based on Brownian relaxation.
This report highlights the characteristics of an okadaic acid immunoassay with limits of detection in the subfemtomole range. Two different immunoassay formats were investigated and their characteristics compared in relation to linear ranges, limits of detection, and cross-reactivity with other seafood toxins present in water and/or mussel samples. The developed ELISA system can be manipulated to quantitatively measure total diarrhetic shellfish poisoning (DSP) content or for okadaic acid and dinophysistoxin-1 individual concentrations by variation of the format of the immunoassay. Real mussel samples were validated in percentage recovery test. Calibration curves were established, and aliquots of real samples were tested. Very good recoveries were attained, highlighting the validity of the ELISA system to accurately determine the DSP concentration in mussel samples. PMID:10517143
Three donoracceptordonor triads 13 consisting of tetrathiafulvalene units attached to perylene diimides by flexible and rigid spacers were synthesized and characterized. UV\\/vis spectroscopic and cyclic voltammetric results indicate that they all show negligible intramolecular charge transfer interaction in their ground states. As compared to the reference compound 21, triads 13 display reduced fluorescence and their fluorescence lifetimes are shortened, which
This study was aimed to establish a model for detecting the donor chimerism rate following the multi-donor hematopoietic stem cell transplantations, and simplify its calculation method. Patients with hematologic disease receiving allogeneic hematopoietic stem cell transplantation including single-donor and multi-donor were selected in this study and the donor cell chimerism rates were detected, using STR-PCR combined with capillary electrophoresis. The results indicated that the peaks of the sister alleles coming from the same individual were confirmed to have the approximate areas and can be replaced each other in the situation of mixed chimerism. In the calculation model, the value between reference chimerism and approximate chimerism have no significant difference using the hypothetical peak areas, and the result was confirmed to be accepted basing on typical measurement error between sister alleles (5% - 20%). It is concluded that the areas of share peaks can be replaced by non-share peaks and this conclusion can be used to calculate the double-donor CHM (DD-CHM)(%). Compared to the D alleles, R alleles show more strategic importance because it can lead to more accurate result and allowed simplifying the arithmetic calculations for DD-CHM(%). PMID:23628049
Monoclonal antibodies against zearalenone (ZEA) were raised in mice according to the hybridoma technology and applied in different immunochemical techniques. More specifically, three formats based on the competitive direct enzyme immunoassay principle were developed: an enzyme-linked immunosorbent assay (ELISA), a flow-through gel-based immunoassay column and a flow-through membrane-based immunoassay. In ELISA, the 50% inhibitory concentration (IC50) was 0.8 ng/mL, and the limit of detection for ZEA standard solutions was 0.1 ng/mL. The antibodies showed a high ZEA (100%) and alpha-zearalenol (alpha-ZOL) (69%) recognition, while cross-reactivities with alpha-zearalanol, zearalanone, beta-zearalenol and beta- zearalanol were 42%, 22%, <1% and <1%, respectively. For standard solutions, a cut-off level at 10 ng/mL could be established for the gel- and membrane-based enzyme immunoassays. Assay time of both non-instrumental tests was 25 min for 10 samples. By including a simple sample extraction procedure, the methods were applied to wheat with IC50s in ELISA of 80 and 120 microg/kg (dilution up to 5% and 15% (v/v) of wheat matrix, respectively). The cut-off level of the gel- and membrane-based immunoassays was established at 100 microg/kg. Potentials and limitations of the developed methods were compared. The possible application for multi-mycotoxin analysis of the ELISA method based on a single monoclonal antibody was investigated. Therefore, principal component analysis and partial least squares regression data modelling were used to separate the immunoassay responses of two cross-reactants (ZEA and alpha-ZOL). PMID:19575188
Burmistrova, Natalia A; Goryacheva, Irina Yu; Basova, Evgenia Yu; Franki, Ann-Sophie; Elewaut, Dirk; Van Beneden, Katrien; Deforce, Dieter; Van Peteghem, Carlos; De Saeger, Sarah
Hematopoietic stem cell transplantation (HSCT) is a medical procedure in the field of hematology and oncology, most often performed for patients with certain cancers of the blood or bone marrow. A lot of patients have no suitable HLA-matched donor within their family, so physicians must activate a donor search process by interacting with national and international donor registries who will search their databases for adult unrelated donors or cord blood units (CBU). Information and communication technologies play a key role in the donor search process in donor registries both nationally and internationaly. One of the major challenges for donor registry computer systems is the development of a reliable search algorithm. This work discusses the top-down design of such algorithms and current practice. Based on our experience with systems used by several stem cell donor registries, we highlight typical pitfalls in the implementation of an algorithm and underlying data structure.
... be reprinted for personal, noncommercial use only. Universal blood donor type: Is there such a thing? By Mayo Clinic ... your e-mail address Sign up Question Universal blood donor type: Is there such a thing? Is there a ...
We report on a patient suffering from multiple myeloma, for whom allogeneic bone marrow transplantation was planned. Donor workup revealed monoclonal gammopathy of unknown significance. We discuss this finding and stress the importance of performing complete donor examinations.
S. O. Peters; M. Stockschläder; W. Zeller; K. Mross; M. Dürken; W. Krüger; A. R. Zander
...AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Platelets Â§ 640.21 Suitability of donors. (a) Whole blood donors shall meet the criteria for suitability prescribed in Â§ 640.3....
ObjectiveSmall donors have long been considered a potential source of organs for simultaneous pancreas-kidney transplantation (SPK) and pancreas transplantation alone (PTA). Our aim was to analyze our experience with SPK and PTA using small donors weighing
H. G. Illanes; C. M. Quarin; R. Maurette; N. G. Sánchez; L. Reniero; D. H. Casadei
The purpose of this phenomenological study was to examine the meaning of being a live liver donor. Six people between ages 27 and 53 years participated. A qualitative, in-depth, semistructured interview format was used to explore donors' thoughts and feelings about being an organ donor. Five themes were identified: (1) no turning back--how do I live without you? (2) roller coaster marathon, (3) donor network, (4) the scar, and (5) reflections--time to think. At the center of the experience was the donor's commitment to the recipient. Once donors began the process, they were determined to see it through. The process was complex, and donors received various levels of support from family, friends, health care professionals, and others. After donation, as donors recovered and were able to resume their usual daily responsibilities, they reflected on the impact of the experience and how it changed their view of life. PMID:18831484
Text Version... donor may be reinstated at 120 days post index; No donor has been reentered to date: Unconfirmed = 3/28 eligible (to 11/30); ... More results from www.fda.gov/downloads/advisorycommittees/committeesmeetingmaterials
The behavior of oxygen-related donor traps in Czochralski silicon is briefly reviewed. The experimental data from recent electron nuclear double paramagnetic resonance studies indicate that no impurity or dopant is involved in the thermal donor defect as ...
A Positive Donor Recipient Identification System for a Transfusion Service has been developed. Donor and recipient identification are established by a human and machine readable number. The Recipient ID System utilizes the standard hospital ID bracelet an...
R. Chambers M. Rubin G. Sandler T. Macnamara C. Rath
...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma Â§ 640.73 Reporting of fatal donor reactions. If a donor has a fatal reaction which, in any way, may be...
...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma Â§ 640.66 Immunization of donors. If specific immunization of a donor is to be performed, the selection...
An 18% reduction in the carboxyhemoglobin saturation (COHb) in nonsmoking Chicago blood donors occurred between 1970 and 1974, indicating that current donors are being exposed to a lower average carbon monoxide (CO) concentration than had been experienced...
R. D. Stewart C. L. Hake A. Wu T. A. Stewart J. H. Kalbfleisch
... Donor Information System (DIS) v6.0. Applicant: BioLife Plasma Services LP. ... Product: Donor Information System (DIS) v6.0. Date: 12/19/2012. -. ... More results from www.fda.gov/biologicsbloodvaccines/bloodbloodproducts/approvedproducts
The BioStar OIA Chlamydia test (BioStar, Inc., Boulder, Colo.) is a novel immunoassay system that uses changes in reflection of light to directly detect chlamydial antigen in clinical specimens. We compared the optical immunoassay (OIA) with culture for detecting Chlamydia trachomatis in ocular specimens from infants with suspected chlamydial conjunctivitis. We initially performed a retrospective evaluation, testing 152 ocular specimens previously collected for culture with the OIA. The sensitivity and specificity were 94.2 and 97%, respectively. A subsequent prospective study evaluating 37 ocular specimens from infants with suspected C. trachomatis conjunctivitis revealed a sensitivity and specificity of 100 and 92.6%, respectively. PMID:9003631
Roblin, P M; Gelling, M; Kutlin, A; Tsumura, N; Hammerschlag, M R
A powerful route to utilizing magnetic nanoparticles as labels in magnetic immunoassays is to exploit their non-linear response when they are exposed to a multi-frequency alternating magnetic field. We have upgraded this non-linear method allowing for the detection, discrimination and quantification of particles of two kinds when mixed together, with no need for spatial resolution. Each kind of particle is characterized by a specific magnetic signature based on d2B(H)/dH2. Appropriate data processing of the signature measured on a mixture of both particles allows for obtaining the amount of each particle. This will enable utilizing magnetic labels for multiparametric magnetic immunoassays.
We evaluated a new membrane dot immunobinding assay (CMV-CUBE; Difco Laboratories) for the detection of cytomegalovirus (CMV) antibody in marrow transplant patients and donors. The CMV-CUBE assay was compared with a commercially available enzyme immunoassay (EIA; CMV STAT) and a latex agglutination (LA; CMVScan) test. Serum samples were collected from 311 transplant patients and donors prior to transplantation. A total of 164 serum specimens were positive for CMV antibody by one or more of the three assays, with 153 of 164 samples (93.3%) positive by all three tests. A total of 147 serum specimens were CMV antibody negative. CMV-CUBE detected 154 of 164 (94%) of the positive samples, EIA detected 160 of 164 (97.5%), and LA detected 157 of 164 (95.7%) CMV-positive samples. Compared with EIA, CMV-CUBE had a sensitivity of 95.6% and a specificity of 99.3%. Compared with LA, CMV-CUBE had a sensitivity of 97.5% and a specificity of 99.4%. CMV-CUBE is a simple and rapid visual assay which can be used for the qualitative detection of antibody to CMV in patient serum.
Recently Bulgarian Bone Marrow Donors Registry (BBMDR) has been established and since August 2005 it has been a member of\\u000a Bone Marrow Donors Worldwide. Currently the number of healthy donors included in the BBMDR is relatively low. All donors included\\u000a in the BBMDR are typed for HLA-A, -B, -DRB loci. Phylogenetic analysis based on HLA allele frequencies shows that Bulgarians
The aim of this study was to assess the impact of living-donor liver transplantation on the donors quality of life.Among the 48 performed at our hospital from October 2003 to June 2006, 46 (27 men, 19 women; mean age, 37.4 years) were followed for more than 4 months (mean, 16.5±8 months). In April 2006, these donors participated in a survey
S. Sevmis; T. Diken; F. Boyvat; A. Torgay; M. Haberal
Established in 1979, the Committee of Donor Agencies promotes the development of small enterprise in developing countries. This site offers numerous working and research papers about the Committee of Donor Agencies and its members. Showcased on the site are the Committee's Donor Business Development Services Case Studies. The Case studies are browseable by several categories including Region, Country, Theme, and Member Agency. Also provided are the Donor Committee Guidelines and links to member agencies's sites.
Right-lobe graft has been used most frequently for living donor liver transplantation in adult patients; however, some donors cannot donate their right lobe (according to the Healey and Scroy's terminology) because the remaining residual liver would be too small. A recent study suggested the possibility of right posterior segment graft in these donors. The purpose of this study was to
Kidney transplantation from living donors is widely performed all over the world. Living nephrectomy for transplantation has no direct advantage for the donor other than increased self-esteem, but at least remains an extremely safe procedure, with a worldwide overall mortality rate of 0.03%. This theoretical risk to the donor seems to be justified by the socioeconomic advantages and increased quality
P. Bruzzone; R. Pretagostini; L. Poli; M. Rossi; P. B. Berloco
Kidney transplantation from living donors is widely performed all over the world. Living nephrectomy for transplantation has no direct advantages for the donor other than increased self-esteem, but it at least remains an extremely safe procedure, with a worldwide overall mortality of 0.03%. This theoretical risk for the donor seems to be justified by the socioeconomic advantages and increased quality
In view of the shortage of cadaveric organ donors two retrospective studies have been performed to determine the results of transplantation of non-heart-beating (NHB) donor kidneys. Graft and patient survival and renal function in the 89 cases, analyzed in these studies, showed no adverse effects of the use of NHB donor kidneys. The initial graft function was best after in
J. A. van der Vliet; M. J. H. Slooff; B. G. Rijkmans; G. Kootstra
The shortage of donor kidneys for renal transplantation is becoming more severe as the gap between the number of patients waiting for renal transplantation and the number of cadaveric organs available continues to widen. Therefore, many centres have started using non-heart-beating (NHB) donors. There was no clear plan for maximal duration of agonal period in Maastricht category NHB donors after
S. Sohrabi; A. Navarro; J. Asher; C. Wilson; A. Sanni; H. Wyrley-Birch; V. Anand; M. Reddy; D. Rix; B. Jacques; D. Manas; D. Talbot
As the rate of living kidney donor (LKD) transplantations increases, the selection of extended criteria donors such as old donors (>60-65 years) becomes more common. The pool of these old donors is probably wider than we think, especially if we tolerate a lower glomerular filtration rate (GFR) than the gold standard of 80 mL/min/1.73 m(2). Several important studies with large cohorts of living donors including old subjects have been published these last few years and give insights on the outcome in this subpopulation. The risk of death and end-stage renal disease (ESRD) is similar to that of matched controls from the general population. Post-donation GFR, as a result of glomerulopaenia, is lower in old than in younger donors but pre-donation as well as the rate of function loss is not different between young and old donors. Nearly 80% of donors over 60 have <60 mL/min GFR post-donation, the risk of cardiovascular mortality and progression to ESRD in the long term, as in the general population, is under question. Despite reduced renal function of the old kidney, the results of transplantation from an old living donor appeared to be equivalent to deceased transplantation from a younger donor. Finally, transplantation from an old living donor appeared to be a reasonably safe procedure for both the donor and the recipient and the age per se is certainly not a contraindication to donation. PMID:23543591
Cerebrovascular accidents, and cerebral hemorrhage in particular, are main causes of death among potential organ donors, wilst traumatic events are cause of death in a less percentage of donors. Being high blood pressure (HBP) a well known risk factor for cerebrovascular accidents, aim of this study was to assess its prevalence in a potential donors pool. In a three year
Daniela Degli Esposti; Nicola Venturoli; Maria Rosa Pugliese; Paolo Mazzetti Gaito; Angelo Ghirardini; Flavia Petrini; Alessandro Nanni Costa; Lorenza Ridolfi; Gerardo Martinelli
...2010-04-01 2010-04-01 false Reporting of fatal donor reactions. 640.73 Section 640...PRODUCTS Source Plasma Â§ 640.73 Reporting of fatal donor reactions. If a donor has a fatal reaction which, in any way, may be...
...2009-04-01 2009-04-01 false Reporting of fatal donor reactions. 640.73 Section 640...PRODUCTS Source Plasma Â§ 640.73 Reporting of fatal donor reactions. If a donor has a fatal reaction which, in any way, may be...
The article presents a new system for the recruitment of gamete donors. The system is a partial application of the mirror exchange system: the male partner of a couple donates sperm, and in return, he receives the guarantee that his partner benefits from a greatly reduced waiting time for donor oocytes. More specifically, the woman will obtain donor oocytes within
Anna Pia Ferraretti; Guido Pennings; Luca Gianaroli; Maria Cristina Magli
If lungs could be retrieved from cadavers after circulatory arrest, the critical shortage of donors for lung transplantation might be alleviated. To assess gas exchange after transplantation of lungs from cadaveric donors, we performed double-lung transplantation through sequential thoracotomies in 12 dogs. Donors were sacrificed by intravenous pentobarbital injection and then ventilated with 100% oxygen. Lungs were harvested 2 hours
Charles S. Roberts; Andrea M. D'Armini; Thomas M. Egan
...STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells Â§ 660.31 Suitability of the donor. Donors of peripheral blood for Reagent Red Blood Cells shall meet the criteria for donor suitability under Â§ 640.3 of this...
Umbilical cord blood (UCB) has emerged as an appealing alternative source of hematopoietic stem cells for unrelated donor transplantation. Shorter time to transplant and an improved chance of finding a suitable graft are evident advantages over bone marrow transplantation from unrelated donors. The majority of UCB transplants from unrelated donors have been performed in children, but the number in adults
The effects of the composition of PBPC grafts from matched related donors (MRDs) and matched unrelated donors (MUDs) have not been compared. In a single-center study, the compositions of 55 MRD PBPC grafts and 33 MUD grafts were studied for their effect on the rate of engraftment in patients who had evidence of donor cell engraftment on day +28. The
J Jansen; S G Hanks; L P Akard; J A Morgan; P L Nolan; M J Dugan; M I Reeves; J M Thompson
The methods commonly used for human brucellosis serological testing are agglutination tests and the complement fixation test (CFT). Among the newer serological tests, primary binding assays were developed to improve sensitivity and specificity. The competitive enzyme immunoassay (CELISA) for the detection of serum antibody to Brucella is a multispecies assay which appears to be capable of differentiating vaccinal and cross-reacting antibodies from antibodies elicited by field infection in cattle. The competing monoclonal antibody used in this assay is specific for a common epitope of smooth lipopolysaccharide (S-LPS). In this study, we compared the CELISA to the classical tests for the diagnosis of human brucellosis. The CELISA cutoff value was determined to calculate its diagnostic specificity and sensitivity. A survey was performed with 911 sera. Of the sera, 341 were from an asymptomatic population that tested negative with conventional serological tests (screening and confirmatory). Based on these samples, the CELISA specificities were determined to be 99.7 and 100% with cutoff values of 28 and 30% inhibition (%I), respectively. In a further study with 393 additional sera from an asymptomatic population found negative by the conventional screening tests, the CELISA specificities were calculated to be 96.5 and 98.8% with cutoff values of 28 and 30%I. The CELISA sensitivities were determined to be 98.3 and 94.8% with cutoff values of 28 and 30%I, respectively, for sera from 116 individuals found positive by the classical tests. For the 51 culture-positive patients, CELISA was positive for 100%, the CFT was positive for 92%, and the standard tube agglutination test (TAT) was positive for 100%. The CELISA specificity was 100% for 31 sera from patients found negative by conventional serological tests but with brucellosis-like symptoms. The CELISA is fairly rapid to perform, somewhat faster than TAT, and cross-reacts less with other antigens (or antibodies) than the conventional tests. Further, the CELISA is simpler to perform that the CFT and may readily be standardized by the use of purified S-LPS antigen and monoclonal antibody for competition.
Lucero, Nidia E.; Foglia, Luis; Ayala, Sandra M.; Gall, David; Nielsen, Klaus
We evaluated a new fully automated microparticle immunoassay for procalcitonin (LIAISON BRAHMS PCT) in comparison with a previously established manual chemiluminescence assay from the same manufacturer (LUMItest PCT, BRAHMS AG). Procalcitonin (PCT) is an early and rather specific marker of systemic bacterial infection. In addition, the efficacy of antibiotic therapy can be monitored by sequential analysis of PCT values. This is why rapid and accurate determinations of PCT are urgently required by intensive care units. The aim of this study was to evaluate in a clinical set-up a new fully automated rapid PCT test. Analytical results are compared with results obtained by a previously introduced quantitative manual test. Intra-assay coefficients of variation (CV) were found in the range of 0.94 to 7.1% at concentrations between 0.46 and 97.2 microg/l. Over a time period of 27 days the inter-assay CV was found below 4.0% at concentrations of 1.93 and 14.29 microg/l and 9.9% at 0.40 microg/l. The functional sensitivity at a CV level of 20% was determined as 0.2 microg/l. Linearity could be demonstrated in a concentration range from 0 to 445 microg/l. When serum and plasma with EDTA, citrate or heparin anti-coagulation were analyzed in parallel, no systematic bias was found. A method comparison by regression analysis showed PCT values determined by both tests in very good agreement (r = 0.99). PCT concentrations in apparently healthy subjects (n =101) were below 0.58 microg/l in line with previously published results. Patients with sepsis (n = 43) or with infectious adult respiratory distress syndrome (ARDS) (n = 28) showed median values of 22.2 and 18.9 microg/l, respectively. In a clinical set-up the LIAISON Brahms PCT assay provided rapid and accurate PCT results supporting the early detection of severe sepsis, the differentiation between systemic bacterial infection and other inflammatory diseases, and the monitoring of antibiotic therapy in septic patients. The results of the new LIAISON BRAHMS PCT assay show an excellent concordance with the LUMItest PCT. The clinical information derived from the measurements is well comparable to the results obtained with the LUMItest PCT, too. PMID:12908732
Full-thickness mucous membrane is an acceptable autogenous graft to replace the deficient conjunctiva resulting from intrinsic disease, surgical resection for carcinoma, or reconstruction of contracted sockets. The mouth provides an excellent source of mucous membrane graft material with few donor site complications. However, we encountered four cases of donor site complications after full-thickness mucous membrane grafting. All cases involved submucosal scarring with contracture. Because the inner aspect of the mouth is a multicontoured surface, the submucosal scarring resulted in web formation and limitation of movement of the mandible or lip. In two cases, we resected submucosal fibrotic scar tissue and designed a standard or multiple Z-plasty to release mucosal tension. This allowed a return to normal oral function. PMID:7081362
Twenty brain-dead potential organ donors were studied prospectively to establish thyroid function. Two or three consecutive blood samples were obtained during brain death. Seven times a sample was available before brain death occurred. Free triiodothyronine (FT3) fell in most patients (80%). Very low (<1.6 pmol\\/l) and subnormal levels (between 2 and 3 pmol\\/l) were found in 65% and 15% of
F. Masson; M. Thicoïpe; M. J. Latapie; P. Maurette
Allogeneic stem cell transplantation has a well-defined indication in the treatment of hematological malignancies. The beneficial immune effect of allogeneic marrow transplantation has long been known, but only recently have methods been developed to separate the graft-versus-leukemia (GVL) effect from graft-versus-host disease (GVHD). Animal experiments have shown that lymphocytes from the marrow donor can be transfused without causing severe GVHD
Hans-Jochem Kolb; Christoph Schmid; Xiao Chen; Anja Woiciechowski; Marie Roskrow; Martin Weber; Wolfgang Guenther; Georg Ledderose; Michael Schleuning
Kidney transplantation is the optimal option for patients with an end-stage renal\\u000adisease. The first successful transplantation with a living genetically related donor\\u000ahas been performed since 26 October 1954, when an identical twin transplant was\\u000aperformed in Boston. In the years that followed, efforts to enable non-twin\\u000atransplants unfortunately failed because effective immunosuppression was not yet\\u000aavailable. It took
Immunity to diphtheria was determined in serum samples from 1000 UK-born blood donors at the North London Blood Transfusion Centre during a three-month period in 1993; 125 women and 125 men were stratified in 10-year age groups, from 20 to 59. A tissue (vero cell)-culture toxin- neutralisation assay was used to measure serum diphtheria antitoxin concentrations. According to internationally accepted
P. A. Maple; A. Efstratiou; R. C. George; N. J. Andrews; D. Sesardic
It has been shown that all selectins recognize the carbohydrate epitopes sialyl Lewisx and sialyl Lewisa. For the establishment of the structure-activity relationship, the efficient synthesis of these tetrasaccharides and derivatives is therefore of vital interest. The glycosyl transferase-mediated approach is summarized with emphasis on the use of modified acceptors and modified sugar-nucleotide donors. A survey of the involved enzymes:
Allogeneic stem cell transplantation has a well-defined indication in the treatment of hematological malignancies. The beneficial immune effect of allogeneic marrow transplantation has long been known, but only recently have methods been developed to separate the graft-versus-leukemia (GVL) effect from graft-versus-host disease (GVHD). Animal experiments have shown that lymphocytes from the marrow donor can be transfused without causing severe GVHD if stable chimerism and tolerance is established. First clinical studies have been preformed in patients with recurrent chronic myelogenous leukemia. In these patients complete molecular remissions were induced that persist without further maintenance treatment. These results have been confirmed in larger multicenter studies in Europe and the USA. The best results were obtained in chronic myelogenous leukemia (CML); repeated successes have been reported in relapsing acute myeloid leukemia (AML), myelodysplastic syndromes and multiple myeloma (MMY), and rare responses were reported for acute lymphoid leukemia. Contrary to animal experiments GVHD has been observed in human patients although to a lesser extent than expected in transplants not given immunosuppression. Secondly myelosuppression has been observed in patients treated with relapsing CML. In CML the incidence of GVHD could be reduced by depleting CD8+ T cells from the donor lymphocyte concentrate. Alternatively only small numbers of T lymphocytes can be transfused and in the case of failing responses, the numbers of donor lymphocytes may be increased. Results in recurrent AML have been improved by the use of low-dose cytosine arabinoside, granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor mobilized blood cells as compared to lymphocytes only. In MMY the response rate is higher than in AML, but the remissions are of limited duration in most patients. Several protocols have been designed to include preemptive donor lymphocyte transfusion in patients with a high relapse risk after transplantation. Problems remain to avoid chronic GVHD and to circumvent the immune escape mechanisms of leukemia. PMID:14583671
A new donor flow formulation for momentum flux differencing has been developed to eliminate the pressure and velocity anomalies caused by fictitious momentum sources that arise when other numerical formulations are used to characterize the large density gradients associated with sodium boiling. This new formulation has been incorporated into the CAPRICORN subchannel code for sodium boiling in fuel bundles, resulting in considerable improvement in numerical performance.
Narrative type interviews were carried out with a purposive sample of 24 relatives of organ donors. Relatives were recruited through 3 Regional transplant co-ordinating centres in England. The study examined in-depth the relatives': emotional reactions to the death and donation, perceptions of the decision-making process, assessment of the problems donation caused for them, as well as the benefits it provided.
An indigenous hydrocarbon product stream boiling within a range of from about C.sub.1 -700.degree. F., preferably C.sub.1 -400.degree. F., is treated to produce an upgraded hydrocarbon fuel component and a component which can be recycled, with a suitable donor solvent, to a coal liquefaction zone to catalyze the reaction. In accordance therewith, a liquid hydrocarbon fraction with a high end
An indigenous hydrocarbon product stream boiling within a range of from about Câ-700Â°F, preferably Câ-400Â°F, is treated to produce an upgraded hydrocarbon fuel component and a component which can be recycled, with a suitable donor solvent, to a coal liquefaction zone to catalyze the reaction. In accordance therewith, a liquid hydrocarbon fraction with a high end boiling point range up
There are three main ongoing avenues to improve the power conversion efficiency of organic photovoltaics (OPV): the development of new organic materials, improved process control and novel device architecture design. In this thesis, through molecular design with chemical modification of functional organic molecules, a family of new highly absorptive solution processable squaraine (SQ) materials have been systematically synthesized and explored to improve the sunlight harvesting and charge transport. The spin-cast SQ donors are then coated with fullerene acceptors to form a unique nanocrystalline heterojunction (NcHJ) OPV device. This combination of a novel and efficient family of SQ donors, a unique NcHJ device architecture and optimized fabrication processes leads to high efficiency solar cells. For example, solar cells with efficiencies of 5.7 % and a fill factor 0.74 are achieved. We find a correlation between solar cell fill factor with the SQ thin film density, providing support for the molecular design concept that planar end groups result in close intermolecular stacking, and hence improved charge transport and exciton diffusion. Finally, thermal annealing of the films results in the formation of nanocrystalline morphologies that lead to further improvements in device performance. The microcrystal growth of SQ donors have been characterized by XRD, AFM and TEM.
Background: The Austrian Bone Marrow Donor Registry is the central search coordinating unit in charge of national and international donor searches in Austria. Patients and Methods: Between 1988 and 2010, a worldwide search for an unrelated donor of blood stem cells (URD) was initiated for 2,166 Austrian patients with haematological disorders, 1,671 adults and 495 children, by the Austrian Bone
M. Margit; M. Martina; A. Andrea; B. Barbara; L. Ljiljana; S. Sonja; H. Heinz; I. Ingrid; G. Gottfried
Graft failure is a common and severe complication of unrelated donor bone marrow transplantation (UD-BMT). However, there are few reports of a second UD-BMT in this setting. We describe 12 patients with graft failure (five primary, seven secondary) who had a second transplant, five from their original donor and seven from a different donor. Their median age was 9 years.
VL Grandage; JM Cornish; DH Pamphilon; MN Potter; CG Steward; A Oakhill; DI Marks
The majority of countries that support the use of donor insemination (DI) in artificial reproductive technology (ART) limit the number of children born from one donor. The setting of these donor limits, though intended to control for the risk of inadvertent half-sibling unions between the offspring of anonymous donors, actually have no evidence base. Controlling for the risk of inadvertent half-sibling unions may soon become unnecessary due to the increasing world-wide use of open-identity sperm donors and the revocation of donor anonymity in many countries. With the shift from anonymous to open-identity donation, the central issue is not the risk of genetic abnormality from inadvertent half-sibling consanguinity; it is the psycho-social impact of the multiple use of open-identity sperm donors. Despite this, the jurisdictions that allow or mandate the use of open-identity donors continue to observe existing limits that do not consider nor specifically control for the psycho-social impact of the multiple use of open-identity sperm donors. It is proposed that: (i) conservative interim donor limits be placed on the multiple use of open-identity donors, while research into the psycho-social impact of disclosure is undertaken to inform the establishment of evidence-based limits; and (ii) the existing limits in jurisdictions where anonymity is still commonly practiced or protected could be raised, if an updated mathematical model was used for calculating evidence-based anonymous donor limits. PMID:20172868
Although the demand of organ re-transplantation has increased, the organ shortage from brain-dead donor raises an ethical controversy about the fairness of organ allocation for re-transplantation. Living donor lobar lung transplantation has become an alternative therapeutic option to brain-dead donor lung transplantation for not only pediatric but also adult patients. Lung re-transplantation using lobes from living donors have the potential to alleviate the ethical problems. This review focused on indications, surgical techniques, perioperative care and postoperative follow-up of living donor lobar lung re-transplantation. PMID:23917194
Donor lymphocyte infusion (DLI) is commonly used to treat leukemia relapse following stem cell transplantation. In florid relapse, however, the efficacy of DLI is limited with substantial risk of severe graft-versus-host disease (GvHD). Here, we develop a novel risk-adapted strategy characterized by pre-emptive DLI initiated at the time of mixed chimerism, a small starting dose based on donor source, dose-escalation guided by real-time chimerism monitoring and withholding of DLI immediately in patients achieving full donor chimerism. A total of 178 DLIs were given to 38 patients with mixed chimerism; thereafter, 33 patients (86.8%) had donor chimerism successfully increased, including 30 (78.9%) who had chimerism fully converted back to 100% donor. Cumulative incidence of relapse was significantly lower (P=0.00004) and overall survival higher (P=0.0003) in patients with chimerism fully corrected as compared with those of patients whose chimerism remained mixed. Only 13.2% of the patients developed acute grade III-IV GvHD with no associated mortality. In conclusion, the risk-adapted DLI strategy is useful in minimizing the risk of childhood leukemia relapse, GvHD and death.
Donor lymphocyte infusion (DLI) is commonly used to treat leukemia relapse following stem cell transplantation. In florid relapse, however, the efficacy of DLI is limited with substantial risk of severe graft-versus-host disease (GvHD). Here, we develop a novel risk-adapted strategy characterized by pre-emptive DLI initiated at the time of mixed chimerism, a small starting dose based on donor source, dose-escalation guided by real-time chimerism monitoring and withholding of DLI immediately in patients achieving full donor chimerism. A total of 178 DLIs were given to 38 patients with mixed chimerism; thereafter, 33 patients (86.8%) had donor chimerism successfully increased, including 30 (78.9%) who had chimerism fully converted back to 100% donor. Cumulative incidence of relapse was significantly lower (P=0.00004) and overall survival higher (P=0.0003) in patients with chimerism fully corrected as compared with those of patients whose chimerism remained mixed. Only 13.2% of the patients developed acute grade III-IV GvHD with no associated mortality. In conclusion, the risk-adapted DLI strategy is useful in minimizing the risk of childhood leukemia relapse, GvHD and death. PMID:23995046
This article investigates how doctors configured infertile men and sperm donors in the development of donor insemination (DI) in Taiwan. In the initial stage (1950s-1970s) doctors adjusted clinical procedures to repair the deformed gender identities of infertile men. To expand DI in the late 1970s and early 1980s, doctors stressed the positive eugenics of DI by spotlighting the high intelligence of donors, playing down biological patrilineage and re-emphasising the contribution of men of higher rank in society. In the mid-1980s, when donors came to be seen as potential carriers of fatal diseases like acquired immune deficiency syndrome, doctors managed to associate risky donors with socially stigmatised men, and therefore perpetuate the conventional hierarchy of masculinities. As the intracytoplasmic sperm injection emerged in the early 1990s doctors quickly presented infertile men as universally longing for biological fatherhood and hence devalued DI in an attempt to augment paternal masculinity. These diverse configuration activities come together to create a socio-technical network of DI that most of the time perpetuates the reigning gender order, rather than destabilising it. I argue the importance of incorporating various types of participants in analysis to understand the changing dynamics of multiple masculinities along with the development of DI. PMID:20937052
Background Living donor liver transplantation (LDLT) is a valuable and legitimate treatment for patients with end-stage liver disease. Computed tomography (CT) has proven to be an important tool in the process of donor evaluation. The purpose of this study was to evaluate the significance of CT in the donor selection process. Methods Between May 1999 and October 2010 170 candidate donors underwent biphasic CT. We retrospectively reviewed the results of the CT and liver volumetry, and assessed reasons for rejection. Results 89 candidates underwent partial liver resection (52.4%). Based on the results of liver CT and volumetry 22 candidates were excluded as donors (31% of the cases). Reasons included fatty liver (n?=?9), vascular anatomical variants (n?=?4), incidental finding of hemangioma and focal nodular hyperplasia (n?=?1) and small (n?=?5) or large for size (n?=?5) graft volume. Conclusion CT based imaging of the liver in combination with dedicated software plays a key role in the process of evaluation of candidates for LDLT. It may account for up to 1/3 of the contraindications for LDLT.
The majority of patients which are eligible for a blood stem cell transplantation from an allogeneic donor do not have a suitable related donor so that an efficient unrelated donor search is a prerequisite for this treatment. Currently, there are over 7 million volunteer donors in the files of 50 registries in the world and in most countries the majority of transplants are performed from a foreign donor. Evidently, computer and communication technology must play a crucial role in the complex donor search process on the national and international level. This article describes the structural elements of the donor search process and discusses major systematic and technical issues to be addressed in the development and evolution of the supporting telematic systems. The theoretical considerations are complemented by a concise overview over the current state of the art which is given by describing the scope, relevance, interconnection and technical background of three major national and international computer appliances: The German Marrow Donor Information System (GERMIS) and the European Marrow Donor Information System (EMDIS) are interoperable business-to-business e-commerce systems and Bone Marrow Donors World Wide (BMDW) is the basic international donor information desk on the web. PMID:12216954
Heparin interferes with measurement of aminoglycosides in serum by biological, radioenzymatic, and homogeneous enzyme immunoassay techniques, but not with radioimmunoassay. At concentrations greater than or equal to 10/sup 5/ and greater than or equal to 3 X 10/sup 6/ USP units/L, respectively, it interferes with the radioenzymatic assay by inhibiting the gentamicin 3-acetyltransferase and kanamycin 6'-acetyltransferase enzymes used in the assay. It interferes with the homogeneous enzyme immunoassays for gentamicin and tobramycin (at concentrations greater than or equal to 10/sup 5/ and greater than or equal to10/sup 4/ USP units/L, respectively), but not with the commercially available homogeneous enzyme immunoassays for other drugs. Heparin interference with the homogeneous enzyme immunoassay for aminoglycosides requires both the heparin polyanion and glucose-6-phosphate dehydrogenase bound to a cationic aminoglycoside. This interference can be reproduced with dextran sulfate (but not dextran), and does not occur with free enzyme (glucose-6-phosphate dehydrogenase) alone. Heparin interference with these two assays and at concentrations that may be present in intravenous infusions or in seriously underfilled blood-collection tubes is described. (JMT)
Krogstad, D.J. (Barnes Hospital, St. Louis, MO); Granich, G.G.; Murray, P.R.; Pfaller, M.A.; Valdes, R.
Surface plasmon resonance immunoassay using a monoclonal antibody was developed to measure nivalenol (NIV) and deoxynivalenol (DON) contamination in wheat. A DON-immobilized sensor chip having high sensitivity and stability was prepared, and an SPR detection procedure was developed. The competitiv...
Background: Human serum albumin (HSA) is the most abundant plasma protein and plays key a role in metabolism. The variation in albumin concentration provides valuable information related to metabolic diseases and diagnostic application. Methods: We constructed two assay systems to quantify the albumin concentration. The immunoassay used a fluorescence (FL) dye to detect albumin in samples and employed the conventional
Sunga Choi; Eui Yul Choi; Dong Joon Kim; Jae Hoon Kim; Tai Sun Kim; Sang Wook Oh
A rapid and accurate fluorescence polarization (FP) immunoassay has been optimized for the determination of deoxynivalenol (DON) in bran and whole-wheat flour. A preliminary treatment with activated charcoal was used to eliminate the strong matrix effect due to highly colored interfering compounds p...
We introduce an automated digital microfluidic (DMF) platform capable of performing immunoassays from sample to analysis with minimal manual intervention. This platform features (a) a 90 Pogo pin interface for digital microfluidic control, (b) an integrated (and motorized) photomultiplier tube for chemiluminescent detection, and (c) a magnetic lens assembly which focuses magnetic fields into a narrow region on the surface of the DMF device, facilitating up to eight simultaneous digital microfluidic magnetic separations. The new platform was used to implement a three-level full factorial design of experiments (DOE) optimization for thyroid-stimulating hormone immunoassays, varying (1) the analyte concentration, (2) the sample incubation time, and (3) the sample volume, resulting in an optimized protocol that reduced the detection limit and sample incubation time by up to 5-fold and 2-fold, respectively, relative to those from previous work. To our knowledge, this is the first report of a DOE optimization for immunoassays in a microfluidic system of any format. We propose that this new platform paves the way for a benchtop tool that is useful for implementing immunoassays in near-patient settings, including community hospitals, physicians' offices, and small clinical laboratories. PMID:23978190
Choi, Kihwan; Ng, Alphonsus H C; Fobel, Ryan; Chang-Yen, David A; Yarnell, Lyle E; Pearson, Elroy L; Oleksak, Carl M; Fischer, Andrew T; Luoma, Robert P; Robinson, John M; Audet, Julie; Wheeler, Aaron R
Immunoassays represent a core workhorse methodology for many applications ranging from clinical diagnostics to environmental monitoring. In traditional formats such as the enzyme linked immunosorbent assay (ELISA), analytes are measured singly or in small sets. As more biomarkers are identified for disease states, there is a need to develop methods that can measure multiple markers simultaneously. Immunoaffinity arrays are one such chemistry that can achieve multi-marker screening. Most arrays are performed in either competitive or non-competitive formats, where the former are used predominantly for small molecules and the later for macromolecules. To date, ELISA and immunoaffinity array methods have relied exclusively on one of these formats and not the other. Here an immunoaffinity array method capable of performing simultaneous competitive and non-competitive analysis generated using micromosaic immunoassay techniques is introduced for the analysis of metabolites and proteins. In this report, three markers of oxidative stress were used as a model system. The method described here demonstrates the simultaneous analysis of 3-nitrotyrosine, by indirect competitive immunoassay while the enzymes catalase and superoxide dismutase are analyzed by non-competitive sandwich immunoassay. The method requires less than 1 ?L sample and 45 min for completion. Logistic curve fits and LOD statistical analysis of the binding results are presented and show good agreement with published data for these antibody-antigen systems.
Enzyme-linked immunosorbent assays (ELISAs) based on monoclonal antibodies for the detection of triazole fungicides have been developed. With this aim, hapten-protein conjugates, containing the common triazole and chlorinated aromatic moieties, were prepared. From mice immunized with these conjugates, several monoclonal antibodies (MAbs) with the ability to sensitively bind several triazoles with different specificity were obtained. Both analyte- and class-specific ELISAs were developed. The hexaconazole-specific immunoassay can determine this fungicide with a limit of detection of 0.3 mug/L in standard buffer. The so-called triazole-specific immunoassay allowed for the detection of tetraconazole, penconazole, cyproconazole, and myclobutanil, with limits of detection in the 0.1-0.7 mug/L range. These immunoassays were applied to the determination of triazoles in spiked fruit juices. Samples were adequately diluted to minimize the matrix effects. Coefficients of variation were below 30%, and recoveries ranged from 62 to 135%. Therefore, the developed immunoassays can determine triazole fungicides in fruit juices down to the maximum residue limits currently legislated, without any sample treatment other than dilution. PMID:18783243
Manclús, Juan J; Moreno, María J; Plana, Emma; Montoya, Angel
Conventional culture-based methods for detection of E. coli O157:H7 in foods and water sources are time-consuming, and results can be ambiguous, requiring further confirmation by biochemical testing and PCR. A rapid immunoassay prior to cultivation to identify presumptive positive sample would save...
The advantages of enzyme-immunoassay (EIA) over radioactive assay techniques are mainly convenience in use, in that the labelled immunoreagents are stable for long periods, and the precautions and disposal procedures required for radioisotopes are unnecessary. In addition, the us...
The light-scattering properties of submicroscopic metal particles ranging from 40 to 120 nm in diameter have recently been investigated. These particles scatter incident white light to generate monochromatic light, which can be seen either by the naked eye or by dark-field microscopy. The nanoparticles are well suited for detection in microchannel-based immunoassays. The goal of the present study was to detect Helicobacter pylori- and Escherichia coli O157:H7-specific antigens with biotinylated polyclonal antibodies. Gold particles (diameter, 80 nm) functionalized with a secondary antibiotin antibody were then used as the readout. A dark-field stereomicroscope was used for particle visualization in poly(dimethylsiloxane) microchannels. A colorimetric quantification scheme was developed for the detection of the visual color changes resulting from immune reactions in the microchannels. The microchannel immunoassays reliably detected H. pylori and E. coli O157:H7 antigens in quantities on the order of 10 ng, which provides a sensitivity of detection comparable to those of conventional dot blot assays. In addition, the nanoparticles within the microchannels can be stored for at least 8 months without a loss of signal intensity. This strategy provides a means for the detection of nanoparticles in microchannels without the use of sophisticated equipment. In addition, the approach has the potential for use for further miniaturization of immunoassays and can be used for long-term archiving of immunoassays.
Lin, Frank Y. H.; Sabri, Mahdi; Alirezaie, Javad; Li, Dongqing; Sherman, Philip M.
A sensitive enzyme immunoassay for the quantitation of mouse immunoglobulin G (mIgG) was developed using a light-addressable potentiometric (LAP) sensor as the detection system. The assay was carried out on nitrocellulose membrane filters and used sandwic...
The development of reliable, sensitive immunoassay techniques for detection of microcystins in water is becoming increasingly important. We have developed an enzyme-linked immunosorbent assay (ELISA) potentially able to detect microcystins at concentrations as low as 95 pg microcystin\\/ml water. The procedure uses antibodies extracted from the eggs of immunized chickens, eliminating the need to collect blood from laboratory rabbits. The
Two field methods for Hg, immunoassay and anodic stripping voltammetry (ASV), that can provide onsite results for quick decisions at hazardous waste sites were evaluated. Each method was applied to samples from two Superfund sites that contain high levels of Hg; Sulphur Bank Me...
In an immunoassay of a low molecular analytical target (AT), a rational design of a proper antibody specific to the AT was attempted by the application of computational chemistry. The assumption made was that a moiety of an AT and the corresponding hapten moiety of the proper antigen superimpose each other in terms of conformation. A miticide, pyridaben, was used
Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by reduced amounts of the mitochondrial protein frataxin. Frataxin levels in research studies are typically measured via Western blot analysis from patient fibroblasts, lymphocytes, or muscle biopsies; none of these is ideal for rapid detection in large scale clinical studies. Recently, a rapid, noninvasive lateral flow immunoassay was developed to
Eric C. Deutsch; Avni B. Santani; Susan L. Perlman; Jennifer M. Farmer; Catherine A. Stolle; Michael F. Marusich; David R. Lynch
Progress on development of immunoassays for the antibiotics gentamicin, tetracycline, and tylosin is discussed. The development of the gentamicin assay was completed and the assay was transferred to the Beltsville Laboratories of the US Department of Agriculture (USDA) Food Safety and Quality Service (FSQS). The sensitivity (1 ppB) is 50-fold greater than we have previously reported, and is satisfactory for
Spectinomycin is an antimicrobial agent used to treat infections caused by Gram negative and positive microorganisms in poultry, swine and non-lactating cattle. There is a need to develop a rapid and sensitive method to detect spectinomycin residues in animal tissues. A latex fluorescent immunoassay...
The olive fruit fly pheromone avidinbiotin ELISA immunoassay, based on the use of polyclonal G antibodies derived from rabbits (reported previously) and a newer assay, based on the use of polyclonal Y antibodies isolated from the eggs of laying hens (reported in this paper), were applied successfully for the analysis of natural pheromone in virgin adult female olive fruit flies.
A monoclonal antibody-based sandwich immunoassay (mAb sandwich ELISA) was developed for the detection of Fasciola hepatica antigen in the faeces of cattle. The assay was applied to samples from 100 cattle infected with F hepatica, 56 animals with parasitologically proven infections of other parasites and 100 uninfected animals. F hepatica antigen was detected in all the faecal samples from animals
To detect gatifloxacin (GAT) residue in swine urine, an electrochemical immunoassay was established. An indirect competitive immunoassay was developed, in which the coating antigen is immobilized in an enzyme-linked immunosorbent assay (ELISA) plate and GAT residue from the sample competes with the limited binding sites in added anti-GAT antibody. Horseradish peroxidase (HRP) conjugated to goat anti-rabbit IgG was used as the enzymatic label. A carbon fiber working electrode was constructed and current signals were detected by using hydrogen peroxide as a substrate and hydroquinone as an electrochemical mediator. The electrochemical immunoassay was evaluated by analysis of GAT in buffer or swine urine and an average value of half inhibition concentration (IC50) of 8.9 ng/ml was obtained. Excellent specificity of the antibody was achieved with little cross-reaction with lomefloxacin (3.0%), ciprofloxacin (3.0%), and ofloxacin (1.9%) among commonly used (fluoro)quinolones. In conclusion, the immunoassay system developed in this research can be used as a rapid, powerful and on-site analytical tool to detect GAT residue in foods and food products.
Monoclonal antibodies (mabs) are of great interest according to their homologous abilities, high specificity, and unlimited possibility of production. Mabs against different substances have been developed. They are used in many fields of application (e.g., medicine and pesticide analysis). Immunoassays performed with mabs have the advantages of easy handling and high sensitivity. The goal of this study was to develop
Ralph Lausterer; Nuria Sanvicens; M. Pilar Marco; Bertold Hock
Enzyme immunoassays represent in many cases the preferred procedure for the detection of antigens or corresponding antibodies. However, many of the current procedures are performed suboptimally. This article reviews the available designs, auxiliary recognition systems, production and purification of antibodies, conjugation procedures, solid-phase materials, recording and interpretation of results, and quality control and standardization of procedures to improve the reproducibility of tests.
The determinazione of HCG is performed by the enzyme immunoassay technique using acetylcholinesterase enzyme as lable and a pH electrode to follow the enzyme activity. The antibody to HCG is immobilized in a membrane form with a polyethylene net; to the sample a certain amount of enzyme-labeled HCG is added, the antibody bound membrane is dipped for two hours; after
The polymerase chain reaction (PCR) method is a sensitive, specific and rapid technique for virus detection. The principles of a PCR enhanced immunoassay (PIA) are described. The method combines solid phase serological techniques with the PCR, providing a versatile and sensitive method for antibody detection. By linking the antigenicity of virus particles with their content of nucleic acid, the method
Robert Aspholm; Shusheng Zuo; Jan Fohlman; Gun Frisk; Göran Friman; Jonas Blomberg
A fast competitive enzyme immunoassay (EIA) for mea- suring homovanillic acid in human urine samples was developed with a monoclonal antibody and acetylcho- linesterase as enzyme label. Enzyme detection was per- formed by an easy colorimetric assay. Monoclonal anti- bodies were screened on the basis of sensitivity, specificity, and correlation studies. EIA has a detection limit of 0.5 mmol\\/L, a
Frederic Taran; Yveline Frobert; Christophe Creminon; Jacques Grassi; Didier Olichon; Charles Mioskowski; Philippe Pradelles
The use of an enzyme as a label has a number of advantages over the use of other labels in both immunohistochemistry and immunoassay. Immunofluorescence techniques are not suitable for ultrastructural research on cells, and ferritin-labeled antibodies allow only electronmicroscopic studies. By contrast, enzyme-labeled antibodies permit localization of cellular antigens in relation to tissue structures under light microscope and also
The discrimination of viral and bacterial sepsis is an important issue in intensive care patients. For this purpose, the simultaneous measurements of different analytes such as C-reactive protein (CRP), procalcitonin (PCT), myeloperoxidase, interleukines and neopterin, are necessary. A novel optical platform was designed and realised for the implementation of fluorescence-based immunoassays. The core of the optical platform is a plastic
F. Baldini; L. Bolzoni; A. Giannetti; G. Porro; F. Senesi; C. Trono
The latex agglutination immunoassay technique uses polymer colloids as carriers for antibodies or antigens to enhance the immunological reaction. In this work, the interaction of a lipopolysaccharide (LPS) of Brucella Melitensis with two conventional latexes has been studied. Some experiments on the physical adsorption of the LPS onto these polystyrene beads have been performed and several complexes with different coverage
J. M. Peula-Garc??a; J. A. Molina-Bolivar; J. Velasco; A. Rojas; F. Galisteo-González
Folate-functionalized polyoxometalate nanoparticles have unique oxidase-like activity, which can facilitate the fast oxidation of organic dyes without using any oxidizing agents or peroxidases especially at neutral pH conditions. This nanoparticle could be used as an agent in colorimetric multiplexed immunoassays. PMID:21258749
Using polyclonal antibodies raised against clathrin, we have developed an enzyme- linked immunoassay that can specifically measure the quantity of clathrin in crude cell extracts. We found that the quantity (weight percent of total protein) of clathrin was similar in cell types that exhibit large differences in their levels of endocytosis and exocytosis (lymphoid cells, 0.11%; liver cells, 0.07%, fibroblasts,
We have established an immunoassay for pre ? 1- HDL (the initial acceptor of cellular cholesterol) using a monoclonal antibody, MAb55201. Because pre ? 1-HDL is un- stable during storage, fresh plasma must be used for pre ? 1- HDL measurements. In this study, we describe a method of stabilizing pre ? 1-HDL, and evaluate the analytical perfor- mance of
We developed a novel silica coating magnetic nanoparticle-based silver enhancement immunoassay (SEIA) for ricin toxin (RT) rapid electrical detection using interdigitated array microelectrodes (IDAMs) as electrodes. This novel system was developed by taking advantage of the separation and enrichment properties of magnetic nanoparticles (MNPs) and the catalytic properties of gold nanoparticles (GNPs). In this system, MNPs labeled with anti-ricin A
Jie Zhuang; Tao Cheng; Lizeng Gao; Yongting Luo; Quan Ren; Di Lu; Fangqiong Tang; Xiangling Ren; Dongling Yang; Jing Feng; Jingdong Zhu; Xiyun Yan
The aim of the study was to develop an indirect, robust and simple in application method for the detection of bovine leukemia virus antigen gp51. Surface-enhanced Raman scattering (SERS) was applied as detection method. Magnetic gold nanoparticles (MNP-Au) modified by antibodies in oriented or random manner were used for the binding of gp51. The high performance liquid chromatography analysis indicated that the best antibody immobilization and antigen capturing efficiency was achieved using fragmented antibodies obtained after reduction of intact antibodies with dithiothreitol. In order to increase efficiency and sensitivity of immunoassay Raman labels consisting of gold nanorods coated by 5-thio-nitrobenzoic acid layer with covalently bounded antibodies have been constructed. The LOD and LOQ of the proposed immunoassay for antigen gp51 detection were found to be 0.95?gmL(-1) and 3.14?gmL(-1), respectively. This immunoassay was successfully applied for the detection of gp51 in milk samples in a rapid, reliable and selective manner. We believe that the proposed SERS-based immunoassay format can be applied for the detection of other proteins. PMID:23334004
A competitive, direct, chemiluminescent immunoassay based on a magnetic beads (MBs) separation and gold nanoparticles (AuNPs) labelling technique to detect chloramphenicol (CAP) has been developed. Horseradish peroxidase (HRP)-labelled anti-CAP monoclonal antibody conjugated with AuNPs and antigen-immobilized MBs were prepared. After optimization parameters of immunocomplex MBs, the IC50 values of chemiluminescence magnetic nanoparticles immunoassay (CL-MBs-nano-immunoassay) were 0.017 µg L(-1) for extract method I and 0.17 µg L(-1) for extract method II. The immunoassay with two extract methods was applied to detect CAP in milk. Comparison of these two extract methods showed that extract method I was advantageous in better sensitivity, in which the sensitivity was 10 times compared to that of extract method II, while extract method II was superior in simple operation, suitable for high throughout screen. The recoveries were 86.7-98.0% (extract method I) and 80.0-103.0% (extract method II), and the coefficients of variation (CVs) were all <15%. The satisfactory recovery with both extract methods and high correlation with traditional ELISA kit in milk system confirmed that the immunomagnetic assay based on AuNPs exhibited promising potential in rapid field screening for trace CAP analysis. PMID:23512826
Properties of magnetic nanoparticles are studied for application to magnetic immunoassays utilizing a superconducting quantum interference device (SQUID). In this application, a magnetic marker is made of magnetic nanoparticles, and the binding reaction between an antigen and its antibody is detected by measuring the magnetic field from the marker. Magnetization of an assembly of the particles is simulated when the
A fast and sensitive chemiluminescent (CL) enzyme immunoassay for clenbuterol (CLB) analysis in bovine urine has been developed. Clenbuterol (CLB) specific polyclonal antibodies were raised in rabbit using a CLB azo derivative conjugated with ovalbumin. Horseradish peroxidase (HRP) was used as label and conjugated with the same derivative. In the developed competitive method, antibodies were immobilized on 384-wells black polystyrene
Aldo Roda; Anna Chiara Manetta; Francesco Piazza; Patrizia Simoni; Rossella Lelli
In tests on 375 genital tract specimens a commercially available enzyme immunoassay for Chlamydia trachomatis (IDEIA; Boots-Celltech) was found to have sensitivity values of 62% for men and 74% for women, and a specificity of 97% for both groups, relative to the results obtained by a fluorescence assay (Micro Trak; Syva). The positive predictive value and the negative predictive value
B J Thomas; M F Osborn; C Gilchrist; D Taylor-Robinson
A second generation competitive enzyme immunoassay (CELISA) for detection of bovine antibody to Brucella abortus was developed. This assay was different from previously developed CELISAs in that the detection reagent used was a recombinant combination of the receptor portions of protein A and protein G, labelled with horseradish peroxidase. This eliminates the need for polyclonal anti-mouse-enzyme conjugate reagents for detection
K. Nielsen; P. Smith; W. L. Yu; C. Elmgren; P. Nicoletti; B. Perez; R. Bermudez; T. Renteria
The extensive use of organophosphorus pesticides (OPs) in agriculture and domestic settings can result in widespread water contamination. The development of easy-to-use and rapid-screening immunoassay methods in a class-selective manner is a topic of considerable environmental interest. In this wo...
The project demonstrated that chemiluminescent acridinium esters are capable of generating a sensitive non-isotopic immunoassay for HBsAG. The chemiluminescence has been shown to have a detection limit of 0.5 ng/ml HBsAG, with a detection time of 10 secon...
In this work, we demonstrated a highly sensitive inductively coupled plasma mass spectrometric (ICPMS) method for the determination of human carcinoembryonic antigen (CEA), which combined the inherent high sensitivity of elemental mass spectrometric measurement with the signal amplification of catalytic silver deposition on immunogold tags. The silver amplification procedure was easy to handle and required cheap reagents, and the sensitivity was greatly enhanced to 60-fold after a 15 min silver amplification procedure. The experimental conditions, including detection of gold and silver by ICPMS, immunoassay parameters, silver amplification parameters, analytical performance, and clinical serum samples analysis, were investigated. The ICPMS Ag signal intensity depends linearly on the logarithm of the concentration of human CEA over the range of 0.07-1000 ng mL(-1) with a limit of detection (LOD, 3?) of 0.03 ng mL(-1) (i.e., 0.15 pM). The LOD of the proposed method is around 2 orders of magnitude lower than that by the widely used enzyme-linked immunosorbent assay (ELISA) and 1 order of magnitude lower than that by clinical routine chemiluminescence immunoassay (CLIA) or time-resolved fluoroimmunoassay (TRFIA) and conventional ICPMS immunoassay. The present strategy was applied to the determination of human CEA in clinical human serum samples, and the results were in good agreement with those obtained by chemiluminescence immunoassay. PMID:21348438
Mapping of epitopes is a crucial step for the study of immune pathways, the engineering of vaccines and the development of immunoassays. In this work, the Bacillus licheniformis ?-lactamase BlaP has been engineered to display heterologous polypeptides in a permissive and solvent-exposed loop. When combined with phage display, this modified enzyme can be used for epitope mapping by cloning random
Andy Chevigné; Nursel Yilmaz; Gilles Gaspard; Fabrizio Giannotta; Jean Marie François; Jean Marie Frère; Moreno Galleni; Patrice Filée
The journal article describes the use of a prototype immunoassay method for the determination of pentacholorphenol (PCP) in soil and sediment. PCP was used as a pesticide and wood preservative and is not currently available to the general public. The paper stresses the importan...
Background: Bence Jones proteins or monoclonal im- munoglobulin k and l free light chains (FLCs) are important markers for identifying and monitoring many patients with B-cell tumors. Automated immunoassays that measure FLCs in urine and serum have consider- able clinical potential. Methods: Sheep antibodies, specific for FLCs, were prepared by immunization with pure k and l molecules and then adsorbed
Arthur R. Bradwell; Hugh D. Carr-Smith; Graham P. Mead; Lian X. Tang; Paul J. Showell; Mark T. Drayson; Roger Drew
Background: The analytic performance and accuracy of drug detection below Substance Abuse and Mental Health Services Administration (SAMHSA) cutoffs is not well known. In some patient populations, clinically significant concentrations of abused drugs in urine may not be detected when current SAMHSA cutoffs are used. Our objectives were to define the precision pro- files of three immunoassay systems for drugs
Veronica I. Luzzi; Al N. Saunders; John W. Koenig; John Turk; Stanley F. Lo; Uttam C. Garg; Dennis J. Dietzen
A sensitive and more rapid biosensor method for detection of staphylococcal enterotoxins is needed by the food industry. Staphylococcus aureus enterotoxin B (SEB) is highly heat resistant and is a potential bioterrorism agent. Our research objective is to develop a competitive immunoassay using a su...
A sensitive and more rapid biosensor method for detection of staphylococcal enterotoxins is needed by the food industry. Staphylococcus aureus enterotoxin B (SEB) is highly heat resistant and is a potential bioterrorism agent. Our research objective is to develop a competitive immunoassay using a su...
Tetraconazole is currently used as a fungicide in fruit and vegetables. The aim of this work was the development of immunochemical techniques based on recombinant antibodies for the screening of tetraconazole residues in fruit juices. Recombinant antibodies were produced from a hybridoma cell line secreting a monoclonal antibody specific for tetraconazole and from lymphocytes of mice hyperimmunised with tetraconazole haptens conjugated to bovine serum albumin. From these antibodies, enzyme-linked immunosorbent assays in the conjugate-coated format were developed, which were able to detect tetraconazole standards down to 1ng/mL. From recovery studies with spiked samples, these immunoassays determined tetraconazole in orange and apple juices with acceptable reproducibility (coefficients of variation below 25%) and recoveries (ranging from 78% to 145%) for a screening technique. The analytical performance of RAb-based immunoassays was fairly similar to that of the MAb-based immunoassays. Due to their simplicity and high sample throughput, the developed recombinant-based immunoassays can be valuable analytical tools for the screening of tetraconazole residues in fruit juices at regulatory levels. PMID:24054232
Plana, Emma; Moreno, Maria-José; Montoya, Angel; Manclús, Juan J
This article outlines psychosocial and ethical issues to be considered when evaluating potential living organ donors. Six types of living donors are described: genetically related, emotionally related, "Good Samaritan" (both directed and nondirected), vendors, and organ exchangers. The primary domains to be assessed in the psychosocial evaluation are informed consent, motivation for donating and the decision-making process, adequacy of support (financial and social), behavioral and psychological health, and the donor-recipient relationship. Obstacles to the evaluation process include impression management, overt deception, minimization of behavioral risk factors, and cultural and language differences between the donor and the evaluator. Ethical concerns, such as the right to donate, donor autonomy, freedom from coercion, nonmaleficence and beneficence in donor selection, conflicts of interest, "reasonable" risks to donors, and recipient decision making are also explored. To fully evaluate living organ donation, studying psychosocial as well as medical outcomes is crucial. PMID:11357556
Olbrisch, M E; Benedict, S M; Haller, D L; Levenson, J L
To assist sibling bone marrow donors with the psychological and emotional distress that they may experience as donors, a sibling bone marrow donor program was developed at The Hospital for Sick Children. These donors feel overwhelming responsibility for their siblings' survival, which can lead to psychological distress. The donors are engaged in age-appropriate medical play and are encouraged to discuss their feelings and concerns about their role. After the marrow harvest, donors receive a certificate, and either they or their parents evaluate the program. Thus far, 97.5% have rated the program very helpful. These evaluations suggest that the program has a very positive effect on the sibling donor's psychosocial health. Further studies of the program's long-term success are warranted. PMID:9579018
The application of nuclear transfer technology is an interesting approach to investigate stem and progenitor cell transplantation therapy. If stem cells are used as a nuclear donor, donor cells can engraft into cloned animals without histocompatible problems. However, it is still uncertain whether donor cells can engraft to cloned animal and differentiate in vivo. To address this problem, we transplanted donor cells to dermal tissues of cloned pigs developed by using preadipocytes as donor cells. Preadipocytes are adipocytic progenitor which can differentiate to mature adipocytes in vitro. We showed that the donor preadipocytes were successfully transplanted into the cloned pigs without immune rejection and they differentiated into mature adipocytes in vivo 3 weeks after transplantation. In contrast, allogenic control preadipocytes, which can differentiate in vitro, did not differentiate in vivo. These results indicate that donor progenitor cells can differentiate in cloned animal.
Shimada, Arata [Laboratory of Developmental Engineering, Department of Life Science, Meiji University, Kawasaki, Kanagawa 214-8571 (Japan); Tomii, Ryo [Laboratory of Developmental Engineering, Department of Life Science, Meiji University, Kawasaki, Kanagawa 214-8571 (Japan); Kano, Koichiro [Laboratory of Cell Biology, Department of Animal Science, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-8510 (Japan); Nagashima, Hiroshi [Laboratory of Developmental Engineering, Department of Life Science, Meiji University, Kawasaki, Kanagawa 214-8571 (Japan)]. E-mail: firstname.lastname@example.org
Reports of prolonged drug excretion have provided the basis for the common assumption that cannabinoid metabolites may he detected in urine for a week or longer. The accuracy, sensitivity, and specificity of immunoassays for the detection of cannabinoids and metabolites are unique for a specific assay and may change overtime. it is important that individuals who select assays and those who interpret test results be aware of qualitative and quantitative changes that occur. In the present study, detection times of cannabinoids in urine were determined using cannabinoid immunoassays with 20-, 50-, and 100-ng/mL cutoffs and using gas chromatography-mass spectrometry (GC-MS). Six subjects each smoked a single marijuana cigarette (placebo, 1.75, or 3.55% delta9-tetrahydrocannabinol [THC]) each week while residing on the clinical ward of the Addiction Research Center. Each urine specimen was analyzed under blind conditions by immunoassay according to the manufacturer's instructions. The following cannabinoid reagents were evaluated: EMIT d.a.u. 100, EMIT d.a.u. 50, EMIT d.a.u. 20, EMIT II 100, EMIT II 50, Abuscreen OnLine, and Abuscreen RIA, DRI, and ADx. All urine specimens were also analyzed for 11-nor-9-carboxy-delta9-THC by GC-MS using a 15-ng/mL cutoff. Urinary cannabinoid detection times varied substantially across assays, subjects, doses, and cutoff concentrations. Detection times were shorter than previously assumed. Mean detection times increased from a maximum of 0.5 days after the low dose to 1.5 days after the high dose using the 100-ng/mL cutoff. Mean detection times were less than 1 day following the low dose and less than 2 days following high-dose exposure using the 50-ng/mL cutoff. Mean detection times ranged from 1 to 5 days after the low dose and from 3 to 6 days after the high dose using the 20-ng/mL cutoff immunoassay. GC-MS detection times were approximately twice as long as mean detection times using an immunoassay with a cutoff of 50 ng/mL. Differences in sensitivity and specificity between the available immunoassay products affected the efficiency of detection of marijuana use. These results indicate that recent reductions in cannabinoid cutoffs by military and federally mandated programs will increase detection times and improve sensitivity, as expected. However, monitoring acute marijuana usage with a commercial cannabinoid immunoassay that has a 50-ng/mL cutoff concentration provides only a narrow window of detection of 1-2 days. PMID:8926739
This paper describes the tragic case of a young woman who died of cancer of the colon after successfully donating eggs to her younger sister. Although there is no direct link between her operation and the subsequent development of bowel carcinoma, this case imparts a feeling of unease when seen in conjunction with other cases reported during the last few years. It is a reminder that little is known of the long-term consequences of some aspects of assisted conception. Women undergoing ovarian stimulation for themselves or a matched recipient have the right to be advised, in an agreed format, that there is some concern about unproven potential risks from the stimulatory drugs. The safety of egg donors must assume priority over all other considerations, including lack of donors or any moral position. The recent decision by the Human Fertilisation and Embryology Authority (HFEA) to withdraw any form of payment or recompense to egg donors does not seem to us to be based on a balance of scientific advances, patient needs and the ethics of gamete supply. They state that the intention to withdraw payments was implicit in the 1990 Human Fertilisation and Embryology (HFE) Act. However the Act was based on the Warnock report made 6 years earlier. Even in 1990 ovum donation was uncommon and fertility drugs had not yet caused any unease. The Act provided the HFEA with discretionary powers to issue directions so that the future policies would be consistent with any emerging new medical evidence. It is imperative that the HFEA provide convincing evidence on how the current policy of payment to donors harms society, donors or recipients, and how in the UK the new policy will improve medical practice in assisted conception. Successful pilot studies must precede the implementation of any new policy. Failure to do this could cause irreversible harm to the practice of assisted conception using donor gametes, which will ultimately be against the basic aims of the 1990 HFE Act. PMID:9512262
In an effort to quantify the impact of donor risk factors on recipient outcomes, the donor risk index (DRI) was developed. A high DRI correlates with poorer post-transplant survival. In this study, high-DRI donors are classified as those having DRIs >2.0, while low-DRI donors have DRIs <2.0. The aim of this study was to evaluate the cost-effectiveness of high-DRI donor use in US Transplant Centers. A Markov-based decision analytic model was created to simulate outcomes for an allocation scheme using only low-DRI donors versus a scheme using both low- and high-DRI donors. Baseline values and ranges were determined from published data and Medicare cost data. Sensitivity analyses were conducted to test model strength and parameter variability. An allocation scheme in which only low-DRI donors were used generated 5.2 quality-adjusted life years (QALYs) at a cost of $83 000/QALY. An allocation scheme using both low- and high-DRI donors generated 5.9 QALYs at a cost of $66 000/QALY. Sensitivity analyses supported the use of an allocation scheme using both low- and high-DRI donors. The overall contribution of high-DRI grafts to the donor pool and the resultant reduction in wait-list mortality make them cost-effective. PMID:24118157
Kensinger, Clark D; Dageforde, Leigh A; Moore, Derek E
Critical donor selection and testing increases the safety of blood transfusion by excluding donors at risk of transmitting infections. This study investigated the seroprevalence of and risk factors for sexually transmitted infections (STIs) among accepted and deferred blood donors in Jamaica. A total of 1015 blood donors consisting of 794 (78%) accepted donors and 221 (22%) deferred donors presenting at
A series of new N-arylpyrrole-based chromophores with the donor-?-donor structure have been designed and synthesized via Wittig-Horner-Emmons olefination and Suzuki coupling reactions. The electronic and optical properties of the designed chromophores could be well tuned by modifying the conjugation bridges and changing the groups linked to the pyrrole moieties through the C-N single bond. All the chromophores exhibited two-photon absorption activity in the range of 730-900 nm with a large two-photon absorption cross section (?1000-1700 GM). PMID:21434627
Donor-acceptor complexes of borazine (BZ) and its substituted derivatives with Lewis acids (A = MCl(3), MBr(3); M = B, Al, Ga) and Lewis bases (D = NH(3), Py) have been theoretically studied at the B3LYP/TZVP level of theory. The calculations showed that complexes with Lewis bases only are unstable with respect to dissociation into their components, while complexes with Lewis acids only (such as aluminum and gallium trihalides) are stable. It was shown that formation of ternary D?BZ?A complexes may be achieved by subsequent introduction of the Lewis acid (acceptor A) and the Lewis base (donor D) to borazine. The nature of substituents in the borazine ring, their number, and position were shown to have only minor influence on the stability of ternary D?BZ?A complexes due to the compensation effect. Much weaker acceptor properties of borazine are explained in terms of large endothermic pyramidalization energy of the boron center in the borazine ring. In contrast to borazine, binary complexes of the isoelectronic benzene were predicted to be weakly bound even in the case of very strong Lewis acids; ternary DA complexes of benzene were predicted to be unbound. The donor-acceptor complex formation was predicted to significantly reduce both the endothermicity (by 70-95 kJ mol(-1)) and the activation energy (by 40-70 kJ mol(-1)) for the borazine hydrogenation. Thus, activation of the borazine ring by Lewis acids may be a facile way for the hydrogenation of borazines and polyborazines. PMID:20964381
The idea of using the spin of a single donor atom in silicon to encode quantum information goes back to the Kane proposal  in 1998. We have now resolved the technical challenges involved in the readout and control of the electron and nuclear spin of a single atom. The key breakthrough was the development of a device structure where the donor is tunnel-coupled to the island of an electrostatically-induced single-electron transistor . This device allowed the single-shot readout of the electron spin with visibility > 90% and 3 ?s readout time . More recently we have integrated the single-shot readout device with a broadband microwave transmission line to coherently control the electron and nuclear spins. The resonance frequency of the electron is found by monitoring the excess spin-up counts while sweeping the microwave frequency. At any time, one of two possible frequencies is found to be in resonance with the electron spin, depending on the state of the nuclear spin. Alternately probing the two frequencies yields the (quantum nondemolition) single-shot readout of the nucleus, with fidelity > 99.99%. Then we demonstrate the coherent control (Rabi oscillations) of both the electron and the nucleus, both detected in single-shot mode. The ?-pulse fidelity is 70% for the electron and 99% for the nucleus. Hahn echo and multi-pulse dynamical decoupling sequences allow us to explore the true coherence of the qubits, yielding T2e200 ?s for the electron, and T2n60 ms for the nucleus. These results are fully consistent with the bulk values for donors in a natural Si sample. Further improvements in qubit coherence can be expected by moving to isotopically pure ^28Si substrates.[4pt]  B. E. Kane, Nature 393, 133 (1998).[0pt]  A. Morello et al., Phys. Rev. B 80, 081307(R) (2009).[0pt]  A. Morello et al., Nature 467, 687 (2010).
A three-dimensional quantitative structure-activity relationship (3D-QSAR) model of sulfonamide analogs binding a monoclonal antibody (MAbSMR) produced against sulfamerazine was carried out by Distance Comparison (DISCOtech), comparative molecular field analysis (CoMFA), and comparative molecular similarity indices analysis (CoMSIA). The affinities of the MAbSMR, expressed as Log10IC50, for 17 sulfonamide analogs were determined by competitive fluorescence polarization immunoassay (FPIA). The results demonstrated that the proposed pharmacophore model containing two hydrogen-bond acceptors, two hydrogen-bond donors and two hydrophobic centers characterized the structural features of the sulfonamides necessary for MAbSMR binding. Removal of two outliers from the initial set of 17 sulfonamide analogs improved the predictability of the models. The 3D-QSAR models of 15 sulfonamides based on CoMFA and CoMSIA resulted in q2 cv values of 0.600 and 0.523, and r2 values of 0.995 and 0.994, respectively, which indicates that both methods have significant predictive capability. Connolly surface analysis, which mainly focused on steric force fields, was performed to complement the results from CoMFA and CoMSIA. This novel study combining FPIA with pharmacophore modeling demonstrates that multidisciplinary research is useful for investigating antigen-antibody interactions and also may provide information required for the design of new haptens.
Operations of transplantation of kidneys taken from donors with expanded criteria with satisfactory results were made on 27 recipients of the older age group (from 60 through 76 years). Standard transplantation of the kidney was made to 20 recipients, and dual renal transplantation to 7 recipients. Mean level of creatinine in elderly patients on the 21st day was (340.9 +/- 49.3) microM/l, on the 90th day (124.6 +/- 6.9) microMl/l. PMID:22191255
Bagnenko, S F; Reznik, O N; Anan'ev, A N; Loginov, I V; Ul'iankina, I V; Skvortsov, A E; Eremich, S V; Il'ina, V A; Tutin, A P; Reznik, A O
Liver transplantation (LT) may be the best curative treatment that offers a chance of cure for the tumor and the underlying cirrhosis by complete extirpation of both. In Asia, where the supply of cadaveric grafts remains scarce and the incidence of HCC combined with chronic hepatitis B virus (HBV)- and hepatitis C virus (HCV)-related liver disease is high, adult living donor liver transplantation (LDLT) has been settled upon as a practical alternative to deceased-donor liver transplantation (DDLT). Even in Western countries, where adequate access to DDLT is feasible for HCC patients satisfying the Milan criteria, the necessity for LDLT is well established in particular for more advanced HCC patients who are disadvantaged by current allocation algorithms for grafts from deceased donors due to organ shortage, increasing waiting lists, and the expectation that many patients listed for LT will die while awaiting a suitable organ. In the field of LDLT in Asia, numerous technical innovations were achieved to secure donor safety, as well as to ensure patient survival. The experience with LDLT for HCC has been progressively increasing in many Asian countries to date. Although there are questions regarding the higher recurrence of HCC after LDLT than after DDLT, the application of the Milan and UCSF criteria to LDLT in high-volume multicenter cohorts from Japan and Korea has resulted in patient survival outcomes very similar to those following DDLT. Recently, inclusion of biologic tumor markers such as alpha fetoprotein (AFP), protein induced by vitamin K antagonist II (PIVKA II), and positive positron emission tomography (PET) in addition to parameters of tumor morphology might be the key to establishing the best criteria for LDLT for HCC. As pretransplant treatments, most LDLT centers in Asia cannot adopt the strategy of bridging therapy under scarcity of cadaveric organ donation but have to use those multi-modality treatments as a salvage intending for primary curative treatment or a downstaging therapy before LDLT. After LDLT, basically there is no difference in the management strategy for HCC recurrence between DDLD and LDLT. PMID:22941020
The Czech Bone Marrow Donor registry (CBMD) was founded in 1991 in the National HLA centre at Prague's Institute for Clinical and Experimental Medicine. In the same year, the CBMD submitted its data to the Bone Marrow Donors Worldwide (BMDW). Another line of CBMD's international cooperation is accomplished through computer linkup with the European Donor Secretariat (E.D.S) network. Donors are being recruited constantly through blood transfusion units and other volunteers are enrolled through the mass media. All the methodology used is developed in compliance with the standards of the European Federation for Immunogenetics (EFI). CBMD closely cooperates with clinical centres for transplantation of bone marrow, stem cells (PBSC) and cord blood from unrelated donors. More than 7,000 potential bone marrow typed in HLA-A, B locus have been registered. Besides potential bone marrow donors, frozen cells of cord blood are kept by CBMD. Search requests fr