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1

Optimization and validation of CEDIA drugs of abuse immunoassay tests in serum and urine on an Olympus AU 400.  

PubMed

A preliminary initial cloned enzyme donor immunoassay (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

Musshoff, F; Wolters, T; Lott, S; Ippisch, J; Gradl, S; Madea, B

2013-05-01

2

Endogenous digoxin-like immunoreactive factors (DLIF) as measured by the CEDIA digoxin assay and a fluorescence polarization immunoassay.  

PubMed

The sensitivity of a new homogeneous enzyme immunoassay for the determination of digoxin (CEDIA Digoxin assay) and a fluorescence polarization immunoassay (FPIA) to interference by digoxin-like immunoreactive factors (DLIF) was studied in sera from pregnant women, newborns, patients undergoing hemodialysis and patients with renal insufficiency, but without hemodialysis. None of the patients had been treated with digoxin or digitoxin. Cross-reactivity of DLIF in the CEDIA assay was generally lower than in the FPIA. Data on the distribution DLIF of values and method comparisons showed that sera of the four patient groups reacted in a completely different way in both assays, suggesting that the nature of DLIF in the four groups is not identical. Addition of digoxin to sera of patients not treated with this drug resulted in a reduction of the apparent DLIF concentration in the CEDIA assay and the FPIA. This shows that DLIF interference may be less pronounced in sera of patients undergoing digoxin therapy compared to untreated persons. Although the CEDIA assay is less sensitive to DLIF interference than the FPIA, further efforts are needed to reduce the extent of this interference. PMID:1509757

Schlebusch, H; Jarausch, J; Domke, I

1992-01-01

3

False-positive buprenorphine by CEDIA in patients prescribed amisulpride or sulpiride.  

PubMed

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 donor immunoassay (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

2013-05-01

4

Improved Buprenorphine Immunoassay Performance After Urine Treatment with ?-Glucuronidase.  

PubMed

Buprenorphine (BUP), a semi-synthetic opioid analgesic, is increasingly prescribed for the treatment of chronic pain and opioid dependence. Urine immunoassay screening methods are available for monitoring BUP compliance and misuse; however, these screens may have poor sensitivity or specificity. We evaluated whether the pretreatment of urine with ?-glucuronidase (BG) improves the sensitivity and overall accuracy of three BUP enzyme immunoassays when compared with liquid chromatography-tandem mass spectrometry (LC-MS-MS). Urine samples sent to our laboratories for BUP testing (n = 114) were analyzed before and after BG pretreatment by cloned enzyme donor immunoassay (CEDIA), enzyme immunoassay (EIA) and homogenous EIA (HEIA) immunoassays using a common 5 ng/mL cutoff. Total BUP and norbuprenorphine (NBUP) concentrations were measured by LC-MS-MS as the reference method. Urine BG pretreatment improved EIA, HEIA and CEDIA sensitivities from 70, 82 and 94%, respectively, to 97% for each of the three methods, when compared with LC-MS-MS. While the specificity of the EIA and HEIA remained 100% after BG pretreatment, the specificity of the CEDIA decreased from 74 to 67%. Urine pretreatment with BG is recommended to improve sensitivity of the EIA and HEIA BUP screening methods. PMID:24802159

Snyder, Marion L; Darragh, Alicia; Flood, James G; Jones, Jenny; Ropar, Kaitlin; Jarolim, Petr; Melanson, Stacy E F

2014-07-01

5

The determination of thyroxine and thyroxine uptake with new homogeneous enzyme immunoassays using Boehringer Mannheim/Hitachi analysis systems.  

PubMed

New homogeneous enzyme immunoassays for the determination of thyroxine and thyroxine uptake have been developed. The CEDIA assays are based on the cloned enzyme donor immunoassay technology, which involves fragments of beta-galactosidase prepared by genetic engineering. The assays have been adapted for Boehringer Mannheim/Hitachi analysers. The CEDIA T4/T Uptake assays were evaluated in eleven clinical chemistry laboratories on various Boehringer Mannheim/Hitachi analysis systems, using a 2-point calibration. The analytical range of the T4 test was 10 to 258 nmol/l thyroxine. The T uptake test had a measuring range between 20-50%. Depending on the concentration of the analyte (samples from hypo-, eu- or hyperthyroid patients), mean coefficients of variation ranged from 1.8 to 4.8% within-run and from 4.1 to 6.5% between-run for the T4 assay. Even better coefficients of variation were obtained for the T uptake assay (1.4 to 2.3% within-run, 2.8 to 3.3% between run). The relative inaccuracy of the CEDIA assays with respect to values assigned by other tests was satisfactory in various control sera. The T4 assay was compared with one radioimmunoassay, one enzyme immunoassay and one fluorescence polarisation immunoassay. Slopes ranging from 0.9 to 1.1 and intercepts ranging from -10 to +10 nmol/l thyroxine were obtained with two exceptions. The results of the T uptake test correlated reasonably with those of other thyroxine-binding methods. No interference was observed with icteric and lipaemic sera. Haemoglobin up to 4 g/l had no significant influence. Results of the CEDIA T Uptake test are mainly used for calculation of the free thyroxine index, in which the thyroxine value is corrected for variations of thyroxine-binding protein concentrations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1764546

Horn, K; Castiñeiras, M J; Ortolá, J; Kock, R; Perriard, F C; Bittner, S; Pairet, J V; Ers, P; Boulanger, J; Zeidner, S

1991-10-01

6

An ImmunoChip prototype for simultaneous detection of antiepileptic drugs using an enhanced one-step homogeneous immunoassay1 2 3 4  

PubMed Central

The development and characterization of a one-step homogeneous immunoassay-based multi-well ImmunoChip is reported for the simultaneous detection and quantitation of antiepileptic drugs (AEDs). The assay platform utilizes a Cloned Enzyme Donor Immunoassay (CEDIA), and a Beta-Glo assay system for generation of bioluminescent signal. Results of the one-step CEDIA for three AEDs (CBZ, carbamazepine; PHT, phenytoin; VPA, valproic acid), in the presence of serum, correlate well with the values determined by Fluorescence Polarization Immunoassay. CEDIA intra-assay and inter-assay coefficients of variation are lower than 10%. A microfabrication process, xurography, was utilized to produce the multi-well ImmunoChip. Assay reagents were dispensed, and lyophilized, in a three-layer pattern. The multi-well ImmunoChip prototype was used to detect and quantify AEDs in serum samples containing all three drugs. Luminescent signals generated from each well were recorded with a Charged Coupled Device (CCD) camera. The assays performed on an ImmunoChip were fast (5 min), requiring only small volumes of both the reagents (< 1 ?l per well) and the serum sample. The ImmunoChip assay platform described herein may be well suited for therapeutic monitoring of drugs and metabolites at the point-of-care.

Yang, Xiaoyun; Janatova, Jarmila; Juenke, JoEtta M.; McMillin, Gwendolyn A.; Andrade, Joseph D.

2007-01-01

7

Detectability of new psychoactive substances, 'legal highs', in CEDIA, EMIT, and KIMS immunochemical screening assays for drugs of abuse.  

PubMed

The increasing number of new psychoactive substances made available for recreational drug use has created a challenge for clinical toxicology and drug testing laboratories. As a consequence, the routine immunoassay drug testing may become less effective due to an increased occurrence of false negative and false positive screening results. This work aimed to extend the knowledge about analytical cross-reactivity of new substances in selected CEDIA, EMIT, and KIMS immunoassays for drugs-of-abuse screening. Urine standards were prepared by spiking blank urine with 45 new substances. Authentic urine samples from intoxication cases identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) were also studied. Several new psychoactive substances were demonstrated to display cross-reactivity in the immunoassays. CEDIA Amphetamine/Ecstasy and EMIT d.a.u. Amphetamine Class tests showed the highest reactivity towards the new drugs, which was expected since many have amphetamine-like structure and activity. In the samples from authentic cases, five new substances displayed 100% detection rate in the CEDIA Amphetamine/Ecstasy test. In conclusion, cross-reactivity data in routine urine drug screening immunoassays for a number of new psychoactive substances not studied before were reported. In both spiked and authentic urine samples, some new substances showed significant cross-reactivity and are thus detectable in the routine screening methods. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24665024

Beck, Olof; Rausberg, Linnea; Al-Saffar, Yasir; Villen, Tomas; Karlsson, Lennart; Hansson, Therese; Helander, Anders

2014-05-01

8

Immunoassays  

NASA Astrophysics Data System (ADS)

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.

Hsieh, Y.-H. Peggy

9

Performance of parallel screening of Brazilian blood donors with two HIV immunoassays: Implications for sequential immunoassay testing algorithms in other countries  

PubMed Central

Background In Brazil it is mandatory to screen donors for HIV antibodies using two immunoassays (IAs) in parallel. Confirmatory testing is performed only on reactive donors who return for counseling. The goal of this analysis was to determine if concordant IA reactivity accurately predicts infection and can be used for HIV incidence/prevalence analyses. Methods We reviewed HIV screening and confirmatory results obtained for 307,407 donations in the first year of the REDS-II study in Brazil (2007), and for 2,304,755 donations collected from 1996 to 2006 in one of the REDS-II sites (Sao Paulo). Results In the Sao Paulo site, 11,410 (0.50%) HIV-IA-reactive donations were discarded, but only 2,095 (0.09%) were reactive to both IAs. Western blot was positive on 1,002 (48%) dual-IA-reactive donors who returned for counseling. Only 4 HIV-infected donors were detected who had been missed at screening by one of the IAs; all occurred prior to 2002. The positive predictive value (PPVs) of dual-IA-reactivity varied from 45.8 to 100%, with 80–90% PPVs when using IAs from different manufacturers. If both assays yielded signal-to-cutoff (S/C) values ?3.0, PPVs ranged from 91–99%, with ~99% sensitivity for true HIV seropositivity. Conclusion Parallel testing of all donations has limited efficacy when highly sensitive IAs are used. Reactivity by two sequential IAs is useful for prevalence studies if the assays are from different manufacturers and especially if high S/C values are considered.

Sabino, Ester C.; Salles, Nanci A; de Almeida-Neto, Cesar; Barreto, Angela M.; Basques, Fernando; Barros, Emanuelle A.; Mendrone, Alfredo; Busch, Michael P

2010-01-01

10

Response of CEDIA amphetamines assay after a single dose of bitter orange.  

PubMed

Bitter orange has recently been substituted as an ingredient in many "ephedra-free" dietary supplements used for weight loss. The primary active ingredient in bitter orange is synephrine. Previous reports have documented false-positive results from ephedrine with urine amphetamine assays. Because of the similarity in chemical structure of ephedrine and synephrine, it is hypothesized that ingestion of a bitter orange supplement may have the potential to cause false-positive results with urine amphetamine assays. The purpose of this study was to determine the response of the CEDIA Amphetamines Assay after ingestion of bitter orange. Six healthy adult male volunteers were administered a single oral dose of Nature's Way Bitter Orange, a 900-mg dietary supplement extract standardized to 6% synephrine. Urine specimens were collected at baseline and 3 and 6 hours post-administration. Additional urine specimens were collected from 1 subject at 9, 12, and 15 hours after administration. All specimens were analyzed by the CEDIA Amphetamines Assay. Urine specific gravity and pH also were measured. All urine specimens demonstrated a negative response to the CEDIA Amphetamines Assay. Urine specific gravity ranged from 1.007 to 1.028, and pH ranged from 5.0 to 7.0; thus, reducing the possibility that the negative results were caused by diluted specimens or reduced excretion of synephrine into alkaline urine. This information will be of value when health care providers or those who interpret drug screens are asked to provide consultation regarding the interference of bitter orange supplements with the CEDIA Amphetamines Assay. A single-dose of Nature's Way Bitter Orange was not found to cause a false-positive response to the CEDIA Amphetamines Assay in 6 healthy adult male volunteers. PMID:16628139

Nguyen, DiemThuy T; Bui, Linda T; Ambrose, Peter J

2006-04-01

11

Immunoassay Animations  

NSDL National Science Digital Library

This site features animations showing the detailed steps involved in eight different immunoassay examples. The focus of the site is primarily on the biochemical aspects of the immunoassays, not on their analytical applications. The animations depict the following immunoassays: Dihydroxy Vitamin D, ACTH, Boneíspecific Alkaline Phosphatase, Cortisol, Deoxypyridinoline, Osteocalcin, Prolactin and Thyroxine.

Chung, Kyn W.

2011-05-24

12

Immunoassay Animations  

NSDL National Science Digital Library

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.

Chung, Kynwai.; Cowan, Bob.

1996-01-01

13

Detection of hepatitis C virus by PCR in second-generation enzyme immunoassay-seropositive blood donors by using matched pairs of fresh frozen plasma and pilot tube sera.  

PubMed Central

Between April 1993 and March 1995, 429 of 334,454 (0.13%) blood donations at the Toronto Centre of the Canadian Red Cross were reactive for hepatitis C virus (HCV) by second-generation enzyme immunoassay (EIA-2). Of the 429 EIA-2-positive donations, 189 (44%), 138 (32%), and 102 (24%) were positive, indeterminate, and negative by Second-Generation Recombinant Immunoblot Assay (RIBA-2). To assess HCV viremia and minimize the risk that specimen handling affected PCR-based detection, the qualitative AMPLICOR HCV test was performed on both pilot tube sera (PTS) and the corresponding fresh frozen plasma (FFP) from 294 EIA-2-reactive donations. AMPLICOR PCR results for PTS and FFP were 100% concordant and were confirmed by nested HCV PCR for 27 of 294 donations. The AMPLICOR HCV test was positive for 127 of 140 (91%) of RIBA-2-positive donations (81, 91, and 96% of donations with two, three, and four reactive bands, respectively), 5 of 88 (5.7%) indeterminate donations, and 0 of 66 (0%) RIBA-2-negative donations. The Third-Generation Recombinant Immunoblot Assay (RIBA-3) was performed on RIBA-2-negative, -indeterminate, and -positive, PCR-negative donations. RIBA-3 demonstrated enhanced specificity and resolved 18 of 88 (20%) of RIBA-2-indeterminate samples as HCV antibody positive. The study demonstrates that PTS are as suitable as FFP for PCR-based detection of HCV and can be used to determine if EIA-2-reactive blood donors are viremic at the time of donation.

Krajden, M; Zhao, J; Bourke, C; Scalia, V; Gill, P; Lau, W

1996-01-01

14

Colloidal nanomaterial-based immunoassay.  

PubMed

Nanomaterials have been widely developed for their use in nanomedicine, especially for immunoassay-based diagnosis. In this review we focus on the use of nanomaterials as a nanoplatform for colloidal immunoassays. While conventional heterogeneous immunoassays suffer from mass transfer limitations and consequently long assay time, colloidal immunosupports allow target capture in the entire volume, thus speeding up reaction kinetics and shortening assay time. Owing to their wide range of chemical and physical properties, nanomaterials are an interesting candidate for immunoassay development. The most popular colloidal nanomaterials for colloidal immunoassays will be discussed, as well as their influence on immune reactions. Recent advances in nanomaterial applications for different formats of immunoassays will be reported, such as nanomaterial-based indirect immunoassays, optical-based agglutination immunoassays, resonance energy transfer-based immunoassays and magnetic relaxation-based immunoassays. Finally, the future of using nanomaterials for homogeneous immunoassays dedicated to clinical diagnosis will be discussed. PMID:22734642

Teste, Bruno; Descroix, Stephanie

2012-06-01

15

Immunoassays for aflatoxins  

Microsoft Academic Search

Immunoassays for aflatoxin analysis have been regarded as valuable supplements to existing and rapidly developing chromatographic techniques. We describe six types of aflatoxin immunogens and their characteristics, reported antibodies against aflatoxins, traditional and novel labeled materials for assay signaling, three immunoassay formats, assay devices (e.g., microtiter plate and reader, lateral flow strip, electronic and optical immunosensors, and a rapid tester

Peiwu Li; Qi Zhang; Wen Zhang

2009-01-01

16

Determination of Ritalinic Acid in Autopsy Material Using SPE and  

Microsoft Academic Search

A toddler who had lived with drug addict parents, was found dead. The autopsy could not confirm any unequivocal cause of death. Therefore, a toxicological screening was ordered by the prosecutor. The goal of our examination was to identify or exclude drugs potentially contribu- ting to the death of the child. This screening involved Cloned-Enzyme-Donor-Immunoassay (CEDIA) and Fluorescence-Polarization-Immunoassay (FPIA), a

Waler Martz; Niels Tobias; Bernd Mühlbauer

17

In situ enzymatic ascorbic acid production as electron donor for CdS quantum dots equipped TiO2 nanotubes: a general and efficient approach for new photoelectrochemical immunoassay.  

PubMed

In this work, a novel photoelectrochemical (PEC) immunoanalysis format was developed for sensitive and specific detection of prostate-specific antigen (PSA) based on an in situ electron donor producing approach. Thioglycolic acid-capped CdS quantum dots (QDs) equipped TiO(2) nanotubes (NTs) were fabricated via a facile electrostatic adsorption method. The coupling of CdS QDs and TiO(2) NTs results in an enhanced excitation and photo-to-electric conversion efficiency. Using alkaline phosphatase catalytic chemistry to in situ generate ascorbic acid for electron donating, an exquisite immunosandwich protocol was successfully constructed for the PSA assay due to the dependence of the photocurrent signal on the concentration of electron donor. This work opens a different perspective for transducer design in PEC detection and provides a general format for future development of PEC immunoanalysis. PMID:23198754

Zhao, Wei-Wei; Ma, Zheng-Yuan; Yan, Dong-Yang; Xu, Jing-Juan; Chen, Hong-Yuan

2012-12-18

18

Quantum dots as FRET acceptors for highly sensitive multiplexing immunoassays  

NASA Astrophysics Data System (ADS)

Homogeneous immunoassays have the benefit that they do not require any time-consuming separation steps. FRET is one of the most sensitive homogeneous methods used for immunoassays. Due to their extremely strong absorption over a broad wavelength range the use of quantum dots as FRET acceptors allows for large Foerster radii, an important advantage for assays in the 5 to 10 nm distance range. Moreover, because of their size-tunable emission, quantum dots of different sizes can be used with a single donor for the detection of different analytes (multiplexing). As the use of organic dyes with short fluorescence decay times as donors is known to be inefficient with quantum dot acceptors, lanthanide complexes with long luminescence decays are very efficient alternatives. In this contribution we present the application of commercially available biocompatible CdSe/ZnS core/shell quantum dots as multiplexing FRET acceptors together with a single terbium complex as donor in a homogeneous immunoassay system. Foerster radii of 10 nm and FRET efficiencies of 75 % are demonstrated. The high sensitivity of the terbium-toquantum dot FRET assay is shown by sub-100-femtomolar detection limits for two different quantum dots (emitting at 605 and 655 nm) within the same biotin-streptavidin assay. Direct comparison to the FRET immunoassay "gold standard" (FRET from Eu-TBP to APC) yields a three orders of magnitude sensitivity improvement, demonstrating the big advantages of quantum dots not only for multiplexing but also for highly sensitive nanoscale analysis.

Geissler, Daniel; Hildebrandt, Niko; Charbonnière, Loïc J.; Ziessel, Raymond F.; Löhmannsröben, Hans-Gerd

2009-02-01

19

System for Gel Electrophoretic Immunoassay.  

National Technical Information Service (NTIS)

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. E. Herr A. K. Singh D. J. Throckmorton

2005-01-01

20

Mass spectrometric immunoassay  

DOEpatents

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)

2007-12-04

21

Mass spectrometric immunoassay  

DOEpatents

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

2013-07-16

22

Mass Spectrometric Immunoassay Revisited  

NASA Astrophysics Data System (ADS)

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.

Nelson, Randall W.; Borges, Chad R.

2011-06-01

23

Ultrasensitive immunoassay techniques.  

PubMed

Ultrasensitive detection of clinically important substances using assays based on ligand:binder interactions has revolutionized laboratory medicine. Various strategies have been perfected to push the analytical sensitivity of ligand:binder assays (e.g., immunoassay, blotting, nucleic acid hybridization assay) into the attomole and zeptomole region (10(-18)-10(-21) mol). These include the use of labels with amplifying properties (e.g., enzymes), multiple labeling, and cascade reactions. In addition a wide range of ultrasensitive luminescent detection reactions have been developed for conventional enzyme labels based on chemiluminescent, bioluminescent, and time-resolved fluorescent reactions. PMID:8299202

Kricka, L J

1993-10-01

24

Immunoassays of soy proteins.  

PubMed

Proteins of soybeans (Glycine max) are widely used in animal and human nutrition. In addition to the bulk of the seed storage proteins, which are classified as albumins and globulins, approximately 6% of soybean proteins are classified as inhibitors of trypsin and chymotrypsin and approximately 0.5% are sugar-binding lectins. The two major classes of inhibitors are the Kunitz trypsin inhibitor, which inhibits trypsin, and the Bowman-Birk inhibitor (BBI), which inhibits both trypsin and chymotrypsin. Unless removed or inactivated, these inhibitors and lectins can impair the nutritional quality and safety of soy-based diets. On the other hand, several studies suggest that BBI can also function as an anticarcinogen, possibly through interaction with a cellular serine protease. Good-quality soybean proteins contribute to the nutritional value of many specialty foods including infant soy formulas and milk replacers for calves, and provide texture to many processed foods. However, they may also induce occasional allergic responses in humans. This paper outlines immunoassays developed to analyze for soy proteins in different soybean lines, in processed foods, and in nonsoy foods fortified with soy proteins. An assessment of the current status of immunoassays, especially of enzyme-linked immunosorbent assays for soybean inhibitors of digestive enzymes, soy globulins, and soy lectins, demonstrates the usefulness of these methods in plant and food sciences and in medicine. PMID:12381163

Brandon, David L; Friedman, Mendel

2002-10-23

25

Immunoassays for pesticide monitoring  

NASA Astrophysics Data System (ADS)

This study compares two formats of rapid assays for the detection of pesticides (bromacil and pyrethroid based metabolites): enzyme linked immunosorbent assay (ELISA) and immunoassay with near-infrared (NIR) fluorescence detection. NIR dye immunoassay (NIRDIA) measurements were carried out by using two different instruments, both having a silicon photodiode as the detector and a laser diode for excitation. ELISA and NIRDIA were performed in a tracer format, where the specific antibody is bound to the surface of a microtiter plate well and the tracer with enzyme or fluorescent dye label competes with the analyte for the antibody binding site. It was demonstrated that the NIRDIA is at least as sensitive as the ELISA. Both assays detect pesticides in the (mu) g/L (ppb) range. Hapten- macromolecule-NIR dye-conjugates have been synthesized with various biopolymers (e.g., proteins) as carriers. The use of carrier macromolecules enables convenient purification of the cyanine dye derivatives. The mild conjugation method of the dye is based on isothiocyanate chemistry.

Wengatz, Ingrid; Szurdoki, Ferenc; Swamy, Anand R.; Evans, Lawrence, III; Patonay, Gabor; Stimmann, Eric; Delwiche, Michael; Stoutamire, Donald; Gee, Shirley J.; Hammock, Bruce D.

1995-05-01

26

Morphological resonances for multicomponent immunoassays  

NASA Astrophysics Data System (ADS)

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.

1995-06-01

27

Method and Apparatus for Gel Electrophoretic Immunoassay.  

National Technical Information Service (NTIS)

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. E. Herr A. K. Singh D. J. Throckmorton

2005-01-01

28

Donor Tag Game  

MedlinePLUS

... 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 Enter ...

29

Field Analytic Technologies: Immunoassay and Enzymatic Assays  

NSDL National Science Digital Library

This site features a discussion of immunoassays in the context of testing for environmental contaminants, including a fairly detailed explanation of how immunoassays are conducted and advantages and limitations in the analysis of environmental problems. There is also a discussion of analytical concerns - interferences, limits of detection, accuracy and precision, calibrating immunoassays, etc.

2011-06-01

30

Immunoassays for diagnosis of coagulation disorders.  

PubMed

Immunoassays play a pivotal role in the clinical laboratory. In the coagulation section of the laboratory, they are used as an aid for diagnosis of deep vein thrombosis or pulmonary embolism, thrombophilia screening, or detection of coagulation factor deficiencies, respectively. Enzyme-linked immunosorbent assay (ELISA) and latex agglutination immunoassay technologies are currently most widely used, while Luminescent Oxygen Channeling Immunoassay (LOCI®) and other chemiluminescence-based immunoassays are emerging technologies for the coagulation laboratory. However, not all immunoassay technologies employed are compatible with the workflow requirements of the coagulation laboratory, and, not all technologies are suitable for detection or quantification of every marker. This review focuses on technical and performance aspects of those immunoassay technologies that are most widely used in the coagulation laboratory, and provides a description of markers that are typically tested by immunoassays. PMID:21057714

Kappel, A; Ehm, M

2010-11-01

31

Bioelectrochemical Immunoassay of Polychlorinated Biphenyl  

SciTech Connect

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

2008-04-01

32

Sensitive chemiluminescence enzyme immunoassay for vascular endothelial growth factor/vascular permeability factor in human serum.  

PubMed

A sandwich chemiluminescence enzyme immunoassay for measuring the level of VEGF/VPF in serum was constructed. The detectability of the assay is very low (1.0 pg/ml) and the measurable range of the assay was very wide (1-1000 pg/ml). The assay showed that the average level of VEGF/VPF in human sera from healthy blood donors was approximately 19 pg/ml. PMID:8534992

Hanatani, M; Tanaka, Y; Kondo, S; Ohmori, I; Suzuki, H

1995-10-01

33

Finding a Donor  

MedlinePLUS

... and foundation partners Global transplant network Donor centers Recruitment centers International donor centers Cord blood banks Cooperative ... information Annual report Funding patient assistance Funding donor recruitment Careers Working with us Our accomplishments & recognition Career ...

34

Contacting My Donor Family  

MedlinePLUS

... 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 ...

35

Immunoassay standards for polyaromatic hydrocarbon detection  

US Patent & Trademark Office Database

An immunoassay directed at certain analytes that are polyaromatic hydrocarbons, such that the immunoreactive standard used for assay calibration allows the creation of calibration solutions of superior stability.

1998-07-14

36

Graphene-based chemiluminescence resonance energy transfer for homogeneous immunoassay.  

PubMed

We report on chemiluminescence resonance energy transfer (CRET) between graphene nanosheets and chemiluminescent donors. In contrast to fluorescence resonance energy transfer, CRET occurs via nonradiative dipole-dipole transfer of energy from a chemiluminescent donor to a suitable acceptor molecule without an external excitation source. We designed a graphene-based CRET platform for homogeneous immunoassay of C-reactive protein (CRP), a key marker for human inflammation and cardiovascular diseases, using a luminol/hydrogen peroxide chemiluminescence (CL) reaction catalyzed by horseradish peroxidase. According to our results, anti-CRP antibody conjugated to graphene nanosheets enabled the capture of CRP at the concentration above 1.6 ng mL(-1). In the CRET platform, graphene played a key role as an energy acceptor, which was more efficient than graphene oxide, while luminol served as a donor to graphene, triggering the CRET phenomenon between luminol and graphene. The graphene-based CRET platform was successfully applied to the detection of CRP in human serum samples in the range observed during acute inflammatory stress. PMID:22417160

Lee, Joon Seok; Joung, Hyou-Arm; Kim, Min-Gon; Park, Chan Beum

2012-04-24

37

Stabilization of enzyme immunoassays for atrazine  

Microsoft Academic Search

Reagent stability is an important issue in immunoassay technology. Enzyme immunoassays (EIA) for atrazine are used as an example for investigating the influence of different stabilizing agents on the activity of polyclonal and monoclonal antibodies (Ab), enzyme tracer (ET) as well as enzyme substrate after storage at different temperatures. When lyophilized Ab were stored for two weeks at 30°C, ca.

Andrea Dankwardt; Jutta Müller; Bertold Hock

1998-01-01

38

Survey of immunoassay techniques for biological analysis  

SciTech Connect

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.

Burtis, C.A.

1986-10-01

39

Enzyme immunoassay with enhanced specificity for detection of antibodies to Chlamydia trachomatis.  

PubMed Central

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

1994-01-01

40

A rapid detection of neopterin based on a label-free and homogeneous FRET immunoassay system  

NASA Astrophysics Data System (ADS)

Herein, we have developed a label-free and homogeneous fluorescence resonance energy transfer (FRET) immunoassay for the detection of neopterin (NPT), which is an early and valuable biochemical marker of cellular immunity. Owing to intrinsic fluorescence properties of antibody and NPT, anti-NPT antibody (anti-NPT) and analyte played roles as the respective donor and acceptor in the FRET immunoassay. As the concentration of NPT increases, the fluorescence intensity at ~350 nm decreases owing to the formation of increasing amounts of the anti-NPT/NPT complex in which FRET takes place. The assay system was found to display a high specificity and a low detection limit (0.14 ng mL-1) for NPT. A practical application of the FRET immunoassay system was demonstrated by its use in the detection of NPT in spiked human serum samples. The observations made in these efforts show that the homogeneous FRET immunoassay strategy, which requires a simple sample preparation procedure, serves as a powerful tool for the rapid and sensitive quantitative determination of NPT.

Li, Taihua; Kim, Bo Bae; Shim, Won-Bo; Song, Jeong-Eon; Shin, Young-Boem; Kim, Min-Gon

2013-05-01

41

Novel immunoassay formats for integrated microfluidic circuits: diffusion immunoassays (DIA)  

NASA Astrophysics Data System (ADS)

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

2000-03-01

42

Donor Cell Myeloid Sarcoma  

PubMed Central

Donor cell derived malignancies are a rare and interesting complication of allogeneic bone marrow transplantation. We present a case of a 56-year-old male with donor cell myeloid sarcoma of the stomach and myocardium.

Walshauser, Mark A.; Sojitra, Payal

2014-01-01

43

Living Donor Liver Transplantation  

MedlinePLUS

... go through certain medical tests like blood work, radiology studies, and a liver biopsy A person should ... for me to donate my liver? The recipient’s health insurance pays for the donor’s health care costs. This ...

44

Microtransferrinuria and microalbuminuria: enhanced immunoassay.  

PubMed

An enhanced-sensitivity immunoassay for urinary microtransferrin and microalbumin was devised based on protein precipitation with cold trichloroacetic acid followed by dissolution of the precipitate in a small volume of phosphate buffer. Samples can be concentrated 10-fold by this method while at the same time removing many of the chromogens present in urine. Concentrated samples were assayed by immunoturbidity and radial immunodiffusion. The average recovery for urinary microtransferrin was 82 percent and for microalbumin 91 percent. The reference range for 80 normal adults for microtransferrinuria and microalbuminuria is 0 to 0.9 and 5 to 32 mg per g creatinine, respectively. The same method can be used for the assay of other proteins such as B2-microglobulin in the urine or the cerebrospinal fluid. PMID:2513769

McCormick, C P; Shihabi, Z K; Konen, J C

1989-01-01

45

Enzyme-Enhanced Electrochemical Immunoassay for Phenytoin,  

National Technical Information Service (NTIS)

An important application of enzyme-mediated electrocatalysis is in immunoassays where the current amplification of the enzyme reaction enhances the sensitivity of the measurement. The immunological utility of the ferrocene/glucose oxidase (Fer/GOx) system...

M. Umana J. Walker M. Wani C. Whisnant E. Cook

1988-01-01

46

Colorimetric Immunoassay for Detection of Tumor Markers  

PubMed Central

Tumor markers are substances, usually proteins, produced by the body in response to cancer growth, or by the cancer tissue itself. They can be detected in blood, urine, or tissue samples, and the discovery and detection of tumor markers may provide earlier diagnosis of cancer and improved therapeutic intervention. Colorimetric immunoassays for tumor marker detection have attracted considerable attention, due to their simplicity and high efficiency. The traditionally used colorimetric immunoassays for the detection of tumor markers are based on enzyme-linked immunosorbent assays, and the great achievement of nanotechnology has further opened opportunities for the development of such kind of immunoassays. This paper will summarize recent advances in the field of colorimetric immunoassays for detecting tumor markers, which is aimed to provide an overview in this field, as well as experimental guidance for the learner.

Yin, Yongmei; Cao, Ya; Xu, Yuanyuan; Li, Genxi

2010-01-01

47

Status of Solid-Phase Enzyme Immunoassays.  

National Technical Information Service (NTIS)

Solid-phase enzyme immunoassays are becoming increasingly popular due to their sensitivity, simplicity, and versatility. The three most common types of these assays (indirect, double-antibody, and competitive binding) have been described and examples give...

G. C. Saunders

1978-01-01

48

An enzyme immunoassay for plasma betamethasone  

SciTech Connect

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.

1981-03-01

49

Immunoassays for the quantitative determination of colchicine.  

PubMed

A radioimmunoassay as well as an enzyme immunoassay for the quantitation of fmol amounts of the alkaloid colchicine have been developed. The antiserum used for both assays was raised against a conjugate of colchicoside-bovine serum albumin. The crude serum was satisfactory for the performance of the radioimmunoassay. For the enzyme immunoassay, the antibodies had to be isolated and purified by Rivanol treatment with subsequent (NH4)2SO4 precipitation. The measuring range extends from 0.1 to 100 ng colchicine for the radioimmunoassay and from 0.05 to 350 ng for the enzyme immunoassay with detection limits of 125 fmol and 25 fmol, respectively. Both immunoassays cross reacted with colchicoside and 3-demethyl-colchicine up to 80%. The colchicine content in the newly established suspension culture of Colchicum variegatum as well as the influence of various culture media on the colchicine production of this cell culture were investigated with the radioimmunoassay. The enzyme immunoassay was well suited for the quantitation of colchicine in HPLC fractions of Gloriosa and Colchicum seed extracts allowing the rapid, sensitive, and precise determination of the substance under investigation. The preliminary experiments indicate that both colchicine immunoassays can be a useful tool for the analysis of colchicine in tissue and cell culture studies, for analysis of plant extracts as well as for biosynthetic investigations. PMID:8134420

Poulev, A; Deus-Neumann, B; Bombardelli, E; Zenk, M H

1994-02-01

50

Fluorescence polarization immunoassay for zidovudine.  

PubMed

We report a fluorescence polarization immunoassay (FPIA) for zidovudine (azidothymidine; Retrovir). This assay is accurate and specific over the clinically relevant range of zidovudine concentrations in serum (from 1 to 1,250 ng/ml; from 0.004 to 4.8 microM) and is unaffected by potentially interfering compounds in the sera of patients with renal or hepatic failure. Cross-reactivity with structural analogs of zidovudine (including zidovudine glucuronide) is less than 0.05%, except for cross-reactivities of 0.2, 0.3, and 0.4% with 3-methylthymidine, 3',5'-dideoxythymidine, and A22U (the optical isomer of zidovudine), respectively. The FPIA for zidovudine is more sensitive and more specific than high-performance liquid chromatography (HPLC); it requires 50 to 60 or 200 versus 500 microliters of serum and is faster to perform (45 specimens per h with the FPIA versus 3 specimens per h with HPLC). The zidovudine FPIA compares well with the radioimmunoassay. A correlation coefficient of 0.992 was observed with 31 serum specimens examined by both methods. All three assays (FPIA, radioimmunoassay, and HPLC) are unaffected by the heat treatment used to inactivate human immunodeficiency virus. The zidovudine FPIA should be particularly useful for analyzing specimens from large numbers of human immunodeficiency virus-infected patients receiving zidovudine in current clinical trials. PMID:2679372

Granich, G G; Eveland, M R; Krogstad, D J

1989-08-01

51

Professional donors protest.  

PubMed

In New Delhi, India, professional blood donors, a group of impoverished men who sell blood for a living, reject the accusation that they have spread HIV infection through India's blood supply. Lax sterilization practices by blood banks are blamed. Secrecy surrounds those professional donors, HIV positive, due to social ostracism, and a HIV-positive report among 6 children donating blood is reported to have led to suicide attempts. Estimates of the donor population range from 20,000 to 30,000. 15-16 units at 350 ml/unit are sold a month for sometimes as little as Rs25/unit or US$.85. It is a painful profession due to the thick needles used to make blood draws and the inability to find veins particularly in winter. The Indian Medical Research Council (ICMR) in December 1991 stated that all types of blood donors were found to be HIV positive. The highest seropositivity was found among those who regularly sold blood for blood product manufacture and lowest among voluntary donors. Estimates of HIV-positive incidence in Madras was .38% for voluntary donors and 4.1% for paid donors. An explanation for the paid donor incidence according to the ICMR is that donors are reinfected with the blood portion of donated products after the separation of the plasma. If the plasma-separating machine has not been properly sterilized after each use, 1 unit of HIV-positive blood can infect several donors. For a short period beginning in 1989, blood manufacture was prohibited due to this concern, but the ban has been lifted and a technical committee has been set up to check safety. The ICMR position is compatible with the explanation offered by the leader of the Professional Blood Donors Welfare Association (PBDWA) that donors' physical and economic condition prevents the men from sexual promiscuity with prostitutes or expensive drug use. Reuse of needles and lack of proper sterilization techniques is attributed by the PBDWA as the reason for seropositivity among blood donors. No blood donors tested positive until 1987 even though testing was extensive since 1985. Official case reports of positive HIV infection as of March 1992 are 7183 people and 130 AIDS cases. Blood donors feel victimized. PMID:12318131

Girimaji, P

1992-07-01

52

Donor selection and management.  

PubMed

This article reviews recent developments in the selection, assessment, and management of the potential lung donor, which aim to increase donor organ use. The scarcity of suitable donor organs continues to limit lung transplantation, but the situation is changing. An expanded donor pool, including the now widespread use of donation after cardiac death (DCD) lungs; the use of extended donor lungs; and the ability of ex vivo lung perfusion (EVLP) to evaluate and improve donor lungs are key initiatives. These strategies have substantially lifted donor lung utilization rates from historically low levels of less than 15% to rates greater than 50%. Indeed, since 2004 there has been an accelerated year-on-year increase in the number of lungs transplanted globally. Intermediate-term studies are now confirming that long-term outcomes are not being significantly compromised and that more individuals with terminal, symptomatic lung disease are being transplanted. It is now quite clear that many of the historical factors used to define a lung as "extended" do not actually produce significantly inferior outcomes. There has been a dramatic increase in research and clinical interest in donor lung assessment, management, and novel therapeutic strategies. The lessons learned are now being applied widely beyond the lung as researchers aim to increase availability and optimize other solid organs for transplantation. PMID:23821510

Snell, Gregory I; Paraskeva, Miranda; Westall, Glen P

2013-06-01

53

Donor and Nondonor Motivations.  

National Technical Information Service (NTIS)

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

1975-01-01

54

SITE EVALUATION OF FIELD PORTABLE PENTACHLOROPHENOL IMMUNOASSAYS  

EPA Science Inventory

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...

55

Immunoassay on Free-standing Electrospun Membranes  

NASA Astrophysics Data System (ADS)

For the purpose of immunoassay, electrospun membranes can be thought as the thread-like self-assembling of nano/microbeads. Non-woven membranes of electrospun poly(caprolactone) (PCL) fibers display excellent tenacity, flexibility and suitable surface energy. These PCL membranes exhibit easy handling in air, fast spreading and wetting in aqueous solution, and rapid adsorption of protein molecules by hydrophobic interaction. After a fold-and-press process, the membrane porosity was reduced from ˜ 75% to less than 10%, while the thickness increased from ˜5 to 300 ?m. The resulting fluorescence signal from adsorbed protein increased more than 120 times. With anti-HSA and HSA-FITC as an immunoassay model, a linear detection range from 500 ng/mL down to 1 ng/mL is obtained, with a detection of limit (LOD) of ˜ 0.08 ng/mL. By comparison, conventional nitrocellulose and thicker PCL fiber electrospun membrane displayed a much higher LOD of ˜100 ng/mL. Immunoassay on free-standing electrospun membrane successfully combines the low-cost and simplicity of conventional membrane immunoassay, with the fast reaction speed and high sensitivity characteristic of magnetic nano/microbeads bioassays.

Steckl, Andrew; Wu, Dapeng; Han, Daewoo

2010-03-01

56

The right environment for the immunoassay  

SciTech Connect

For the US Environmental Protection Agency (EPA), the first in-house research effort began in 1987, when results of an early immunoassay field study verified the technology`s potential for environmental applications. Looking at the fundamental features of immunochemical reactions from the clinical laboratories, analytical chemists realized the potential value of these methods for hazardous waste site characterization and pesticide monitoring. Immunoassays rely on the interaction between an antibody and a target analyte. For environmental purposes, enzyme immunoassays are generally used. After the target analyte binds to the antibody, an enzymatic reaction yields a colorimetric change. This change, read visually or by a spectrophotometer, indicates the concentration of the target analyte. Promising results with assays for compounds (such as paraquat and pentachlorophenol) and compound groups (such as total petroleum hydrocarbons and polychlorinated biphenyls) spurred interest among various entrepreneurs. The first target market for immunoassays was environmental engineers and field crews who needed quick answers on-site to determine the direction of further remediation efforts.

Emon, J.M. Van; Gerlach, C.L.

1995-11-01

57

Development of a Rapid Immunoassay for Syphilis.  

National Technical Information Service (NTIS)

A simple, easy and quick EIA for antibody to Treponema pallidum (Tp) was developed. It is tentatively called DD-EIA (dot diffusion enzyme immunoassay). The center of glass fiber (Quartz preferred) filter paper is marked as a tiny dot with a pencil. 25 to ...

T. M. Lin J. F. Geigel

1987-01-01

58

Toxocariasis: serological diagnosis by enzyme immunoassay  

Microsoft Academic Search

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

D H de Savigny; A Voller; A W Woodruff

1979-01-01

59

Improving the specificity of digoxin immunoassays.  

PubMed

The overall reliability of measuring digoxin in serum improved significantly with the discovery and application of immunoassays. However, because of the low concentration of digoxin being measured, its narrow therapeutic range in serum, and the presence of endogenous digoxin-like immunoreactive factors (DLIF), developing assays for measuring digoxin still pose formidable challenges. In this presentation, recent developments in the characterization of DLIF from bovine adrenal cortex and human serum are described. Data accumulated to date suggest there is one principal endogenous molecular factor (DLIF) in humans that cross-reacts with anti-digoxin antibodies. This factor exists at sufficiently high concentrations in some patients to interfere with measurements of digoxin by most digoxin immunoassays. All digoxin immunoassays should be tested to interference from this endogenous factor. Various techniques for reducing DLIF cross-reactivity are reviewed. The isolation and purification of DLIF now provides new approaches for selecting specific anti-digoxin antibodies used in developing more accurate digoxin immunoassays. PMID:1509756

Valdes, R

1992-01-01

60

Isotope-labeled immunoassays without radiation waste  

PubMed Central

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.

2000-01-01

61

IMMUNOASSAY FOR P-NITROPHENOL IN URINE  

EPA Science Inventory

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...

62

Hepatitis C antibody prevalence in blood donors in different governorates in Egypt  

Microsoft Academic Search

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

Ray R. Arthur; Nassef Farahat Hassan; Mahasan Yousef Abdallah; Mohamed Said El-Sharkawy; Magdy Darwish Saad; Barbara G. Hackbart; Imam Zaghloul Imam

1997-01-01

63

FRET-Based Quantum Dot Immunoassay for Rapid and Sensitive Detection of Aspergillus amstelodami  

PubMed Central

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

2011-01-01

64

Multi-organ donor transmission of hepatitis C virus to five solid organ transplant recipients and lack of transmission to corneal transplant recipients  

Microsoft Academic Search

Background: A multi-organ donor seronegative for hepatitis C virus (HCV) by 1st generation enzyme immunoassay (EIA) supplied 5 solid organs and 2 corneas to 7 recipients. This donor was retrospectively shown to be 2nd generation HCV EIA-positive and polymerase chain reaction (PCR)-positive. All 5 solid organ recipients but none of the corneal recipients developed HCV infection.Objectives: To demonstrate the discordance

Mel Krajden; Fouad Bishai; Corinna Quan; Jim Mahony; James Brunton; David Rootman; Jiu Zhao; Wendy Lau; Gregory Snell; Janet Maurer; Steve Kesten; David Colby

1995-01-01

65

TSE Diagnostics: Recent Advances in Immunoassaying Prions  

PubMed Central

Transmissible spongiform encephalopathies (TSEs) or prion diseases are a group of rare fatal neurodegenerative diseases, affecting humans and animals. They are believed to be the consequence of the conversion of the cellular prion protein to its aggregation-prone, ?-sheet-rich isoform, named prion. Definite diagnosis of TSEs is determined post mortem. For this purpose, immunoassays for analyzing brain tissue have been developed. However, the ultimate goal of TSE diagnostics is an ante mortem test, which would be sensitive enough to detect prions in body fluids, that is, in blood, cerebrospinal fluid, or urine. Such a test would be of paramount importance also for screening of asymptomatic carriers of the disease with the aim of increasing food, drugs, and blood-derived products safety. In the present paper, we have reviewed recent advances in the development of immunoassays for the detection of prions.

Lukan, Anja; Vranac, Tanja; Curin Serbec, Vladka

2013-01-01

66

Miniaturized immunoassay microfluidic system with electrokinetic control.  

PubMed

A portable heterogeneous immunoassay system is presented in this paper. It consists of a poly(dimethylsiloxane) (PDMS) based microfluidic chip as the immunoreactor, a miniaturized programmable high voltage sequencer as the power supply and the flow controller, and a laser-optical fiber fluorescence detection module as the signal reader. The operation of this immunoassay system is automatic. The sequential reagent dispensing and washing processes are controlled by the programmable sequencer. The reagent consumption was only 12 microL and the assay time was only 26 min. The detection limit for Escherichia coli O157:H7 bacterial antigen with this miniaturized system was 0.3 ng/muL, lower than that obtained using fluorescence microscope in previous studies. PMID:16289606

Xiang, Qing; Hu, Guoqing; Gao, Yali; Li, Dongqing

2006-04-15

67

Development and Clinical Evaluation of a Recombinant Antigen-Based Cytomegalovirus Immunoglobulin M Automated Immunoassay Using the Abbott AxSYM Analyzer  

Microsoft Academic Search

A new microparticle enzyme immunoassay (MEIA), the Cytomegalovirus (CMV) Immunoglobulin M (IgM) test, was developed on the Abbott AxSYM analyzer. This test uses recombinant CMV antigens derived from portions of four structural and nonstructural proteins of CMV: pUL32 (pp150), pUL44 (pp52), pUL83 (pp65), and pUL80a (pp38). A total of 1,608 specimens from random volunteer blood donors (n 5 300), pregnant

G. T. MAINE; R. STRICKER; M. SCHULER; J. SPESARD; S. BROJANAC; B. IRIARTE; K. HERWIG; T. GRAMINS; B. COMBS; J. WISE; H. SIMMONS; T. GRAM; J. LONZE; D. RUZICKI; B. BYRNE; J. D. CLIFTON; L. E. CHOVAN; D. WACHTA; C. HOLAS; D. WANG; T. WILSON; S. TOMAZIC-ALLEN; M. A. CLEMENTS; G. L. WRIGHT; T. LAZZAROTTO; A. RIPALTI; M. P. LANDINI

2000-01-01

68

Independent donor ethical assessment: aiming to standardize donor advocacy.  

PubMed

Living organ donation has become more common across the world. To ensure an informed consent process, given the complex issues involved with organ donation, independent donor advocacy is required. The choice of how donor advocacy is administered is left up to each transplant center. This article presents the experience and process of donor advocacy at University of Texas Southwestern Medical Center administered by a multidisciplinary team consisting of physicians, surgeons, psychologists, medical ethicists and anthropologists, lawyers, a chaplain, a living kidney donor, and a kidney transplant recipient. To ensure that advocacy remains fair and consistent for all donors being considered, the donor advocacy team at University of Texas Southwestern Medical Center developed the Independent Donor Ethical Assessment, a tool that may be useful to others in rendering donor advocacy. In addition, the tool may be modified as circumstances arise to improve donor advocacy and maintain uniformity in decision making. PMID:24919733

Choudhury, Devasmita; Jotterand, Fabrice; Casenave, Gerald; Smith-Morris, Carolyn; For The University Of Texas Southwestern Medical Center Donor Advocacy Team

2014-06-01

69

Antinuclear antibody detection by automated multiplex immunoassay in untreated patients at the time of diagnosis.  

PubMed

Fully automated multiplex immunoassays are increasingly used as first line screening for antinuclear antibodies. The diagnostic performance of such multiplex assays in untreated patients at the time of diagnosis has not been reported. Antinuclear antibodies were measured by indirect immunofluorescence (IIF) (dilution 1:160) and by BioPlex 2200 ANA screen (antibodies to dsDNA, chromatin, ribosomal protein, SSA-52, SSA-60, SSB, Sm, SmRNP, RNP-A, RNP-68, Scl-70, Jo-1, and centromere B) in 236 patients with a systemic rheumatic disease at the time of diagnosis, 149 blood donors, 139 patients with chronic fatigue syndrome (CFS), and 134 diseased controls. BioPlex ANA screen and IIF were positive in, respectively, 79% and 90% of patients with systemic lupus erythematosus (SLE), 60% and 60% with cutaneous lupus, 72% and 93% with systemic sclerosis (SSc), 100% and 100% with mixed connective tissue disease (MCTD), 89% and 56% with primary Sjögren's (SS) syndrome, 36% and 36% with polymyositis/dermatomyositis, 5.4% and 6% of blood donors, 7.2% and 3.6% of patients with CFS, and 11% and 18% of diseased controls. BioPlex test result interval specific likelihood ratios increased with increasing antibody concentration. The simultaneous presence of at least three antibodies by BioPlex was found in 35% of patients with SLE, 4% with SSc, 100% with MCTD, 64% with SS, 7% with inflammatory myopathy, 0.7% of CFS and diseased controls, and none of the blood donors. In conclusion, test result specific likelihood ratios and the presence of multiple autoantibodies help with the interpretation of data generated by multiplex immunoassays. PMID:22387973

Op De Beéck, Katrijn; Vermeersch, Pieter; Verschueren, Patrick; Westhovens, René; Mariën, Godelieve; Blockmans, Daniel; Bossuyt, Xavier

2012-12-01

70

Evaluation of Performance Parameters of a Membrane-Based Dot Immunoassay for Meningococcal Polysaccharide,  

National Technical Information Service (NTIS)

Increasingly, membrane-based enzyme immunoassays are being developed as the preferred solid-phase enzyme immunoassay format. We describe the rate kinetics of a polyvinylidene difluoride membrane-based dot immunoassay for meningococcal group A polysacchari...

J. D. Oprandy J. E. Sippel

1989-01-01

71

Homogeneous Immunoassays: Historical Perspective and Future Promise  

NASA Astrophysics Data System (ADS)

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.

Ullman, Edwin F.

1999-06-01

72

A duplexed microsphere-based fluorescent immunoassay.  

PubMed

Microsphere-based immunoassays are described for the simultaneous measurement of the clinically important drugs digoxin and theophylline. Competitive immunoassays were performed using haptenized microspheres and antibodies labeled with horseradish peroxidase. Enzyme-catalyzed reporter deposition (CARD) resulted in immunofluorescence signal amplification. Two encoding dyes were used to differentiate analytical signals from microspheres containing assays for the two analytes. An epifluorescence microscope and a CCD camera interfaced with a computer were utilized to measure fluorescence signals of individual microspheres. The microspheres from a duplexed assay were mounted on microscope slides as well as inserted into wells etched into the distal ends of optical imaging fibers. Fluorescence images from both formats were captured. In the experiments using microscope slides, the immunoassays were successfully duplexed and only marginal interferences at high analyte concentrations were observed. Preliminary results suggest that simultaneous determination of the two analytes using a fiber-based sensor-array format is feasible, but requires further development before precise quantitative analyses are possible. PMID:11401295

Szurdoki, F; Michael, K L; Walt, D R

2001-04-15

73

Retroperitoneal LESS donor nephrectomy.  

PubMed

Donor nephrectomy with laparo-endoscopic single site (LESS) surgery has been reported via the transperitoneal approach. We describe a novel technique of retroperitoneal donor nephrectomy using a single surgical incision in the groin, below the abdominal skin crease or "bikini line". The LESS groin incision offers superior cosmesis, while the retroperitoneal approach has distinct advantages, such as the ability to identify the renal vessels early. The new procedure has been performed in two obese patients (body mass index 32 and 33 kg/m2, respectively). The operative times were 4 and 5 hours, warm ischemic times 135 and 315 seconds, blood loss 100 and 250 mL, and hospitalization 3 and 2 days, respectively. Retroperitoneal LESS donor nephrectomy through a single, inconspicuous groin incision is feasible and safe. Further evaluation of the technique in a larger patient cohort is indicated. PMID:21044377

van der Merwe, A; Bachmann, A; Heyns, C F

2010-01-01

74

Immunoassay as a screening tool for industrial toxicants  

SciTech Connect

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.

Pierce, T.

1986-08-01

75

Laparoscopic donor nephrectomy  

Microsoft Academic Search

Background  Several large series of laparoscopic donor nephrectomy (LDN) have been published, largely focusing on immediate results and\\u000a short-term complications. The aim of this study was to examine the results of LDN and collect medium-term and long-term donor\\u000a followup.\\u000a \\u000a \\u000a \\u000a Methods  We examined the results of two surgeons who performed 500 consecutive LDNs from 1996 to 2005. Prospective databases were reviewed\\u000a for both

Edward H. Chin; David Hazzan; Daniel M. Herron; John N. Gaetano; Scott A. Ames; Jonathan S. Bromberg; Michael Edye

2007-01-01

76

Dialing for Donors  

ERIC Educational Resources Information Center

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…

Schaffhauser, Dian

2012-01-01

77

Donor insemination programmes with personal donors: issues of secrecy.  

PubMed

This study involved 46 recipients and donors in personal donor programmes interviewed anonymously by postal questionnaire and interview: 38% (30/80) of possible recipients responded. The total number of people told about the donor involvement ranged between two and 78, with no significant gender difference. Relationships had changed for half of the participants in the programmes with 75% reporting that they had developed a closer relationship and 25% reporting a deterioration. Contact between couples and donors was seen as being in the original role of family friend or relative rather than as donor. An equal proportion of recipients (63%) and donors (78%) agreed to the donor being identified to any offspring although this was qualified with regard to the age of the child. Reasons for identification were given as avoidance of family secrets and the rights of the child to have information concerning their conception. Those who did not agree said that the child was better off not knowing, or who wished to preserve donor anonymity. The donor group was more likely than the recipients to say that identification to the child was in the best interests of the social parents because it allowed all those involved to feel part of a single family group. It was found that for both recipients and donors, the advantages given for having a personal donor was openness within the relationship. For the recipients, this focused on knowledge of the donor background and, for related couples, having a common genetic relationship. For donors, the advantages given were: knowing the child's environment, having access to a child and the ability to choose recipients. A disadvantage for donors and recipients was the possibility of a change in the relationship and for donors an added disadvantage was having to share in the emotional stress of the treatment and negative outcomes. More men than women placed importance on having a donor with a similar genetic background. PMID:8981156

Adair, V A; Purdie, A

1996-11-01

78

Evaluating deceased donor registries: identifying predictive factors of donor designation.  

PubMed

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

2013-03-01

79

Outcomes of living donor liver transplantation using elderly donors  

PubMed Central

Purpose Living donor liver transplantation (LDLT) using elderly donors is increasing in frequency in response to organ shortage. However, elderly donor graft has been reported to negatively affect graft patency and patient survival. Methods We retrospectively reviewed the medical records of 604 patients who underwent LDLT at Seoul St. Mary's Hospital, The Catholic University of Korea between May 1999 and September 2012. Elderly donors were defined as those ?55 years of age. Here, we evaluate the survival differences and causes of death of recipients of elderly donor grafts. Results The overall mortality rate of the recipients was significantly higher in the elderly donor group (group A) than in the younger donor group (group B: 46.2% vs. 18.1%, P = 0.004). The survival length of group A was significantly shorter than that of group B (31.2 ± 31.3 and 51.4 ± 40.8 months, P = 0.014). The significantly common causes of death in group A were biliary (41.7%) and arterial complication (16.7%), and it was higher than those in group B (P = 0.000 and P = 0.043, respectively). Conclusion LDLT using elderly donors could induce more serious complications and higher mortality rates than those at using younger donors. As such, careful donor selection is needed, especially with regard to assessing the condition of potential elderly donor livers. Furthermore, a large-volume and multicenter study of complications and outcomes of LDLT using elderly donor liver is required.

Han, Jae Hyun; Na, Gun Hyung; Kim, Eun Young; Lee, Soo Ho; Hong, Tae Ho; Kim, Dong Goo

2014-01-01

80

Donor Matching for Allogenic Transplant  

MedlinePLUS

... often hard to find a good HLA match. Finding a match There are thousands of different combinations ... thousands of donors and recipients. The chances of finding an unrelated donor match improve each year, as ...

81

Laboratory and epidemiologic evaluation of an enzyme immunoassay for antibodies to HTLV-III  

SciTech Connect

The enzyme immunoassays (EIAs) for antibody to human T-cell lymphotropic virus type III (HTLV-III) were rapidly adopted for screening donated blood and plasma. To evaluate the significance of a positive EIA reaction, test performance was examined in a blood bank screening program. Specimens were tested by EIA, Western blot assay, and HTLV-III/lymphadenopathy-associated virus (LAV) culture. The EIA was positive in 0.25% of 67 190 blood donations. Specimens were categorized and 57.3% had low (weak) reactivity, 12.7% had moderate reactivity, and 30.0% had high reactivity. Highly reactive specimens were strongly associated with a positive Western blot or culture (86.7%) in contrast to moderately and weekly reactive specimens (1.9%). Twenty-five of 29 donors interviewed with a highly reactive EIA had risk factors for HTLV-III/LAV infection. Risk factors were not identified for 74 of 75 interviewed donors with specimens of lower reactivity. The minimum calculated specificity was 99.82%. The use of the HTLV-III EIA has virtually eliminated the use of blood and plasma for HTLV-III/LAV infected donors.

Ward, J.W.; Grindon, A.J.; Feorino, P.M.; Schable, C.; Parvin, M.; Allen, J.R.

1986-07-18

82

Enzyme immunoassays with special reference to ELISA techniques.  

PubMed Central

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.

Voller, A; Bartlett, A; Bidwell, D E

1978-01-01

83

Enzyme immunoassays with special reference to ELISA techniques  

Microsoft Academic Search

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.

A Voller; A Bartlett; D E Bidwell

1978-01-01

84

Validation of immunoassays for bioanalysis: a pharmaceutical industry perspective  

Microsoft Academic Search

Immunoassays are bioanalytical methods in which quantitation of the analyte depends on the reaction of an antigen (analyte) and an antibody. Although applicable to the analysis of both low molecular weight xenobiotic and macromolecular drugs, these procedures currently find most consistent application in the pharmaceutical industry to the quantitation of protein molecules. Immunoassays are also frequently applied in such important

J. W. A. Findlay; W. C. Smith; J. W. Lee; G. D. Nordblom; I. Das; B. S. DeSilva; M. N. Khan; R. R. Bowsher

2000-01-01

85

Novel One-step Immunoassays to Quantify ?-Synuclein  

PubMed Central

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

2012-01-01

86

Gliadin Detection in Food by Immunoassay  

NASA Astrophysics Data System (ADS)

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.

Grant, Gordon; Sporns, Peter; Hsieh, Y.-H. Peggy

87

Nanomaterial Labels in Electrochemical Immunosensors and Immunoassays  

SciTech Connect

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 nanomaterial–antibody-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.

Liu, Guodong; Lin, Yuehe

2007-12-15

88

Nanomaterial Labels in Electrochemical Immunosensors and Immunoassays  

PubMed Central

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 nanomaterial–antibody-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.

Liu, Guodong; Lin, Yuehe

2009-01-01

89

Fluorimetric immunoassay for multianalysis of aflatoxins.  

PubMed

A sensitive fluorimetric ELISA was developed for the analysis of aflatoxins. The assay was performed in a 384 microwell plate, wherein high specificity monoclonal antibody against AFM1 (mAb-AFM1) was used as capture antibody and FITC conjugated secondary antibody was used for detection and quantification of the analyte. The linear range of the immunoassay was found to be 6.25-50?pg/mL. AFM1 as low as 1?pg/mL was detected by this method with assay volume 40? ? L. The multi-analysis of different aflatoxins was also investigated in the microwell plate, based on the cross-reactivity (CR) approach. Real milk samples were tested along with certified reference material by standard addition method and recovery analysis was done. The mAb-AFM1 showed 23.2% CR with AFB1, 50% CR with respect to AFM2, and least CR towards AFG1 (<1%). Furthermore, mixture analysis of AFM2 and AFB1 was carried out at specific concentrations of AFM1. The advantages of this developed immunoassay are high sensitivity, high throughput, multianalyte detection, versatility, and ease of handling. PMID:24000318

Kanungo, Lizy; Bhand, Sunil

2013-01-01

90

Water-soluble conductive polymer homogeneous immunoassay (SOPHIA). A novel immunoassay capable of automation.  

PubMed

Conductive polymers are extensively conjugated macromolecules able to conduct electricity in their doped state and having a UV-visible spectrum which undergoes important chromatic modifications when subjected to pH changes or to oxido-reductive processes. This article describes a novel homogeneous immunoassay in which a water-soluble conductive polymer is used as the label. When antigen-antibody binding occurs, the local pH near the complex is modified. Such a pH change is in turn able to induce modifications in the absorbance at a characteristic wavelength of a conductive polymer covalently linked to either the antigen or the antibody. Consequently, the extent of tracer binding can be directly monitored by photometry during incubation. We present examples which validate the concept and exemplify its applicability in quantitative competitive immunoassays for human C-reactive protein and human serum albumin, as performed in a Cobas-Mira automated analyzer. PMID:8666835

Englebienne, P; Weiland, M

1996-05-27

91

[Serological and molecular genetic markers of hepatitis C virus in infected donors].  

PubMed

The frequency of hepatitis C virus (HCV) markers was determined in donors; the spectrum and activity of specific antibodies (anti-HCV), the distribution of virus genotypes, and HCV RNA concentrations were studied in virus carrier donors. The activity of antibodies in HCV RNA-negative donors was significantly lower than that in HCV RNA-positive donors (p < or = 0.001). There was a statistically significant difference in antibody activities in donors infected with genotype 1b as compared with those infected with genotype 3a (p < 0.001). However, no correlation was found between the concentration of a virus genome and the activity of specific antibodies. The risk for obtaining infected blood donations was determined during plasma screening by enzyme immunoassay (EIA). Our investigations have indicated that the frequency of serological window period donations is one case per 74750 test plasma units and that of HCV RNA-positive donations with low antibody positivity coefficients, which are frequently detectable as seronegative during screening for laboratory errors, is one case per 37375 test units. A combination of EIA and polymerase chain reaction has shown to minimize the risk of contamination of donor plasma with HCV markers. PMID:21260994

Zubkova, N V; Filatova, E V; Zubov, S V

2010-01-01

92

Environmental Immunoassays: Alternative Techniques for Soil and Water Analysis  

USGS Publications Warehouse

Analysis of soil and water samples for environmental studies and compliance testing can be formidable, time consuming, and costly. As a consequence, immunochemical techniques have become popular for environmental analysis because they are reliable, rapid, and cost effective. During the past 5 years, the use of immunoassays for environmental monitoring has increased substantially, and their use as an integral analytical tool in many environmental laboratories is now commonplace. This chapter will present the basic concept of immunoassays, recent advances in the development of immunochemical methods, and examples of successful applications of immunoassays in environmental analysis.

Aga, D. S.; Thurman, E. M.

1996-01-01

93

DETECTION OF ROTAVIRUS WITH A NEW POLYCLONAL ANTIBODY ENZYME IMMUNOASSAY (ROTAZYME 2) AND A COMMERCIAL LATEX AGGLUTINATION TEXT (ROTALEX): COMPARISON WITH A MONOCLONAL ANTIBODY ENZYME IMMUNOASSAY  

EPA Science Inventory

A total of 176 human fecal specimens were examined for the presence of rotavirus using four different assays: a monoclonal antibody enzyme immunoassay; the original polyclonal antibody enzyme immunoassay marketed by Abbott Laboratories, Chicago, IL (Rotazyme I); a modification of...

94

Immunoassay procedures for fiber optic sensors  

NASA Astrophysics Data System (ADS)

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.

Ligler, Frances S.

1988-04-01

95

External quality assessment schemes for immunoassays.  

PubMed

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

Sturgeon, Catharine

2013-01-01

96

Nanoparticles for Enhanced Sensitivity in Electrochemical Immunoassays  

SciTech Connect

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.

Lin, Yuehe; Wang, Jun; Wang, Hua; Wu, Hong; Tang, Zhiwen

2008-10-12

97

"Smart" mobile affinity matrix for microfluidic immunoassays.  

PubMed

There is a current need for simple methods for immobilizing biomolecules within microfluidic channels. Here, a technique is reported for reversibly immobilizing immunoassay components in a channel zone that can be simply controlled by integrated heating elements. Latex beads were modified with the temperature-responsive polymer poly(N-isopropylacrylamide)(PNIPAAm) and co-modified with biotinylated poly(ethylene glycol)(PEG). PNIPAAm undergoes a hydrophilic-to-hydrophobic transition when the temperature is raised above the lower critical solution temperature (LCST)( approximately 28 degrees C in the solutions used here). This reversible transition drives the aggregation and dis-aggregation of the modified beads in heated zones within poly(ethylene terephthalate)(PET) microchannels. Biotinylated monoclonal antibodies for the drug digoxin were bound via streptavidin to the biotin-PEG-coated beads. These antibody-functionalized beads were then reversibly immobilized by aggregation and hydrophobic adhesion to the surface of PET microfluidic channels in response to a thermal stimulus. The antibodies on the beads immobilized in the channel were shown to bind digoxin and a competitor fluorescent ligand from a flow stream in a quantitative competitive assay format that reported the digoxin concentration. The antibodies could be replenished for each immunoassay trial, using the reversible, temperature-controlled immobilization process. This technique allows reagent immobilization immediately prior to an analytical procedure, following the removal of previously utilized beads, guaranteeing fresh and active immobilized biomolecules. Furthermore, it provides a simple approach to multiplexing through the simultaneous or sequential injection of different antibody-coated bead species, potentially at multiple sites in the integrated device channels. PMID:15269814

Malmstadt, Noah; Hoffman, Allan S; Stayton, Patrick S

2004-08-01

98

New Developments and Applications of Immunoassay Technology (Abstract Only).  

National Technical Information Service (NTIS)

In addition to radio labelling, four types of labels are used in immunoassay technology: particles, enzymes, fluorophores and chemiluminophores. Of these labels, the lanthanide chelates, e.g., europium, can yield higher specific activities than commonly u...

F. Kohen G. Barnard

1989-01-01

99

Monoclonal Antibodies to Soybean Kunitz Trypsin Inhibitor and Immunoassay Methods.  

National Technical Information Service (NTIS)

The invention relates to and has among its objects the provision of hybridomas that produce and secrete monoclonal antibodies which are specific for soybean Kunitz trypsin inhibitor, and to immunoassay methods for the determination of active Kunitz trypsi...

D. L. Brandon A. H. Bates M. Friedman

1987-01-01

100

The design and applications of nanoparticle coated microspheres in immunoassays.  

PubMed

Nanoparticle coated microspheres are composed of two or more materials with a core/shell structure and exhibit unique abilities that allow amplification of trace targets in immunoassays. The preparation of nanoparticle coated microspheres can be accomplished using three main strategies: (1) in-situ, (2) ex-situ, and (3) hollow sphere methods. Antibodies or biomolecules can be immobilized on the surface of nanoparticle coated microspheres or hollow spheres to carry out detection of targets using surface-enhanced resonance spectroscopy (SERS), fluorescence, electrochemistry, and many others. Using these particles as antibody carriers in SERS-based immunoassays, broad dynamic range and low detection limits, and improved selectivity can be realized. By assistance of nanoparticle coated microspheres in immunoassays, improved sensitivity and selectivity has been realized. In this review, nanoparticle coated microsphere generation, recent applications, and future potential with respect to immunoassays are discussed. PMID:24730268

Lin, Huei-Shian; Carey, James R

2014-01-01

101

Diagnostic Assays Including Multiplexed Lateral Flow Immunoassays with Quantum DOTS.  

National Technical Information Service (NTIS)

Multiplexed lateral flow assays, related methods, and devices are disclosed which are capable of simultaneously detecting multiple analytes. The assays are preferably immunoassays and can be multiplexed spatially, spectrally, and both spatially and spectr...

J. L. Lambert A. M. Fisher

2005-01-01

102

Blood donor motivation : a phenomenological study of young male donors  

Microsoft Academic Search

The demand for blood products in Australia is projected to increase substantially in coming years. Yet population growth and population ageing will present challenges to blood donor recruitment and hence threaten the availability of adequate blood supplies for the future. Improving the retention of blood donors offers an opportunity to leverage this availability of blood products, and a focus on

Aleeza Morris

2011-01-01

103

Lanthanide-based time-resolved luminescence immunoassays  

Microsoft Academic Search

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

A. K. Hagan; T. Zuchner

2011-01-01

104

Multiplexed magnetic microsphere immunoassays for detection of pathogens in foods  

Microsoft Academic Search

Foodstuffs have traditionally been challenging matrices for conducting immunoassays. Proteins, carbohydrates, and other macromolecules\\u000a present in food matrices may interfere with both immunoassays and PCR-based tests, and removal of particulate matter may also\\u000a prove challenging prior to analyses. This has been found true when testing for bacterial contamination of foods using the\\u000a standard polystyrene microspheres utilized with Luminex flow cytometers.

Jason S. Kim; Chris R. Taitt; Frances S. Ligler; George P. Anderson

2010-01-01

105

Capillary Electrophoresis-Based Immunoassays: Principles & Quantitative Applications  

PubMed Central

The use of capillary electrophoresis as a tool to conduct immunoassays has been an area of increasing interest over the last decade. This approach combines the efficiency, small sample requirements, and relatively high speed of CE with the selectivity of antibodies as binding agents. This review examines the various assay formats and detection modes that have been reported for these assays, along with some representative applications. Most CE immunoassays in the past have employed homogeneous methods in which the sample and reagents are allowed to react in solution. These homogeneous methods have been conducted as both competitive binding immunoassays and as non-competitive binding immunoassays. Fluorescent labels are most commonly used for detection in these assays, but enzyme labels have also been utilized for such work. Some additional work has been performed in CE immunoassays with heterogeneous methods in which either antibodies or an analog of the analyte is immobilized to a solid support. These heterogeneous methods can be used for the selective isolation of analytes prior to their separation by CE or to remove a given species from a sample/reagent mixture prior to analysis by CE. These CE immunoassays can be used with a variety of detection modes, such as fluorescence, UV/visible absorbance, chemiluminescence, electrochemical measurements, mass spectrometry, and surface plasmon resonance.

Moser, Annette C.; Hage, David S.

2013-01-01

106

Motivation of voluntary plasmapheresis donors.  

PubMed

A totally voluntary plasmapheresis program recruits 900 individual donors per year at a cancer institute, where 500 to 900 units of platelets are transfused each month. Staff and donors use a film and brochures to recruit donors from the local community. Television and radio spots, with donor recognition pins, certificates, receptions, and picnics are utilized. Donor motivation was studied by use of: 1) California Psychological Inventory--measures a variety of "normal" personality traits; 2) Study of values--measures theoretical, economic, aesthetic, social, political, religious values; 3) Internal-External Control Scale--measures degree to which a person blames self vs. external events for what happens to him; 4) Faith in People Scale--measures individual's confidence in his fellow man; 5) Anomia Scale--measure of feelings of self-to-others alienation; 6) Mach IV Scale--measure of persons tendency to manipulate others; and 7) Biographical Data Form. Results are presented for 25 male donor subjects studied, as they compare with normative data for the scales used. Donors appeared to have the same traits as do the general population, but appeared lower in Machiavellianism than non-plasmapheresis donors. Prospective study plans include additional subjects to provide appropriate control groups. PMID:951736

Cataldo, J F; Cohen, E; Morganti, J B

1976-01-01

107

The Dirt on the Donors.  

ERIC Educational Resources Information Center

A discussion of donor records in college and university fund-raising programs looks at a variety of issues, including who sees them (administrators, donors, volunteers, and members of the legal profession), how access to them is controlled, and what is kept in them. Suggestions are offered for managing such records, and the experiences of a number…

Walker, Mary Margaret

1996-01-01

108

Trends in transfusion transmitted infections among replacement blood donors in karachi, pakistan.  

PubMed

Objective: To determine the prevalence of Hepatitis-B, Hepatitis-C and Human Immunodeficiency infections in replacement blood donors. Materials and Methods: From January 2004 to December 2011, 108,598 apparently healthy donors donated blood at our Blood Bank. Screening was done by Microparticle Enzyme Immuno Assay (MEIA) method on Axsym System (Abbott Diagnostic, USA) and in year 2011 by Chemiluminescent Immunoassay (CIA) method on Architect i2000 (Abbott Diagnostic, USA). From 2010 onward, HIV reactive donors were advised for confirmatory tests and reported back with the results. Results: Of the 108,598 total donors, 108,393 (99.8%) were replacement donors with a mean age of 28.92 (17-55) years. Of this, only 164 (0.15%) were females. Among the replacement donors, 4,906 (4.5%) were found to be reactive for Hepatitis-B, C and Human Immunodeficiency Virus. All the reactive patients, except one, were males. HbsAg was positive in 2,068 (1.90%) and anti-HCV in 2832 (2.61%) donors, while 111 (0.10%) were positive for Human Immunodeficiency Virus. Co-infectivity was observed in 103 (0.09%) cases. The prevalence appeared to be higher in younger age group (17-30 yrs). Only 16.6% cases should be patients returned with results of the confirmatory tests for HIV and were found positive. Conclusion: Hepatitis-B and C sero-prevalence in our series of replacement donors appears high compared to most studies from neighboring countries and relatively low in comparison to earlier studies from Pakistan. Prevalence of HIV, however, appears low and turn out of HIV positive cases for confirmatory tests is low. Conflict of interest:None declared. PMID:24385780

Irfan, Syed Mohammad; Uddin, Jamal; Zaheer, Hasan Abbas; Sultan, Sadia; Baig, Amjad

2013-06-01

109

Toxicological detection of pholcodine and its metabolites in urine and hair using radio immunoassay, fluorescence polarisation immunoassay, enzyme immunoassay, and gas chromatography-mass spectrometry.  

PubMed

Pholcodine (3-O-(2'-morpholinoethyl)-morphine) is used in many countries as an antitussive without analgesic or addictive properties. It is of forensic relevance that pholcodine interferes with opiate immunoassays. In this paper a gas chromatographic-mass spectrometric (GC-MS) procedure for the precise and sensitive detection of pholcodine and its metabolites in urine and hair, after acid hydrolysis, extraction and acetylation, is presented. Furthermore, detection of pholcodine using radio immunoassay (RIA), fluorescence polarisation immunoassay (FPIA) and enzyme immunoassay (EIA) for opiates is described. Using GC-MS, unmodified pholcodine could be detected in urine samples 4-7 weeks after ingestion of a single therapeutic dose of 50mg of pholcodine, the desmorpholinohydroxy metabolite for 1-2 weeks and the other metabolites (nor-, nordesmorpholinohydroxy-, hydroxy-, oxo- and noroxo-pholcodine) only during the first few hours. Morphine could also be detected in urine samples for the first few days. It was however mainly formed artificially during acid hydrolysis and only in trace amounts by metabolism. All the immunoassays tested gave positive results in urine samples during the first week taking the cut-off values recommended by the manufacturer into consideration. If values between the cut-off and the detection limit were taken into consideration, RIA and FPIA gave positive results for 2-4 weeks and EIA up to 2 weeks. Pholcodine could also be detected by RIA and GC-MS in samples of head hair clipped 10 weeks after ingestion of 50mg and in daily shaved samples of beard hair over a period of three weeks after ingestion of three doses of 60mg. It can be concluded that the widely used immunoassays for opiates show positive results in urine and hair samples for a long time after ingestion of the non-opioid pholcodine and that these results can be confirmed by the GC-MS procedure described in this paper. PMID:11453092

Maurer, H H; Fritz, C F

1990-12-01

110

Grandparent donors in paediatric renal transplantation  

Microsoft Academic Search

The outcome of transplantation from grandparent donors in comparison with parental donors in paediatric renal transplantation was evaluated in 53 living related donor (LRD) transplantations performed between January 1996 and August 2003. The donor in 13 cases (25%) was a grandparent (Gpar group), and the remaining donors formed the parent group (Par group). The median age of recipients in the

Catherine M. Simpson; Steven J. McTaggart; Jonathan A. C. Sterne; Rowan G. Walker; Harley R. Powell; Colin L. Jones

2005-01-01

111

[Liver transplantation and living donors].  

PubMed

LIVER SPLITTING: Classically, cadaver livers are split ex situ to provide two grafts for transplantation. This procedure could be performed in situ, limiting the duration of the operation and improving recovery of liver function. LIVING RELATED DONORS: Living donor liver transplantation is a well established technique in children. Donor mortality is nil and morbidity very acceptable. For adults, the results have been less satisfactory with increasing risk for the recipient, with biliary and venous problems due to the "small-for-size" implant. ORGAN HARVESTING: The left lobe, classically used for children, can also be grafted into adults, but under certain restrictive conditions. If the donor's residual liver volume is below 0.8% of the total body mass, the biological alterations remain limited and transient. EMERGENCY TRANSPLANTATIONS: Liver transplantations using a living donor can save critically ill patients with a life expectancy of less than 3 months. Remarkable survival rates have been achieved. PMID:11577581

Campan, P

2001-09-01

112

Seroepidemiology of infection with Toxoplasma gondii in healthy blood donors of Durango, Mexico  

PubMed Central

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: 1.45–10.01). The age group of 45–60 years showed a significantly higher frequency of T. gondii infection than the group of 25–34 years (p = 0.02). Blood donors without education had a significantly higher frequency of infection (15.8%) than those with 13–19 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

2007-01-01

113

Multiplex lateral flow immunoassay for mycotoxin determination.  

PubMed

A new lateral flow immunoassay (LFA) is proposed for qualitative and/or semiquantitative determination of aflatoxin B1 (AFB1), zearalenone (ZEA), deoxynivalenol (DON), and their analogues (AFs, ZEAs, DONs) in cereal samples. Each of the mycotoxin specific antibody was class specific and there was no cross reactivity to other groups of compounds. The visual limits of detection (vLOD) of the strip were 0.03, 1.6, and 10 ?g/kg for AFB1, ZEA and DON, respectively. The calculated limits of detection (cLOD) were 0.05, 1, and 3 ?g/kg, respectively. Meanwhile the cutoff values were achieved at 1, 50, and 60 ?g/kg for AFB1, ZEA and DON, respectively. Recoveries ranged from 80% to 122% and RSD from 5% to 20%. Both the vLOD and cLOD for the three mycotoxins were lower than the EU maximum levels. Analysis of naturally contaminated maize samples resulted in a good agreement between the multiplex LFA and LC-MS/MS (100% for DONs and AFs, and 81% for ZEAs). Careful analysis of the results further explained the general overestimation of LFA compared to chromatographic methods for quantification of mycotoxins. PMID:24745689

Song, Suquan; Liu, Na; Zhao, Zhiyong; Njumbe Ediage, Emmanuel; Wu, Songling; Sun, Changpo; De Saeger, Sarah; Wu, Aibo

2014-05-20

114

The mystifying nomenclature of cardiac troponin immunoassays.  

PubMed

Abstract The laboratory assessment of cardiospecific troponins(s) represents the cornerstone for the diagnosis of acute coronary syndrome (ACS). Although troponin immunoassays are classified according to either analytical imprecision or percentage of measurable values in a presumably healthy population, it is rather clear that the nomenclature of commercial methods according to these systems of classification carries several drawbacks. The leading problems in classification according to imprecision are represented by the arbitrarity of optimal imprecision threshold, the uncertain correspondence between analytical performance and clinical outcomes and the improper use of terms, which has also been magnified by the lack of specific focus on this topic by regulating bodies such as the US Food and Drug Administration (FDA) and the European Union. Additional issues emerging from classification according to percentage of measurable values include the characterization of healthy population, the variation of values according to age, gender and race, as well as the influence of comorbidities. Considering that what really matters from a clinical standpoint is the clinical performance of the assay rather than the claimed analytical characteristics, it seems reasonable at this point in time to introduce a paradigm shift and gradually abandon the former analytical classification in favour of a different approach, preferable based on clinical outcomes. PMID:24588414

Lippi, Giuseppe

2014-06-01

115

Vertical flow immunoassay (VFA) biosensor for a rapid one-step immunoassay.  

PubMed

A highly rapid, one-step immunoassay of high sensitivity C-reactive protein (hsCRP) using a biosensor with a vertical flow immunoassay (VFA) was developed. The VFA biosensor was primarily composed of a sample pad, conjugate pad, FTH film and nitrocellulose (NC) membrane, which were all vertically stacked upon one another. Anti-hsCRP and secondary antibodies were consecutively immobilized on the NC membrane at the position below the holes. Gold nanoparticles (AuNPs) conjugated with another anti-hsCRP antibody were encapsulated in the conjugation pad. Various assay conditions, including the size of the hole and the sample volume, were optimized. Under optimized conditions, hsCRP concentrations from 0.01 to 10 ?g mL(-1) were detected within 2 min. In comparison with a lateral flow assay (LFA) system, the VFA sensor showed a gradual increase of signal in a concentration-dependent manner without a hook effect in the tested range. PMID:23303290

Oh, Young Kyoung; Joung, Hyou-Arm; Kim, Sanghyo; Kim, Min-Gon

2013-03-01

116

Minimally invasive donor nephrectomy: innovations.  

PubMed

From open surgery to laparoscopic surgery, there has been an evolution in the surgical technique for live donor nephrectomy which goes beyond patient comfort. As a unique operation where the margin for error is nearly nil, and where the patient is essentially harmed for an altruistic goal, ensuring the best possible result is vital. Additionally, as the morbidity of the operation decreases, there is a theoretical increase in the donor pool. In this review, the latest techniques for minimally invasive live donor nephrectomy are covered, including new approaches such as laparoendoscopic single-site surgery, natural orifice surgery, and new tools such as robotics. PMID:24338815

Caso, Jorge R

2014-01-01

117

SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION PROGRAM DEMONSTRATION PLAN FOR WESTINGHOUSE BIO-ANALYTIC SYSTEMS PENTACHLOROPHENOL IMMUNOASSAYS  

EPA Science Inventory

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...

118

SUPERFUND INNOVATIVE TECHNOLOGY EVALUATION (SITE) REPORT FOR THE WESTINGHOUSE BIOANALYTICAL SYSTEMS PENTACHLOROPHENOL (PCP) IMMUNOASSAYS  

EPA Science Inventory

The results of the demonstration of two Westinghouse Bio-Analytic Systems (WBAS) immunoassay technologies are described in this report. The immunoassays measure parts per billion concentrations of pentachlorophenol in environmental water samples. The study was conducted under the...

119

Immunoassays, Assay Methods, Antibodies and Method of Creating Antibodies for Detecting FGF-23.  

National Technical Information Service (NTIS)

Immunoassays, assay methods, antibodies and methods of producing antibodies for the detection of fibroblast growth factor-23 (FGF-23). The immunoassay and assay method preferably comprise a non-competitive, sandwich-type assay utilizing a first bound anti...

H. Jueppner J. Lavigne R. Zahradnik

2002-01-01

120

The Effects of Sample Matrices on Immunoassays to Detect Microcystin-LR in Water  

EPA Science Inventory

Abstract: Immunoassays are widely used biochemical techniques to detect microcystins in environmental samples. The use of immunoassays for the detection of microcystins is vulnerable to matrix components and other interferents. This study is an evaluation of the effects of interf...

121

Being a Living Donor: Risks  

MedlinePLUS

... surgical risks and long term complications: Long-Term Organ Specific Donor Complications Kidney Hypertension Kidney failure Proteinuria ... your recipient may face surgical complications. The transplanted organ may not work right away. There is also ...

122

Ambivalence in living liver donors.  

PubMed

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

2011-10-01

123

Quality assurance in immunoassay performance--comparison of different enzyme immunoassays for the determination of caffeine in consumer products.  

PubMed

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

Grandke, Julia; Oberleitner, Lidia; Resch-Genger, Ute; Garbe, Leif-Alexander; Schneider, Rudolf J

2013-02-01

124

Motivations for Giving of Alumni Donors, Lapsed Donors and Non-Donors: Implications for Christian Higher Education  

ERIC Educational Resources Information Center

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 sample…

Rugano, Emilio Kariuki

2011-01-01

125

Automated liquid operation method for microfluidic heterogeneous immunoassay.  

PubMed

In this work, an automated liquid operation method for multistep heterogeneous immunoassay toward point of care testing (POCT) was proposed. A miniaturized peristaltic pump was developed to control the flow direction, flow time and flow rate in the microliter range according to a program. The peristaltic pump has the advantages of simple structure, small size, low cost, and easy to build and use. By coupling the peristaltic pump with an antibody-coated capillary and a reagent-preloaded cartridge, the complicated liquid handling operation for heterogeneous immunoassay, including sample metering and introduction, multistep reagent introduction and rinsing, could be triggered by an action and accomplished automatically in 12 min. The analytical performance of the present immunoassay system was demonstrated in the measurement of human IgG with fluorescence detection. A detection limit of 0.68 ?g/mL IgG and a dynamic range of 2-300 ?g/mL were obtained. PMID:23597987

Yi, Hui; Pan, Jian-Zhang; Shi, Xiao-Tong; Fang, Qun

2013-02-15

126

Protein microchips : use for immunoassay and enzymatic reactions.  

SciTech Connect

Different proteins such as antibodies, antigens, and enzymes were immobilized within the 100 x 100 x 20-{mu}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 antigen-antibody interactions within the gel. Protein microchips were used in immunoassays for detection of antigens or antibodies, as well as to carry out enzymatic reactions and to measure their kinetics in the absence or presence of an inhibitor. A protein microchip can be used several times in different immunoassays and enzymatic kinetic measurements.

Arenkov, P.; Kukhtin, A.; Gemmell, A.; Voloschuk, S.; Chupeeva, V.; Mirzabekov, A.; Biochip Technology Center; Russian Academy of Sciences

2000-02-15

127

Chylous ascites secondary to laparoscopic donor nephrectomy  

Microsoft Academic Search

Live donor renal transplantation offers many significant advantages over cadaveric donor transplantation. Yet living donation continues to be underused, accounting for less than 30% of all donor renal transplants. In an attempt to remove the disincentives to live donation, Ratner et al. developed laparoscopic donor nephrectomy (LDN). LDN is gaining acceptance in the transplant community. The overriding concern must always

Stephen F Shafizadeh; Patrick P Daily; Prabhakar Baliga; Jeffrey Rogers; G. Mark Baillie; P. R Rajagopolan; Kenneth D Chavin

2002-01-01

128

Philanthropic Motivations of Community College Donors  

Microsoft Academic Search

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

Linnie S. Carter; Molly H. Duggan

2010-01-01

129

Philanthropic Motivations of Community College Donors  

ERIC Educational Resources Information Center

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…

Carter, Linnie S.; Duggan, Molly H.

2011-01-01

130

Concentration gradient immunoassay. 1. An immunoassay based on interdiffusion and surface binding in a microchannel.  

PubMed

We describe a novel microfluidic immunoassay method based on the diffusion of a small-molecule analyte into a parallel-flowing stream containing a 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, A.; Kamholz, A. E.; Hawkins, K. R.; Munson, M. S.; Schilling, E. A.; Weigl, B. H.; Yager, P. Nat. Biotechnol. 2001, 19, 461-465.), this antibody occupancy gradient is interrogated by a sensor surface coated with a functional analogue 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/s, the assays are complete within 10 min. 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. PMID:17437332

Nelson, Kjell E; Foley, Jennifer O; Yager, Paul

2007-05-15

131

Estimation of sensitivity and specificity of several Trypanosoma cruzi antibody assays in blood donors in Argentina  

PubMed Central

BACKGROUND The absence of a gold standard test for Trypanosoma cruzi antibodies represents a problem not only for the evaluation of screening tests, but also for appropriate blood donor counseling. The aim of this study was to estimate the sensitivity and specificity of multiple blood donor screening tests for T. cruzi antibodies in Argentina. STUDY DESIGN AND METHODS From June 2006 to March 2007 a sample of 1455 blood donors was recruited from two blood banks in Chaco province, an area of Argentina with highly endemic T. cruzi infection. Samples were tested by three epimastigote lysate enzyme immunoassays (EIAs), one recombinant antigen EIA, two indirect hemagglutination assay (IHA) tests, a particle agglutination assay (PA), and a research trans-sialidase inhibition assay (TIA). Sensitivity and specificity were estimated using latent class analysis (LCA). RESULTS LCA estimated the consensus prevalence of T. cruzi infection at 24.5%. Interassay correlation was higher among the four EIA tests and TIA compared to IHA tests. Assay sensitivities varied from 96 to 99.7 for different EIAs, 91% for TIA, 84% for PA, and 66 to 74% for IHA tests. Relative to the LCA, assay specificities were from 96% to almost 100%. CONCLUSION Based on the comparison of several tests in a large population from an endemic area for T. cruzi infection, our data showed an adequate sensitivity for EIA tests in contrast to PA and IHA assays. The latter tests should no longer be used for blood donor screening.

Remesar, Mirta C.; Gamba, Cecilia; Colaianni, Ivana F.; Puppo, Monica; Sartor, Paula A.; Murphy, Edward L.; Neilands, Torsten B.; Ridolfi, Maria A.; Leguizamon, M. Susana; Kuperman, Silvina; del Pozo, Ana E.

2010-01-01

132

Marked digoxin-like immunoreactive factor interference with an enzyme immunoassay.  

PubMed

A case in which digoxin-like immunoreactive factors (DLIF) interfered with an enzyme immunoassay in a patient with renal insufficiency is reported. A 79-year-old woman was found to have a serum digoxin concentration (SDC) determined by enzyme immunoassay of 5.0 ng/ml. Although all subsequent SDC determined by the enzyme immunoassay system were elevated, identical samples run on a fluorescence polarization immunoassay revealed SDC within the therapeutic range. Marked DLIF-related assay interference has been reported to occur with some digoxin assays; however, the enzyme immunoassay methods have never been reported to cross-react to the magnitude seen in this case. PMID:3063480

Karboski, J A; Godley, P J; Frohna, P A; Horton, M W; Reitmeyer, W J

1988-09-01

133

Toxicological detection of pholcodine and its metabolites in urine and hair using radio immunoassay, fluorescence polarisation immunoassay, enzyme immunoassay and gas chromatography-mass spectrometry  

Microsoft Academic Search

Summary Pholcodine (3-O-(2'-morpholinoethyl)-morphine) is used in many countries as an antitussive without analgesic or addictive properties. It is of forensic relevance that pholcodine interferes with opiate immunoassays. In this paper a gas chromatographic-mass spectrometric (GC-MS) procedure for the precise and sensitive detection of pholcodine and its metabolites in urine and hair, after acid hydrolysis, extraction and acetylation, is presented. Furthermore,

Hans H. Maurer; Christian F. Fritz

1990-01-01

134

Dimethylamylamine: a drug causing positive immunoassay results for amphetamines.  

PubMed

The Department of Defense (DoD) operates six forensic urine drug-testing laboratories that screen close to 5 million urine samples for amphetamines yearly. Recently, the DoD laboratories have observed a significant decrease in the confirmation rates for amphetamines because of specimens screening positive by two separate immunoassays and confirming negative by gas chromatography-mass spectrometry (GC-MS). Previous studies conducted by the Division of Forensic Toxicology, Armed Force Institute of Pathology (AFIP) utilizing a GC-MS basic drug screen and a designer drug screen revealed no common compound or compound classes as to the cause of the immunoassay-positive results. Additional information obtained from an immunoassay vendor suggested the anorectic compound dimethylamylamine (DMAA) may be the cause of the false-positive screens. An additional 134 false-positive samples were received and analyzed using liquid chromatography-tandem mass spectrometry (LC-MS-MS) for DMAA. LC-MS-MS analysis revealed the presence of DMAA in 92.3% of the false-positive samples at a concentration of approximately 6.0 mg/L DMAA, causing a positive screen on both immunoassay kits. PMID:21439156

Vorce, Shawn P; Holler, Justin M; Cawrse, Brian M; Magluilo, Joseph

2011-04-01

135

A compact immunoassay platform based on a multicapillary glass plate.  

PubMed

A highly sensitive, rapid immunoassay performed in the multi-channels of a micro-well array consisting of a multicapillary glass plate (MCP) and a polydimethylsiloxane (PDMS) slide is described. The micro-dimensions and large surface area of the MCP permitted the diffusion distance to be decreased and the reaction efficiency to be increased. To confirm the concept of the method, human immunoglobulin A (h-IgA) was measured using both the proposed immunoassay system and the traditional 96-well plate method. The proposed method resulted in a 1/5-fold decrease of immunoassay time, and a 1/56-fold cut in reagent consumption with a 0.05 ng/mL of limit of detection (LOD) for IgA. The method was also applied to saliva samples obtained from healthy volunteers. The results correlated well to those obtained by the 96-well plate method. The method has the potential for use in disease diagnostic or on-site immunoassays. PMID:24859022

Xue, Shuhua; Zeng, Hulie; Yang, Jianmin; Nakajima, Hizuru; Uchiyama, Katsumi

2014-01-01

136

Development of a Fluorescence Polarization Immunoassay for Polycyclic Aromatic Hydrocarbons  

Microsoft Academic Search

A fluorescence polarization immunoassay for detection of polycyclic aromatic hydrocarbons (PAHs) was developed. Fluorescein?labeled tracers based on different PAHs were synthesized and studied in order to achieve a high sensitivity using both monoclonal and polyclonal antibodies. The application of different combinations of antibody tracer pairs allows to separately determine groups of small and large PAHs or to realize a class?specific

Irina Yu Goryacheva; Sergei A. Eremin; Ekaterina A. Shutaleva; Miloslav Suchanek; Reinhard Niessner; Dietmar Knopp

2007-01-01

137

A Compact Immunoassay Platform Based on a Multicapillary Glass Plate  

PubMed Central

A highly sensitive, rapid immunoassay performed in the multi-channels of a micro-well array consisting of a multicapillary glass plate (MCP) and a polydimethylsiloxane (PDMS) slide is described. The micro-dimensions and large surface area of the MCP permitted the diffusion distance to be decreased and the reaction efficiency to be increased. To confirm the concept of the method, human immunoglobulin A (h-IgA) was measured using both the proposed immunoassay system and the traditional 96-well plate method. The proposed method resulted in a 1/5-fold decrease of immunoassay time, and a 1/56-fold cut in reagent consumption with a 0.05 ng/mL of limit of detection (LOD) for IgA. The method was also applied to saliva samples obtained from healthy volunteers. The results correlated well to those obtained by the 96-well plate method. The method has the potential for use in disease diagnostic or on-site immunoassays.

Xue, Shuhua; Zeng, Hulie; Yang, Jianmin; Nakajima, Hizuru; Uchiyama, Katsumi

2014-01-01

138

Galactomannan enzymatic immunoassay cross-reactivity caused by Prototheca species.  

PubMed

We report a reactive Aspergillus galactomannan enzymatic immunoassay against the serum of a patient with invasive Prototheca zopfii infection. Analysis of the supernatants of suspensions of P. zopfii and other Prototheca isolates revealed positive results as well. These data suggest cross-reactivity with the serum Aspergillus galactomannan assay in invasive protothecosis. PMID:22837317

Van den Bossche, D; De Bel, A; Hendrickx, M; De Becker, A; Jacobs, R; Naessens, A; Piérard, D

2012-10-01

139

Galactomannan Enzymatic Immunoassay Cross-Reactivity Caused by Prototheca Species  

PubMed Central

We report a reactive Aspergillus galactomannan enzymatic immunoassay against the serum of a patient with invasive Prototheca zopfii infection. Analysis of the supernatants of suspensions of P. zopfii and other Prototheca isolates revealed positive results as well. These data suggest cross-reactivity with the serum Aspergillus galactomannan assay in invasive protothecosis.

Van den Bossche, D.; Hendrickx, M.; De Becker, A.; Jacobs, R.; Naessens, A.; Pierard, D.

2012-01-01

140

A portable analyzer for pouch-actuated, immunoassay cassettes  

Microsoft Academic Search

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

141

Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates  

DOEpatents

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)

1997-01-01

142

Manipulation of Dispersed Magnetic Beads for On-Chip Immunoassay  

NASA Astrophysics Data System (ADS)

To provide a simple and low-cost mobile immunoassay platform, a test chip on which dispersed magnetic beads are manipulated was designed and fabricated by a 180 nm standard complementary metal--oxide--semiconductor (CMOS) process. In preliminary experiments, beads that have a diameter of 2.8 ?m were successfully manipulated and their motion were captured and analyzed. Then, an immunoassay was conducted on the chip. First, the nonspecific binding of hydrophilic beads coated with an antibody was compared with that of hydrophobic beads that were used for the preliminary experiments. Next, comparison of an immunoassay of mouse IgG with a control assay and a test on the feasibility of the blocking process were conducted simultaneously. The beads coated with the antibody were successfully immobilized onto the chip surface in the presence of the target antigen, which was checked through bead manipulation. This indicates that an immunoassay on an inexpensive CMOS chip is feasible using an affordable amount of driving current.

Ishikawa, Tomohiro; Lee, Jaesung; Miyake, Ryo

2012-04-01

143

Protein Microchips: Use for Immunoassay and Enzymatic Reactions  

Microsoft Academic Search

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 antigen–antibody interactions within the gel. Protein microchips were used in immunoassays for detection

Pavel Arenkov; Alexander Kukhtin; Anne Gemmell; Sergey Voloshchuk; Valentina Chupeeva; Andrei Mirzabekov

2000-01-01

144

Magnetic Beads-based Bioelectrochemical Immunoassay of Polycyclic Aromatic Hydrocarbons  

SciTech Connect

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

2007-07-01

145

Ganglioside–liposome immunoassay for the detection of botulinum toxin  

Microsoft Academic Search

A rapid and highly sensitive receptor immunoassay for botulinum toxin (BT) has been developed using ganglioside-incorporated liposomes. Botulism outbreaks are relatively rare, but their results can be very severe, usually leading to death from respiratory failure. To exert their toxicity, the biological toxins must first bind to receptors on the cell surface, and the trisialoganglioside GT1b has been identified as

Soohyoun Ahn-Yoon; Thomas R. DeCory; Richard A. Durst

2004-01-01

146

Highly sensitive homogenous chemiluminescence immunoassay using gold nanoparticles as label.  

PubMed

Homogeneous immunoassay is becoming more and more attractive for modern medical diagnosis because it is superior to heterogeneous immunoassay in sample and reagent consumption, analysis time, portability and disposability. Herein, a universal platform for homogeneous immunoassay, using human immunoglobulin G (IgG) as a model analyte, has been developed. This assay relies upon the catalytic activity of gold nanoparticles (AuNPs) on luminol-AgNO3 chemiluminescence (CL) reaction. The immunoreaction of antigen and antibody can induce the aggregation of antibody-functionalized AuNPs, and after aggregation the catalytic activity of AuNPs on luminol-AgNO3 CL reaction is greatly enhanced. Without any separation steps, a CL signal is generated upon addition of a trigger solution, and the CL intensity is directly correlated to the quantity of IgG. The detection limit of IgG was estimated to be as low as 3pg/mL, and the sensitivity was better than that of the reported AuNPs-based CL immunoassay for IgG. PMID:24835732

Luo, Jing; Cui, Xiang; Liu, Wei; Li, Baoxin

2014-10-15

147

Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates  

DOEpatents

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.

Callstrom, M.R.; Bednarski, M.D.; Gruber, P.R.

1997-11-25

148

Lateral flow colloidal gold-based immunoassay for pesticide.  

PubMed

In recent years, immunochromatographic lateral flow test strips are used as a popular diagnostic tool. There are two formats (noncompetitive and competitive) in gold-based immunoassay. Noncompetitive gold-based immunoassay also called sandwich assay is applied for the detection of large molecular mass. For small molecular mass such as pesticide, competitive format of lateral flow colloidal gold-based immunoassay is described in this chapter. The preparation of gold colloidal and the conjugation between antibody and gold colloidal are described. Hi-flow plus nitrocellulose membranes are separately coated with goat anti-rabbit IgG (control line) and hapten-OVA conjugate (test line). Thus, the degree of intensity of color of the test line is the reverse of the concentration of pesticide in the sample and the visual result is immediately observable. Colloidal gold-based immunoassay can also be applied for multianalysis in one test strip if the detected targets show different physico-chemical properties and their haptens show great differences in chemical structure. PMID:19159101

Wang, Shuo; Zhang, Can; Zhang, Yan

2009-01-01

149

New oxygen donors in silicon  

NASA Astrophysics Data System (ADS)

Oxygen donor traps and oxygen-related precipitates are investigated by deep level transient spectroscopy (DLTS) and transmission electron microscopy (TEM). The so-called New Donors (ND's) occur after thermal treatments in the temperature range of 650 ° 800 ° C. They have a continuous distribution of trap states with respect to energy in the band gap of Si. The concentration of the trap states increases towards the conduction band edge. The precipitates observed are mainly platelets and ribbon-like defects. The formation and annihilation kinetics of ND traps and oxygen-related precipitates are correlated. An “SiO x Interface Model” is proposed to explain the origin and the donor-like behavior of the ND traps. The ND trap spectrum is composed of two different types of trap states: interface states at the surface of precipitates and bound states in the Coulombic wells of a fixed positive charge which is located in the SiO x precipitates.

Pensl, G.; Schulz, M.; Hölzlein, K.; Bergholz, W.; Hutchison, J. L.

1989-01-01

150

Rapid homogenous time-resolved fluorescence (HTRF) immunoassay for anthrax detection.  

PubMed

Infection with Bacillus anthracsis spores induces an acute anthrax disease that can cause casualties and death in untreated cases. Thus rapid diagnosis of anthrax at early stage of the disease is essential to allow an effective treatment. Here we present the development of rapid and sensitive homogenous time-resolved fluorescence (HTRF) immunoassays based on the energy transfer process of europium cryptate (EuK) donor to AlexaFluor647 acceptor. The energy transfer process is limited to d?donor and acceptor antibodies to the analyte would result in positive signal. HTRF assay was developed for the detection of the bacterial Protective Antigen (PA) toxin, a serological marker that correlates with bacteremia in infected hosts, using two monoclonal anti-PA antibodies that specifically recognize two different epitopes on the PA molecule. The assay was sensitive enabling detection of 2 ng/ml PA in the serum of B. anthracsis-infected rabbits in only 15 min assay. Additionally, HTRF assay was developed for the detection of bacterial spores using polyclonal anti-spore antibodies that recognize many epitopes on the bacterial surface. The assay enabled the detection of 2?×?10(6) spores/ml in 30 min assay and was specific, showing no cross reactivity with closely related non-virulent bacillus cereus strain. This study describes the use of the HTRF assay for the detection of both singled-epitope (proteins) and multi-epitope (particles) as rapid, simple and sensitive method that can be used at the time that fast results are needed to allow an effective medical care. PMID:24515915

Cohen, Noam; Mechaly, Adva; Mazor, Ohad; Fisher, Morly; Zahavy, Eran

2014-05-01

151

Donor Specific Antibodies after Transplantation  

PubMed Central

The detection of donor specific antibodies after organ transplantation might provide an incisive way to monitor allo-specific immunity and predict graft outcome. Still, the availability of new assays for these antibodies prompts us to pose some questions about results that might be observed. These questions include whether the antibodies detected in the blood are a sensitive measure of alloimmunity, whether the detected antibodies are truly specific for the donor and whether they are noxious for the graft. Here we explain why answers to these questions might interest the basic scientist and clinician.

Platt, Jeffrey L.; Cascalho, Marilia

2010-01-01

152

Understanding donors' motivations: A study of unrelated bone marrow donors  

Microsoft Academic Search

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

1997-01-01

153

75 FR 58400 - Donor Management Research: Improvements in Clinical Management of Deceased Organ Donors  

Federal Register 2010, 2011, 2012, 2013

...focuses on improvements in clinical management of deceased organ donors. Given the continued imbalance between the demand for and supply of deceased donor organs, it is essential that deceased donors be managed appropriately to optimize the...

2010-09-24

154

His-tag protein monitoring by a fast mix-and-measure immunoassay.  

PubMed

Here, we present a fast mix-and-measure immunoassay for the specific semiquantitative detection of His-tagged proteins, for example in E. coli cell lysate. The assay is based on Förster resonance energy transfer (FRET) between a lanthanide dye-labeled low-affinity His-peptide and an acceptor-labeled anti-His-tag antibody. The targeted His-tag protein in the sample displaces the donor-labeled peptide and leads to a concentration-dependent time-resolved fluorescence signal. The assay has a total assay time of less than two minutes including sample preparation. The assay recognizes both, N- and C-terminally tagged proteins. The detection limit is comparable to those obtained in SDS-PAGE or Western Blot, which are used as standard methods for the characterization of His-tag protein expression. Additionally, we demonstrate a full compatibility of the developed assay to cell lysate, and a correlation to detectable bands in a western blot application. In conclusion, this fast, sensitive, specific and affordable mix-and-measure assay provides a timesaving and user-friendly way to quantify recombinant protein expression. It substantially reduces the workload for recombinant protein detection, especially when His-tag-protein-containing fractions in manual chromatographic purifications have to be identified. PMID:25000910

Kreisig, Thomas; Prasse, Agneta A; Zscharnack, Kristin; Volke, Daniela; Zuchner, Thole

2014-01-01

155

Determination of serum tetranectin: technical and clinical evaluation of three sandwich immunoassays.  

PubMed

The performance of two sandwich-type immunoassays for the determination of the tumour marker tetranectin using monoclonal antibodies Hyb 130-13 and 130-14 as catching layer was compared with the performance of a polyclonal assay. Sensitivities were 0.4-0.6 microg/l, and intra- and inter-assay coefficients of variation were < 10% in all assays. One-hundred-and-ten blood donors were examined, and women had higher concentrations of tetranectin in serum than men when measured with monoclonal assays (P < 0.05). In preoperative serum samples from 43 patients with ovarian cancer, tetranectin concentrations were reduced (P < 0.001), and the mean tetranectin concentration decreased with increasing FIGO stage of the patients (P < 0.05). In sera from patients with ovarian cancer, tetranectin concentrations were lower in the polyclonal assay than in the monoclonal assays. This could, hypothetically, be explained by ligand-binding or other conformational changes in tetranectin, influencing the antigenicity of the molecule. PMID:9760017

Thougaard, A V; Høgdall, C K; Kjaer, S K; Blaakaer, J; Jaliashvili, I; Christiansen, M

1998-08-10

156

His-tag protein monitoring by a fast mix-and-measure immunoassay  

PubMed Central

Here, we present a fast mix-and-measure immunoassay for the specific semiquantitative detection of His-tagged proteins, for example in E. coli cell lysate. The assay is based on Förster resonance energy transfer (FRET) between a lanthanide dye-labeled low-affinity His-peptide and an acceptor-labeled anti-His-tag antibody. The targeted His-tag protein in the sample displaces the donor-labeled peptide and leads to a concentration-dependent time-resolved fluorescence signal. The assay has a total assay time of less than two minutes including sample preparation. The assay recognizes both, N- and C-terminally tagged proteins. The detection limit is comparable to those obtained in SDS-PAGE or Western Blot, which are used as standard methods for the characterization of His-tag protein expression. Additionally, we demonstrate a full compatibility of the developed assay to cell lysate, and a correlation to detectable bands in a western blot application. In conclusion, this fast, sensitive, specific and affordable mix-and-measure assay provides a timesaving and user-friendly way to quantify recombinant protein expression. It substantially reduces the workload for recombinant protein detection, especially when His-tag-protein-containing fractions in manual chromatographic purifications have to be identified.

Kreisig, Thomas; Prasse, Agneta A.; Zscharnack, Kristin; Volke, Daniela; Zuchner, Thole

2014-01-01

157

Donor factors that affect the number of organs transplanted per donor  

Microsoft Academic Search

Background—Demographic factors and factors from donors' medical and social history influence the number of organs transplanted per donor. The goal for organ procurement organizations is 4.30 organs transplanted per standard criteria donor. Objective—To examine the influence of factors related to donors' demographics and donors' medical and social histories on the number of organs transplanted per donor. Methods—The medical and social

Leslie Olson; Lynn Cravero

158

Donor Hemovigilance during Preparatory Plasmapheresis  

PubMed Central

Summary Background Reports on unexpected donor events (UEs) during preparatory plasmapheresis (PPP) are scarce, and rarely consider technical UEs. Methods Defined local and systemic UEs were graded by severity; technical UEs were not graded. On January 1, 2008, E.B.P.S.-Logistics (EBPS) installed the UE module for plasma management software (PMS). Donor room physicians entered UEs daily into the PMS. Medical directors reviewed entries quarterly. EBPS compiled data on donors, donations and UEs from January 1, 2008 to June 30, 2011. Results 66,822 UEs were observed during 1,107,846 PPPs for a corrected incidence of 6.55% (1.4% local, 0.55% systemic, 4.6% technical UEs). 3.36% of PPPs were accompanied by 1 UE and 1.18% by >1 UE (2-5). 13.7% of donors undergoing PPP for the first time, 9.7% of those having a second PPP and 4.0% of those having a third or more PPPs were associated with UEs. Most common UEs were repeated venipuncture, and broken-off collection due to venous access problems and small hematomas. Severe systemic UEs occurred at a rate of 36 per 100,000 PPPs. Conclusions Technical UEs were common with PPP. UEs accompanied first and second donations significantly more frequently than for subsequent donations.

Diekamp, Ulrich; Gneissl, Johannes; Rabe, Angela; Kiessig, Stephan T.

2014-01-01

159

Single-Donor Leukophoretic Technique  

NASA Technical Reports Server (NTRS)

Leukocyte separation-and-retrieval device utilizes granulocyte and monocyte property of leukoadhesion to glass surfaces as basis of their separation from whole blood. Device is used with single donor technique and has application in biological and chemical processing, veterinary research and clinical care.

Eberhardt, R. N.

1977-01-01

160

Physician Migration: Donor Country Impact  

ERIC Educational Resources Information Center

Physician migration from the developing to developed region of a country or the world occurs for reasons of financial, social, and job satisfaction. It is an old phenomenon that produces many disadvantages for the donor region or nation. The difficulties include inequities with the provision of health services, financial loss, loss of educated…

Aluwihare, A. P. R.

2005-01-01

161

Semen donors and STD screening.  

PubMed Central

AIM: The British Andrology Society recommends screening semen donors for sexually transmitted infections to minimise the risk of pathogen transmission to the mother and fetus. The aim was to review recent findings of semen donor screening and, if appropriate, recommend changes to the screening protocol. SUBJECTS: 175 consecutive men attending for STD screening between January 1992 and December 1995 who had been preselected by the Department of Obstetrics and Gynaecology as suitable semen donors. METHODS: Retrospective review of case notes and group comparison of demographic and sexual history data. RESULTS: 11 men (6%) had evidence of infection, excluding CMV seropositivity, at their first STD screen. After semen donation, 109 men (63%) were rescreened and, of these, 12% had positive findings. Positive findings at initial screening were predicted by a history of more than one partner in the preceding 6 months (OR 7.11, 95% CI 1.66-30.4) but it did not predict rescreening findings. Other factors such as age, marital status, employment status or past STDs were not predictive for either screen. DISCUSSION: Less than 20% of initial volunteers meet the full criteria of high quality post-thaw semen, no transmissible genetic disorders, and no transmissible pathogens. Sexual history may predict but would not alone preclude all positive STD screening findings. It is essential that sequential STD screening of donors continues and that genitourinary physicians should be involved in this process. Validation of newer diagnostic techniques as screening tests in this setting is required.

Craig, J M; Barratt, C L; Kinghorn, G R

1997-01-01

162

Screening of post-mortem tissue donors for Coxiella burnetii infection after large outbreaks of Q fever in The Netherlands  

PubMed Central

Background After the largest outbreaks of Q fever ever recorded in history occurred in the Netherlands, concern arose that Coxiella may be transmitted via donated tissues of latent or chronically infected donors. The Dutch Health Council recently advised to screen tissue donors, donating high risk tissues, for Coxiella infection. Methods After validation of an enzyme immunoassay (EIA) test for IgG antibodies against phase 2 of C. burnetii for use on post-mortem samples, serum samples of 1033 consecutive Dutch post-mortem tissue donors were tested for IgG antibodies against phase 2 of C. burnetii. Confirmation of reactive results was done by immunofluorescence assay (IFA). All available tissues (corneas, heart valves, skin and bone marrow) from donors with IgG reactivity were tested for presence of Coxiella DNA by PCR. Risk factors for IgG reactivity were investigated. Results After validation of the tests for use on post-mortem samples, 50/1033 donors (4.8%) screened positive for phase 2 anti-Coxiella IgG by EIA, and 31 were confirmed by IFA (3.0%). One donor showed a serological profile compatible with chronic infection. All tested tissues (25 corneas, 6 heart valves, 4 skin and 3 bone marrow) from donors with IgG reactivity tested negative for the presence of Coxiella DNA. Except for living in a postal code area with a high number of Q fever notifications, no risk factors for IgG reactivity were found. Conclusions The strong correlation between notifications and seroprevalence confirms that the used assays are sufficiently specific for use on post-mortem samples, although one has to be aware of differences between batches. Thus, this study provides a validated method for screening tissue donors for infection with Coxiella burnetii that can be used in future outbreaks.

2014-01-01

163

Donor Satisfaction with a New German Blood Donor Questionnaire and Intention of the Donor to Return for Further Donations  

PubMed Central

Summary Background The aim of this study was to describe donor satisfaction regarding different aspects of the new German blood donor questionnaire (BDQ) and to assess whether donor satisfaction is associated with the intention to return for further donations. Methods A random number of 6,600 blood donors, donating at the German Red Cross Blood Service Baden-Wuerttemberg – Hessen, were asked to rate their satisfaction with four different aspects of the BDQ. Chi-square statistics was used to test for associations between satisfaction and the intention to return. Results Most of the donors were satisfied with format and layout (72.7%) and the clarity of the questions (72.5%). However, only 39.5% of the donors were satisfied with the scope of the BDQ and 44.3% with the questions about sexual risk behavior. The lowest satisfaction seemed to be among experienced donors and among donors from small municipalities. Among experienced and very experienced donors, a significant association between the satisfaction with the different aspects and the intention to return became apparent. Conclusion When considering the implementation of the BDQ, Blood Donor Services have to weigh up the advantages of increased deferral rates among donors with high-risk behavior against the potential drop-out of dissatisfied blood donors.

Weidmann, Christian; Muller-Steinhardt, Michael; Schneider, Sven; Weck, Eberhard; Kluter, Harald

2013-01-01

164

Biological Dressings for Skin Graft Donor Sites.  

National Technical Information Service (NTIS)

Three methods of donor site management were tested in 17 patients to determine if any resulted in faster wound healing. Gross inspection and biopsies revealed no differences between donor sites left uncovered or those treated with fine mesh gauze. However...

B. A. Pruitt D. W. Wilmore P. Silverstein R. E. Salisbury

1972-01-01

165

Measurement of donor-specific HLA antibodies following plasma exchange therapy predicts clinical outcome in pediatric heart and lung transplant recipients with antibody-mediated rejection.  

PubMed

Therapeutic plasma exchange (TPE) is an increasingly utilized immunosuppressive adjunct for treatment of antibody-mediated rejection (AMR) following organ transplantation. TPE works through removal of donor-specific HLA antibodies (DSAs) in the recipient's plasma. However, there is no clear laboratory measure evaluating efficacy of removal of DSAs or predicting clinical outcome. We hypothesized that semi-quantitative DSA measurement by multiplex HLA antibody immunoassay may provide qualitative and quantitative data for DSA clearance and predict treatment efficacy. To evaluate this, we retrospectively investigated DSA concentrations and clinical outcome for 21 pediatric patients who received 31 cycles of TPE peri-operatively as an adjunct treatment for transplantation in the setting of a positive cytotoxic crossmatch (CXM) and in recipients with AMR following heart or lung transplantation. Immunoassay measurement of DSAs during 15/20 cycles correlated significantly with clinical outcome in the AMR treatment group (P = 0.02), demonstrating the utility of DSA measurement in predicting clinical outcome. In contrast, immunoassay correlated with clinical outcome in only 7/11 patients treated peri-operatively with TPE for CXM-positive transplantations (P = 0.58). Changes in mean fluorescence intensity (MFI) for the DSAs correlated better with clinical response than surrogate CXM titers in a subset of patients. We conclude that semi-quantitative measurement of DSAs by immunoassay can predict clinical response to TPE for treatment of AMR is more reliable than surrogate CXM titer, and should be used to guide TPE treatment of AMR. PMID:23426730

Jackups, Ronald; Canter, Charles; Sweet, Stuart C; Mohanakumar, T; Morris, Gerald P

2013-08-01

166

Serological Confirmation of Chagas' Disease by a Recombinant and Peptide Antigen Line Immunoassay: INNO-LIA Chagas  

PubMed Central

Although screening for Trypanosoma cruzi antibodies is mandatory in most South American countries, current tests are insensitive and have poor specificity. A recently optimized line immunoassay (the INNO-LIA Chagas assay) for the serological confirmation of Chagas' disease was evaluated at a large blood bank in São Paulo, Brazil. Sera from blood donors who reacted in at least one of three serological screening assays (n = 1,604) and who returned for a follow-up were retested, and the donors were interviewed to assess their epidemiological risk. The results obtained by the confirmatory assay evaluated in this study were compared to those obtained by the three different screening assays. Upon consideration of the consensus results obtained by the three different screening assays as a “gold standard,” the INNO-LIA Chagas assay showed a sensitivity of 99.4% (95% confidence interval [CI], 98.3 to 99.9) and a specificity of 98.1% (95% CI, 96.6 to 99.0) for positive (n = 503) and negative (n = 577) sera. The INNO-LIA Chagas assay confirmed the results for significantly larger numbers of positive samples of at-risk individuals independent of the number of positive screening tests (P = 0.017, Mantel-Haenszel test). In conclusion, the INNO-LIA Chagas assay reliably confirmed the presence of antibodies to T. cruzi and can be implemented as a confirmatory assay for Chagas' disease serology.

Saez-Alquezar, Amadeo; Sabino, Ester C.; Salles, Nanci; Chamone, Dalton F.; Hulstaert, Frank; Pottel, Hans; Stoops, Erik; Zrein, Maan

2000-01-01

167

Screening Donors for Rare Antigen Constellations  

PubMed Central

Summary Screening blood donors for rare antigen constellations has been implemented using simple PCR methods: PCR with enzyme digestion has been used to type donor cohorts for Dombrock antigens, and PCR with sequence-specific priming to identify donors negative for antigens of high frequency. The advantages and disadvantages of the methods as well as their current state is discussed.

Wagner, Franz F.

2009-01-01

168

Living Kidney Donation: The Outcomes for Donors  

PubMed Central

During the past decade, the number of transplantation from living kidney donors has substantially increased worldwide. The rate of increase varies from one country to another. The risk of unilateral nephrectomy to the donor includes perioperative mortality and morbidity plus the long-term risk of living with a single kidney. The rate of perioperative mortality and morbidity is about 0.03% and 10%, respectively. More attention is required to prevent serious complications of laparoscopic donor nephrectomy. A grading system in recording perioperative complications is necessary for making it available to each potential donor. The number of studies on long-term outcome of living donors is very limited. The overall evidence suggests that the risk of end-stage kidney disease is not increased in donors, however, mild renal failure, hypertension and proteinuria are not uncommon in living donors. There is also concern that the incidence of cardiovascular disease may be higher in kidney donors. Establishing living donor registry and follow-up is extremely important. Only through these registries the long-term risk of kidney donation will become more apparent. Because of severe shortage of transplantable kidneys, some transplant centers are now using donors with comorbidities and few centers are involved in transplant tourism with inadequate donor screening and follow-up. Prevention of these unacceptable practices in living kidney donors was emphasized in Amsterdam Forum in 2004 and Istanbul Summit in 2008.

Ghods, A. J.

2010-01-01

169

Sample size consideration for immunoassay screening cut-point determination.  

PubMed

Past decades have seen a rapid growth of biopharmaceutical products on the market. The administration of such large molecules can generate antidrug antibodies that can induce unwanted immune reactions in the recipients. Assessment of immunogenicity is required by regulatory agencies in clinical and nonclinical development, and this demands a well-validated assay. One of the important performance characteristics during assay validation is the cut point, which serves as a threshold between positive and negative samples. To precisely determine the cut point, a sufficiently large data set is often needed. However, there is no guideline other than some rule-of-thumb recommendations for sample size requirement in immunoassays. In this article, we propose a systematic approach to sample size determination for immunoassays and provide tables that facilitate its applications by scientists. PMID:24697778

Zhang, Jianchun; Zhang, Lanju; Yang, Harry

2014-01-01

170

Reusable, polyethylene glycol-structured microfluidic channel for particle immunoassays  

PubMed Central

A microfluidic channel made entirely out of polyethylene glycol (PEG), not PEG coating to silicon or polydimethylsiloxane (PDMS) surface, was fabricated and tested for its reusability in particle immunoassays and passive protein fouling, at relatively high target concentrations (1 mg ml-1). The PEG devices were reusable up to ten times while the oxygen-plasma-treated polydimethyl siloxane (PDMS) device could be reused up to four times and plain PDMS were not reusable. Liquid was delivered spontaneously via capillary action and complicated bonding procedure was not necessary. The contact angle analysis revealed that the water contact angle on microchannel surface should be lower than ~60°, which are comparable to those on dried protein films, to be reusable for particle immunoassays and passive protein fouling.

Han, Jin-Hee; Yoon, Jeong-Yeol

2009-01-01

171

A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics  

NASA Astrophysics Data System (ADS)

A novel, centrifugal disk-based micro-total analysis system (?TAS) for low cost and high throughput semi-automated immunoassay processing was developed. A key innovation in the disposable immunoassay disk design is in a fluidic structure that enables very efficient micro-mixing based on a reciprocating mechanism in which centrifugal acceleration acting upon a liquid element first generates and stores pneumatic energy that is then released by a reduction of the centrifugal acceleration, resulting in a reversal of direction of flow of the liquid. Through an alternating sequence of high and low centrifugal acceleration, the system reciprocates the flow of liquid within the disk to maximize incubation/hybridization efficiency between antibodies and antigen macromolecules during the incubation/hybridization stage of the assay. The described reciprocating mechanism results in a reduction in processing time and reagent consumption by one order of magnitude.

Noroozi, Zahra; Kido, Horacio; Peytavi, Régis; Nakajima-Sasaki, Rie; Jasinskas, Algimantas; Micic, Miodrag; Felgner, Philip L.; Madou, Marc J.

2011-06-01

172

Microbial contamination of donor eyes.  

PubMed

A total number of 1,516 donor eyes received from various sources during the years 1973-1985 were subjected to the isolation of bacterial contamination. The bacterial cultures taken from the pretreatment eyeball showed culture growth in 366 (24.1%) eyes. Of the 366 positive cultures, 331 (21.8%) were bacterial and 35 (2.3%) were fungal. Amongst the bacterial the major contamination was by staphylococcus aureus and albus and pseudomonas aeruginosa. Gentamicin was found to be the most sensitive antibiotic against a wider group of organisms, the next being chloramphenicol. Thus, treatment of a cadaver eye with a solution of normal saline containing 0.1-0.5 mg/ml of gentamicin is recommended before and after the donor eye is enucleated. PMID:3068389

Panda, A; Angra, S K; Venkateshwarlu, K; Mahajan, V M; Mohan, M

1988-01-01

173

Development of an indirect competitive immunoassay for parathion in vegetables  

Microsoft Academic Search

An indirect competitive immunoassay for the insecticide parathion has been optimized and characterized. This assay is based on a monoclonal antibody (2H9) produced from an immunogen, a bovine thyroglobulin (BTG) conjugate wherein the reduced form of parathion was multiply bound to the carrier protein via diazo bonds. Assay was performed in the parathion-HSA coated (0.25?g\\/ml) ELISA format in which antibody

Kun Zeng; Tangbin Yang; Pin Zhong; Shiyi Zhou; Lina Qu; Jia He; Zhisheng Jiang

2007-01-01

174

Cooperative Immunoassays: Ultrasensitive Assays with Mixed Monoclonal Antibodies  

NASA Astrophysics Data System (ADS)

Mixtures of certain monoclonal antibodies appear to bind human chorionic gonadotropin in a ``cooperative'' fashion because they form circular complexes with the hormone. Experiments illustrate how this property might be exploited to develop very sensitive immunoassays for human chorionic gonadotropin or any other antigen. Since the assays are not based on competitive inhibition between radiolabeled and unlabeled antigen, they are much more sensitive than a traditional radioimmunoassay in which either one of the same antibodies is used alone.

Ehrlich, Paul H.; Moyle, William R.

1983-07-01

175

Invalidation of a commercially available human 5?-dihydrotestosterone immunoassay.  

PubMed

Enzyme immunoassays (EIA) are commonly utilized for the evaluation of androgens in biological fluids; however, careful consideration must be given to cross-reactivity with other endogenous sex-steroid hormones. Our purpose was to determine the validity of a commonly-utilized commercially-available dihydrotestosterone (DHT) EIA. Serum samples obtained from older hypogonadal men who participated in a 12-month randomized controlled trial evaluating the effects of testosterone-enanthate (125 mg/week) or vehicle in combination with finasteride (5mg/day) or placebo were assayed for DHT via EIA and using a validated gold-standard LC-MS/MS approach. Additionally, commercially-available (DHT-free) buffer containing graded testosterone doses was evaluated by DHT immunoassay. DHT concentrations measured via EIA were 79% to >1000% higher than values obtained by LC-MS/MS (p<0.05), with the largest differences (415-1128%) occuring in groups receiving finasteride. Both LC-MS/MS and EIA indicated that testosterone-enanthate increased serum DHT to a similar magnitude. In contrast, finasteride-induced reductions in DHT were detected by LC-MS/MS, but not EIA (p<0.05). No significant associations were present for DHT concentrations between measurement techniques. Cross-reactivity of testosterone with the immunoassay ranged from 18% to 99% and DHT concentrations measured by EIA were highly associated with the spiked testosterone concentrations in DHT-free buffer (r=0.885, p<0.001). In conclusion, we provide evidence invalidating a commonly-utilized commercially-available DHT immunoassay because significant cross-reactivity exists between testosterone and the EIA and because the changes in DHT observed via EIA were not associated with a validated gold-standard measurement technique. The cross-reactivity of testosterone is particularly concerning because testsoterone is present in 100-fold greater concentrations than is DHT within the circulation. PMID:24012740

Yarrow, Joshua F; Beck, Darren T; Conover, Christine F; Beggs, Luke A; Goldberger, Bruce A; Borst, Stephen E

2013-12-11

176

Conformation-sensitive immunoassay: optimisation, validation and evaluation.  

PubMed

A conformation-sensitive immunoassay (CSI) has recently been developed (Pfund and Bourdage, 1990). This paper describes the optimal laboratory protocol which makes this method useful as an early screening procedure for conformation-sensitive monoclonal antibodies. The method was validated with a panel of 12 monoclonal antibodies. Results from our experiments confirm that this variant of CSI can be applied in the analysis of purified proteins and glycoproteins, as well as complex mixtures of antigens. PMID:7678631

Lolov, S; Tyutyulkova, S; Marinova, I; Kehayov, I; Kyurchiev, S

1993-01-01

177

Development of One-Step Fluorescence Polarization Immunoassay for Progesterone  

Microsoft Academic Search

A one-step fluorescence polarization immunoassay (FPIA) was developed to measure progesterone level using an immunocomplex single reagent (SR), a preequilibrated mixture of antibody and tracer. Several fluores- cence-labeled progesterone tracers were synthesized using the combination of two progesterone derivatives, 11a a- hemisuccinyloxyprogesterone (P-11HS) and progesterone-3-(O-carboxymethyl)oxime (P-3CMO), and three fluo- rescence labels, fluoresceinamine isomer I and II, and ethylenediamine fluoresceinthiocarbamyl (EDF).

Ji Youn Hong; Myung Ja Choi

2002-01-01

178

Preparation of Horseradish Peroxidase Hydrazide and Its Use in Immunoassay  

Microsoft Academic Search

Preparation of horseradish peroxidase (HRP) hydrazide that is HRP linked to adipic acid dihydrazide (HRP-ADH) and its use in enzyme immunoassay (EIA) is described. In this new strategy, horseradish peroxidase was conjugated to adipic acid dihydrazide using a carbodiimide coupling method. The resulting HRP-ADH was then coupled to cortisol-21-hemisuccinate (Cortisol-21-HS) to prepare enzyme conjugate. The prepared cortisol-21-HS coupled ADH-HRP (Cortisol-21-HS-ADH-HRP)

Tulsidas G. Shrivastav

2003-01-01

179

EVALUATION OF A NEW IMMUNOASSAY FOR URINARY ETHYL GLUCURONIDE TESTING  

Microsoft Academic Search

Aims: The minor ethanol metabolite ethyl glucuronide (EtG) is used as a sensitive and specific test for recent alcohol consumption with clinical and forensic applications. This study evaluated a new enzyme immunoassay (DRI-EtG EIA, Microgenics Corp.) for determination of the EtG concentration in urine samples. Methods: Evaluation was done using the kit calibrators (range 0-5.0 mg\\/L) and controls, an external

OLOF BECK; ANDERS HELANDER

2007-01-01

180

Optical Scanner for Immunoassays With Up-Converting Phosphorescent Labels  

Microsoft Academic Search

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

2008-01-01

181

An indirect enzyme immunoassay for the mycotoxin citrinin.  

PubMed Central

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%.

Abramson, D; Usleber, E; Martlbauer, E

1995-01-01

182

Laparoscopic live-donor nephrectomy.  

PubMed

Laparoscopic nephrectomy with ablative intent has been performed clinically. The current study aimed to determine whether a physiologically and anatomically intact kidney suitable for transplantation could be harvested laparoscopically. Three weeks after an ablative laparoscopic right nephrectomy, 15 pigs were divided into two groups: the study group (n = 10) underwent a laparoscopic live-donor left nephrectomy of the solitary kidney and conventional autotransplantation; the control group (n = 5) underwent an open live-donor left nephrectomy of the solitary kidney and conventional autotransplantation. All study kidneys underwent laparoscopic in situ hypothermic perfusion. The mean length of the left renal artery and vein were similar in the study and control groups: 3.1 cm and 3.4 cm, respectively, in the study group compared with 2.5 cm and 3.8 cm, respectively, in the control group (P = 0.5). No intraoperative renal vascular injuries or postoperative ureteral complications were noted in either group. Renal histopathologic examination immediately after live-donor nephrectomy and at 1 month post-transplant showed similar findings in the two groups. The mean serum creatinine at 7 and 30 days postoperatively was not significantly different: 2.1 mg/dL and 1.6 mg/dL, respectively, in the study group and 1.7 mg/dL, and 1.4 mg/dL, respectively, in the control group (P = 0.4). We conclude that laparoscopic live-donor nephrectomy can be performed safely and reproducibly in the porcine model. PMID:8061673

Gill, I S; Carbone, J M; Clayman, R V; Fadden, P A; Stone, M A; Lucas, B A; McRoberts, J W

1994-04-01

183

An immunoassay using an electro-microchip, nanogold probe and silver enhancement  

Microsoft Academic Search

This paper presents a novel immunoassay using an electro-microchip to detect the immuno-reaction signal, gold nanoparticles\\u000a (ANPs) as a label of antigen or antibody and as a catalyst for silver precipitation, and the silver enhancement reaction to\\u000a magnify the detection signal. This study is based on the direct immunoassay (two-layer format) and the sandwich immunoassay\\u000a (three-layer format). The ANPs are

Kuei-Ling Su; Hao-Hsuan Huang; Tsung Chain Chang; Hong-Ping Lin; Yu-Cheng Lin; Wei-Ting Chen

2009-01-01

184

Using an electro-microchip, a nanogold probe, and silver enhancement in an immunoassay  

Microsoft Academic Search

This paper presents a novel immunoassay that uses an electro-microchip to detect the immuno-reaction signal, gold nanoparticles (ANPs) as a label of antigen or antibody and as a catalyst for silver precipitation, and the silver enhancement reaction to magnify the detection signal. This study is based on the direct immunoassay (two-layer format) and the sandwich immunoassay (three-layer format). The ANPs

Chia-Hsien Yeh; Hao-Hsuan Huang; Tsung-Chain Chang; Hong-Ping Lin; Yu-Cheng Lin

2009-01-01

185

Copalis technology: immunoassay diagnostics using latex microparticles and colloidal gold  

NASA Astrophysics Data System (ADS)

CopalisTM,1 (coupled particle light scattering) is an innovative particle-based homogeneous immunoassay technology that allows rapid, sensitive, simultaneous determination of multiple analytes in a single fluid sample. Particles, their aggregates and cells are differentiated on the basis of light scatter measurements as they flow across a finely focused elliptical beam produced by a semiconductor laser. Two distinct complementary test formats have been developed, one based on particle self-agglutination and the other based on binding of colloidal gold particles to latex micro-spheres. In the first format, particle self- agglutination gives rise to dimers and oligomers which are classified and enumerated from the light scatter histogram. The extent of agglutination determines the test result. The second format uses micron-sized latex micro-spheres as the carriers onto which varying amounts of colloidal gold particles are bound in sandwich or competitive immunoassay formats. The main characteristic of this type of immunoassay is the relative broadening of light scatter histogram peaks for particles coated with colloidal gold. The extent of broadening is used to determine the concentration of the analyte. With both formats, the use of latex particles of different sizes in the same reaction mixture allows multiple simultaneous assays. This technology yields an analytical sensitivity of 10-13 M, an improvement by several orders of magnitude over other homogeneous assay technologies.

Kochar, Manish S.; Benecky, Michael J.; Sridhar, G.

1996-04-01

186

Graphene-based immunoassay for human lipocalin-2.  

PubMed

We have developed a highly sensitive immunoassay using graphene nano platelets (GNPs) for the rapid detection of human lipocalin-2 (LCN2) in plasma, serum, and whole blood. It has the dynamic range, linear range, limit of detection, and analytical sensitivity of 0.6 to 5120, 80 to 2560, 0.7, and 1pg/ml, respectively. It is the most sensitive assay for the detection of LCN2, which has 80-fold higher analytical sensitivity and 3-fold lesser immunoassay duration than the commercially available sandwich enzyme-linked immunosorbent assay (ELISA) kit. The functionalization of microtiter plate (MTP) with GNPs, dispersed in 3-aminopropyltriethoxysilane (APTES), provided the increased surface area that leads to higher immobilization density of capture antibodies. Moreover, the generation of free amino groups on MTP and GNPs by APTES enables the leach-proof covalent crosslinking of anti-human LCN2 capture antibody by its carboxyl groups using 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) as the heterobifunctional crosslinker. The anti-LCN2 antibody-bound MTPs were highly stable given that they did not show any significant decrease in their functional activity when stored at 4°C in 0.1M phosphate-buffered saline (PBS) for 8weeks. The developed immunoassay correlated well with the conventional ELISA, thereby demonstrating its high precision and potential utility for highly sensitive analyte detection in industrial and clinical settings. PMID:24161611

Vashist, Sandeep Kumar

2014-02-01

187

Multiplexed electrochemical immunoassay of biomarkers using chitosan nanocomposites.  

PubMed

In this work, a novel and sensitive multiplexed immunoassay protocol for simultaneous electrochemical determination of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) was designed using functionalized chitosan composites. The immunosensing platform was prepared via immobilizing capture anti-AFP and anti-CEA on chitosan-Au nanoparticles (AuNPs) through EDC/NHS linking. The signal tags were fabricated by immobilizing electroactive redox probes - Prussian blue (PB) and ferrocenecarboxylic acid (Fc) on chitosan (CHIT), following by absorbing AuNPs to immobilize labeled anti-AFP and anti-CEA, respectively. A sandwich-type immunoassay format was employed for the simultaneous detection of AFP and CEA. The assay was based on the electrochemical oxidation/reduction of the redox species in signal tags, which has a relationship with the concentration of analytes. Experimental results revealed that the multiplexed electrochemical immunoassay enabled the simultaneous monitoring of AFP and CEA with a wide range of 0.05-100 ng mL(-1) for both AFP and CEA. The detection limits (LOD) was 0.03 ng mL(-1) for AFP and 0.02 ng mL(-1) for CEA (S/N=3). The assay results of serum samples with the proposed method were in a good agreement with the reference values from standard ELISA method. And the negligible cross-reactivity between the two analytes makes it possesses potential promise in clinical diagnosis. PMID:24413402

Chen, Xia; Ma, Zhanfang

2014-05-15

188

Multiplex Electrochemical Immunoassay Using Gold Nanoparticle Probes and Immunochromatographic Strips  

SciTech Connect

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.

Mao, Xun; Baloda, Meenu; Gurung, Anant; Lin, Yuehe; Liu, Guodong

2008-10-20

189

History of inductively coupled plasma mass spectrometry-based immunoassays  

NASA Astrophysics Data System (ADS)

The analysis of biomolecules requires highly sensitive and selective detection methods capable of tolerating a complex, biological matrix. First applications of biomolecule detection by ICP-MS relied on the use of heteroelements as a label for quantification. However, the combination of immunoassays and ICP-MS facilitates multiparametric analyses through elemental tagging, and provides a powerful alternative to common bioanalytical methods. This approach extends the detection of biomarkers in clinical diagnosis, and has the potential to provide a deeper understanding of the investigated biological system. The results might lead to the detection of diseases at an early stage, or guide treatment plans. Immunoassays are well accepted and established for diagnostic purposes, albeit ICP-MS is scarcely applied for the detection of immune-based assays. However, the screening of biomarkers demands high throughput and multiplex/multiparametric techniques, considering the variety of analytes to be queried. Finally, quantitative information on the expression level of biomarkers is highly desirable to identify abnormalities in a given organism. Thus, it is the aim of this review to introduce the fundamentals, and to discuss the enormous strength of ICP-MS for the detection of different immunoassays on the basis of selected applications, with a special focus on LA-ICP-MS.

Giesen, Charlotte; Waentig, Larissa; Panne, Ulrich; Jakubowski, Norbert

2012-10-01

190

Heterogeneous Immunoassays Using Magnetic beads On a Digital Microfluidic Platform  

PubMed Central

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.

2009-01-01

191

Supramolecular hierarchy among halogen-bond donors.  

PubMed

Through a combination of structural chemistry, vibrational spectroscopy, and theory, we have systematically examined the relative structure-directing importance of a series of ditopic halogen-bond (XB) donors. The molecular electrostatic potential surfaces of six XB donors were evaluated, which allowed for a charge-based ranking. Each molecule was then co-crystallized with 21 XB acceptors and the results have made it possible to map out the supramolecular landscape describing the competition between I/Br-ethynyl donors, perfluorinated I/Br donors, and I/Br-phenyl based donors. The results offer practical guidelines for synthetic crystal engineering driven by robust and directional halogen bonds. PMID:24130038

Aakeröy, Christer B; Baldrighi, Michele; Desper, John; Metrangolo, Pierangelo; Resnati, Giuseppe

2013-11-25

192

Superfund Innovative Technology Evaluation (SITE) report for the Westinghouse Bio-Analytic Systems pentachlorophenol (PCPpcp) immunoassays  

SciTech Connect

The results of the demonstration of two Westinghouse Bio-Analytic Systems (WBAS) immunoassay technologies are described in the report. The immunoassays measure parts per billion concentrations of pentachlorophenol in environmental water samples. The study was conducted under the Superfund innovative Technology Evaluation (SITE) Program and designed to evaluate the ruggedness and utility of a semiquantitative immunoassay field kit. Results obtained from the field kit were compared to those obtained from a quantitative, high-sample-capacity plate immunoassay. The results of the WBAS immunoassay demonstration support the conclusion that the field immunoassay is a useful screening tool. The demonstration verified that the method can provide qualitative or semiquantitative screening information. Although the results were more variable than had been anticipated, the incorporation of additional procedural precautions and carefully chosen quality control acceptance criteria for on-site analysis could improve performance substantially. Both immunoassays produced results biased high compared to the GC/MS results, but the tendency was not large and may have been partly due to loss during sample extraction (EPA Method 3510) prior to analysis by gas chromatography/mass spectrometry. The detection of structurally related compounds by the immunoassays may have also contributed to the high bias. The results indicate that the plate immunoassay is an accurate and precise method for quantitating pentachlorophenol in water.

Silverstein, M.E.; White, R.J.; Gerlach, R.W.; Van Emon, J.M.

1992-05-01

193

An immunoassay utilizing the DNA-coated polydiacetylene micelles as a signal generator.  

PubMed

Immunoassay is an important technique to detect the disease biomarkers and pathogenic biological agents which often present at low levels in clinical samples. To improve sensitivity of the immunoassay, here we described the DNA-coated, nano-sized micelles in which the DNA strands play a role as signal generators in an immunoassay. This micelle-based immunoassay was evaluated for quantitation of a liver cancer biomarker and the sensitivity of the method was compared with those of the conventional methods. PMID:23518279

Hoang, Hoa Thi; Lee, Taemin; Kim, Byeong-Su; Han, Ki-Cheol; Ahn, Dae-Ro

2013-05-01

194

Cadaver versus living donor kidneys: Impact of donor factors on antigen induction before transplantation  

Microsoft Academic Search

Cadaver versus living donor kidneys: Impact of donor factors on antigen induction before transplantation.BackgroundIt is widely recognized that living-related donor (LRD) renal allografts have a higher overall graft survival than cadaver donor transplants. We tested the hypothesis that part of this is attributable to LRD kidneys being obtained under optimal conditions from healthy donors, whereas cadaveric kidneys may have experienced

Dicken D. H. Koo; Kenneth I. Welsh; Andrew J. Mclaren; Justin A. Roake; Peter J. Morris; Susan V. Fuggle

1999-01-01

195

Renal Transplantation from Elderly Living Donors  

PubMed Central

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.

Akoh, Jacob A.; Mathuram Thiyagarajan, Umasankar

2013-01-01

196

The challenge of improving donor heart preservation.  

PubMed

Heart transplantation has in recent years become the treatment of choice for end stage heart failure. However while the waiting list for transplantation is growing steadily, the donor pool is not increasing. Therefore, in order to meet demand, transplant programs are using older, "marginal donors" and accepting longer ischaemic times for their donor hearts. As donor organs are injured as a consequence of brain death, during the period of donor management, at organ harvest, preservation, implantation and reperfusion, expansion of acceptance criteria places a great burden on achieving optimal long-term outcomes. However, at each step in the process of transplantation strategies can be employed to reduce the injury suffered by the donor organs. In this review, we set out what steps can be taken to improve the quality of donor organs. PMID:16352173

McCrystal, Graham D; Pepe, Salvatore; Esmore, Donald S; Rosenfeldt, Franklin L

2004-03-01

197

Tele-recruitment for Donor Retention.  

PubMed

Blood transfusion services are the integral part of health care system and these services have safe blood transfusion as the major goal. Voluntary blood donation is the key to safe blood and this safety is further enhanced when the voluntary blood donors become repeat/regular donors. Retention of donors is therefore a very crucial strategy to ensure enhanced blood safety. Tele-recruitment is an effective medium of recruiting and more importantly retaining donors via means of telephone/Short Message Service. This study was carried out at a standalone blood bank during the period from January to December 2011 with objectives of donor retention, relationship management with the support of personnel with good communication skills, Donor data base, Integrated software and communication facility. For Initial 4 months there was no tele-recruiter, then for 2 months two tele-recruiter and for next 6 months three tele-recruiter were dedicated. Only impact of tele-recruitment on in-house donation was taken into consideration. 2,091 donors were recruited through tele-recruitment in this eight-month period. This was 63 % of in-house donations and 13 % of total donations. In other words out of every five in-house donations, three donations were from people contacted through tele-recruitment. Repeat voluntary blood donation is the safest donation. Tele-recruitment does this by converting 'first-time' donors into repeat/regular donors. Simple intervention like reminder calls on telephone can be highly effective tool to retain donors. Tele-recruitment helped the blood center establish relationships with individual donors, and, maybe, even the society at large. Tele-recruitment is a very low-cost model which can be easily replicated in all kind of blood banks, be it standalone, or a hospital based. Even the blood centers which are largely dependent on replacement donors can possibly have good results and convert replacement donors into repeat/regular voluntary blood donors. PMID:24554816

Agrawal, Amit; Tiwari, A

2014-03-01

198

A new digoxin immunoassay substantially free of interference by digoxin immunoreactive factor.  

PubMed

We have evaluated the new Roche digoxin "On Line" procedure for use in a pediatric population with particular interest in the potential for interference by digoxin-like immunoreactive factor (DLIF). An initial study comparing digoxin values obtained with the new Roche procedure with determinations on an Abbott TDx, American Dade Stratus, and COBAS-FARA using Microgenics Cedia reagents, found good correlations with these established methods. The Roche method was suitably precise and utilized either serum or plasma. Interference by DLIF was assessed by analyzing specimens from patients not receiving digoxin but likely to contain DLIF, with the argument that non-zero values represent cross-reactivity of anti-digoxin antibodies with DLIF endogenous to these specimens. When specimens from neonates, women with second/third trimester pregnancies, and patients with renal and liver failure were assayed with the Roche, Stratus, and TDx methods, all three methods measured DLIF in some specimens, but the Roche method possessed the lowest overall DLIF interference. The modest extent of DLIF interference and the requirement of a small amount of specimen make the Roche method superior in monitoring digoxin in a pediatric population. PMID:7624908

Jiang, F; Wilhite, T R; Smith, C H; Landt, M

1995-04-01

199

Recovery and safety profiles of marrow and PBSC donors: experience of the National Marrow Donor Program.  

PubMed

The National Marrow Donor Program (NMDP) has been facilitating hematopoietic cell transplants since 1987. Volunteer donors listed on the NMDP Registry may be asked to donate either bone marrow (BM) or peripheral blood stem cells (PBSC); however, since 2003, the majority of donors (72% in 2007) have been asked to donate PBSC. From the donor's perspective these stem cell sources carry different recovery and safety profiles. The majority of BM and PBSC donors experienced symptoms during the course of their donation experience. Pain is the number 1 symptom for both groups of donors. BM donors most often reported pain at the collection site (82% back or hip pain) and anesthesia-related pain sites (33% throat pain; 17% post-anesthesia headache), whereas PBSC donors most often reported bone pain (97%) at various sites during filgrastim administration. Fatigue was the second most reported symptom by both BM and PBSC donors (59% and 70%, respectively). PBSC donors reported a median time to recovery of 1 week compared to a median time to recovery of 3 weeks for BM donors. Both BM and PBSC donors experienced transient changes in their WBC, platelet, and hemoglobin counts during the donation process, with most counts returning to baseline values by 1 month post-donation and beyond. Serious adverse events are uncommon, but these events occurred more often in BM donors than PBSC donors (1.34% in BM donors, 0.6% in PBSC donors) and a few BM donors may have long-term complications. NMDP donors are currently participating in a randomized clinical trial that will formally compare the clinical and quality-of-life outcomes of BM and PBSC donors and their graft recipients. PMID:18721778

Miller, John P; Perry, Elizabeth H; Price, Thomas H; Bolan, Charles D; Karanes, Chatchada; Boyd, Theresa M; Chitphakdithai, Pintip; King, Roberta J

2008-09-01

200

Rapid detection of autoantibodies to dsDNA with the particle gel immunoassay (ID-PaGIA)  

PubMed Central

Patients and methods: Serum samples were collected from 40 unselected healthy blood donors and 200 patients with systemic lupus erythematosus (SLE) or a positive antinuclear antibody screen, or both. The samples were tested in the presence of red high density polystyrene particles coated with purified human dsDNA using the gel technique (Micro Typing System, ID-PaGIA, particle gel immunoassay). The results were compared with those obtained by the two standard anti-dsDNA antibody detection methods, Crithidia luciliae immunofluorescence test (CLIF) and enzyme linked immunosorbent assay (ELISA). Results: The three anti-dsDNA assays exhibited an overall agreement of 87% and significant correlation with each other (p<0.0001). In the SLE group (n=71), 45 patients (63%) were found to be positive by ID-PaGIA compared with only 11/129 (9%) patients in the non-SLE group. Thus the ID-PaGIA had a sensitivity of 63%, and a specificity of 92% for SLE. In comparison, the standard detection methods showed sensitivities of 62% (CLIF) and 70% (ELISA) and specificities of 99% (CLIF) and 84% (ELISA) for SLE. Anti-dsDNA reactivity in the agglutination assay correlated closely with the quantities of antibody obtained by CLIF (r=0.81, p<0.0001) and ELISA (r=0.73, p<0.0001). Conclusions: The new particle gel agglutination test is a sensitive and specific immunoassay. It is a simple test procedure that might be well suited as a rapid screening method.

Seltsam, A; Schwind, P; Abraham, K; Hiepe, F; Cygan, S; Aebischer, I; Salama, A

2002-01-01

201

Performance of a Time-Resolved Fluorescence Immunoassay for Measuring Varicella-Zoster Virus Immunoglobulin G Levels in Adults and Comparison with Commercial Enzyme Immunoassays and Merck Glycoprotein Enzyme Immunoassay  

Microsoft Academic Search

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

2006-01-01

202

Living donor practices in the United States.  

PubMed

Living kidney donation is a common procedure in the United States. Substantial variation exists between 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 and future studies. Certain trends in living donation practices have become apparent from surveys of transplant programs over the past few decades. Over the past 25 years, opposition to living unrelated donation in the United States 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 Organ Procurement and Transplantation Network for 2 years after donation, a majority of donors are lost to follow-up by 1 year. The most commonly cited barriers to donor follow-up include donor inconvenience, cost issues including reimbursement to care providers, and direct and indirect costs to donors. In this article, we review the current knowledge about living donor practices in the United States. PMID:22732040

Mandelbrot, Didier A; Pavlakis, Martha

2012-07-01

203

Living Donor Practices in the United States  

PubMed Central

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.

Mandelbrot, Didier A.; Pavlakis, Martha

2012-01-01

204

Molecular blood grouping of donors.  

PubMed

For many decades, hemagglutination has been the sole means to type blood donors. Since the first blood group gene cloning in the early 1990s, knowledge on the molecular basis of most red blood cell, platelet and neutrophil antigens brought the possibility of using nucleotide-based techniques to predict phenotype. This review will summarized methodologies available to genotype blood groups from laboratory developed assays to commercially available platforms, and how proficiency assays become more present. The author will also share her vision of the transfusion medicine future. The field is presently at the crossroads, bringing new perspectives to a century old practice. PMID:24656492

St-Louis, Maryse

2014-04-01

205

Analysis of Chinese Donors' Return Behavior  

PubMed Central

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, 2–3 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.

Guo, Nan; Wang, Jingxing; Ness, Paul; Yao, Fuzhu; Dong, Xiangdong; Bi, Xinhong; Mei, Heili; Li, Julin; He, Weilan; Lu, Yunlai; Ma, Hongli; Wen, Xiuqiong; Huang, Mei; Wright, David J.; King, Melissa; High, Patrick; Nelson, Kenrad; Shan, Hua

2010-01-01

206

Gamete donors' expectations and experiences of contact with their donor offspring  

PubMed Central

STUDY QUESTION What are the expectations and experiences of anonymous gamete donors about contact with their donor offspring? SUMMARY ANSWER Rather than consistently wanting to remain distant from their donor offspring, donors' expectations and experiences of contact with donor offspring ranged from none to a close personal relationship. WHAT IS KNOWN ALREADY Donor conception is part of assisted reproduction in many countries, but little is known about its continuing influence on gamete donors' lives. STUDY DESIGN, SIZE, DURATION A qualitative research model appropriate for understanding participants' views was employed; semi-structured interviews were conducted during January–March 2013. PARTICIPANTS/MATERIALS, SETTING, METHODS Before 1998, gamete donors in Victoria, Australia, were subject to evolving legislation that allowed them to remain anonymous or (from 1988) to consent to the release of identifying information. An opportunity to increase knowledge of donors' expectations and experiences of contact with their donor offspring recently arose in Victoria when a recommendation was made to introduce mandatory identification of donors on request from their donor offspring, with retrospective effect. Pre-1998 donors were invited through an advertising campaign to be interviewed about their views, experiences and expectations; 36 sperm donors and 6 egg donors participated. MAIN RESULTS AND THE ROLE OF CHANCE This research is unusual in achieving participation by donors who would not normally identify themselves to researchers or government inquiries. Qualitative thematic analysis revealed that most donors did not characterize themselves as parents of their donor offspring. Donors' expectations and experiences of contact with donor offspring ranged from none to a close personal relationship. LIMITATIONS, REASONS FOR CAUTION It is not possible to establish whether participants were representative of all pre-1998 donors. WIDER IMPLICATIONS OF THE FINDINGS Anonymous donors' needs and desires are not homogeneous; policy and practice should be sensitive and responsive to a wide range of circumstances and preferences. Decisions made to restrict or facilitate contact or the exchange of information have ramifications for donors as well as for donor-conceived people. STUDY FUNDING/COMPETING INTEREST(S) The study was funded by the Victorian Department of Health. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER Not applicable.

Kirkman, Maggie; Bourne, Kate; Fisher, Jane; Johnson, Louise; Hammarberg, Karin

2014-01-01

207

Preparation of Enzyme Conjugate through Adipic Acid Dihydrazide as Linker and Its Use in Immunoassays  

Microsoft Academic Search

The direct coupling of the carboxylic derivative of steroids to the amino group of enzymes is a well-established method in steroid enzyme immunoassays for making enzyme conjugates (1). Horseradish peroxidase (HRP), containing six lysine residues in the sequence, is a widely used enzyme in enzyme immunoassays; in practice, how- ever, only one or two of these are generally available for

Anupam Basu; Tulsidas G. Shrivastav; Kiran P. Kariya

208

Immunoassay of low to moderately abundant anionic proteins utilizing selective immobilization to chitosan-coated plates  

Microsoft Academic Search

The quantitation of low to moderately abundant serum proteins is a common problem encountered in biochemistry. A physical property of the antigen of interest needs to be exploited in the initial binding step of an immunoassay resulting in capture (purification). We describe a two-stage immunoassay utilizing chromogenic and chemiluminescent substrates which is applied to two serum anionic proteins. In this

Karen J. Rees-Milton; Tassos P. Anastassiades

2010-01-01

209

REVIEW OF PRACTICAL ASPECTS OF MAGNETIZABLE SOLID STATE SEPARATION TECHNIQUES IN IMMUNOASSAYS  

Microsoft Academic Search

The use of ready-made commercial immunoassay kits has been in practice in our country for the last 35 years, which has utilized billions of dollars. Efforts are however, in progress to develop own reagents to replace commercial technology with the local one. A simple immunoassay technique involves a reaction between the analyte i.e., antigen (substance to be measured) and a

K. M. SAJID

210

Foil-based BioMEMS for electrochemical capillary immunoassay for hepatitis serology  

Microsoft Academic Search

A foil-based BioMEMS for electrochemical capillary immunoassay for hepatitis serology is presented. Immobilization of the hepatitis antigen utilizing capillary forces and special stopping barriers in foil based microsystems and the application of it in fast immunoassays will be shown. The measurement starts with the addition of the antibody containing human serum sample. Subsequently the signal antibody labelled with glucose oxidase

Isabella Moser; Barbara Enderle; Cordula Kohn; Gerhard Jobst; Gerald Urban

2005-01-01

211

Micromotor-based lab-on-chip immunoassays  

NASA Astrophysics Data System (ADS)

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.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. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32400h

García, Miguel; Orozco, Jahir; Guix, Maria; Gao, Wei; Sattayasamitsathit, Sirilak; Escarpa, Alberto; Merkoçi, Arben; Wang, Joseph

2013-01-01

212

The ethics of donor human milk banking.  

PubMed

Background: This case study of donor human milk banking and the ethics that govern interested parties is the first time the ethics of donor milk banking has been explored. Methods and Results: Two different models of ethics and their direct impact on donor milk banking are examined: biomedical ethics and public health ethics. How these models and principles affect different aspects of donor human milk banking and the parties involved in the delivery of this service are elucidated. Interactions of parties with each other and how the quality and type of interaction affects the ethical delivery of donor milk banking services are described. Crystallization is at the heart of the qualitative methodology used. Writing as a method of inquiry, an integrative research review, and personal experience are the three methods involved in the crystallization process. Conclusion: Suggestions are made for improving access and knowledge of banked donor human milk, a valuable public health resource. PMID:17661555

Arnold, Lois D W

2006-01-01

213

AN ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) TESTING OF THREE IMMUNOASSAY TEST KITS FOR ANTHRAX, BOTULINUM TOXIN AND RICIN  

EPA Science Inventory

Immunoassay test kits are based on immunoassay methods, where specific antibodies are used to detect and measure the contaminants of interest. Immunoassay test kits rely on the reaction of a contaminant or antigen with a selective antibody to give a product that can be measures....

214

Performance characteristics of three automated immunoassays for thyroid hormones  

PubMed Central

Background: Since the introduction of the first radioimmunoassay, several improvements have been made in the design of immunoassays such as method of antibody production, labeling, automation and detection technology. We performed an analytical evaluation of the new electrochemiluminescent immunoassay (ECLIA) for serum TSH, FT4 and T3 in the Elecsys 2010 immunoassay system and compared the results of this method with those of radioimmunoassay ( RIA) [immunoradiometric (IRMA) for TSH] and Elisa. Methods: Fasting serum from 112 hypo, hyper and euthyroid patients were used to evaluate the minimum detectable concentration, intra- and inter-assay precisions for TSH, FT4, T3, linearity for TSH assay and method comparison study. Results: Within the analytical range tested, intra-assay coefficient of variation was < 2.3% for TSH, 2.3% for FT4 and 7.8% for T3. The inter-assay coefficient of variation was < 2.9% for TSH, 2.5% for FT4 and 12.3% for T3. The measurement of diluted sera indicated a desirable percentage of recovery for TSH. No correlation was found between Elecsys 2010 and Elisa /IRMA for TSH. The comparison of results of the Elecsys ECLIA assay with those of Elisa and RIA for T4 were: T4 (ECLIA) = -0.612+0.999, T4 (Elisa, r= 0.88) and T4 (ECLIA)=0.642+0.942 T4 (RIA, r=0.957), while ECLIA assay with Elisa and RIA for T3 were: T3 (ECLIA)= 0.242+0.908 T3 (Elisa, r=0.8) and T3 (ECLIA) = -0.029+1.01 T3 (RIA, r=0.957). Conclusion: The results show that Elecsys 2010 is an automated reliable, efficient and technically excellent instrument to use in the measurement of serum TSH, T4 and T3.

Kazerouni, Faranak; Amirrasouli, Houshang

2012-01-01

215

NCI at Frederick: Donor Eligibility and Enrollment  

Cancer.gov

Establishment of the RDP donor pool is accomplished by voluntary employee enrollment. Individuals must be employees of the Frederick National Lab or Fort Detrick community, must be age 18 or older, and weigh at least 110 pounds to be eligible for inclusion in the RDP donor pool. In addition, donors must attend a scheduled RDP Counseling meeting and submit to select blood-borne pathogen and CBC testing upon inclusion and every six months thereafter.

216

Neurogenic stress cardiomyopathy in heart donors.  

PubMed

Cardiac transplantation is severely restricted by donor availability. Left ventricular dysfunction due to neurogenic stress cardiomyopathy is often seen during donor evaluation and often presents a clinical dilemma for procurement. We report a case of a 23-year-old man with severe left ventricular dysfunction whose heart was successfully procured for transplantation. The brief case report is followed by an extensive review of neurogenic stress cardiomyopathy as well as donor evaluation for cardiac transplantation in the setting of such cardiomyopathy. PMID:24374112

Mohamedali, Burhan; Bhat, Geetha; Tatooles, Antone; Zelinger, Allan

2014-03-01

217

Development and evaluation of an indirect enzyme immunoassay for detection of porcine antibodies to pseudorabies virus.  

PubMed Central

An indirect enzyme immunoassay is described for detection of porcine serum antibody to pseudorabies virus. The analytical sensitivity of the enzyme immunoassay was found to be approximately 4.5 log 4 X 10 (5120 times) greater than the serum neutralization test, based on parallel end point titrations. The diagnostic sensitivity of the enzyme immunoassay was comparable or superior to that of the serum neutralization, based on the earliest detectable antibody after infection of swine with pseudorabies virus by intranasal or intrauterine routes or by contact with infected pigs. The enzyme immunoassay, at a screening dilution of 1:20, gave 100% agreement with ELISA results provided with a U.S. Department of Agriculture-Animal and Plant Health Inspection Service proficiency panel of 40 sera. One serum having demonstrable antibody by the enzyme immunoassay was seronegative by the serum neutralization test.

Afshar, A; Wright, P F; Dulac, G C

1986-01-01

218

Species Specific Bacterial Spore Detection Using Lateral-Flow Immunoassay with DPA-Triggered Tb Luminescence  

NASA Technical Reports Server (NTRS)

A method of detecting bacterial spores incorporates (1) A method of lateral-flow immunoassay in combination with (2) A method based on the luminescence of Tb3+ ions to which molecules of dipicolinic acid (DPA) released from the spores have become bound. The present combination of lateral-flow immunoassay and DPA-triggered Tb luminescence was developed as a superior alternative to a prior lateral-flow immunoassay method in which detection involves the visual observation and/or measurement of red light scattered from colloidal gold nanoparticles. The advantage of the present combination method is that it affords both (1) High selectivity for spores of the species of bacteria that one seeks to detect (a characteristic of lateral-flow immunoassay in general) and (2) Detection sensitivity much greater (by virtue of the use of DPA-triggered Tb luminescence instead of gold nanoparticles) than that of the prior lateral-flow immunoassay method

Ponce, Adrian

2003-01-01

219

Evanescent field response to immunoassay layer thickness on planar waveguides  

PubMed Central

The response of a compact photonic immunoassay biosensor based on a planar waveguide to variation in antigen (C-reactive protein) concentration as well as waveguide ridge height has been investigated. Near-field scanning optical microscope measurements indicate 1.7%?nm and 3.3%?nm top surface optical intensity modulation due to changes in effective adlayer thickness on waveguides with 16.5 and 10 nm ridge heights, respectively. Beam propagation method simulations are in good agreement with the experimental sensitivities as well as the observation of leaky mode interference both within and after the adlayer region.

Yan, Rongjin; Yuan, Guangwei; Stephens, Matthew D.; He, Xinya; Henry, Charles S.; Dandy, David S.; Lear, Kevin L.

2008-01-01

220

Diagnostic immunoassay by solid phase separation for digoxin  

SciTech Connect

A method is described for conducting a diagnostic immunoassay for digoxin, comprising: (a) forming a reaction mixture of a test sample with a molar excess of labeled anti-digoxin antibodies whereby the labeled antibodies are capable of forming complex with digoxin present in the sample; (b) contacting the reaction mixture with a solid phase material having immobilized thereon a compound; (c) separating the solid phase material from the reaction mixture; and (d) determining the presence of digoxin in the test sample by measuring the amount of complex present in the liquid phase.

Grenier, F.C.; Pry, T.A.; Kolaczkowski, L.

1988-11-29

221

ENA screen chemiluminescence immunoassay: a random access method in autoimmunology.  

PubMed

Recently, autoimmunity, due to an increase in examination requests, has become an independent area of laboratory research, which needs management optimization in terms of quality, time, and flexibility. Therefore, we have evaluated the screening of extractable nuclear antigens (ENA) antibodies both with a chemiluminescence immunoassay and the enzyme-linked immunosorbent assay (ELISA) method, which was used in our laboratory, as a reference kit. The most important difference between these two methods is the possibility of processing serum samples with a random access system, which is different from batch methods. PMID:17785312

Signorini, S; Kutschera, I; Capuano, F; Lattuada, L

2007-08-01

222

Demonstration of four immunoassay formats using the array biosensor  

NASA Technical Reports Server (NTRS)

The ability of a fluorescence-based array biosensor to measure and quantify the binding of an antigen to an immobilized antibody has been demonstrated using the four different immunoassay formats: direct, competitive, displacement, and sandwich. A patterned array of antibodies specific for 2,4,6-trinitrotoluene (TNT) immobilized onto the surface of a planar waveguide and used to measure signals from different antigen concentrations simultaneously. For direct, competitive, and displacement assays, which are one-step assays, measurements were obtained in real time. Dose-response curves were calculated for all four assay formats, demonstrating the array biosensor's ability to quantify the amount of antigen present in solution.

Sapsford, Kim E.; Charles, Paul T.; Patterson, Charles H Jr; Ligler, Frances S.

2002-01-01

223

Novel guidelines for organ donor cancer screening.  

PubMed

Donor transmitted malignancy is a real disastrous risk when dealing with expanded criteria donors. As donor age is increasing, guidelines for cancer screening of the elderly brain dead organ donors must be evidence-based but systematic review of such is sparse. Based on a review of published literature and our 20 years' experience, we propose a new series of guidelines concerning screening for the four most common malignancies: breast colon, lung and prostate cancer. Prospective testing of the efficacy of such protocol will then follow. PMID:24841765

Hassanain, Mazen

2014-01-01

224

Transperitoneal laparoscopic live donor nephrectomy: Current status.  

PubMed

Renal transplantation is the treatment of choice for a suitable patient with end stage renal disease. Unfortunately, the supply of donor organs is greatly exceeded by demand. In many countries the use of kidneys from living donors has been widely adopted as a partial solution. Traditionally donor nephrectomy has been performed via a open flank incision however with some morbidity like pain and a loin scar. Currently, the donor nephrectomy is increasingly being performed laparoscopically with the objective of reducing the morbidity. It is also hoped that this will lead to increasing acceptance of living donation. The first minimally invasive living donor nephrectomy was carried out in 1995 at the Johns Hopkins Medical Center and since then many centers have undertaken laparoscopic living donor nephrectomy. The laparoscopic approach substantially reduces the donor morbidity and wound related problems associated with open nephrectomy. The laparoscopic techniques thus have the potential to increase the number of living kidney donors. The present article attempts to review the safety and efficacy of transperitoneal laparoscopic donor nephrectomy. PMID:19718333

Srivastava, A; Gupta, N; Kumar, Anant; Kapoor, Rakesh; Dubey, Deepak

2007-07-01

225

Hybrid super electron donors - preparation and reactivity  

PubMed Central

Summary Neutral organic electron donors, featuring pyridinylidene–imidazolylidene, pyridinylidene–benzimidazolylidene and imidazolylidene–benzimidazolylidene linkages are reported. The pyridinylidene–benzimidazolylidene and imidazolylidene–benzimidazolylidene 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 pyridinylidene–imidazolylidene 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

2012-01-01

226

Living-donor liver transplantation: current perspective.  

PubMed

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

Lobritto, Steven; Kato, Tomoaki; Emond, Jean

2012-11-01

227

Pharmacokinetics of mycophenolic acid in live donor liver transplant patients vs deceased donor liver transplant patients.  

PubMed

The exposure of mycophenolic acid in live donor liver transplant patients (those receiving a partial hepatic volume) in comparison to deceased donor liver transplant patients (those receiving the whole hepatic volume) after administration of mycophenolate mofetil has not been reported earlier. The aim of the present study is to compare the pharmacokinetics parameters of mycophenolic acid and mycophenolic acid glucuronide in live donor liver transplant patients versus deceased donor liver transplant patients. Twelve live donor liver transplant and 12 deceased donor liver transplant recipients were studied over a dosing interval after intravenous administration of mycophenolate mofetil. The maximum concentration (Cmax) and the area under the plasma concentration versus time curve (AUC) for mycophenolic acid in live donor liver transplant patients were significantly higher than in deceased donor liver transplant patients (Cmax/AUC: live donor liver transplant patients: 16.1 +/- 6.6 microg/mL/43.9 +/- 12.6 microg/mL.h vs deceased donor liver transplant patients: 10.7 +/- 2.0 microg/mL/28.9 +/- 7.1 microg/mL.h; P = .046/.002). The volume of distribution was higher in the deceased donor liver transplant patients compared with live donor liver transplant patients. However, the mean plasma concentration at 12 hours (Clast), drug disposition rate constant, half-life (t 1/2), and mean residence time were similar in both groups. The mean plasma concentration of mycophenolic acid glucuronide was 1.4 to 2.0 times higher in deceased donor liver transplant patients compared with live donor liver transplant patients. These observations point to the need to use a lower dosage (approximately 30%) of mycophenolate mofetil in live donor liver transplant patients compared with deceased donor liver transplant patients. PMID:18440919

Jain, Ashok; Venkataramanan, Raman; Sharma, Rajeev; Kwong, Tai; Abt, Peter; Orloff, Mark; Kashyap, Randeep; Tsoulfas, Georgious; Bozorgzadeh, Adel

2008-05-01

228

[Dying with living donor transplantation].  

PubMed

A female patient with primary sclerosing cholangitis developed a cholangiocarcinoma (Klatskin tumor) at the age of 42 years. It was successfully resected by hemihepatectomy and hepaticojejunostomy. In the next 15 years she had recurrent episodes of bacterial cholangitis and had to be hospitalized several times a year for intravenous antibiotics. At the same time the sclerosing cholangitis progressed and she developed liver cirrhosis. The patient, who was never willing to give up, underwent liver transplantation by receiving the left liver lobe of her daughter (living donor). Postoperatively she suffered from severe complications including a biliary leak, sepsis, intraabdominal abscesses and cachexia. Soon after she was dismissed by the transplantation center, she was admitted to our hospital in a very poor condition. She refused any further intensive care and died, with the well functioning donated left liver lobe of the daughter dying with her. PMID:23188779

Reinhart, W

2012-12-01

229

Right hepatic lobe donation for living donor liver transplantation: Impact on donor quality of life  

Microsoft Academic Search

Adult right hepatic lobe living donor liver transplantation (LDLT) has rapidly gained widespread acceptance as an effective procedure for selected patients with end-stage liver disease. However, there are currently no published data on the effect of this procedure on the quality of life of donors. We report the results of a survey of our living liver transplant donors to determine

James F. Trotter; Michael Talamantes; Mary McClure; Michael Wachs; Thomas Bak; Thomas Trouillot; Marcelo Kugelmas; Gregory T. Everson; Igal Kam

2001-01-01

230

Pretransplant Infusion of Donor B Cells Enhances Donor-Specific Skin Allograft Survival  

PubMed Central

Pretransplant donor lymphocyte infusion (DLI) has been shown to enhance donor-specific allograft survival in rodents, primates and humans. However, the cell subset that is critical for the DLI effect and the mechanisms involved remain elusive. In this study, we monitored donor cell subsets after DLI in a murine MHC class I Ld-mismatched skin transplantation model. We found that donor B cells, but not DCs, are the major surviving donor APCs in recipients following DLI. Infusing donor B, but not non-B, cells resulted in significantly enhanced donor-specific skin allograft survival. Furthermore, mice that had received donor B cells showed higher expression of Ly6A and CD62L on antigen-specific TCR??+CD3+CD4?CD8?NK1.1? double negative (DN) regulatory T cells (Tregs). B cells presented alloantigen to DN Tregs and primed their proliferation in an antigen-specific fashion. Importantly, DN Tregs, activated by donor B cells, showed increased cytotoxicity toward anti-donor CD8+ T cells. These data demonstrate that donor B cells can enhance skin allograft survival, at least partially, by increasing recipient DN Treg-mediated killing of anti-donor CD8+ T cells. These findings provide novel insights into the mechanisms underlying DLI-induced transplant tolerance and suggest that DN Tregs have great potential as an antigen-specific immune therapy to enhance allograft survival.

Gao, Julia; McIntyre, Megan S. Ford.; D'Souza, Cheryl A.; Zhang, Li

2013-01-01

231

The Living Organ Donor Network: a model registry for living kidney donors.  

PubMed

The South-Eastern Organ Procurement Foundation presents the first report on a programme to track donors through questionnaires completed at the time of donation, 3 months, 6 months, and yearly thereafter. Donors at participating centres were eligible for an insurance policy with a total benefit of 250,000 US dollars, covering accidental death related to donation, surgery, medical expenses of complications, and disability income. The four participating centres have registered 104 donors. Response rate to the questionnaires was 90.91%. The majority of the donors come from the immediate family (81.62%), either by blood or marriage. The majority of donors are employed full time, with income ranges similar to the national census. Donors rely on employer-provided vacation time and sick leave to recuperate, but the average donor required 12 days of unpaid leave before returning to work. Donors also experienced costs of transportation, lodging, and childcare. Anti-depressants were prescribed to 10.58% of donors, and 4.8% of donors reported they are treated for hypertension. Complications were reported by 37.5% of the donors, but only 7.6% of the complications were serious enough to require hospitalization or surgery. Donors reported higher complication rates than reported by the centres and experience financial burdens afterwards. PMID:15217405

McCune, Thomas R; Armata, Thomas; Mendez-Picon, Gerardo; Yium, Jackson; Zabari, Gazi B; Crandall, Betty; Spicer, Helen G; Blanton, Jack; Thacker, Leroy R

2004-01-01

232

Aequorin fusion proteins as bioluminescent tracers for competitive immunoassays  

NASA Astrophysics Data System (ADS)

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.

Mirasoli, Mara; Michelini, Elisa; Deo, Sapna K.; Dikici, Emre; Roda, Aldo; Daunert, Sylvia

2004-06-01

233

Rapid immunoassay technique for process monitoring of animal cell fermentations.  

PubMed

A calibration and quality control technique suited to process monitoring with immunoassay is demonstrated. The particle concentration fluorescence immunoassay (PC-FIA) is shown to provide a sensitive and rapid method for the quantification of specific biomolecules in cell cultures. Smoothing of linear calibration parameters is performed by forming weighted averages of standard points as the run progresses. These estimates are then used to determine slope and intercept values for improved calibration. The nonuniformity of the fluorescent signal variance is also considered, and a weight model is developed to describe the relationship between signal fluorescence and signal variance for weighted linear curve fitting. Pooling calibration results over the process run improves overall assay performance as determined by using standard control chart analysis. This method is suitable for semicontinuous monitoring of animal cell fermentations and has been used here to measure cell-associated and culture supernatant concentrations of monoclonal antibody (Ab) from hybridoma cells. The cell-associated Ab concentration correlates with cell-specific production rate. Assay times on the order of 10 min for supernatant and 25-30 min for cell-associated Ab concentrations can be achieved, making this procedure suitable for process monitoring and control. Under these conditions the assay has a detection limit of approximately 10 ng/mL, providing a sensitive and specific method for the quantification of cell culture constituents. PMID:1366979

Jervis, E; Kilburn, D G

1991-01-01

234

Microsphere-based immunoassay for the detection of azaspiracids.  

PubMed

Azaspiracids (AZAs) are a group of lipophilic toxins discovered in mussels from Ireland in 1995 following a human poisoning incident. Nowadays the regulatory limit for AZAs in many countries is set at 160 ?g of azaspiracid equivalents per kilogram of shellfish meat. In this work a microsphere-based immunoassay has been developed for the detection of AZAs using a Luminex system. This method is based on the competition between AZA-2 immobilized onto the surface of microspheres and free AZAs for the interaction with a monoclonal anti-azaspiracid antibody (mAb 8F4). In this inhibition immunoassay the amount of mAb 8F4 bound to AZA-2 microspheres was quantified using a phycoerythrin-labeled anti-mouse antibody, and the fluorescence was measured with a Luminex analyzer. Simple acetate/methanol or methanol extractions yielded final extracts with no matrix interferences and adequate recovery rates of 86.5 and 75.8%, respectively. In summary, this work presents a sensitive and easily performed screening method capable of detecting AZAs at concentrations below the range of the European regulatory limit using a microsphere/flow cytometry system. PMID:24215909

Rodríguez, Laura P; Vilariño, Natalia; Louzao, M Carmen; Dickerson, Tobin J; Nicolaou, K C; Frederick, Michael O; Botana, Luis M

2014-02-15

235

A monoclonal immunoassay for the coplanar polychlorinated biphenyls.  

PubMed

Polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants with diverse toxic, teratogenic, reproductive, immunotoxic, and tumorigenic effects. Three of the least abundant of the 209 PCB isomers (congeners) are the most toxic and most difficult to quantify. These are 3,4,3',4'-tetrachlorobiphenyl, 3,4,3',4',5'-pentachlorobiphenyl, and 3,4,5,3',4',5'-hexachlorobiphenyl (IU-PAC No. 77, 126, and 169, respectively). An immunizing hapten was designed to retain the 3,4,3',4' chlorine-substitution pattern and coplanarity characteristic of these toxic congeners. The optimal competitors for immunoassay were weaker binding distinctive single-ring fragments of the PCBs. A monoclonal antibody designated S2B1 was derived and used in direct (antibody-capture) competitive enzyme immunoassays (EIAs). The EIAs are highly specific for non-ortho-substituted congeners and do not recognize the more prevalent but much less toxic noncoplanar PCB congeners or 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran, or dichlorobenzenes. Hapten and competitor design for this assay suggests a basis for development of sensitive EIAs for other classes of PCB congeners. PMID:8633754

Chiu, Y W; Carlson, R E; Marcus, K L; Karu, A E

1995-11-01

236

Finger-Actuated, Self-Contained Immunoassay Cassettes  

PubMed Central

The building blocks for an inexpensive, disposable, luminescence-based microfluidic immunoassay cassette are described, and their integration in a point-of-care diagnostic system is demonstrated. Fluid motion in the cassette is driven by depressing finger-actuated pouches. All reagents needed for the immunoassay can be stored in the cassette in liquid form. Prior to use, the cassette consists of two separate parts. A top storage component contains pouches, sealed storage chambers, a metering chamber, and needle seats. The bottom processing component contains connection needles, a mixing chamber, and a detection chamber with immobilized proteins. Subsequent to sample introduction, the storage and processing components are mated. The needles form hydraulic connections between the two parts and, in some cases, close valves. The pouches are then actuated sequentially to induce flow of various reagents and facilitate process operations. The cassette is compatible with different detection modalities. Both a cassette with immunochromatographic-based detection and a cassette with microbead-based detection were constructed and evaluated. The immunochromatographic cassette was used to detect antibodies to HIV in saliva samples. The bead-based cassette was used to detect the proinflammatory chemokine IL-8. The experimental data demonstrates good repeatability and reasonable sensitivity.

Qiu, Xianbo; Thompson, Jason A.; Chen, Zongyuan; Liu, Changchun; Chen, Dafeng; Ramprasad, Sudhir; Mauk, Michael G.; Ongagna, Serge; Barber, Cheryl; Abrams, William R.; Malamud, Daniel; Corstjens, Paul L.A.M.; Bau, Haim H.

2010-01-01

237

Optical scanner for immunoassays with up-converting phosphorescent labels.  

PubMed

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 microm, 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. x 10(4) microm(2) area and a dynamic range that covered more than three orders of magnitude. Utilizing this scanner, a microfluidic chip immunoassay for the cytokine interferon-gamma (IFN-gamma) was developed: concentrations as low as 3 pM (50 pg/mL) were detected from 100 microL samples with a total assay time of under an hour, including the 8 min readout. For this UCP-based assay, 2-D images of the capture antibody lines were scanned, image processing techniques were employed to extract the UCP emission signals, a response curve that spanned 3-600 pM IFN-gamma was generated, and a five-parameter logistic mathematical model was fitted to the data for determination of unknown IFN-gamma concentrations. Relative to common single-point or 1-D scanning optical measurements, our results suggest that a simple 2-D imaging system can speed assay development, reduce errors, and improve accuracy by characterizing the spatial distribution and uniformity of surface-captured optical labels as a function of assay conditions and device parameters. PMID:18440902

Li, Janice J; Ouellette, Amy L; Giovangrandi, Laurent; Cooper, David E; Ricco, Antonio J; Kovacs, Gregory T A

2008-05-01

238

Development of an Heterologous Immunoassay for Ciprofloxacin Residue in Milk  

NASA Astrophysics Data System (ADS)

A heterologous immunoassay has been developed for the determination of Ciprofloxacin (CPFX) residues in milk. For this reason, carbodiimide active ester method was employed to synthesize the artificial antigen of CPFX-BSA, and mixed anhydride reaction was used to prepare the coating antigen of CPFX-OVA to pursue the heterologous sensitivity. Based on the square matrix titration, an icELISA method was developed for the quantitative detection of CPFX in cattle milk. The dynamic range was from 0.036 to 92.5 ng/mL, with LOD and IC50 value of 0.019 ng/mL and 1.8 ng/mL, respectively. Except for a high cross-reactivity (89.7%) to Enrofloxacin, negligible cross-reactivity to the other compounds was observed. After optimization, 0.03 mol/L of HCl, or 10% of methanol was used in the assay buffer. 20-fold dilution in cattle milk gave an inhibition curve almost the same as that in PBS buffer. The regression equation for this assay was y = 0.9036 x + 1.4574, with a correlation coefficient (R2) of 0.9844. The results suggest the veracity of the heterologous immunoassay for detecting CPFX residue in milk.

Jinqing, Jiang; Haitang, Zhang; Zhixing, An; Zhiyong, Xu; Xuefeng, Yang; Huaguo, Huang; Ziliang, Wang

239

Sensitive Immunoassays of Nitrated Fibrinogen in Human Biofluids  

SciTech Connect

Three new sandwich immunoassays for detection of nitrated biomarker have been established with potential applications in biomedical studies and clinical practice. In this study, nitrated human fibrinogen, a potential oxidative stress biomarker for several pathologies, was chosen as the target. To improve the sensitivity and overcome the interference caused by the complexity of human biofluids, we developed three sandwich strategies using various combinations of primary antibody and secondary antibody. All three strategies demonstrated high sensitivity and selectivity towards nitrated forms of fibrinogen in buffer, but their performances were dramatically reduced when tested with human plasma and serum samples. Systematically optimizations were carried out to investigate the effects of numerous factors, including sampling, coating, blocking, and immunoreactions. Our final optimization results indicate that two of these strategies retain sufficient sensitivity and selectivity for use as assays in human physiological samples. Specifically, detection limits reached the pM level and the linear response ranges were up to nM level with a correlation coefficient > 0.99. To our best knowledge, this is the first example of using an electrochemical immunoassay for a nitrated biomarker in a physiological fluid. This novel approach provides a rapid, sensitive, selective, cost efficient and robust bioassay for detection of oxidative stress in pathology and for clinical applications. Moreover, the sandwich strategies developed in this paper can be readily used to establish effective methods targeting other nitration biomarkers.

Tang, Zhiwen; Wu, Hong; Du, Dan; Wang, Jun; Wang, Hua; Qian, Weijun; Bigelow, Diana J.; Pounds, Joel G.; Smith, Richard D.; Lin, Yuehe

2010-05-05

240

Quantum-Dots Based Electrochemical Immunoassay of Interleukin-1?  

SciTech Connect

We describe a quantum-dot (QD, CdSe@ZnS)-based electrochemical immunoassay to detect a protein biomarker, interleukin-1? (IL-1?). QD conjugated with anti-IL-1? antibody was used as a label in an immunorecognition event. After a complete sandwich immunoreaction among the primary IL-1? antibody (immobilized on the avidin-modified magnetic beads), IL-1?, and the QD-labeled secondary antibody, QD labels were attached to the magnetic-bead surface through the antibody-antigen immunocomplex. Electrochemical stripping analysis of the captured QDs was used to quantify the concentration of IL-1? after an acid-dissolution step. The streptavidin-modified magnetic beads and the magnetic separation platform were used to integrate a facile antibody immobilization (through a biotin/streptavidin interaction) with immunoreactions and the isolation of immunocomplexes from reaction solutions in the assay. The voltammetric response is highly linear over the range of 0.5 to 50 ng mL-1 IL 1?, and the limit of detection is estimated to be 0.3 ng mL-1 (18 pM). This QD-based electrochemical immunoassay shows great promise for rapid, simple, and cost-effective analysis of protein biomarkers.

Wu, Hong; Liu, Guodong; Wang, Jun; Lin, Yuehe

2007-07-01

241

Fast and Sensitive Detection of Bacillus anthracis Spores by Immunoassay  

PubMed Central

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.

Volland, Herve; Dano, Julie; Lamourette, Patricia; Sylvestre, Patricia; Mock, Michele; Creminon, Christophe

2012-01-01

242

Multiplex Detection of Plant Pathogens Using a Microsphere Immunoassay Technology  

PubMed Central

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.

Charlermroj, Ratthaphol; Himananto, Orawan; Seepiban, Channarong; Kumpoosiri, Mallika; Warin, Nuchnard; Oplatowska, Michalina; Gajanandana, Oraprapai; Grant, Irene R.; Karoonuthaisiri, Nitsara; Elliott, Christopher T.

2013-01-01

243

[Living donor kidney transplant: the surgical procedure].  

PubMed

The ideal nephrectomy technique for living donors should preserve donor safety and maximize graft quality for the recipient. The laparoscopic technique performs as well as the traditional open technique and has become the procedure of choice in up to 70% of the transplant centers in the US. Since November 2001, 70 living donor kidney transplants have been performed at the Transplant Center of Padua: 42 of the donors underwent laparoscopic left nephrectomy, 28 standard open nephrectomy. Donor and recipient results were analyzed retrospectively. After a mean follow-up of 38+/-26 months (laparoscopic group) and 40+/-27 months (open nephrectomy group) no deaths had occurred among the donors. Only one minor surgical complication was registered (hernia at the port site in a laparoscopic donor). Renal function was optimal in both groups of recipients, without significant differences in the incidence of delayed graft function and acute rejection. Minimally invasive approaches to donor nephrectomy are as safe and effective as the traditional open technique, minimizing postoperative pain and disability, and providing a better cosmetic result. PMID:19644840

Furian, L; Rigotti, Paolo

2009-01-01

244

21 CFR 610.41 - Donor deferral.  

Code of Federal Regulations, 2011 CFR

...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...

2011-04-01

245

Payment for donor kidneys: pros and cons.  

PubMed

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

Friedman, E A; Friedman, A L

2006-03-01

246

Kinetics of thermal donor generation in silicon  

NASA Technical Reports Server (NTRS)

The generation kinetics of thermal donors at 450 C in Czochralski-grown silicon was found to be altered by high-temperature preannealing (e.g., 1100 C for 30 min). Thus, when compared with as-grown Si, high-temperature preannealed material exhibits a smaller concentration of generated thermal donors and a faster thermal donor saturation. A unified mechanism of nucleation and oxygen diffusion-controlled growth (based on solid-state plate transformation theory) is proposed to account for generation kinetics of thermal donors at 450 C, in as-grown and high-temperature preannealed Czochralski silicon crystals. This mechanism is consistent with the main features of the models which have been proposed to explain the formation of oxygen thermal donors in silicon.

Mao, B.-Y.; Lagowski, J.; Gatos, H. C.

1984-01-01

247

Kinetic analyses and performance of a colloidal magnetic nanoparticle based immunoassay dedicated to allergy diagnosis.  

PubMed

In this paper, we demonstrate the possibility to use magnetic nanoparticles as immunosupports for allergy diagnosis. Most immunoassays used for immunosupports and clinical diagnosis are based on a heterogeneous solid-phase system and suffer from mass-transfer limitation. The nanoparticles' colloidal behavior and magnetic properties bring the advantages of homogeneous immunoassay, i.e., species diffusion, and of heterogeneous immunoassay, i.e., easy separation of the immunocomplex and free forms, as well as analyte preconcentration. We thus developed a colloidal, non-competitive, indirect immunoassay using magnetic core-shell nanoparticles (MCSNP) as immunosupports. The feasibility of such an immunoassay was first demonstrated with a model antibody and described by comparing the immunocapture kinetics using macro (standard microtiter plate), micro (microparticles) and nanosupports (MCSNP). The influence of the nanosupport properties (surface chemistry, antigen density) and of the medium (ionic strength, counter ion nature) on the immunocapture efficiency and specificity was then investigated. The performances of this original MCSNP-based immunoassay were compared with a gold standard enzyme-linked immunosorbent assay (ELISA) using a microtiter plate. The capture rate of target IgG was accelerated 200-fold and a tenfold lower limit of detection was achieved. Finally, the MCSNP-based immunoassay was successfully applied to the detection of specific IgE from milk-allergic patient's sera with a lower LOD and a good agreement (CV?

Teste, Bruno; Kanoufi, Frédéric; Descroix, Stéphanie; Poncet, Pascal; Georgelin, Thomas; Siaugue, Jean-Michel; Petr, Jan; Varenne, Anne; Hennion, Marie-Claire

2011-07-01

248

An extensive targeted proteomic analysis of disease-related protein biomarkers in urine from healthy donors.  

PubMed

The analysis of protein biomarkers in urine is expected to lead to advances in a variety of clinical settings. Several characteristics of urine including a low-protein matrix, ease of testing and a demonstrated proteomic stability offer distinct advantages over current widely used biofluids, serum and plasma. Improvements in our understanding of the urine proteome and in methods used in its evaluation will facilitate the clinical development of urinary protein biomarkers. Multiplexed bead-based immunoassays were utilized to evaluate 211 proteins in urines from 103 healthy donors. An additional 25 healthy donors provided serial urine samples over the course of two days in order to assess temporal variation in selected biomarkers. Nearly one-third of the evaluated biomarkers were detected in urine at levels greater than 1 ng/ml, representing a diverse panel of proteins with respect to structure, function and biological role. The presence of several biomarkers in urine was confirmed by western blot. Several methods of data normalization were employed to assess impact on biomarker variability. A complex pattern of correlations with urine creatinine, albumin and beta-2-microglobulin was observed indicating the presence of highly specific mechanisms of renal filtration. Further investigation of the urinary protein biomarkers identified in this preliminary study along with a consideration of the underlying proteomic trends suggested by these findings should lead to an improved capability to identify candidate biomarkers for clinical development. PMID:23723977

Nolen, Brian M; Orlichenko, Lidiya S; Marrangoni, Adele; Velikokhatnaya, Liudmila; Prosser, Denise; Grizzle, William E; Ho, Kevin; Jenkins, Frank J; Bovbjerg, Dana H; Lokshin, Anna E

2013-01-01

249

Hepatitis C antibody prevalence in blood donors in different governorates in Egypt.  

PubMed

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

1997-01-01

250

Donor Phosphorus Levels and Recipient Outcomes in Living-Donor Kidney Transplantation  

PubMed Central

Summary Background and objectives In living-donor kidney transplantation, various donor factors, including gender, age, and baseline kidney function, predict allograft function and recipient outcomes after transplantation. Because higher phosphorus is predictive of vascular injury in healthy adults, the effect of donor phosphorus levels on recipient renal function after transplantation was investigated. Design, setting, participants, and measurements Phosphorus levels in 241 living donors were analyzed from a 7-year period, and recipient renal function and acute rejection at 1 year posttransplantation were examined controlling for other influencing factors, including multiple donor variables, HLA matching, and acute rejection. Results Female and African-American donors had significantly higher phosphorus levels predonation. By multivariable analysis, higher donor phosphorus correlated with higher recipient serum creatinine (slope = 0.087, 95% confidence interval [CI]: 0.004 to 0.169, P = 0.041) and lower recipient estimated GFR (slope = ?4.321, 95% CI: ?8.165 to ?0.476, P = 0.028) at 12 months. Higher donor phosphorus also displayed an independent correlation with biopsy-proven acute rejection and delayed or slow graft function after transplantation. Conclusions In a cohort of living kidney donors, higher donor phosphorus correlated with female gender and African-American ethnicity and was an independent risk factor for early allograft dysfunction after living-donor kidney transplantation.

Chang, Peter C.; Saha, Sharmeela; Gomes, Amanda M.; Padiyar, Aparna; Bodziak, Kenneth A.; Poggio, Emilio D.; Hricik, Donald E.

2011-01-01

251

Europium Nanoparticle-Based High Performing Immunoassay for the Screening of Treponemal Antibodies  

PubMed Central

Treponema pallidum subspecies pallidum (Tp) is the causative agent of syphilis which mainly spreads through sexual contact, blood transfusion and perinatal route. In order to curtail the spread of the infection and to clinically manage the disease, timely, accurate and reliable diagnosis is very important. We have developed an immunoassay for the detection of treponemal antibodies in human serum or plasma samples. In vivo biotinylated and non-biotinylated versions of the recombinant antigen were designed by the fusion of three Tp-specific antigens namely Tp15, Tp17 and Tp47. These fusion antigens were expressed in E. coli and purified using single-step metal affinity chromatography. Biotinylated fusion antigen immobilized on streptavidin coated plate was used to capture the treponemal antibodies and the non-biotinylated antigen coated on europium nanoparticles was used as tracer. Assays with two different incubation times of 10 min and 1 h were developed, and following the incubation the europium fluorescence was measured using time-resolved fluorometry. The developed time-resolved fluorometric (TRF) immunoassays were evaluated with in-house and commercial serum/plasma sample panels. For well-established treponemal antibodies positive or negative samples, the sensitivity of TRF immunoassay with 10 min incubation time was 97.4%, and of TRF immunoassay with 1 h incubation time was 98.7%, and the specificities of both the TRF immunoassays were 99.2%. For the samples with discordant results with the reference assays, both the TRF immunoassays showed better specificity than the Enzygnost syphilis enzyme immunoassay as a screening test. The two different incubation times did not have any significant effect on the signal to cutoff (S/Co) ratios obtained with the two immunoassays (p?=?0.06). Our results indicate that the developed immunoassay with a short incubation time of 10 min has the potential to be used in clinical laboratories and in blood-bank settings as a screening test for treponemal antibodies.

Talha, Sheikh M.; Hytonen, Jukka; Westhorpe, Adam; Kumar, Sushil; Khanna, Navin; Pettersson, Kim

2013-01-01

252

Europium nanoparticle-based high performing immunoassay for the screening of treponemal antibodies.  

PubMed

Treponema pallidum subspecies pallidum (Tp) is the causative agent of syphilis which mainly spreads through sexual contact, blood transfusion and perinatal route. In order to curtail the spread of the infection and to clinically manage the disease, timely, accurate and reliable diagnosis is very important. We have developed an immunoassay for the detection of treponemal antibodies in human serum or plasma samples. In vivo biotinylated and non-biotinylated versions of the recombinant antigen were designed by the fusion of three Tp-specific antigens namely Tp15, Tp17 and Tp47. These fusion antigens were expressed in E. coli and purified using single-step metal affinity chromatography. Biotinylated fusion antigen immobilized on streptavidin coated plate was used to capture the treponemal antibodies and the non-biotinylated antigen coated on europium nanoparticles was used as tracer. Assays with two different incubation times of 10 min and 1 h were developed, and following the incubation the europium fluorescence was measured using time-resolved fluorometry. The developed time-resolved fluorometric (TRF) immunoassays were evaluated with in-house and commercial serum/plasma sample panels. For well-established treponemal antibodies positive or negative samples, the sensitivity of TRF immunoassay with 10 min incubation time was 97.4%, and of TRF immunoassay with 1 h incubation time was 98.7%, and the specificities of both the TRF immunoassays were 99.2%. For the samples with discordant results with the reference assays, both the TRF immunoassays showed better specificity than the Enzygnost syphilis enzyme immunoassay as a screening test. The two different incubation times did not have any significant effect on the signal to cutoff (S/Co) ratios obtained with the two immunoassays (p=0.06). Our results indicate that the developed immunoassay with a short incubation time of 10 min has the potential to be used in clinical laboratories and in blood-bank settings as a screening test for treponemal antibodies. PMID:24386329

Talha, Sheikh M; Hytönen, Jukka; Westhorpe, Adam; Kumar, Sushil; Khanna, Navin; Pettersson, Kim

2013-01-01

253

Correlation between donor age and organs transplanted per donor: our experience in Japan.  

PubMed

The shortage of available organs for transplantation is a worldwide issue. To maximize the number of transplantations, increasing the number of organs transplanted per donor (OTPD) is widely recognized as an important factor for improving the shortage. In Japan, we have had 211 donors, 1112 organs transplanted, and 924 recipients receiving the transplants, resulting in 4.4 ± 1.4 recipients receiving transplants per donor and 5.3 ± 1.6 OTPD as of February 2013. Because donor age is a well-recognized factor of donor suitability, we analyzed the correlation between donor age group and OTPD. Only the age group 60 to 69 years and the age group 70 to 79 years were significantly different (P < .05) from adjacent age groups. We estimate that a donor under age 70 years has the potential to donate 4.6 to 6.7 organs. PMID:24815124

Ashikari, J; Omiya, K; Konaka, S; Nomoto, K

2014-05-01

254

Gamete donors' satisfaction; gender differences and similarities among oocyte and sperm donors in a national sample  

PubMed Central

ObjectiveTo explore oocyte and sperm donors' emotional stress, experiences of care and satisfaction after donation. DesignProspective multicenter study. SettingsAll fertility clinics performing gamete donation in Sweden during the period 2005 to 2008. PopulationOf 220 eligible oocyte donors who were approached, 181 agreed to complete the first questionnaire and 165 completed the second questionnaire 2?months after oocyte donation. Of 156 eligible sperm donors 119 accepted to complete the first questionnaire before donation. Eighty-nine participants completed the second questionnaire 2?months after sperm donation. MethodsStandardized and study-specific questionnaires. Main outcome measuresSatisfaction with the donation, respondents' mental health and overall care. ResultsA larger percentage of sperm donors (97.8%) were satisfied with their overall experience of being a donor than oocyte donors (85.9%, p?=?0.003). Some oocyte and sperm donors did not receive sufficient information about practical issues (9.1% and 13.5%, respectively) and future consequences (12.8% and 3.4%, respectively, p?=?0.014). The donors' symptoms of anxiety and depression did not show any differences in relation to negative or positive perceptions of satisfaction. The donors who did not indicate ambivalence before treatment were on average almost five times more satisfied compared with those who did indicate ambivalence (odds ratio 4.71; 95% CI 1.34–16.51). ConclusionsMost donors were satisfied with their contribution after the donation. Oocyte and sperm donors who expressed ambivalence before donation were less satisfied after donation. In vitro fertilization staff fulfilled most of the donors' needs for information and care. Please cite this article as: Skoog Svanberg A, Lampic C, Gejerwall A-L, Gudmundsson J, Karlström P-O, Solensten N-G, Sydsjö G. Gamete donors’ satisfaction; gender differences and similarities among oocyte and sperm donors in a national sample. Acta Obstet Gynecol Scand 2013; 92:1049–1056.

Svanberg, Agneta Skoog; Lampic, Claudia; Gejerwall, Ann-Louise; Gudmundsson, Johannes; Karlstrom, Per-olof; Solensten, Nils-Gunnar; Sydsjo, Gunilla

2013-01-01

255

Development of a Disperse Dye Immunoassay Technique for Detection of Antibodies against Neospora caninum in Cattle  

PubMed Central

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

2013-01-01

256

A Consideration of Some Correlates of Fainting in Blood Donors.  

National Technical Information Service (NTIS)

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...

L. J. Misantone

1970-01-01

257

21 CFR 640.31 - Suitability of donors.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Plasma § 640.31 Suitability of donors. (a) Whole blood donors shall meet the criteria for donor suitability prescribed...

2010-04-01

258

21 CFR 640.31 - Suitability of donors.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Plasma § 640.31 Suitability of donors. (a) Whole blood donors shall meet the criteria for donor suitability prescribed...

2012-04-01

259

21 CFR 640.31 - Suitability of donors.  

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Plasma § 640.31 Suitability of donors. (a) Whole blood donors shall meet the criteria for donor suitability prescribed...

2014-04-01

260

21 CFR 640.31 - Suitability of donors.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Plasma § 640.31 Suitability of donors. (a) Whole blood donors shall meet the criteria for donor suitability prescribed...

2011-04-01

261

21 CFR 640.12 - Suitability of donor.  

Code of Federal Regulations, 2011 CFR

...CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.12 Suitability of donor. The source blood for Red Blood Cells shall be obtained from a donor who meets the criteria for donor...

2011-04-01

262

21 CFR 660.31 - Suitability of the donor.  

Code of Federal Regulations, 2011 CFR

...ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.31 Suitability of the donor. Donors of peripheral blood for Reagent Red Blood Cells shall meet the criteria for donor suitability under §...

2011-04-01

263

A high-throughput homogeneous immunoassay based on Förster resonance energy transfer between quantum dots and gold nanoparticles.  

PubMed

A novel homogeneous immunoassay based on Förster resonance energy transfer for sensitive detection of tumor, e.g., marker with carcinoembryonic antigen (CEA), was proposed. The assay was consisted of polyclonal goat anti-CEA antibody labeled luminescent CdTe quantum dots (QDs) as donor and monoclonal goat anti-CEA antibody labeled gold nanoparticles (AuNPs) as acceptor. In presence of CEA, the bio-affinity between antigen and antibody made the QDs and AuNPs close enough, thus the photoluminescence (PL) quenching of CdTe QDs occurred. The PL properties could be transformed into the fluorometric variation, corresponding to the target antigen concentration, and could be easily monitored and analyzed with the home-made image analysis software. The fluorometric results indicated a linear detection range of 1-110 ng mL(-1) for CEA, with a detection limit of 0.3 ng mL(-1). The proposed assay configuration was attractive for carcinoma screening or single sample in point-of-care testing, and even field use. In spite of the limit of available model analyte, this approach could be easily extended to detection of a wide range of biomarkers. PMID:23340285

Qian, Jing; Wang, Chengquan; Pan, Xiaohu; Liu, Songqin

2013-02-01

264

Efficacies of US Food and Drug Administration-licensed HIV-1-screening enzyme immunoassays for detecting antibodies to HIV-2.  

PubMed

To determine the efficacy of enzyme immunoassays (EIAs) for antibodies against HIV-1 in detecting HIV-2-infected blood, we tested 55 HIV-2-positive sera with seven Food and Drug Administration-licensed EIA kits. The percentage detection of HIV-2 sera giving positive reactions with these kits varied between the various manufacturers from 60 to 91%. Observations based on a small number of sera (n = 13), suggest that HIV-2-positive blood collected from apparently healthy people (blood donors, prenatal clinics) are detected with a greater frequency (means = 89%) than blood from AIDS patients or patients (n = 32) hospitalized with other infectious diseases (means = 72%). Based on these results and the low incidence of HIV-2 infection observed in the USA, it was concluded that screening with HIV-2-specific tests would not significantly increase the number of HIV-2-positive people detected by current screening programs. However, due to the poor sensitivity of certain HIV-1 assays for HIV-2 antibodies, HIV-2 sera without cross-reacting antibodies will escape detection. Surveillance for HIV-2 might then be improved by the availability of HIV-1 and HIV-2 combination assays. PMID:2350452

George, J R; Rayfield, M A; Phillips, S; Heyward, W L; Krebs, J W; Odehouri, K; Soudre, R; De Cock, K M; Schochetman, G

1990-04-01

265

Fluorescence immunoassay of octachlorostyrene based on Förster resonance energy transfer between CdTe quantum dots and rhodamine B.  

PubMed

Octachlorostyrene (OCS), a persistent and bioaccumulative toxicant (PBT), was assayed by fluorescence immunoassay based on the Förster resonance energy transfer (FRET) between CdTe quantum dots (QDs) and rhodamine B-labeled OCS (RB-OCS). Anti-OCS antibody produced in this lab is adsorbed on a microtiter plate. The RB-OCS competes with OCS for the highly specific immunoreaction with the anti-OCS antibodies adsorbed on the microtiter plate. The solution is then isolated and mixed with CdTe QDs as fluorescent donor which excite the emission of RB-OCS through FRET. As a result, the emission of CdTe QDs at 530 nm decreases, whereas the emission of RB-OCS at 580 nm increases. The ratio of fluorescence intensity at 580 nm to that at 530 nm is proportional to the RB-OCS concentration at a fixed CdTe QDs concentration, and consequently proportional to the OCS concentration. Selective and sensitive responses to OCS are achieved with a linear range of 8-80 nM and a LOD of 3.8 nM. Because OCS is quantified based on the fluorescence ratio, the sensor-to-sensor difference is greatly eliminated, making the proposed method a useful approach for in site scanning of OCS. PMID:24768862

Wang, Xin; Sheng, Pengtao; Zhou, Liping; Tong, Xi; Shi, Lei; Cai, Qingyun

2014-10-15

266

Donor deactivation in silicon nanostructures.  

PubMed

The operation of electronic devices relies on the density of free charge carriers available in the semiconductor; in most semiconductor devices this density is controlled by the addition of doping atoms. As dimensions are scaled down to achieve economic and performance benefits, the presence of interfaces and materials adjacent to the semiconductor will become more important and will eventually completely determine the electronic properties of the device. To sustain further improvements in performance, novel field-effect transistor architectures, such as FinFETs and nanowire field-effect transistors, have been proposed as replacements for the planar devices used today, and also for applications in biosensing and power generation. The successful operation of such devices will depend on our ability to precisely control the location and number of active impurity atoms in the host semiconductor during the fabrication process. Here, we demonstrate that the free carrier density in semiconductor nanowires is dependent on the size of the nanowires. By measuring the electrical conduction of doped silicon nanowires as a function of nanowire radius, temperature and dielectric surrounding, we show that the donor ionization energy increases with decreasing nanowire radius, and that it profoundly modifies the attainable free carrier density at values of the radius much larger than those at which quantum and dopant surface segregation effects set in. At a nanowire radius of 15 nm the carrier density is already 50% lower than in bulk silicon due to the dielectric mismatch between the conducting channel and its surroundings. PMID:19197312

Björk, Mikael T; Schmid, Heinz; Knoch, Joachim; Riel, Heike; Riess, Walter

2009-02-01

267

Medical outcomes of adolescent live kidney donors.  

PubMed

Living kidney donation from donors <18 yr of age is uncommon. The majority of donations from adolescents took place several decades ago providing a unique opportunity to study true long-term consequences of donation. We compared survival, renal outcomes, and rates of hypertension and diabetes among 42 adolescent donors and matched older controls. Adolescent donors were matched with donors 18-30 yr on the following: gender, relation to the recipient, BMI at donation, eGFR at donation, and year of donation. After a mean follow-up of 31.8 ± 8.0 yr, 94.9% of adolescent donors were alive vs. 93.8% of controls. There was no significant difference in having eGFR (MDRD) <60 mL/min/1.73 m(2) (26.1% vs. 40.9%), hypertension (35.9% vs. 39.4%), diabetes (5.1% vs. 12.5%), or proteinuria (15.4% vs. 14.1%): adolescent donors vs. controls for all comparisons. These data suggest that adolescent donors are not at a higher risk of shortened survival, hypertension, diabetes, or proteinuria. Nevertheless, they probably should donate only when other options are exhausted as they have to live with a single kidney for decades and longer follow-up is needed. PMID:24646177

Macdonald, David; Kukla, Aleksandra K; Ake, Sarah; Berglund, Danielle; Jackson, Scott; Issa, Naim; Spong, Richard; Matas, Arthur J; Ibrahim, Hassan N

2014-06-01

268

Complications in 100 living-liver donors.  

PubMed Central

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

1998-01-01

269

A capillary electrophoresis laser-induced fluorescence method for analysis of potato glycoalkaloids based on a solution-phase immunoassay. 1. Separation and quantification of immunoassay products.  

PubMed

Solution-phase immunoassays are typically faster and more precise than ELISAs. This research developed a solution-phase for the immunoassay of potato glycoalkaloids (GAs) based on quantification by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection. Solanidine coupled to 4'-(aminomethyl)fluorescein and a polyclonal antibody solution were used as the immunoreagents. Unbound fluorescent solanidine was detected by CE-LIF (excitation 488 nm, emission 520 nm). Optimum resolution of immunoassay products was achieved with a buffer consisting of 50 mM phosphate, 10% (v/v) methanol, and 1.5 mM SDS, pH 7.5. A plot of signal vs log [GA] produced a sigmoidal curve typical of immunoassays. Analysis of extracts of sprouted Yukon Gold potato tubers and nonsprouted Yukon Gold tubers resulted in total [GA] of 98 microg/g (RSD 9%) and 55 microg/g (RSD 9%), respectively. The findings indicated that CE-LIF coupled with a solution-phase immunoassay can be used to quantify total GA in potatoes. PMID:10775362

Driedger, D R; LeBlanc, R J; LeBlanc, E L; Sporns, P

2000-04-01

270

Right hepatic lobe donation for living donor liver transplantation: impact on donor quality of life.  

PubMed

Adult right hepatic lobe living donor liver transplantation (LDLT) has rapidly gained widespread acceptance as an effective procedure for selected patients with end-stage liver disease. However, there are currently no published data on the effect of this procedure on the quality of life of donors. We report the results of a survey of our living liver transplant donors to determine the effect of right hepatic lobe donation on quality of life. We have performed 30 LDLTs since 1997; 24 of these have a follow-up of 4 months or longer. In August 2000, these patients were sent a questionnaire (including a Medical Outcomes Study 36-Item Short-Form Survey) regarding psychosocial outcomes and symptoms after surgery. Major complications occurred in 4 of 24 patients (16%), and minor complications, in 4 of 24 patients (16%). Complete recovery occurred in 75% of patients at a mean time of 3.4 months. Ninety-six percent of patients returned to the same predonation job after a mean time of 2.4 months, and 66% of patients required a period of light-duty work for a mean of 2.8 months before returning to full-duty work. A change in body image was reported in 42% of patients, and 71% reported mild ongoing symptoms (primarily abdominal discomfort) that they related to the donor surgery for which 29% sought evaluation by a physician. The donor's relationship with the recipient was the same or better in 96% of donors, and the relationship with the donor's significant other was the same or better in 88% of donors. Mean out-of-pocket expenses incurred by donors were $3,660. Sixty-three percent of donors reported experiencing more pain than anticipated. All patients would donate again if necessary, and 96% benefited from the donor experience. In conclusion, (1) all our donors are alive and well after donation; (2) almost all donors were able to return to predonation employment status within a few months; (3) most donors have mild persistent abdominal symptoms, and some donors had a change in body image that they attribute to the donor surgery; and (4) this information should be provided to potential donors so they may better understand the impact of donor surgery. PMID:11443574

Trotter, J F; Talamantes, M; McClure, M; Wachs, M; Bak, T; Trouillot, T; Kugelmas, M; Everson, G T; Kam, I

2001-06-01

271

On-Chip Immunoassay for Determination of Urinary Albumin  

PubMed Central

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 L–1 (r2 = 0.993), with a detection limit of 0.81 mg L–1 (S/N = 3). The proposed system showed good precision, with relative standard deviations (RSDs) of 5.1%, when evaluated with 10 mg L–1 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).

Laiwattanapaisal, Wanida; Songjaroen, Temsiri; Maturos, Thitima; Lomas, Tanom; Sappat, Assawapong; Tuantranont, Adisorn

2009-01-01

272

Fluorescence immunoassay based on long time correlations of number fluctuations.  

PubMed Central

We report the development of a fluorescence-based immunoassay technique relying on the physical phenomena of random number fluctuations and diffusion, which we review. By determining the autocorrelation of the fluctuations in the fluorescent intensity, this methid is able to measure the amount of labeled antigen or antibody that is bound to micrometer-sized carrier particles in solution. The principal advantage of this technique is its insensitivity to small, fast-diffusing sources. It also discriminates against weakly fluorescent contaminants of size comparable to the carrier particles. We demonstrate these attributes by using two model systems: a human IgG assay and an idealized system consisting of polystyrene fluorescent spheres and rhodamine dye.

Nicoli, D F; Briggs, J; Elings, V B

1980-01-01

273

Determination of theophylline concentration in serum by chemiluminescent immunoassay  

PubMed Central

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.

Zhou, Mei-xia; Guan, Cha-ying; Chen, Guang; Xie, Xin-you; Wu, Sheng-hai

2005-01-01

274

Chemiluminescence enzyme immunoassay for the determination of sulfamethoxydiazine.  

PubMed

Sulfamethoxydiazine (SMD), which is often used for animal disease treatment, is harmful to human health. No SMD residue should be detected in food in some countries, such as USA and Japan. Therefore, it is significant to develop a high-throughput, high-sensitivity and accurate method for the determination of the content of SMD in food. In this paper, chemiluminescence enzyme immunoassay (CLEIA) was developed for quantification of SMD. For this method, the limit of detection was 3.2 pg/ml, the linear range was from 10 to 2000 pg/ml, the within-day and inter-day precision were below 13% and below 18%, respectively, and the recovery was from 85% to 105%. Milk and egg were selected as samples to be examined with this method, and the result indicated that this CLEIA method was suitable for screening and quality control of food. PMID:21795101

Wu, Yongjun; Yu, Songcheng; Yu, Fei; Yan, Nali; Qu, Lingbo; Zhang, Hongquan

2011-10-15

275

Novel shell/core particles for automated turbidimetric immunoassays.  

PubMed

Recent innovations in particle design have led to the development of highly sensitive and reproducible immunoassay methods for the Du Pont aca discrete clinical analyzer. Key advances include the synthesis and use of particles less than 1 micron in diameter with high refractive index cores surrounded by thin, chemically reactive shells. The cores are prepared by emulsion polymerization to a well-defined size that depends on the choice of monomer and the requirements for turbidimetric signal. Methods for measuring therapeutic drugs (e.g., theophylline) involve particles with polystyrene cores; other methods require cores with higher refractive indices such as polyvinylnaphthalene. The shells are critical for overall method performance because they bind covalently the immunochemicals of interest. Polyglycidyl methacrylate shells have been used effectively to attach antigens and haptens to the particle surface. PMID:6467565

Litchfield, W J; Craig, A R; Frey, W A; Leflar, C C; Looney, C E; Luddy, M A

1984-09-01

276

Nanoscale fluoro-immunoassays with lanthanide oxide nanoparticles  

NASA Astrophysics Data System (ADS)

The use of polystyrene nanoparticles with europium chelate has been demonstrated as fluorescent reporters in an immunoassay for atrazine. The limit of detection with the nanoparticles was similar to that achieved with a conventional ELISA. It was shown that as the particle size decreased the time required for binding decreased and the sensitivity of the assay increased. This suggests that the use of smaller particles would greatly speed up the reaction and simultaneously increase sensitivity. However, the detection system used sets limits to the particle size as well. There is clearly a point where our detection system would not be sensitive enough to detect the emission from small particles. Therefore, a highly sensitive excitation/detection system needs to be developed to fully utilize the kinetic advantage from small particle size.

Kennedy, Ian M.; Koivunen, Marja M.; Gee, Shirley M.; Cummins, Craig M.; Perron, Richard M.; Dosev, Dosi M.; Hammock, Bruce D.

2004-12-01

277

Detection of Molecular signatures of life using immunoassay techniques  

NASA Astrophysics Data System (ADS)

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.

278

Chemiluminescence enzyme immunoassay for the determination of sulfamethoxydiazine  

NASA Astrophysics Data System (ADS)

Sulfamethoxydiazine (SMD), which is often used for animal disease treatment, is harmful to human health. No SMD residue should be detected in food in some countries, such as USA and Japan. Therefore, it is significant to develop a high-throughput, high-sensitivity and accurate method for the determination of the content of SMD in food. In this paper, chemiluminescence enzyme immunoassay (CLEIA) was developed for quantification of SMD. For this method, the limit of detection was 3.2 pg/ml, the linear range was from 10 to 2000 pg/ml, the within-day and inter-day precision were below 13% and below 18%, respectively, and the recovery was from 85% to 105%. Milk and egg were selected as samples to be examined with this method, and the result indicated that this CLEIA method was suitable for screening and quality control of food.

Wu, Yongjun; Yu, Songcheng; Yu, Fei; Yan, Nali; Qu, Lingbo; Zhang, Hongquan

2011-10-01

279

Thermal double donors and quantum dots.  

PubMed

Combined local mode spectroscopy and ab initio modeling are used to demonstrate for the first time that oxygen atoms in thermal double donors (TDD) in Si are in close proximity. The observed vibrational modes in (16)O, (18)O, and mixed isotopic samples are consistent with a model involving [110] aligned oxygen chains made up of an insulating core lying between electrically active ends. The model also explains the minute spin density observed on oxygen in TDD(+) as well as the piezospectroscopic tensors of the donors. The analogy between the thermal donors and quantum dots is emphasized. PMID:11736458

Coutinho, J; Jones, R; Murin, L I; Markevich, V P; Lindström, J L; Oberg, S; Briddon, P R

2001-12-01

280

Interventional radiology in living donor liver transplant  

PubMed Central

The shortage of deceased donor liver grafts led to the use of living donor liver transplant (LDLT). Patients who undergo LDLT have a higher risk of complications than those who undergo deceased donor liver transplantation (LT). Interventional radiology has acquired a key role in every LT program by treating the majority of vascular and non-vascular post-transplant complications, improving graft and patient survival and avoiding, in the majority of cases, surgical revision and/or re-transplant. The aim of this paper is to review indications, diagnostic modalities, technical considerations, achievements and potential complications of interventional radiology procedures after LDLT.

Cheng, Yu-Fan; Ou, Hsin-You; Yu, Chun-Yen; Tsang, Leo Leung-Chit; Huang, Tung-Liang; Chen, Tai-Yi; Hsu, Hsien-Wen; Concerjero, Allan M; Wang, Chih-Chi; Wang, Shih-Ho; Lin, Tsan-Shiun; Liu, Yueh-Wei; Yong, Chee-Chien; Lin, Yu-Hung; Lin, Chih-Che; Chiu, King-Wah; Jawan, Bruno; Eng, Hock-Liew; Chen, Chao-Long

2014-01-01

281

Current research on organ donor management.  

PubMed

A shortage of organs is available for transplantation, with 116,000 patients on the Organ Procurement and Transplantation Network/United Network for Organ Sharing wait list. Because the demand for organs outweighs the supply, considerable care must be taken to maximize the number of organs transplanted per donor and optimize the quality of recovered organs. Studies designed to determine optimal donor management therapies are limited, and this research has many challenges. Although evidenced-based guidelines for managing potential organ donors do not exist, research in this area is increasing. This article reviews the existing literature and highlights recent trials that can guide management. PMID:24287350

Sally, Mitchell; Malinoski, Darren

2013-12-01

282

Feelings of living donors about adult-to-adult living donor liver transplantation.  

PubMed

This study investigated the feelings of living donors about adult-to-adult liver transplantation. We interviewed 18 donors about their feelings before and after transplantation using semistructured interviews and then conducted a content analysis of their responses. Before transplantation, many donors reported that they wanted recipients to live for the donor or his or her family, and there was no one else to donate. Many donors were not anxious, did not feel coerced, and did not consider donation dangerous. Some reported being excited at facing a new experience. Some said they would not mind whatever happens. Others were anxious or unsure about the operation. Diagnostic testing and preoperative blood banking were painful. Donors experienced increasing stress just before the operation. After transplantation, some donors verbalized feeling more grateful to others and that they gained maturity. Throughout the process, donors were concerned about their recipients. Our results suggest that donors might act for themselves or their family. It is important to recognize the varied responses of donors' feelings toward liver transplant recipients. PMID:18708830

Kusakabe, Tomoko; Irie, Shinji; Ito, Naomi; Kazuma, Keiko

2008-01-01

283

Multiplexed magnetic microsphere immunoassays for detection of pathogens in foods  

PubMed Central

Foodstuffs have traditionally been challenging matrices for conducting immunoassays. Proteins, carbohydrates, and other macromolecules present in food matrices may interfere with both immunoassays and PCR-based tests, and removal of particulate matter may also prove challenging prior to analyses. This has been found true when testing for bacterial contamination of foods using the standard polystyrene microspheres utilized with Luminex flow cytometers. Luminex MagPlex microspheres are encoded with the same dyes as standard xMAP microspheres, but have superparamagnetic properties to aid in preparation of samples in complex matrices. In this work, we present results demonstrating use of MagPlex for sample preparation and identification of bacteria and a toxin spiked into a variety of food samples. Fluorescence-coded MagPlex microsphere sets coated with antibodies for Salmonella, Campylobacter, Escherichia coli, Listeria, and staphylococcal enterotoxin B (SEB) were used to capture these bacteria and toxin from spiked foodstuffs and then evaluated by the Luminex system in a multiplex format; spiked foods included apple juice, green pepper, tomato, ground beef, alfalfa sprouts, milk, lettuce, spinach, and chicken washes. Although MagPlex microspheres facilitated recovery of the microspheres and targets from the complex matrices, assay sensitivity was sometimes inhibited by up to one to three orders of magnitude; for example the detection limits E. coli spiked into apple juice or milk increased 100-fold, from 1000 to 100,000 cfu/mL. Thus, while the magnetic and fluorescent properties of the Luminex MagPlex microspheres allow for rapid, multiplexed testing for bacterial contamination in typically problematic food matrices, our data demonstrate that achieving desired limits of detection is still a challenge.

Kim, Jason S.; Taitt, Chris R.; Ligler, Frances S.

2010-01-01

284

Concentration gradient immunoassay. 2. Computational modeling for analysis and optimization.  

PubMed

A novel microfluidic surface-based competition immunoassay, termed the concentration gradient immunoassay (described in detail in a companion paper (Nelson, K.; Foley, J.; Yager, P. Anal. Chem. 2007, 79, 3542-3548.) uses surface plasmon resonance (SPR) imaging to rapidly measure the concentration of small molecules. To conduct this assay, antibody and analyte are introduced into the two inlets of a T-sensor (Weigl, B. H.; Yager, P. Science 1999, 283, 346-347. Kamholz, A. E.; Weigl, B. H.; Finlayson, B. A.; Yager, P. Anal. Chem. 1999, 71, 5340-5347). Several millimeters downstream, antibody molecules with open binding sites can bind to a surface functionalized with immobilized antigen. This space- and time-dependent binding can be sensitively observed using SPR imaging. In this paper, we describe a complex three-dimensional finite element model developed to better understand the dynamic processes occurring with this assay. The model shows strong qualitative agreement with experimental results for small-molecule detection. The model confirms the experimental finding that the position within the microchannel at which the antibody binds to the immobilized analyte may be used to quantify the concentration of analyte in the sample. In addition, the model was used to explore the sensitivity of assay performance to parameters such as antibody and analyte concentrations, thereby giving insight into ways to optimize analysis speed and accuracy. Given the experimental verification of the computational results, this model serves as an efficient method to explore the influence of the flow rate, microchannel dimensions, and antibody concentration on the sensitivity of the assay. PMID:17437333

Foley, Jennifer O; Nelson, Kjell E; Mashadi-Hossein, Afshin; Finlayson, Bruce A; Yager, Paul

2007-05-15

285

Donor conceived offspring conceive of the donor: the relevance of age, awareness, and family form.  

PubMed

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

Hertz, Rosanna; Nelson, Margaret K; Kramer, Wendy

2013-06-01

286

Psychosocial Assessment of Living Organ Donors: Clinical and Ethical Considerations  

Microsoft Academic Search

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, \\

Mary Ellen Olbrisch; Sharon M. Benedict

2001-01-01

287

The Fundamental Flaws of Immunoassays and Potential Solutions Using Tandem Mass Spectrometry  

PubMed Central

Immunoassays have made it possible to measure dozens of individual proteins and other analytes in human samples for help in establishing the diagnosis and prognosis of disease. In too many cases the results of those measurements are misleading and can lead to unnecessary treatment or missed opportunities for therapeutic interventions. These cases stem from problems inherent to immunoassays performed with human samples, which include a lack of concordance across platforms, autoantibodies, anti-reagent antibodies, and the high-dose hook effect. Tandem mass spectrometry may represent a detection method capable of alleviating many of the flaws inherent to immunoassays. We review our understanding of the problems associated with immunoassays on human specimens and describe methodologies using tandem mass spectrometry that could solve some of those problems. We also provide a critical discussion of the potential pitfalls of novel mass spectrometric approaches in the clinical laboratory.

Hoofnagle, Andrew N.; Wener, Mark H.

2009-01-01

288

Serologic Test-Systems Development: Immunoassays for Antibiotics. Progress Report, May 16, 1980-September 30, 1981.  

National Technical Information Service (NTIS)

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 Agri...

R. Brake U. Hollstein K. Hindman

1983-01-01

289

Enzyme-Linked Immunoassays for the Detection of Microbial Antigens and Their Antibodies.  

National Technical Information Service (NTIS)

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...

J. E. Herrmann

1986-01-01

290

Suitability of chemiluminescent enzyme immunoassay for the measurement of blood tacrolimus concentrations in rheumatoid arthritis  

Microsoft Academic Search

ObjectivesThe aim of this study was to evaluate the suitability of chemiluminescent enzyme immunoassay (CLIA) for the monitoring of whole-blood tacrolimus concentrations in rheumatoid arthritis (RA) patients.

Kumi Hirano; Shuji Maruyama; Yasuaki Mino; Takafumi Naito; Junichi Kawakami

2011-01-01

291

Line Blot and Western Blot Immunoassays for Diagnosis of Mediterranean Spotted Fever.  

National Technical Information Service (NTIS)

The line blot, a new immunoassay in which antigens are placed on nitrocellulose as narrow lines, was evaluated for its sensitivity and specificity relative to the microimmunofluorescence assay for the diagnosis of Mediterranean spotted fever (MSF). The li...

D. Raoult G. A. Dasch

1989-01-01

292

42 CFR 35.64 - Donors.  

Code of Federal Regulations, 2012 CFR

...Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICAL CARE AND EXAMINATIONS HOSPITAL AND STATION MANAGEMENT Contributions for the Benefit of Patients § 35.64 Donors. Authorized contributions may be accepted from...

2012-10-01

293

A Time for Flexible Donor Agreements.  

ERIC Educational Resources Information Center

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)

Fischer, Gerald B.

2003-01-01

294

21 CFR 610.41 - Donor deferral.  

Code of Federal Regulations, 2013 CFR

... (a) You, an establishment that collects human blood or blood components, must defer donors testing reactive...for syphilis under § 610.40(i), from future donations of human blood and blood components, except: (1)...

2014-04-01

295

Donor Immune Cells Attack Metastatic Breast Cancer  

Cancer.gov

In patients with metastatic breast cancer, immune cells from a genetically matched donor can attack and shrink tumors, researchers from the National Cancer Institute (NCI) announced today at the Annual Meeting of the American Society of Clinical Oncology in Chicago.

296

Improving Donor Intervention in Rural Financial Markets.  

National Technical Information Service (NTIS)

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...

J. D. Von Pischke

1981-01-01

297

Who Can Be an Organ Donor?  

MedlinePLUS

... yours alone. No one should pressure you into donating an organ. If you want to be an organ donor, ... your questions. 5. Can I get paid for donating an organ? No, it is against the law. You do ...

298

Residues determination of carbofuran in vegetables based on sensitive time-resolved fluorescence immunoassay  

Microsoft Academic Search

Using direct competitive time-resolved fluorescence immunoassay (TRFIA), a rapid, highly selective and sensitive method was developed for the determination of carbofuran residues in lettuce and carrot. The method was based on a direct competitive immunoassay using europium-labelled anti-carbofuran monoclonal antibody and carbofuran-ovalbumin as coated antigen. The sensitivity, estimated as the I50 value, was 34.54 ng\\/mL, with a detection limit (I10)

Wenjun Gui; Maojun Jin; Lifeng Sun; Yirong Guo; Guonian Zhu

2009-01-01

299

Investigation of several parameters influencing signal generation in flow-through membrane-based enzyme immunoassay  

Microsoft Academic Search

Rapid-response analytical tests that can be performed at the point of sampling are based on a visual detection system. The\\u000a influence of different factors on the signal generation in a membrane-based enzyme immunoassay was investigated. The research\\u000a was applied to a flow-through immunoassay for the detection of ochratoxin A (OTA). This assay format is a very convenient,\\u000a simple and fast

Anna Yu. Kolosova; Sarah De Saeger; Sergei A. Eremin; Carlos Van Peteghem

2007-01-01

300

Successively amplified electrochemical immunoassay based on biocatalytic deposition of silver nanoparticles and silver enhancement  

Microsoft Academic Search

A successively signal-amplified electrochemical immunoassay has been reported on the basis of the biocatalytic deposition of silver nanoparticles with their subsequent enlargement by nanoparticle-promoted catalytic precipitation of silver from the silver-enhancer solution. The immunoassay was carried out based on a heterogeneous sandwich procedure using polystyrene microwells to immobilize antibody. After all the processes comprising the formation of immunocomplex, biocatalytic deposition

Zhao-Peng Chen; Zhao-Feng Peng; Yan Luo; Bo Qu; Jian-Hui Jiang; Xiao-Bing Zhang; Guo-Li Shen; Ru-Qin Yu

2007-01-01

301

Analytical Performance and Clinical Utility of a Sensitive Immunoassay for Determination of Human Cardiac Troponin I  

Microsoft Academic Search

Objectives: To determine the serum and plasma level of human cardiac troponin I (cTnI) resulting from myocardial damage, we have developed a sensitive and specific one-step enzyme immunoassay to measure cardiac troponin I.Design and Methods: The COBAS® cTnI assay is a semi-automated one-step solid phase immunoassay compatible with the COBAS® Core. The assay is performed in a sandwich type format

Eric Davies; Yehia Gawad; Miyoko Takahashi; Quinwei Shi; Philip Lam; Garth Styba; Arthur Lau; Christopher Heeschen; Magdalena Usategui; George Jackowski

1997-01-01

302

Superfund innovative technology evaluation (site) program evaluation report for antox BTX water screen (BTX immunoassay)  

Microsoft Academic Search

The results of a demonstration of a portable immunoassay for the detection of benzene, toluene, and xylene(s) (BTX) are described in the report. Seventy-nine field samples were obtained from monitoring wells at several sites with gasoline contaminated ground water. Sample splits were analyzed on-site by the BTX immunoassay and in the laboratory by gas chromatography (GC) using EPA Method 8020.

R. W. Gerlach; R. J. White; N. F. OLeary; J. M. Van Emon

1993-01-01

303

Enhanced solid-phase immunoassay using gold nanoshells: effect of nanoparticle optical properties  

Microsoft Academic Search

Plasmon-resonant nanoparticle-labeled immunoassays provide a simple, low-cost and effective way of detecting target molecules in solutions. The optical mechanisms behind their efficiency, however, have not been addressed until now. We present the first theoretical description of nanoparticle-labeled dot immunoassay and its experimental verification with functionalized 15 nm colloidal gold nanospheres and silica\\/gold nanoshells (GNs). Three types of GNs, with silica

Boris Khlebtsov; Nikolai Khlebtsov

2008-01-01

304

Influence of hydrophobic and hydrophilic spacer-containing enzyme conjugates on functional parameters of steroid immunoassay  

Microsoft Academic Search

Introduction of spacers in coating steroid antigen or enzyme conjugates or immunogen is known to exert an influence on the sensitivity of steroid enzyme immunoassays. We have introduced hydrophobic and hydrophilic spacers between enzyme and steroid moieties and studied their effects on functional parameters of enzyme immunoassays, using cortisol as a model steroid. Cortisol-3-O-carboxymethyloxime–bovine serum albumin (F-3-O-CMO-BSA) was used as

Seema Nara; Vinay Tripathi; Shail K. Chaube; Kiran Rangari; Harpal Singh; Kiran P. Kariya; Tulsidas G. Shrivastav

2008-01-01

305

Enzyme conversion immunoassay for determining total homocysteine in plasma or serum  

Microsoft Academic Search

A rapid and precise immunoassay for quantification of total homocysteine in blood samples is presented. The method avoids the use of radioisotopes and chromato- graphic separations and relies on enzymatic conversion of homocysteine to S-adenosyl-L-homocysteine, fol- lowed by quantification of S-adenosyl-L-homocysteine by an enzyme-linked immunoassay in microtiter format. The within- and between-assay imprecision is <6% and 8%, respectively, and results

Frank Frantzen; Arne Ludvig Faaren; Ingrid Alfheim; Arne Kristian Nordhei

306

A novel immunoassay based on the dissociation of immunocomplex and fluorescence quenching by gold nanoparticles  

Microsoft Academic Search

This study reports a novel, simple and sensitive immunoassay using fluorescence quenching caused by gold nanoparticles coated with antibody. The method is based on a non-competitive heterogeneous immunoassay of human IgG conducted by the typical procedure of sandwich immunocomplex formation. Goat anti-human IgG was first adsorbed on polystyrene microwells, and human IgG analyte was captured by the primary antibody and

Zhaofeng Peng; Zhaopeng Chen; Jianhui Jiang; Xiaobing Zhang; Guoli Shen; Ruqin Yu

2007-01-01

307

Utilization of expanded criteria donors in liver transplantation.  

PubMed

Improvements in surgical techniques, immunosuppression, and post-transplantation patient care have led to the optimization of liver transplantation outcomes. However, the waiting list for liver transplantation is increasing at a greater pace. The large gap between the growing pool of patients waiting for liver transplantation and the scarcity of donor organs has fueled efforts to maximize existing donors and identify new sources. This article will be focused on the current state of liver transplantation using grafts from extended criteria donors (elderly donors, steatotic donors, donors with malignancies, donors with viral hepatitis) and from donation after cardiac death (DCD), as well as the use of partial grafts (split grafts and living-donor liver transplantation) and other suboptimal donors (donors with hypernatremia, infections, hypotension and inotropic support). Overall, broadened criteria for acceptable donor livers appear to lessen graft survival rates somewhat compared with rates for standard criteria organs. PMID:25013654

Saidi, Reza F

2013-01-01

308

Ethical issues in living donor liver transplantation  

Microsoft Academic Search

The cadaveric organ shortage and the high mortality rate while patients wait for an organ have driven the medical community\\u000a to develop alternative strategies for treating patients with end-stage liver disease. Adult living donor liver transplantation\\u000a (ALDT) has evolved in response to the cadaveric organ shortage. Although there are benefits for recipients of ALDT, donors\\u000a may incur substantial risk, including

Mark W. Russo; Robert S. Brown

2003-01-01

309

Organ Transplants from Living Donors - Halachic Aspects*  

PubMed Central

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.

Halperin, Mordechai

2011-01-01

310

Organ transplants from living donors - halachic aspects.  

PubMed

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

Halperin, Mordechai

2011-04-01

311

First donor stabilized-phosphenium rhodium complexes  

Microsoft Academic Search

The coordination properties of a donor stabilized-phosphenium adduct have been examined in rhodium chemistry. The preparation as well as the characterization of the first examples of donor stabilized-phosphenium rhodium(I) complexes is reported in this paper. Indeed, mono- and di-cationic rhodium complexes were obtained in quantitative yield by the direct addition of this imidazolium P(III)-ligand to [RhCl(1,5-COD)]2 in CH2Cl2 solution with

Jacques Andrieu; Michèle Azouri; Philippe Richard

2008-01-01

312

Single-site retroperitoneoscopic donor nephrectomy.  

PubMed

We have performed retroperitoneoscopic nephrectomy for living kidney donor surgery since 2000. Recently, we introduced single-site retroperitoneoscopic donor nephrectomy (RDN) as a less invasive donor surgery. The procedure was performed in 7 donors (5 women and 2 men) by a single surgeon. The mean age and body mass index of the donors were 62.6 years (range, 53-74 years) and 24.3 kg/m(2) (range, 22.3-29.0 kg/m(2)), respectively. Left-sided nephrectomy was performed in all the donors. The donors were positioned in the right lateral position, and a 7-cm-long incision was made in the left flank. The incision was extended to the retroperitoneal space using the muscle-splitting technique. The retroperitoneal space was then expanded using an inflation balloon. A GelPOINT Advanced Access Platform (Applied Medical, Rancho Santa Margarita, Calif, United States) was placed in the incision. The subsequent technique and equipment were the same as those used in conventional 3-port RDN. The renal artery and vein were dissected using a vascular stapler, and the kidney graft was directly extracted through the incision. The mean operative time was 197 ± 28 minutes, warm ischemic time was 4.1 ± 1.2 minutes, and blood loss was 75 ± 113 mL. No statistical differences were found between the present method and conventional 3-port RDN. Intraoperative and postoperative complications were not observed in any of the donors. Graft function after transplantation was good, and delayed graft function was not observed in any of the recipients. This technique can be easily introduced in the clinical setting by surgeons experienced in RDN. PMID:24655953

Maruyama, M; Akutsu, N; Ohtsuki, K; Aoyama, H; Matsumoto, I; Hasegawa, M; Saigo, K; Asano, T

2014-03-01

313

Effect of Electron Donor on PE Polymerization  

Microsoft Academic Search

Ziegler-Natta catalyst was prepared from colloidal MgCl2 (from reaction between magnesium ethyl carbonate and aluminium sesquichloride, Al2Et3Cl3) followed by contact with TiCl4. Al\\/Mg and Ti\\/Mg molar ratios were studied as parameters affecting the catalyst synthesis. Catalytic performance and effect of electron donor on ethylene polymerization were investigated. Results showed that addition of electron donor (ethyl benzoate) increased activity balance when

Roman HELMUTH STRAUSS

314

Catch and measure-mass spectrometry-based immunoassays in biomarker research.  

PubMed

Mass spectrometry-based (MS) methods are effective tools for discovering protein biomarker candidates that can differentiate between physiological and pathophysiological states. Promising candidates are validated in studies comprising large patient cohorts. Here, targeted protein analytics are used to increase sample throughput. Methods involving antibodies, such as sandwich immunoassays or Western blots, are commonly applied at this stage. Highly-specific and sensitive mass spectrometry-based immunoassays that have been established in recent years offer a suitable alternative to sandwich immunoassays for quantifying proteins. Mass Spectrometric ImmunoAssays (MSIA) and Stable Isotope Standards and Capture by Anti-Peptide Antibodies (SISCAPA/iMALDI) are two prominent types of MS-based immunoassays in which the capture is done either at the protein or the peptide level. We present an overview of these emerging types of immunoassays and discuss their suitability for the discovery and validation of protein biomarkers. This article is part of a Special Issue entitled: Biomarkers: A Proteomic Challenge. PMID:24060810

Weiß, Frederik; van den Berg, Bart H J; Planatscher, Hannes; Pynn, Christopher J; Joos, Thomas O; Poetz, Oliver

2014-05-01

315

Older patients/older donors: choosing wisely.  

PubMed

Two lingering problems regarding transplantation in older adults have been how to select patients appropriately and whether to use older sibling donors. Allogeneic hematopoietic cell transplantation (HCT) of older patients may result in long-term survival due to GVL, but the data remain observational and mostly restricted to those 50 to 69 years of age. Patients with excellent performance status and low comorbidity have the best long-term survival after HCT. Novel measures of health status such as self-report or performance-based functional measures allow "staging the age" and may inform candidacy for less robust patients. Older matched sibling donors should be preferred over matched unrelated donors (MUDs) because outcomes are equivalent to superior for matched sibling donors compared with MUD. However, MUDs also achieve acceptable outcomes and long-term disease control. An alternative donor can be considered based on institutional protocols and expertise. Very limited information is available in patients or related donors 70 years of age and older. Future efforts to more completely characterize patient health status before transplantation will allow better application of HCT in older adults. PMID:24319165

Artz, Andrew S

2013-01-01

316

Systemic Heparinisation in Laparoscopic Live Donor Nephrectomy  

PubMed Central

Introduction. Systemic heparinisation is advocated during laparoscopic live donor nephrectomy (LDN) as a preventative measure against renal vascular thrombosis during the warm ischaemic interval. This study compares the outcome with and without the administration of systemic heparinisation. Methods. A retrospective analysis was performed on 186 consecutive LDN patients between April 2008 and November 2012. Systemic heparin (2000–3000?IU) was administered intravenously to donors (hep n = 109). From January 2010, heparin was not used systemically in this group of LDN (no hep n = 77). Outcome measures included donor and recipient complications, initial graft function, and 12 month graft survival. Results. The demographics of both heparinised and non-heparinised donors were similar. The warm ischaemic time (WIT) was comparable in both groups (WIT; hep 5 ± 3 versus no hep 5 ± 3 minutes; P = 1.000). There was no difference in complication rates, no episodes of graft thrombosis, and no incidences of primary nonfunction in either group. Delayed graft function occurred in 4/109 and 1/77 (3.6% versus 1.2%; P = 0.405) and there was no significant difference in graft survival (P = 0.650). Conclusion. Omitting systemic heparinisation during laparoscopic donor nephrectomy is a feasible and safe approach that does not compromise donor or recipient outcome.

Hosgood, Sarah A.; Nicholson, Michael L.

2013-01-01

317

Influence of kinship on donors' mental burden in living donor liver transplantation.  

PubMed

In the context of living donor liver transplantation (LDLT), German transplantation law stipulates that donor candidates should primarily be relatives of the recipients or persons with distinct and close relationships. In this study, we investigated the influence of the relationship between the donor and the recipient on the donor's emotional strain before transplantation. Donors were categorized according to the following subgroups: (1) parents donating for their children, (2) children donating for their parents, (3) siblings, (4) spouses, (5) other relatives, and (6) nonrelatives. The sample consisted of 168 donor candidates. Anxiety (F = 2.8, P = 0.02), depression (F = 2.6, P = 0.03), and emotional quality of life (F = 3.1, P = 0.01) differed significantly according to the relationship between the donor and the recipient. In comparison with healthy controls, parents donating for their children were significantly less stressed before LDLT and demonstrated fewer anxiety (P < 0.01) and depression symptoms (P < 0.05). Adult children donating for their parents demonstrated the highest mental burden and the lowest emotional quality of life. However, this was not due to the responsibility of these children for their own families because differences between donors with children and donors without children could not be ascertained. This group should be given special attention before LDLT and during follow-up visits, and psychological help should be provided when it is necessary. PMID:22829418

Erim, Yesim; Beckmann, Mingo; Kroencke, Sylvia; Sotiropoulos, Georgios C; Paul, Andreas; Senf, Wolfgang; Schulz, Karl-Heinz

2012-08-01

318

Laparoscopic donor distal pancreatectomy for living donor pancreas and pancreas-kidney transplantation.  

PubMed

With the proliferation and expanding applications of laparoscopic techniques, we determined the applicability of the laparoscopic approach to living pancreas donation. We performed the first laparoscopic donor distal pancreatectomy in 1999. We herein present our initial experience with five hand-assisted laparoscopic donor pancreatectomies. Three donors underwent distal pancreatectomy alone; two underwent a simultaneous left nephrectomy. The mean donor age was 48.4+/-8.7 years with a body mass index of 23.7 kg/m2. The donor and recipient survival rate was 100% at up to 3 years of follow-up. There were no episodes of pancreatitis, leaks, or pseudocysts. All donors returned to their preoperative state of health and to work. None of the donors have required oral anti-diabetic medications or insulin. We conclude that laparoscopic donor distal pancreatectomy is a safe and efficient procedure; hand-assisted laparoscopic distal pancreatectomy appears to be preferable, because of the added margin of safety from increased tactile feedback and ease of pancreatic dissection. The procedure can be accomplished with a single 6-cm periumbilical incision and only two 12-mm ports, resulting in excellent cosmesis and high donor satisfaction. PMID:15996246

Tan, Miguel; Kandaswamy, Raja; Sutherland, David E R; Gruessner, Rainer W G

2005-08-01

319

Characterization of long-term mixed donor-donor chimerism after double cord blood transplantation  

PubMed Central

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 donor–donor 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 donor–donor 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 donor–donor 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 donor–donor mixed chimerism.

Gertow, J; Berglund, S; Okas, M; Uzunel, M; Berg, L; Karre, K; Mattsson, J; Uhlin, M

2010-01-01

320

A novel organ donor facility: a decade of experience with liver donors.  

PubMed

Transplant surgeons have historically traveled to donor hospitals, performing complex, time-sensitive procedures with unfamiliar personnel. This often involves air travel, significant delays, and frequently occurs overnight.In 2001, we established the nation's first organ recovery center. The goal was to increase efficiency,reduce costs and reduce surgeon travel. Liver donors and recipients, donor costs, surgeon hours and travel time, from April 1,2001 through December 31,2011 were analyzed. Nine hundred and fifteen liver transplants performed at our center were analyzed based on procurement location (living donors and donation after cardiac death donors were excluded). In year 1, 36% (9/25) of donor procurements occurred at the organ procurement organization (OPO) facility, rising to 93%(56/60) in the last year of analysis. Travel time was reduced from 8 to 2.7 h (p<0.0001), with a reduction of surgeon fly outs by 93% (14/15) in 2011. Liver organ donor charges generated by the donor were reduced by37% overall for donors recovered at the OPO facility versus acute care hospital. Organs recovered in this novel facility resulted in significantly reduced surgeon hours, air travel and cost. This practice has major implications for cost containment and OPO national policy and could become the standard of care. PMID:24612713

Doyle, M B M; Vachharajani, N; Wellen, J R; Lowell, J A; Shenoy, S; Ridolfi, G; Jendrisak, M D; Coleman, J; Maher, M; Brockmeier, D; Kappel, D; Chapman, W C

2014-03-01

321

Selecting suitable solid organ transplant donors: Reducing the risk of donor-transmitted infections  

PubMed Central

Selection of the appropriate donor is essential to a successful allograft recipient outcome for solid organ transplantation. Multiple infectious diseases have been transmitted from the donor to the recipient via transplantation. Donor-transmitted infections cause increased morbidity and mortality to the recipient. In recent years, a series of high-profile transmissions of infections have occurred in organ recipients prompting increased attention on the process of improving the selection of an appropriate donor that balances the shortage of needed allografts with an approach that mitigates the risk of donor-transmitted infection to the recipient. Important advances focused on improving donor screening diagnostics, using previously excluded high-risk donors, and individualizing the selection of allografts to recipients based on their prior infection history are serving to increase the donor pool and improve outcomes after transplant. This article serves to review the relevant literature surrounding this topic and to provide a suggested approach to the selection of an appropriate solid organ transplant donor.

Jr, Christopher S Kovacs; Koval, Christine E; van Duin, David; de Morais, Amanda Guedes; Gonzalez, Blanca E; Avery, Robin K; Mawhorter, Steven D; Brizendine, Kyle D; Cober, Eric D; Miranda, Cyndee; Shrestha, Rabin K; Teixeira, Lucileia; Mossad, Sherif B

2014-01-01

322

Expanding the live kidney donor pool: ethical considerations regarding altruistic donors, paired and pooled programs.  

PubMed

In renal transplant, there is a well-known deficiency in organ supply relative to demand. Live donation provides superior results when compared with deceased donation including a better rate of graft success and fewer immunologic complications. This deficiency in organs leads to significant morbidity and mortality rates. Alternative avenues have been extensively explored that may expand the live donor pool. They include altruistic donation as well as paired and pooled exchange programs. Altruistic donation is a truly selfless act from a donor unknown to the recipient. Kidney paired donation involves 2 incompatible donor-recipient pairs swapping donors to produce compatibility. Pooled donation involves at least 2 pairs, and can take the form of domino chains in which altruistic input sets up a chain of transplants, in which each recipient's incompatible donor makes a donation for the next recipient. Despite application of these various methods, there lie extensive ethical issues surrounding them. Misconceptions frequently occur; for instance, the perceived benefit that donating an organ to a loved one is greater for a related donor than for an altruistic one. Additionally, it is frequently believed that immunologic incompatibility offers coerced donors liberation from surgery, and that overcoming these barriers by introducing exchange programs provides vulnerable donors less protection. This article explores these and other complex ethical issues surrounding the various methods of expanding the donor pool. The authors offer opinions that challenge the ethical issues and attempt to overcome those views that hinder progress in the field. PMID:21649566

Patel, Shaneel Rajendra; Chadha, Priyanka; Papalois, Vassilios

2011-06-01

323

Explaining differences between hospitals in number of organ donors  

Microsoft Academic Search

The shortage of donor organs calls for a careful examination of all improvement options. In this study, 80 Dutch hospitals were compared. They provided 868 donors in a 5-year period, constituting 91% of all donors in that period in The Netherlands. Multilevel regression analysis was used to explain the differences between hospitals. Potential explanatory variables were hospital-specific mortality statistics, donor

R. D. Friele; R. Coppen; R. L. Marquet; J. K. M. Gevers

2006-01-01

324

Donor type semiconductor at low temperature as maser active medium  

Microsoft Academic Search

In some semiconductors donor impurity atoms can attract additional electrons, forming negative donor impurity ions. Thus we have 3 energy levels for electrons: zero energy levels at the bottom of the conductivity band, negative energy levels of the bounded electrons of the negative donor impurity ions, and deeper negative energy levels of the outer electrons of the neutral donor impurity

Yuri Kornyushin; Chalet Shalva

2007-01-01

325

Donor safety and remnant liver volume in living donor liver transplantation  

PubMed Central

AIM: To evaluate the relationship between donor safety and remnant liver volume in right lobe living donor liver transplantation (LDLT). METHODS: From July 2001 to January 2009, our liver transplant centers carried out 197 LDLTs. The clinical data from 151 cases of adult right lobe living donors (not including the middle hepatic vein) were analyzed. The conditions of the three groups of donors were well matched in terms of the studied parameters. The donors’ preoperative data, intraoperative and postoperative data were calculated for the three groups: Group 1 remnant liver volume (RLV) < 35%, group 2 RLV 36%-40%, and group 3 RLV > 40%. Comparisons included the different remnant liver volumes on postoperative liver function recovery and the impact of systemic conditions. Correlations between remnant liver volume and post-operative complications were also analyzed. RESULTS: The donors’ anthroposomatology data, operation time, and preoperative donor blood test indicators were calculated for the three groups. No significant differences were observed between the donors’ gender, age, height, weight, and operation time. According to the Chengdu standard liver volume formula, the total liver volume of group 1 was 1072.88 ± 131.06 mL, group 2 was 1043.84 ± 97.11 mL, and group 3 was 1065.33 ± 136.02 mL. The three groups showed no statistically significant differences. When the volume of the remnant liver was less than 35% of the total liver volume, the volume of the remnant had a significant effect on the recovery of liver function and intensive care unit time. In addition, the occurrence of complications was closely related to the remnant liver volume. When the volume of the remnant liver was more than 35% of the total liver volume, the remnant volume change had no significant effect on donor recovery. CONCLUSION: To ensure donor safety, the remnant liver volume should be greater than the standard liver volume (35%) in right lobe living donor liver transplantation.

Shi, Zheng-Rong; Yan, Lu-Nan; Du, Cheng-You

2012-01-01

326

Evaluation of the Medically Complex Living Kidney Donor  

PubMed Central

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.

Caliskan, Yasar; Yildiz, Alaattin

2012-01-01

327

Fear, fascination and the sperm donor as 'abjection' in interviews with heterosexual recipients of donor insemination.  

PubMed

The background to this article is the medical regulation of sperm donation in the UK and the recent policy change so that children born from sperm, eggs or embryos donated after April 2005 have the right to know their donor's identity. I draw upon data from interviews with ten women and seven joint interviews with couples who received donor insemination from an anonymous sperm donor and were the parents of donor insemination children. I explore the symbolic presence of the donor and his potential to disrupt social and physical boundaries using the theoretical conceptions of boundaries and pollution as articulated by Mary Douglas and Julia Kristeva. I present data to argue that the anonymous donor manifests in various figures; the shadowy and ambiguous figure of 'another man'; the intelligent medical student; the donor as a family man, with children of his own who wants to help infertile men father children. In addition participants perceive the donor's physical characteristics, but also see their husband's physical characteristics, in their children. In conclusion I argue that anonymisation preserves features of conventional family life, maintains the idea of exclusivity within the heterosexual relationship and affirms the legal father's insecurity about his infertility. PMID:19470135

Burr, Jennifer

2009-07-01

328

Molecular assembly of amino acid interlinked, topologically symmetric, ?-complementary donor-acceptor-donor triads  

PubMed Central

Summary Amino acid interlinked pyrene and naphthalenediimide (NDI) based novel donor–acceptor–donor (D-A-D) triads are designed to exploit their topological symmetry and complementary ?-character for facile charge-transfer complexation. Consequently, free-floating high-aspect-ratio supercoiled nanofibres and hierarchical helical bundles of triads are realized by modulating the chemical functionality of interlinking amino acids.

Avinash, M B; Sandeepa, K V

2013-01-01

329

Improvements in detection of antibody to hepatitis B core antigen by treating specimens with reducing agent in an automated microparticle enzyme immunoassay.  

PubMed Central

A fully automated microparticle enzyme immunoassay (EIA), IMx Core, was developed for the detection of antibody against hepatitis B core antigen (anti-HBc). IMx Core sensitivity was less than 0.5 Paul Ehrlich Institut units per ml and was greater than that of the commercial radioimmunoassay (RIA) or EIA, Corab and Corzyme, respectively. Specimens from blood donors and diagnostic and hospital patients, which included individuals with a variety of infectious and immune diseases, were tested in parallel by the IMx Core and EIA. Overall agreement of 99.1% (4,797 of 4,841) was obtained. Prevalence of anti-HBc tested by IMx Core ranged from 1.2% in volunteer blood donors to 9.1% in hospital laboratories. Discordant specimens reactive by IMx Core but negative by Corzyme or Corab resulted from the increased sensitivity of the IMx Core assay, since other hepatitis B markers were usually present. However, most discordant specimens were positive by the EIA or RIA but negative by IMx Core. No other hepatitis B markers could be detected in these discordants, and after addition of reducing agent, these specimens also became negative by EIA or RIA. In clinical trials, 30% (14 of 47) of volunteer blood donors and 8% (9 of 119) of hospital patients testing repeatedly reactive by the EIA had reduction-sensitive (unspecific) anti-HBc reactivity. The reducing agent, dithiothreitol, was added to each specimen automatically in the IMx assay to eliminate these unspecific reactions without significantly affecting anti-HBc reactivity resulting from hepatitis B virus infection as judged by the correlation with other hepatitis B markers.

Spronk, A M; Schmidt, L; Krenc, C; Pavlis-Jenkins, L; Brady, J; Taskar, S; Angus-Finn, L; Mimms, L

1991-01-01

330

The Effect of Donor Age on Corneal Transplantation Outcome: Results of the Cornea Donor Study  

PubMed Central

Objective To determine whether graft survival over a 5-year follow-up period using corneal tissue from donors older than 65 years of age is similar to graft survival using corneas from younger donors. Design Multi-center prospective, double-masked, controlled clinical trial Participants 1090 subjects undergoing corneal transplantation for a moderate risk condition (principally Fuchs’ dystrophy or pseudophakic corneal edema); 11 subjects with ineligible diagnoses were not included Methods 43 participating eye banks provided corneas from donors in the age range of 12 to 75 with endothelial cell densities of 2300 to 3300 cells/mm2, using a random approach without respect to recipient factors. The 105 participating surgeons at 80 sites were masked to information about the donor cornea including donor age. Surgery and post-operative care were performed according to the surgeons’ usual routines. Subjects were followed for five years. Main Outcome Measures Graft failure, defined as a regraft or a cloudy cornea that was sufficiently opaque as to compromise vision for a minimum of three consecutive months. Results The 5-year cumulative probability of graft survival was 86% in both the <66.0 donor age group and the ?66.0 donor age group (difference = 0%, upper limit of one-sided 95% confidence interval = 4%). In a statistical model with donor age as a continuous variable, there was not a significant relationship between donor age and outcome (P=0.11). Three graft failures were due to primary donor failure, 8 to uncorrectable refractive error, 48 to graft rejection, 46 to endothelial decompensation (23 of which had a prior, resolved episode of probable or definite graft rejection), and 30 to other causes. The distribution of the causes of graft failure did not differ between donor age groups. Conclusions Five-year graft survival for cornea transplants at moderate risk for failure is similar using corneas from donors ? 66.0 years and donors < 66.0 years. Surgeons and patients now have evidence that corneas comparable in quality to those used in this study from donors through age 75 years are suitable for transplantation.

2009-01-01

331

Towards a single P donor in Si  

NASA Astrophysics Data System (ADS)

Individual P donors in Si form the basis of several schemes for realizing solid-state qubits. Technologically, all such schemes rely on the precise positioning of P donors in the Si crystal and fabrication of local gates, only a few tens of nanometers wide. Towards this goal, we have demonstrated that the spatial resolution of STM-lithography allows precise positioning of donors on the sub-nm length scale and also fabrication of all-epitaxial, planar quantum dot (QD) architectures, with source, drain, and gate patterns of precisely defined dimensions. Here, we report the STM-lithography fabrication of an ultra-small QD consisting, in the extreme limit, of a single P donor. Transport spectroscopy of the QD-device at mK temperatures shows stable Coulomb oscillations with an addition energy (around zero gate bias) of 44±2 meV. This value corresponds to the difference in the binding energies of the 1-electron (D^0) and the 2 --electron (D^-) states of a P donor in Si. The first two D^0 excited states have also been identified.

Mahapatra, Suddhasatta; Wei, Tang; Ryu, Hoon; Klimeck, Gerhard; Simmons, Michelle

2010-03-01

332

Bioluminescent Enzyme Immunoassay for the Detection of Norovirus Capsid Antigen  

PubMed Central

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 105 to 106 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.

Ohiro, Yoshiyuki; Ito, Mitsuki; Makinodan, Mitsuru; Ohta, Tsubasa; Suzuki, Wataru; Takayasu, Susumu; Tsuge, Harufumi

2012-01-01

333

Designing novel nano-immunoassays: antibody orientation versus sensitivity  

NASA Astrophysics Data System (ADS)

There is a growing interest in the use of magnetic nanoparticles (MNPs) for their application in quantitative and highly sensitive biosensors. Their use as labels of biological recognition events and their detection by means of some magnetic method constitute a very promising strategy for quantitative high-sensitive lateral-flow assays. In this paper, we report the importance of nanoparticle functionalization for the improvement of sensitivity for a lateral-flow immunoassay. More precisely, we have found that immobilization of IgG anti-hCG through its polysaccharide moieties on MNPs allows more successful recognition of the hCG hormone. Although we have used the detection of hCG as a model in this work, the strategy of binding antibodies to MNPs through its sugar chains reported here is applicable to other antibodies. It has huge potential as it will be very useful for the development of quantitative and high-sensitive lateral-flow assays for its use on human and veterinary, medicine, food and beverage manufacturing, pharmaceutical, medical biologics and personal care product production, environmental remediation, etc.

Puertas, S.; Moros, M.; Fernández-Pacheco, R.; Ibarra, M. R.; Grazú, V.; de la Fuente, J. M.

2010-12-01

334

Early Detection of Cancer: Immunoassays for Plasma Tumor Markers  

PubMed Central

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.

Meany, Danni L.; Sokoll, Lori J.; Chan, Daniel W.

2009-01-01

335

Surface plasmon resonance-based immunoassay for human fetuin A.  

PubMed

This article describes a highly-sensitive surface plasmon resonance (SPR)-based immunoassay (IA) for human fetuin A (HFA), a specific biomarker for atherosclerosis and hepatocellular carcinoma. The assay is based on a novel immobilization procedure that simply involves the dilution of an anti-HFA capture antibody (Ab) in 1% (v/v) 3-aminopropyltriethoxysilane (APTES), followed by its dispensing on a KOH-treated gold (Au)-coated SPR chip and incubation for 30 min. The developed SPR IA detected 0.3-20 ng mL(-1) of HFA with a limit of detection and sensitivity of 0.7 ng mL(-1) and 1 ng mL(-1), respectively. The highly-simplified Ab immobilization procedure is also 5-fold more rapid than conventional procedures. It leads to the leach-proof binding of the capture Ab, which means that the developed SPR IA is highly cost-effective, as the Ab-bound SPR chip could be reused for many repeated HFA IAs after regeneration with 10 mM glycine-HCl, pH 2.0. The Ab-bound SPR chip, stored at 4 °C, lost only 18% of its original activity after 4 months. For the detection of HFA spiked in diluted human whole blood and plasma, the results obtained by the developed SPR IA agreed well with the commercial HFA sandwich ELISA. PMID:24652275

Vashist, S K; Schneider, E M; Luong, J H T

2014-05-01

336

Haptens and monoclonal antibodies for immunoassay of imidazolinone herbicides.  

PubMed

A set of haptens structurally resembling the herbicide imazethapyr (PURSUIT) was synthesized and used to derive monoclonal antibodies (MAbs) and direct and indirect competition enzyme immunoassays (EIAs) which could detect imazethapyr, imazaquin (SCEPTER), imazapic (CADRE), and imazamox (RAPTOR) in the 3-30 ng/mL (parts per billion) range, and imazapyr (ARSENAL) and imazamethabenz-methyl (ASSERT) in the 300-500 ppb range. Two MAbs, 3A2 and 3A5, had affinities of 10-75 nM for imazethapyr. MAbs 1A5, 1D2, and 3A5 were specific for the S isomers of the herbicides. Some MAbs were stable in solutions containing up to 15% methanol and 5% acetonitrile in indirect EIAs. Plates coated with hapten conjugates for indirect EIA could be stored frozen. Selectivity for the imidazolinones by some MAbs varied with different coating conjugates. These MAbs and haptens should prove useful in immunochemical analysis and residue recovery methods for imazethapyr and other imidazolinone herbicides. PMID:12033799

Chin, Tina E; Wong, Rosie B; Pont, Joseph L; Karu, Alexander E

2002-06-01

337

Enzyme immunoassay of thyroxin with a centrifugal analyzer  

SciTech Connect

We have applied a homogeneous enzyme immunoassay for determination of thyroxinin serum to the ''Cobas Bio'' centrifugal analyzer. To unbind thyroxin from its protein complex, serum is treated for 20 min with a solution of NaOH containing ''Lipex,'' an agent for sequestering free fatty acids. The immunoenzymic reaction is then automatically performed by the analyzer at 37/sup 0/C. To 20 ..mu..L of sample mixture is added 125 ..mu..L of reagent (thyroxin antibodies and NAD/sup +/) and this mixture is incubated for 10 s. Then 25 ..mu..L of start reagent (enzyme-thyroxin conjugate and malate substrate) is added and the change in absorbance is monitored at 340 nm. The standard curve is linear up to at least 200 ..mu..g of thyroxin per liter. Within-assay precision (CV) varied from 1.1 to 2.9%, between-assay precision from 3.1 to 7.8%. Analytical recovery of thyroxin was complete. The deviation of control samples from target values ranged from -2.1% to 7.0%. Interference by hemoglobin or bilirubin is negligible. Results compare favorably with those by radioimmunoassay.

Izquierdo, J.M.; Sotorrio, P.; Quiros, A.

1982-01-01

338

Lead analysis by anti-chelate fluorescence polarization immunoassay.  

PubMed

Lead concentrations were determined by a fluorescence polarization immunoassay (FPIA) method that uses polyclonal antibodies raised against the lead(II) chelate of ethylenediamine-N,N,N',N'-tetraacetic acid (EDTA). The technique is based on competition for a fixed concentration of antibody binding sites between Pb-EDTA, formed by treating the sample with excess EDTA, and a fixed concentration of a fluorescent analogue of the Pb-EDTA complex. The objective was to correlate results obtained by FPIA with those produced by conventional atomic spectroscopy analysis of soils, solid waste leachates (produced by the Toxicity Characteristic Leachate Procedure; TCLP), airborne dust, and drinking water. Linear regression analysis of FPIA results for 138 soil samples containing 0-3094 ppm Pb(II) by flame atomic absorption spectroscopy and 40 TCLP extracts containing 0-668 ppm Pb(II) by inductively coupled plasma atomic emission spectroscopy produced correlation coefficients (r2) of 0.96 and 0.93, respectively. Pilot studies of mineral acid extracts of airborne dust trapped on fiberglass filters and of two sources of drinking water demonstrated the feasibility of also measuring lead in these matrixes by FPIA. The limit of detection under conditions that minimized sample dilution was approximately 1 ppb, and cross reactivity with 15 nontarget metals was below 0.5% in all cases. The methods are simple to perform and are amenable to field testing and mobile laboratory use, allowing timely and cost-effective characterization of suspected sources of lead contamination. PMID:11917989

Johnson, David K; Combs, Sherry M; Parsen, John D; Jolley, Michael E

2002-03-01

339

Development of enzyme immunoassay for detection of DDT.  

PubMed

Dichlorodiphenyltrichloroethane (DDT) is one of the persistent organic pollutants (POPs) widely found in the environment and in the general population. In this study, a direct competitive enzyme immunoassay (EIA) has been developed for the quantitative analysis of DDT. To generate a specific polyclonal antibody for EIA, p, p'-DDT was conjugated to porcine thyroglobulin for rabbit immunization. At optimized EIA conditions, the standard curves ranged from 0.137 to 100 ng/mL with the quantification limit of 0.41 ng/mL. The coefficients of variation (CV%) were 5.42-10.53% for intra-assay and 6.04-7.26% for inter-assay. Cross-reactivities with DDT metabolites (DDTs, including o, p'-DDT, p, p'-DDD, o, p'-DDD, p, p'-DDE, o, p'-DDE, p, p'-dichlorobenzophenone (DCBP), o, p'-DCBP) were investigated. The polyclonal antibody showed relatively low and/or no cross-reactivity with these compounds, and the assay was seen to be highly selective for p, p'-DDT. Moreover, the DDTs could be ranked by their reactivity: DDT > DDD > DDE > DCBP. In addition, the characterization of the polyclonal antibody indicated that the antiserum possesses a high specificity for p, p'-isomers. The results indicated that the developed EIA using this antibody could be a convenient and supplemental analytical tool for monitoring DDT. PMID:18161572

Hirano, Masashi; Kitamura, Kazuyuki; Kato, Ikuo; Yanaihara, Chizuko; Iwamoto, Ken-ichi; Sekiyama, Makiko; Watanabe, Chiho; Nakamoto, Takashi; Miyamoto, Nobukazu; Onishi, Yuta; Arizono, Koji

2008-01-01

340

Comparison of different immunoassays for CA 19-9.  

PubMed

We compared six routinely employed immunoassay kits: Architect i2000 and AxSYM, Abbott Laboratories; Elecsys 2010, Roche Diagnostics; ELSA, CIS-BioInternational; Immulite 1, Diagnostic Products Corporation; and IRMA-mat, Byk-Sangtec Diagnostica. Using all analytical systems, we measured identical groups of clinical samples completed with selected control samples. The repeatability of measurements (coefficient of variation) ranged from 2.1% (Elecsys 2010) to 6.7% (ELSA). The parameters of Passing-Bablok regression show significant systematic differences among analytical systems. Data from a Bland-Altman diagram suggest that these differences project onto other, still more significant individual differences among individual samples. Though the cut-off values differ between various systems, no similar clinical efficacy appears to be attained. The behavior of individual systems is quite different for identical control materials and does not necessarily duplicate the calibration for biological samples. The results of determining CA 19-9 cannot be extrapolated from one analytical technique to another, even in cases where the same monoclonal antibody is used. Standardization of CA 19-9 measurement systems is necessary to allow use of the results for the purposes of evidence-based medicine. PMID:11798090

Stern, P; Friedecky, B; Bartos, V; Bezdickova, D; Vavrova, J; Uhrova, J; Rozprimova, L; Zima, T; Palicka, V

2001-12-01

341

Immunoassay for lead ions: analysis of spiked food samples.  

PubMed

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

2014-01-01

342

System and method for a parallel immunoassay system  

DOEpatents

A method and system for detecting a target antigen using massively parallel immunoassay technology. In this system, high affinity antibodies of the antigen are covalently linked to small beads or particles. The beads are exposed to a solution containing DNA-oligomer-mimics of the antigen. The mimics which are reactive with the covalently attached antibody or antibodies will bind to the appropriate antibody molecule on the bead. The particles or beads are then washed to remove any unbound DNA-oligomer-mimics and are then immobilized or trapped. The bead-antibody complexes are then exposed to a test solution which may contain the targeted antigens. If the antigen is present it will replace the mimic since it has a greater affinity for the respective antibody. The particles are then removed from the solution leaving a residual solution. This residual solution is applied a DNA chip containing many samples of complimentary DNA. If the DNA tag from a mimic binds with its complimentary DNA, it indicates the presence of the target antigen. A flourescent tag can be used to more easily identify the bound DNA tag.

Stevens, Fred J. (Naperville, IL)

2002-01-01

343

Preparation of horseradish peroxidase hydrazide and its use in immunoassay.  

PubMed

Preparation of horseradish peroxidase (HRP) hydrazide that is HRP linked to adipic acid dihydrazide (HRP-ADH) and its use in enzyme immunoassay (EIA) is described. In this new strategy, horseradish peroxidase was conjugated to adipic acid dihydrazide using a carbodiimide coupling method. The resulting HRP-ADH was then coupled to cortisol-21-hemisuccinate (Cortisol-21-HS) to prepare enzyme conjugate. The prepared cortisol-21-HS coupled ADH-HRP (Cortisol-21-HS-ADH-HRP) enzyme conjugate was used for the development of an enzyme linked immunosorbent assay (ELISA) for direct estimation of cortisol. To the cortisol antibody coated microtiter wells, standard or serum samples (50 microL), along with cortisol-21-HS-ADH-HRP enzyme conjugate (100 microL) were incubated for 1 h at 37 degrees C. Bound enzyme activity was measured by using tetramethyl benzidine/hydrogen peroxide (TMB/H2O2) as substrate. The sensitivity of the assay was 0.05 microg/dL and the analytical recovery ranged from 92.9 to 101.7%. PMID:12953974

Shrivastav, Tulsidas G

2003-01-01

344

Aqueous two-phase systems enable multiplexing of homogeneous immunoassays  

PubMed Central

Quantitative measurement of protein biomarkers is critical for biomarker validation and early disease detection. Current multiplex immunoassays are time consuming costly and can suffer from low accuracy. For example, multiplex ELISAs require multiple, tedious, washing and blocking steps. Moreover, they suffer from nonspecific antibody cross-reactions, leading to high background and false-positive signals. Here, we show that co-localizing antibody-bead pairs in an aqueous two-phase system (ATPS) enables multiplexing of sensitive, no-wash, homogeneous assays, while preventing nonspecific antibody cross-reactions. Our cross-reaction-free, multiplex assay can simultaneously detect picomolar concentrations of four protein biomarkers ((C-X-C motif) ligand 10 (CXCL10), CXCL9, interleukin (IL)-8 and IL-6) in cell supernatants using a single assay well. The potential clinical utility of the assay is demonstrated by detecting diagnostic biomarkers (CXCL10 and CXCL9) in plasma from 88 patients at the onset of the clinical symptoms of chronic graft-versus-host disease (GVHD).

Simon, Arlyne B.; Frampton, John P.; Huang, Nien-Tsu; Kurabayashi, Katsuo; Paczesny, Sophie; Takayama, Shuichi

2014-01-01

345

A Portable Analyzer for Pouch-Actuated, Immunoassay Cassettes.  

PubMed

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 the pouches in the cassette, which facilitates the pumping and mixing of sample and reagents, and to close diaphragm-based valves for flow control. The same types of actuators are used to compress pouches and actuate valves. The analyzer also houses a compact OEM scanner/reader to excite fluorescence and detect emission from labels. The analyzer is hydraulically isolated from the cassette, reducing the possibility of cross-contamination. The analyzer facilitates programmable, automated execution of a sequence of operations such as pumping and valving in a timely fashion, reducing the level of expertise required from the operator and the possibility for errors. The analyzer's design is modular and expandable to accommodate cassettes of various complexities and additional functionalities. In this paper, the utility of the analyzer has been demonstrated with the execution of a simple, consecutive, lateral flow assay of a model biological system and the test results were detected with up converting phosphor labels that are excited at infrared frequencies and emit in the visible spectrum. PMID:22125359

Qiu, Xianbo; Liu, Changchun; Mauk, Michael G; Hart, Robert W; Chen, Dafeng; Qiu, Jing; Kientz, Terry; Fiene, Jonathan; Bau, Haim H

2011-12-15

346

Specific immunoassays for placental alkaline phosphatase as a tumor marker.  

PubMed

Human placental (hPLAP) and germ cell (PLAP-like) alkaline phosphatases are polymorphic and heat-stable enzymes. This study was designed to develop specific immunoassays for quantifying hPLAP and PLAP-like enzyme activity (EA) in sera of cancer patients, pregnant women, or smokers. Polyclonal sheep anti-hPLAP antibodies were purified by affinity chromatography with whole hPLAP protein (ICA-PLAP assay) or a synthetic peptide (aa 57-71) of hPLAP (ICA-PEP assay); the working range was 0.1-11 U/L and cutoff value was 0.2 U/L EA for nonsmokers. The intra- and interassay coefficients of variation were 3.7%-6.5% (ICA-PLAP assay) and 9.0%-9.9% (ICA-PEP assay). An insignificant cross-reactivity was noted for high levels of unheated intestinal alkaline phosphatase in ICA-PEP assay. A positive correlation between the regression of tumor size and EA was noted in a child with embryonal carcinoma. It can be concluded that ICA-PEP assay is more specific than ICA-PLAP, which is still useful to detect other PLAP/PLAP-like phenotypes. PMID:17489017

Stinghen, Sérvio T; Moura, Juliana F; Zancanella, Patrícia; Rodrigues, Giovanna A; Pianovski, Mara A; Lalli, Enzo; Arnold, Dodie L; Minozzo, João C; Callefe, Luis G; Ribeiro, Raul C; Figueiredo, Bonald C

2006-01-01

347

The microassay on a card: A rugged, portable immunoassay  

NASA Technical Reports Server (NTRS)

The Microassay on a Card (MAC) is a portable, hand-held, non-instrumental immunoassay that can test for the presence of a wide variety of substances in the environment. The MAC is a simple device to use. A drop of test solution is placed on one side of the card and within five minutes a color is developed on the other side in proportion to the amount of substance in the test solution, with sensitivity approaching 10 ng/ml. The MAC is self-contained and self-timed; no reagents or timing is necessary. The MAC may be configured with multiple wells to provide simultaneous testing for multiple species. As envisioned, the MAC will be employed first as an on-site screen for drugs of abuse in urine or saliva. If the MAC can be used as a screen of saliva for drugs of abuse, it could be applied to driving while intoxicated, use of drugs on the job, or testing of the identity of seized materials. With appropriate modifications, the MAC also could be used to test for environmental toxins or pollutants.

Kidwell, David

1991-01-01

348

Quantitative analysis of plasma interleiukin-6 by immunoassay on microchip  

NASA Astrophysics Data System (ADS)

Sandwich enzyme-linked immunoassay (ELISA) is one of the most frequently employed assays for clinical diagnosis, since this enables the investigator to identify specific protein biomarkers. However, the conventional assay using a 96-well microtitration plate is time- and sample-consuming, and therefore is not suitable for rapid diagnosis. To overcome these drawbacks, we performed a sandwich ELISA on a microchip. We employed the piezoelectric inkjet printing for deposition and fixation of 1st antibody on the microchannnel surface (300 ?m width and 100 ?m depth). Model analyte was interleukin-6 (IL-6) which was one of the inflammatory cytokine. After blocking the microchannel, antigen, biotin-labeled 2nd antibody, and avidin-labeled peroxidase were infused into the microchannel and incubated for 20 min, 10 min, and 5 min, respectively. This assay could detect 2 pg/ml and quantitatively measure the range of 0-32 pg/ml. Liner regression analysis of plasma IL-6 concentration obtained by microchip and conventional methods exhibited a significant relationship (R2 = 0.9964). This assay reduced the time for the antigen-antibody reaction to 1/6, and the consumption of samples and reagents to 1/50 compared with the conventional method. This assay enables us to determine plasma IL-6 with accuracy, high sensitivity, time saving ability, and low consumption of sample and reagents, and thus will be applicable to clinic diagnosis.

Abe, K.; Hashimoto, Y.; Yatsushiro, S.; Yamamura, S.; Tanaka, M.; Ooie, T.; Baba, Y.; Kataoka, M.

2012-03-01

349

Sensitive chemiluminescence immunoassay by capillary electrophoresis with gold nanoparticles.  

PubMed

This technical note describes a new chemiluminescence immunoassay hyphenated to capillary electrophoresis (CE-based CL-IA) with gold nanoparticles (AuNPs) technique for biological molecules determination. AuNPs were used as a protein label reagent in the light of its excellent catalytic effect to the CL reaction of luminol and hydrogen peroxide. AuNPs conjugate with antibody (Ab) to form tagged antibody (Ab*), and then Ab* link to antigen (Ag) to produce an Ab*-Ag complex by a noncompetitive immunoreaction. The mixture of the excess Ab* and the Ab*-Ag complex was baseline separated and detected within 5 min under the optimized conditions. This new protocol was evaluated with human immunoglobulin G (IgG) as the target molecule. The calibration curve of IgG was in the range of 0.008-5 ?g/mL with a correlation coefficient of 0.995. The detection limit (S/N = 3) of IgG was 1.14 × 10(-3) ?g/mL (7.1 pmol/L, 0.39 amol). The proposed AuNPs enhanced CE-based CL-IA method was successfully applied for the quantification of IgG in human sera from patients. It proves that the present method could be developed into a new and sensitive biochemical analysis technique. PMID:21218847

Liu, Yan-ming; Mei, Lin; Liu, Li-juan; Peng, Long-fei; Chen, Yong-hong; Ren, Shu-wei

2011-02-01

350

Analytic performance of two automated nonpretreatment digoxin immunoassays.  

PubMed

The analytic performance of two automated nonpretreatment digoxin methods, AxSYM Digoxin II and Vitros digoxin immunoassays, was assessed. Both assays had analytic sensitivities of less than 0.2 microg/L, were linear from digoxin concentrations of 0.5 to 4.0 microg/L, and showed acceptable precision, with a maximum total coefficient of variation (CV) of 8.9% and 6.4% for the AxSYM and Vitros, respectively. Comparison of the two methods using samples from patients receiving digoxin gave the following relationship: Vitros = 0.91 x AxSYM + 0.23 (r = 0.97, Sy,x = 0.12). Digoxinlike immunoreactive factor (DLIF) crossreactivity was examined in specimens from patients who had hepatic disease, renal insufficiency, had undergone cardiac surgery, and in neonatal cord blood samples. Minimal crossreactivity was observed for most samples and the average crossreactivity for each group of samples was comparable for the two methods. The recovery of digoxin added to samples from each group of DLIF was similar, except for that from cord blood samples, for which recovery was significantly lower with the AxSYM method. Titration of a digoxin-spiked serum pool with digoxin-immune Fab showed a similar decrease in the measured digoxin concentration for both methods. Overall, the analytic performance characteristics of these two methods were comparable. PMID:10051065

De, B K; Booth, D D; Magee, P J; Moore, M L; Preuss, T M; Rose, T A; Roberts, W L

1999-02-01

351

A Portable Analyzer for Pouch-Actuated, Immunoassay Cassettes  

PubMed Central

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 the pouches in the cassette, which facilitates the pumping and mixing of sample and reagents, and to close diaphragm-based valves for flow control. The same types of actuators are used to compress pouches and actuate valves. The analyzer also houses a compact OEM scanner/reader to excite fluorescence and detect emission from labels. The analyzer is hydraulically isolated from the cassette, reducing the possibility of cross-contamination. The analyzer facilitates programmable, automated execution of a sequence of operations such as pumping and valving in a timely fashion, reducing the level of expertise required from the operator and the possibility for errors. The analyzer’s design is modular and expandable to accommodate cassettes of various complexities and additional functionalities. In this paper, the utility of the analyzer has been demonstrated with the execution of a simple, consecutive, lateral flow assay of a model biological system and the test results were detected with up converting phosphor labels that are excited at infrared frequencies and emit in the visible spectrum.

Qiu, Xianbo; Liu, Changchun; Mauk, Michael G.; Hart, Robert W.; Chen, Dafeng; Qiu, Jing; Kientz, Terry; Fiene, Jonathan; Bau, Haim H.

2011-01-01

352

Microfluidic immunoassays as rapid saliva-based clinical diagnostics  

PubMed Central

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.

2007-01-01

353

Sensitive giant magnetoresistive-based immunoassay for multiplex mycotoxin detection.  

PubMed

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 microm x 90 microm, arranged in an 8 x 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 B(1), zearalenone and HT-2) and show that a detection limit of 50 pg/mL can be achieved. PMID:20047828

Mak, Andy C; Osterfeld, Sebastian J; Yu, Heng; Wang, Shan X; Davis, Ronald W; Jejelowo, Olufisayo A; Pourmand, Nader

2010-03-15

354

Quantitative multianalyte microarray immunoassay utilizing upconverting phosphor technology.  

PubMed

A quantitative multianalyte immunoassay utilizing luminescent upconverting single-crystal nanoparticles as reporters on an antibody array-in-well platform was demonstrated. Upconverting nanoparticles are inorganic rare earth doped materials that have the unique feature of converting low energy infrared radiation into higher energy visible light. Autofluorescence, commonly limiting the sensitivity of fluorescence-based assays, can be completely eliminated with photon upconversion technology because the phenomenon does not occur in biological materials. Biotinylated antibodies for three analytes (prostate specific antigen, thyroid stimulating hormone, and luteinizing hormone) were printed in an array format onto the bottom of streptavidin-coated microtiter wells. Analyte dilutions were added to the wells, and the analytes were detected with antibody-coated upconverting nanoparticles. Binding of the upconverting nanoparticles was imaged with an anti-Stokes photoluminescence microwell imager, and the standard curves for each analyte were quantified from the selected spot areas of the images. Single analyte and reference assays were also carried out to compare with the results of the multianalyte assay. Multiplexing did not have an effect on the assay performance. This study demonstrates the feasibility of upconverting single-crystal nanoparticles for imaging-based detection of quantitative multianalyte assays. PMID:22985020

Päkkilä, Henna; Ylihärsilä, Minna; Lahtinen, Satu; Hattara, Liisa; Salminen, Niina; Arppe, Riikka; Lastusaari, Mika; Saviranta, Petri; Soukka, Tero

2012-10-16

355

Blood Donor Deferrals by Expert System  

PubMed Central

Blood collection facilities have recently witnessed a substantial increase in the number of different tests used to detect infectious disease in donor populations. These facilities are also experiencing an increasingly stringent regulatory effort on the part of the Food and Drug Administration to determine the validity of the software used to handle this information. This report describes a precedence-based inference program (PRELOG) and a modular expert system used to determine a donor's suitability for continued donations (donor deferrals), and whether the donated unit can be released for transfusion. PRELOG accepts ternary logic input, in which test results are allowed to be positive, negative, or undetermined; and allows one to assign precedence values to the logic rules. These features enable programs to be written in a shorter, more error-resistant manner. A comparison between PRELOG and PROLOG is included, and the utility of this approach in producing and validating blood bank software is discussed.

Sorace, James M.; Berman, Jules J.; Brown, Lawrence A.; Moore, G. William

1990-01-01

356

Cross-reactivity of steroid hormone immunoassays: clinical significance and two-dimensional molecular similarity prediction  

PubMed Central

Background Immunoassays are widely used in clinical laboratories for measurement of plasma/serum concentrations of steroid hormones such as cortisol and testosterone. Immunoassays can be performed on a variety of standard clinical chemistry analyzers, thus allowing even small clinical laboratories to do analysis on-site. One limitation of steroid hormone immunoassays is interference caused by compounds with structural similarity to the target steroid of the assay. Interfering molecules include structurally related endogenous compounds and their metabolites as well as drugs such as anabolic steroids and synthetic glucocorticoids. Methods Cross-reactivity of a structurally diverse set of compounds were determined for the Roche Diagnostics Elecsys assays for cortisol, dehydroepiandrosterone (DHEA) sulfate, estradiol, progesterone, and testosterone. These data were compared and contrasted to package insert data and published cross-reactivity studies for other marketed steroid hormone immunoassays. Cross-reactivity was computationally predicted using the technique of two-dimensional molecular similarity. Results The Roche Elecsys Cortisol and Testosterone II assays showed a wider range of cross-reactivity than the DHEA sulfate, Estradiol II, and Progesterone II assays. 6-Methylprednisolone and prednisolone showed high cross-reactivity for the cortisol assay, with high likelihood of clinically significant effect for patients administered these drugs. In addition, 21-deoxycortisol likely produces clinically relevant cross-reactivity for cortisol in patients with 21-hydroxylase deficiency, while 11-deoxycortisol may produce clinically relevant cross-reactivity in 11?-hydroxylase deficiency or following metyrapone challenge. Several anabolic steroids may produce clinically significant false positives on the testosterone assay, although interpretation is limited by sparse pharmacokinetic data for some of these drugs. Norethindrone therapy may impact immunoassay measurement of testosterone in women. Using two-dimensional similarity calculations, all compounds with high cross-reactivity also showed a high degree of similarity to the target molecule of the immunoassay. Conclusions Compounds producing cross-reactivity in steroid hormone immunoassays generally have a high degree of structural similarity to the target hormone. Clinically significant interactions can occur with structurally similar drugs (e.g., prednisolone and cortisol immunoassays; methyltestosterone and testosterone immunoassays) or with endogenous compounds such as 21-deoxycortisol that can accumulate to very high concentrations in certain disease conditions. Simple similarity calculations can help triage compounds for future testing of assay cross-reactivity.

2014-01-01

357

The ethics of living donor lung transplantation.  

PubMed

A constant awareness of the risk to the living donors must be maintained with any living donor organ transplantation program, and comprehensive short- and long-term follow-up should be strongly encouraged to maintain the viability of these potentially life-saving procedures. There has been no perioperative or long-term mortality following lobectomy for living lobar lung transplantation, and perioperative risks associated with donor lobectomy seem to be similar to those seen with standard lung resections. These risks might increase, however, if the procedure is offered on an occasional basis and not within a well-established program. The long-term outcomes and functional effects of lobar donation raise important questions that are unanswered. This has proved difficult to follow closely, because of the fact that many donors live far from the transplant medical center and are reluctant to return for routine follow-up evaluation. The death of a recipient can further exacerbate this situation, because there is reluctance to insist on further routine examinations for a grieving donor. Prospective donors must be informed of the morbidity associated with lobectomy and the potential for mortality, and for potential negative recipient outcomes in regard to life expectancy and quality of life after transplantation. Although cadaveric transplantation must be considered because of the risk to the donors, living lobar lung transplantation should continue to be used under properly selected circumstances. The results reported by the authors' group and others are important if this procedure is to be considered as an option at more pulmonary transplant centers in view of the institutional, regional, and international differences in the philosophic and ethical acceptance of the use of living organ donors for transplantation. The integration of ethical discussion into topics that are relevant and of interest to thoracic surgeons, such as living lung donation, is a recent and welcome event. Many of the clinical situations that thoracic surgeons deal with on a daily basis have important and complex ethical implications, and there has been little training to deal effectively with these issues. This is changing as invited discussions on ethically compelling topics are finding their way into journals and the programs of national meetings. What may be of more importance, however, is the development of an ethics curriculum for those training in the specialty. The core curriculum recommended by the Thoracic Surgical Directors Association (which represents the leadership of the 89 approved residency training programs in the United States) has one lecture pertaining to ethics out of the several hundred offerings in its requisite curriculum. It is hoped that this will change in the near future. PMID:16276816

Wells, Winfield J; Barr, Mark L

2005-11-01

358

Risks for donors in uterus transplantation.  

PubMed

Uterus transplantation (UTx) is an alternative to gestational surrogacy and adoption for patients with absolute uterine infertility. Studies have been conducted in animals, and UTx is now within the reach of clinical application in humans. Procedures in humans have been published, but many medical, ethical, and social problems and risks of UTx require discussion prior to widespread clinical application, from the perspectives of donors, recipients, families, and newborns. In this article, we summarize the burdens and risks of UTx, with a focus on donors who provide the uterus. PMID:23793471

Kisu, Iori; Mihara, Makoto; Banno, Kouji; Umene, Kiyoko; Araki, Jun; Hara, Hisako; Suganuma, Nobuhiko; Aoki, Daisuke

2013-12-01

359

A pilot study on screening blood donors with individual-donation nucleic acid testing in China  

PubMed Central

Background Nucleic acid amplification testing (NAT) is not yet obligatory in China for blood donor screening and the risk of enzyme immunoassay (EIA)-negative, NAT-reactive donations in Chinese blood donors has rarely been reported. The aim of this study was to screen a population of Chinese blood donors using a triplex individual-donation (ID)-NAT assay and assess the safety benefits of implementing NAT. Materials and methods Between 1st August, 2010 and 31st December, 2011 all donations at a Chinese blood centre were screened individually using the Procleix® Ultrio® assay, a multiplex NAT assay for the detection of hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA and human immunodeficiency virus-1 (HIV-1) RNA. All donations were also screened for HBsAg, anti-HIV and anti-HCV using two different EIA for each marker. Samples with discordant results between NAT and EIA were further tested with an alternative NAT assay (Cobas® TaqMan®). Potential yield cases (serologically negative/NAT-reactive donors) were further evaluated when possible. Results During the study period a total of 178,447 donations were screened by NAT and EIA, among which 169 HBV NAT yield cases (0.095%) were detected. No N AT yield cases were found for HIV-1 or HCV. For the HBV NAT yield cases, follow-up results showed that 11 (6.51%) were probable or confirmed HBV window period infections, 5 (2.96%) were chronic HBV carriers and 153 (90.53%) were probable or confirmed occult HBV infections. There was a statistically significant difference between the NAT-positive rates for first-time vs repeat donations (0.472% vs 0.146%, respectively; P<0.001). Discussion Our data demonstrate that the potential HBV yield rate was 1:1,056 for blood donations in the Zhejiang province of China. Implementation of NAT will provide a significant increment in safety relative to serological screening alone.

Dong, Jie; Wu, Yaling; Zhu, Hong; Li, Gan; Lv, Mengen; Wu, Daxiao; Li, Xiaotao; Zhu, Faming; Lv, Hangjun

2014-01-01

360

Superfund Innovative Technology Evaluation Program demonstration plan for Westinghouse Bio-Analytic Systems pentachlorophenol immunoassays  

SciTech Connect

The 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. The immunoassays measure parts per billion concentrations of pentachlorophenol in water. The demonstration is being conducted under the Superfund Innovative Technology Evaluation (SITE) Program. It is expected that proper execution of the demonstration plan will provide information that enables data users and reviewers to assess the performance of the technology in terms of its usefulness and limitations for the Superfund Program. The main focus of the demonstration is to evaluate on site a semiquantitative immunoassay field analysis kit for its utility as a rapid field screening tool. The results obtained from the field kit analyses will be compared to those obtained from a quantitative high-sample-capacity plate immunoassay also developed by Westinghouse Bio-Analytic Systems. In addition, both immunoassay techniques will be compared to the standard gas chromatography/mass spectrometry procedure for pentachlorophenol determination. The quality assurance plan for the demonstration is provided in an appendix.

Silverstein, M.E.; White, R.J.; Gerlach, R.W.; Van Emon, J.M.

1992-04-14

361

Preprogrammed, parallel on-chip immunoassay using system-level capillarity control.  

PubMed

Fully manual use of conventional multiwell plates makes enzyme-linked immunosorbent assay (ELISA)-based immunoassays highly time-consuming and labor-intensive. Here, we present a capillarity-driven on-chip immunoassay that greatly saves time and labor with an inexpensive setup. Our immunoassay process starts with pipetting multiple solutions into multiwells constructed on a microfluidic device chip. Subsequently, capillarity spontaneously transports multiple sample solutions and common reagent solutions into assigned detection channels on the chip in a purely passive and preprogrammed manner. Our device implements capillarity-driven immunoassays involving four sample and six reagent solutions within 30 min by orchestrating the functions of on-chip passive components. Notably, our immunoassay technique reduces the total number of pipetting processes by ~5 times, as compared to assays on multiwell plates (48 vs 10). This assay technique allows us to quantify the concentrations of C-reactive protein and suppressor of tumorigenicity 2 with a detection limit of 8 and 90 pM, respectively. This device should be useful for sophisticated, parallel biochemical microfluidic processing in point-of-care settings under limited resources. PMID:23789820

Kim, Sung-Jin; Paczesny, Sophie; Takayama, Shuichi; Kurabayashi, Katsuo

2013-07-16

362

Analysis of amino-terminal variants of amyloid-? peptides by capillary isoelectric focusing immunoassay.  

PubMed

Here we present a novel assay for the separation and detection of amino-terminal amyloid-? (A?) peptide variants by capillary isoelectric focusing (CIEF) immunoassay. Specific amino-terminally truncated A? peptides appear to be generated by ?-secretase (BACE1)-independent mechanisms and have previously been observed in cerebrospinal fluid (CSF) after BACE1 inhibitor treatment in an animal model. CIEF immunoassay sensitivity is sufficient to detect total A? in CSF without preconcentration. To analyze low-abundance amino-terminally truncated A? peptides from cell culture supernatants, we developed a CIEF-compatible immunoprecipitation protocol, allowing for selective elution of A? peptides with very low background. CIEF immunoassay and immunoprecipitation mass spectrometry analysis identified peptides starting at residue Arg(5) as the main amino-terminal A? variants produced in the presence of tripartite BACE1 inhibitor in our cell culture model. The CIEF immunoassay allows for robust relative quantification of A? peptide patterns in biological samples. To assess the future possibility of absolute quantification, we have prepared the A? peptides A?(x-10), A?(x-16), and A?(5-38(D23S)) by using solid phase peptide synthesis as internal standards for the CIEF immunoassay. PMID:23889568

Haußmann, Ute; Jahn, Olaf; Linning, Philipp; Janßen, Christin; Liepold, Thomas; Portelius, Erik; Zetterberg, Henrik; Bauer, Chris; Schuchhardt, Johannes; Knölker, Hans-Joachim; Klafki, Hans; Wiltfang, Jens

2013-09-01

363

Molecular Similarity Methods for Predicting Cross-Reactivity With Therapeutic Drug Monitoring Immunoassays  

PubMed Central

Immunoassays are used for therapeutic drug monitoring (TDM) yet may suffer from cross-reacting compounds able to bind the assay antibodies in a manner similar to the target molecule. To our knowledge, there has been no investigation using computational tools to predict cross-reactivity with TDM immunoassays. The authors used molecular similarity methods to enable calculation of structural similarity for a wide range of compounds (prescription and over-the-counter medications, illicit drugs, and clinically significant metabolites) to the target molecules of TDM immunoassays. Utilizing different molecular descriptors (MDL public keys, functional class fingerprints, and pharmacophore fingerprints) and the Tanimoto similarity coefficient, the authors compared cross-reactivity data in the package inserts of immunoassays marketed for in vitro diagnostic use. Using MDL public keys and the Tanimoto similarity coefficient showed a strong and statistically significant separation between cross-reactive and non-cross-reactive compounds. Thus, two-dimensional shape similarity of cross-reacting molecules and the target molecules of TDM immunoassays provides a fast chemoinformatics methods for a priori prediction of potential of cross-reactivity that might be otherwise undetected. These methods could be used to reliably focus cross-reactivity testing on compounds with high similarity to the target molecule and limit testing of compounds with low similarity and ultimately with a very low probability of cross-reacting with the assay in vitro.

Krasowski, Matthew D.; Siam, Mohamed G.; Iyer, Manisha; Ekins, Sean

2010-01-01

364

2509 living donor nephrectomies, morbidity and mortality, including the UK introduction of laparoscopic donor surgery.  

PubMed

The worldwide expansion of laparoscopic, at the expense of open, donor nephrectomy (DN) has been driven on the basis of faster convalescence for the donor. However, concerns have been expressed over the safety of the laparoscopic procedure. The UK Transplant National Registry collecting mandatory information on all living kidney donations in the country was analyzed for donations between November 2000 (start of living donor follow-up data reporting) to June 2006 to assess the safety of living DN, after the recent introduction of the laparoscopic procedure in the United Kingdom. Twenty-four transplant units reported data on 2509 donors (601 laparoscopic, 1800 open and 108 [4.3%] unspecified); 46.5% male; mean donor age: 46 years. There was one death 3 months postdischarge and a further five deaths beyond 1 year postdischarge. The mean length of stay was 1.5 days less for the laparoscopic procedure (p < 0.001). The risk of major morbidity for all donors was 4.9% (laparoscopic = 4.5%, open = 5.1%, p = 0.549). The overall rate of any morbidity was 14.3% (laparoscopic = 10.3%, open = 15.7%, p = 0.001). Living donation has remained a safe procedure in the UK during the learning curve of introduction of the laparoscopic procedure. The latter offers measurable advantages to the donor in terms of reduced length of stay and morbidity. PMID:17868058

Hadjianastassiou, V G; Johnson, R J; Rudge, C J; Mamode, N

2007-11-01

365

Donor-conceived children looking for their sperm donor: what do they want to know?  

PubMed Central

Objective: This paper aims to gain in-depth understanding of why some donor-conceived offspring want to know the identity of their sperm donor. Methods: Step-by-step inductive thematic analysis was performed on first-hand quotes from donor-conceived offspring selected from a wide range of sources (including empirical studies and donor conception networks, registries and support groups). Results: We found that at least 7 different objectives can underlie the wish to know one’s donor: to avoid medical risks and consanguineous relationships; to connect with one’s roots; to complete one’s life (hi-)story; to understand where one’s traits come from; to discover or assess one’s defining characteristics and capabilities; to rectify a wrong-doing, and to map out one’s ancestral history. Conclusion: The analysis shows that there is great variance among identity-seekers in the weight they attribute to wanting to know their donor. It is also clear that they have very different assumptions about the role and importance of genetics in terms of establishing ‘who they are’ or ‘can become’, including deterministic misconceptions. Rather than treat all donor-conceived offspring’s needs as of equal concern, this analysis should help distinguish between and assess the relevance of the various motivations.

Ravelingien, A.; Provoost, V.; Pennings, G.

2013-01-01

366

Compliance with donor age recommendations in oocyte donor recruitment advertisements in the USA.  

PubMed

IVF using donated oocytes offers benefits to many infertile patients, yet the technique also raises a number of ethical concerns, including worries about potential physical and psychological risks to oocyte donors. In the USA, oversight of oocyte donation consists of a combination of federal and state regulations and self-regulatory guidelines promulgated by the American Society for Reproductive Medicine. This study assesses compliance with one of these self-regulatory guidelines - specifically, ASRM's preferred minimum age for donors of 21. To assess compliance, 539 oocyte donor recruitment advertisements from two recruitment channels (Craigslist and college newspapers) were collected and evaluated. Of these, 61% in the Craigslist dataset and 43% in the college newspaper dataset listed minimum ages between 18 and 20, which is inconsistent with ASRM's preferred minimum age recommendation of 21. Advertisements placed by oocyte donor recruitment agencies were more likely than advertisements placed by clinics to specify minimum ages between 18 and 20. These results indicate that ASRM should evaluate and consider revising its donor age guidelines. IVF using donated human eggs can help many patients who have difficulty having children. However, the technique also raises ethical concerns, including concerns about potential physical and psychological harms to egg donors. In the USA, oversight of egg donation relies on a combination of federal and state regulation and professional self-regulation. Governmental regulations address only limited aspects of egg donation, such as the potential spread of infectious diseases and the reporting of success rates, leaving voluntary guidelines developed by an association of medical professionals to address most issues, including ethical concerns raised by the practice. One of these voluntary guidelines recommends that egg donors should be at least 21 years of age. In this article, we analysed 539 egg donor recruitment advertisements published on Craigslist and in college newspapers to see whether fertility clinics and egg donor recruitment agencies follow this recommendation. We found that 61% of advertisements in the Craigslist dataset and 43% of advertisements in the college newspaper dataset listed minimum ages between 18 and 20 and, thus, did not follow the recommendation that egg donors be at least 21 years of age. Advertisements placed by egg donor recruitment agencies were more likely than advertisements placed by fertility clinics to list minimum ages between 18 and 20. These results indicate that the American Society for Reproductive Medicine should evaluate and consider revising its donor age guidelines. PMID:23337419

Alberta, Hillary B; Berry, Roberta M; Levine, Aaron D

2013-04-01

367

Characterization of a Rapid and Sensitive Enzyme Immunoassay (EIA) for Progesterone Applied to Conditioned Cell Culture Media  

Microsoft Academic Search

Progesterone accumulation in conditioned media is a frequently employed endpoint for in vitro cell culture of steroidogenic cells. Although radioimmunoassay (RIA) has been the predominant method for measurement of progesterone, a number of nonradiometric immunoassays have been described but they have not been applied to conditioned media. Here, we report the characterization of a microtitre plate enzyme immunoassay (EIA) for

Barry G. Kasson; Shuzhen Bai; James Liu; Chris Tobin; Bruce Kessel

1993-01-01

368

Effects of some hematological parameters on whole blood tacrolimus concentration measured by two immunoassay-based analytical methods  

Microsoft Academic Search

Objectives:Tacrolimus (FK506) is a potent immunosuppressive drug used for prevention of rejection following transplantation. Several methods including immunoassays have been used for monitoring tacrolimus levels. The purpose of the present study was to compare the effects of various hematological parameters on whole blood tacrolimus concentrations which were measured with two different analytical methods, namely the microparticle enzyme immunoassay (MEIA II)

S. Halide Akbas; Sebahat Ozdem; Serkan Caglar; Murat Tuncer; Alihan Gurkan; Levent Yucetin; Yesim Senol; Alper Demirbas; Meral Gultekin; F. Fevzi Ersoy; Mustafa Akaydin

2005-01-01

369

Comparison of infrared-excited up-converting phosphors and europium nanoparticles as labels in a two-site immunoassay  

Microsoft Academic Search

Research in the field of immunoassays and labels used in the detection has been recently focused on particulate reporters, which possess very high specific activity that excludes the label as a sensitivity limiting factor. However, the large size and shape of the particulate labels may produce additional problems to immunoassay performance. The aim of this work was to study with

Telle Ukonaho; Terhi Rantanen; Laura Jämsen; Katri Kuningas; Henna Päkkilä; Timo Lövgren; Tero Soukka

2007-01-01

370

Simultaneous detection of IgG antibodies associated with viral hemorrhagic fever by a multiplexed Luminex-based immunoassay.  

PubMed

Viral hemorrhagic fevers (VHFs) are worldwide diseases caused by several kinds of viruses. With the emergence of new viruses, advanced diagnostic methods are urgently needed for identification of VHFs. Based on Luminex xMAP technology, a rapid, sensitive, multi-pathogen and high-throughput method which could simultaneously detect hemorrhagic fever viruses (HFVs) specific IgG antibodies was developed. Recombinant antigens of nine HFVs including Hantaan virus (HTNV), Seoul virus (SEOV), Puumala virus (PUUV), Andes virus (ANDV), Sin Nombre virus (SNV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) and dengue virus (DENV) were produced and purified from a prokaryotic expression system and the influence of the coupling amount was investigated. Cross-reactions among antigens and their rabbit immune sera were evaluated. Serum samples collected from 51 laboratory confirmed hemorrhagic fever with renal syndrome (HFRS) patients, 43 confirmed SFTS patients and 88 healthy donors were analyzed. Results showed that recombinant nucleocapsid protein of the five viruses belonging to the genus Hantavirus, had serological cross-reactivity with their corresponding rabbit immune sera, but not apparent with immune sera of other four viruses. Evaluation of this new method with clinical serum samples showed 98.04% diagnostic sensitivity for HFRS, 90.70% for SFTS detection and the specificity was ranging from 66.67% to 100.00%. The multiplexed Luminex-based immunoassay has firstly been established in our study, which provides a potentially reliable diagnostic tool for IgG antibody detection of VHFs. PMID:24631566

Wu, Wei; Zhang, Shuo; Qu, Jing; Zhang, Quanfu; Li, Chuan; Li, Jiandong; Jin, Cong; Liang, Mifang; Li, Dexin

2014-07-17

371

Novel one-step immunoassays to quantify ?-synuclein: applications for biomarker development and high-throughput screening.  

PubMed

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. PMID:22843695

Bidinosti, Michael; Shimshek, Derya R; Mollenhauer, Brit; Marcellin, David; Schweizer, Tatjana; Lotz, Gregor P; Schlossmacher, Michael G; Weiss, Andreas

2012-09-28

372

Immunological and PCR Analyses for Borna Disease Virus in Psychiatric Patients and Blood Donors in Japan  

PubMed Central

The involvement of Borna disease virus (BDV) in psychiatric diseases in humans remains controversial. T-cell memory response and seroprevalence of BDV in patients with psychiatric disorders and blood donors in Japan were evaluated collectively by Western blot (WB) analysis with inhibition test, electrochemiluminescence immunoassay, immunofluorescence assay, and T-cell proliferative response as well as detection of BDV p24 RNA in peripheral blood mononuclear cells (PBMCs). Positive proliferative responses to both BDV p40 and p24 proteins were detected in 9% of patients with mood disorders (4 of 45), 4% of schizophrenic patients (2 of 45), and 2% of blood donors (1 of 45). By WB analysis, the antibody to BDV p40 was detected only in 2% of patients with mood disorders (1 of 45). The BDV p24 antibody was detected in 2% of patients with mood disorders (1 of 45) and 9% of schizophrenic patients. (4 of 45) No plasma reacted with both BDV proteins. The finding of a lower seroprevalence than previously reported suggests the presence of false-positive cases in the previous report. BDV RNA was detected only in 2% of patients with mood disorders (1 of 45). In these three serological assays, T-cell responses, and PCR analysis, there was no significant difference in the prevalence among the three groups. However, we found three psychiatric patients who were positive for both BDV antibodies and T-cell proliferative responses and one patient who was positive for BDV RNA in PBMCs. These findings suggest the usefulness of the proliferative T-cell response and that certain individuals are infected with BDV or a BDV-related virus.

Fukuda, Koji; Takahashi, Kazuo; Iwata, Yasuhide; Mori, Norio; Gonda, Kenji; Ogawa, Tsuguhiro; Osonoe, Kouichi; Sato, Minako; Ogata, Shin-ichi; Horimoto, Taisuke; Sawada, Takashi; Tashiro, Masato; Yamaguchi, Kazunari; Niwa, Shin-ichi; Shigeta, Shiro

2001-01-01

373

Ex Vivo Evaluation of Nonacceptable Donor Lungs  

Microsoft Academic Search

Background. Only a minority of the potential candi- dates for lung donation are considered suitable, using current evaluation methods. A new method for ex vivo evaluation, with the potential for reconditioning of mar- ginal and nonacceptable lungs, has been developed. This is a report of the ex vivo evaluation of six donor lungs deemed nonacceptable (arterial oxygen pressure less than

Per Wierup; Åsa Haraldsson; Folke Nilsson; Leif Pierre; Henrik Scherstén; Martin Silverborn; Trygve Sjöberg; Ulla Westfeldt; Stig Steen

2006-01-01

374

Hydrogen-donor coal liquefaction process  

DOEpatents

Improved liquid yields are obtained during the hydrogen-donor solvent liquefaction of coal and similar carbonaceous solids by maintaining a higher concentration of material having hydrogenation catalytic activity in the downstream section of the liquefaction reactor system than in the upstream section of the system.

Wilson, Jr., Edward L. (Baytown, TX); Mitchell, Willard N. (Baytown, TX)

1980-01-01

375

Selection against genetic defects in semen donors.  

PubMed

Artificial insemination donor selection requires predicting which men are likely to beget the healthiest offspring. Methods are developed for calculating the "offspring excess recurrence risk", delta R, for an anomaly in the offspring of an afflicted father. Mainly from published family survey and population data delta R is computed for 38 disorders. From a small survey a value for the with-treatment "affliction burden", Bt, is assigned to each anomaly. For each disorder the "offspring excess burden expectation" is delta RBt. Defects such as cataract, hereditary Parkinson disease, psoriasis, seropositive rheumatoid arthritis, and schizophrenia have such a high delta RBt that they are individually sufficient cause for rejecting a donor candidate. A candidate may be rejected because of a combination of lesser defects with sigma delta RBt exceeding an acceptable limit. A limit should also be placed on Bt, because the affliction burden for Tay-Sachs disease or cystic fibrosis is intolerable, however infrequent. Most of the important hereditary defects are late onset, and for the older donor the opportunity to select more directly against late-onset disorders offsets the added risk of newly-arising gene mutations. The most careful donor selection cannot completely eliminate the risk of a child inheriting some disorder, but selection can reduce the average total burden by as much as 17%. PMID:6467672

Smith, P E

1984-08-01

376

Role of DR-70 immunoassay in suspected malignant pleural effusion  

PubMed Central

Context: A good proportion of patients with undiagnosed pleural effusion (PE) turn into malignancy over a period of time. Identification of positive biomarker may help in selecting the individuals who require close follow-up. Aims: The aims of this study were to evaluate the role of DR-70 immunoassay in suspected malignant PE. Settings and Design: We conducted a cross-sectional study among 89 patients of suspected malignant PE and 50 normal subjects (NS) were taken as control. Materials and Methods: Patients with exudative PE; who had pleural fluid lymphocyte count greater than 50% and adenosine deaminase less than 30 U/L were taken as cases. We had selected NSs among relatives of patients having normal blood chemistry and radiological investigations. Sensitivity and specificity of the test to differentiate malignant and non-malignant PE and also to identify PE with underlying malignancy was analyzed. Results: Mean value of DR-70 in NS was found to be 0.83 ± 0.273 mg/L without any significant difference between males (0.82 mg/L) and females (0.85 mg/L). Mean value of DR-70 in PE with underlying cancer was 5.03 ± 3.79 mg/L. Sensitivity (80%) and specificity (77.78%) of the test was maximum in PE with underlying cancer using cut-off value of 2 mg/L. Mean value DR-70 in malignant PE was 5.18 ± 3.75 mg/L and in non-malignant PE was 3.73 ± 3.74 mg/L without any statistically significant difference (P = 0.08). Conclusions: DR-70 assay has high sensitivity in detecting underlying lung cancer, but has no role in differentiating malignant PE from non-malignant PE.

Sengupta, Amitabha; Saha, Kaushik; Jash, Debraj; Banerjee, Sourindra Nath; Biswas, Nirendra Mohan; Dey, Atin

2013-01-01

377

Quantitation of Immunoglobulin to Hepatitis E Virus by Enzyme Immunoassay  

PubMed Central

We developed a quantitative enzyme immunoassay (EIA) for antibody to hepatitis E virus (HEV) by using truncated HEV capsid protein expressed in the baculovirus system to improve seroepidemiology, to contribute to hepatitis E diagnosis, and to enable vaccine evaluations. Five antigen lots were characterized; we used a reference antiserum to standardize antigen potency. We defined Walter Reed antibody units (WR U) with a reference antiserum by using the four-parameter logistic model, established other reference pools as assay standards, and determined the conversion factor: 1 WR U/ml = 0.125 World Health Organization unit (WHO U) per ml. The EIA performed consistently; median intra- and intertest coefficients of variation were 9 and 12%, respectively. The accurate minimum detection limit with serum diluted 1:1,000 was 5.6 WR U/ml; the test could detect reliably a fourfold antibody change. In six people followed from health to onset of hepatitis E, the geometric mean antibody level rose from 7.1 WR U/ml to 1,924.6 WR U/ml. We used the presence of 56- and 180-kDa bands by Western blotting as a confirmatory test and to define true-negative and -positive serum specimens. A receiver-operating characteristics plot identified 30 WR U/ml as an optimum cut-point (sensitivity, 86%; specificity, 89%). The EIA detected antibody more sensitively than a commercially available test. The EIA was transferred to another laboratory, where four operators matched reference laboratory results for a panel of unknowns. Quantitation of antibody to HEV and confirmation of its specificity by Western blotting make HEV serology more meaningful.

Innis, Bruce L.; Seriwatana, Jitvimol; Robinson, Robin A.; Shrestha, Mrigendra P.; Yarbough, Patrice O.; Longer, Charles F.; Scott, Robert M.; Vaughn, David W.; Myint, Khin Saw Aye

2002-01-01

378

Solid-phase competitive luminescence immunoassay for lysozyme in faeces.  

PubMed

We have developed a new simple solid-phase luminescence immunoassay (LIA) for the determination of faecal lysozyme. The assay utilises a polyclonal capture antibody coated to polystyrene beads and acridinium ester-labelled human lysozyme as tracer. Samples are incubated with polystyrene beads and tracer overnight at 4 degrees C. After a thorough washing step, emitted light is measured by an automated luminometer for 2 seconds. The standard curve uses five standards ranging from 0.025 to 6.4 mg/l. The method has a sensitivity of 0.02 mg/l. Dilution recoveries for three samples were 88, 104 and 108%. Intraassay coefficients of variation (CV, n = 24) were 10.1% and 11.7% for a healthy control and a patient sample; interassay CV (n = 16) were 6.7% and 13.1% for the same healthy control but another patient sample. The normal range of faecal lysozyme in 80 healthy controls was found to be 0.02-1 mg/l (97.5 percentile) with a median of 0.28 mg/l. Fifty-three patients with Crohn's disease had faecal lysozyme values ranging from 0.16 to 100.7 mg/l with a median of 1.75 mg/l, and 30 patients with ulcerative colitis showed levels between 0.09 and 118 mg/l with a median of 1.11 mg/l. The assay has proved useful for differentiating healthy individuals from those with inflammatory bowel disease and might be a valuable tool for diagnosing or evaluating inflammatory bowel disease. PMID:8542654

Gao, P; John, M R; Schmidt-Gayk, H; Arndt, B; Scheida, M; Theuer, D

1995-08-14

379

Amperometric homogeneous competitive immunoassay in a perfluorocarbon emulsion oxygen therapeutic (PEOT).  

PubMed

The effect of a perfluorocarbon emulsion oxygen therapeutic (PEOT) on the detection of the drugs theophylline and phenytoin was explored using a commercial enzyme multiplied immunoassay technique (EMIT®). The EMIT technique is based on the enzymatic production of NADH, which is typically detected in serum samples spectrophotometrically. Here, amperometry using the rotating disk electrode on a single drop of solution is demonstrated to detect theophylline and phenytoin in the presence of PEOT. In the study, 2,6-dichloroindophenol (DCIP) added to the immunoassay mixture is reduced by the NADH to DCIPH2. Oxidation of DCIPH2 is monitored electrochemically at +200 mV using a glassy carbon rotating disk electrode. Slopes of amperograms are proportional to the concentration of drug in the immunoassay sample. This technique yields excellent quantitative data in the therapeutic range for both drugs in 2-20% PEOT. PMID:23104312

Barlag, Rebecca E; Halsall, H Brian; Heineman, William R

2013-04-01

380

Characterization of Magnetic Markers for Liquid-Phase Immunoassays Using Brownian Relaxation  

NASA Astrophysics Data System (ADS)

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.

Enpuku, Keiji; Watanabe, Hideki; Higuchi, Yuichi; Yoshida, Takashi; Kuma, Hiroyuki; Hamasaki, Naotaka; Mitsunaga, Masakazu; Kanzaki, Hisao; Kandori, Akihiko

2012-02-01

381

Optimizing Two-Color Semiconductor Nanocrystal Immunoassays in Single Well Microtiter Plate Formats  

PubMed Central

The simultaneous detection of two analytes, chicken IgY (IgG) and Staphylococcal enterotoxin B (SEB), in the single well of a 96-well plate is demonstrated using luminescent semiconductor quantum dot nanocrystal (NC) tracers. The NC-labeled antibodies were prepared via sulfhydryl-reactive chemistry using a facile protocol that took <3 h. Dose response curves for each target were evaluated in a single immunoassay format and compared to Cy5, a fluorophore commonly used in fluorescent immunoassays, and found to be equivalent. Immunoassays were then performed in a duplex format, demonstrating multiplex detection in a single well with limits of detection equivalent to the single assay format: 9.8 ng/mL chicken IgG and 7.8 ng/mL SEB.

Sapsford, Kim E.; Spindel, Samantha; Jennings, Travis; Tao, Guoliang; Triulzi, Robert C.; Algar, W. Russ; Medintz, Igor L.

2011-01-01

382

Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource-limited settings.  

PubMed

Introduction: Therapeutic drug monitoring (TDM) may improve antiretroviral efficacy through adjustment of individual drug administration. This could result in reduced toxicity, prevent drug resistance, and aid management of drug-drug interactions. However, most measurement methods are too costly to be implemented in resource-limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz. Methods: The immunoassay-based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations measured by the immunoassay with liquid chromatography tandem mass spectrometry (LC-MS/MS) (reference method) in 315 plasma samples collected from HIV patients on treatment. Concentrations were categorized as suboptimal<1 µg/ml, normal 1-4 µg/ml or high>4 µg/ml. Agreement between results of the methods was assessed via Bland-Altman plot and ? statistic values. Results: The median Interquartile range (IQR) efavirenz concentration was 2.8 (1.9; 4.5) µg/ml measured by the LC-MS/MS method and 2.5 (1.8; 3.9) µg/ml by the immunoassay and the results were well correlated (?=0.94). The limits of agreement assessed by Bland-Altman plots were -2.54; 1.70 µg/ml. Although immunoassay underestimated high concentrations, it had good agreement for classification into low, normal or high concentrations (K=0.74). Conclusions: The immunoassay is a feasible alternative to determine efavirenz in areas with limited resources. The assay provides a reasonable approximation of efavirenz concentration in the majority of samples with a tendency to underestimate high concentrations. Agreement between tests evaluated in this study was clinically satisfactory for identification of low, normal and high efavirenz concentrations. PMID:24909561

Abdissa, Alemseged; Wiesner, Lubbe; McIlleron, Helen; Friis, Henrik; Andersen, Ase Bengård; Kæstel, Pernille

2014-01-01

383

Evaluation of an immunoassay for determination of plasma efavirenz concentrations in resource-limited settings  

PubMed Central

Introduction Therapeutic drug monitoring (TDM) may improve antiretroviral efficacy through adjustment of individual drug administration. This could result in reduced toxicity, prevent drug resistance, and aid management of drug–drug interactions. However, most measurement methods are too costly to be implemented in resource-limited settings. This study evaluated a commercially available immunoassay for measurement of plasma efavirenz. Methods The immunoassay-based method was applied to measure efavirenz using a readily available Humastar 80 chemistry analyzer. We compared plasma efavirenz concentrations measured by the immunoassay with liquid chromatography tandem mass spectrometry (LC-MS/MS) (reference method) in 315 plasma samples collected from HIV patients on treatment. Concentrations were categorized as suboptimal<1 µg/ml, normal 1–4 µg/ml or high>4 µg/ml. Agreement between results of the methods was assessed via Bland-Altman plot and ? statistic values. Results The median Interquartile range (IQR) efavirenz concentration was 2.8 (1.9; 4.5) µg/ml measured by the LC–MS/MS method and 2.5 (1.8; 3.9) µg/ml by the immunoassay and the results were well correlated (?=0.94). The limits of agreement assessed by Bland–Altman plots were ?2.54; 1.70 µg/ml. Although immunoassay underestimated high concentrations, it had good agreement for classification into low, normal or high concentrations (K=0.74). Conclusions The immunoassay is a feasible alternative to determine efavirenz in areas with limited resources. The assay provides a reasonable approximation of efavirenz concentration in the majority of samples with a tendency to underestimate high concentrations. Agreement between tests evaluated in this study was clinically satisfactory for identification of low, normal and high efavirenz concentrations.

Abdissa, Alemseged; Wiesner, Lubbe; McIlleron, Helen; Friis, Henrik; Andersen, Ase Bengard; Kaestel, Pernille

2014-01-01

384

Using cheminformatics to predict cross reactivity of "designer drugs" to their currently available immunoassays  

PubMed Central

Background A challenge for drug of abuse testing is presented by ‘designer drugs’, compounds typically discovered by modifications of existing clinical drug classes such as amphetamines and cannabinoids. Drug of abuse screening immunoassays directed at amphetamine or methamphetamine only detect a small subset of designer amphetamine-like drugs, and those immunoassays designed for tetrahydrocannabinol metabolites generally do not cross-react with synthetic cannabinoids lacking the classic cannabinoid chemical backbone. This suggests complexity in understanding how to detect and identify whether a patient has taken a molecule of one class or another, impacting clinical care. Methods Cross-reactivity data from immunoassays specifically targeting designer amphetamine-like and synthetic cannabinoid drugs was collected from multiple published sources, and virtual chemical libraries for molecular similarity analysis were built. The virtual library for synthetic cannabinoid analysis contained a total of 169 structures, while the virtual library for amphetamine-type stimulants contained 288 compounds. Two-dimensional (2D) similarity for each test compound was compared to the target molecule of the immunoassay undergoing analysis. Results 2D similarity differentiated between cross-reactive and non-cross-reactive compounds for immunoassays targeting mephedrone/methcathinone, 3,4-methylenedioxypyrovalerone, benzylpiperazine, mephentermine, and synthetic cannabinoids. Conclusions In this study, we applied 2D molecular similarity analysis to the designer amphetamine-type stimulants and synthetic cannabinoids. Similarity calculations can be used to more efficiently decide which drugs and metabolites should be tested in cross-reactivity studies, as well as to design experiments and potentially predict antigens that would lead to immunoassays with cross reactivity for a broader array of designer drugs.

2014-01-01

385

Panchromatic donor-acceptor-donor conjugated oligomers for dye-sensitized solar cell applications.  

PubMed

We report on a sexithienyl and two donor-acceptor-donor oligothiophenes, employing benzothiadiazole and isoindigo as electron-acceptors, each functionalized with a phosphonic acid group for anchoring onto TiO2 substrates as light-harvesting molecules for dye sensitized solar cells (DSSCs). These dyes absorb light to wavelengths as long as 700 nm, as their optical HOMO/LUMO energy gaps are reduced from 2.40 to 1.77 eV with increasing acceptor strength. The oligomers were adsorbed onto mesoporous TiO2 films on fluorine doped tin oxide (FTO)/glass substrates and incorporated into DSSCs, which show AM1.5 power conversion efficiencies (PCEs) ranging between 2.6% and 6.4%. This work demonstrates that the donor-acceptor-donor (D-A-D) molecular structures coupled to phosphonic acid anchoring groups, which have not been used in DSSCs, can lead to high PCEs. PMID:24807377

Stalder, Romain; Xie, Dongping; Islam, Ashraful; Han, Liyuan; Reynolds, John R; Schanze, Kirk S

2014-06-11

386

?-D-glucosidase assisted gold dissolution as non-optical and quantifiable detection technique for immunoassays.  

PubMed

Immunoassays are used for detecting protein targets for various applications. Here, a modification of immunoassays to allow a purely electrical detection of the target protein concentration is shown. The modification comprises a ?-D-glucosidase as reporter enzyme and a cyanogenic glycoside as substrate. The enzymatic reaction produces cyanide in small quantities. For electrical detection of the cyanide, a novel sensor is developed, based on a gold micro wire. The cyanide dissolves the gold wire and changes the electrical resistance of the wire. Monitoring the resistance change allows a quantitative measurement of the target human C-reactive protein (an inflammatory marker) in blood plasma in the physiological relevant concentration range. PMID:23670861

Koehler, F M; Raso, R A; Grass, R N; Stark, W J

2013-12-01

387

The infrared fingerprint signals of silica nanoparticles and its application in immunoassay  

NASA Astrophysics Data System (ADS)

Infrared absorption properties of silica nanoparticles were studied. The transverse optical and the longitudinal optical phonon modes from the silica were proved to be the characteristic spectroscopic fingerprint signals. Based on this, a sandwich-structured immunoassay was performed, and the detection of the analyte (human IgG) was achieved by using biofunctional silica nanoparticles as infrared probes. The immunoassay based on Fourier transform infrared reflection absorption spectroscopy of silica nanoparticles shows significant value for potential applications in many areas, such as biomedicine, food safety, and waste treatment.

Ding, Yadan; Chu, Xueying; Hong, Xia; Zou, Peng; Liu, Yichun

2012-01-01

388

Stool diagnosis of giardiasis using a commercially available enzyme immunoassay to detect Giardia-specific antigen 65 (GSA 65).  

PubMed Central

A commercially available enzyme immunoassay for the diagnosis of giardiasis was evaluated in a clinical trial. The ProSpecT/Giardia diagnostic test (Alexon, Inc., Mountain View, Calif.) was compared with the standard ova and parasite (O&P) microscopic examination. Additionally, several widely used stool fixatives and a commonly used transport medium were assessed for compatibility with the immunoassay. A total of 325 stool specimens were collected and used to evaluate assay performance. Of those, 93 specimens were collected from symptomatic Giardia O&P-positive patients and 232 specimens were randomly collected from patients as part of a routine health screening procedure. All 93 Giardia O&P-positive stool specimens were strongly positive by visual and spectrophotometric examination using the immunoassay. Of the 232 randomly collected specimens, 16 were positive by O&P examination and immunoassay, 6 were negative by O&P examination but positive by immunoassay, and 1 was positive by O&P examination and negative by immunoassay. There was substantial supportive evidence that indicated that the six immunoassay-positive, O&P-negative specimens were true-positives. When these six specimens were accepted as true-positives, the immunoassay detected almost 30% more cases of Giardia infection than did O&P examination. Its sensitivity and specificity were 96 and 100%, respectively, while the sensitivity and specificity of O&P examination were 74 and 100%, respectively. The immunoassay also performed well on specimens treated with 10% neutral Formalin, sodium acetate-Formalin fixative, and Cary-Blair transport medium. However, the test was not compatible with polyvinyl alcohol-treated specimens. Overall, the ProSpecT/Giardia test was a sensitive, specific immunoassay which was easy to run and interpret. It offers a simple solution to traditional difficulties encountered in diagnosing Giardia infection.

Rosoff, J D; Sanders, C A; Sonnad, S S; De Lay, P R; Hadley, W K; Vincenzi, F F; Yajko, D M; O'Hanley, P D

1989-01-01

389

[Quantitative monitoring of multi-donor chimerism after multi-donor allogeneic hematopoietic stem cell transplantation].  

PubMed

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

Feng, Yu-Feng; Zhang, Xiang; Chen, Guang-Hua; Xu, Yang; Gong, Fei-Ran; Zhu, Zi-Ling; Dai, Li-Jun; Song, Tie-Mei; Zhou, Jia-Zi; Tang, Xiao-Wen; Chang, Hui-Rong; Miao, Jing-Cheng; Wu, De-Pei

2013-04-01

390

21 CFR 640.73 - Reporting of fatal donor reactions.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.73 Reporting of fatal donor reactions. If a donor has a fatal reaction which, in any way, may be...

2010-04-01

391

21 CFR 640.66 - Immunization of donors.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.66 Immunization of donors. If specific immunization of a donor is to be performed, the selection...

2010-04-01

392

21 CFR 640.66 - Immunization of donors.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.66 Immunization of donors. If specific immunization of a donor is to be performed, the selection...

2012-04-01

393

21 CFR 640.73 - Reporting of fatal donor reactions.  

Code of Federal Regulations, 2012 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.73 Reporting of fatal donor reactions. If a donor has a fatal reaction which, in any way, may be...

2012-04-01

394

21 CFR 640.73 - Reporting of fatal donor reactions.  

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.73 Reporting of fatal donor reactions. If a donor has a fatal reaction which, in any way, may be...

2014-04-01

395

21 CFR 640.66 - Immunization of donors.  

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.66 Immunization of donors. If specific immunization of a donor is to be performed, the selection...

2014-04-01

396

21 CFR 640.73 - Reporting of fatal donor reactions.  

Code of Federal Regulations, 2011 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.73 Reporting of fatal donor reactions. If a donor has a fatal reaction which, in any way, may be...

2011-04-01

397

Effects of Cellular Sensitization and Donor Age on Acute Rejection and Graft Function After Deceased-Donor Kidney Transplantation  

PubMed Central

Background Allografts from older donors may be more immunogenic than those from younger donors. Pretransplantation cellular sensitization may interact with advanced donor age to increase the risk of immune injury after deceased-donor kidney transplantation. Methods The outcomes of 118 consecutive deceased-donor kidney transplant recipients with available pretransplantation donor-stimulated enzyme-linked immunosorbent spot (ELISPOT) assays for interferon gamma were analyzed retrospectively to determine the impact of cellular sensitization and other clinical variables, including donor age, on the incidence of acute rejection (AR) in the first year after deceased-donor transplantation and on estimated glomerular filtration rate 12 months after transplantation. Results The incidence of AR was higher in patients with positive pretransplantation ELISPOT assays versus those with negative assays (36% vs. 14%, P=0.009). Logistic regression indicated that the combination of donor age 50 years or older and a positive pretransplantation ELISPOT assay was more strongly associated with AR (odds ratio, 12.1; confidence interval, 1.1–133) than either variable alone. Estimated glomerular filtration 12 months after transplantation was highest in ELISPOT-negative patients receiving kidneys from donors younger than 50 years and lowest in ELISPOT-positive recipients with donors 50 years or older. Conclusion The combination of advanced donor age and pretransplantation cellular sensitization increases the risk of AR and poor graft function after deceased-donor kidney transplantation beyond the risk associated with each factor alone.

Hricik, Donald E.; Poggio, Emilio D.; Woodside, Kenneth J.; Sarabu, Naragaju; Sanchez, Edmund Q.; Schulak, James A.; Padiyar, Aparna; Heeger, Peter S.; Augustine, Joshua J.

2014-01-01

398

Liver regeneration and splenic enlargement in donors after living-donor liver transplantation.  

PubMed

Liver regeneration after donor hepactectomy offers a unique insight into the process of liver regeneration in normal livers. As the liver restores itself, concurrent splenic enlargement occurs. There are many theories about why this phenomenon takes place: some investigators have proposed a relative portal hypertension that leads to splenic congestion or, perhaps, the presence of a common growth factor that induces both the liver and spleen to enlarge. Between the months of June 2001 and May 2004, 112 live donor liver transplants (LDLTs) were performed in Chang Gung Memorial Hospital, Kaohsiung, Taiwan. The total number of donor hepatectomies performed during this period was 113, however, because one of the cases required dual donors. Of our 113 donors, we eventually analyzed the data of 109; 4 patients were lost to follow-up 6 months later and were excluded from our study. The average age of our donor population was 32.32 +/- 8.48 years. The mean liver volume at donation was noted to be 1207.72 +/- 219.95 cm3, and 6 months later, it was 1027.18 +/- 202.41 cm3. Expressed as a percentage of the original volume, the mean liver volume 6 months after hepatectomy was 90.70% +/- 12.47% in this series. For right graft donors, mean liver volume after 6 months was 89.68% +/- 12.37% of the original liver volume, whereas that for left graft donors was 91.99% +/- 12.6%. Only 26 of the 109 (23.85%) donors were able to achieve full regeneration 6 months post-donation. Notably, liver function profiles of all donors were normal when measured 6 months after operation. The average splenic volume at donation as measured by computed tomography (CT) volumetry was 159 +/- 58 cm3, and the splenic volume 6 months post-donation was 213 +/- 85 cm3. There was a mean increment in splenic volume of 35% +/- 28% 6 months after donation. The blood profiles of the donors were monitored; particular attention was given to platelet levels and liver function tests, and these were found to be within normal limits 6 months after operation. Of note, splenic enlargement was significantly greater among right-sided donors than their left-sided counterparts. Greater splenic enlargement was also observed in those donors who achieved full liver regeneration at their evaluation 6 months postoperatively than in those who did not. Although original liver volume was not re-established in most patients 6 months after liver donation, there seemed to have been no untoward effects to the donor. The factors that affect liver regeneration are complex and myriad. Although there is splenic enlargement at 6 months post-donation in donors of LDLT, there are no untoward effects of this enlargement. PMID:16311869

Ibrahim, Salleh; Chen, Chao-Long; Wang, Chih-Chi; Wang, Shih-Ho; Lin, Chih-Che; Liu, Yeuh-Wei; Yang, Chin-Hsiang; Yong, Chee-Chien; Concejero, Allan; Cheng, Yu-Fan

2005-12-01

399

Preventing seroma in the latissimus dorsi flap donor site  

Microsoft Academic Search

A technique for preventing seroma in latissimus dorsi flap donor sites is presented. The procedure involves quilting the donor site skin flaps to the underlying tissues with absorbable sutures.In a single surgeon series, a retrospective group (n=16) of non-quilted donor sites was compared to a prospective group of quilted donor sites (n =11). The age range and indications for surgery

O. G. Titley; G. E. Spyrou; M. F. T. Fatah

1997-01-01

400

Committee of Donor Agencies for Small Enterprise Development  

NSDL National Science Digital Library

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.

401

Evaluation of Living Donor Liver Transplantation: Causes for Exclusion  

Microsoft Academic Search

The decision to perform organ donation surgery involves a series of risks for the live donor including death. The aim of this study was to evaluate exclusion criteria for living donor liver transplantation, as well as to identify the rate of exclusion in each of the 3 process phases according to the Live Donor Evaluation Protocol for adult and child

C. C. V. Araújo; E. Balbi; L. F. Pacheco-Moreira; M. Enne; J. Alves; R. Fernandes; K. Steinbrück; J. M. Martinho

2010-01-01

402

Searching for alternative hematopoietic stem cell donors for pediatric patients  

Microsoft Academic Search

The use of alternative hematopoietic stem cell (HSC) donors has been witnessing important progress, mainly due to: (i) better HLA matching at the allelic level between donor and recipient in unrelated HSC transplantation (HSCT) translating into better patient outcome; (ii) better donor choice and patient selection in unrelated, often HLA-mismatched, cord blood transplantation and (iii) new strategies of adoptive cell

V Rocha; F Locatelli

2008-01-01

403

Mating by proxy: a novel perspective to donor conception.  

PubMed

How single, partnered lesbian, and partnered heterosexual women undertaking donor insemination rate the importance of donor characteristics is explored in the context of Trivers's parental investment theory. Consistent with this theory, single women placed higher value on biographical traits reflective of the donor's level of potential resources (occupation, hobbies, age) and good character compared with either partnered lesbian or heterosexual women. PMID:21821248

Rodino, Iolanda S; Burton, Peter J; Sanders, Katherine A

2011-10-01

404

Do donors promote corruption?: the case of Mozambique  

Microsoft Academic Search

ABSTRACT Donors inveigh against corruption, yet give more aid to corrupt governments. Debate continues on the causes of developing country corruption, but with little consideration of the possibility that the behaviour of donors may unintentionally promote corruption. This article looks at the example of Mozam-bique, where corruption grew rapidly in the 1990s. It argues that the donor community is prepared

Joseph Hanlon

2004-01-01

405

Serum testosterone measurement in men: evaluation of modern immunoassay technologies.  

PubMed

Accurate measurement of serum testosterone (T) is essential for proper diagnosis of androgen deficiency. There are now several modern assay technologies, including automated ones, for measurement of T. In this study, we compared analytical performance of five modern immunoassay technologies commonly used for measurement of total T: Vitros ECi (Ortho-Clinical Diagnostics; normal range (n.r.) 4.6-34 nmol/L); Architect (Abbott Laboratories; n.r. 9.7-34 nmol/L); Access (Beckman Coulter; n.r. 5.3-23 nmol/L); Delfia (Perkin-Elmer; n.r. 9.3-34 nmol/L); and manual EIA DRG kits (n.r. 8.3-42 nmol/L), with the classical RIA (3H-T), after extraction (n.r. 11-33 nmol/L), as a reference method. Total T was measured using all above-mentioned methods in serum samples from 100 male patients, aged 16-65 years. Mean T concentrations in these 100 serum samples assayed by all non-isotopic methods were statistically significantly higher than those obtained by RIA. Delfia showed the highest T levels (19.3 nmol/L versus 12.1 nmol/L by RIA) with a positive bias 60-100%. Almost similar results were obtained using Architect, with a positive bias 40-70%. The closest correlation in results was found between Vitros ECi and RIA (12.7 nmol/L versus 12.1 nmol/L). In the studied samples, the median of differences ranged from minimal (-0.4 nmol/L for Vitros ECi) to maximal (-7.25 nmol/L for Delfia). For all non-isotopic methods, with the exception of Vitros ECi, differences in subjects with low T level (< 10 nmol/L) were statistically significantly larger than in the subjects with high T (T > 10 nmol/L). All other methods showed different degrees of dissimilarities with the RIA, especially in the range of low testosterone concentrations, which is of importance in the clinical assessment of women and pubertal boys. PMID:16390746

Goncharov, N; Katsya, G; Dobracheva, A; Nizhnik, A; Kolesnikova, G; Todua, T; Lunenfeld, B

2005-01-01

406

First fully automated immunoassay for anti-Müllerian hormone.  

PubMed

Abstract Background: The increasing importance of anti-Müllerian hormone (AMH) for the assessment of ovarian reserve requires accurate AMH measurements. There have been conflicting results about the reliability of currently existing manual AMH assays. Methods: Development of a high sensitive, fast and fully automated AMH assay on the Elecsys®/cobas e electrochemiluminescence immunoassay platform. Results: Elecsys® AMH is a monoclonal two-site assay used to measure AMH in 50 µL of serum or lithium heparin plasma in about 18 min. Its measuring range is from 0.01 to 23 ng/mL. The assay detects primarily 140 kDa total AMH (proAMH and AMHN,C). Standardization was against the Beckman AMH Gen II. Recovery against the highly cited Immunotech calibration was about 90%. Within-run imprecision coefficient of variation (CV) calculated on 10 serum samples were between 0.5% and 1.8%. Repeatability and intermediate precision calculated on 14 serum samples ranged from 2.6% to 1.7% and 2.9% to 2.1%, respectively. Limit of detection (LoD) [limit of quantitation (LoQ)] was 0.01 ng/mL (0.03 ng/mL). Percent recovery in dilution studies was <10% and after mixing of high and low AMH pools 94% to 103%. Elecsys® AMH, when compared to revised AMH Gen II (or Ansh Labs ultrasensitive AMH ELISA) using 57 female serum samples yielded a correlation coefficient of 0.98 (0.97) and a slope of 0.81 (0.73). There was no evidence for sample instability or variability. Samples stored at 20-25 °C or 2-8 °C up to 7 days showed no significant storage issues. Freeze-thaw cycles or sample storage at -20 °C and -80 °C for up to 9 months was without any effect on measured AMH. Conclusions: Availability of an automated Elecsys® AMH assay offers an attractive alternative to the current manual AMH assays. PMID:24622790

Gassner, Dieter; Jung, Rebecca

2014-08-01

407

Bead-based microfluidic immunoassay for diagnosis of Johne's disease  

SciTech Connect

Microfluidics technology offers a platform for development of point-of-care diagnostic devices for various infectious diseases. In this study, we examined whether serodiagnosis of Johne s disease (JD) can be conducted in a bead-based microfluidic assay system. Magnetic micro-beads were coated with antigens of the causative agent of JD, Mycobacterium avium subsp. paratuberculosis. The antigen-coated beads were incubated with serum samples of JD-positive or negative serum samples and then with a fluorescently-labeled secondary antibody (SAB). To confirm binding of serum antibodies to the antigen, the beads were subjected to flow cytometric analysis. Different conditions (dilutions of serum and SAB, types of SAB, and types of magnetic beads) were optimized for a great degree of differentiation between the JD-negative and JD-positive samples. Using the optimized conditions, we tested a well-classified set of 155 serum samples from JD negative and JD-positive cattle by using the bead-based flow cytometric assay. Of 105 JD-positive samples, 63 samples (60%) showed higher antibody binding levels than a cut-off value determined by using antibody binding levels of JD-negative samples. In contrast, only 43-49 JD-positive samples showed higher antibody binding levels than the cut-off value when the samples were tested by commercially-available immunoassays. Microfluidic assays were performed by magnetically immobilizing a number of beads within a microchannel of a glass microchip and detecting antibody on the collected beads by laser-induced fluorescence. Antigen-coated magnetic beads treated with bovine serum sample and fluorescently-labeled SAB were loaded into a microchannel to measure the fluorescence (reflecting level of antibody binding) on the beads in the microfluidic system. When the results of five bovine serum samples obtained with the system were compared to those obtained with the flow cytometer, a high level of correlation (linear regression, r2 = 0.994) was observed. In a further experiment, we magnetically immobilized antigen-coated beads in a microchannel, reacted the beads with serum and SAB in the channel, and detected antibody binding to the beads in the microfluidic system. A strong antibody binding in JD-positive serum was detected, whereas there was only negligible binding in negative control experiments. Our data suggest that the bead-based microfluidic system may form a basis for development of an on-site serodiagnosis of JD. Key Words: Mycobacterium avium ssp. paratuberculosis, Johne s disease, microfluidics, lab-on-a-chip.

Wadhwa, Ashutosh [University of Tennessee, Center for Wildlife Health, Department of Forestry; Foote, Robert [ORNL; Shaw, Robert W [ORNL; Eda, Shigetoshi [ORNL

2012-01-01

408

Motivating Blood Donors to Recruit New Donors: Experimental Evaluation of an Evidence-Based Behavior Change Intervention  

Microsoft Academic Search

Objective: A sustainable, evidence-based intervention to motivate current blood donors to recruit new donors was evaluated using a quasi-experimental, in-service trial at three donation centers. Design: Participating blood donors in three conditions (N = 734), received (1) an evidence-based leaflet designed to enhance recruitment motivation and five postcards facilitating recruitment and donor registration, (2) five postcards alone, or (3) no

Karin P. H. Lemmens; Robert A. C. Ruiter; Charles Abraham; Ingrid J. T. Veldhuizen; Herman P. Schaalma

2010-01-01

409

Donors' attitudes towards body donation for dissection  

Microsoft Academic Search

SummaryWe report a survey in the UK of potential whole-body donors for dissection. 218 people (age range 19-97 years) answered a postal questionnaire, giving information about themselves, their reasons for donation, attitudes towards the dead body, funeral preferences and medical giving and receiving. In addition to altruism, motives included the wish to avoid funeral ceremonies, to avoid waste, and in

R Richardson; B Hurwitz

1995-01-01

410

Adoptive Immunotherapy in Chimeras with Donor Lymphocytes  

Microsoft Academic Search

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

2003-01-01

411

Structures of Thermal Double Donors in Silicon  

Microsoft Academic Search

Accurate total-energy calculations are used to study the structures and formation energies of oxygen chains as models for thermal double donors (TDD's) in Si. We find that the first three TDD's (TDD0-TDD2) consist of one four-member ring, with one or two adjacent interstitial O atoms. These metastable TDD's form bistable negative-U systems with the corresponding stable, electrically inactive staggered structures.

M. Pesola; Young Joo Lee; J. von Boehm; M. Kaukonen; R. M. Nieminen

2000-01-01

412

HTLV-1/2 seroprevalence and coinfection rate in Brazilian first-time blood donors: an 11-year follow-up.  

PubMed

The seroprevalence and geographic distribution of HTLV-1/2 among blood donors are extremely important to transfusion services. We evaluated the seroprevalence of HTLV-1/2 infection among first-time blood donor candidates in Ribeirão Preto city and region. From January 2000 to December 2010, 1,038,489 blood donations were obtained and 301,470 were first-time blood donations. All samples were screened with serological tests for HTLV-1/2 using enzyme immunoassay (EIA). In addition, the frequency of coinfection with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), Chagas disease (CD) and syphilis was also determined. In-house PCR was used as confirmatory test for HTLV-1/2. A total of 296 (0.1%) first-time donors were serologically reactive for HTLV-1/2. Confirmatory PCR of 63 samples showed that 28 were HTLV-1 positive, 13 HTLV-2 positive, 19 negative and three indeterminate. Regarding HTLV coinfection rates, the most prevalent was with HBV (51.3%) and HCV (35.9%), but coinfection with HIV, CD and syphilis was also detected. The real number of HTLV-infected individual and coinfection rate in the population is underestimated and epidemiological studies like ours are very informative. PMID:22634882

Pinto, Mariana Tomazini; Rodrigues, Evandra Strazza; Malta, Tathiane Maistro; Azevedo, Rochele; Takayanagui, Osvaldo Massaiti; Valente, Vanderléia Bárbaro; Ubiali, Eugênia Maria Amorim; Covas, Dimas Tadeu; Kashima, Simone

2012-01-01

413

Changes in donor apheresis in Japan.  

PubMed

Donor apheresis has played an important role in the Japanese blood program. Donor plasmapheresis was introduced to increase source plasma in 1986 and accounted for 20.8% of all donations in 1995. The total volume of source plasma increased from 104 x 10(3) L in 1989 to 636 x 10(3) L in 1994, and the rate of self-sufficience of factor VIII reached 100% in 1994 (excluding recombinant products). This rate had been below 10% in 1991. The supply of platelet products has increased rapidly in Japan and reached 7.19 million units in 1995. The number of platelet products obtained with the apheresis procedure accounted for 99.99% in all supplied products in the Hokkaido Red Cross Blood Center. Thus, it can be seen that platelet apheresis has played an important role in securing a sufficiency of the products. Another advantage of platelet apheresis is the reduction of residual leukocytes in the products, which helps to avoid donor antigen exposure and prevent febrile nonhemolytic reaction. The technique of apheresis has been applied in cancer therapy. Peripheral blood stem cell (PBSC) transplantation has been performed not only in autologous but also allogeneic settings instead of bone marrow transplantation. In the authors' experience, sufficient numbers of progenitor cells could be collected in 85.7% of patients within 2 leukaphereses; thus, apheresis will become more important in this field. PMID:10225723

Sekiguchi, S; Sato, N; Yamamoto, S

1997-11-01

414

Nitric oxide donors for cardiovascular implant applications.  

PubMed

In an era of increased cardiovascular disease burden in the ageing population, there is great demand for devices that come in to contact with the blood such as heart valves, stents, and bypass grafts that offer life saving treatments. Nitric oxide (NO) elution from healthy endothelial tissue that lines the vessels maintains haemostasis throughout the vasculature. Surgical devices that release NO are desirable treatment options and N-diazeniumdiolates and S-nitrosothiols are recognized as preferred donor molecules. There is a keen interest to investigate newer methods by which NO donors can be retained within biomaterials so that their release and kinetic profiles can be optimized. A range of polymeric scaffolds incorporating microparticles and nanomaterials are presenting solutions to current challenges, and have been investigated in a range of clinical applications. This review outlines the application of NO donors for cardiovascular therapy using biomaterials that release NO locally to prevent thrombosis and intimal hyperplasia (IH) and enhance endothelialization in the fabrication of next generation cardiovascular device technology. PMID:23136136

Naghavi, Noora; de Mel, Achala; Alavijeh, Omid Sadeghi; Cousins, Brian G; Seifalian, Alexander M

2013-01-14

415

Experimental hypersensitivity pneumonitis: influence of donor sensitization.  

PubMed

Experimental hypersensitivity pneumonitis (EHP) can be transferred to strain 2 guinea pigs by lymphoblasts from lymph node cells from sensitized guinea pigs cultured in vitro with antigen. We sought to examine the relationship between characteristics of the donor animal and development of competence to transfer EHP. We also compared cell populations that were capable and incapable of transfer using flow cytometry and fluorescein conjugated anti-Ig to determine cell size and surface IgG + (SIg +: surface immunoglobulin-positive) cells. Lymph node cells from donor animals were cultured with a soluble extract of Micropolyspora faeni (10 micrograms/ml) for 72 hours; blasts were then isolated and transferred intravenously to syngeneic recipients. Control recipients received an equal volume of medium. Four groups of donors were used: animals systemically sensitized with Freund's adjuvant and M. faeni and challenged with two, four, or eight weekly intratracheal injections of M. faeni (2-, 4-, and 8-week group); and animals sensitized with Freund's adjuvant and normal saline and challenged with two weekly intratracheal injections of normal saline (NS group). Recipients were challenged intratracheally with M. faeni 48 hours after the cell transfer and killed 4 days thereafter. Randomly selected microscopic fields of the lung (250/animal) were judged to be normal or abnormal without knowledge of treatment. All animals were maintained in high efficiency particulate accumulator-filtered air. There was a low level of pulmonary response to an intratracheal challenge of M. faeni in animals that received media.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2341765

Schuyler, M; Gott, K; Shopp, G; Crooks, L

1990-05-01

416

Homograft valve durability: host or donor influence?  

PubMed

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 months, and subjected to immunocytochemistry, tissue culture, and karyotyping. The leaflet bases exhibited normal morphology with an intact endothelium. The distal one-third of the leaflets was devoid of fibroblasts from the leaflet bases showed them to be of host origin. This homograft seems to have been implanted with an intact ground substance which allowed for host cell repopulation of the inner one-third of the leaflets. Perhaps donor cell viability in itself is not as important to durability as is preservation of the leaflet ground substance, but rather the presence of viable cells may be an index of the structural integrity of the collagen and elastic matrix. PMID:2354984

Gonzalez-Lavin, L; Spotnitz, A J; Mackenzie, J W; Gu, J; Gadi, I K; Gullo, J; Boyd, C; Graf, D

1990-01-01

417

Low prevalence of HCV, HIV, and HTLV-I/II infection markers in northwestern Greece: results of a 3-year prospective donor study (1995-1997).  

PubMed

Background: The risk of infection with transfusion-transmitted viruses has been reduced remarkably. A zero-risk blood supply, however, remains a popular goal. A 3-year prospective donor study was conducted in the Epirus region of Greece to determine the prevalence of human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV), hepatitis B virus, and hepatitis C virus (HCV). Herein, we report the prevalence of HIV, HTLV, and HCV infection markers in this area. Methodology: Between January 1, 1995 and December 31, 1997, 6696 donors were investigated for the presence of anti-HIV, anti-HTLV, and anti-HCV antibodies using standard enzyme immunoassays (EIA). Every sample with anti-HCV reactivity by third-generation EIA was further investigated using a third-generation recombinant immunoblot assay (RIBA 3.0) and HCV-RNA by a combination of polymerase chain reaction (PCR) and DNA EIA. Results: None of the donors tested positive for anti-HIV or anti-HTLV antibodies. In contrast, anti-HCV was detected in 41 donors (0.61%). Using a RIBA 3.0 test, eight donors tested positive and eight had indeterminate results, while 25 tested negative. Seven of the eight donors with both EIA and RIBA 3.0 reactivity had increased levels of aminotransferases and detectable serum HCV-RNA. The remaining 34 donors had repeatedly normal aminotransferases and three times negative HCV-RNA. Liver biopsy was performed in anti-HCV/HCV-RNA-positive donors (7/41). The lesions were compatible with chronic hepatitis C in all of them. Conclusion: A zero prevalence of HIV and HTLV infection markers was found. Although the number of annual donations in this study was relatively low, the negative data for HIV and HTLV clearly indicate that rates of these infections are low in our region and that infected donors will be seen infrequently. HCV infection in blood donors remains very low in our region and is similar to the data reported in other industrialized countries. In fact, the prevalence of definite HCV infection seems to be very low (7/6696; 0.1%). However, a significant proportion of anti-HCV-reactive donors by third-generation EIA (33/41) had indeterminate or negative results by the RIBA 3.0. The latter donors were repeatedly negative for HCV-RNA. This finding may indicate that some donors tested false-positive for anti-HCV, although the possibility of true HCV infection contracted in the distant past cannot be excluded. In our opinion, close attention to mandatory principles of transfusion medicine, along with the screening of plasma donors using nucleic acid amplification technology, are the only methods that can further ensure the safety of our blood supply. PMID:12554009

Zervou, E K.; Boumba, D S.; Liaskos, Ch; Georgiadou, S; Tsianos, E V.; Dalekos, G N.

2003-02-01

418

Novel solution-phase immunoassays for molecular analysis of tumor markers.  

PubMed

at 3 x 10(9) M(-1) and a step-wise binding process with PSA-free MAB. Thus, this solution-phase quantitative ECL immunoassay allowed measurement of the affinity of serum PSAs with their MABs and screening of PSAs based upon their affinity to MABs. Unlike other immunoassays, this immunoassay demonstrated one-step rapid analysis while simultaneously eliminating immobilization, separation and washing steps and detected PSA at a level of 1.7 pg mL(-1), which is 1000-fold more sensitive than current PSA immunoassays. Furthermore, single-molecule (SM) phosphorescence microscopy was developed to detect single serum PSA-free and PSA-complex molecules in solution with no use of antibody showing that PSA-free molecules diffused faster than PSA-complex molecules in solution. This finding is consistent with ECL measurements and implies the possibility of screening individual analytes in a complex mixture using their distinct SM diffusion distance. This is the first report describing the detection of single protein molecules labeled with a metal-complex using phosphorescence microscopy and also the screening of serum tumor markers using ECL and SM phosphorescence solution-phase assays. PMID:11534594

Xu, X H; Jeffers, R B; Gao, J; Logan, B

2001-08-01

419

Diagnosis of Oropouche Virus Infection Using a Recombinant Nucleocapsid Protein-Based Enzyme Immunoassay  

Microsoft Academic Search

Oropouche (ORO) virus is an emerging infectious agent that has caused numerous outbreaks of an acute febrile (dengue-like) illness among humans in Brazil, Peru, and Panama. Diagnosis of ORO virus infection is based mainly on serology. Two different antigens, hamster serum antigen (HSA) and Vero cell lysate antigen (VCLA), are currently used in enzyme immunoassays (EIAs) in Brazil and Peru,

MOHAMMAD F. SAEED; MARCIO NUNES; PEDRO F. VASCONCELOS; ROBERT E. SHOPE; ROBERT B. TESH; ALAN D. T. BARRETT

2001-01-01

420

Automated digital microfluidic platform for magnetic-particle-based immunoassays with optimization by design of experiments.  

PubMed

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

2013-10-15

421

Development of a Nanoparticle-Labeled Microfluidic Immunoassay for Detection of Pathogenic Microorganisms  

PubMed Central

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.

2005-01-01

422

IMMUNOASSAY METHOD FOR THE DETERMINATION OF PENTACHLOROPHENOL IN SOIL AND SEDIMENT  

EPA Science Inventory

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...

423

False-Positive Results of Enzyme Immunoassays for Human Immunodeficiency Virus in Patients with Uncomplicated Malaria  

PubMed Central

Malaria may impact upon human immunodeficiency virus (HIV) test results. We evaluated two HIV enzyme immunoassays (EIAs) by testing 1,965 Ugandans with malaria. We found poor positive predictive values (53% and 76%), particularly with younger age. Combining EIAs eliminated false positives but missed 21% of true positives. Performance of HIV EIAs in malaria may be unsatisfactory.

Gasasira, Anne F.; Dorsey, Grant; Kamya, Moses R.; Havlir, Diane; Kiggundu, Moses; Rosenthal, Philip J.; Charlebois, Edwin D.

2006-01-01

424

Development of an electrochemical immunoassay for detection of gatifloxacin in swine urine*  

PubMed Central

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.

Yi, Jian; Meng, Meng; Liu, Zhong-qiu; Zhi, Jin-fang; Zhang, Yuan-yang; Xu, Jing; Wang, Ya-bin; Liu, Jin-ting; Xi, Ri-mo

2012-01-01

425

Quantitative determination of nuclear estrogen receptors by an enzyme immunoassay: applicability and caveats.  

PubMed

A method is presented with which approx. 95% of nuclear estrogen receptors appear to be extracted from MCF-7 cells. Since both nuclear isolation and nuclear estrogen receptor extraction take place in a single test tube with only vortex mixing, loss of nuclear material is minimized. The amount of nuclear estrogen receptors in the nuclear extract was determined by direct [3H]estradiol labeling of monolayer cultures and with a commercially available estrogen receptor immunoassay (ER-EIA) kit. Since the ER-EIA kit was designed and calibrated for quantitative determination of cytosolic estrogen receptor isolated in low ionic strength buffer, the applicability of the ER-EIA to quantitative determination of estrogen receptor content in high ionic strength nuclear extraction buffer was tested. A linear relationship exists between the amount of nuclear estrogen receptor detected by the immunoassay, the amount of receptor present in serial dilutions of the nuclear extract and the amount of nuclear estrogen receptor detected in cells by [3H]estradiol labeling of monolayer cultures, the absolute amount of nuclear estrogen receptors determined by the immunoassay consistently exceeded the amount of receptor detected by [3H]estradiol labeling. The possibility that the enzyme immunoassay must be properly calibrated for the specific conditions of the nuclear estrogen receptor assay is discussed. PMID:3050279

Kral, L G; Doherty, L M; Brooks, S C

1988-10-01

426

Superfund Innovative Technology Evaluation (SITE) Program Evaluation Report for Antox BTX Water Screen (BTX Immunoassay).  

National Technical Information Service (NTIS)

The results of a demonstration of a portable immunoassay for the detection of benzene, toluene, and xylene(s) (BTX) are described in the report. Seventy-nine field samples were obtained from monitoring wells at several sites with gasoline contaminated gro...

R. W. Gerlach R. J. White N. F. O'Leary J. M. Van Emon

1993-01-01