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Sample records for donor immunoassay cedia

  1. Comparison between the CEDIA and EMIT II immunoassays for the determination of benzodiazepines.

    PubMed

    Way, B A; Walton, K G; Koenig, J W; Eveland, B J; Scott, M G

    1998-03-01

    We evaluated a new, qualitative immunoassay for benzodiazepines in urine using CEDIA technology on the Hitachi 747 and compared its performance to an immunoassay using EMIT II methodology on the same instrument. A total of 500 urine samples received for routine drug screen analysis were prospectively examined for benzodiazepines by both methods. Samples producing positive results by either immunoassay method were analyzed by gas chromatography-mass spectrometry (GC-MS). Available medical records were reviewed for patients whose samples produced discrepant immunoassay results or that were positive in both immunoassays but negative by GC-MS. Samples that produced negative results in both immunoassays were not subjected to GC-MS analysis. Therefore, identification of an immunoassay result as a false negative only occurred when the sample produced a positive value in only one of the two immunoassays and was confirmed as positive by either GC-MS or medical record review. Following initial immunoassay screening and confirmation by GC-MS, a medical record review and reanalysis of GC-MS data was performed. After this in-depth analysis of the data, the CEDIA method produced 60 true-positives, 7 false positives and no false negatives. The EMIT II method produced 47 true positives, 1 fase positive and 13 false negatives. These differences appear to be due to the CEDIA assay being more sensitive for detection of lorazepam. PMID:9564553

  2. Comparison of LUCIO-direct ELISA with CEDIA immunoassay for 'zero tolerance' drug screening in urine as required by the German re-licensing guidelines.

    PubMed

    Agius, Ronald; Nadulski, Thomas; Kahl, Hans-Gerhard; Dufaux, Bertin

    2013-06-01

    The performance of the previously validated LUCIO()-Direct-enzyme linked immunosorbent assay (direct ELISA) screening tests according to forensic guidelines is compared to that of cloned enzyme donor immunoassays (CEDIA) test for drugs of abuse in urine as defined in the new re-licensing German medical and psychological assessment (MPA) guidelines. The MPA screening cut-offs correspond to 10?ng/ml 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH), 50?ng/ml amphetamine and designer amphetamines, 25?ng/ml morphine, codeine and dihydrocodeine, 30?ng/ml benzoylecgonine, 50?ng/ml methadone metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and metabolites of diazepam, oxazepam, bromazepam, alprazolam, flunitrazepam and lorazepam at 50?ng/ml. Average relative sensitivities and relative specificities were 99.7 % and 98.4 % for direct ELISA and 66 % and 91.4 % for CEDIA, respectively. PMID:23349145

  3. Optimization and validation of CEDIA drugs of abuse immunoassay tests in serum on Hitachi 912.

    PubMed

    Kirschbaum, Katrin M; Musshoff, Frank; Schmithausen, Ricarda; Stockhausen, Sarah; Madea, Burkhard

    2011-10-10

    Due to sensitive limits of detection of chromatographic methods and low limit values regarding the screening of drugs under the terms of impairment in safe driving (§ 24a StVG, Street Traffic Law in Germany), preliminary immunoassay (IA) tests should be able to detect also low concentrations of legal and illegal drugs in serum in forensic cases. False-negatives should be avoided, the rate of false-positive samples should be low due to cost and time. An optimization of IA cutoff values and a validation of the assay is required for each laboratory. In a retrospective study results for serum samples containing amphetamine, methylenedioxy derivatives, cannabinoids, benzodiazepines, cocaine (metabolites), methadone and opiates obtained with CEDIA drugs of abuse reagents on a Hitachi 912 autoanalyzer were compared with quantitative results of chromatographic methods (gas or liquid chromatography coupled with mass spectrometry (GC/MS or LC/MS)). Firstly sensitivity, specificity, positive and negative predictive values and overall misclassification rates were evaluated by contingency tables and compared to ROC-analyses and Youden-Indices. Secondly ideal cutoffs were statistically calculated on the basis of sensitivity and specificity as decisive statistical criteria with focus on a high sensitivity (low rates of false-negatives), i.e. using the Youden-Index. Immunoassay (IA) and confirmatory results were available for 3014 blood samples. Sensitivity was 90% or more for nearly all analytes: amphetamines (IA cutoff 9.5 ng/ml), methylenedioxy derivatives (IA cutoff 5.5 ng/ml), cannabinoids (IA cutoff 14.5 ng/ml), benzodiazepines (IA cutoff >0 ng/ml). Test of opiates showed a sensitivity of 86% for a IA cutoff value of >0 ng/ml. Values for specificity ranged between 33% (methadone, IA cutoff 10 ng/ml) and 90% (cocaine, IA cutoff 20 ng/ml). Lower cutoff values as recommended by ROC analyses were chosen for most tests to decrease the rate of false-negatives. Analyses enabled the definition of cutoff values with good values for sensitivity. Small rates of false-positives can be accepted in forensic cases. PMID:21775079

  4. Buprenorphine detection in urine using liquid chromatography-high-resolution mass spectrometry: comparison with cloned enzyme donor immunoassay (ThermoFisher) and homogeneous enzyme immunoassay (immunalysis).

    PubMed

    Belsey, Sarah L; Couchman, Lewis; Flanagan, Robert J

    2014-09-01

    A sensitive liquid chromatographic-high-resolution mass spectrometric (LC-HR-MS) assay for buprenorphine and its urinary metabolites has been developed that requires minimal sample preparation. The results obtained have been compared with those given by (i) cloned enzyme donor immunoassay (CEDIA) and (ii) homogeneous enzyme immunoassay (HEIA) in the analysis of patient urines submitted for buprenorphine analysis. Centrifuged urine (100 L) was diluted with internal standard solution (25 L) + LC eluent (875 L), and 50 L of the prepared sample were analyzed (Accucore Phenyl-Hexyl column). MS detection was in alternating positive and negative mode using heated electrospray ionization (ThermoFisher Q Exactive). Intra- and inter-assay accuracy and precision were 104-128 and <11%, respectively, at 5 g/L. Limits of detection were 1.3 g/L (buprenorphine, norbuprenorphine and buprenorphine glucuronide) and 2.5 g/L (norbuprenorphine glucuronide). Immunoassay sensitivity and selectivity were 97 and 100% (HEIA) and 99 and 84% (CEDIA), respectively, compared with LC-HR-MS. In 120 patient urines, norbuprenorphine glucuronide was easily the most abundant analyte except when adulteration with buprenorphine had occurred. The median immunoreactive buprenorphine species present (unhydrolysed urine) were 7.5 and 13% for HEIA and CEDIA, respectively. However, codeine, dihydrocodeine, morphine and morphine-3-glucuronide did not interfere in the HEIA assay. PMID:24925983

  5. Urinary buprenorphine concentrations in patients treated with suboxone as determined by liquid chromatography-mass spectrometry and CEDIA immunoassay.

    PubMed

    Hull, Mindy J; Bierer, Michael F; Griggs, David A; Long, William H; Nixon, Andrea L; Flood, James G

    2008-09-01

    We report on the utility of urine total buprenorphine, total norbuprenorphine, and creatinine concentrations in patients treated with Suboxone (a formulation containing buprenorphine and naloxone), used increasingly for the maintenance or detoxification of patients dependent on opiates such as heroin or oxycodone. Patients received 8-24 mg/day buprenorphine. Two-hundred sixteen urine samples from 70 patients were analyzed for both total buprenorphine and total norbuprenorphine by liquid chromatography-mass spectrometry (LC-MS-MS). Buprenorphine concentrations in all 176 samples judged to be unadulterated averaged 164 ng/mL, with a standard deviation (SD) of 198 ng/mL. Nine samples (4.2%) had metabolite-parent drug ratios < 0.02, and 33 (15.3%) had no detectable buprenorphine. The metabolite/parent drug ratio in 166 samples had a range of 0.07-23.0 (mean = 4.52; SD = 3.97). Fifteen of 96 available urine samples (16.7%) had creatinine less than 20 mg/dL. We also found sample adulteration in 7 (7.3%) available samples. Using a 5 ng/mL urine buprenorphine cutoff, the sensitivity and specificity of the Microgenics homogeneous enzyme immunoassay versus LC-MS-MS were 100% and 87.5%, respectively. The 5 ng/mL cutoff Microgenics CEDIA buprenorphine assay results agreed analytically with LC-MS-MS in 97.9% of samples. PMID:18713521

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

    PubMed

    Birch, M A; Couchman, L; Pietromartire, S; Karna, T; Paton, C; McAllister, R; Marsh, A; Flanagan, R J

    2013-05-01

    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 g/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

  7. Cross-reactivity of the CEDIA buprenorphine assay in drugs-of-abuse screening: influence of dose and metabolites of opioids

    PubMed Central

    Berg, Jon Andsnes; Schjøtt, Jan; Fossan, Kjell O; Riedel, Bettina

    2015-01-01

    Purpose The cloned enzyme donor immunoassay (CEDIA) for buprenorphine is applied for both urine drugs-of-abuse screening and compliance monitoring. Sensitivity, specificity, and optimal cutoff of this assay have differed between studies. This may indicate that cross-reactivity has to be taken into account during assay evaluation. We therefore investigated the performance of the CEDIA buprenorphine assay for use in our patient population and explored the impact of cross-reactivity on assay accuracy. Methods The CEDIA buprenorphine assay and high-performance liquid chromatography–tandem mass spectrometry were employed to analyze drugs-of-abuse in urine samples from a healthy drug-naïve male volunteer after intake of two tablets of a prescription drug containing 400 mg paracetamol +30 mg codeine phosphate, and in urine samples (n=2,272) from drug-addicted patients. Receiver operating characteristic analyses were performed to express the diagnostic accuracy of the CEDIA buprenorphine assay. Results CEDIA buprenorphine was positive in one urine sample from the drug-naïve person after intake of the prescription drug. Twenty-five (1.1%) of the patient urine samples were positive for buprenorphine by CEDIA, but negative by high-performance liquid chromatography–tandem mass spectrometry. Codeine, morphine, and their respective metabolites were prevalent in samples that were false positive for buprenorphine. The specificity of the CEDIA buprenorphine assay increased to 99.7% when the cutoff was increased from 5 ng/mL to 10 ng/mL. Conclusion Intake of a therapeutic dose of codeine can yield a false-positive CEDIA buprenorphine result. Additive effects from metabolites of codeine contribute to cross-reactivity in concentrations much lower than listed in the manufacturer’s cross-reactivity guide. Raising the cutoff from 5 ng/mL to 10 ng/mL increased the diagnostic accuracy. Clinicians should be informed about the risk of false-positive results with the CEDIA buprenorphine assay. PMID:26604854

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

    PubMed

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

    2014-05-01

    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. PMID:24665024

  9. Immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassays are analytical methods that employ antibodies or molecules derived from antibodies for the essential binding reactions. The choice of immunoassay system for food safety analysis depends on the analyte, the matrix, and the requirements of the analysis (speed, throughput, sensitivity, spe...

  10. Immunoassays

    NASA Astrophysics Data System (ADS)

    Hsieh, Y.-H. Peggy

    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.

  11. Comparison of performance of two Treponema pallidum automated chemiluminescent immunoassays in blood donors.

    PubMed

    Sommese, Linda; Sabia, Chiara; Esposito, Antonella; Iannone, Carmela; Montesano, Maria Lourdes; Napoli, Claudio

    2016-06-01

    The recrudescence of syphilis is leading to the development of new serological tests. The goal of this study was to compare the performance of the more recent Elecsys Syphilis assay, the Electro Chemiluminescence Immunoassay (ECLIA), with the former Architect Syphilis TP assay, the Chemiluminescent Microparticle Immunoassay (CMIA), for the detection of antibodies against Treponema pallidum in blood donors. Serum samples of 5543 voluntary blood donors were screened in parallel with two tests. All repeatedly reactive (RR) samples by one or both assays were further analysed for confirmation by immmunoblot INNO-LIA and TPHA. Of 32 RR samples by CMIA, 21 were confirmed positive; of 21 RR samples by ECLIA, 20 were confirmed positive. The sensitivities of CMIA and ECLIA were 100% and 95.24% (95% CI = 85.71-100), respectively, not significant (p > 0.05). The specificity and predictive positive value (PPV) of CMIA were 99.86% (95% CI = 99.74-99.94) and 72.41%, respectively, while the specificity and PPV of ECLIA were both 100%, being statistically significant (p = 0.01 for both). The overall agreement was 99.80% and the Cohen's kappa coefficients was 0.79. In conclusion, the recent Elecsys Syphilis assay could represent another reliable assay for blood donor screening. PMID:27030921

  12. False-positive amphetamine/ecstasy (MDMA/3,4-methylenedioxymethamphetamine) (CEDIA) and ecstasy (MDMA/3,4-methylenedioxymethamphetamine) (DRI) test results with fenofibrate.

    PubMed

    Kaplan, Yusuf Cem; Erol, Almla; Karadaş, Barş

    2012-10-01

    This case report describes a false-positive amphetamine/ecstasy [3,4-methylenedioxymethamphetamine (MDMA)] and ecstasy (MDMA) screen after therapeutic use of antihyperlipidemic drug, fenofibrate. A 60-year-old male patient was admitted to inpatient psychiatry unit with the diagnosis of alcohol dependency. He was prescribed diazepam 30 mg/day, thiamine 300 mg/day, and naltrexone 50 mg/day. He had also been using fenofibrate 267 mg/day for 3 years for hyperlipidemia and trazodone 100 mg/day for 5 months for insomnia. On routine, urine drugs-of-abuse screening amphetamine/MDMA (CEDIA) test was positive for 4 different occasions and MDMA (DRI) test was positive on 5 different occasions. Gas chromatography/mass spectrometry confirmation of the first positive 3 samples were negative for amphetamine and MDMA. After discontinuation of fenofibrate, amphetamine/MDMA, and MDMA immunoassay results turned out to be negative. Caution should be given to interpretation of amphetamine/MDMA (CEDIA) and MDMA (DRI) tests in patients taking fenofibrate. Specific confirmation with a suitable method should be used to prevent erroneous interpretations. PMID:22972534

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

    PubMed

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

    2006-04-01

    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

  14. In Situ Generation of Electron Donor to Assist Signal Amplification on Porphyrin-Sensitized Titanium Dioxide Nanostructures for Ultrasensitive Photoelectrochemical Immunoassay.

    PubMed

    Shu, Jian; Qiu, Zhenli; Zhuang, Junyang; Xu, Mingdi; Tang, Dianping

    2015-10-28

    An ultrasensitive photoelectrochemical (PEC) immunoassay protocol for quantitative detection of low-abundant proteins at a low potential was designed by utilizing porphyrin-sensitized titanium dioxide (TiO2) nanostructures. Experimental results demonstrated that the water-soluble 5,10,15,20-tetra(4-sulfophenyl)-21H,23H-porphyrin (TSPP) could be bound onto titanium dioxide via the sulfonic group. TSPP-sensitized TiO2 nanostructures exhibited better photoelectrochemical responses and stability in comparison with TiO2 nanoparticles alone under continuous illumination. Using carcinoembryonic antigen (CEA) as a model analyte, a typical PEC immunosensor by using TSPP-TiO2 as the affinity support of anti-CEA capture antibody (Ab1) to facilitate the improvement of photocurrent response was developed. Bioconjugates of secondary antibody and glucose oxidase with gold nanoparticles (Ab2/GOx-AuNPs) was introduced by an antigen-antibody immunoreaction. AuNP acted as a powerful scaffold to bind with bioactive molecules, while GOx catalyzed glucose to in situ generate hydrogen peroxide (H2O2). The generated H2O2 as a sacrificial electron donor could be oxidized by the photogenerated holes to assist the signal amplification at a low potential under light excitation, thus eliminating interference from other species coexisting in the samples. Under optimal conditions, the PEC immunosensor showed a good linear relationship ranging from 0.02 to 40 ng mL(-1) with a low detection limit of 6 pg mL(-1) CEA. The precision, reproducibility, and specificity were acceptable. In addition, the method accuracy was also evaluated for quantitatively monitoring human serum samples, giving results matching with the referenced CEA ELISA kit. PMID:26451956

  15. Immunoassay techniques.

    PubMed

    Wheeler, Michael J

    2013-01-01

    No other development has had such a major impact on the measurement of hormones as immunoassay. Reagents and assay kits can now be bought commercially but not for the more esoteric or new hormones. This chapter explains the basics of the immunoassay reaction and gives simple methods for immunoassays and immunometric assays and for the production of reagents for both antigenic and hapten hormones. Alternative methods are given for the preparation of labeled hormones as well as several possible separation procedures. The methods described here have been previously used in a wide range of assays and have stood the test of time. They will allow the production of usable immunoassays in a relatively short period of time. PMID:23996355

  16. Determination of designer drug cross-reactivity on five commercial immunoassay screening kits.

    PubMed

    Regester, Laura E; Chmiel, Jeffrey D; Holler, Justin M; Vorce, Shawn P; Levine, Barry; Bosy, Thomas Z

    2015-03-01

    The detection of new designer drugs is often a difficult issue in forensic urine drug testing as immunoassays are the primary screening methodology for drugs of abuse in many of these laboratories. Cross-reactivity of compounds with immunoassay kits can either aid or complicate the detection of a variety of drug and drug metabolites. For instance, emerging designer drugs that share structural similarities to amphetamines and phencyclidine (PCP) have the potential to cross-react with assays designed to detect these compounds. This study evaluates the cross-reactivity of five commercially available immunoassay reagent kits for 94 designer drugs on a Roche/Hitachi Modular P automated screening instrument. The compounds used in this study are grouped by structural class as follows: 2,5-dimethoxyamphetamines, 2C (2,5-dimethoxyphenethylamines), β-keto amphetamines, substituted amphetamines, piperazines, α-pyrrolidinopropiophenones, tryptamines and PCP analogs. A drug concentration of 100 µg/mL was used to determine cross-reactivity for each assay and resulted in the following positive rates: Microgenics DRI(®) Ecstasy enzyme assay (19%), Microgenics DRI(®) Phencyclidine enzyme assay (20%), Lin-Zhi Methamphetamine enzyme immunoassay (39%), Siemens/Syva(®) EMIT(®)II Plus Amphetamines assay (43%) and CEDIA(®) DAU Amphetamine/Ecstasy assay (57%). Of the 94 designer drugs tested, 14% produced a negative response for all five kits. No designer drug used in this study generated a positive result for all five immunoassay kits. PMID:25492523

  17. Role of signal-to-cut-off ratios of anti-hepatitis C virus antibody by enzyme immunoassays along with ID-NAT for screening of whole blood donors in India

    PubMed Central

    Arora, Satyam; Doda, Veena

    2016-01-01

    Background: The use of elevated signal-to-cut off ratios (S/CO) as an alternate to further supplemental testing (i.e., RIBA) has been included in the guidelines provided by the Centres for Disease Control and Prevention for HCV diagnostic purposes since 2003. With availability of screening by NAT and non availability of RIBA, further confirmation of HCV infection has been possible at the molecular level (RNA). Aims: To study the role of S/CO ratios of anti hepatitis C virus antibody detection by enzyme immunoassays (EIA) along with ID-NAT for screening of whole blood donors. Methods: In this study we reviewed the donor screening status for anti HCV from January 2013 to May 2014. All the donations were screened for anti HCV with fourth generation ELISA (BioRad Monolisa Ag-Ab Ultra) as well as with ID NAT (Procleix Ultrio). The S/CO ratio of all the anti-HCV reactive samples were analysed for their presence of HCV RNA. Results: On screening 21,115 donors for HCV, 83 donors (0.39%) were found reactive on pilot tube and repeat plasma bag testing (S/Co ratio ≥1) by ELISA. 41 donors were HCV RNA reactive with ID-NAT. 4 samples out of 41 were NAT yields and 37 were concordant reactive with ELISA. The S/Co ratio of anti-HCV reactive samples ranged from 0.9-11.1 [mean = 5.1; SD ± 2.9] whereas S/Co ratio of anti HCV and NAT reactive samples (concordant positives) ranged from 4.1-11.1 [mean 7.3]. In our analysis we found that S/CO ratio of 4 showed positive predictive value (PPV) and sensitivity of 100%. Summary/Conclusions: Our study showed that S/CO of 4 for anti HCV on ELISA would have maximum positive predictive value of having donor with HCV RNA. S/CO ratio of 4 is very close to 3.8 which was the CDC guideline. The presence of anti-HCV does not distinguish between current or past infections but a confirmed anti-HCV-positive result indicates the need for counseling and medical evaluation for HCV infection. PMID:27011676

  18. Effects of Stealth adulterant on immunoassay testing for drugs of abuse.

    PubMed

    Cody, J T; Valtier, S

    2001-09-01

    Stealth is an adulterant advertised as being undetectable by adulteration tests. It has been described as peroxidase and peroxide, which, when added to urine samples, are intended to prevent a positive drug test. Characterization of the effect of Stealth on urine samples and immunoassay results was undertaken to assist in detection of this adulterant. Stealth was added to a number of urine matrices, and various parameters were evaluated including pH, specific gravity, color, creatinine, chloride, urea, blood, glucose, and nitrite. Samples were spiked with THC acid metabolite, benzoylecgonine, morphine, secobarbital, PCP, amphetamine, and lysergic acid diethylamide (LSD) then tested by Roche OnLine and Microgenics CEDIA immunoassay reagents. Results of these analyses showed Stealth did not cause the urine sample to exceed any of the monitored parameters including those routinely used in drug-testing laboratories that would indicate adulteration of a sample. It did, however, cause samples positive for the marijuana metabolite (11-nor-delta9-tetrahydrocannibinol-9-carboxylic acid), LSD, and opiate (morphine) at 125-150% of cutoff to screen negative by immunoassay. Adulterating an authentic positive sample provided by a marijuana user caused that sample to screen negative using these immunoassay reagents as well. PMID:11550822

  19. 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

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

    1996-01-01

    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. PMID:8862583

  20. Immunoassays in Biotechnology

    EPA Science Inventory

    Immunoassays have broad applications for a wide variety of important biological compounds and environmental contaminants. Immunoassays can detect the presence of an antigen in the human body, a pollutant in the environment, or a critical antibody in a patient’s serum to develop a...

  1. Immunoassays in Biotechnology

    EPA Science Inventory

    Immunoassays have broad applications for a wide variety of important biological compounds and environmental contaminants. Immunoassays can detect the presence of an antigen in the human body, a pollutant in the environment, or a critical antibody in a patients serum to develop a...

  2. Universal phosphorescence immunoassay

    NASA Astrophysics Data System (ADS)

    Mantrova, Ekaterina Y.; Demcheva, Marina V.; Savitsky, Alexander P.; Ponomarev, Gely V.

    1993-05-01

    Pd-coproporphyrin I (Pd-CP) has optimum phosphorescence characteristics for application in immunoassay. The aim of this study is to work out a universal phosphorescence immunoassay method (UniPhIA) using monoclonal antibodies to Pd-CP and conjugates of various proteins with Pd-CP for detection of insulin. Pd-CP and monoclonal antibodies obtained allow a convenient method for determination of various antigens to be developed, which combines the universal character of the amplified enzyme-linked immunosorbent assay (a-ELISA) with a high sensitivity and the simplicity of the time-resolved phosphorescence immunoassay.

  3. 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

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

    2012-12-18

    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

  4. Hydrogel nanoparticle based immunoassay

    DOEpatents

    Liotta, Lance A; Luchini, Alessandra; Petricoin, Emanuel F; Espina, Virginia

    2015-04-21

    An immunoassay device incorporating porous polymeric capture nanoparticles within either the sample collection vessel or pre-impregnated into a porous substratum within fluid flow path of the analytical device is presented. This incorporation of capture particles within the immunoassay device improves sensitivity while removing the requirement for pre-processing of samples prior to loading the immunoassay device. A preferred embodiment is coreshell bait containing capture nanoparticles which perform three functions in one step, in solution: a) molecular size sieving, b) target analyte sequestration and concentration, and c) protection from degradation. The polymeric matrix of the capture particles may be made of co-polymeric materials having a structural monomer and an affinity monomer, the affinity monomer having properties that attract the analyte to the capture particle. This device is useful for point of care diagnostic assays for biomedical applications and as field deployable assays for environmental, pathogen and chemical or biological threat identification.

  5. Mass spectrometric immunoassay

    DOEpatents

    Nelson, Randall W.; Williams, Peter; Krone, Jennifer Reeve

    2005-12-13

    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.

  6. Mass spectrometric immunoassay

    DOEpatents

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2007-12-04

    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.

  7. Mass spectrometric immunoassay

    DOEpatents

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2013-07-16

    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.

  8. IMMUNOASSAY HUMAN EXPOSURE STUDIES

    EPA Science Inventory

    The Human Exposure Research Branch has developed several enzyme-linked immunosorbent assay (ELISA) methods to support human exposure assessment studies. Immunoassays to detect low levels (<10 ng/mL) of chlorpyrifos in food, track-in dirt and house dust have been applied to sam...

  9. Immunoassays for pesticide monitoring

    NASA Astrophysics Data System (ADS)

    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

    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.

  10. Lateral Flow Immunoassay.

    PubMed

    Ching, Kathryn H

    2015-01-01

    Lateral flow immunoassays (LFIAs) are a staple in the field of rapid diagnostics. These small handheld devices require no specialized training or equipment to operate, and generate a result within minutes of sample application. They are an ideal format for many types of home test kits, for emergency responders and for food manufacturers and producers looking for a quick evaluation of a given sample. LFIAs rely on high quality monoclonal antibodies that recognize the analyte of interest. As monoclonal antibody technology becomes more accessible to smaller laboratories, there has been increased interest in developing LFIA prototypes for potential commercial manufacture. In this chapter, the basics of designing and building an LFIA prototype are described. PMID:26160571

  11. Morphological resonances for multicomponent immunoassays

    NASA Astrophysics Data System (ADS)

    Whitten, W. B.; Shapiro, M. J.; Ramsey, J. M.; Bronk, B. V.

    1995-06-01

    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.

  12. Multiplexed single molecule immunoassays.

    PubMed

    Rissin, David M; Kan, Cheuk W; Song, Linan; Rivnak, Andrew J; Fishburn, Matthew W; Shao, Qichao; Piech, Tomasz; Ferrell, Evan P; Meyer, Raymond E; Campbell, Todd G; Fournier, David R; Duffy, David C

    2013-08-01

    We have developed a method that enables the multiplexed detection of proteins based on counting single molecules. Paramagnetic beads were labeled with fluorescent dyes to create optically distinct subpopulations of beads, and antibodies to specific proteins were then immobilized to individual subpopulations. Mixtures of subpopulations of beads were then incubated with a sample, and specific proteins were captured on their specific beads; these proteins were then labeled with enzymes via immunocomplex formation. The beads were suspended in enzyme substrate, loaded into arrays of femtoliter wells--or Single Molecule Arrays (Simoa)--that were integrated into a microfluidic device (the Simoa disc). The wells were then sealed with oil, and imaged fluorescently to determine: a) the location and subpopulation identity of individual beads in the femtoliter wells, and b) the presence or absence of a single enzyme associated with each bead. The images were analyzed to determine the average enzyme per bead (AEB) for each bead subpopulation that provide a quantitative parameter for determining the concentration of each protein. We used this approach to simultaneously detect TNF-α, IL-6, IL-1α, and IL-1β in human plasma with single molecule resolution at subfemtomolar concentrations, i.e., 200- to 1000-fold more sensitive than current multiplexed immunoassays. The simultaneous, specific, and sensitive measurement of several proteins using multiplexed digital ELISA could enable more reliable diagnoses of disease. PMID:23719780

  13. Fluorescence fluctuation immunoassay.

    PubMed

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

    1983-01-01

    The homogeneous fluorescent immunoassay described above allows one to measure the brightness of fluorescently tagged carrier particles that are suspended in a background of free, unbound fluorescent sources. We have demonstrated the feasibility of our technique using a gentamicin competitive assay as well as idealized model systems. We have seen that the fluctuation-correlation method is able to discriminate against free background sources because each fluorescing particle in solution contributes to the correlation peak [Eq. (4)] with a weighting equal to the square of its respective intensity. Hence, a few very bright sources contribute disproportionately to the "signal" relative to many weak ones. To take advantage of this property, one would therefore design an assay that uses relatively larger carrier particles, each of which is capable of binding on the order of 10(3) to 10(4) tagged antibodies or antigens. Unfortunately, the nonlinear dependence of the correlation peak on the brightness of the fluorescing species causes the technique to be perturbed by carrier particle aggregation; the apparent bound fluorescence intensity increases with the extent of aggregation. The latter may be an unavoidable consequence of performing assays using raw blood serum, for example. The ultimate usefulness of this method will depend on its sensitivity and speed when applied to "real" assays of clinical significance. These characteristics will be influenced by a number of technical details. Given our limited experience with the method thus far, it would appear that its principal drawback is its relatively slow speed. In order to decrease the time needed for a reliable measurement, one must average the random fluctuations in the fluorescent intensity to zero more quickly. In principle, this can be accomplished by decreasing the shot noise by collecting a larger fraction of the fluorescent light, and increasing the sampling rate. The method requires rather complicated instrumentation; it is by no means clear that this level of complexity is justified given the realistic level of sensitivity that will be obtained by this technique. PMID:6855625

  14. Use of aptamers in immunoassays.

    PubMed

    Nezlin, Roald

    2016-02-01

    Aptamers, short single-chain DNA or RNA oligonucleotides, react specifically with small molecules, as well as with proteins. Unlike antibodies, they may be obtained relatively easily. Aptamers are now widely employed in immunological studies and could replace antibodies in immunoassays. In this short review, methods for immobilizing aptamers on various insoluble materials (so-called apta-sorbents) are described. Recent findings on their use in the detection and isolation of immunoglobulins and their application in various immunoassays are also discussed. PMID:26774749

  15. Bioelectrochemical Immunoassay of Polychlorinated Biphenyl

    SciTech Connect

    Lin, Ying-Ying; Liu, Guodong; Wai, Chien M.; Lin, Yuehe

    2008-04-01

    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.

  16. Protein Adsorption in Microengraving Immunoassays

    PubMed Central

    Song, Qing

    2015-01-01

    Microengraving is a novel immunoassay forcharacterizing multiple protein secretions from single cells. During the immunoassay, characteristic diffusion and kinetic time scales τD and τK determine the time for molecular diffusion of proteins secreted from the activated single lymphocytes and subsequent binding onto the glass slide surface respectively. Our results demonstrate that molecular diffusion plays important roles in the early stage of protein adsorption dynamics which shifts to a kinetic controlled mechanism in the later stage. Similar dynamic pathways are observed for protein adsorption with significantly fast rates and rapid shifts in transport mechanisms when C0* is increased a hundred times from 0.313 to 31.3. Theoretical adsorption isotherms follow the trend of experimentally obtained data. Adsorption isotherms indicate that amount of proteins secreted from individual cells and subsequently captured on a clean glass slide surface increases monotonically with time. Our study directly validates that protein secretion rates can be quantified by the microengraving immunoassay. This will enable us to apply microengraving immunoassays to quantify secretion rates from 104–105 single cells in parallel, screen antigen-specific cells with the highest secretion rate for clonal expansion and quantitatively reveal cellular heterogeneity within a small cell sample. PMID:26501282

  17. Competitive Homogeneous Immunoassay for Rapid Serodiagnosis of Hantavirus Disease

    PubMed Central

    Rusanen, Juuso; Hepojoki, Jussi; Nurmi, Visa; Vaheri, Antti; Lundkvist, ke; Hedman, Klaus; Vapalahti, Olli

    2015-01-01

    In this study, we describe a competitive homogeneous immunoassay that makes use of Frster resonance energy transfer (FRET) in rapid detection of pathogen-specific antibodies. The assay principle is based on competition between a monoclonal antibody (MAb) and serum antibodies to a given antigen. In the assay, named competitive FRET immunoassay (CFRET-IA), the FRET signal is induced if MAb carrying a donor label binds to an acceptor-labeled antigen. Specific antibodies in serum compete for antigen binding, resulting in reduced FRET signal. The proof-of-principle for the assay was obtained using donor-labeled Puumala virus nucleocapsid protein (PUUV-N) and acceptor-labeled anti-PUUV-N MAb. The assay was evaluated by analyzing 329 clinical samples comprising 101 from individuals with acute PUUV infection, 42 from individuals with past infection, and 186 from individuals with PUUV-seronegative sera, and the results were compared to those of reference tests. The rapid serodiagnostic test we introduced herein performed with 100% sensitivity and 99% specificity for diagnosing acute hantavirus disease. PMID:25972427

  18. Scheme for the selection of measurement uncertainty models in blood establishments' screening immunoassays.

    PubMed

    Pereira, Paulo; Westgard, James O; Encarnação, Pedro; Seghatchian, Jerard; de Sousa, Gracinda

    2015-02-01

    Blood establishments routinely perform screening immunoassays to assess safety of the blood components. As with any other screening test, results have an inherent uncertainty. In blood establishments the major concern is the chance of false negatives, due to its possible impact on patients' health. This article briefly reviews GUM and diagnostic accuracy models for screening immunoassays, recommending a scheme to support the screening laboratories' staffs on the selection of a model considering the intended use of the screening results (i.e., post-transfusion safety). The discussion is grounded on a "risk-based thinking", risk being considered from the blood donor selection to the screening immunoassays. A combination of GUM and diagnostic accuracy models to evaluate measurement uncertainty in blood establishments is recommended. PMID:25620757

  19. [Advances in heavy metal ions immunoassay].

    PubMed

    Liu, Gong-Liang; Wang, Ju-Fang; Li, Zhi-Yong; Liang, Shi-Zhong

    2006-11-01

    Heavy metal leftover on farm and stock products has become a big threat to human. It is necessary to develop some fast and efficient detection methods. Heavy metal immunoassays are new methods for detection of heavy metal ions. Compared to the traditional chemical methods, immunoassays are not only fast, cheap, simple, but also reasonably portable, highly sensitive and selective. It can be used as preliminary screening for rapid determination of heavy metal ions. Except chemical chelators, phytochelatin and metallothionein can also be used for preparing immunogen, both of them can chelate heavy metal ions to carrier protein. There are two prototype assays: polyclonal antibody immunoassay and monoclonal antibody immunoassay. The former includes fluorescence polarization immunoassay; the latter includes indirectly competitive ELISA, one-step competitive immunoassay and KinExA immunoassay. Among these assays, indirectly competitive ELISA which was used for determining heavy metal ions in the early days was easy to be interfered and showed false positive. Fluorescence polarization immunoassay which used polyclonal antibody for determining heavy metal ions was simple and cheap. KinExA instrument could be functioned as an immunosensor for environmental samples. One-step immunoassay which avoided to the addition of second antibody and chromogenic substrate was simple and sensitive. Colloidal gold enhanced immunochromatography assay is a semi-quantitation for determining heavy metal ions. As an adjunctive way for chemical methods, it has the potential application in rapid determination of heavy metal ions. PMID:17168306

  20. IMMUNOASSAYS FOR METAL IONS. (R824029)

    EPA Science Inventory

    Abstract

    Antibodies that recognize chelated forms of metal ions have been used to construct immunoassays for Cd(II), Hg(II), Pb(II), and Ni(II). In this paper, the format of these immunoassays is described and the binding properties of three monoclonal antibodies direc...

  1. Survey of immunoassay techniques for biological analysis

    SciTech Connect

    Burtis, C.A.

    1986-10-01

    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.

  2. Electrokinetic Microstrirring to Enhance Immunoassays

    NASA Astrophysics Data System (ADS)

    Feldman, Hope; Sigurdson, Marin; Meinhart, Carl

    2006-11-01

    Electrokinetic microstirring is used to improve the sensitivity of microfluidic heterogeneous immuno-sensors by enhancing the transport in diffusion-limited reactions. The AC electrokinetic force, Electrothermal Flow, is exploited to create a circular stirring fluid motion, thereby providing more binding opportunities between suspended and wall-immobilized molecules. This process can significantly reduce test times, important for both field-portable biosensors and for lab-based assays. A 2-D numerical simulation model is used to predict the effect of electrothermal flow on a heterogeneous immunoassay resulting from an AC potential applied to two parallel electrodes. The binding is increased by a factor of 7 for an applied voltage of 10 Vrms. The effect was investigated experimentally using a high affinity biotin-streptavidin reaction. Microstirred reaction rates were compared with passive reactions. The measurements show on average an order of magnitude increase in binding between immobilized biotin and fluorescently-labeled streptavidin after 5 minutes. Therefore, this technique shows significant promise for reducing incubation time and enhancing the sensitivity of immunoassays.

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

    NASA Astrophysics Data System (ADS)

    Weigl, Bernhard H.; Hatch, Anson; Kamholz, Andrew E.; Yager, Paul

    2000-03-01

    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.

  4. Finding a Donor

    MedlinePlus

    ... our daughters life A single mother's transplant story Knowledge is power Donor stories Paul, marrow donor, explains donation process Nehal and Rohit donate their baby's cord blood to help others Parents Monique and Michael talk ...

  5. National Marrow Donor Program

    MedlinePlus

    ... our daughters life A single mother's transplant story Knowledge is power Donor stories Paul, marrow donor, explains donation process Nehal and Rohit donate their baby's cord blood to help others Parents Monique and Michael talk ...

  6. Donor cell myeloid sarcoma.

    PubMed

    Walshauser, Mark A; Go, Aileen; Sojitra, Payal; Venkataraman, Girish; Stiff, Patrick

    2014-01-01

    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. PMID:24822132

  7. Donor Cell Myeloid Sarcoma

    PubMed Central

    Walshauser, Mark A.; Sojitra, Payal

    2014-01-01

    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. PMID:24822132

  8. Evaluating Quantum Dot Performance in Homogeneous FRET Immunoassays for Prostate Specific Antigen.

    PubMed

    Bhuckory, Shashi; Lefebvre, Olivier; Qiu, Xue; Wegner, Karl David; Hildebrandt, Niko

    2016-01-01

    The integration of semiconductor quantum dots (QDs) into homogeneous Förster resonance energy transfer (FRET) immunoassay kits for clinical diagnostics can provide significant advantages concerning multiplexing and sensitivity. Here we present a facile and functional QD-antibody conjugation method using three commercially available QDs with different photoluminescence (PL) maxima (605 nm, 655 nm, and 705 nm). The QD-antibody conjugates were successfully applied for FRET immunoassays against prostate specific antigen (PSA) in 50 µL serum samples using Lumi4-Tb (Tb) antibody conjugates as FRET donors and time-gated PL detection on a KRYPTOR clinical plate reader. Förster distance and Tb donor background PL were directly related to the analytical sensitivity for PSA, which resulted in the lowest limits of detection for Tb-QD705 (2 nM), followed by Tb-QD655 (4 nM), and Tb-QD605 (23 nM). Duplexed PSA detection using the Tb-QD655 and Tb-QD705 FRET-pairs demonstrated the multiplexing ability of our immunoassays. Our results show that FRET based on QD acceptors is suitable for multiplexed and sensitive biomarker detection in clinical diagnostics. PMID:26861327

  9. Evaluating Quantum Dot Performance in Homogeneous FRET Immunoassays for Prostate Specific Antigen

    PubMed Central

    Bhuckory, Shashi; Lefebvre, Olivier; Qiu, Xue; Wegner, Karl David; Hildebrandt, Niko

    2016-01-01

    The integration of semiconductor quantum dots (QDs) into homogeneous Förster resonance energy transfer (FRET) immunoassay kits for clinical diagnostics can provide significant advantages concerning multiplexing and sensitivity. Here we present a facile and functional QD-antibody conjugation method using three commercially available QDs with different photoluminescence (PL) maxima (605 nm, 655 nm, and 705 nm). The QD-antibody conjugates were successfully applied for FRET immunoassays against prostate specific antigen (PSA) in 50 µL serum samples using Lumi4-Tb (Tb) antibody conjugates as FRET donors and time-gated PL detection on a KRYPTOR clinical plate reader. Förster distance and Tb donor background PL were directly related to the analytical sensitivity for PSA, which resulted in the lowest limits of detection for Tb-QD705 (2 ng/mL), followed by Tb-QD655 (4 ng/mL), and Tb-QD605 (23 ng/mL). Duplexed PSA detection using the Tb-QD655 and Tb-QD705 FRET-pairs demonstrated the multiplexing ability of our immunoassays. Our results show that FRET based on QD acceptors is suitable for multiplexed and sensitive biomarker detection in clinical diagnostics. PMID:26861327

  10. [FT4 immunoassay interference : A case report].

    PubMed

    Chaabouni, Khansa; Hargafi, Khaoula; Elleuch, Aida; Messedi, Mariem; Turki, Mouna; Lahyani, Amina; Ayedi, Fatma

    2015-04-01

    Measurement of thyrotropin and free thyroxin made using immunoassays are usually needed in clinical endocrinology. Here, we report a case of a patient with type 2 diabetes who presented a weight loss. To eliminate hyperthyroidism, thyroid function tests were performed. Free thyroxin (FT4) was decreased using two automated immunoassays TOSOH AIA 1800 and Roche ELECSYS 2010, with a normal thyrotropin value. Thyroid function tests repeated a month later were normal. The patient's history revealed contact with sheep, which may partly explain the interference. Investigations into the patient's serum were carried out using both the PEG test and dilution test. Interference factors were probably antibodies. Despite progress in immunoassays, we should be aware of interference occurrence since it can lead to false results, unnecessary investigations and incorrect treatment. Thus, simple tests must be carried out as if interference in immunoassays were suspected. Dilutions and PEG tests are generally performed as first line investigations. PMID:26375746

  11. Automated immunoassays for 25-hydroxyvitamin D (25-OHD): do plasticisers interfere?

    PubMed

    Carter, G D; Jones, J; Ketheeswaran, M; Shannon, J; Singh, B; Kearney, E; Berry, J L

    2015-04-01

    The international quality assessment scheme for vitamin D metabolites (DEQAS) was established in 1989. The scheme involves the quarterly distribution of 5 serum samples prepared from blood collected in plain plastic bags. Following transfer of the donors to a clinic using different bags, sera were found to contain a contaminant that interfered in both the local LC-MS/MS assay and the NIST reference measurement procedure for 25-OHD. It seemed likely that the contaminant was a substance, possibly a plasticiser, leached from the plastic bag. It was subsequently suggested that the unidentified contaminant might also cause interference in certain automated non-extraction assays for 25-OHD. This was investigated in 3 automated immunoassays by comparing serum 25-OHD results from blood collected simultaneously into plain glass tubes and plastic bags. There was no significant difference in results, indicating that the leached substance had no effect on any of the 3 immunoassays examined. PMID:25448742

  12. Living Related Kidney Donors

    PubMed Central

    Lazarovits, Andrew I.

    1992-01-01

    A kidney transplant is the treatment of choice for suitable patients with end-stage renal disease. The living related kidney donor represents an important source of kidneys because graft survival is much better and there is a critical shortage of organ donors. This article reviews the risks to the donor and the means by which these individuals are assessed in order to minimize the risk. PMID:21221370

  13. O-Glycosyl Donors

    NASA Astrophysics Data System (ADS)

    Lpez, J. Cristbal

    O-Glycosyl donors, despite being one of the last successful donors to appear, have developed themselves into a burgeoning class of glycosyl donors. They can be classified in two main types: O-alkyl and O-aryl (or hetaryl) glycosyl donors. They share, however, many characteristics, they can be (1) synthesized from aldoses, either by modified Fisher glycosidation (O-alkyl) or by nucleophilic aromatic substitution (O-aryl or O-hetaryl), (2) stable to diverse chemical manipulations, (3) directly used for saccharide coupling, and (4) chemoselectively activated. Among these, n-pentenyl glycosides stand apart. They were the first O-alkyl glycosyl donors to be described and have paved the way to many conceptual developments in oligosaccharide synthesis. The development of the chemoselectivity-based "armed-disarmed" approach for saccharide coupling, including its stereoelectronic or torsional variants, now extended to other kinds of glycosyl donors, was first recognized in n-pentenyl glycosides. The chemical manipulation of the anomeric substituent in the glycosyl donor to induce reactivity differences between related species (sidetracking) was also introduced in n-pentenyl glycosides. An evolution of this concept, the "latent-active" strategy for glycosyl couplings, first described in thioglycosyl donors (vide infra), has been elegantly applied to O-glycosyl donors. Thus, allyl and vinyl glycosides, 2-(benzyloxycarbonyl)benzyl (BCB) glycosides and 2'-carboxybenzyl (CB) glycosides are useful "latent-active" glycosyl pairs. Finally, unprotected 3-methoxy-2-pyridyl (MOP) glycosides have been used in glycosylation processes with moderate success.

  14. Donor Tag Game

    MedlinePlus

    ... Donation Student Donors Donation Process Eligibility Blood FAQs Blood Donor Community Learn About Blood Blood Facts and Statistics Blood Types Blood Components What Happens to Donated Blood Blood and Diversity History of Blood Transfusion Hosting a Blood Drive What to Expect Hosting ...

  15. Rich Donors, Poor Countries

    ERIC Educational Resources Information Center

    Thomas, M. A.

    2012-01-01

    The shifting ideological winds of foreign aid donors have driven their policy towards governments in poor countries. Donors supported state-led development policies in poor countries from the 1940s to the 1970s; market and private-sector driven reforms during the 1980s and 1990s; and returned their attention to the state with an emphasis on…

  16. Donor Telomere Length SAA

    Cancer.gov

    A new NCI study has found that, among patients with severe aplastic anemia who received a hematopoietic cell transplant from an unrelated donor, those whose donor white blood cells had longer telomeres had higher survival rates five-years after transplant

  17. Highly Sensitive Homogeneous Immunoassays Based on Construction of Silver Triangular Nanoplates-Quantum Dots FRET System.

    PubMed

    Zeng, Qinghui; Li, Qin; Ji, Wenyu; Bin, Xue; Song, Jie

    2016-01-01

    With growing concerns about health issues worldwide, elegant sensors with high sensitivity and specificity for virus/antigens (Ag) detection are urgent to be developed. Homogeneous immunoassays (HIA) are an important technique with the advantages of small sample volumes requirement and pretreatment-free process. HIA are becoming more favorable for the medical diagnosis and disease surveillance than heterogeneous immunoassays. An important subset of HIA relies on the effect of fluorescence resonance energy transfer (FRET) via a donor-acceptor (D-A) platform, e.g., quantum dots (QDs) donor based FRET system. Being an excellent plasmonic material, silver triangular nanoplates (STNPs) have unique advantages in displaying surface plasmon resonance in the visible to near infrared spectral region, which make them a better acceptor for pairing with QDs in a FRET-based sensing system. However, the reported STNPs generally exhibited broad size distributions, which would greatly restrict their application as HIA acceptor for high detection sensitivity and specificity purpose. In this work, uniform STNPs and red-emitting QDs are firstly applied to construct FRET nanoplatform in the advanced HIA and further be exploited for analyzing virus Ag. The uniform STNPs/QDs nanoplatform based medical sensor provides a straightforward and highly sensitive method for Ag analysis in homogeneous form. PMID:27198713

  18. FRET-based homogeneous immunoassay on a nanoparticle-based photonic crystal.

    PubMed

    Han, Jin-Hee; Sudheendra, Lakshmana; Kennedy, Ian M

    2015-07-01

    The potential of fluorescence resonance energy transfer (FRET) in a photonic crystal (PC) nanostructured array to enhance the speed and sensitivity of a protein-based immunoassay was tested. Forty-nanometer carboxylated particles conjugated with donor-labeled capture antibodies were trapped by electrophoresis and used as a FRET energy donor. The PC array was able to enhance fluorescent excitation and emission by phase matching. To provide a proof of concept for this FRET-based homogeneous assay on a PC chip, an immunoassay was tested with a simple immunoglobulin G (IgG)-based reaction. A standard curve was generated by testing two different antibody reaction times: 20 min. and 1 min. The results were compared directly to those obtained from a FRET assay that used a modern, high-sensitivity plate reader with a 96-well plate and a reaction time of 1 h. The rabbit-IgG detection limits of the FRET-based homogeneous assay on the PC were 0.001 and 0.1 μg/mL for incubation times of 20 and 1 min, respectively; the sensitivities were 10(3) and 10 times better than the 96-well plate reader, respectively. Thus, FRET on a PC immunoplatform was shown to be a facile, effective, rapid, and sensitive detection technology. PMID:25956600

  19. Homogeneous model immunoassay of thyroxine by phase-modulation fluorescense spectroscopy

    NASA Astrophysics Data System (ADS)

    Ozinskas, Alvydas J.; Malak, Henryk M.; Britz, Judy; Thompson, Richard B.; Koen, Peter A.; Lakowicz, Joseph R.

    1993-05-01

    We describe a homogeneous competitive model immunoassay for determination of thyroxine by multi-frequency phase-modulation fluorescence. Using a non-radiative energy transfer transduction mechanism, B-phycoerythrin conjugated to thyroxine is the energy donor and a carboxymethylindocyanine dye conjugated to anti-thyroxine antibody is the energy acceptor. Energy transfer from B-phycoerythrin to the acceptor results in a decreased lifetime and/or phase angle. The fluorescence lifetime change reflects the extent of energy transfer. In the competitive immunoassay format, the donor-thyroxine conjugate and an analytical sample of thyroxine compete for acceptor-antibody binding sites, resulting in a phase angle change which is dependent on the amount of thyroxine in the sample. Dose response curves of phase angle versus thyroxine concentration demonstrate a broader dynamic range than comparable steady state intensity curves. Since phase-modulation lifetime measurements are largely independent of total signal intensity, sources of optical interference are minimized. The potential for whole blood measurements exists since the energy transfer lifetime method can be extended to longer wavelengths.

  20. Rational design of a low-affinity peptide for the detection of cystatin C in a fast homogeneous immunoassay.

    PubMed

    Dobslaff, Kristin; Zscharnack, Kristin; Kreisig, Thomas; Zuchner, Thole

    2016-02-01

    Immunoassays play an essential role in current research and diagnostics resulting in a variety of detection principles. Thereby, homogeneous assays are often used for a fast signal response as demanded for example in point-of-care diagnostics. These systems often rely on a competitive assay design where the sample analyte and the corresponding dye-labeled substance are competing for binding sites on an antibody present in limited amounts. Due to the similar affinities of the antibody towards the sample analyte and the competitor, both sensitivity and assay time are limited. As a consequence, a competitor with a slightly reduced affinity towards the antibody can potentially overcome these drawbacks. Here, we present the rational design of a low-affinity peptide (donor peptide) as a specific analyte competitor for a FRET-based homogeneous immunoassay for the analysis of the protein cystatin C. Thereby, the strategy of peptide-induced antibody generation was combined with the selective variation of the immunization sequence in order to achieve a lower affinity towards the antibody. We could show that shortened donor peptides improved the resulting quenching efficiency in the immunoassay. In addition, the substitution of small hydrophobic amino acids by those with a higher steric demand appeared to be the most promising strategy providing a fast assay response for cystatin C of only 90 s. PMID:26403846

  1. Theoretical limitations of quantification for noncompetitive sandwich immunoassays.

    PubMed

    Woolley, Christine F; Hayes, Mark A; Mahanti, Prasun; Douglass Gilman, S; Taylor, Tom

    2015-11-01

    Immunoassays exploit the highly selective interaction between antibodies and antigens to provide a vital method for biomolecule detection at low concentrations. Developers and practitioners of immunoassays have long known that non-specific binding often restricts immunoassay limits of quantification (LOQs). Aside from non-specific binding, most efforts by analytical chemists to reduce the LOQ for these techniques have focused on improving the signal amplification methods and minimizing the limitations of the detection system. However, with detection technology now capable of sensing single-fluorescence molecules, this approach is unlikely to lead to dramatic improvements in the future. Here, fundamental interactions based on the law of mass action are analytically connected to signal generation, replacing the four- and five-parameter fittings commercially used to approximate sigmoidal immunoassay curves and allowing quantitative consideration of non-specific binding and statistical limitations in order to understand the ultimate detection capabilities of immunoassays. The restrictions imposed on limits of quantification by instrumental noise, non-specific binding, and counting statistics are discussed based on equilibrium relations for a sandwich immunoassay. Understanding the maximal capabilities of immunoassays for each of these regimes can greatly assist in the development and evaluation of immunoassay platforms. While many studies suggest that single molecule detection is possible through immunoassay techniques, here, it is demonstrated that the fundamental limit of quantification (precision of 10 % or better) for an immunoassay is approximately 131 molecules and this limit is based on fundamental and unavoidable statistical limitations. PMID:26342315

  2. Managing finances of shipping living donor kidneys for donor exchanges.

    PubMed

    Mast, D A; Vaughan, W; Busque, S; Veale, J L; Roberts, J P; Straube, B M; Flores, N; Canari, C; Levy, E; Tietjen, A; Hil, G; Melcher, M L

    2011-09-01

    Kidney donor exchanges enable recipients with immunologically incompatible donors to receive compatible living donor grafts; however, the financial management of these exchanges, especially when an organ is shipped, is complex and thus has the potential to impede the broader implementation of donor exchange programs. Representatives from transplant centers that utilize the National Kidney Registry database to facilitate donor exchange transplants developed a financial model applicable to paired donor exchanges and donor chain transplants. The first tenet of the model is to eliminate financial liability to the donor. Thereafter, it accounts for the donor evaluation, donor nephrectomy hospital costs, donor nephrectomy physician fees, organ transport, donor complications and recipient inpatient services. Billing between hospitals is based on Medicare cost report defined costs rather than charges. We believe that this model complies with current federal regulations and effectively captures costs of the donor and recipient services. It could be considered as a financial paradigm for the United Network for Organ Sharing managed donor exchange program. PMID:21831153

  3. Multiplexed Microsphere Suspension Array-Based Immunoassays.

    PubMed

    Lin, Andrew; Salvador, Alexandra; Carter, J Mark

    2015-01-01

    ELISA is an extremely powerful tool to detect analytes because of its sensitivity, selectivity, reproducibility and ease of use. Here we describe sandwich immunoassays performed in suspension on spectrally unique microspheres developed by Luminex. Luminex assays offer the benefit of multiplex analysis of large numbers of analytes in a single reaction. Because the microspheres are spectrally unique, many microspheres, each attached to various antibodies, can be added to a single sample. Luminex instruments can distinguish each microsphere and detect the intensity of a reporter signal for each microsphere. Results are reported in Median Fluorescent Intensities for each analyte. Luminex assays can be used to detect up to 500 analytes in a high-throughput format. Luminex refers to this technology as xMAP(®). Here we describe a routine protocol for a Luminex immunoassay. Other Luminex assays would have to be optimized for specific conditions according to their use. PMID:26160569

  4. Sequential injection immunoassay for environmental measurements.

    PubMed

    Soh, Nobuaki; Tanaka, Mayumi; Hirakawa, Koji; Zhang, RuiQi; Nakajima, Hizuru; Nakano, Koji; Imato, Toshihiko

    2011-01-01

    Sequential injection immunoassay systems for environmental measurements based on the selective immunoreaction between antigen and antibody were described. A sequential injection analysis (SIA) technique is suitable to be applied for the procedure of enzyme-linked immunosorbent assay (ELISA), because the washing and the addition of reagent solutions can be automated by using a computer-controlled syringe pump and switching valve. We selected vitellogenin (Vg), which is a biomarker for evaluating environmental risk caused by endocrine-disrupting chemicals in the hydrosphere, and linear alkylbenzene sulfonates (LAS) and alkylphenol polyethoxylates (APEO), which are versatile surfactants, as target analytes in the flow immunoassay systems. For Vg monitoring, SIA systems based on spectrophotometric, chemiluminescence, and electrochemical determinations were constructed. On the other hand, chemiluminescence determination was applied to the detection of LAS and APEO. For APEO, an SIA system combined with surface plasmon resonance (SPR) sensor was also developed. These new sequential injection immunoassay systems are expected to be useful systems for environmental analysis. PMID:22076332

  5. Homogeneous Immunoassays: Historical Perspective and Future Promise

    NASA Astrophysics Data System (ADS)

    Ullman, Edwin F.

    1999-06-01

    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.

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

    PubMed

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

    2012-12-01

    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

  7. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays

    PubMed Central

    Chen, Hui; Hagström, Anna E. V.; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C.; Atmar, Robert L.; Willson, Richard C.

    2016-01-01

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 106 virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings. PMID:27075635

  8. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays.

    PubMed

    Chen, Hui; Hagström, Anna E V; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C; Atmar, Robert L; Willson, Richard C

    2016-01-01

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 10(6) virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings. PMID:27075635

  9. Dialing for Donors

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2012-01-01

    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

  10. Becoming a Donor

    MedlinePlus

    ... because of the shortage of donated organs. For characteristics about waitlisted patients, such as gender, age, or organs needed, go to the U.S. Waiting List Candidates by Organ and Gender. > U.S. Waiting List Candidate Data HOW TO BECOME A DONOR The most important thing to do is to sign up as an ...

  11. Dialing for Donors

    ERIC Educational Resources Information Center

    Schaffhauser, Dian

    2012-01-01

    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…

  12. [Living donor liver transplantation].

    PubMed

    Tanaka, K; Kaihara, S

    2003-10-01

    Liver transplantation has evolved into the standard treatment for numerous endstage liver diseases. The increase of organ shortages led to living organ donation. In 1988 living donor liver transplantation (LDLT) was performed for the first time. Since then multiple difficulties associated with LDLT have been solved. In Kyoto we can look back on more than 900 transplantations since the initiation of our LDLT program in 1990, which is the oldest in Japan and the largest in the world. In the following we review our extensive experience with special focus on issues such as donor safety, results after LDLT, and potential complications in the recipient. Further, graft size mismatching, venous drainage from anterior segment of the right lobe graft, LDLT for hepatocellular carcinoma, AB0-incompatible transplantation, and recurrence of hepatitis C infection, which are still unsolved problems in LDLT, are described and future directions are indicated. PMID:14605737

  13. Enzyme immunoassays with special reference to ELISA techniques.

    PubMed Central

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

    1978-01-01

    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. PMID:78929

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

    SciTech Connect

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

    1986-07-18

    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.

  15. Nanomaterial Labels in Electrochemical Immunosensors and Immunoassays

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2007-12-15

    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.

  16. Fluorescent immunoassay visualization of sorbed pollutants

    SciTech Connect

    Moore, W.K.; Mossman, D.J.; Schwab, A.P.; Feldbush, T.L.

    1994-12-31

    Current methods of detecting sorbed soil pollutants require that the contaminant be extracted from the soil. In an effort to make detection simpler and safer, standard fluorescent immunoassay techniques are being modified to allow fluorescent tags on the pollutant to be viewed and photographed with epifluorescent microscopy. Initial research focuses on detecting chlorinated benzenes on various soil types and developing a technique for tagging these pollutants with appropriate antibodies. This should lead to detection in actual soil cores and a better understanding of how contaminants progress through different soils.

  17. Gliadin Detection in Food by Immunoassay

    NASA Astrophysics Data System (ADS)

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

    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.

  18. Nanomaterial Labels in Electrochemical Immunosensors and Immunoassays

    PubMed Central

    Liu, Guodong; Lin, Yuehe

    2009-01-01

    This article reviews recent advances in nanomaterial labels in electrochemical immunosensors and immunoassays. Various nanomaterial labels are discussed, including colloidal gold/silver, semiconductor nanoparticles, and markers loaded nanocarriers (carbon nanotubes, apoferritin, silica nanoparticles, and liposome beads). The enormous signal enhancement associated with the use of nanomaterial labels and with the formation of nanomaterialantibody-antigen assemblies provides the basis for ultrasensitive electrochemical detection of disease-related protein biomarkers, biothreat agents, or infectious agents. In general, all endeavors cited here are geared to achieve one or more of the following goals: signal amplification by several orders of magnitude, lower detection limits, and detecting multiple targets. PMID:18371644

  19. Donor heart preservation survey.

    PubMed

    Wheeldon, D; Sharples, L; Wallwork, J; English, T

    1992-01-01

    A questionnaire requesting information on donor heart preservation technique and outcomes during the first 6 months of 1990 was circulated to heart transplantation centers worldwide. Seventy-nine usable replies representing 1371 clinical transplant operations were received. Twenty-seven percent of the respondents reported using some form of donor pretreatment. Most (90%) used single flush cardioplegic induction with the use of eight different types of cardioplegic solutions, only 5% of which were oxygenated. Six different types of storage media were used, and the coolant was melting ice in 66% of the centers. Storage temperatures between 0 degrees C and 7 degrees C were reported, with 78% of the respondents using 4 degrees C storage. Fifty-five percent of the centers used some form of reperfusion modification. No statistically significant associations were noted between outcome and technique, apart from the use of storage medium in which the use of cardioplegic solution conferred a 2.5 times increase in deaths compared with cold saline. The results of this questionnaire provide evidence for the diversity of techniques currently used for donor heart preservation, reflecting the lack of any one optimal method. PMID:1420249

  20. Magnetic bead-sensing-platform-based chemiluminescence resonance energy transfer and its immunoassay application.

    PubMed

    Qin, Guoxin; Zhao, Shulin; Huang, Yong; Jiang, Jing; Ye, Fanggui

    2012-03-20

    A competitive immunoassay based on chemiluminescence resonance energy transfer (CRET) on the magnetic beads (MBs) is developed for the detection of human immunoglobulin G (IgG). In this protocol, carboxyl-modified MBs were conjugated with horseradish peroxidase (HRP)-labeled goat antihuman IgG (HRP-anti-IgG) and incubated with a limited amount of fluorescein isothiocyanate (FITC)-labeled human IgG to immobilize the antibody-antigen immune complex on the surface of the MBs, which was further incubated with the target analyte (human IgG) for competitive immunoreaction and separated magnetically to remove the supernatant. The chemiluminescence (CL) buffer (containing luminol and H(2)O(2)) was then added, and the CRET from donor luminol to acceptor FITC in the immunocomplex on the surface of MBs occured immediately. The present protocol was evaluated for the competitive immunoassay of human IgG, and a linear relationship between CL intensity ratio (R = I(425)/I(525)) and human IgG concentration in the range of 0.2-4.0 nM was obtained with a correlation coefficient of 0.9965. The regression equation was expressed as R = 1.9871C + 2.4616, and a detection limit of 2.9 × 10(-11) M was obtained. The present method was successfully applied for the detection of IgG in human serum. The results indicate that the present protocol is quite promising for the application of CRET in immunoassays. It could also be developed for detection of other antigen-antibody immune complexes by using the corresponding antigens and respective antibodies. PMID:22339489

  1. Blood donor management in china.

    PubMed

    Shi, Ling; Wang, Jingxing; Liu, Zhong; Stevens, Lori; Sadler, Andrew; Ness, Paul; Shan, Hua

    2014-07-01

    Despite a steady increase in total blood collections and voluntary non-remunerated blood donors, China continues to have many challenges with its blood donation system. The country's donation rate remains low at 9%o, with over 60% of donors being first-time donors. Generally there is a lack of adequate public awareness about blood donation. The conservative donor selection criteria, the relatively long donation interval, and the small donation volume have further limited blood supply. To ensure a sufficient and safe blood supply that meets the increasing clinical need for blood products, there is an urgent need to strengthen the country's blood donor management. This comprehensive effort should include educating and motivating more individuals especially from the rural areas to be involved in blood donation, developing rational and evidence-based selection criteria for donor eligibility, designing a donor follow-up mechanism to encourage more future donations, assessing the current donor testing strategy, improving donor service and care, building regional and national shared donor deferral database, and enhancing the transparency of the blood donation system to gain more trust from the general public. The purpose of the review is to provide an overview of the key process of and challenges with the blood donor management system in China. PMID:25254023

  2. Blood Donor Management in China

    PubMed Central

    Shi, Ling; Wang, Jingxing; Liu, Zhong; Stevens, Lori; Sadler, Andrew; Ness, Paul; Shan, Hua

    2014-01-01

    Summary Despite a steady increase in total blood collections and voluntary non-remunerated blood donors, China continues to have many challenges with its blood donation system. The country's donation rate remains low at 9%o, with over 60% of donors being first-time donors. Generally there is a lack of adequate public awareness about blood donation. The conservative donor selection criteria, the relatively long donation interval, and the small donation volume have further limited blood supply. To ensure a sufficient and safe blood supply that meets the increasing clinical need for blood products, there is an urgent need to strengthen the country's blood donor management. This comprehensive effort should include educating and motivating more individuals especially from the rural areas to be involved in blood donation, developing rational and evidence-based selection criteria for donor eligibility, designing a donor follow-up mechanism to encourage more future donations, assessing the current donor testing strategy, improving donor service and care, building regional and national shared donor deferral database, and enhancing the transparency of the blood donation system to gain more trust from the general public. The purpose of the review is to provide an overview of the key process of and challenges with the blood donor management system in China. PMID:25254023

  3. Fluorimetric Immunoassay for Multianalysis of Aflatoxins

    PubMed Central

    2013-01-01

    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 μL. 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

  4. Competitive enzyme immunoassay for bovine growth hormone.

    PubMed

    Roh, S G; Matsunaga, N; Miyamoto, A; Hidaka, S; Hidari, H

    1997-02-01

    We developed an enzyme immunoassay (EIA) for bovine GH (bGH) which is based on indirect competitive immunoassay in culture medium from a bovine pituitary cell culture. 40 microliters cell culture samples (or bGH standard) and bGH antibody (rabbit anti-bGH) were added to the 96 well microplate coated with secondary antibody (Goat anti-rabbit IgG), and incubated for 24 h at 37 degrees C. Biotin-label bGH was added and incubated further for 24 h at 37 degrees C, and biotinylated bGH was linked with streptoavidin-peroxidase. Substrates for peroxidase were added to the plate and incubated for 1 h at 4 degrees C. The enzyme reaction was stopped with 4N H2SO4, and the absorbency at 450 nm was measured with an ELISA Reader. The coefficients of intra-assay and inter-assay variations were 4.13 approximately 7.59% and 3.71 approximately 8.27%, respectively. The regression equation and correlation coefficients with the radioimmunoassay (RIA) were y(RIA) = 1.9986 x (EIA) - 1.3921 and 0.9701 (n = 27), respectively. Collectively, the present assay provides a reliable alternative to RIA and offers the major advantage of eliminating radioactive reagents and counting equipment. PMID:9152634

  5. Quantum-dot-basedFrster resonance energy transfer immunoassay for sensitive clinical diagnostics of low-volume serum samples.

    PubMed

    Wegner, K David; Jin, Zongwen; Lindn, Stina; Jennings, Travis L; Hildebrandt, Niko

    2013-08-27

    A myriad of quantum dot (QD) biosensor examples have emerged from the literature over the past decade, but despite their photophysical advantages, QDs have yet to find acceptance as standard fluorescent reagents in clinical diagnostics. Lack of reproducible, stable, and robust immunoassays using easily prepared QD-antibody conjugates has historically plagued this field, preventing researchers from advancing the deeper issues concerning assay sensitivity and clinically relevant detection limits on low-volume serum samples. Here we demonstrate a ratiometric multiplexable FRET immunoassay using Tb donors and QD acceptors, which overcomes all the aforementioned limitations toward application in clinical diagnostics. We demonstrate the determination of prostate specific antigen (PSA) in 50 ?L serum samples with subnanomolar (1.6 ng/mL) detection limits using time-gated detection and two different QD colors. This concentration is well below the clinical cutoff value of PSA, which demonstrates the possibility of direct integration into real-life in vitro diagnostics. The application of IgG, F(ab')2, and F(ab) antibodies makes our homogeneous immunoassay highly flexible and ready-to-use for the sensitive and specific homogeneous detection of many different biomarkers. PMID:23909574

  6. The role of uncertainty regarding the results of screening immunoassays in blood establishments.

    PubMed

    Pereira, Paulo; Westgard, James O; Encarnação, Pedro; Seghatchian, Jerard; de Sousa, Gracinda

    2015-04-01

    The risk of uncertain results in infectious agents' tests is recognized in blood establishments, being particularly evident during the blood donor selection. The current risk-based approaches require risk assessment and "risk-based thinking". Accordingly, the blood establishment should consider the effect of uncertainty in all the technical decisions taken in a screening laboratory. Since the post-transfusion safety is one of the blood establishments' goals, the risk of post-transfusion infection should be evaluated and actions taken to decrease the chance of blood donations validation use false negative results. This article reviews and discusses the sources of uncertainty of infectious agents' reported results in blood establishments. It describes a set of sources of uncertainty that should be considered in screening immunoassay's decisions. The infectious agents' uncertainty concern is critical for reporting reliable results. PMID:25754470

  7. Amphetamine Positive Urine Toxicology Screen Secondary to Atomoxetine

    PubMed Central

    Fenderson, Joshua L.; Stratton, Amy N.; Domingo, Jennifer S.; Matthews, Gerald O.; Tan, Christopher D.

    2013-01-01

    The aim of this paper is to report the first case of atomoxetine leading to false-positive urine drug screen. An otherwise healthy 27-year-old female with a history of attention deficit hyperactivity disorder (ADHD) treated with atomoxetine had an acute onset tonic-clonic seizure. On arrival to the hospital, a urine toxicological drug screen with immunochemical cloned enzyme donor immunoassay (CEDIA) was performed. Results were positive for amphetamines; however, the presence of these substances could not be confirmed with urine gas chromatography-mass spectrometry (GC-MS). She denied any illicit drug use, herbal medications, or supplements, and her other prescription medications have not been previously known to cause a false-positive result for amphetamines. While stimulant treatments for ADHD could certainly result in a positive result on urine screen for amphetamines, there have been no reports of false-positive results for amphetamines secondary to patients using atomoxetine. We implicate atomoxetine, and/or its metabolites, as a compound or compounds which may interfere with urine drug immunoassays leading to false-positive results for amphetamines CEDIA assays. PMID:23424703

  8. Outcomes of living donor liver transplantation using elderly donors

    PubMed Central

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

    2014-01-01

    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. PMID:24783177

  9. Comparison of immunoassay screening tests and LC-MS-MS for urine detection of benzodiazepines and their metabolites: results of a national proficiency test.

    PubMed

    Bertol, Elisabetta; Vaiano, Fabio; Borsotti, Maurizio; Quercioli, Massimo; Mari, Francesco

    2013-01-01

    For most diverse purposes, different immunoassay (IA) screening methods are usually used to detect benzodiazepines and their metabolites in urine. In this study, we compared the main IAs used in forensic toxicology (Cloned Enzyme Donor Immunoassay, CEDIA®; Enzyme-Multiplied Immunoassay Technique, EMIT®; Fluorescent Polarization ImmunoAssay, FPIA®; Kinetic Interaction of Microparticles in Solution, KIMS® and Immunochromatographic Techniques, IMC) with liquid chromatography-tandem mass spectrometry (LC-MS-MS). Twelve urine specimens were analyzed by 178 laboratories in Italy that participated in a National Proficiency Test, providing both qualitative and semi-quantitative results. Each IA was evaluated by the parameters: true positive, true negative, false positive (FP), false negative (FN), sensitivity (SENS), specificity (SPEC), positive predictive value, negative predictive value (NPV) and accuracy. SPEC was affected by a high FP rate for all IAs. The lowest SENS and NPV were provided by FPIA due to a high number of FN cases. Comparing IA semi-quantitative data with LC-MS-MS results, an overestimation of benzodiazepine amount is noted. This paper draws attention to the problem of the careless use of IA tests for forensic purposes as they may provide FP and/or FN results that can lead to errors of great severity. PMID:23943436

  10. Environmental Immunoassays: Alternative Techniques for Soil and Water Analysis

    USGS Publications Warehouse

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

    1996-01-01

    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.

  11. Neutralization enzyme immunoassay for influenza virus.

    PubMed Central

    Benne, C A; Harmsen, M; De Jong, J C; Kraaijeveld, C A

    1994-01-01

    A neutralization enzyme immunoassay (N-EIA) was developed for the detection of antibody titer rises in sera of patients infected with influenza A (H3N2) virus. In this N-EIA, a selected strain of influenza A (H3N2) virus was added to monolayers of LLC-MK2 cells in microtiter plates. After 24 h, the replicated virus could be demonstrated with a virus-specific enzyme-labeled monoclonal antibody. Preincubation of the influenza virus with convalescent-phase sera of patients infected with influenza A (H3N2) virus resulted 1 day later in decreased absorbance values that could be used for calculation of neutralization titers. From use of paired serum samples from 10 patients with a history of flu-like symptoms, the results obtained with N-EIA correlated well (r = 0.83) with those of the standard hemagglutination inhibition test. PMID:8027355

  12. Nanoparticles for Enhanced Sensitivity in Electrochemical Immunoassays

    SciTech Connect

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

    2008-10-12

    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.

  13. [Detection of food additives by enzyme immunoassay].

    PubMed

    Yoshida, A; Takagaki, Y

    1995-09-01

    The analysis of synthesized food additives is generally performed by chromatography or spectrophotometry. However, the analytical procedures for natural food additives have been little reported so far because they are difficult to analyse chemically. We have attempted to apply enzyme immunoassay (EIA) to the analysis of natural food additives. Hen egg white lysozyme, as a food preservative, was determined by the competitive EIA, using mouse anti-HEL ascites. Carminic acid (CA), which is the main component of cochineal color, was determined by the competitive EIA, using monoclonal anti-CA antibody. Phycocyanin, which is the main component of spirulina color, was determined by the avidin-biotin sandwich EIA, using double monoclonal anti-phycocyanin antibodies. PMID:7474399

  14. Immunoassay procedures for fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Ligler, Frances S.

    1988-04-01

    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.

  15. Flow immunoassay using solid-phase entrapment.

    PubMed

    Locascio-Brown, L; Martynova, L; Christensen, R G; Horvai, G

    1996-05-01

    A flow injection immunoassay was performed using a column packed with reversed-phase sorbents to effect separation of the immunoreacted species by entrapping free analyte and allowing antibody-conjugated analyte to pass unretained. Fluorescein-labeled analyte was measured in a competitive assay for the anticonvulsant drug phenytoin. The simplicity of the assay was the greatest advantage of the technique, which allowed for measurement of phenytoin in a 2-min assay time. The reliable detection limit for the assay was 5 nmol L(-)(1) of phenytoin in serum. The columns were regenerated with periodic injections of ethanol solutions to remove the entrapped analyte and prepare the column for subsequent analyses. PMID:21619134

  16. 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...

  17. Donor cell leukemia.

    PubMed

    Ruiz-Arguelles, Alejandro

    2012-04-01

    Minimal residual disease refers to the tumour cells that are still present in a given patient after completion of a therapeutic scheme. The demonstration and quantification of residual neoplastic cells has a crucial impact in clinical decision making, for it might prompt continuation of treatment, while the absence of such cells might serve as evidence to withdraw therapy. Therefore, both sensitivity and specificity of the methods used to unravel residual neoplastic cells must be highly reliable and robust. Flow cytometry has been widely used for this purpose, and its clinical performance depends mainly on the criteria of interpretation, rather than in the technique by itself; molecular biology techniques have proved to be highly sensitive and specific but unfortunately they cannot be used in all patients or in all types of leukemia. Finally, the development of donor cell leukemia in transplanted patients, might mimic residual disease and add more confusion to an already controversial issue. These topics are discussed in this paper. PMID:22507784

  18. Detection of narcotics with an immunoassay film badge

    SciTech Connect

    Lukens, H.R.

    1993-12-31

    Efficient personnel performance, a major requirement for a safe nuclear industry, is jeopardized where personnel use narcotics. However, detection of narcotics at nuclear plants is a challenge. The unique specificity and sensitivity of an immunoassay has been implemented in the form of a small, dry immunoassay film badge (IFB) for the detection of vapors emitted by narcotics. The device is suitable as an area monitor, and its characteristics are suitable for use as a breath monitor for the detection of drug use.

  19. Clinical Applications of Capillary Electrophoresis-Based Immunoassays

    PubMed Central

    Moser, Annette C.; Willicott, Corey W.; Hage, David S.

    2014-01-01

    Immunoassays have long been an important set of tools in clinical laboratories for the detection, diagnosis and treatment of disease. Over the last two decades there has been growing interest in utilizing capillary electrophoresis (CE) as a means for conducting immunoassays with clinical samples. The resulting method is known as a CE immunoassay. This approach makes use of the selective and strong binding of antibodies for their targets, as is employed in a traditional immunoassay, and combines this with the speed, efficiency, and small sample requirements of CE. This review discusses the variety of ways in which CE immunoassays have been employed with clinical samples. An overview of the formats and detection modes that have been employed in these applications is first presented. A more detailed discussion is then given on the type of clinical targets and samples that have been measured or studied by using CE immunoassays. Particular attention is given to the use of this method in the fields of endocrinology, pharmaceutical measurements, protein and peptide analysis, immunology, infectious disease detection, and oncology. Representative applications in each of these areas are described, with these examples involving work with both traditional and microanalytical CE systems. PMID:24132682

  20. Donor Preferences and Charitable Giving

    ERIC Educational Resources Information Center

    Williams, Stephanie Roderick

    2007-01-01

    This study aimed to learn more of the differences that may exist between the two most powerful groups of donors today, baby boomers (40-58 years old) and mature donors (59 and older), in an effort to help organizations improve fundraising efforts. Questions about the importance of organizational efficiency, program outcomes, and the desire for…

  1. Marrow transplantation from unrelated donors.

    PubMed

    Sierra, J; Anasetti, C

    1995-11-01

    The use of an HLA-compatible unrelated donor is an option for patients who require an allogeneic transplant but lack a family member match. Grafts from unrelated volunteer donors have provided long-term disease-free survival for a variable proportion of patients, depending on degree of HLA matching with the donor, patient's disease, disease stage, and age. The number of volunteers in marrow donor registries worldwide has increased to more than 2.5 million. The number of unrelated donor transplants facilitated by the US National Marrow Donor Program alone will exceed 900 this year. Progress in HLA-typing technology results in a more precise definition of donor and recipient matching and new assays have been developed with initial success to measure alloreactive T-cell precursors for selection of donors with less antihost reactivity. Prevention and treatment of graft failure, graft-versus-host disease, opportunistic infections, and Epstein-Barr virus-associated lymphoproliferative disease remain a challenge. PMID:9372034

  2. Management of Young Blood Donors

    PubMed Central

    Newman, Bruce H.

    2014-01-01

    Summary The emphasis on high-school blood drives and acceptance of 16-year-old blood donors led to more research on physiologic and psychological ways to decrease vasovagal reaction rates in young blood donors and to increase donor retention. Research on how to accomplish this has been advantageous for the blood collection industry and blood donors. This review discussed the current situation and what can be done psychologically, physiologically, and via process improvements to decrease vasovagal reaction rates and increase donor retention. The donation process can be significantly improved. Future interventions may include more dietary salt, a shorter muscle tension program to make it more feasible, recommendations for post-donation muscle tension / squatting / laying down for lightheadedness, more donor education by the staff at the collection site, more staff attention to donors with fear or higher risk for a vasovagal reaction (e.g. estimated blood volume near 3.5 l, first-time donor), and a more focused donation process to ensure a pleasant and safer procedure. PMID:25254024

  3. 21 CFR 630.6 - Donor notification.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... attempts to notify any donor, including an autologous donor, who has been deferred based on the results of... reasonable attempts to notify the donor. (d) Autologous donors. (1) You also must provide the following information to the referring physician of an autologous donor who is deferred based on the results of...

  4. 21 CFR 630.6 - Donor notification.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... attempts to notify any donor, including an autologous donor, who has been deferred based on the results of... reasonable attempts to notify the donor. (d) Autologous donors. (1) You also must provide the following information to the referring physician of an autologous donor who is deferred based on the results of...

  5. 21 CFR 630.6 - Donor notification.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... attempts to notify any donor, including an autologous donor, who has been deferred based on the results of... reasonable attempts to notify the donor. (d) Autologous donors. (1) You also must provide the following information to the referring physician of an autologous donor who is deferred based on the results of...

  6. 21 CFR 630.6 - Donor notification.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... attempts to notify any donor, including an autologous donor, who has been deferred based on the results of... reasonable attempts to notify the donor. (d) Autologous donors. (1) You also must provide the following information to the referring physician of an autologous donor who is deferred based on the results of...

  7. 21 CFR 630.6 - Donor notification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... attempts to notify any donor, including an autologous donor, who has been deferred based on the results of... reasonable attempts to notify the donor. (d) Autologous donors. (1) You also must provide the following information to the referring physician of an autologous donor who is deferred based on the results of...

  8. Trends in Transfusion Transmitted Infections Among Replacement Blood Donors in Karachi, Pakistan

    PubMed Central

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

    2013-01-01

    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

  9. The Lombardy Rare Donor Programme

    PubMed Central

    Revelli, Nicoletta; Villa, Maria Antonietta; Paccapelo, Cinzia; Manera, Maria Cristina; Rebulla, Paolo; Migliaccio, Anna Rita; Marconi, Maurizio

    2014-01-01

    Background In 2005, the government of Lombardy, an Italian region with an ethnically varied population of approximately 9.8 million inhabitants including 250,000 blood donors, founded the Lombardy Rare Donor Programme, a regional network of 15 blood transfusion departments coordinated by the Immunohaematology Reference Laboratory of the Ca’ Granda Ospedale Maggiore Policlinico in Milan. During 2005 to 2012, Lombardy funded LORD-P with 14.1 million euros. Materials and methods During 2005–2012 the Lombardy Rare Donor Programme members developed a registry of blood donors and a bank of red blood cell units with either rare blood group phenotypes or IgA deficiency. To do this, the Immunohaematology Reference Laboratory performed extensive serological and molecular red blood cell typing in 59,738 group O or A, Rh CCDee, ccdee, ccDEE, ccDee, K− or k− donors aged 18–55 with a record of two or more blood donations, including both Caucasians and ethnic minorities. In parallel, the Immunohaematology Reference Laboratory implemented a 24/7 service of consultation, testing and distribution of rare units for anticipated or emergent transfusion needs in patients developing complex red blood cell alloimmunisation and lacking local compatible red blood cell or showing IgA deficiency. Results Red blood cell typing identified 8,747, 538 and 33 donors rare for a combination of common antigens, negative for high-frequency antigens and with a rare Rh phenotype, respectively. In June 2012, the Lombardy Rare Donor Programme frozen inventory included 1,157 red blood cell units. From March 2010 to June 2012 one IgA-deficient donor was detected among 1,941 screened donors and IgA deficiency was confirmed in four previously identified donors. From 2005 to June 2012, the Immunohaematology Reference Laboratory provided 281 complex red blood cell alloimmunisation consultations and distributed 8,008 Lombardy Rare Donor Programme red blood cell units within and outside the region, which were transfused to 2,365 patients with no untoward effects. Discussion Lombardy Rare Donor Programme, which recently joined the ISBT Working Party on Rare Donors, contributed to increase blood transfusion safety and efficacy inside and outside Lombardy. PMID:23522888

  10. [Altruism and the donor].

    PubMed

    Langlois, A

    1991-08-01

    On December 20, 1988, the government of France passed a law to protect people who voluntarily participate in biomedical research. This article makes extensive reference to a major study, titled From Biology to Ethics, by Jean Bernard, a well-respected authority in the field of bioethics. The author looks at models proposed by Bernard, as examples for health volunteers, in particular, the blood donor and the self-experimenter. To set the tone of the article, she recalls the concept of altruism, as first proposed by Auguste Comte, then makes a linkage between his philosophy and Bernard's point of view. By trial and error, in their discussions, various ethics committees and the French State Council have agreed upon what constitutes fair compensation under the law. Unlike their Canadian counterparts, medical researchers in France have free access to volunteers who are not in perfect health--e.g., the elderly, people suffering from kidney deficiency, cirrhosis of the liver, etc.--but these "experimental subjects" receive no monetary compensation. Thus, healthy and less-than-healthy volunteers do not receive equal treatment under the law. This inequity, added to the fear of what amounts to a tax on the human body and the difficulty of ensuring just compensation, is giving rise to a great deal of uncertainty. PMID:1878857

  11. Adult living donor liver imaging

    PubMed Central

    Cai, Larry; Yeh, Benjamin M.; Westphalen, Antonio C.; Roberts, John P.; Wang, Zhen J.

    2016-01-01

    Adult living donor liver transplantation (LDLT) is increasingly used for the treatment of end-stage liver disease. The three most commonly harvested grafts for LDLT are left lateral segment, left lobe, and right lobe grafts. The left lateral segment graft, which includes Couinaud’s segments II and III, is usually used for pediatric recipients or small size recipients. Most of the adult recipients need either a left or a right lobe graft. Whether a left or right lobe graft should be harvested from the donors depends on estimated graft and donor remnant liver volume, as well as biliary and vascular anatomy. Detailed preoperative assessment of the potential donor liver volumetrics, biliary and vascular anatomy, and liver parenchyma is vital to minimize risks to the donors and maximize benefits to the recipients. Computed tomography (CT) and magnetic resonance imaging (MRI) are currently the imaging modalities of choice in the preoperative evaluation of potential donors. This review provides an overview of key surgical considerations in LDLT that the radiologists must be aware of, and imaging findings on CT and MRI that the radiologists must convey to the surgeons when evaluating potential donors for LDLT. PMID:26912106

  12. Adult living donor liver imaging.

    PubMed

    Cai, Larry; Yeh, Benjamin M; Westphalen, Antonio C; Roberts, John P; Wang, Zhen J

    2016-01-01

    Adult living donor liver transplantation (LDLT) is increasingly used for the treatment of end-stage liver disease. The three most commonly harvested grafts for LDLT are left lateral segment, left lobe, and right lobe grafts. The left lateral segment graft, which includes Couinaud's segments II and III, is usually used for pediatric recipients or small size recipients. Most of the adult recipients need either a left or a right lobe graft. Whether a left or right lobe graft should be harvested from the donors depends on estimated graft and donor remnant liver volume, as well as biliary and vascular anatomy. Detailed preoperative assessment of the potential donor liver volumetrics, biliary and vascular anatomy, and liver parenchyma is vital to minimize risks to the donors and maximize benefits to the recipients. Computed tomography (CT) and magnetic resonance imaging (MRI) are currently the imaging modalities of choice in the preoperative evaluation of potential donors. This review provides an overview of key surgical considerations in LDLT that the radiologists must be aware of, and imaging findings on CT and MRI that the radiologists must convey to the surgeons when evaluating potential donors for LDLT. PMID:26912106

  13. Living kidney donors and ESRD.

    PubMed

    Ross, Lainie Friedman

    2015-07-01

    There are more than 325 living kidney donors who have developed end-stage renal disease and have been listed on the Organ Procurement and Transplantation Network (OPTN)/United Network for Organ Sharing (UNOS) deceased donor kidney wait list. The OPTN/UNOS database records where these kidney donors are listed and, if they donated after April 1994, where that donation occurred. These 2 locations are often not the same. In this commentary, I examine whether a national living donor registry should be created and whether transplantation centers should be notified when one of their living kidney donors develops end-stage renal disease. I consider and refute 5 potential objections to center notification. I explain that transplantation centers should look back at these cases and input data into a registry to attempt to identify patterns that could improve donor evaluation protocols. Creating a registry and mining the information it contains is, in my view, our moral and professional responsibility to future patients and the transplantation endeavor. As individuals and as a community, we need to acknowledge the many unknown risks of living kidney donation and take responsibility for identifying these risks. We then must share information about these risks, educate prospective donors about them, and attempt to minimize them. PMID:25936672

  14. Enzyme immunoassay for carminic acid in foods.

    PubMed

    Yoshida, A; Takagaki, Y; Nishimune, T

    1995-01-01

    A competitive enzyme immunoassay (EIA) for carminic acid was investigated. Monoclonal anticarminic acid antibody was obtained from A/J mice immunized with carminic acid-human immunoglobulin G (IgG) conjugate. Carminic acid was extracted with distilled water from beverage, jelly, candy, pasta sauce, yogurt, or ice cream samples. Ham or fish paste samples were digested with pronase, then carminic acid was extracted from samples with sodium hydroxide solution. The extract was diluted more than 10-fold with 1% gelatin in borate buffer solution. Microtiter plates were coated with carminic acid-bovine serum albumin (BSA) conjugate or just BSA. Goat anti-mouse IgG(H+L)-peroxidase complex was used as a second antibody, and 3,3',5,5'-tetramethylbenzidine was used as a substrate for the peroxidase. The working range for quantitative analysis was 0.3-10 ng/mL, and the detection limit was 0.2 micrograms/g original sample. Recoveries of carminic acid by this assay were > 95% for milk beverage and jelly, and > 85% for yogurt and fish paste. Carminic acid was detected in 7 of 26 red-colored commercial food products and ranged from 3.5 to 356 micrograms/g. This EIA system also responded to the structural analogue of carminic acid, laccaic acid. PMID:7756895

  15. Integrated optic immunoassay for virus detection

    NASA Astrophysics Data System (ADS)

    Boiarski, Anthony A.; Busch, James R.; Miller, Larry S.; Zulich, A. W.; Burans, James

    1995-05-01

    An integrated optic refractometer device was developed to perform a rapid one-step, label-free immunoassay. The device measures refractive index changes at the surface of a planar waveguide using interferometry. Antibodies were applied to the waveguide surface to provide a bioselective coating for detecting and quantifying a specific antigen of interest. The detection limit of this biosensor was determined for adenovirus as a model for other viral analytes of military, medical, and environmental interest. As binding of the antigen occurred on the sensor surface, a time-dependent phase shift of the helium-neon laser light beam was detected and was measured over a 10-minute time period. Adenovirus was detected at levels of 250 - 2500 viral particles/ml. This detection limit was obtained for a mono-layer of antibody attached to the sensor. Use of a high-density, multi-layer antibody coating approach resulted in improved detection limits for bacteria and protein analytes of general interest.

  16. Prevalence of antibodies to human immunodeficiency virus type 1 among blood donors prior to screening. The Transfusion Safety Study/NHLBI Donor Repository.

    PubMed

    Kleinman, S H; Niland, J C; Azen, S P; Operskalski, E A; Barbosa, L H; Chernoff, A I; Edwards, V M; Lenes, B A; Marshall, G J; Nemo, G J

    1989-09-01

    The Transfusion Safety Study (TSS) and the National Heart, Lung, and Blood Institute (NHLBI) established a repository of approximately 200,000 sera from blood donors in late 1984 and early 1985. Collections were made in the four metropolitan areas with the highest prevalence of AIDS. Retrospective testing showed an overall anti-HIV-1 prevalence of 16 cases per 10,000 donations. In this study, the predictive value of a negative initial enzyme-linked immunoassay was estimated from both quality control specimens and the rescreening of 13,461 sera to be greater than 99.99 percent with respect to technical error. Among anti-HIV-1-positive persons, there was a 1.3- to 1.5-fold excess of first-time donors. The anti-HIV-1 prevalence among donors showed that infection was more common among young men than suggested by national reporting of AIDS cases. Anti-HIV-1 prevalence varied among the four metropolitan areas less than did reported AIDS cases, but, by 1987, the differences in the latter had decreased. Anti-HIV-1 prevalence in collection areas outside of the four major cities differed much more widely than that among the cities themselves. The TSS/NHLBI Donor Repository will remain available for the indefinite future for further evaluation of screening procedures for HIV-1 and other viruses for which transfusion is found to be an important route of transmission. PMID:2672433

  17. Surface second-harmonic generation (SSHG): a new scheme for immunoassay

    NASA Astrophysics Data System (ADS)

    Yang, Liqun; McStay, Daniel; Quinn, Peter J.

    1996-04-01

    A new optical immunoassay scheme based on surface second harmonic generation (SHG) is proposed. The utility of the technique has been investigated by deposition of sample antigen and antibody (bovine serum albumin & mouse anti-bovine serum albumin IgG antibody) on glass surfaces. The laser-induced second harmonic signals generated from these sample surfaces were monitored using a photomultiplier tube (Thorn EMI, 9524A). The surface second harmonic generation characteristics of an enzyme-linked immunoassay process were investigated, which is parallely monitored by a conventional ELISA method. The SSHG immunoassay experiment was performed using a conventional sandwich immunoassay scheme on ELISA immunoassay plates. The laser-induced surface-second harmonic signals generated from sample wells of different populations of the antigen-antibody complex were subsequently measured using the photomultiplier tube. To verify the new SSHG immunoassay results, a conventional ELISA sandwich immunoassay was performed, and their results compared. The new SSHG immunoassay results showed a virtually identical conclusion as that of conventional ELISA sandwich immunoassay. The SSHG readings are promotional to that of the ELISA data. However, the readings from the new SSHG immunoassay were found much larger, which is in agreement with the theoretical expectation. In this paper, detailed experimental results of the new SSHG immunoassay are described, and subsequently compared with those of a conventional ELISA immunoassay. The feasibility and advantages of the SSHG as a new immunoassay technique also are discussed.

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

    PubMed Central

    Alvarado-Esquivel, Cosme; Mercado-Suarez, Miguel Francisco; Rodríguez-Briones, Alfredo; Fallad-Torres, Laura; Ayala-Ayala, Julio Octavio; Nevarez-Piedra, Luis Jorge; Duran-Morales, Ehecatl; Estrada-Martínez, Sergio; Liesenfeld, Oliver; Márquez-Conde, José Ángel; Martínez-García, Sergio Arturo

    2007-01-01

    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. PMID:17629901

  19. How to Motivate Whole Blood Donors to Become Plasma Donors

    PubMed Central

    2014-01-01

    This study tested the efficacy of interventions to recruit new plasma donors among whole blood donors. A sample of 924 donors was randomized to one of three conditions: control; information only by nurse; and information plus self-positive image message by nurse (SPI). Participants in the control condition only received a leaflet describing the plasma donation procedure. In the two experimental conditions the leaflet was explained face-to-face by a nurse. The dependent variables were the proportion of new plasma donors and the number of donations at six months. Overall, 141 (15.3%) new plasma donors were recruited at six months. There were higher proportions of new plasma donors in the two experimental conditions compared to the control condition (P < .001); the two experimental conditions did not differ. Also, compared to the control condition, those in the experimental conditions (all Ps < .001) gave plasma more often (information only by nurse:  d = .26; SPI: d = .32); the SPI intervention significantly outperformed (P < .05) the information only by nurse condition. The results suggest that references to feelings of SPI such as feeling good and being proud and that giving plasma is a rewarding personal experience favor a higher frequency of plasma donation. PMID:25530909

  20. Concentration Gradient Immunoassay I. A Rapid Immunoassay Based on Interdiffusion and Surface Binding in a Microchannel

    PubMed Central

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

    2008-01-01

    We describe a novel microfluidic immunoassay method based on the diffusion of a small molecule analyte into a parallel-flowing stream containing cognate antibody. This interdiffusion results in a steady-state gradient of antibody binding site occupancy transverse to convective flow. In contrast to the diffusion immunoassay (Hatch et al. Nature Biotechnology,19:461−465 (2001)), this antibody occupancy gradient is interrogated by a sensor surface coated with a functional analog of the analyte. Antibodies with at least one unoccupied binding site may specifically bind to this functionalized surface, leading to a quantifiable change in surface coverage by the antibody. SPR imaging is used to probe the spatial distribution of antibody binding to the surface and, therefore, the outcome of the assay. We show that the pattern of antibody binding to the SPR sensing surface correlates with the concentration of a model analyte (phenytoin) in the sample stream. Using an inexpensive disposable microfluidic device, we demonstrate assays for phenytoin ranging in concentration from 75 to 1000 nM in phosphate buffer. At a total volumetric flow rate of 90 nL/sec, the assays are complete within 10 minutes. Inclusion of an additional flow stream on the side of the antibody stream opposite to that of the sample enables simultaneous calibration of the assay. This assay method is suitable for rapid quantitative detection of low-molecular weight analytes for point-of-care diagnostic instrumentation. PMID:17437332

  1. Why Minority Donors Are Needed

    MedlinePlus

    ... Why Donate RELATED INFORMATION Minority Focused Grantee Publications Organ Donation Process Enrolling as a Donor Trying to Save ... transplantation for everyone. > More about African Americans and organ donation > More about Asians, and Native Hawaiians and other ...

  2. Being a Living Donor: Risks

    MedlinePlus

    ... for blood transfusions side effects associated with allergic reactions to the anesthesia death The best source of information about risks and expected donor outcomes is your transplant team. In addition, it’s important to take an active role in ...

  3. Capillary Isoelectric Focusing Immunoassay for Fat Cell Differentiation Proteomics

    PubMed Central

    Johlfs, Mary G.; Gorjala, Priyatham; Urasaki, Yasuyo; Le, Thuc T.; Fiscus, Ronald R.

    2015-01-01

    Profiling cellular proteome is critical to understanding signal integration during cell fate determination. In this study, the capability of capillary isoelectric focusing (cIEF) immunoassays to detect post-translational modifications (PTM) of protein isoforms is demonstrated. cIEF immunoassays exhibit protein detection sensitivity at up to 5 orders of magnitude higher than traditional methods. This detection ultra-sensitivity permits proteomic profiling of several nanograms of tissue samples. cIEF immunoassays are employed to simultaneously profile three protein kinases during fat cell differentiation: cGMP-dependent protein kinase type I (PKG-I) of the nitric oxide (NO) signaling pathway, protein kinase B (Akt) of the insulin signaling pathway, and extracellular signal-regulated kinase (ERK) of the mitogen-activated protein kinase (MAPK) signaling pathway. Interestingly, a switch in the expression level of PKG- isoforms is observed during fat cell differentiation. While both PKG-Iα and PKG-Iβ isoforms are present in preadipocytes, only PKG-Iβ isoform is expressed in adipocytes. On the other hand, the phosphorylation level increases for Akt while decreases for ERK1 and ERK2 following the maturation of preadipocytes into adipocytes. Taken together, cIEF immunoassay provides a highly sensitive means to study fat cell differentiation proteomics. cIEF immunoassay should be a powerful proteomics tool to study complex protein signal integration in biological systems. PMID:26132171

  4. Donor selection in heart transplantation

    PubMed Central

    Emani, Sitaramesh; Sai-Sudhakar, Chittoor B.; Higgins, Robert S. D.; Whitson, Bryan A.

    2014-01-01

    There is increased scrutiny on the quality in health care with particular emphasis on institutional heart transplant survival outcomes. An important aspect of successful transplantation is appropriate donor selection. We review the current guidelines as well as areas of controversy in the selection of appropriate hearts as donor organs to ensure optimal outcomes. This decision is paramount to the success of a transplant program as well as recipient survival and graft function post-transplant. PMID:25132976

  5. 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...

  6. PRNP variants in goats reduce sensitivity of detection of PrPSc by immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassays are extensively utilized in disease diagnostics with monoclonal antibodies serving as critical tools within the assay. Detection of scrapie in sheep and goats relies heavily on immunoassays including immunohistochemistry, western blotting, and ELISA. In the United States, regulatory tes...

  7. Magnetic separation and immunoassay of multi-antigen based on surface enhanced Raman spectroscopy.

    PubMed

    Chen, Shuai; Yuan, Yaxian; Yao, Jianlin; Han, Sanyang; Gu, Renao

    2011-04-14

    A novel and highly sensitive immunoassay method based on surface enhanced Raman spectroscopy (SERS) and magnetic particles has been developed. This method exhibits great potential application in bio-separation and immunoassay. PMID:21359307

  8. 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...

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

    ERIC Educational Resources Information Center

    Rugano, Emilio Kariuki

    2011-01-01

    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

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

    ERIC Educational Resources Information Center

    Rugano, Emilio Kariuki

    2011-01-01

    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…

  11. A Wash-Free Homogeneous Colorimetric Immunoassay Method

    PubMed Central

    Liu, Huiqiao; Rong, Pengfei; Jia, Hongwei; Yang, Jie; Dong, Bo; Dong, Qiong; Yang, Cejun; Hu, Pengzhi; Wang, Wei; Liu, Haitao; Liu, Dingbin

    2016-01-01

    Rapid and convenient biosensing platforms could be beneficial to timely diagnosis and treatment of diseases in virtually any care settings. Sandwich immunoassays, the most commonly used methods for protein detection, often rely on expensive tags such as enzyme and tedious wash and incubation procedures operated by skilled labor. In this report, we revolutionized traditional sandwich immunoassays by providing a wash-free homogeneous colorimetric immunoassay method without requirement of any separation steps. The proposed strategy was realized by controlling the growth of gold nanoparticles (AuNPs) to mediate the interparticle spacing in the protein-AuNP oligomers. We have demonstrated the successful in vitro detection of cancer biomarker in serum samples from patients with high clinical sensitivity and specificity. PMID:26722373

  12. Enzyme immunoassays as screening tools for catalysts and reaction discovery.

    PubMed

    Créminon, Christophe; Taran, Frédéric

    2015-05-11

    Enzyme immunoassays are incredibly powerful analytical tools for the quantifiable detection of target molecules in complex media. These techniques, which exploit the fantastic specific binding properties of antibodies, are fast, precise, selective and highly sensitive and thus perfectly adapted to high-throughput detection of important analytes. Although immunoassays have been used routinely by biologists for more than 50 years, especially for diagnostic purposes, it is only recently that chemists have used them to address pure chemical problems. In this feature article, we provide an overview of progress in the development of immunoassays and their use in two main fields of organic chemistry: the identification of efficient catalysts in libraries and the discovery of new chemical reactions. PMID:25765583

  13. A Wash-Free Homogeneous Colorimetric Immunoassay Method.

    PubMed

    Liu, Huiqiao; Rong, Pengfei; Jia, Hongwei; Yang, Jie; Dong, Bo; Dong, Qiong; Yang, Cejun; Hu, Pengzhi; Wang, Wei; Liu, Haitao; Liu, Dingbin

    2016-01-01

    Rapid and convenient biosensing platforms could be beneficial to timely diagnosis and treatment of diseases in virtually any care settings. Sandwich immunoassays, the most commonly used methods for protein detection, often rely on expensive tags such as enzyme and tedious wash and incubation procedures operated by skilled labor. In this report, we revolutionized traditional sandwich immunoassays by providing a wash-free homogeneous colorimetric immunoassay method without requirement of any separation steps. The proposed strategy was realized by controlling the growth of gold nanoparticles (AuNPs) to mediate the interparticle spacing in the protein-AuNP oligomers. We have demonstrated the successful in vitro detection of cancer biomarker in serum samples from patients with high clinical sensitivity and specificity. PMID:26722373

  14. Immunoassay for mercury in seafood and animal tissues

    SciTech Connect

    Carlson, L.; Holmquist, B.; Ladd, R.; Riddell, M.

    1995-12-01

    Methylmercury accumulates to high levels in the tissues of fish and other animals through biomagnification. Since methylmercury is extremely toxic, it is important to identify fish or animal tissues with mercury levels too high for human consumption. Current methods for the analysis of mercury are expensive and time- consuming, and they must be performed in a laboratory setting. In this study, a rapid and inexpensive mercury-specific immunoassay developed by BioNebraska was used to measure total mercury in tissue following acid digestion and methylmercury decomposition. A good correlation was obtained between the immunoassay and cold vapor atomic absorption spectrophotometry (CVAAS). Use of the mercury immunoassay will facilitate the rapid screening of large numbers of tissue samples.

  15. Analysis of Donor Motivations in Living Donor Liver Transplantation

    PubMed Central

    Abdeldayem, Hesham; Kashkoush, Samy; Hegab, Bassem Soliman; Aziz, Amr; Shoreem, Hany; Saleh, Shereef

    2014-01-01

    Objectives: The introduction of the living donor liver transplantation (LDLT) in Egypt as in elsewhere, has raised important psychological conflicts and ethical questions. The objective of this study was to get better understanding of the potential donors’ motives toward LDLT. Methods: This study was conducted on consecutive 193 living-liver donors who underwent partial hepatectomy as donors for LDLT during the period between April 2003 and January 2013, at the National Liver Institute Menoufeyia University, Egypt. Potential donors were thoroughly evaluated preoperatively through a screening questionnaire and interviews as regard their demographic data, relationship to the potential recipient, and motives toward proceeding to surgery. They were assured that the information shared between them and the transplant center is confidential. Results: The donors’ mean age was 25.53 ± 6.39 years with a range of 18–45 years. Males represented 64.7% and females were 35.3%. The most common donors (32.1%, n = 62) were sons and daughters to their parents (sons: n = 43, daughters: n = 19) while parents to their offsprings represent 15% (mothers: n = 21, fathers: n = 8). Brothers and sisters represent 16.5% (brothers: n = 22, sisters: n = 10). Nephews and nieces giving their uncles or aunts were 14%. The number of wives donating to their husbands was 11 (5.7%). Interestingly, there was no single husband who donated his wife. Among the remaining donors, there were 11 cousins and 1 uncle. Unrelated donors were 20 (10.4%). Several factors seemed to contribute to motivation for donation: the seriousness of the potential recipient condition, the relationship and personal history of the donor to the potential recipient, the religious beliefs, the trust in the health care system, and family dynamics and obligations. Conclusion: Absolute absence of coercion on the living-liver donor’s motives may not be realistic because of the serious condition of the potential recipient. It is mandatory that the donor is truly willing to donate. PMID:25593949

  16. Blood Donation by Elderly Repeat Blood Donors

    PubMed Central

    Zeiler, Thomas; Lander-Kox, Jutta; Alt, Timo

    2014-01-01

    Summary Background Upper age limits for blood donors are intended to protect elderly blood donors from donor reactions. However, due to a lack of data about adverse reactions in elderly blood donors, upper age limits are arbitrary and vary considerably between different countries. Methods Here we present data from 171,231 voluntary repeat whole blood donors beyond the age of 68 years. Results Blood donations from repeat blood donors beyond the age of 68 years increased from 2,114 in 2005 to 38,432 in 2012 (from 0,2% to 4.2% of all whole blood donations). Adverse donor reactions in repeat donors decreased with age and were lower than in the whole group (0.26%), even in donors older than 71 years (0.16%). However, from the age of 68 years, the time to complete recovery after donor reactions increased. Donor deferrals were highest in young blood donors (21.4%), but increased again in elderly blood donors beyond 71 years (12.6%). Conclusion Blood donation by regular repeat blood donors older than 71 years may be safely continued. However, due to a lack of data for donors older than 75 years, blood donation in these donors should be handled with great caution. PMID:25254019

  17. Philanthropic Motivations of Community College Donors

    ERIC Educational Resources Information Center

    Carter, Linnie S.; Duggan, Molly H.

    2011-01-01

    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…

  18. Protein microchips : use for immunoassay and enzymatic reactions.

    SciTech Connect

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

    2000-02-15

    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.

  19. Ability of TESTPACK ROTAVIRUS enzyme immunoassay to diagnose rotavirus gastroenteritis.

    PubMed Central

    Chernesky, M; Castriciano, S; Mahony, J; Spiewak, M; Schaefer, L

    1988-01-01

    TESTPACK ROTAVIRUS, a simple 10-min enzyme immunoassay, was compared with electron microscopy and Pathfinder enzyme immunoassay on feces from 172 patients of various ages with gastroenteritis. The percent sensitivities and specificities before blocking with antiserum were as follows: TESTPACK, 100% sensitivity and 99% specificity; Pathfinder, 95% sensitivity and 98% specificity. After blocking, the sensitivity and specificity, respectively, were 100% and 100% for TESTPACK and 95% and 99% for Pathfinder. TESTPACK ROTAVIRUS was more sensitive, but not significantly, than Pathfinder (P greater than 0.1) and the direct electron microscopy technique (P greater than 0.1). PMID:3069866

  20. Variability in Telavancin Cross-Reactivity among Vancomycin Immunoassays

    PubMed Central

    McConeghy, Kevin W.; Liao, Siyun; Clark, Douglas; Worboys, Philip; Barriere, Steven L.

    2014-01-01

    Telavancin is a semisynthetic lipoglycopeptide with a dual mechanism of action against Gram-positive pathogens. Two brief reports have suggested potential cross-reactivity of telavancin with the vancomycin particle-enhanced turbidometric immunoassay (PETIA). The purpose of this study was to evaluate several commercially available vancomycin immunoassays (fluorescence polarization [FPIA], enzyme-multiplied immunoassays [EMIT], PETIA, and chemiluminescent immunoassay [CMIA]) for cross-reactivity with telavancin. Seven sites were selected to analyze serum samples for vancomycin. Each site received a set of samples (n = 18) which combined drug-free serum with telavancin, 7-OH telavancin metabolite, or vancomycin. Immunoassays demonstrating potential cross-reactivity were further evaluated by sending a duplicate sample set to multiple laboratories. Cross-reactivity was defined as the percent theoretical concentration (reported concentration/theoretical concentration × 100). No cross-reactivity was seen with FPIA or EMIT. Within the theoretical concentration range of 5 to 120 μg/ml of telavancin, the Synchron PETIA system reported vancomycin concentrations ranging from 4.7 to 54.2 μg/ml compared to vancomycin concentrations from 1.1 to 5.6 μg/ml for the Vista PETIA system. The Architect CMIA system reported vancomycin concentrations in the range of 0.27 to 0.97 μg/ml, whereas Advia Centaur XP CMIA reported vancomycin concentrations between 1.6 and 31.6 μg/ml. The Architect CMIA immunoassay had the lowest percent cross-reactivity (0.8 to 5.4%), while the Synchron PETIA immunoassay demonstrated the highest percent cross-reactivity (45.2 to 53.8%). Telavancin samples measured by liquid chromatography-mass spectroscopy were within 93.9 to 122% of theoretical concentrations. Vancomycin concentrations were not measured in any 7-OH telavancin-spiked sample. Vancomycin concentrations measured by liquid chromatography-mass spectroscopy were within 57.2 to 113% of theoretical concentrations. PETIA and CMIA measured vancomycin concentrations in telavancin-spiked samples. Significant variability in percent cross-reactivity was observed for each platform regardless of immunoassay method. PMID:25223996

  1. Donor Hemovigilance with Blood Donation

    PubMed Central

    Diekamp, Ulrich; Gneißl, Johannes; Rabe, Angela; Kießig, Stephan T.

    2015-01-01

    Background Reports on unexpected events (UEs) during blood donation (BD) inadequately consider the role of 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 PMS. Medical directors reviewed entries quarterly. EBPS compiled data on donors, donations, and UEs from January 1, 2008 to June 30, 2011. Results 6,605 UEs were observed during 166,650 BDs from 57,622 donors for a corrected incidence of 4.30% (0.66% local, 1.59% systemic, 2.04% technical UEs). 2.96% of BDs were accompanied by one UE and 0.45% by >1 UE (2-4). 6.3% of donors donating blood for their first time, 3.5% of those giving blood for their second time, and 1.9% of donors giving their third or more BD experienced UEs. Most common UEs were: discontinued collections due to venous access problems, repeated venipuncture, and small hematomas. Severe circulatory UEs occurred at a rate of 16 per 100,000 BDs. Conclusions Technical UEs were common during BD. UEs accompanied first and second donations significantly more often than subsequent donations. PMID:26195932

  2. Aggressive organ donor management protocol.

    PubMed

    DuBose, Joseph; Salim, Ali

    2008-01-01

    As of August 2007, 96 900 people are awaiting organ transplantation in the United States, while only 28 930 transplants were performed in 2006. With such a large gap between organ need and organ availability, it is inevitable that many will die while awaiting transplantation. This organ shortage has become a national public health crisis, and as a response, the United States Department of Health and Human Services launched the Organ Donation Breakthrough Collaborative, an ambitious campaign to dramatically increase the number of transplantable organs. One of the suggested strategies involves maximizing the number of organs obtained from the available cadaveric "brain dead'' donor pool by using donor management protocols that optimize and treat the profound physiological disturbances that are associated with brain death. The use of these standardized and aggressive donor management protocols has been shown to increase the number of transplanted organs and prevent the number of donors lost due to medical failures. A protocol-driven approach by a dedicated organ donor management team should be considered a key component of any program designed to bridge the gap between organ supply and demand. PMID:18815202

  3. Correlation of herpes simplex virus antibody titers and specific lymphocyte stimulation in adult blood donors.

    PubMed Central

    Moser, H; Behrens, F; Ziegelmaier, R; Hilfenhaus, J; Mauler, R

    1981-01-01

    Antibody titers to herpes simplex virus type 1 in sera from healthy adult donors were assayed by complement fixation, microneutralization, and an enzyme immunoassay (ELISA). This last test proved to be the most sensitive method for antibody detection. It was estimated that ELISA antibody titers were up to 40-fold higher than neutralizing antibody titers and up to 100-fold higher than complement fixation antibody titers. Due to the higher sensitivity of ELISA, only 3 of 36 blood donors tested in this assay were shown to be seronegative, whereas 6 additional persons of the same group were termed seronegative by the microneutralization assay. Furthermore, four of the latter also did not respond in the complement fixation test. In vitro stimulation of peripheral lymphocytes by using a partially purified herpes simplex virus type 1 particle antigen was achieved for all seropositive blood donors. Only those three donors who were ELISA negative reacted negatively in this stimulation assay. From these results it may be concluded that ELISA is an appropriate method not only for rapid and sensitive antibody determination but also for selecting herpes simplex virus-negative patients. PMID:6257756

  4. Donor HLA-specific Abs: to BMT or not to BMT?

    PubMed Central

    Leffell, MS; Jones, RJ; Gladstone, DE

    2015-01-01

    The engraftment failure associated with Abs to donor-specific HLA (DSA) limits options for sensitized BMT candidates. Fourteen of fifteen patients with no other viable donor options were desensitized and transplanted using a regimen of plasmapheresis and low-dose i.v. Ig modified to accommodate pre-BMT conditioning. DSA levels were assessed by solid-phase immunoassays and cell-based crossmatch tests. DSA levels were monitored throughout desensitization and on day − 1 to determine if there was any DSA rebound that would require additional treatment. A mean reduction in DSA level of 64.4% was achieved at the end of desensitization, with a subsequent reduction of 85.5% after transplantation. DSA in 11 patients was reduced to levels considered negative post-BMT, whereas DSA in three patients remained at low levels. All 14 patients achieved donor engraftment by day +60; however, seven patients suffered disease relapses. Four patients experienced mild, grade 1 GVHD. Factors influencing the response to desensitization include initial DSA strength, number, specificity, DSA rebound and a mismatch repeated from a prior transplant. While desensitization should be reserved for patients with limited donor options, careful DSA assessment and monitoring can facilitate successful engraftment after BMT. PMID:25706884

  5. Clinical evaluation of the sensitivity and specificity of a commercially available enzyme immunoassay for detection of rubella virus-specific immunoglobulin M.

    PubMed Central

    Chernesky, M A; Wyman, L; Mahony, J B; Castriciano, S; Unger, J T; Safford, J W; Metzel, P S

    1984-01-01

    A solid-phase capture antigen enzyme immunoassay (Rubazyme-M) was evaluated for sensitivity and specificity on sera from 1,200 blood donors, 51 patients with rubella, 2 infants with congenital rubella, 104 patients with other infections, and 126 patients with immunological abnormalities. The sensitivity was 100% for sera tested between days 3 and 40 after the onset of symptoms of rubella virus infection. Rubella virus-specific immunoglobulin M was detected at birth in sera from congenitally infected infants and persisted for several months. Positive Rubazyme-M responses were observed in some patients in the absence of rubella diagnosis (one blood donor, three other infections, and two immunological abnormalities), providing a test specificity of 99.6%. None of 67 patients with rubella virus-specific immunoglobulin G antibody and high levels of rheumatoid factor were positive in the test. PMID:6386857

  6. Living donor kidney transplants: personal reflections.

    PubMed

    Najarian, John S

    2005-11-01

    Short- and long-term living kidney donor morbidity and mortality are discussed herein. The analysis includes over 3000 living donor kidney transplants from 1963 through 2002 at a single institution. The category of living donors includes living related donors, such as fathers, mothers, siblings, offspring, and other genetically related donors, as well as living unrelated donors, such as spouses, friends, or altruistic strangers. Graft and patient survival rates with living related and unrelated living donors are compared to rates with cadaveric donors. Donor risks are discussed, including short-term surgical risks as well as long-term risks of impaired renal function, possible hypertension, and psychological risks. Finally, early and late donor mortality statistics are presented. In addition, the benefits to potential donors are reviewed. Donors are carefully screened before donation. During this screening process, a significant number of donors have been found to have abnormal renal function--some had undisclosed hypertension and others had unknown cardiovascular disease. In addition, six malignancies were found, eventually resulting in curative resection. A secondary benefit to donors was reported in a study from Norway and Sweden, which showed that donors had improved long-term survival versus the general population. Our own long-term studies involving follow-up of 20 to 30 years after kidney donation have shown no significant difference in donor renal function, blood pressure, and incidence of proteinuria, as compared with their nondonor siblings. We also found donors to be perfectly normal in all other categories; several had even undergone normal pregnancies after donation. Most donors reported a high quality of life, with a boost in self-esteem and an increased sense of well-being: 96% felt it was a positive experience. In conclusion, living kidney donation has a very low mortality rate. Long-term follow-up shows minimal impact after donation. Donor quality of life is reported as excellent. PMID:16386479

  7. [The safety of blood donors].

    PubMed

    Courchelle, J; Baudry, C; Bourboul, M-C; Coudurier, N

    2011-04-01

    For a long time, safety has been patient-centred and taken for granted. Indeed, it needed a dramatic accident and the study of post-donation information for the question to be looked into again. However, under various statutory, organizational aspects and the professionalization of the staffs, safety has always accompanied the donor throughout its course of donation. Self-sufficiency is, certainly, the first mission of the Établissement Français du Sang: while we have to supply patients with sufficient blood products complying with quality criteria, we must not however forget the essential respect for the safety of the donor. PMID:21440480

  8. Anencephalic infants as organ donors.

    PubMed

    Botkin, J R

    1988-08-01

    Transplantation technology has been refined in recent years and now offers hope to pediatric patients with a variety of end stage disease processes. The lack of available donors for the smallest potential organ recipients has led to the suggestion that anencephalic infants be used as organ donors. This suggested policy is contrary to current law and raises fundamental ethical issues relating to the definition of death and the treatment of the dying. The technical issues in the potential organ supply from this source are described and the opposing ethical positions developing in this debate are discussed. PMID:3041364

  9. Utilization of Deceased Donor Kidneys to Initiate Living Donor Chains.

    PubMed

    Melcher, M L; Roberts, J P; Leichtman, A B; Roth, A E; Rees, M A

    2016-05-01

    We propose that some deceased donor (DD) kidneys be allocated to initiate nonsimultaneous extended altruistic donor chains of living donor (LD) kidney transplants to address, in part, the huge disparity between patients on the DD kidney waitlist and available donors. The use of DD kidneys for this purpose would benefit waitlisted candidates in that most patients enrolled in kidney paired donation (KPD) systems are also waitlisted for a DD kidney transplant, and receiving a kidney through the mechanism of KPD will decrease pressure on the DD pool. In addition, a LD kidney usually provides survival potential equal or superior to that of DD kidneys. If KPD chains that are initiated by a DD can end in a donation of an LD kidney to a candidate on the DD waitlist, the quality of the kidney allocated to a waitlisted patient is likely to be improved. We hypothesize that a pilot program would show a positive impact on patients of all ethnicities and blood types. PMID:26833680

  10. Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates

    DOEpatents

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

    1997-11-25

    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.

  11. Kinase Activity Studied in Living Cells Using an Immunoassay

    ERIC Educational Resources Information Center

    Bavec, Aljos?a

    2014-01-01

    This laboratory exercise demonstrates the use of an immunoassay for studying kinase enzyme activity in living cells. The advantage over the classical method, in which students have to isolate the enzyme from cell material and measure its activity in vitro, is that enzyme activity is modulated and measured in living cells, providing a more

  12. CAPILLARY ELECTROPHORESIS IMMUNOASSAY FOR 2,4-DICHLOROPHENOXYACETIC ACID

    EPA Science Inventory

    A capillary electrophoresis (CE) immunoassay format for 2,4-dichlorophenoxyacetic acid (2,4-D) is demonstrated. A fluorescent labeled 2,4-D analog competes with the analyte of interest for a finite number of binding sites provided by anti-2,4-D monoclonal antibodies. CE then pr...

  13. Manipulation of Dispersed Magnetic Beads for On-Chip Immunoassay

    NASA Astrophysics Data System (ADS)

    Ishikawa, Tomohiro; Lee, Jaesung; Miyake, Ryo

    2012-04-01

    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 µm 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.

  14. Kinase Activity Studied in Living Cells Using an Immunoassay

    ERIC Educational Resources Information Center

    Bavec, Aljos?a

    2014-01-01

    This laboratory exercise demonstrates the use of an immunoassay for studying kinase enzyme activity in living cells. The advantage over the classical method, in which students have to isolate the enzyme from cell material and measure its activity in vitro, is that enzyme activity is modulated and measured in living cells, providing a more…

  15. Effect of phenolic compounds on immunoassays of peanut allergens.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phenolic compounds (PCs) are antioxidants. Because of their health benefit, PCs may be added to some food products. Occasionally, these products may be subjected to screening for food allergens (i.e. peanuts). In this case, the screening (an immunoassay technique) may or may not be affected by the P...

  16. Enzyme linked immunoassay with stabilized polymer saccharide enzyme conjugates

    DOEpatents

    Callstrom, Matthew R.; Bednarski, Mark D.; Gruber, Patrick R.

    1997-01-01

    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.

  17. DETECTION OF NORWALK VIRUS IN STOOLS BY ENZYME IMMUNOASSAY

    EPA Science Inventory

    The development of a solid-phase microtiter enzyme immunoassay (EIA) for detection of Norwalk virus antigen in stool samples is described. The EIA was compared with a previously developed radioimmunoassay (RIA) for detection of Norwalk virus antigen in stools obtained from 30 vol...

  18. Highly sensitive homogenous chemiluminescence immunoassay using gold nanoparticles as label

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

    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 3 pg/mL, and the sensitivity was better than that of the reported AuNPs-based CL immunoassay for IgG.

  19. Monitoring Pesticides and Personal Care Chemicals in Water by Immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the increasing number and quantity of organic pollutants, regulatory authorities require implementation of rapid, reliable, and cost-effective technologies for monitoring of water quality. Immunoassays provide a simple, powerful and inexpensive method for monitoring organic contaminants in bo...

  20. General Bioluminescence Resonance Energy Transfer Homogeneous Immunoassay for Small Molecules Based on Quantum Dots.

    PubMed

    Yu, Xuezhi; Wen, Kai; Wang, Zhanhui; Zhang, Xiya; Li, Chenglong; Zhang, Suxia; Shen, Jianzhong

    2016-04-01

    Here, we describe a general bioluminescence resonance energy transfer (BRET) homogeneous immunoassay based on quantum dots (QDs) as the acceptor and Renilla luciferase (Rluc) as the donor (QD-BRET) for the determination of small molecules. The ratio of the donor-acceptor that could produce energy transfer varied in the presence of different concentrations of free enrofloxacin (ENR), an important small molecule in food safety. The calculated Förster distance (R0) was 7.86 nm. Under optimized conditions, the half-maximal inhibitory concentration (IC50) for ENR was less than 1 ng/mL and the linear range covered 4 orders of magnitude (0.023 to 25.60 ng/mL). The cross-reactivities (CRs) of seven representative fluoroquinolones (FQs) were similar to the data obtained by an enzyme-linked immunosorbent assay (ELISA). The average intra- and interassay recoveries from spiked milk of were 79.8-118.0%, and the relative standard deviations (RSDs) were less than 10%, meeting the requirement of residue detection, which was a satisfactory result. Furthermore, we compared the influence of different luciferase substrates on the performance of the assay. Considering sensitivity and stability, coelenterazine-h was the most appropriate substrate. The results from this study will enable better-informed decisions on the choice of Rluc substrate for QD-BRET systems. For the future, the QD-BRET immunosensor could easily be extended to other small molecules and thus represents a versatile strategy in food safety, the environment, clinical diagnosis, and other fields. PMID:26948147

  1. Development of an immunoassay to detect benzene adducts in hemoglobin

    SciTech Connect

    Grassman, J.A.

    1993-01-01

    The purpose of this project was to develop an immunoassay to detect the adducts formed in hemoglobin after exposure to benzene, which is known to cause bone marrow degeneration and acute myelogenous leukemia. The use of benzene-adduct detection as a biological monitoring method would permit measurement of low exposures and exposures sustained weeks earlier. The reactivity of hydroquinone, an important benzene metabolite, with blood proteins and amino acids was investigated in order to decide which antigens and analytes were likely to be suitable for immunoassay development. The second section determined the combination of benzene-metabolite and antigen need to produce an immunoassay with the requisite low detection limit and specificity. The immunoassays with the best performance were tested on hemoglobin from benzene-exposed mice. In vitro studies showed that hydroquinone efficiently formed adducts with erythrocyte membranes and hemoglobin but not with albumin. Adduction efficiency was greater in incubations using purified hemoglobin than whole blood. Cysteine accounted for 15 to 27% of the adducts formed by hydroquinone. The site of the other adducts were not identified although there was evidence that the hemoglobin heme was adducted. Adducts were found on only 1 of the 2 globin chains. Tryptic digestion of the globin failed to associate the adducts with a specific peptide. Antigens made from hydroquinone-adducted hemoglobin but not hydroquinone-adducted cysteines coupled to carrier proteins effectively elicited adduct-specific antibodies. Interference due to reactivity to hemoglobin was controlled by using uniform quantities of hemoglobin in all wells. The mid-range of the best assays were approximately 12 pmoles HQ per well. Antibodies directed toward hemoglobin adducted with the benzene metabolites phenol, catechol and 1,2,4-trihydroxybenzene were also made. The performance of the anti-1,2,4-trihydroxybenzene were suitable for quantitative immunoassays.

  2. Effect of Polymer Hydration State on In-Gel Immunoassays.

    PubMed

    Vlassakis, Julea; Herr, Amy E

    2015-11-01

    Applications as diverse as drug delivery and immunoassays require hydrogels to house high concentration macromolecular solutions. Yet, thermodynamic partitioning acts to lower the equilibrium concentration of macromolecules in the hydrogel, as compared to the surrounding liquid phase. For immunoassays that utilize a target antigen immobilized in the hydrogel, partitioning hinders introduction of detection antibody into the gel and, consequently, reduces the in-gel concentration of detection antibody, adversely impacting assay sensitivity. Recently, we developed a single-cell targeted proteomic assay with polyacrylamide gel electrophoresis of single cell lysates followed by an in-gel immunoassay. In the present work, we overcome partitioning that both limits analytical sensitivity and increases consumption of costly detection antibody by performing the immunoassay step after dehydrating the antigen-containing polyacrylamide gel. Gels are rehydrated with a solution of detection antibody. We hypothesized that matching the volume of detection antibody solution with the hydrogel water volume fraction would ensure that, at equilibrium, the detection antibody mass resides in the gel and not in the liquid surrounding the gel. Using this approach, we observe (compared with antibody incubation of hydrated gels): (i) 4-11 fold higher concentration of antibody in the dehydrated gels and in the single-cell assay (ii) higher fluorescence immunoassay signal, with up to 5-fold increases in signal-to-noise-ratio and (iii) reduced detection antibody consumption. We also find that detection antibody signal may be less well-correlated with target protein levels (GFP) using this method, suggesting a trade-off between analytical sensitivity and variation in immunoprobe signal. Our volume-matching approach for introducing macromolecular solutions to hydrogels increases the local in-gel concentration of detection antibody without requiring modification of the hydrogel structure, and thus we anticipate broad applicability to hydrogel-based assays, diagnostics, and drug delivery. PMID:26457450

  3. The Bioluminescence Resonance Energy Transfer from Firefly Luciferase to a Synthetic Dye and its Application for the Rapid Homogeneous Immunoassay of Progesterone.

    PubMed

    Smirnova, Daria V; Samsonova, Jeanne V; Ugarova, Natalia N

    2016-01-01

    The sensitive BRET system for the homogeneous immunoassay of a low-molecular weight antigen was developed using progesterone as an example. Two thermostable mutants of the Luciola mingrelica firefly luciferase (Luc)-the "red" mutant with λmax.em = 590 nm (RedLuc) and the "green" mutant with λmax.em = 550 nm (GreenLuc)-were tested as the donors. The water-soluble Alexa Fluor 610× (AF) dye was selected as the acceptor because its two absorption maxima, located at 550 and 610 nm, are close to the bioluminescence maxima of the GreenLuc and RedLuc, respectively. The methods for the synthesis of the luciferase-progesterone (Luc-Pg) conjugate and the conjugate of the dye and the polyclonal antiprogesterone antibody (AF-Ab) were developed. Both conjugates retained their functional properties, had high antigen-antibody binding activity, and demonstrated a high BRET signal. The homogeneous immunoassay system based on the BRET from the firefly luciferase to the synthetic dye was established to assay progesterone as a model antigen. Optimization of the assay conditions, the composition of the reaction mixture, and the concentrations of the donor and the acceptor made it possible to reach the minimum detectable progesterone concentration of 0.5 ng mL(-1) . PMID:26650341

  4. Physician Migration: Donor Country Impact

    ERIC Educational Resources Information Center

    Aluwihare, A. P. R.

    2005-01-01

    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…

  5. Single-Donor Leukophoretic Technique

    NASA Technical Reports Server (NTRS)

    Eberhardt, R. N.

    1977-01-01

    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.

  6. The Blood Donor Deferral Register

    PubMed Central

    Brunkhart, Donald E.; Ellis, Frank R.

    1979-01-01

    The paper will describe the American National Red Cross' national hepatitis surveillance registry known as the Donor Defferal Registry (DDR), and its implementation in the Missouri/Illinois Region. Attention will be given specially to computer structure and processing strategy, impact on the clinical incidence of hepatitis and the cost of the DDR.

  7. Documented deaths of hepatic lobe donors for living donor liver transplantation.

    PubMed

    Trotter, James F; Adam, Rene; Lo, Chung Mau; Kenison, Jeremy

    2006-10-01

    The actual risk of death in hepatic lobe donors for living donor liver transplantation (LDLT) is unknown because of the lack of a comprehensive database. In the absence of a definitive estimate of the risk of donor death, the medical literature has become replete with anecdotal reports of donor deaths, many of which cannot be substantiated. Because donor death is one of the most important outcomes of LDLT, we performed a comprehensive survey of the medical and lay literature to provide a referenced source of worldwide donor deaths. We reviewed all published articles from the medical literature on LDLT and searched the lay literature for donor deaths from 1989 to February 2006. We classified each death as "definitely," "possibly," or "unlikely" related to donor surgery. We identified 19 donor deaths (and one additional donor in a chronic vegetative state). Thirteen deaths and the vegetative donor were "definitely," 2 were "possibly," and 4 were "unlikely" related to donor surgery. The estimated rate of donor death "definitely" related to donor surgery is 0.15%. The rate of donor death which is "definitely" or "possibly" related to the donor surgery is 0.20%. This analysis provides a source document of all identifiable living liver donor deaths, provides a better estimate of donor death rate, and may provide an impetus for centers with unreported deaths to submit these outcomes to the liver transplantation community. PMID:16952175

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

    PubMed Central

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

    2014-01-01

    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

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

    PubMed Central

    2014-01-01

    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. PMID:24393298

  10. Rapid, automated, parallel quantitative immunoassays using highly integrated microfluidics and AlphaLISA

    NASA Astrophysics Data System (ADS)

    TakYu, Zeta; Guan, Huijiao; Ki Cheung, Mei; McHugh, Walker M.; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo; Fu, Jianping

    2015-06-01

    Immunoassays represent one of the most popular analytical methods for detection and quantification of biomolecules. However, conventional immunoassays such as ELISA and flow cytometry, even though providing high sensitivity and specificity and multiplexing capability, can be labor-intensive and prone to human error, making them unsuitable for standardized clinical diagnoses. Using a commercialized no-wash, homogeneous immunoassay technology (‘AlphaLISA’) in conjunction with integrated microfluidics, herein we developed a microfluidic immunoassay chip capable of rapid, automated, parallel immunoassays of microliter quantities of samples. Operation of the microfluidic immunoassay chip entailed rapid mixing and conjugation of AlphaLISA components with target analytes before quantitative imaging for analyte detections in up to eight samples simultaneously. Aspects such as fluid handling and operation, surface passivation, imaging uniformity, and detection sensitivity of the microfluidic immunoassay chip using AlphaLISA were investigated. The microfluidic immunoassay chip could detect one target analyte simultaneously for up to eight samples in 45 min with a limit of detection down to 10 pg mL-1. The microfluidic immunoassay chip was further utilized for functional immunophenotyping to examine cytokine secretion from human immune cells stimulated ex vivo. Together, the microfluidic immunoassay chip provides a promising high-throughput, high-content platform for rapid, automated, parallel quantitative immunosensing applications.

  11. Rapid, automated, parallel quantitative immunoassays using highly integrated microfluidics and AlphaLISA

    PubMed Central

    Tak For Yu, Zeta; Guan, Huijiao; Ki Cheung, Mei; McHugh, Walker M.; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo; Fu, Jianping

    2015-01-01

    Immunoassays represent one of the most popular analytical methods for detection and quantification of biomolecules. However, conventional immunoassays such as ELISA and flow cytometry, even though providing high sensitivity and specificity and multiplexing capability, can be labor-intensive and prone to human error, making them unsuitable for standardized clinical diagnoses. Using a commercialized no-wash, homogeneous immunoassay technology (‘AlphaLISA’) in conjunction with integrated microfluidics, herein we developed a microfluidic immunoassay chip capable of rapid, automated, parallel immunoassays of microliter quantities of samples. Operation of the microfluidic immunoassay chip entailed rapid mixing and conjugation of AlphaLISA components with target analytes before quantitative imaging for analyte detections in up to eight samples simultaneously. Aspects such as fluid handling and operation, surface passivation, imaging uniformity, and detection sensitivity of the microfluidic immunoassay chip using AlphaLISA were investigated. The microfluidic immunoassay chip could detect one target analyte simultaneously for up to eight samples in 45 min with a limit of detection down to 10 pg mL−1. The microfluidic immunoassay chip was further utilized for functional immunophenotyping to examine cytokine secretion from human immune cells stimulated ex vivo. Together, the microfluidic immunoassay chip provides a promising high-throughput, high-content platform for rapid, automated, parallel quantitative immunosensing applications. PMID:26074253

  12. Rapid, automated, parallel quantitative immunoassays using highly integrated microfluidics and AlphaLISA.

    PubMed

    Yu, Zeta Tak For; Guan, Huijiao; Cheung, Mei Ki; McHugh, Walker M; Cornell, Timothy T; Shanley, Thomas P; Kurabayashi, Katsuo; Fu, Jianping

    2015-01-01

    Immunoassays represent one of the most popular analytical methods for detection and quantification of biomolecules. However, conventional immunoassays such as ELISA and flow cytometry, even though providing high sensitivity and specificity and multiplexing capability, can be labor-intensive and prone to human error, making them unsuitable for standardized clinical diagnoses. Using a commercialized no-wash, homogeneous immunoassay technology ('AlphaLISA') in conjunction with integrated microfluidics, herein we developed a microfluidic immunoassay chip capable of rapid, automated, parallel immunoassays of microliter quantities of samples. Operation of the microfluidic immunoassay chip entailed rapid mixing and conjugation of AlphaLISA components with target analytes before quantitative imaging for analyte detections in up to eight samples simultaneously. Aspects such as fluid handling and operation, surface passivation, imaging uniformity, and detection sensitivity of the microfluidic immunoassay chip using AlphaLISA were investigated. The microfluidic immunoassay chip could detect one target analyte simultaneously for up to eight samples in 45 min with a limit of detection down to 10 pg mL(-1). The microfluidic immunoassay chip was further utilized for functional immunophenotyping to examine cytokine secretion from human immune cells stimulated ex vivo. Together, the microfluidic immunoassay chip provides a promising high-throughput, high-content platform for rapid, automated, parallel quantitative immunosensing applications. PMID:26074253

  13. Becoming a Blood Stem Cell Donor

    MedlinePlus

    ... total__ Find out why Close Becoming a Blood Stem Cell Donor NCIcancertopics Subscribe Subscribed Unsubscribe 361 361 Loading... ... Ever considered becoming a bone marrow or blood stem cell donor? Follow this true story of a former ...

  14. Living Kidney Donation: The Outcomes for Donors

    PubMed Central

    Ghods, A. J.

    2010-01-01

    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. PMID:25013567

  15. Monetary Compensation and Blood Donor Return: Results of a Donor Survey in Southwest Germany

    PubMed Central

    Weidmann, Christian; Schneider, Sven; Weck, Eberhard; Menzel, Dagmar; Klüter, Harald; Müller-Steinhardt, Michael

    2014-01-01

    Summary Background/Aims The aim of this study was to compare donor return patterns of non-compensated and compensated German first-time donors to assess the effect of monetary reward on donor return. Methods We conducted a retrospective analysis of a donor survey of 3,077 non-compensated and 738 compensated German first-time donors. Survey data were pooled and linked with blood donor return rates within the 1st, 2nd, and 3rd year. Logistic regression models were used to estimate differences in the probability of donor return between non-compensated and compensated donors. Results In the first 2 years following the initial donation, compensated donors were more likely to return with the odds of giving at least one further donation 1.86 (1st year) and 1.32 (2nd year) times higher for compensated donors than for non-compensated donors. In the 3rd year, there were no significant differences in donor return. Conclusion This report, which was based on two non-randomized donor samples, suggests that monetary compensation may increase the likelihood of donors returning in the first months after the initial donation. Monetary reward may therefore be used as a short-term strategy to recruit new donors. The long-term commitment, however, seems not to be affected by monetary reward, and complementary donor retention strategies are needed. PMID:25254021

  16. Designing shallow donors in diamond

    NASA Astrophysics Data System (ADS)

    Moussa, Jonathan

    2015-03-01

    The production of n-type semiconducting diamond has been a long-standing experimental challenge. The first-principles simulation of shallow dopants in semiconductors has been a long-standing theoretical challenge. A desirable theoretical goal is to identify impurities that will act as shallow donors in diamond and assess their experimental viability. I will discuss this identification process for the LiN4 donor complex. It builds a scientific argument from several models and computational results in the absence of computational tools that are both trustworthy and computationally tractable for this task. I will compare the theoretical assessment of viability with recent experimental efforts to co-dope diamond with lithium and nitrogen. Finally, I discuss the computational tools needed to facilitate future work on this problem and some preliminary simulations of donors near diamond surfaces. Sandia National Laboratories is a multi-program lab managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  17. A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

  18. Field screening for aldrin in soil by immunoassay

    SciTech Connect

    McCain, R.G.; Myers, M.L.

    1994-08-01

    A number of 5-gal cans labeled {open_quotes}aldrin{close_quotes} were found dumped in an isolated area near the boundary of the Hanford Site. Initial laboratory analysis showed high concentrations of aldrin in the soil directly beneath the cans. The site was included in an expedited response action (ERA) undertaken to clean up a large area along the western margin of the Hanford Site. A commercially available immunoassay test kit was modified to screen for aldrin in soil at an action level of 2 mg/kg. Field tests carried out as the contaminated soil was removed showed that the contamination extended significantly deeper than originally anticipated. The field immunoassay provided the cleanup crew with rapid turnaround results, which were used to guide the cleanup activity.

  19. Design and Fabrication of a PDMS Microchip Based Immunoassay

    SciTech Connect

    Shao, Guocheng; Wang, Wanjun; Wang, Jun; Lin, Yuehe

    2010-07-01

    In this paper, we describe the design and fabrication process of a polydimethylsiloxane (PDMS) microchip for on-chip multiplex immunoassay application. The microchip consists of a PDMS microfluidic channel layer and a micro pneumatic valve control layer. By selectively pressurizing the pneumatic microvalves, immuno reagents were controlled to flow and react in certain fluidic channel sites. Cross contamination was prevented by tightly closed valves. Our design was proposed to utilize PDMS micro channel surface as the solid phase immunoassay substrate and simultaneously detect four targets antigens on chip. Experiment result shows that 20psi valve pressure is sufficient to tightly close a 200m wide micro channel with flow rate up to 20l/min.

  20. Urinary microalbumin measurement using a homogeneous liposomal immunoassay.

    PubMed

    Frost, S J; Chakraborty, J; Firth, G B

    1996-08-14

    A homogeneous colorimetric immunoassay which has been developed for urinary microalbumin utilizes complement-mediated immunolysis of liposomes containing the dye, sulphorhodamine B. Unlike a previously described model complement-mediated liposomal assay for serum albumin (Frost et al., 1994) which was competitive, this assay uses a sandwich-type format and Fab' (antialbumin)-coated liposomes to increase the assay sensitivity. The liposomal assay, performed using a Cobas Bio analyser (Roche, Welwyn Garden City, UK), gave an acceptable correlation with a radioimmunoassay (NETRIA, London, UK): r = 0.94; y (liposomal assay) = 1.09 x (radioimmunoassay) - 1.54 mg/1. The imprecisions of the assays were similar and matrix effects due to the use of urine samples were determined to be acceptably small. The assay demonstrates the advantage of using Fab'-coated liposomes in sandwich-type liposomal immunoassays over liposomes coated with intact antibody, which failed to elicit complement-mediated immunolysis. PMID:8765163

  1. A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics.

    PubMed

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

    2011-06-01

    A novel, centrifugal disk-based micro-total analysis system (μTAS) 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. PMID:21721711

  2. A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics

    PubMed Central

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

    2011-01-01

    A novel, centrifugal disk-based micro-total analysis system (μTAS) 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. PMID:21721711

  3. Silver and gold enhancement methods for lateral flow immunoassays.

    PubMed

    Rodrguez, Myriam Oliveira; Covin, Luca Blanco; Garca, Agustn Costa; Blanco-Lpez, Maria Carmen

    2016-02-01

    Sensitivity is the main concern at the development of rapid test by lateral flow immunoassays. On the other hand, low limits of detection are often required at medical diagnostics and other field of analysis. To overcome this drawback, several enhancement protocols have been described. In this paper, we have selected different silver enhancement methods and one dual gold conjugation, and we critically compared the amplification produced when applied to a gold-nanoparticle based lateral flow immunoassay for the detection of prostate specific antigen (PSA). The highest amplification was obtained by using an immersion method based on a solution of silver nitrate and hydroquinone/citrate buffer in proportion 1:1. Under these conditions, the system is capable of detecting PSA within 20min at levels as low as 0.1ng/mL, with a 3-fold sensitivity improvement. PMID:26653449

  4. Assessment of immunoglobulin M enzyme immunoassays for diagnosis of measles.

    PubMed

    Tipples, Graham A; Hamkar, Rasool; Mohktari-Azad, Talat; Gray, Michael; Parkyn, Geoff; Head, Carol; Ratnam, Samuel

    2003-10-01

    We evaluated the performance of three commercial measles immunoglobulin M enzyme immunoassays from Meddens, Denka Seiken, and Behring. The sensitivities were determined to be 96.7% for the Meddens and Denka Seiken assays and 87.9% for the Behring assay. The specificities of the assays were determined to be 94.6% for Meddens, 98.2% for Denka Seiken, and 98.7% for Behring. PMID:14532222

  5. Acoustofluidics 21: ultrasound-enhanced immunoassays and particle sensors.

    PubMed

    Wiklund, Martin; Radel, Stefan; Hawkes, Jeremy J

    2013-01-01

    In part 21 of the tutorial series "Acoustofluidics--exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation", we review applications of ultrasonic standing waves used for enhancing immunoassays and particle sensors. The paper covers ultrasonic enhancement of bead-based immuno-agglutination assays, bead-based immuno-fluorescence assays, vibrational spectroscopy sensors and cell deposition on a sensor surface. PMID:23138938

  6. Cooperative Immunoassays: Ultrasensitive Assays with Mixed Monoclonal Antibodies

    NASA Astrophysics Data System (ADS)

    Ehrlich, Paul H.; Moyle, William R.

    1983-07-01

    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.

  7. Multianalyte microspot immunoassay. The microanalytical 'compact disk' of the future.

    PubMed

    Ekins, R; Chu, F

    1992-01-01

    Throughout the 1970s, controversy centered both on immunoassay 'sensitivity' per se and on the relative sensitivities of labelled antibody and labelled analyte methods. Our own theoretical studies in this period revealed that radioimmunoassay (RIA) sensitivities could be surpassed only by the use of very high specific activity non-isotopic labels in 'non-competitive' designs, preferably based on the use of monoclonal antibodies. The time-resolved fluorescence methodology known as Delfia - developed in collaboration with the instrument manufacturer LKB/Wallac - represented the first commercial 'ultra-sensitive' non-isotopic technique based on these theoretical insights, the same concepts being subsequently adopted in comparable methodologies relying on the use of chemiluminescent and enzyme labels. However, a second advantage of high specific activity labels is that they permit the development of 'multi-analyte' immunoassay systems combining ultra-sensitivity with the simultaneous measurement of tens, hundreds or thousands of analytes in a small biological sample. This possibility relies on simple, albeit hitherto unexploited, physicochemical concepts. The first is that all immunoassays rely on measurement of Ab occupancy by analyte. The second is that, provided the Ab concentration used is 'vanishingly small', fractional Ab occupancy is independent of both Ab concentration and sample volume. This leads to the notion of 'ratiometric' immunoassay, involving measurement of the ratio of signals (eg fluorescent signals) emitted by two labelled Ab's, the first ('sensor' Ab) deposited as a microspot on a solid support, the second a 'developing' Ab directed against either occupied or unoccupied sensor Ab binding sites.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1485691

  8. Benzene-RISc: The development and performance of an immunoassay to detect benzene in water

    SciTech Connect

    Friedman, S.B.; Withers, T.; Almond, R.; Stewart, T.; Allen, R.L.

    1994-12-31

    Immunoassay methods have become available for environmental applications. Their simplicity, reliability, and ability to provide information rapidly and on-site is enhancing the efficiency of many field and laboratory programs. Immunoassay methods rely upon antibody molecules to provide the sensitivity and specificity characteristics they exhibit, but many molecules are either insufficiently immunogenic or structurally unremarkable to induce an appropriate antibody response. Such compounds are usually considered to be incompatible with the development of an immunoassay method. An immunoassay method for the detection of benzene in water would have utility in detecting contamination from spills and leaking underground storage tanks. Benzene, however, is frequently considered to be in the class of compounds considered to be incompatible with antibody, and therefore immunoassay, development. The authors have developed an immunoassay for the detection of benzene in water by developing both sample processing and immunochemical procedures and reagents that overcome the technical limitations frequently encountered.

  9. Setting cutoff concentrations for immunoassay screening of postmortem blood.

    PubMed

    Collison, I B; Spiehler, V R; Guluzian, S; Sedgwick, P R

    1998-03-01

    The objective of this study was to establish the optimum immunoassay cutoff concentrations for screening postmortem blood from coroner's cases for drugs of abuse with a coated tube radioimmunoassay (RIA) to ensure that the results with the coated tube RIA would be equal to or better than those with the previously used double antibody RIA. Immunoassay results (positive or negative) blood were compared to confirmed results on those cases by GC/MS alone or in combination with GLC using either a NPD or FID detector. Four to seven potential cutoff concentrations were evaluated for the drug classes opiates, amphetamines, cocaine and metabolites, and barbiturates. Specimens were 350 postmortem blood specimens and liver homogenates. The cutoffs chosen for the coated tube RIA using this approach were 5 ng/mL morphine, 25 ng/mL methamphetamine, 500 ng/mL benzoylecgonine, and 500 ng/mL secobarbital. These cutoffs corresponded to a sensitivity and specificity of 94% and 96% for opiates, 93% and 86% for amphetamines, 91% and 96% for cocaine and metabolites and 91% and 87% for barbiturates. The double antibody RIAs were run on the same specimens with cutoffs of 20 ng/mL morphine, 50 ng/mL methamphetamine, 50 ng/mL benzoylecgonine and 1000 ng/mL phenobarbital. The sensitivity and specificity's for the double antibody immunoassay were: > 99% and 96% for opiates, 83% and 89% for amphetamines, 98% and 97% for cocaine, 79% and 95% for barbiturates. PMID:9544549

  10. Specific Noncompetitive Immunoassay for HT-2 Mycotoxin Detection.

    PubMed

    Arola, Henri O; Tullila, Antti; Kiljunen, Harri; Campbell, Katrina; Siitari, Harri; Nevanen, Tarja K

    2016-02-16

    Here we demonstrate a novel homogeneous one-step immunoassay, utilizing a pair of recombinant antibody antigen-binding fragments (Fab), that is specific for HT-2 toxin and has a positive readout. Advantages over the conventional competitive immunoassay formats such as enzyme-linked immunosorbent assay (ELISA) are the specificity, speed, and simplicity of the assay. Recombinant antibody HT2-10 Fab recognizing both HT-2 and T-2 toxins was developed from a phage display antibody library containing 6 × 10(7) different antibody clones. Specificity of the immunoassay was introduced by an anti-immune complex (IC) antibody binding the primary antibody-HT-2 toxin complex. When the noncompetitive immune complex assay was compared to the traditional competitive assay, an over 10-fold improvement in sensitivity was observed. Although the HT2-10 antibody has 100% cross-reactivity for HT-2 and T-2 toxins, the immune complex assay is highly specific for HT-2 alone. The assay performance with real samples was evaluated using naturally contaminated wheat reference material. The half-maximal effective concentration (EC50) value of the time-resolved fluorescence resonance energy transfer (TR-FRET) assay was 9.6 ng/mL, and the limit of detection (LOD) was 0.38 ng/mL (19 μg/kg). The labeled antibodies can be predried to the assay vials, e.g., microtiter plate wells, and readout is ready in 10 min after the sample application. PMID:26785138

  11. Multiplex Electrochemical Immunoassay Using Gold Nanoparticle Probes and Immunochromatographic Strips

    SciTech Connect

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

    2008-10-20

    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.

  12. Development of immunoassays for detecting clothianidin residue in agricultural products.

    PubMed

    Li, Ming; Sheng, Enze; Cong, Lujing; Wang, Minghua

    2013-04-17

    Two enzyme-linked immunosorbent assays (ELISAs) based on polyclonal antibodies (PcAbs) for clothianidin are described: colorimetric detection format (ELISA) and pattern of chemiluminescent assay (CLEIA). Clothianidin hapten was synthesized and conjugated to bovine serum albumin (BSA) and ovalbumin (OVA) to produce immunogen and coating antigen. Anticlothianidin PcAbs were obtained from immunized New Zealand white rabbits. Under optimal conditions, the half-maximal inhibition concentration (IC₅₀) and the limit of detection (LOD, IC₂₀) of clothianidin were 0.046 and 0.0028 mg/L for the ELISA and 0.015 and 0.0014 mg/L for the CLEIA, respectively. There were no obvious cross-reactivities of the antibodies with its analogues except for dinotefuran. Recoveries of 76.4-116.4% for the immunoassays were achieved from spiked samples. The results of immunoassays for the spiked and authentic samples were largely consistent with gas chromatography. Therefore, the proposed immunoassays would be convenient and satisfactory analytical methods for the monitoring of clothianidin in agricultural products. PMID:23527939

  13. Rapid determination of dioxin in water by enzyme immunoassay

    SciTech Connect

    Wang, H.; Wang, L.; George J.E. III; Ward, G.K.

    1996-10-01

    Dioxin in water, soil, sediments and other sample matrices is usually determined by the EPA method 1613 which was developed by the EPA Office of Science and Technology. This method however requires expensive instruments (high resolution gas chromatography/high resolution mass spectrometry) and a highly trained analyst. In order to reduce the cost and turn around time, a dioxin enzyme immunoassay (EIA) was developed to rapidly analyze trace levels of 2,3,7,8-tetra chlorinated dibenzodioxin (TCDD) in water samples. Water samples were extracted using a 47 mm, C18 Empore extraction disk (3M). Dioxin was eluted with dichloromethame. EnvironGard reagents and microwell strip reader (Millipore Corporation) were used to perform the dioxin enzyme immunoassay. The extraction efficiency was also tested by GC/MS with Varian`s large volume injector and Selected Ion Storage technique. The working range of the dioxin enzyme immunoassay was from 15 pg/L to 100 pg/L. The precision and accuracy of EIA was determined by performing five replicates of reagent water spiked at a concentration of 25 pg/L. The recovery of the dioxin assay ranged from 74% to 122%, and % CV for five replicates was less than 15%. In general, EIA provides a relatively easy and cost effective means for measuring trace levels of dioxin in water samples.

  14. An embedded microretroreflector-based microfluidic immunoassay platform.

    PubMed

    Raja, Balakrishnan; Pascente, Carmen; Knoop, Jennifer; Shakarisaz, David; Sherlock, Tim; Kemper, Steven; Kourentzi, Katerina; Renzi, Ronald F; Hatch, Anson V; Olano, Juan; Peng, Bi-Hung; Ruchhoeft, Paul; Willson, Richard

    2016-04-26

    We present a microfluidic immunoassay platform based on the use of linear microretroreflectors embedded in a transparent polymer layer as an optical sensing surface, and micron-sized magnetic particles as light-blocking labels. Retroreflectors return light directly to its source and are highly detectable using inexpensive optics. The analyte is immuno-magnetically pre-concentrated from a sample and then captured on an antibody-modified microfluidic substrate comprised of embedded microretroreflectors, thereby blocking reflected light. Fluidic force discrimination is used to increase specificity of the assay, following which a difference imaging algorithm that can see single 3 μm magnetic particles without optical calibration is used to detect and quantify signal intensity from each sub-array of retroreflectors. We demonstrate the utility of embedded microretroreflectors as a new sensing modality through a proof-of-concept immunoassay for a small, obligate intracellular bacterial pathogen, Rickettsia conorii, the causative agent of Mediterranean Spotted Fever. The combination of large sensing area, optimized surface chemistry and microfluidic protocols, automated image capture and analysis, and high sensitivity of the difference imaging results in a sensitive immunoassay with a limit of detection of roughly 4000 R. conorii per mL. PMID:27025227

  15. History of inductively coupled plasma mass spectrometry-based immunoassays

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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.

  16. Enzyme immunoassay for the detection of group A streptococcal antigen.

    PubMed Central

    Knigge, K M; Babb, J L; Firca, J R; Ancell, K; Bloomster, T G; Marchlewicz, B A

    1984-01-01

    A competitive inhibition enzyme immunoassay for the detection of Streptococcus pyogenes directly from throat specimens or from solid bacteriological medium is described. Group A-specific polysaccharide adsorbed onto treated polystyrene beads, in conjunction with rabbit antibody to S. pyogenes, was used to determine the presence of the polysaccharide antigen. Inhibition values in excess of 65% were observed with 10(4) or more CFU of S. pyogenes per test. An inhibition of 25% was demonstrated with as few as 10(3) CFU per test. Heterologous microorganisms tested at 10(6) CFU per test reacted at levels of inhibition less than 25%. Two types of bacterial transport medium and swabs of different fiber compositions did not alter the assay performance. Accurate identification of S. pyogenes was achieved by testing single colonies picked directly from blood agar plates which had been incubated for 18 to 24 h. In addition, the assay was performed on throat specimens from children and adults having pharyngitis. A single-swab, blind study was conducted in which enzyme immunoassay reactivity was compared with results of blood agar culture and bacitracin sensitivity. When there were discordant results, serological identification was used as the confirmatory test. At an optimal cutoff value of 40% inhibition, sensitivity and specificity by enzyme immunoassay were 97.0% and 97.9%, respectively, as compared with confirmed culture results. The assay has an incubation time of 3 h and is a sensitive and specific method for the detection of S. pyogenes antigen. PMID:6386878

  17. Enhancing immunoassay possibilities using magnetic carriers in biological fluids

    NASA Astrophysics Data System (ADS)

    Yu, Hao

    1997-05-01

    An antibody-based magnetic plate chemifluorescent immunoassay (MPFIA) for effective and rapid detection of bacteria and toxoid from biological fluids was developed. Streptavidin (SA)- magnetic particles and biotinylated antibody as a solid phase immunomagnetic carrier was used for antigen capture. An alkaline phosphatase-antibody conjugate as a secondary capture antibody to the antigen forms a sandwich with the primary antibody. The fluorgenic substrate, AttoPhos reacts with alkaline phosphatase that emits chemifluorescent intensities are proportional to captured antigens. Antigen separation and concentration from biological fluids using immunomagnetic carrier are the key step to reduce media interference for sensitive detection. Results of these efforts may actually enhance the immunoassay possibilities by concentration of specific antigen and reduction of background noise. Magnetic separation and chemifluorescent detection have been achieved by a multiple-well formatted magnetic plate separator and a fluorescent plate detector, respectively. Experiments were performed for virulent Escherichia coli cells, Staphylococcal enterotoxin B toxoid and Bacillus subtilus spore detection in biological fluids. In general, the fluorescent detection can be achieved at the same sensitivities as enzyme-linked immunoassay and the ECL detection is more sensitive than fluorescent assay. However, the unique features of MPFIA and MPECL are that the biological samples can be rapidly processed and detected on the same multiple sample formatted plate within one hour assay time.

  18. Single step nanoplasmonic immunoassay for the measurement of protein biomarkers.

    PubMed

    Prabhulkar, Shradha; de la Zerda, Adam; Paranjape, Amit; Awdeh, Richard M

    2013-03-01

    A nanoplasmonic biosensor for highly-sensitive, single-step detection of protein biomarkers is presented. The principle is based on the utilization of the optical scattering properties of gold nanorods (GNRs) conjugated to bio-recognition molecules. The nanoplasmonic properties of the GNRs were utilized to detect proteins using near-infrared light interferometry. We show that the antibody-conjugated GNRs can specifically bind to our model analyte, Glucose Transporter-1 (Glut-1). The signal intensity of back-scattered light from the GNRs bound after incubation, correlated well to the Glut-1 concentration as per the calibration curve. The detection range using this nanoplasmonic immunoassay ranges from 10 ng/mL to 1 ug/mL for Glut-1. The minimal detectable concentration based on the lowest discernable concentration from zero is 10 ng/mL. This nanoplasmonic immunoassay can act as a simple, selective, sensitive strategy for effective disease diagnosis. It offers advantages such as wide detection range, increased speed of analysis (due to fewer incubation/washing steps), and no label development as compared to traditional immunoassay techniques. Our future goal is to incorporate this detection strategy onto a microfluidic platform to be used as a point-of-care diagnostic tool. PMID:25587399

  19. One-sample measurement in laser nephelometric immunoassay using magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Yang, S. Y.; Wu, R. M.; Jian, Z. F.; Horng, H. E.; Hong, Chin-Yih; Yang, H. C.

    2006-12-01

    In contrast to the type of two-sample measurement used in conventional nephelometric immunoassay, a methodology to achieve a one-sample nephelometric immunoassay is developed in this work. Magnetic nanoparticles instead of latex particles are used as scattering centers. The experimental results show that the sensitivity of assaying avidin or c-reactive protein increased about three times under the action of the magnetic field in nephelometric immunoassay using magnetic nanoparticles.

  20. Idiometric assay, the third way: a noncompetitive immunoassay for small molecules.

    PubMed

    Barnard, G; Karsiliyan, H; Kohen, F

    1991-12-01

    A novel, noncompetitive immunoassay applicable to the measurement of small molecules including ovarian steroids is described. Using monoclonal antibodies with the ability to recognize both beta-typic and alpha-typic binding sites, a new simplified, sensitive, and specific immunoassay system has been developed. The initial work of this development is presented, along with preliminary results for a novel immunoassay for estradiol. PMID:1755457

  1. Is laparoscopic live donor hepatectomy justified ethically?

    PubMed

    Soubrane, Olivier; Gateau, Valérie; Lefève, Céline

    2016-04-01

    Live donor liver transplant (LDLT) was first reported in the 1990s and quickly raised ethical considerations, mainly related to the risk brought to the donor. The question of donor safety was even more accurate with the occurrence of laparoscopy, a technique which could allegedly increase the risk of severe intraoperative complications. Besides the questions of justice and autonomy, donor safety remains the main ethical debate of LDLT. Considering the lack of comparative assessment of postoperative outcomes, the Jury of the last Consensus meeting held in Japan in 2014 called for the creation of international registries to help to determine the benefit/risk ratio of laparoscopic donor hepatectomy. Since randomized studies are very unlikely to occur, benchmarking comparisons, between liver and kidney donors for instance, may also help to define standard practice. At last, donors' points of view should also be taken into account in the evaluation of those innovative procedures. PMID:26890536

  2. Kidney Transplantation From Donors with Hepatitis B.

    PubMed

    Veroux, Massimiliano; Ardita, Vincenzo; Corona, Daniela; Giaquinta, Alessia; Ekser, Burcin; Sinagra, Nunziata; Zerbo, Domenico; Patanè, Marco; Gozzo, Cecilia; Veroux, Pierfrancesco

    2016-01-01

    The growing demand for organ donors to supply the increasing number of patients on kidney waiting lists has led most transplant centers to develop protocols that allow safe use of organs from donors with special clinical situations previously regarded as contraindications. Deceased donors with previous hepatitis B may be a safe resource to increase the donor pool even if there is still controversy among transplantation centers regarding the use of hepatitis B surface antigen-positive donors for renal transplantation. However, when allocated to serology-matched recipients, kidney transplantation from donors with hepatitis B may result in excellent short-term outcome. Many concerns may arise in the long-term outcome, and studies must address the evaluation of the progression of liver disease and the rate of reactivation of liver disease in the recipients. Accurate selection and matching of both donor and recipient and correct post-transplant management are needed to achieve satisfactory long-term outcomes. PMID:27123988

  3. Simulation shows that HLA-matched stem cell donors can remain unidentified in donor searches

    PubMed Central

    Sauter, Jürgen; Solloch, Ute V.; Giani, Anette S.; Hofmann, Jan A.; Schmidt, Alexander H.

    2016-01-01

    The heterogeneous nature of HLA information in real-life stem cell donor registries may hamper unrelated donor searches. It is even possible that fully HLA-matched donors with incomplete HLA information are not identified. In our simulation study, we estimated the probability of these unnecessarily failed donor searches. For that purpose, we carried out donor searches in several virtual donor registries. The registries differed by size, composition with respect to HLA typing levels, and genetic diversity. When up to three virtual HLA typing requests were allowed within donor searches, the share of unnecessarily failed donor searches ranged from 1.19% to 4.13%, thus indicating that non-identification of completely HLA-matched stem cell donors is a problem of practical relevance. The following donor registry characteristics were positively correlated with the share of unnecessarily failed donor searches: large registry size, high genetic diversity, and, most strongly correlated, large fraction of registered donors with incomplete HLA typing. Increasing the number of virtual HLA typing requests within donor searches up to ten had a smaller effect. It follows that the problem of donor non-identification can be substantially reduced by complete high-resolution HLA typing of potential donors. PMID:26876789

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

    PubMed

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

    2013-05-01

    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

  5. Improvement of sensitivity of multisample biological immunoassay system using HTS SQUID and magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Tsukamoto, A.; Saitoh, K.; Sugita, N.; Kuma, H.; Sugiura, Y.; Hamaoka, S.; Hamasaki, N.; Enpuku, K.

    2006-10-01

    Recently, we have developed a prototype magnetic immunoassay system using a high temperature superconductor (HTS) superconducting quantum interference device (SQUID) to investigate the performance and usability of the magnetic immunoassay. In this study, we improved the immunoassay system to heighten the sensitivity of the immunoassay measurement. To reduce the SQUID-to-sample distance, we introduced a structure to compensate for thermal shrinkage in the cryostat and reduce the warpage of the window. The shape of pickup coil was also optimized to improve the field sensitivity. After these improvements, the magnetic signal intensity from Fe3O4 nanoparticles became about two times stronger than that achieved by our original system.

  6. Multicenter Analytical Evaluation of the Automated Electrochemiluminescence Immunoassay for Cyclosporine

    PubMed Central

    Vogeser, Michael; Shipkova, Maria; Rigo-Bonnin, Raül; Wallemacq, Pierre; Orth, Matthias; Widmann, Monika

    2014-01-01

    Background: Cyclosporine A (CsA) is used as a posttransplantation immunosuppressant drug, and careful monitoring of CsA concentration in whole blood is essential. A new automated electrochemiluminescence immunoassay (ECLIA) for CsA measurement has been assessed in a multicenter evaluation. Methods: Residual EDTA whole blood samples from patients undergoing CsA therapy after organ transplant were used in assay evaluation at 5 clinical laboratories in Europe. Experiments included imprecision according to CLSI EP5-A2 (within-run and intermediate), lower limit of quantification, linearity according to CLSI EP6-A, and recovery of commercial external quality control samples. In addition, comparisons to liquid chromatography-tandem mass spectrometry methods in routine use at each investigational site and to commercial chemiluminescent microparticle immunoassay and antibody-conjugated magnetic immunoassay methods were performed. Results: Imprecision testing gave coefficients of variation of less than 9% in the 30–2000 mcg/L range for both within-run and intermediate imprecision. Lower limit of quantification of 6.8 mcg/L at one investigational site and 1.8 mcg/L at a second site at 20% coefficient of variation were observed. Linearity was measured over the concentration range 0–2000 mcg/L, yielding a deviation of less than ±12%. External quality control sample recovery by ECLIA was 93%–114% of LC-MS/MS sample recovery. Deming regression analysis of ECLIA method comparison to combined LC-MS/MS results yielded a slope of 1.04 [95% confidence interval (CI), 1.03–1.06] and intercept of 2.8 mcg/L (95% CI, 1.5–4.1 mcg/L). Comparison to chemiluminescent microparticle immunoassay yielded a slope of 0.87 (95% CI, 0.85–0.89) and intercept of 1.4 mcg/L (95% CI, −0.89 to 3.7 mcg/L); comparison to antibody-conjugated magnetic immunoassay yielded a slope of 0.96 (95% CI, 0.93–0.98) and intercept of −4.2 mcg/L (95% CI, −7.1 to −1.2 mcg/L). Conclusions: The data from this multicenter evaluation indicate that the new ECLIA-based cyclosporine assay is fit for its purpose, the therapeutic monitoring of CsA. PMID:24646730

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

    PubMed

    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

    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

  8. Exxon donor solvent liquefaction process

    NASA Astrophysics Data System (ADS)

    Neavel, R. C.

    1981-03-01

    The Exxon donor solvent (EDS) coal liquefaction system is a direct liquefaction procedure. Coal is chemically reacted and dissolved in a recycle solvent that is hydrogenated between passes to the liquefaction reactor. More than 2.6 barrels of a synthetic crude boiling below 1000 F are produced per ton of dry, high volatile coal feed. Other ranks of coal can be effectively liquefied. The process development has proceeded to a 250 ton/day pilot plant stage that went into operation in June 1980. The presentation addresses the chemical reactions and process conditions that result in ease of operability and flexibility of the EDS process.

  9. Donor free radical explosive composition

    DOEpatents

    Walker, Franklin E. [15 Way Points Rd., Danville, CA 94526; Wasley, Richard J. [4290 Colgate Way, Livermore, CA 94550

    1980-04-01

    An improved explosive composition is disclosed and comprises a major portion of an explosive having a detonation velocity between about 1500 and 10,000 meters per second and a minor amount of a donor additive comprising an organic compound or mixture of organic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and which is not an explosive, or an inorganic compound or mixture of inorganic compounds capable of releasing low molecular weight free radicals or ions under mechanical or electrical shock conditions and selected from ammonium or alkali metal persulfates.

  10. Enzyme immunoassay using native envelope glycoprotein (gp160) for detection of human immunodeficiency virus type 1 antibodies.

    PubMed Central

    Nair, B C; Ford, G; Kalyanaraman, V S; Zafari, M; Fang, C; Sarngadharan, M G

    1994-01-01

    An enzyme immunoassay using the purified native gp160 for the detection of human immunodeficiency virus type 1 (HIV-1) antibody was developed. This assay was determined to be highly specific, since (i) 157 serum samples that were confirmed negative by Western blot (immunoblot) (WB) were negative, (ii) 41 serum samples from populations with medical conditions that might cause nonspecific assay reactivity were all negative, and (iii) all 15 serum samples that showed false-positive reactions in one or more commercial HIV-1 screening tests were negative. The assay gave 100% specificity with a randomly selected and unlinked panel of 1,000 serum samples from healthy blood donors. The sensitivity of the assay was assessed by testing 238 samples confirmed as HIV-1 antibody positive by a standardized WB assay. All 238 serum samples (100%) were reactive in the native gp160 assay. In a dilution panel of 14 weakly WB-positive serum samples, 7 samples reacted two-to fivefold more strongly in the gp160 assay than in a virus lysate-based assay; the remaining 7 samples gave comparable reactivities in the two tests. The reactivities of 13 of these 14 serum samples in the gp160 assay were higher than in a commercial enzyme immunoassay that uses a recombinant envelope protein as the antigen. The native gp160 assay was more sensitive to identify seroconversion. In a well-characterized panel of sequential blood samples from a seroconverter, the new assay detected antibodies at least one sample ahead of the other commercial assays tested. PMID:8077388

  11. Control of charge transfer by conformational and electronic effects: Donor-donor and donor-acceptor phenyl pyrroles

    NASA Astrophysics Data System (ADS)

    Neubauer, Antje; Bendig, Jürgen; Rettig, Wolfgang

    2009-04-01

    Derivatives of N-pyrrolobenzene with a para-donor and a para-acceptor substituent on the benzene ring are compared. It is shown that by a suitable increase of the donor strength of the pyrrolo group, CT fluorescence can be achieved even for donor-donor-substituted benzenes. The ICT emission for sterically hindered compounds is more forbidden than that of unhindered phenyl pyrroles. This suggests conformational effects which induce a narrower twist angle distribution around a perpendicular minimum in the excited state.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24549216

  13. A versatile platform for highly sensitive detection of protein: DNA enriching magnetic nanoparticles based rolling circle amplification immunoassay.

    PubMed

    Xue, Qingwang; Wang, Lei; Jiang, Wei

    2012-04-25

    A novel rolling circle amplification (RCA) immunoassay based on DNA enriching magnetic nanoparticles and assembled fluorescent DNA nanotags, magnetic nanoparticles-RCA immunoassay, is developed as a versatile fluorescence assay platform for highly sensitive proteins detection. PMID:22301574

  14. Micromotor-based lab-on-chip immunoassays

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

    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

  15. ULTRASENSITIVE IMMUNOASSAYS BASED ON SURFACE-ENHANCED RAMAN SCATTERING BY IMMUNOGOLD LABELS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter describes recent advances in the use of surface-enhanced Raman Scattering (SERS) as a readout tool for chip-scale, sandwich-based immunoassays. It reviews progress made in developing SERS-based immunoassays for a wide range of biolytes, including proteins, viruses and bacteria. The st...

  16. DEVELOPMENT OF A CLASS-SELECTIVE ENZYME IMMUNOASSAY FOR URINARY PHENOLIC GLUCURONIDES. (R825433)

    EPA Science Inventory

    Class-selective immunoassays for the measurement of glucuronides in human urine can aid evaluation of human exposure to complex mixtures of xenobiotics. Therefore, an enzyme immunoassay (EIA) for the group-selective detection of phenolic Microfluidic heavy metal immunoassay based on absorbance measurement.

    PubMed

    Date, Yasumoto; Terakado, Shingo; Sasaki, Kazuhiro; Aota, Arata; Matsumoto, Norio; Shiku, Hitoshi; Ino, Kosuke; Watanabe, Yoshitomo; Matsue, Tomokazu; Ohmura, Naoya

    2012-03-15

    A simple and rapid flow-based multioperation immunoassay for heavy metals using a microfluidic device was developed. The antigen-immobilized microparticles in a sub-channel were introduced as the solid phase into a main channel structures through a channel flow mechanism and packed into a detection area enclosed by dam-like structures in the microfluidic device. A mixture of a heavy metal and a gold nanoparticle-labeled antibody was made to flow toward the corresponding metal through the main channel and make brief contact with the solid phase. A small portion of the free antibody was captured and accumulated on the packed solid phase. The measured absorbance of the gold label was proportional to the free antibody portion and, thus, to the metal concentration. Each of the monoclonal antibodies specific for cadmium-EDTA, chromium-EDTA, or lead-DTPA was applied to the single-channel microfluidic device. Under optimized conditions of flow rate, volume, and antibody concentration, the theoretical (antibody K(d)-limited) detection levels of the three heavy metal species were achieved within only 7 min. The dynamic range for cadmium, chromium, and lead was 0.57-60.06 ppb, 0.03-0.97 ppb, and 0.04-5.28 ppb, respectively. An integrated microchannel device for simultaneous multiflow was also successfully developed and evaluated. The multiplex cadmium immunoassay of four samples was completed within 8 min for a dynamic range of 0.42-37.48 ppb. Present microfluidic heavy metal immunoassays satisfied the Japanese environmental standard for cadmium, chromium and, lead, which provided in the soil contamination countermeasures act. PMID:22244671

  17. Micromotor-based lab-on-chip immunoassays.

    PubMed

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

    2013-02-21

    Here we describe the first example of using self-propelled antibody-functionalized synthetic catalytic microengines for capturing and transporting target proteins between the different reservoirs of a lab-on-a-chip (LOC) device. A new catalytic polymer/Ni/Pt microtube engine, containing carboxy moieties on its mixed poly(3,4-ethylenedioxythiophene) (PEDOT)/COOH-PEDOT polymeric outermost layer, is further functionalized with the antibody receptor to selectively recognize and capture the target protein. The new motor-based microchip immunoassay operations are carried out without any bulk fluid flow, replacing the common washing steps in antibody-based protein bioassays with the active transport of the captured protein throughout the different reservoirs, where each step of the immunoassay takes place. A first microchip format involving an 'on-the-fly' double-antibody sandwich assay (DASA) is used for demonstrating the selective capture of the target protein, in the presence of excess of non-target proteins. A secondary antibody tagged with a polymeric-sphere tracer allows the direct visualization of the binding events. In a second approach the immuno-nanomotor captures and transports the microsphere-tagged antigen through a microchannel network. An anti-protein-A modified microengine is finally used to demonstrate the selective capture, transport and convenient label-free optical detection of a Staphylococcus aureus target bacteria (containing proteinA in its cell wall) in the presence of a large excess of non-target (Saccharomyces cerevisiae) cells. The resulting nanomotor-based microchip immunoassay offers considerable potential for diverse applications in clinical diagnostics, environmental and security monitoring fields. PMID:23123833

  18. Fast and Sensitive Detection of Enteropathogenic Yersinia by Immunoassays

    PubMed Central

    Laporte, Jérôme; Savin, Cyril; Lamourette, Patricia; Devilliers, Karine; Volland, Hervé; Carniel, Elisabeth; Créminon, Christophe

    2014-01-01

    Yersinia enterocolitica and Yersinia pseudotuberculosis, the two Yersinia species that are enteropathogenic for humans, are distributed worldwide and frequently cause diarrhea in inhabitants of temperate and cold countries. Y. enterocolitica is a major cause of foodborne disease resulting from consumption of contaminated pork meat and is further associated with substantial economic cost. However, investigation of enteropathogenic Yersinia species is infrequently performed routinely in clinical laboratories because of their specific growth characteristics, which make difficult their isolation from stool samples. Moreover, current isolation procedures are time-consuming and expensive, thus leading to underestimates of the incidence of enteric yersiniosis, inappropriate prescriptions of antibiotic treatments, and unnecessary appendectomies. The main objective of the study was to develop fast, sensitive, specific, and easy-to-use immunoassays, useful for both human and veterinary diagnosis. Monoclonal antibodies (MAbs) directed against Y. enterocolitica bioserotypes 2/O:9 and 4/O:3 and Y. pseudotuberculosis serotypes I and III were produced. Pairs of MAbs were selected by testing their specificity and affinity for enteropathogenic Yersinia and other commonly found enterobacteria. Pairs of MAbs were selected to develop highly sensitive enzyme immunoassays (EIAs) and lateral flow immunoassays (LFIs or dipsticks) convenient for the purpose of rapid diagnosis. The limit of detection of the EIAs ranged from 3.2 × 103 CFU/ml to 8.8 × 104 CFU/ml for pathogenic serotypes I and III of Y. pseudotuberculosis and pathogenic bioserotypes 2/O:9 and 4/O:3 of Y. enterocolitica and for the LFIs ranged from 105 CFU/ml to 106 CFU/ml. A similar limit of detection was observed for artificially contaminated human feces. PMID:25355759

  19. Gamete donation: ethical implications for donors.

    PubMed

    Shenfield, Francoise

    1999-01-01

    The interests of gamete donors have only recently been recognized in assisted reproduction; traditionally, the interests of the patients (typically a couple) and the prospective child are paramount. However, assisted reproduction would not be possible without donors, and the simple utilitarian view would be to place their interests first to maximize the availability of the practice. There are several ethical issues on both sides of the donor--recipient equation, some of which are mutual and others are in conflict. For example, the word 'donation' implies there is no payment. Informed consent for donation is essential if the autonomy of the donor is to be respected, and includes information about the results of screening. This is a sensitive issue, especially when pathology is found in a donor who is not being screened for his or her own immediate benefit. Counselling may result in donors refusing to take part, but may also lead to selection by the person recruiting the donors, sometimes as a consequence of examining the motivation of the donor. In this case, the main problem is the ethical basis of the selection process. Other aspects of gamete donation may lead to a conflict of interests between the donor, the recipients and even the prospective child, particularly in terms of anonymity and the information that is made available about the specific circumstances of donation. Implications and support counselling are essential tools in achieving an acceptable balance for all parties involved. PMID:11844334

  1. Supportive care in alternative donor transplantation.

    PubMed

    Fu, Shuang; Majhail, Navneet S

    2016-04-01

    Alternative donor hematopoietic cell transplantation (HCT) using umbilical cord blood, haploidentical or mismatched unrelated donors is a viable option for patients without human leukocyte antigen (HLA)-identical sibling or matched unrelated donors. The same principles of supportive care as conventional graft sources apply to alternative donor HCT recipients. However, there are some unique supportive care issues related to post-transplant complications, engraftment, graft-versus-host disease, immune reconstitution, and infections that are unique to each of the three alternative graft sources, both in the early and late post-transplant periods. This review discusses the supportive care issues relevant to this population and their management. PMID:27000738

  2. Alternative Donor Transplantation for Acute Myeloid Leukemia

    PubMed Central

    Bejanyan, Nelli; Haddad, Housam; Brunstein, Claudio

    2015-01-01

    Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative therapy for adult patients with acute myeloid leukemia (AML), but its use for consolidation therapy after first remission with induction chemotherapy used to be limited to younger patients and those with suitable donors. The median age of AML diagnosis is in the late 60s. With the introduction of reduced-intensity conditioning (RIC), many older adults are now eligible to receive allo-HCT, including those who are medically less fit to receive myeloablative conditioning. Furthermore, AML patients commonly have no human leukocyte antigen (HLA)-identical or medically suitable sibling donor available to proceed with allo-HCT. Technical advances in donor matching, suppression of alloreactivity, and supportive care have made it possible to use alternative donors, such as unrelated umbilical cord blood (UCB) and partially HLA-matched related (haploidentical) donors. Outcomes after alternative donor allo-HCT are now approaching the outcomes observed for conventional allo-HCT with matched related and unrelated donors. Thus, with both UCB and haploidentical donors available, lack of donor should rarely be a limiting factor in offering an allo-HCT to adults with AML. PMID:26239557

  3. Shallow donors in GaN.

    SciTech Connect

    Lee, S. K.; Koleske, Daniel David; Moore, W. J.; Freitas, J. A., Jr.; Shanabrook, B. V.; Braga, G. C. B.; Han, J. Y.; Park, S. S.

    2004-06-01

    High-resolution, variable temperature PL experiments were performed in the spectral region associated with recombination processes involving the ground and excited states of the neutral donor bound excitons. High-resolution infrared measurements in combination with high-sensitive SIMS unambiguously identified Si and O shallow donors and yield their ground state binding energies. These binding energies are in excellent agreement with values obtained by the analysis of the two-electron-satellite PL spectra considering the participation of ground and excited state donor bound excitons. This work clarifies conflicting aspects existing in donor identification and the binding energies of the impurities and excitons.

  4. Demonstration of four immunoassay formats using the array biosensor

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  5. Rapid enzyme immunoassay for measurement of bovine progesterone.

    PubMed

    Claycomb, R W; Delwiche, M J; Munro, C J; BonDurant, R H

    1998-11-15

    Reproductive management is a primary financial concern of the dairy industry with missed estrus detection one of the major causes of lost income. A rapid enzyme immunoassay (EIA) was developed for on-line measurement of progesterone in bovine milk with a biosensor for detection of estrus. The EIA was developed using covalent binding microtiter wells, monoclonal antibody, horseradish peroxidase, and 3,3',5,5'-tetramethylbenzidine (TMB). The EIA took 8 min and had a dynamic response for progesterone in buffer and milk between 0.2 and 20 ng/ml. PMID:9871971

  6. Magnetic particle detection by frequency mixing for immunoassay applications

    NASA Astrophysics Data System (ADS)

    Krause, Hans-Joachim; Wolters, Norbert; Zhang, Yi; Offenhäusser, Andreas; Miethe, Peter; Meyer, Martin H. F.; Hartmann, Markus; Keusgen, Michael

    2007-04-01

    For magnetic immunoassay applications, a novel magnetic reader for quantification of magnetic particle concentrations has been developed. Upon magnetic excitation at two distinct frequencies incident on the sample, the response signal generated at a sum frequency is detected. The low-frequency field component periodically drives the magnetic particles into saturation, which is probed by the high-frequency field. The appearance of frequency mixing lines is highly specific to the nonlinearity of the superparamagnetic particles' magnetization. The optimization of field coils, differential pickup coil, preamplifier, demodulators and filters are discussed. The output signal is linear for four orders of magnitude in iron concentration.

  7. Chemiluminescence enzyme immunoassay using ProteinA-bacterial magnetite complex

    NASA Astrophysics Data System (ADS)

    Matsunaga, Tadashi; Sato, Rika; Kamiya, Shinji; Tanaka, Tsuyosi; Takeyama, Haruko

    1999-04-01

    Bacterial magnetic particles (BMPs) which have ProteinA expressed on their surface were constructed using magA which is a key gene in BMP biosynthesis in the magnetic bacterium Magnetospirillum sp. AMB-1. Homogenous chemiluminescence enzyme immunoassay using antibody bound ProteinA-BMP complexes was developed for detection of human IgG. A good correlation between the luminescence yield and the concentration of human IgG was obtained in the range of 1-10 3 ng/ml.

  8. Pholcodine interference in the immunoassay for opiates in urine.

    PubMed

    Svenneby, G; Wedege, E; Karlsen, R L

    1983-01-01

    The excretion in urine after single oral therapeutic doses of morphine derivatives was analysed with radioimmunoassay (RIA) and homogeneous enzyme immunoassay (EMIT) for opiates. In contrast to the rapid excretion of ethylmorphine and codeine, pholcodine showed positive results for opiates 2-6 weeks after intake when the urines were analysed with the RIA-method. When analysed with the EMIT-method, positive results were obtained for pholcodine for approximately 10 days. As pholcodine is a common component in cough mixtures, its prolonged excretion could represent a hazard in interpreting the results from drug analyses of urines. PMID:6347841

  9. 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....

  10. Immunoassay Methods and their Applications in Pharmaceutical Analysis: Basic Methodology and Recent Advances

    PubMed Central

    Darwish, Ibrahim A.

    2006-01-01

    Immunoassays are bioanalytical methods in which the quantitation of the analyte depends on the reaction of an antigen (analyte) and an antibody. Immunoassays have been widely used in many important areas of pharmaceutical analysis such as diagnosis of diseases, therapeutic drug monitoring, clinical pharmacokinetic and bioequivalence studies in drug discovery and pharmaceutical industries. The importance and widespread of immunoassay methods in pharmaceutical analysis are attributed to their inherent specificity, high-throughput, and high sensitivity for the analysis of wide range of analytes in biological samples. Recently, marked improvements were achieved in the field of immunoassay development for the purposes of pharmaceutical analysis. These improvements involved the preparation of the unique immunoanalytical reagents, analysis of new categories of compounds, methodology, and instrumentation. The basic methodologies and recent advances in immunoassay methods applied in different fields of pharmaceutical analysis have been reviewed. PMID:23674985

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

    NASA Technical Reports Server (NTRS)

    Ponce, Adrian

    2003-01-01

    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

  12. Enhanced Fluorescent Immunoassays on Silver Fractal-like Structures

    PubMed Central

    Shtoyko, Tanya; Matveeva, Evgenia G.; Chang, I-Fen; Gryczynski, Zygmunt; Goldys, Ewa; Gryczynski, Ignacy

    2009-01-01

    Using the effect of the fluorescence enhancement in close proximity to metal nanostructures, we have been able to demonstrate ultrasensitive immunoassays suitable for the detection of biomarkers. Silver fractal-like structures have been grown by electrochemical reduction of silver on the surface of glass slides. A model immunoassay was performed on the slide surface with rabbit IgG (antigen) non-covalently immobilized on the slide, and Rhodamine Red-X labeled anti-rabbit IgG conjugate subsequently bound to the immobilized antigen. The fluorescence signal was measured from the glass-fractals surface using a confocal microscope, and the images were compared to the images from the same surface not coated with fractals. Our results showed significant enhancement (more than 100-fold) of the signal detected on fractals compared to bare glass. We thus demonstrate that such fractal-like structures can assist in improving the signals from assays used in medical diagnostics, especially those for analytes with molecular weight under 100 kD. PMID:18288816

  13. Enhanced fluorescent immunoassays on silver fractal-like structures.

    PubMed

    Shtoyko, Tanya; Matveeva, Evgenia G; Chang, I-Fen; Gryczynski, Zygmunt; Goldys, Ewa; Gryczynski, Ignacy

    2008-03-15

    Using the effect of the fluorescence enhancement in close proximity to metal nanostructures, we have been able to demonstrate ultrasensitive immunoassays suitable for the detection of biomarkers. Silver fractal-like structures have been grown by electrochemical reduction of silver on the surface of glass slides. A model immunoassay was performed on the slide surface with rabbit IgG (antigen) noncovalently immobilized on the slide, and rhodamine red-X-labeled antirabbit IgG conjugate was subsequently bound to the immobilized antigen. The fluorescence signal was measured from the glass-fractal's surface using a confocal microscope, and the images were compared to the images from the same surface not coated with fractals. Our results showed significant enhancement (more than 100-fold) of the signal detected on fractals compared to bare glass. We thus demonstrate that such fractal-like structures can assist in improving the signals from assays used in medical diagnostics, especially those for analytes with molecular weight under 100 kDa. PMID:18288816

  14. Aequorin fusion proteins as bioluminescent tracers for competitive immunoassays

    NASA Astrophysics Data System (ADS)

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

    2004-06-01

    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.

  15. Quantitative immunoassay of human deoxycytidine kinase in malignant cells.

    PubMed

    Kawasaki, H; Carrera, C J; Carson, D A

    1992-11-15

    Deoxycytidine kinase (dCK) is necessary for the activity of several nucleosides used for the chemotherapy of cancer and AIDS. However, the measurement of dCK catalytic activity in crude cell extracts may be imprecise, due to the presence of phosphatases and nucleotidases that degrade the enzyme products. We describe a simple immunoassay for dCK that can measure accurately as little as 5 ng enzyme protein in crude tissue extracts. The assay enabled us to show (i) that mutant cells deficient in dCK activity lack immunoreactive dCK protein, (ii) that dCK catalytic activity and immunoreactivity correlate closely in human tumors, and (iii) that immunoreactive dCK is particularly high in lymphocytes and lymphoid malignancies, although certain solid tumors may also contain the enzyme. The immunoassay of dCK could prove useful in the selection and monitoring of patients who are being treated with nucleosides that are activated by this enzyme. PMID:1489095

  16. The development of immunoassays for detection of chemical warfare agents

    SciTech Connect

    Lenz, D.E.

    1995-06-01

    With the advent of enzyme linked immunoabsorbant assays (ELISA) and monoclonal antibodies in the last two decades, there has been considerable effort devoted to the development of antibodies to detect and quantify low molecular weight toxic substances in environmental or biological fluids. Polyclonal antibodies against paraoxon (the toxic metabolite of parathion) were reported as capable of detecting paraoxon in body fluids at a level of 10{sup -9} M ({approximately}260 pg/mL) when used in a competitive inhibition enzyme immunoassay (CIEIA). Monoclonal antibodies developed against a structural analogue of the chemical warfare agent soman were capable of detecting soman in buffer solutions at a level of 10{sup -6} M ({approximately}180 ng/mL). In addition, these antibodies were highly specific for soman even in the presence of its major hydrolysis product. Subsequent studies with antisoman monoclonal antibodies reported an extension of the level of sensitivity to -80 ng/mL. Furthermore these antibodies did not cross react with other chemical warfare nerve agents such as sarin or tabun. In all cases, the time for a confirmatory test was two hours or less. Immunoassays for T-2 micotoxins have also been reported with a minimal detection range of 2 pg/assay to 50 ng/assay for the polyclonal and monoclonal T-2 antibodies respectively. These antibodies offer a sensitive, rapid and low cost approach to the diagnosis or detection of the presence of toxic chemical substances.

  17. Detection of the Antimicrobial Triclosan in Environmental Samples by Immunoassay.

    PubMed

    Ahn, Ki Chang; Ranganathan, Anupama; Bever, Candace S; Hwang, Sung Hee; Holland, Erika B; Morisseau, Kevin; Pessah, Isaac N; Hammock, Bruce D; Gee, Shirley J

    2016-04-01

    A sensitive, competitive enzyme-linked immunosorbent assay (ELISA) for the detection of the antimicrobial triclosan (TCS; 2,4,4'-trichloro-2'-hydroxydiphenyl ether) was developed. Novel immunizing haptens were synthesized by derivatizing at the 4-Cl position of the TCS molecule. Compounds derived from substitutions at 4'-Cl and that replaced the 2'-OH with a Cl atom were designed as unique coating antigen haptens. Polyclonal rabbit antisera were screened against the coating antigen library to identify combinations of immunoreagents resulting in the most sensitive assays. The most sensitive assay identified was one utilizing antiserum no. 1155 and a heterologous competitive hapten, where the 2'-OH group was substituted with a Cl atom. An IC50 value and the detection range for TCS in assay buffer were 1.19 and 0.21-6.71 μg/L, respectively. The assay was selective for TCS, providing low cross-reactivity (<5%) to the major metabolites of TCS and to brominated diphenyl ether-47. A second assay utilizing a competitive hapten containing Br instead of Cl substitutions was broadly selective for both brominated and chlorinated diphenylethers. Using the most sensitive assay combination, we measured TCS concentrations in water samples following dilution. Biosolid samples were analyzed following the dilution of a simple solvent extract. The immunoassay results were similar to those determined by LC-MS/MS. This immunoassay can be used as a rapid and convenient tool to screen for human and environmental exposure. PMID:26937944

  18. Chemiluminescent immunoassay of thyroxine enhanced by microchip electrophoresis

    PubMed Central

    Huang, Yong; Zhao, Shulin; Shi, Ming; Liu, Yi-Ming

    2010-01-01

    A homogenous chemiluminescent immunoassay of thyroxine (T4) enhanced by microchip electrophoresis separation has been developed. The method deployed the competitive immunoreaction of T4 and horseradish peroxidase (HRP)-labeled T4 (HRP–T4) with anti-T4 mouse monoclonal antibody (Ab). HRP–T4 and the HRP–T4–Ab complex were separated and quantified by using microchip electrophoresis (MCE) with chemiluminescence (CL) detection. Highly sensitive CL detection was achieved by means of HPR-catalyzed luminol-H2O2 reaction. Due to the effective MCE separation, the CL analytical signal was less prone to sample matrix interference. Under the selected assay conditions, the MCE separation was accomplished within 60 sec. The linear range for T4 were 5-250 nM with a detection limit of 2.2 nM (S/N = 3). The present method was successfully applied for the quantification of T4 in human serum samples. It was demonstrated that the present MCE-CL enhanced competitive immunoassay was quick, sensitive, and highly selective. It may serve as a tool for clinical analysis of T4 to assist diagnosis of thyroid gland functions. PMID:19961826

  19. Magnetic immunoassay for detection of staphylococcal toxins in complex media.

    PubMed

    Orlov, Alexey V; Khodakova, Julia A; Nikitin, Maxim P; Shepelyakovskaya, Anna O; Brovko, Fedor A; Laman, Alexander G; Grishin, Evgeny V; Nikitin, Petr I

    2013-01-15

    Method of highly sensitive registration of magnetic nanoparticles by their nonlinear magnetization is used in a novel sandwich-type immunoassay for detection of staphylococcal toxins in complex media of virtually any volume, with increasing sensitivity at higher sample volume. The signal is read out from the entire volume of a nontransparent 3D fiber structure employed as a solid phase, which provides large reaction surface, quick reagent mixing, as well as antigen immunofiltration directly in the course of the assay. The method has demonstrated near-linear dose-response curves within a wide range of ~3 decades, while detection of staphylococcal enterotoxin A (SEA) and toxic shock syndrome toxin (TSST) in neat milk without sample preparation. The limits of detection (LOD) as low as 4 and 10 pg/mL for TSST and SEA, respectively, were obtained in 2-h format using 30-mL samples. The second, 25-min format, showed the LOD of 0.1 and 0.3 ng/mL for the same toxins in a 150 μL sample. The developed immunoassay can be applied in food safety control, in vitro diagnostics, and veterinary for a variety of research from express tests in the field to highly sensitive laboratory tests. PMID:23244173

  20. Sensitive chemiluminescent immunoassay of triclopyr by digital image analysis.

    PubMed

    Díaz, Aurora N; Sánchez, Francisco G; Baro, Enrique N; Díaz, Ana F G; Aguilar, Alfonso; Algarra, Manuel

    2012-08-15

    An image based detection of chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA) for the quantification of triclopyr has been developed. The immunoassay was an indirect competitive immunoassay with an anti-rabbit secondary antibody conjugated to horseradish peroxidase (HRP). Chemiluminescence was produced by the luminol/H(2)O(2)/HRP reaction, detected by a monochrome video CCD camera and digitized with an Imagraph IC-PCI frame grabber using a custom program developed in C(++) (Microsoft Visual C(++) 6.0). Two main improvements are reported in the data processing software: the implementation of a circular mesh covering the perimeter of each well, eliminating diffuse light from the neighboring wells, and the use of volume (the integration of light intensity of all pixels that define a well) as an analytical signal instead of CL intensity or area (as usual in commercial plate readers) to improve precision for normalization of the total light output. The standard curve was produced for 0.01-10 ng/L triclopyr. The limit of detection was 0.8 ng/L and the variation coefficient was 3.07% (n=10, P=0.05). PMID:22841045

  1. A Method for Designing Instrument-Free Quantitative Immunoassays.

    PubMed

    Lathwal, Shefali; Sikes, Hadley D

    2016-03-15

    Colorimetric readouts are widely used in point-of-care diagnostic immunoassays to indicate either the presence or the absence of an analyte. For a variety of reasons, it is more difficult to quantify rather than simply detect an analyte using a colorimetric test. We report a method for designing, with minimal iteration, a quantitative immunoassay that can be interpreted objectively by a simple count of number of spots visible to the unaided eye. We combined a method called polymerization-based amplification (PBA) with a series of microscale features containing a decreasing surface density of capture molecules, and the central focus of the study is understanding how the choice of surface densities impacts performance. Using a model pair of antibodies, we have shown that our design approach does not depend on measurement of equilibrium and kinetic binding parameters and can provide a dynamic working range of 3 orders of magnitude (70 pM to 70 nM) for visual quantification. PMID:26878154

  2. Development of surface-plasmon-resonance-based immunoassay for cephalexin

    NASA Astrophysics Data System (ADS)

    Dillon, Paul P.; Daly, Stephen J.; Browne, Johnathan; Manning, Bernadette M.; O'Kennedy, Richard; van Amerongen, Aart

    2003-03-01

    The public concern surrounding antibiotic contamination in food and food products has made it imperative to develop analytical methods for their detection. Polyclonal antibodies and protein-hapten conjugates to cephalexin were used in the development of a surface plasmon resonance (SPR)-based inhibition immunoassay to cephalexin. A conjugate consisting of cephalexin-bovine serum albumin (BSA) was immobilised on the dextran gel surface. Dissociation between the antibody and antigen was easily achieved with 10 mmol l-1 NaOH and was very reproducible. Standards of free hapten were prepared and premixed with antibody and, after a suitable incubation time, passed over the surface of the chip with the protein-hapten conjugate immobilised. The hapten in solution inhibited the binding of antibody to the surface resulting in higher response units of antibody bound at lower concentrations of free drug. Model inhibition immunoassays to cephalexin were developed in PBS and spiked milk samples. These assays had detection ranges between 4.88 to 2,500 ng ml-1 and 244 to 3,900 ng ml-1, respectively, with reproducible results.

  3. Use of cerebrospinal fluid enzyme immunoassay for diagnosis of neurosyphilis.

    PubMed

    Chan, Yung; Yeung, Kwok-Hung; Ho, Hing-Fung; Ho, King-Man; Tin-Keung Lam, Edman; Leung, Wai-Lin; Kam, Kai-Man

    2014-07-01

    Neurosyphilis is a difficult clinical stage of syphilis as there is no ideal method for diagnosis and workup requires lumbar puncture which may sometimes provide ambiguous results especially in HIV co-infected patients. Enzyme immunoassay is a widely used screening test for syphilis in serum, but its test performance was not well studied in cerebrospinal fluid. To examine the diagnostic performance of cerebrospinal fluid-enzyme immunoassay (CSF-EIA) in neurosyphilis, we conducted a prospective study for two years. All consecutive patients admitted for workup of neurosyphilis under the Social Hygiene Service, in Hong Kong, were included. Laboratory tests on CSF included several serological tests, CSF cell count, and protein. Forty-five patients were prospectively recruited, of which 29 people were living with HIV / AIDS. Using diagnostic case definition standard stipulated in the IUSTI 2008 guidelines, 17 patients satisfied the diagnosis of neurosyphilis. The CSF-EIA test provided 100% in both sensitivity and negative predictive value; its specificity was 46.4% (13/28, 95% CI 31.8-61%). Specificity improved to 80.8% (95% CI: 68.4-93.2%) with optical density cut-off value at 1.4 for cases with CSF red cell counts <600/mm(3) This is the first study on use of CSF-EIA in neurosyphilis. CSF-EIA showed high sensitivity and high negative predictive value in the study population and the presence of CSF red cells < 600/mm(3)might not affect its accuracy. PMID:24334293

  4. Bioluminescent detection probe for tick-borne encephalitis virus immunoassay.

    PubMed

    Burakova, Ludmila P; Kudryavtsev, Alexander N; Stepanyuk, Galina A; Baykov, Ivan K; Morozova, Vera V; Tikunova, Nina V; Dubova, Maria A; Lyapustin, Victor N; Yakimenko, Valeri V; Frank, Ludmila A

    2015-07-01

    To facilitate the detection of the tick-borne encephalitis virus (TBEV), the causative agent of one of the most severe human neuroinfections, we have developed an immunoassay based on bioluminescent hybrid protein 14D5a-Rm7 as a detection probe. The protein containing Renilla luciferase as a reporter and a single-chain variable fragment (scFv) of murine immunoglobulin to TBEV as a recognition element was constructed, produced by bacterial expression, purified, and tested. Both domains were shown to reveal their specific biological properties-affinity to the target antigen and bioluminescent activity. Hybrid protein was applied as a label for solid-phase immunoassay of the antigens, associated with the tick-borne encephalitis virus (native glycoprotein E or extracts of the infected strain of lab ticks). The assay demonstrates high sensitivity (0.056 ng of glycoprotein E; 10(4)-10(5) virus particles or 0.1 pg virions) and simplicity and is competitive with conventional methods for detection of TBEV. PMID:25925861

  5. Development of an Heterologous Immunoassay for Ciprofloxacin Residue in Milk

    NASA Astrophysics Data System (ADS)

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

    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.

  6. Multiplex Detection of Plant Pathogens Using a Microsphere Immunoassay Technology

    PubMed Central

    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

    Plant pathogens are a serious problem for seed export, plant disease control and plant quarantine. Rapid and accurate screening tests are urgently required to protect and prevent plant diseases spreading worldwide. A novel multiplex detection method was developed based on microsphere immunoassays to simultaneously detect four important plant pathogens: a fruit blotch bacterium Acidovorax avenae subsp. citrulli (Aac), chilli vein-banding mottle virus (CVbMV, potyvirus), watermelon silver mottle virus (WSMoV, tospovirus serogroup IV) and melon yellow spot virus (MYSV, tospovirus). An antibody for each plant pathogen was linked on a fluorescence-coded magnetic microsphere set which was used to capture corresponding pathogen. The presence of pathogens was detected by R-phycoerythrin (RPE)-labeled antibodies specific to the pathogens. The assay conditions were optimized by identifying appropriate antibody pairs, blocking buffer, concentration of RPE-labeled antibodies and assay time. Once conditions were optimized, the assay was able to detect all four plant pathogens precisely and accurately with substantially higher sensitivity than enzyme-linked immunosorbent assay (ELISA) when spiked in buffer and in healthy watermelon leaf extract. The assay time of the microsphere immunoassay (1 hour) was much shorter than that of ELISA (4 hours). This system was also shown to be capable of detecting the pathogens in naturally infected plant samples and is a major advancement in plant pathogen detection. PMID:23638044

  7. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS... deferral. (a) You, an establishment that collects human blood or blood components, must defer donors... donations of human blood and blood components, except: (1) You are not required to defer a donor who...

  8. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Donor deferral. 610.41 Section 610.41 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS GENERAL BIOLOGICAL PRODUCTS STANDARDS Testing Requirements for Communicable Disease Agents § 610.41 Donor deferral. (a) You, an establishment that...

  9. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS... deferral. (a) You, an establishment that collects human blood or blood components, must defer donors... donations of human blood and blood components, except: (1) You are not required to defer a donor who...

  10. 21 CFR 610.41 - Donor deferral.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) BIOLOGICS... deferral. (a) You, an establishment that collects human blood or blood components, must defer donors... donations of human blood and blood components, except: (1) You are not required to defer a donor who...

  11. The Experience of Living Kidney Donors

    ERIC Educational Resources Information Center

    Brown, Judith Belle; Karley, Mary Lou; Boudville, Neil; Bullas, Ruth; Garg, Amit X.; Muirhead, Norman

    2008-01-01

    This article describes the experiences, feelings, and ideas of living kidney donors. Using a phenomenological, qualitative research approach, the authors interviewed 12 purposefully selected living kidney donors (eight men and four women), who were between four and 29 years since donation. Interviews were audiotaped, and transcribed verbatim, and…

  12. Application of elderly donor for liver transplantation

    PubMed Central

    Li, Jiang; Wang, Kai

    2015-01-01

    Recently, much more attention has been paid on application of elderly donor due to the shortage of organs. Although liver quality of elderly donors may be sub-optimal comparing with that from younger donors, primary non-function of a liver graft is a rare event. On the other hand, long-term graft and recipient survival for usage of elderly grafts has become a major concern and focus of research. Many transplant centers have changed the upper limit of donor age from previous 50 to 70 or even 75-year-old and achieved good graft function. Although some scholars believed that liver transplant using elderly grafts was associated with high probability of delayed liver function recovery, graft loss and hepatitis C recurrence, reports from several transplant centers document that long-term survival of grafts and recipients may be significantly improved through certain screening of donors and recipients before transplant. In conclusion, it is very important and relatively safe to use grafts from elderly donors to expand the donor pool. However, elderly donors and corresponding recipients must be carefully selected before transplant. The long-term effect of advanced age on grafts and recipients need to be evaluated through a comprehensive and long-term in-depth observation. PMID:26379822

  13. Negotiating boundaries: Accessing donor gametes in India

    PubMed Central

    Widge, A.; Cleland, J.

    2011-01-01

    Background: This paper documents how couples and providers access donor materials for conception in the Indian context and perceptions about using them. The objective is to facilitate understanding of critical issues and relevant concerns. Methods: A postal survey was conducted with a sample of 6000 gynaecologists and in-depth interviews were conducted with 39 gynaecologists in four cities. Results: Donor gametes are relatively more acceptable than a few years ago, especially if confidentiality can be maintained, though lack of availability of donor materials is sometimes an impediment to infertility treatment. Donor sperms are usually accessed from in-house or commercial sperm banks, pathology laboratories, IVF centres, professional donors, relatives or friends. There is scepticism about screening procedures of sperm banks. Donor eggs are usually accessed from voluntary donors, friends, relatives, egg sharing programmes, donation from other patients, advertising and commercial donors. There are several concerns regarding informed consent for using donated gametes, using relatives and friends gametes, the unregulated use of gametes and embryos, record keeping and documentation, unethical and corrupt practices and commercialisation. Conclusion: These issues need to be addressed by patients, providers and regulatory authorities by providing information, counselling, ensuring informed consent, addressing exploitation and commercialisation, ensuring monitoring, proper documentation and transparency. PMID:24753849

  14. Studies of donors who transmit posttransfusion hepatitis.

    PubMed

    Tabor, E; Hoofnagle, J H; Smallwood, L A; Drucker, J A; Pineda-Tamondong, G C; Ni, L Y; Greenwalt, T J; Barker, L F; Gerety, R J

    1979-01-01

    Sera and questionnaires were evaluated retrospectively from 128 volunteer blood donors whose blood had been implicated in cases of clinically recognized post-transfusion hepatitis in recipients of one- or two-unit blood transfusion between 1971 and 1977. Serologic markers of hepatitis B virus (HBV) infection were found in 23 percent, compared to 9.7 percent of 3,230 prospective blood donors. The prevalence of antibody to hepatitis A virus was similar among implicated donors (44%), prospective donors (58%), and among those implicated donors with (41%) and without (44%) HBV markers. Among implicated donors, none had a history at the time of donation of having had clinically recognizable hepatitis, 93 percent had no history of prior blood transfusion, and 80 percent had normal hepatic enzymes. Data from this study confirm that non-A, non-B hepatitis has been a common form of posttransfusion hepatitis in recent years, since 77 percent of these implicated donors had no HBV serologic markers. In addition, these donors could not be distinguished by age, race, sex, history of clinical hepatitis or of prior blood transfusion, or in most cases by hepatic enzyme levels. PMID:230620

  15. Payment for donor kidneys: pros and cons.

    PubMed

    Friedman, E A; Friedman, A L

    2006-03-01

    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

  16. The value of living donor liver transplantation.

    PubMed

    Yang, Xiaoli; Gong, Junhua; Gong, JianPing

    2012-12-31

    Living donor liver transplantation (LDLT) is a very successful procedure that develops liver resources in case of worldwide shortages. As the technology has developed so much in the past 2 decades, LDLT has the same good prognosis as DDLT. However, LDLT still has lots of ethical & technical problems. It causes great psychiatric, physical and psychosocial harm to donors. Also, it has some negative effects on society by providing a platform for organ trade. Therefore, there is much controversy about the social value of LDLT. After review of recent papers, we find much progress can be made in inspiring the public to become organ donors and creating donation model new to improve the consent rate for solid organ donation from deceased donors. That is the key strategy for increasing the liver supply. With this serious shortage of organs, liver donor transplantation still has its advantages, but we should not place all our hopes on LDLT to increase the liver supply. We all need to try our best to increase donor awareness and promote organ donor registration--when cadaver organs could meet the needs for liver transplantation, living donor liver transplants would not be necessary. PMID:23274332

  17. The Experience of Living Kidney Donors

    ERIC Educational Resources Information Center

    Brown, Judith Belle; Karley, Mary Lou; Boudville, Neil; Bullas, Ruth; Garg, Amit X.; Muirhead, Norman

    2008-01-01

    This article describes the experiences, feelings, and ideas of living kidney donors. Using a phenomenological, qualitative research approach, the authors interviewed 12 purposefully selected living kidney donors (eight men and four women), who were between four and 29 years since donation. Interviews were audiotaped, and transcribed verbatim, and

  18. Kinetics of thermal donor generation in silicon

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

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

    PubMed

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

    2011-07-01

    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 < 6%) with the microtiter plate, confirming the great potential of this analytical platform in the field of immunodiagnosis. PMID:21547429

  20. On-chip native gel electrophoresis-based immunoassays for tetanus antibody and toxin.

    PubMed

    Herr, Amy E; Throckmorton, Daniel J; Davenport, Andrew A; Singh, Anup K

    2005-01-15

    By integrating photopolymerized cross-linked polyacrylamide gels within a microfluidic device, we have developed a microanalytical platform for performing electrophoresis-based immunoassays. The microfluidic immunoassays are performed by gel electrophoretic separation and quantitation of bound and unbound antibody or antigen. To retain biological activity of proteins and maintain intact immune complexes, nondenaturing polyacrylamide gel electrophoresis conditions were investigated. Both direct (noncompetitive) and competitive immunoassay formats are demonstrated in microchips. A direct immunoassay was developed for detection of tetanus antibodies in buffer as well as diluted serum samples. After an off-chip incubation step, the immunoassay was completed in less than 3 min and the sigmoidal dose-response curve spanned an antibody concentration range from 0.17 to 260 nM. The minimum detectable antibody concentration was 0.68 nM. A competitive immunoassay was also developed for tetanus toxin C-fragment by allowing unlabeled and fluorescently labeled tetanus toxin C-fragment compete to bind to a limited fixed concentration of tetanus antibody. The immunoassay technique described in this work shows promise as a component of an integrated microfluidic device amenable to automation and relevant to development of clinical diagnostic devices. PMID:15649057

  1. Nanobody medicated immunoassay for ultrasensitive detection of cancer biomarker alpha-fetoprotein.

    PubMed

    Chen, Jing; He, Qing-hua; Xu, Yang; Fu, Jin-heng; Li, Yan-ping; Tu, Zhui; Wang, Dan; Shu, Mei; Qiu, Yu-lou; Yang, Hong-wei; Liu, Yuan-yuan

    2016-01-15

    Immunoassay for cancer biomarkers plays an important role in cancer prevention and early diagnosis. To the development of immunoassay, the quality and stability of applied antibody is one of the key points to obtain reliability and high sensitivity for immunoassay. The main purpose of this study was to develop a novel immunoassay for ultrasensitive detection of cancer biomarker alpha-fetoprotein (AFP) based on nanobody against AFP. Two nanobodies which bind to AFP were selected from a phage display nanobody library by biopanning strategy. The prepared nanobodies are clonable, thermally stable and applied in both sandwich enzyme linked immunoassay (ELISA) and immuno-PCR assay for ultrasensitive detection of AFP. The limit detection of sandwich ELISA setup with optimized nanobodies was 0.48ng mL(-1), and the half of saturation concentration (SC50) value was 6.68±0.56ng mL(-1). These nanobodies were also used to develop an immuno-PCR assay for ultrasensitive detection of AFP, its limit detection values was 0.005ng mL(-1), and the linear range was 0.01-10,000ng mL(-1). These established immunoassays based on nanobodies were highly specific to AFP and with negligible cross reactivity with other tested caner biomarkers. Furthermore, this novel concept of nanobodies mediated immunoassay may provide potential applications in a general method for the ultrasensitive detection of various cancer biomarkers. PMID:26592642

  2. Liver regeneration after living donor transplant

    PubMed Central

    Olthoff, Kim M.; Emond, Jean C.; Shearon, Tempie H.; Everson, Greg; Baker, Talia B.; Fisher, Robert A.; Freise, Chris E.; Gillespie, Brenda W.; Everhart, James E.

    2014-01-01

    Background & Aims Adult-to-adult living donors and recipients were studied to characterize patterns of liver growth and identify associated factors in a multicenter study. Methods 350 donors and 353 recipients in A2ALL (Adult to Adult Living Donor Liver Transplantation Cohort Study) transplanted between March 2003 and February 2010 were included. Potential predictors of 3-month liver volume included total and standard liver volumes (TLV, SLV), the model for end-stage liver disease (MELD) score (in recipients), remnant and graft size, remnant to donor and graft to recipient weight ratio (RDWR, GRWR), remnant/TLV, and graft/SLV. Results Among donors, 3-month absolute growth was 676±251g (mean± SD) and percent reconstitution was 80%±13%. Among recipients, GRWR was 1.3%±0.4% (8<0.8%). Graft weight was 60%±13% of SLV. Three-month absolute growth was 549±267g and percent reconstitution was 93%±18%. Predictors of greater 3-month liver volume included larger patient size (donors, recipients), larger graft volume (recipients), and larger TLV (donors). Donors with the smallest remnant/TLV ratios had larger than expected growth, but also had higher postoperative bilirubin and international normalized ratio at 7 and 30 days. In a combined donor-recipient analysis, donors had smaller 3-month liver volumes than recipients adjusted for patient size, remnant or graft volume, and TLV or SLV (p=0.004). Recipient graft failure in the first 90 days was predicted by poor graft function at day 7 (HR=4.50, p=0.001), but not by GRWR or graft fraction (p>0.90 for each). Conclusions Both donors and recipients had rapid yet incomplete restoration of tissue mass in the first 3 months, confirming previous reports. Recipients achieved a greater percentage of expected total volume. Patient size and recipient graft volume significantly influenced 3 month volumes. Importantly, donor liver volume is a critical predictor of the rate of regeneration, and donor remnant fraction impacts post-resection function. PMID:25065488

  3. Bright Solid-State Emission of Disilane-Bridged Donor-Acceptor-Donor and Acceptor-Donor-Acceptor Chromophores.

    PubMed

    Shimada, Masaki; Tsuchiya, Mizuho; Sakamoto, Ryota; Yamanoi, Yoshinori; Nishibori, Eiji; Sugimoto, Kunihisa; Nishihara, Hiroshi

    2016-02-01

    The development of disilane-bridged donor-acceptor-donor (D-Si-Si-A-Si-Si-D) and acceptor-donor-acceptor (A-Si-Si-D-Si-Si-A) compounds is described. Both types of compound showed strong emission (λem =ca. 500 and ca. 400 nm, respectively) in the solid state with high quantum yields (Φ: up to 0.85). Compound 4 exhibited aggregation-induced emission enhancement in solution. X-ray diffraction revealed that the crystal structures of 2, 4, and 12 had no intermolecular π-π interactions to suppress the nonradiative transition in the solid state. PMID:26822564

  4. Blood donors screening for malaria in non-endemic area in the Kingdom of Saudi Arabia: Is it necessary to introduce immunological testing?

    PubMed Central

    Elyamany, Ghaleb; Al Gharawi, Ali; Alrasheed, Mohammed; Alsuhaibani, Omar

    2016-01-01

    Introduction In Saudi Arabia, where malaria is not endemic, the incidence is very low. However, malaria transmission cases have been reported, mainly in Asir and Jazan provinces along the Southwestern border with Yemen. Imported cases also have been reported. The aims of this study were to determine the prevalence of malaria in blood donors in a tertiary care hospital in the central area of Saudi Arabia and to assess the effectiveness of malaria screening methods used by transfusion services in Prince Sultan Military Medical City. Methods This study was conducted on 180,000 people who donated blood during 2006–2015. All blood smears from blood donors were screened for malaria infection using Giemsa staining, low power and high power microscopic examinations, and using oil immersion lens. The data were analyzed and reported in descriptive statistics and prevalence. Results From the total of 180,000 blood donors who were screened for malaria, 156,000 (87%) and 23.400 (13%) were Saudi Arabia citizens and non-Saudi residents, respectively. The mean age of the blood donors was 32 (ranging from 18 to 65), 97% and 3% were male and female, respectively. Using our current method for malaria screening, the prevalence of malaria in the study population was zero. Conclusion The current methods of malaria screening in blood donors is not suitable for screening low-level parasiotemia. Adding the immunoassay and molecular screening methods is suggested. PMID:27054011

  5. Donor research in australia: challenges and promise.

    PubMed

    Masser, Barbara; Smith, Geoff; Williams, Lisa A

    2014-07-01

    Donors are the key to the core business of Blood Collection Agencies (BCAs). However, historically, they have not been a focus of research undertaken by these organizations. This model is now changing, with significant donor research groups established in a number of countries, including Australia. Donor research in the Australian Red Cross Blood Service (Blood Service) is concentrated in the Donor and Community Research (DCR) team. Cognizant of the complex and ever-changing landscape with regard to optimal donor management, the DCR team collaborates with academics located at universities around Australia to coordinate a broad program of research that addresses both short- and-long term challenges to the blood supply. This type of collaboration is not, however, without challenges. Two major collaborative programs of the Blood Service's research, focusing on i) the recruitment and retention of plasmapheresis donors and ii) the role of the emotion pride in donor motivation and return, are showcased to elucidate how the challenges of conducting collaborative BCA research can be met. In so doing, these and the other research programs described herein demonstrate how the Blood Service supports and contributes to research that not only revises operational procedures but also contributes to advances in basic science. PMID:25254025

  6. Donor Research in Australia: Challenges and Promise

    PubMed Central

    Masser, Barbara; Smith, Geoff; Williams, Lisa A.

    2014-01-01

    Summary Donors are the key to the core business of Blood Collection Agencies (BCAs). However, historically, they have not been a focus of research undertaken by these organizations. This model is now changing, with significant donor research groups established in a number of countries, including Australia. Donor research in the Australian Red Cross Blood Service (Blood Service) is concentrated in the Donor and Community Research (DCR) team. Cognizant of the complex and ever-changing landscape with regard to optimal donor management, the DCR team collaborates with academics located at universities around Australia to coordinate a broad program of research that addresses both short- and-long term challenges to the blood supply. This type of collaboration is not, however, without challenges. Two major collaborative programs of the Blood Service's research, focusing on i) the recruitment and retention of plasmapheresis donors and ii) the role of the emotion pride in donor motivation and return, are showcased to elucidate how the challenges of conducting collaborative BCA research can be met. In so doing, these and the other research programs described herein demonstrate how the Blood Service supports and contributes to research that not only revises operational procedures but also contributes to advances in basic science. PMID:25254025

  7. Multiplexed immunoassays for biomonitoring of exposure to agrochemicals using quantum dots as fluorescent reporters

    NASA Astrophysics Data System (ADS)

    Nichkova, Mikaela; Dosev, Dosi; Davies, Alexander E.; Gee, Shirley J.; Kennedy, Ian M.; Hammock, Bruce D.

    2007-02-01

    The application of quantum dots (QDs) as labels in immunoassay microarrays for the multiplex detection of 3- phenoxybenzoic acid (PBA) and atrazine-mercapturate (AM) has been demonstrated. PBA and AM are biomarkers of exposure to the pyrethroid insecticides and to the herbicide atrazine, respectively. Microarrays were fabricated by microcontact printing of the coating antigens in line patterns onto glass substrates. Competitive immunoassays were successfully performed using quantum dots (QD560 and QD620) as reporters. The multiplexed immunoassays were characterized by fluorescence microscopy and SEM. The application of QD fluorophores facilitates multiplex assays and therefore can contribute to enhanced throughput in biomonitoring.

  8. Integration of nanomaterials for colorimetric immunoassays with improved performance: a functional perspective.

    PubMed

    Zheng, Wenshu; Jiang, Xingyu

    2016-02-01

    The boom of nanotechnology has yielded exciting developments in designing new kinds of colorimetric immunoassays. These nanomaterial-associated immunoassays have shown great potential for clinical translation and a number of them have already been implemented for testing patient samples from the clinics. Different from most reviews where researchers typically focus on a specific type of nanomaterial or describe assays based on the types of materials, we classify these assays by the function of nanomaterials, focusing on reviewing the distinct phenomenon of nanomaterials and how these properties are utilized to overcome limitations faced by traditional colorimetric immunoassays. We also discuss the challenges and give our perspectives in this field. PMID:26820316

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

    PubMed Central

    Selahi, Fatemeh; Hosseini, Mohammad Hossein; Mansourian, Maryam; Tahamtan, Yahya

    2013-01-01

    In this study a disperse dye immunoassay method was standardized and evaluated for detection of antibodies against Neospora caninum in cattle. Sera from 150 cattle with a recent history of abortion were collected and tested by commercial ELISA kit and a standardized in-house dye immunoassay system. The positivity rate for the sera used in this study was 34.6% for the disperse dye immunoassay (DDIA) compared to 32% obtained by ELISA kit. This study showed no significant difference between DDIA and ELISA. The results indicated that the DDIA provide an economic, simple, rapid and robust test for detection of N. caninum infection in cattle. PMID:23467930

  10. Development of a disperse dye immunoassay technique for detection of antibodies against Neospora caninum in cattle.

    PubMed

    Selahi, Fatemeh; Namavari, Mehdi; Hosseini, Mohammad Hossein; Mansourian, Maryam; Tahamtan, Yahya

    2013-02-01

    In this study a disperse dye immunoassay method was standardized and evaluated for detection of antibodies against Neospora caninum in cattle. Sera from 150 cattle with a recent history of abortion were collected and tested by commercial ELISA kit and a standardized in-house dye immunoassay system. The positivity rate for the sera used in this study was 34.6% for the disperse dye immunoassay (DDIA) compared to 32% obtained by ELISA kit. This study showed no significant difference between DDIA and ELISA. The results indicated that the DDIA provide an economic, simple, rapid and robust test for detection of N. caninum infection in cattle. PMID:23467930

  11. Living donor liver transplantation in Egypt

    PubMed Central

    Marwan, Ibrahim

    2016-01-01

    In Egypt there is no doubt that chronic liver diseases are a major health concern. Hepatitis C virus (HCV) prevalence among the 15−59 years age group is estimated to be 14.7%. The high prevalence of chronic liver diseases has led to increasing numbers of Egyptian patients suffering from end stage liver disease (ESLD), necessitating liver transplantation (LT). We reviewed the evolution of LT in Egypt and the current status. A single center was chosen as an example to review the survival and mortality rates. To date, deceased donor liver transplantation (DDLT) has not been implemented in any program though Egyptian Parliament approved the law in 2010. Living donor liver transplantation (LDLT) seemed to be the only logical choice to save many patients who are in desperate need for LT. By that time, there was increase in number of centers doing LDLT (13 centers) and increase in number of LDLT cases [2,400] with improvement of the results. Donor mortality rate is 1.66 per 1,000 donors; this comprised four donors in the Egyptian series. The exact recipient survival is not accurately known however, and the one-year, three-year and five-year survival were 73.17%, 70.83% and 64.16% respectively in the International Medical Center (IMC) in a series of 145 adult to adult living donor liver transplantation (AALDLT) cases. There was no donor mortality in this series. LDLT are now routinely and successfully performed in Egypt with reasonable donor and recipient outcomes. Organ shortage remains the biggest hurdle facing the increasing need for LT. Although LDLT had reasonable outcomes, it carries considerable risks to healthy donors. For example, it lacks cadaveric back up, and is not feasible for all patients. The initial success in LDLT should drive efforts to increase the people awareness about deceased organ donation in Egypt. PMID:27115003

  12. Living donor liver transplantation in Egypt.

    PubMed

    Amer, Khaled E; Marwan, Ibrahim

    2016-04-01

    In Egypt there is no doubt that chronic liver diseases are a major health concern. Hepatitis C virus (HCV) prevalence among the 15-59 years age group is estimated to be 14.7%. The high prevalence of chronic liver diseases has led to increasing numbers of Egyptian patients suffering from end stage liver disease (ESLD), necessitating liver transplantation (LT). We reviewed the evolution of LT in Egypt and the current status. A single center was chosen as an example to review the survival and mortality rates. To date, deceased donor liver transplantation (DDLT) has not been implemented in any program though Egyptian Parliament approved the law in 2010. Living donor liver transplantation (LDLT) seemed to be the only logical choice to save many patients who are in desperate need for LT. By that time, there was increase in number of centers doing LDLT (13 centers) and increase in number of LDLT cases [2,400] with improvement of the results. Donor mortality rate is 1.66 per 1,000 donors; this comprised four donors in the Egyptian series. The exact recipient survival is not accurately known however, and the one-year, three-year and five-year survival were 73.17%, 70.83% and 64.16% respectively in the International Medical Center (IMC) in a series of 145 adult to adult living donor liver transplantation (AALDLT) cases. There was no donor mortality in this series. LDLT are now routinely and successfully performed in Egypt with reasonable donor and recipient outcomes. Organ shortage remains the biggest hurdle facing the increasing need for LT. Although LDLT had reasonable outcomes, it carries considerable risks to healthy donors. For example, it lacks cadaveric back up, and is not feasible for all patients. The initial success in LDLT should drive efforts to increase the people awareness about deceased organ donation in Egypt. PMID:27115003

  13. [Ethical and legal prerequisites of living donors].

    PubMed

    Lilie, H; Krüger, M

    2010-09-01

    Patients in the waiting list die because there are too few postmortem organ donors. A way out of this dilemma would be living donors. The regulations on this in the transplantation act from 1997 are, however, very rudimentary and above all very restrictive. Furthermore, they have been partially superseded by medical advances. This leads to substantial insecurity for transplantation physicians in the practice. This article examines the current law on living donors without being limited solely to it. Furthermore, attempts at reforms will be put forward. PMID:20730410

  14. Reassessing Medical Risk in Living Kidney Donors

    PubMed Central

    Kumar, Vineeta; Matas, Arthur J.

    2015-01-01

    The short- and long-term effects of unilateral nephrectomy on living donors have been important considerations for 60 years. Short-term risk is well established (0.03% mortality and <1% risk of major morbidity), but characterization of long-term risk is evolving. Relative to the general population, risk of mortality, ESRD, hypertension, proteinuria, and cardiovascular disease is comparable or lower. However, new studies comparing previous donors with equally healthy controls indicate increased risk of metabolic derangements (particularly involving calcium homeostasis), renal failure, and possibly, mortality. We discuss how these results should be interpreted and their influence on the practice of living donor kidney transplantation. PMID:25255922

  15. Interventional radiology in living donor liver transplant

    PubMed Central

    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

    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. PMID:24876742

  16. Donor Retention in Online Crowdfunding Communities: A Case Study of DonorsChoose.org

    PubMed Central

    Althoff, Tim; Leskovec, Jure

    2016-01-01

    Online crowdfunding platforms like DonorsChoose.org and Kick-starter allow specific projects to get funded by targeted contributions from a large number of people. Critical for the success of crowdfunding communities is recruitment and continued engagement of donors. With donor attrition rates above 70%, a significant challenge for online crowdfunding platforms as well as traditional offline non-profit organizations is the problem of donor retention. We present a large-scale study of millions of donors and donations on DonorsChoose.org, a crowdfunding platform for education projects. Studying an online crowdfunding platform allows for an unprecedented detailed view of how people direct their donations. We explore various factors impacting donor retention which allows us to identify different groups of donors and quantify their propensity to return for subsequent donations. We find that donors are more likely to return if they had a positive interaction with the receiver of the donation. We also show that this includes appropriate and timely recognition of their support as well as detailed communication of their impact. Finally, we discuss how our findings could inform steps to improve donor retention in crowdfunding communities and non-profit organizations. PMID:27077139

  17. The Medically Complex Living Kidney Donor: Glucose Metabolism as Principal Cause of Donor Declination.

    PubMed

    Guthoff, Martina; Nadalin, Silvio; Fritsche, Andreas; Knigsrainer, Alfred; Hring, Hans-Ulrich; Heyne, Nils

    2016-01-01

    BACKGROUND Transplant centers are increasingly confronted with medically complex living kidney donor candidates. Considerable differences exist among centers regarding handling of these patients and little data is available on characteristics, evaluation outcome and declination criteria. We now demonstrate impaired glucose metabolism to be the largest single cause of donor declination. MATERIAL AND METHODS Follow-up of 133 donor-recipient pairs, presenting to our transplant center between 03/2007 and 06/2012 was included in the analysis. Evaluation outcome of donor-recipient pairs was assessed and declinations stratified into donor or recipient reasons and underlying conditions. RESULTS 65 donor-recipient pairs (49%) were accepted for transplantation, 68 (51%) were declined upon first evaluation. 77% of declinations were for donor- and 23% for recipient reasons. Almost half of donor declinations resulted from increased cardiovascular risk with the presence of diabetes mellitus or prediabetes as the largest single cause of declination. CONCLUSIONS Glucose metabolism is key in donor risk assessment and precludes kidney donation if abnormal. The high prevalence emphasizes the need for prevention. Prediabetes defines a cohort at risk and response to lifestyle intervention allows for individual risk stratification, thereby potentially increasing the number of persons eligible for kidney donation. Unification of evaluation criteria, as well as prospective long-term follow-up is required to account for increasingly complex living kidney donors. PMID:26811295

  18. Responses to recipient and donor B cells by genetically donor T cells from human haploidentical chimeras

    SciTech Connect

    Schiff, S.; Sampson, H.; Buckley, R.

    1986-03-01

    Following administration of haploidentical stem cells to infants with severe combined immunodeficiency (SCID), mature T cells of donor karyotype appear later in the recipient without causing graft-versus-host disease. To investigate the effect of the host environment on the responsiveness of these genetically donor T cells, blood B and T lymphocytes from 6 SCID recipients, their parental donors and unrelated controls were purified by double SRBC rosetting. T cells were stimulated by irradiated B cells at a 1:1 ratio in 6 day cultures. Engrafted T cells of donor karyotype gave much smaller responses to irradiated genetically recipient B cells than did fresh donor T cells. Moreover, engrafted T cells of donor karyotype from two of the three SCIDs who are longest post-transplantation responded more vigorously (14,685 and 31,623 cpm) than fresh donor T cells (5141 and 22,709 cpm) to donor B cells. These data indicate that T lymphocytes which have matured from donor stem cells in the recipient microenvironment behave differently from those that have matured in the donor.

  19. Phonon induced spin relaxation times of single donors and donor clusters in silicon

    NASA Astrophysics Data System (ADS)

    Hsueh, Yuling; Buch, Holger; Hollenberg, Lloyd; Simmons, Michelle; Klimeck, Gerhard; Rahman, Rajib

    2014-03-01

    The phonon induced relaxation times (T1) of electron spins bound to single phosphorous (P) donors and P donor clusters in silicon is computed using the atomistic tight-binding method. The electron-phonon Hamiltonian is directly computed from the strain dependent tight-binding Hamiltonian, and the relaxation time is computed from Fermi's Golden Rule using the donor states and the electron-phonon Hamiltonian. The self-consistent Hartree method is used to compute the multi-electron wavefunctions in donor clusters. The method takes into account the full band structure of silicon including the spin-orbit interaction, and captures both valley repopulation and single valley g-factor shifts in a unified framework. The single donor relaxation rate varies proportionally to B5, and is of the order of seconds at B =2T, both in good agreement with experimental single donor data (A. Morello et. al., Nature 467, 687 (2010)). T1 calculations in donor clusters show variations for different electron numbers and donor numbers and locations. The computed T1 in a 4P:5e donor cluster match well with a scanning tunneling microscope patterned P donor cluster (H. Buch et. al., Nature Communications 4, 2017 (2013)).

  20. The effect of donor characteristics on survival after unrelated donor transplantation for hematologic malignancy.

    PubMed

    Kollman, Craig; Spellman, Stephen R; Zhang, Mei-Jie; Hassebroek, Anna; Anasetti, Claudio; Antin, Joseph H; Champlin, Richard E; Confer, Dennis L; DiPersio, John F; Fernandez-Viña, Marcelo; Hartzman, Robert J; Horowitz, Mary M; Hurley, Carolyn K; Karanes, Chatchada; Maiers, Martin; Mueller, Carlheinz R; Perales, Miguel-Angel; Setterholm, Michelle; Woolfrey, Ann E; Yu, Neng; Eapen, Mary

    2016-01-14

    There are >24 million registered adult donors, and the numbers of unrelated donor transplantations are increasing. The optimal strategy for prioritizing among comparably HLA-matched potential donors has not been established. Therefore, the objective of the current analyses was to study the association between donor characteristics (age, sex, parity, cytomegalovirus serostatus, HLA match, and blood group ABO match) and survival after transplantation for hematologic malignancy. The association of donor characteristics with transplantation outcomes was examined using either logistic or Cox regression models, adjusting for patient disease and transplantation characteristics associated with outcomes in 2 independent datasets: 1988 to 2006 (N = 6349; training cohort) and 2007 to 2011 (N = 4690; validation cohort). All donor-recipient pairs had allele-level HLA typing at HLA-A, -B, -C, and -DRB1, which is the current standard for selecting donors. Adjusting for patient disease and transplantation characteristics, survival was better after transplantation of grafts from young donors (aged 18-32 years) who were HLA matched to recipients (P < .001). These findings were validated for transplantations that occurred between 2007 and 2011. For every 10-year increment in donor age, there is a 5.5% increase in the hazard ratio for overall mortality. Increasing HLA disparity was also associated with worsening survival. Donor age and donor-recipient HLA match are important when selecting adult unrelated donors. Other donor characteristics such as sex, parity, and cytomegalovirus serostatus were not associated with survival. The effect of ABO matching on survival is modest and must be studied further before definitive recommendations can be offered. PMID:26527675

  1. Determination of dihydroergosine in sorghum ergot using an immunoassay.

    PubMed

    Molloy, John B; Moore, Chris J; Bruyeres, Anthea G; Murray, Sally-Ann; Blaney, Barry J

    2003-07-01

    Dihydroergosine (DHES) is the principal toxic alkaloid produced by sorghum ergot (Claviceps africana). It has recently been shown that DHES levels as low as 1 mg/kg in animal feed can cause significant production losses. Quantitative immunoassays for detecting the related rye ergot alkaloid, ergotamine, are described in the literature, but those assays are relatively insensitive for DHES. This paper describes competitive enzyme-linked immunosorbent assays (ELISA) for measuring the DHES concentration in grains and mixed animal feed. The assays were developed using a DHES specific mouse monoclonal antibody and rabbit polyclonal antibodies raised against DHES conjugated to bovine serum albumin. Recoveries of between 77 and 103% were obtained from spiked grain using a simple, one step extraction with 70% methanol. Both the monoclonal and the polyclonal assays are capable of detecting DHES concentrations above 0.01 mg/kg, but quantification is most reliable at concentrations of 0.1 mg/kg or higher. PMID:12822923

  2. Spectral interferometric immunoassay with synthetic lipid-anchored polypeptide antigens

    NASA Astrophysics Data System (ADS)

    Brecht, Andreas; Gauglitz, Guenter; Beck, Werner; Spohn, Renate; Jung, Guenter

    1993-04-01

    Spectral interferometric investigations, which were carried out at thin dielectric layers with a novel fixation procedure for synthetic antigens, are reported. This work is aimed at an optical, regenerable, label-free immunosensor for antibody determinations. Most optical biosensor approaches require fixation of some kind of receptor to the sensor surface. Simple adsorption leads to washout effects and often prohibits sensor regeneration. Covalent fixation usually decreases receptor affinity significantly. In this paper we report a noncovalent fixation procedure, based on synthetic, lipid anchored peptide antigens. Fixation is achieved by strong hydrophobic interaction between the pretreated sensor surface and a lipid anchor covalently linked to the antigen. Spectral interferometry uses short coherent (white) light interference for the determination of surface and volume effects at thin films. This method has been successfully applied to hydrocarbon sensing and solid phase adsorption immunoassay.

  3. Chemiluminescence enzyme immunoassay for the determination of sulfamethoxydiazine

    NASA Astrophysics Data System (ADS)

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

    2011-10-01

    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.

  4. IgE Epitope Mapping Using Peptide Microarray Immunoassay.

    PubMed

    Gimenez, Gustavo; Benedé, Sara; Lin, Jing

    2016-01-01

    IgE epitope mapping of food allergens contributes to a better understanding of the pathogenesis of food allergy and may become an additional tool for food allergy diagnosis/prognosis. Microarray platforms which allow for simultaneous screening of a large number of peptides corresponding to the sequences of food allergens are ideally suited for large-scale IgE epitope mapping. Here we describe the method of performing a reliable and sensitive peptide microarray immunoassay, which was developed in our lab and results in the identification of candidate IgE epitope biomarkers useful in determining allergic disease severity and prognosis, as well as in the prediction of treatment outcomes. A gastric digestion model that can be applied to prescreen peptides and reduce costs in the peptide microarray is also described in this chapter. PMID:26490481

  5. Quantitative evaluation of magnetic immunoassay with remanence measurement

    NASA Astrophysics Data System (ADS)

    Enpuku, K.; Soejima, K.; Nishimoto, T.; Kuma, H.; Hamasaki, N.; Tsukamoto, A.; Saitoh, K.; Kandori, A.

    2006-05-01

    Magnetic immunoassays utilizing magnetic markers and a high -Tc SQUID have been performed. The marker was designed so as to generate remanence, and its remanence field was measured with the SQUID. The SQUID system was developed so as to measure 12 samples in one measurement sequence. We first conducted a detection of antigen called human IgE using IgE standard solution, and showed the detection of IgE down to 2 attomol. The binding process between IgE and the marker could be semi-quantitatively explained with the Langmuir-type adsorption model. We also measured IgE in human serums, and demonstrated the usefulness of the present method for practical diagnosis.

  6. Bacterial Magnetic Nanoparticles as Peroxidase Mimetics and Application in Immunoassay

    NASA Astrophysics Data System (ADS)

    Hu, Lili; Song, Tao; Ma, Qiufeng; Chen, Chuanfang; Pan, Weidong; Xie, Chunlan; Nie, Leng; Yang, Wenhui

    2010-12-01

    Although progress in nanosynthesis has succeeded in making nanoscale particles from iron oxide, the research about natural magnetic nanoparticles, magnetosomes, is still a current interest because of their intrinsic magnetic features, nano-features, membrane-enclosed features and genetic control of size and morphology properties. In this study, we investigated magnetosomes' intrinsic peroxidase-like activity similar to that found in artificial magnetic nanoparticles. We characterized the catalytic activity by varying the method of extraction and storage, the pH value, the temperature and the H2O2 concentration. Based on these finding, we developed a simplified immunoassay approach to use magnetosomes as a peroxidase mimic catalyst and a magnetic separator as well.

  7. Liquid Phase Immunoassay Using AC Susceptibility Measurement of Magnetic Markers

    NASA Astrophysics Data System (ADS)

    Enpuku, Keiji; Tamai, Yuya; Mitake, Tetsu; Matsuo, Masaaki; Tsukamoto, Akira; Mizoguchi, Takako; Kandori, Akihiko

    2009-03-01

    AC susceptibility measurement of magnetic markers in solution was applied to biological immunoassays. In this method, the markers that bound to biological target can be detected in the presence of unbound markers. The bound markers were distinguished from the unbound ones by using their different frequency dependence of susceptibility. We detected biotin-conjugated polymer beads with avidin-coated Fe3O4 markers. Changes of the susceptibility caused by the binding reaction between them were shown. Good relationship was obtained between the decrease of susceptibility and the number of polymer beads. Sensitivity of the system was estimated as 3×10-16 mol/ml in terms of molecular-number concentration.

  8. Development of an Ultrasensitive Immunoassay for Detecting Tartrazine

    PubMed Central

    Li, Zhuokun; Song, Shanshan; Xu, Liguang; Kuang, Hua; Guo, Shidong; Xu, Chuanlai

    2013-01-01

    We have developed an ultrasensitive indirect competitive enzyme-linked immunosorbent assay for the determination of tartrazine. Two carboxylated analogues of tartrazine with different spacer lengths, and one derivative from commercial tartrazine after a little chemical modification, were synthesized as haptens in order to produce antibodies specific to tartrazine. The effect of sulfonic acid groups on the hapten structure of tartrazine was also studied carefully for the first time. A most specific monoclonal antibody against tartrazine was created and exhibited an IC50 value of 0.105 ng/mL and a limit of detection of 0.014 ng/mL, with no cross-reactivity to other structurally-related pigments. The established immunoassay was applied to the determination of tartrazine in fortified samples of orange juice and in real positive samples of carbonated beverages. PMID:23799494

  9. Biosensor immunoassay for traces of hazelnut protein in olive oil

    PubMed Central

    Smits, Nathalie G. E.; Haasnoot, Willem

    2009-01-01

    The fraudulent addition of hazelnut oil to more expensive olive oil not only causes economical loss but may also result in problems for allergic individuals as they may inadvertently be exposed to potentially allergenic hazelnut proteins. To improve consumer safety, a rapid and sensitive direct biosensor immunoassay, based on a highly specific monoclonal antibody, was developed to detect the presence of hazelnut proteins in olive oils. The sample preparation was easy (extraction with buffer); the assay time was fast (4.5 min only) and the limit of detection was low (0.08 μg/g of hazelnut proteins in olive oil). Recoveries obtained with an olive oil mixed with different amounts of a hazelnut protein containing hazelnut oil varied between 93% and 109%. Electronic supplementary material The online version of this article (doi:10.1007/s00216-009-2720-1) contains supplementary material, which is available to authorized users. PMID:19263041

  10. Nanoparticle-based immunosensors and immunoassays for aflatoxins.

    PubMed

    Wang, Xu; Niessner, Reinhard; Tang, Dianping; Knopp, Dietmar

    2016-03-17

    Aflatoxins are naturally existing mycotoxins produced mainly by Aspergillus flavus and Aspergillus parasiticus, present in a wide range of food and feed products. Because of their extremely high toxicity and carcinogenicity, strict control of maximum residue levels of aflatoxins in foodstuff is set by many countries. In daily routine, different chromatographic methods are used almost exclusively. As supplement, in several companies enzyme immunoassay-based sample testing as primary screening is performed. Recently, nanomaterials such as noble metal nanoparticles, magnetic particles, carbon nanomaterials, quantum dots, and silica nanomaterials are increasingly utilized for aflatoxin determination to improve the sensitivity and simplify the detection. They are employed either as supports for the immobilization of biomolecules or as electroactive or optical labels for signal transduction and amplification. Several nanoparticle-based electrochemical, piezoelectric, optical, and immunodipstick assays for aflatoxins have been developed. In this review, we summarize these recent advances and illustrate novel concepts and promising applications in the field of food safety. PMID:26920768

  11. Gold bands as a suitable surface for enzyme immunoassays.

    PubMed

    Abad-Villar, Eva M; Fernndez-Abedul, M Teresa; Costa-Garca, Agustn

    2002-09-01

    Gold bands sputtered over a polymeric material, Kapton, are employed for the development of enzyme immunoassays. The immunological interaction takes place between human IgM and alkaline phosphatase (AP) conjugated anti-IgM. The model analyte (IgM) could be determined following a non-competitive design in the range of 0.05-5 ppm, with a limit of detection of 50 ppb. After the interaction, gold bands are sequentially inserted in a flow system and the extension of the reaction is followed through the enzymatic hydrolysis of naphthylphosphate, AP substrate. The product, naphthol, is oxidised to naphtoquinone in the gold band of the flow cell that constitutes the detector. Parameters affecting the interaction are studied and calibration curves are performed. The reproducibility between different bands (RSD=4%, n=5) and possibilities of regeneration are also detailed. PMID:12191928

  12. The development of immunoassays for detection of chemical warfare agents

    SciTech Connect

    Lenz, D.E.; Brimfield, A.A.; Cook, L.

    1996-10-01

    With the advent of enzyme linked immunoabsorbent assays (ELISA) and monoclonal antibodies in the last two decades, there has been considerable effort devoted to the development of antibodies to detect and quantify low molecular weight toxic substances in environmental or biological fluids. Polyclonal antibodies against paraoxon (the toxic metabolite of parathion) were capable of detecting paraoxon in body fluids at a level of 10{sup -9} M ({approximately}260 pg/mL) when used in a competitive inhibition enzyme immunoassay (CIEIA). Monoclonal antibodies developed against a structural analogue of the chemical warfare agent soman were capable of detection soman in buffer solutions at a level of 10{sup -6} M ({approximately}180 ng/mL). In addition these antibodies were found to be highly specific for soman even in the presence of its major hydrolysis product. Subsequent studies with antisoman monoclonal antibodies extended the level of sensitivity to {approximately}80 ng/mL. Furthermore these antibodies did not cross react with other chemical warfare nerve agents such as sarin or tabun. In all cases, the time for a confirmatory test was two hours or less. Immunoassays for T-2 micotoxins have also been reported with a minimal detection range of 2 pg/assay to 50 ng/assay for the polyclonal and monoclonal T-2 antibodies respectively. These reagents offer a sensitive, rapid and low cost approach to the diagnosis or detection of the presence of toxic chemical substances. More recent efforts have focussed on developing antibodies specific for sulfur mustard a highly reactive vesicating agent.

  13. Development of immunoassays for biomonitoring of hexamethylene diisocyanate exposure.

    PubMed Central

    Lemus, R; Lukinskeine, L; Bier, M E; Wisnewski, A V; Redlich, C A; Karol, M H

    2001-01-01

    Hexamethylene diisocyanate (HDI) is used widely to manufacture polyurethanes for paints and coatings. It is an irritant and a chemical asthmagen. The U.S. Occupational Safety and Health Administration time-weighted average permissible exposure limit is 5 ppb and the ceiling limit is 20 ppb. We sought to develop a sensitive and specific immuno-bioassay to supplement workplace air monitoring and detect recent HDI exposure. For this, we produced rabbit antiserum to HDI-adducted keyhole limpet hemocyanin (HDI-KLH). The specificity of the antiserum was demonstrated by its reaction with a variety of HDI-conjugated proteins and the absence of reactions with conjugates of other diisocyanates, namely toluene diisocyanate and diphenyl methylene diisocyanate. Four immunoassays were developed and compared for their ability to detect decreasing quantities of HDI-adducted human serum albumin (HSA) containing 2 mol HDI adduct per mol HSA (HDI(2)-HSA) as determined by matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry. The sensitivities of some of the assays are within the range (0.82-45 nM) of current analytic methods. A Western analysis procedure has a sensitivity of 600 nM HDI adduct on HSA. ELISA inhibition assay, in which microtiter plates are coated with the HDI(2)-HSA antigen, has a sensitivity of 300 nM HDI adduct. An immunoblot assay has a sensitivity of 9 nM HDI adduct. The most sensitive bioassay (1.8 nM HDI adduct) is a three-antibody sandwich ELISA in which wells of microtiter plates are coated with the IgG fraction of the anti-HDI-KLH antisera. Compared with analytic methods for HDI biomonitoring, the immunoassays are faster and less costly and accommodate numerous samples simultaneously. The assays have the potential to affect industrial biomonitoring programs significantly. PMID:11712993

  14. Fluorescence immunoassay for detecting periodontal bacterial pathogens in plaque.

    PubMed Central

    Wolff, L F; Anderson, L; Sandberg, G P; Aeppli, D M; Shelburne, C E

    1991-01-01

    A particle concentration fluorescence immunoassay has been modified into a bacterial concentration fluorescence immunoassay (BCFIA) to rapidly detect periodontopathic bacteria in human plaque samples. The BCFIA utilizes fluorescently tagged monoclonal antibodies (MAbs) directed against the lipopolysaccharide of selected gram-negative plaque bacteria. Microorganisms closely associated with periodontal disease that can be identified in plaque with the BCFIA include Porphyromonas gingivalis, Bacteroides intermedius, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Eikenella corrodens. Briefly, the procedure involved mixing a patient's plaque sample or other bacterial preparation with a species-specific fluorescein isothiocyanate-labeled MAb in a specialized microtiter plate. This mixture was incubated to allow binding of the MAb to its homologous bacteria. The bound and unbound fluorescent tagged MAbs were separated by filtration in the modified microtiter plate, and the total bacterial bound fluorescence was determined with a fluorimeter. The number of a specific bacterial species in a given plaque sample or other bacterial suspension was estimated by reference to a primary standard carried through the BCFIA. The lower detection limit of the BCFIA was 10(3) to 10(4) bacterial cells from single cultures of bacteria or 10(4) bacterial cells in mixed cultures. The coefficient of variation within and between plates for each of the five bacterium-specific MAbs in screening plaque for the periodontal pathogens was less than 10%. These results demonstrate that microbes in plaque can be used as the solid phase in the BCFIA to detect and quantitate MAbs associated with specific bacteria quickly and reliably. PMID:1761686

  15. Multiplexed magnetic microsphere immunoassays for detection of pathogens in foods

    PubMed Central

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

    2010-01-01

    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. PMID:20953301

  16. Living donor liver transplantation in the USA

    PubMed Central

    Testa, Giuliano

    2016-01-01

    Living donor liver transplant (LDLT) accounts for a small volume of the transplants in the USA. Due to the current liver allocation system based on the model for end-stage liver disease (MELD), LDLT has a unique role in providing life-saving transplantation for patients with low MELD scores and significant complications from portal hypertension, as well as select patients with hepatocellular carcinoma (HCC). Donor safety is paramount and has been a topic of much discussion in the transplant community as well as the general media. The donor risk appears to be low overall, with a favorable long-term quality of life. The latest trend has been a gradual shift from right-lobe grafts to left-lobe grafts to reduce donor risk, provided that the left lobe can provide adequate liver volume for the recipient. PMID:27115007

  17. Solicited kidney donors: Are they coerced?

    PubMed Central

    SERUR, DAVID; BRETZLAFF, GRETCHEN; CHRISTOS, PAUL; DESROSIERS, FARRAH; CHARLTON, MARIAN

    2016-01-01

    Most non-directed donors (NDDs) decide to donate on their own and contact the transplant centre directly. Some NDDs decide to donate in response to community solicitation such as newspaper ads or donor drives. We wished to explore whether subtle coercion might be occurring in such NDDs who are part of a larger community. One successful organization in a community in Brooklyn, NY, provides about 50 NDDs per year for recipients within that community. The donors answer ads in local papers and attend donor drives. Herein, we evaluated the physical and emotional outcomes of community-solicited NDDs in comparison to traditional NDDs who come from varied communities and are not responding to a specific call for donation. An assessment of coercion was used as well. PMID:26511772

  18. Non-organ donors' attitudes toward incentives.

    PubMed

    Tumin, Makmor; Noh, Abdillah; Chong, Chin-Sieng; Lim, Soo-Kun; Abdullah, Nawi; Ng, Kok-Peng

    2013-01-01

    Malaysians indicating that they did not intend to become organ donors upon their death were surveyed regarding interest in non-fungible financial incentives to be granted to surviving family members. Among the 730 (56% of the total sample of 1311) indicating unwillingness to be donors, 29.6% (216/730) subsequently indicated that they would be willing donors if the government introduced policies that, upon their death, "rewarded your (their) family with incentives for your (their) deeds." Among the 69% (504/730) who insisted that they would not become organ donor even with incentive, nearly 80% (404/501) of them were able to identify relevant incentives they thought should be provided by the state to those who make organ donations upon death. The majority of both groups preferred the state provide medical benefits to a surviving family member, suggesting this may be an attractive policy option for the state to raise the deceased organ donation pool. PMID:23600843

  19. Iron status of regular voluntary blood donors

    PubMed Central

    Mahida, Vilsu I.; Bhatti, Apksha; Gupte, Snehalata C.

    2008-01-01

    Background: Our blood bank is a regional blood transfusion centre, which accepts blood only from voluntary donors. Aim: The aim is to study iron status of regular voluntary donors who donated their blood at least twice in a year. Materials and Methods: Prior to blood donation, blood samples of 220 male and 30 female voluntary donors were collected. Control included 100 each male and female healthy individuals in the 18- to 60-year age group, who never donated blood and did not have any chronic infection. In the study and control groups, about 10% subjects consumed non-vegetarian diet. After investigation, 85 males and 56 females having haemoglobin (Hb) levels above 12.5 g/dl were selected as controls. Donors were divided into ?10, 11-20, 21-50 and >50 blood donation categories. Majority of the donors in >50 donation category donated blood four times in a year, whereas the remaining donors donated two to three times per year. Haematological parameters were measured on fully automatic haematology analyzer, serum iron and total iron-binding capacity (TIBC) by biochemical methods, ferritin using ELISA kits and transferrin using immunoturbidometry kits. Iron/TIBC ratio 100 gave percentage of transferrin saturation value. Statistical Analysis: Statistical evaluation was done by mean, standard deviation, pair t-test, ?2 and anova (F-test). Results: Preliminary analysis revealed that there was no significant difference in the iron profile of vegetarian and non-vegetarian subjects or controls and the donors donating <20 times. Significant increase or decrease was observed in mean values of various haematological and iron parameters in donors who donated blood for >20 times (P < 0.001), compared to controls. Anaemia, iron deficiency and depletion of iron stores were more prevalent in female donors (P < 0.05) compared to males and especially in those male donors who donated their blood for more than 20 times. Conclusion: Regular voluntary blood donors should receive iron supplementation to prevent iron deficiency and depletion in iron stores. PMID:20041071

  20. Donor insemination in Israel: sociodemographic aspects.

    PubMed

    Carmeli, Y S; Carmeli, D B; Matilsky YSM; Kalderon, I; Yavetz, H

    2001-04-01

    The paper describes the sociodemography of donor insemination recipients in Israel. Arab recipients are very few. Among the Jews, married recipients are generally younger than their single counterparts, and they are somewhat less educated and more religious. Ethnically, the percentage of Orientals among the married recipients is relatively higher; among the single women, Orientals are under-represented. On the whole, however, donor insemination seems to have reached Jewish Israelis of all segments of society. PMID:11284634

  1. Chemiluminescence enzyme immunoassay using magnetic nanoparticles for detection of neuron specific enolase in human serum.

    PubMed

    Fu, Xiaoling; Meng, Meng; Zhang, Yu; Yin, Yongmei; Zhang, Xiangsheng; Xi, Rimo

    2012-04-13

    To detect a biomarker for small cell lung carcinoma, neuron specific enolase (NSE), a sensitive and specific chemiluminescence enzyme immunoassay was developed. Fluorescein isothiocyanate (FITC) labeled NSE capture antibody connected with NSE and alkaline phosphatase (ALP) labeled NSE detection antibody in a sandwich-type detection manner. This immune complex was further reacted with anti-FITC coated magnetic beads. In a magnetic field, the complex was enriched, and the sensitivity was thus enhanced. The limit of detection (LOD) of this method was <0.2 ng mL(-1). The proposed immunoassay was highly selective, and not interfered by hook effect. The recovery was >83.0% and the coefficient of variation was <10.0%. Human sera from 120 patients were tested with the presented and traditional chemiluminescence enzyme immunoassay. An excellent linear relationship was obtained between two techniques. Overall, this immunoassay offers a promising alternative for NSE detection than traditional clinical examinations. PMID:22444542

  2. An inexpensive, fast and sensitive quantitative lateral flow magneto-immunoassay for total prostate specific antigen.

    PubMed

    Barnett, Jacqueline M; Wraith, Patrick; Kiely, Janice; Persad, Raj; Hurley, Katrina; Hawkins, Peter; Luxton, Richard

    2014-09-01

    We describe the detection characteristics of a device the Resonant Coil Magnetometer (RCM) to quantify paramagnetic particles (PMPs) in immunochromatographic (lateral flow) assays. Lateral flow assays were developed using PMPs for the measurement of total prostate specific antigen (PSA) in serum samples. A detection limit of 0.8 ng/mL was achieved for total PSA using the RCM and is at clinically significant concentrations. Comparison of data obtained in a pilot study from the analysis of serum samples with commercially available immunoassays shows good agreement. The development of a quantitative magneto-immunoassay in lateral flow format for total PSA suggests the potential of the RCM to operate with many immunoassay formats. The RCM has the potential to be modified to quantify multiple analytes in this format. This research shows promise for the development of an inexpensive device capable of quantifying multiple analytes at the point-of-care using a magneto-immunoassay in lateral flow format. PMID:25587419

  3. An Inexpensive, Fast and Sensitive Quantitative Lateral Flow Magneto-Immunoassay for Total Prostate Specific Antigen

    PubMed Central

    Barnett, Jacqueline M.; Wraith, Patrick; Kiely, Janice; Persad, Raj; Hurley, Katrina; Hawkins, Peter; Luxton, Richard

    2014-01-01

    We describe the detection characteristics of a device the Resonant Coil Magnetometer (RCM) to quantify paramagnetic particles (PMPs) in immunochromatographic (lateral flow) assays. Lateral flow assays were developed using PMPs for the measurement of total prostate specific antigen (PSA) in serum samples. A detection limit of 0.8 ng/mL was achieved for total PSA using the RCM and is at clinically significant concentrations. Comparison of data obtained in a pilot study from the analysis of serum samples with commercially available immunoassays shows good agreement. The development of a quantitative magneto-immunoassay in lateral flow format for total PSA suggests the potential of the RCM to operate with many immunoassay formats. The RCM has the potential to be modified to quantify multiple analytes in this format. This research shows promise for the development of an inexpensive device capable of quantifying multiple analytes at the point-of-care using a magneto-immunoassay in lateral flow format. PMID:25587419

  4. Curved Oligophenylenes as Donors in Shape-Persistent Donor-Acceptor Macrocycles with Solvatofluorochromic Properties.

    PubMed

    Kuwabara, Takuya; Orii, Jun; Segawa, Yasutomo; Itami, Kenichiro

    2015-08-10

    Many optoelectronic organic materials are based on donor-acceptor (D-A) systems with heteroatom-containing electron donors. Herein, we introduce a new molecular design for all-carbon curved oligoparaphenylenes as donors, which results in the generation of unique shape-persistent D-A macrocycles. Two types of acceptor-inserted cycloparaphenylenes were synthesized. These macrocycles display positive solvatofluorochromic properties owing to their D-A characteristics, which were confirmed by theoretical and electrochemical studies. PMID:26140706

  5. Predictors of donor follow-up after living donor liver transplantation.

    PubMed

    Brown, Robert S; Smith, Abigail R; Dew, Mary Amanda; Gillespie, Brenda W; Hill-Callahan, Peg; Ladner, Daniela P

    2014-08-01

    Donor safety in living liver donation is of paramount importance; however, information on long-term outcomes is limited by incomplete follow-up. We sought to ascertain factors that predicted postdonation follow-up in 456 living liver donors in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study. Completed donor follow-up was defined as physical, phone, or laboratory contact at a given time point. Univariate and multivariate mixed effects logistic regression models, using donor and recipient demographic and clinical data and donor quality-of-life data, were developed to predict completed follow-up. Ninety percent of the donors completed their follow-up in the first 3 months, and 83% completed their follow-up at year 1; rates of completed follow-up ranged from 57% to 72% in years 2 to 7 and from 41% to 56% in years 8 to 10. The probability of completed follow-up in the first year was higher for white donors [odds ratio (OR) = 3.27, 95% confidence interval (CI) = 1.25-8.58] but lower for donors whose recipients had hepatitis C virus or hepatocellular carcinoma (OR = 0.34, 95% CI = 0.17-0.69). After the first year, an older age at donation predicted more complete follow-up. There were significant center differences at all time points (OR range = 0.29-10.11), with center variability in both returns for in-center visits and the use of phone/long-distance visits. Donor follow-up in the first year after donation was excellent but decreased with time. Predictors of follow-up varied with the time since donation. In conclusion, adapting best center practices (enhanced through the use of telephones and social media) to maintain contact with donors represents a significant opportunity to gain valuable information about long-term donor outcomes. PMID:24824858

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

    PubMed

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

    2011-06-01

    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

  7. Sperm donors describe the experience of contact with their donor-conceived offspring

    PubMed Central

    Hertz, R.; Nelson, M.K.; Kramer, W.

    2015-01-01

    This study explores the attitudes and experiences of 57 sperm donors who responded to a survey posted online in the United States and indicated that they had had contact with their donor-conceived offspring or the parents of their donor-conceived offspring. On average, 18 years had elapsed since the respondents donated sperm. In the interim between donating and having contact with offspring, most had become curious about their offspring. Most made contact through a bank or online registry. Most respondents had communicated with at least one offspring at least once and most had exchanged photos with offspring. Approximately two-thirds had met in person once; the same proportion had communicated over email or text. Other forms of communication were less common. Almost half of the respondents now considered their donor-conceived offspring to be like a family member. At the same time, donors are respectful of the integrity of the family in which their offspring were raised. Donors with contact are open to having their partners and children know their donor-conceived offspring. Although contact is generally positive, donors report that establishing boundaries and defining the relationship can be very difficult. Some donors also urge those who are thinking of donating to consider the consequences and some suggest avoiding anonymity. There were no significant differences in attitudes and experiences between those who donated anonymously and those who had been identity-release for their offspring when they turned 18. PMID:26175887

  8. The national marrow donor program 20 years of unrelated donor hematopoietic cell transplantation.

    PubMed

    Ballen, Karen K; King, Roberta J; Chitphakdithai, Pintip; Bolan, Charles D; Agura, Edward; Hartzman, Robert J; Kernan, Nancy A

    2008-09-01

    In the 20 years since the National Marrow Donor Program (NMDP) facilitated the first unrelated donor transplant, the organization has grown to include almost 7 million donors, and has facilitated over 30,000 transplants on 6 continents. This remarkable accomplishment has been facilitated by the efforts of over 600 employees, and an extensive international network including 171 transplant centers, 73 donor centers, 24 cord blood banks, 97 bone marrow collection centers, 91 apheresis centers, 26 HLA typing laboratories, and 26 Cooperative Registries. In this article, we review the history of the NMDP, and cite the major trends in patient demographics, graft sources, and conditioning regimens over the last 20 years. PMID:18721774

  9. An analysis of the lack of donor pancreas utilization from younger adult organ donors.

    PubMed

    Wiseman, Alexander C; Wainright, Jennifer L; Sleeman, Elizabeth; McBride, Maureen A; Baker, Tim; Samana, Ciara; Stock, Peter

    2010-09-15

    Donor pancreas utilization rates for whole organ transplant have remained low and have decreased over time. To identify the reasons for nonuse of pancreas from donors who meet common baseline acceptance criteria, we examined Organ Procurement and Transplantation Network data from 2005 to 2007 and identified a subgroup of 1763 "potential pancreas donors" defined by age (19-40 years), body mass index (<30 kg/m), successful liver donation, and negative viral serology testing, which were not used. We characterize this cohort of potential donors including reasons for refusal, factors that may contribute to pancreas acceptance and function, and potential explanations for the lack of growth in pancreas organ utilization. PMID:20595930

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

    PubMed Central

    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

    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. PMID:25032095

  11. Sperm donors describe the experience of contact with their donor-conceived offspring.

    PubMed

    Hertz, R; Nelson, M K; Kramer, W

    2015-01-01

    This study explores the attitudes and experiences of 57 sperm donors who responded to a survey posted online in the United States and indicated that they had had contact with their donor-conceived offspring or the parents of their donor-conceived offspring. On average, 18 years had elapsed since the respondents donated sperm. In the interim between donating and having contact with offspring, most had become curious about their offspring. Most made contact through a bank or online registry. Most respondents had communicated with at least one offspring at least once and most had exchanged photos with offspring. Approximately two-thirds had met in person once; the same proportion had communicated over email or text. Other forms of communication were less common. Almost half of the respondents now considered their donor-conceived offspring to be like a family member. At the same time, donors are respectful of the integrity of the family in which their offspring were raised. Donors with contact are open to having their partners and children know their donor-conceived offspring. Although contact is generally positive, donors report that establishing boundaries and defining the relationship can be very difficult. Some donors also urge those who are thinking of donating to consider the consequences and some suggest avoiding anonymity. There were no significant differences in attitudes and experiences between those who donated anonymously and those who had been identity-release for their offspring when they turned 18. PMID:26175887

  12. Human T-Lymphotropic Virus Type 1 and 2 Seroprevalence among first-time blood donors in Chile, 2011-2013.

    PubMed

    San Martín, Héctor; Balanda, Monserrat; Vergara, Nicolás; Valenzuela, María Antonieta; Cartier, Luis; Ayala, Salvador; Ramírez, Eugenio

    2016-06-01

    Infection with human T-lymphotropic virus type 1/2 (HTLV-1/2) is a major health problem. HTLV-1/2 infection is endemic in Chile but representative donor prevalence data are lacking. Data on all blood donors in a large network of Chilean blood centers were examined during 2011-2013. Screening of HTLV-1/2 antibodies were measured by enzyme immunoassay (EIA) at all blood banks. Blood samples with anticoagulants from initially reactive blood donors were analyzed by serological confirmation tests (immunofluorescence or recombinant immunoblot) at the HTLV National Reference Laboratory of the Public Health Institute of Chile. Additionally, detection of HTLV-1 and HTLV-2 provirus in peripheral blood mononuclear cells (PBMCs) was performed in all blood donors as confirmatory test. Prevalence rates were calculated. Among 694,016 donors, 706 were seropositive for HTLV-1 (prevalence, 1.02 cases per 1,000; 95% confidence interval [CI], 0.94-1.09), and 97 were seropositive for HTLV-2 (prevalence, 0.14 cases per 1,000; 95%CI, 0.11-0.17). Prevalence of HTLV-1 differed considerably by region, from 0.51 to 1.69 per 1,000. Prevalence of HTLV-2 was similar across the country (0.12-0.16). HTLV-1 prevalence was associated with female sex, older age, and residence in the north of Chile. HTVL-2 prevalence was associated with older age. The HTLV-1 prevalence among Chilean blood donors was relatively high and could be reduced by improving donor recruitment and selection in high prevalence areas. Blood center data may contribute to surveillance for HTLV-1 and HTLV-2 infections. J. Med. Virol. 88:1067-1075, 2016. © 2015 Wiley Periodicals, Inc. PMID:26538335

  13. A pattern of 5-1-1 and c100-3 only on hepatitis C virus (HCV) recombinant immunoblot assay does not reflect HCV infection in blood donors.

    PubMed

    Busch, M P; Tobler, L; Quan, S; Wilber, J C; Johnson, P; Polito, A; Steane, E; Zola, A; Bahl, C; Nelles, M

    1993-01-01

    Current criteria for a reactive (positive) interpretation on hepatitis C virus (HCV) recombinant immunoblot assay (RIBA) require > or = 1+ reactivity to at least two of the four HCV antigens present in the assay. Given that 5-1-1 is a subcomponent of c100-3, there is concern that donor samples reacting only with these two antigens (and not with c22-3 or c33c) could be incorrectly classified as positive on the basis of limited reactivity to only one HCV gene product. It is determined that 0.23 to 0.44 percent of HCV enzyme immunoassay-repeatably reactive donor sera demonstrate a pattern of 5-1-1 and c100-3 only on RIBA. Evaluation of six such donor sera using peptide enzyme immunoassays spanning the c100-3 antigen showed highly restricted reactivity to the 5-1-1 N-terminal region of c100-3, in contrast to broad 5-1-1 and c100-3 C-terminal peptide reactivity observed in the majority of donor sera with other positive RIBA patterns. HCV polymerase chain reaction and follow-up serologic evaluations of four of these donors indicated the absence of viremia or evolving seroconversion in all cases. It is concluded that, in the blood donor setting, a pattern of only 5-1-1 and c100-3 reactivity is typically not indicative of HCV infection. To avoid overinterpretation, it is recommended that RIBA grading criteria be revised to require reactivity to two or more HCV-encoded gene products. PMID:7678710

  14. Effects of particle characteristics on magnetic immunoassay in a thin channel.

    PubMed

    Tsai, H Y; Hsieh, Y C; Su, Y M; Chan, J R; Chang, Y C; Fuh, C Bor

    2011-10-15

    The effects of size and porosity of particles on magnetic immunoassay in a thin channel were studied. Experimental parameters were investigated and compared using a model immunoassay complex of carcinoembryonic antigen (CEA)/anti-CEA. The rate constant for the affinity reaction between functional particles increased as the size of magnetic nanoparticles (800-80 nm) decreased. The affinity reaction between functional particles had no significant effect on the sizes of microparticles (1.0-4.4 μm) at commonly used thin channel flow-rates of 0.001-0.025 ml/min. Competitive and sandwich reactions of CEA/anti-CEA were studied for CEA detection. Microparticles of different porosities produced similar linear ranges of detection and limits of detection. The limits of detection for CEA were 0.29 pg/ml and 0.21 pg/ml for competitive and sandwich reactions, respectively. The linear ranges of detection were from 0.49 pg/ml to 4.9 ng/ml for both competitive and sandwich reactions. The detection limits were lower, and the linear ranges were wider than those of literature. There was a 9% difference in CEA detection measurements between competitive and sandwich magnetic immunoassay. The measurements of two magnetic immunoassays differed by less than 13% from the ELISA reference measurements. The running time was less than 30 min. Magnetic immunoassay in a thin channel has great potential for biochemical analysis and immunoassay-related applications. PMID:21788127

  15. Magnetic-bead-based immunoassay using E. coli cells with autodisplayed Z-domains.

    PubMed

    Yoo, Gu; Bong, Ji-Hong; Park, Min; Kang, Min-Jung; Jose, Joachim; Pyun, Jae-Chul

    2013-07-10

    Escherichia coli cells with autodisplayed Z-domains could increase the sensitivity of immunoassays by immobilizing antibodies in a controlled orientation. In the work presented here, E. coli cells with autodisplayed Z-domains were immobilized to magnetic beads for subsequent immunoassay. In comparing conventional immunoassay using the E. coli cells with autodisplayed Z-domains, the magnetic-bead-based immunoassay improved immunoassay efficiency by minimizing the loss of E. coli cells during repeated centrifugation steps during washing. For the immobilization of E. coli cells to magnetic beads, the magnetic beads were modified with poly-l-lysine to bind to negatively charged E. coli cells. During the surface modification process, physical parameters such as the surface charge and size of the magnetic beads were analyzed to confirm the formation of E. coli-magnetic bead complexes. To test the feasibility of the magnetic-bead-based immunoassay, horseradish peroxidase (HRP) was used as a model analyte, and a biomarker for inflammatory diseases, C-reactive protein (CRP), was used for a demonstration of an application in medical diagnosis. PMID:23769312

  16. A rapid lateral flow immunoassay for the detection of fungal alpha-amylase at the workplace.

    PubMed

    Koets, Marjo; Sander, Ingrid; Bogdanovic, Jelena; Doekes, Gert; van Amerongen, Aart

    2006-09-01

    Fungal alpha-amylase is a flour supplement which is added to improve the quality of bakery products. Various studies have shown that exposure to this enzyme is an important risk factor for the development of bakers' allergy and this allergy is reported to be one of the most frequent causes of occupational asthma. A rapid assay was developed to monitor exposure to occupational allergens directly at the workplace. The sensitivity of the developed assay is 0.32 ng amylase mL(-1) in a buffer system with the commercially available alpha-amylase preparation Fungamyl 1600S as the standard. Initial validation tests (n = 33) were performed with airborne and settled dust from an industrial bakery. The new lateral flow immunoassay detected amylase in 22 of the 26 samples regarded as positive in an enzyme immunoassay, and was negative for all seven enzyme immunoassay-negative samples, while the four lateral flow immunoassay-negative/enzyme immunoassay-positive samples all had levels below 2 ng mL(-1). The sensitivity of 2 ng mL(-1) of the amylase lateral flow immunoassay is sufficient for first screening purposes and, therefore, this simple and rapid assay may allow direct on-site demonstration of work-related hazards of bio-allergen exposure. This would be particularly useful in occupational hygiene practice, especially in traditional or small-scale bakeries which lack the technological skills for testing the exposure to respiratory allergens. PMID:16951754

  17. Anti-HCV immunoassays based on a multiepitope antigen and fluorescent lanthanide chelate reporters.

    PubMed

    Salminen, Teppo; Juntunen, Etvi; Khanna, Navin; Pettersson, Kim; Talha, Sheikh M

    2016-02-01

    There is a need for simple to produce immunoassays for hepatitis C virus (HCV) antibody capable of detecting all genotypes worldwide. Current commonly used third generation immunoassays use three to six separate recombinant proteins or synthetic peptides. We have developed and expressed in Escherichia coli a single recombinant antigen incorporating epitopes from different HCV proteins. This multiepitope protein (MEP) was used to develop two types of HCV antibody immunoassays: a traditional antibody immunoassay using a labeled secondary antibody (indirect assay) and a double-antigen assay with the same MEP used as capture binder and labeled binder. The secondary antibody assay was evaluated with 171 serum/plasma samples and double-antigen assay with 148 samples. These samples included an in-house patient sample panel, two panels of samples with different HCV genotypes and a seroconversion panel. The secondary antibody immunoassay showed 95.6% sensitivity and 100% specificity while the double-antigen assay showed 91.4% sensitivity and 100% specificity. Both assays detected samples from all six HCV genotypes. The results showed that combining a low-cost recombinant MEP binder antigen with a high sensitivity fluorescent lanthanide reporter can provide a sensitive and specific immunoassay for HCV serology. The results also showed that the sensitivity of HCV double-antigen assays may suffer from the low avidity immune response of acute infections. PMID:26615808

  18. Cross-reactivity of acetylfentanyl and risperidone with a fentanyl immunoassay.

    PubMed

    Wang, Bei-Tzu; Colby, Jennifer M; Wu, Alan H B; Lynch, Kara L

    2014-01-01

    Fentanyl and its analogs, such as acetylfentanyl, have become a concern for potential abuse. Fentanyl compliance monitoring and urine drug testing are becoming increasingly necessary; however, a limited number of fentanyl immunoassays have been validated for clinical use. The purpose of this study was to validate the use of the DRI® fentanyl immunoassay, determine the potential cross-reactivity of acetylfentanyl and other pharmaceuticals, and investigate acetylfentanyl use in San Francisco. All urine toxicology samples from patients presenting to the emergency department were analyzed using the fentanyl immunoassay for 4 months. Positive samples were analyzed qualitatively using liquid chromatography-high resolution mass spectrometry (LC-HRMS) for fentanyl, fentanyl metabolites, fentanyl analogs and greater than 200 common drugs and metabolites. Subsequently, quantitative analysis was performed using LC-tandem mass spectrometry (LC-MS-MS). Acetylfentanyl, risperidone and 9-hydroxyrisperidone were found to cross-react with the fentanyl immunoassay. No acetylfentanyl was detected in our emergency department patient population. The fentanyl immunoassay demonstrated 100% diagnostic sensitivity in a subset of urines tested; however, the specificity was only 86% due to seven false-positive samples observed. Five of the seven samples were positive for risperidone and 9-hydroxyrisperidone. The DRI® fentanyl immunoassay can be used to screen for fentanyl or acetylfentanyl; however, confirmatory testing should be performed for all samples that screen positive. PMID:25248490

  19. Detection of borna disease virus-reactive antibodies from patients with psychiatric disorders and from horses by electrochemiluminescence immunoassay.

    PubMed

    Yamaguchi, K; Sawada, T; Naraki, T; Igata-Yi, R; Shiraki, H; Horii, Y; Ishii, T; Ikeda, K; Asou, N; Okabe, H; Mochizuki, M; Takahashi, K; Yamada, S; Kubo, K; Yashiki, S; Waltrip, R W; Carbone, K M

    1999-09-01

    The prevalence of Borna disease virus (BDV)-specific antibodies among patients with psychiatric disorders and healthy individuals has varied in several reports using several different serological assay methods. A reliable and specific method for anti-BDV antibodies needs to be developed to clarify the pathological significance of BDV infections in humans. We developed a new electrochemiluminescence immunoassay (ECLIA) for the antibody to BDV that uses two recombinant proteins of BDV, p40 and p24 (full length). Using this ECLIA, we examined 3,476 serum samples from humans with various diseases and 917 sera from blood donors in Japan for the presence of anti-BDV antibodies. By ECLIA, 26 (3.08%) of 845 schizophrenia patients and 9 (3.59%) of 251 patients with mood disorders were seropositive for BDV. Among 323 patients with other psychiatric diseases, 114 with neurological diseases, 75 with chronic fatigue syndrome, 85 human immunodeficiency virus-infected patients, 50 with autoimmune diseases including rheumatoid arthritis and systemic lupus erythematosis and 17 with leprosy, there was no positive case except one case each with alcohol addiction, AIDS, and dementia. Although 19 (1.36%) of 1,393 patients with various ocular diseases, 10 (1.09%) of 917 blood donors, and 3 (4.55%) of 66 multitransfused patients were seropositive for BDV-specific antigen, high levels of seroprevalence in schizophrenia patients and young patients (16 to 59 years old) with mood disorders were statistically significant. The immunoreactivity of seropositive sera could be verified for specificity by blocking with soluble p40 and/or p24 recombinant protein. Anti-p24 antibody was more frequent than p40 antibody in most cases, and in some psychotic patients antibody profiles showed only p40 antibody. Although serum positive for both p40 and p24 antibodies was not found in this study, the p40 ECLIA count in schizophrenia patients was higher than that of blood donors. Furthermore, we examined 90 sera from Japanese feral horses. Antibody profiles of control human samples are similar to that of naturally BDV-infected feral horses. We concluded that BDV infection was associated in some way with psychiatric disorders. PMID:10473520

  20. Analysis of Plasma Cytokine and Chemokine Profiles in Patients with and without Tuberculosis by Liquid Array-Based Multiplexed Immunoassays

    PubMed Central

    Wang, Juanjuan; Zou, Xiaoming; Wen, Qian; Luo, Wei; Liu, Sudong; He, Jianchun; Cai, Shaoxi; Ma, Li

    2016-01-01

    The aim of this study was to establish plasma cytokine/chemokine profiles in patients with 3 different presentations of active tuberculosis (TB), compared to the profiles observed in bacillus Calmette-Guérin (BCG)-vaccinated healthy individuals and patients with other pulmonary diseases (non-TB patients). To this end, plasma samples were collected from 151 TB patients including 68 pulmonary TB (PTB), 43 endobronchial TB, and 40 tuberculosis pleurisy (TP) patients, as well as 107 no-TB cases including 26 non-TB patients and 81 BCG-vaccinated healthy controls. A liquid array-based multiplexed immunoassay was used to screen plasma samples for 20 distinct cytokines and chemokines. Multinomial logistic regression was used to analyze associations between cytokines/chemokines and TB/non-TB patients. Compared to our findings with the no-TB donors, the median plasma levels of the proinflammatory cytokines/chemokines TNF-α, IL-6, IP-10, IFN-γ, and MIP-1β were significantly elevated in TB patients, suggesting their potential use as biomarkers for diagnosing TB patients. Further comparisons with healthy donors showed that only the median TNF-α plasma level was highly produced in the plasma of all 3 types of TB patients. Plasma IL-6 production was higher only in TP patients, while the plasma levels of IP-10, IFN-γ, and MIP-1β were markedly enhanced in both PTB and TP patients. Unexpectedly, among the above cytokines/chemokines, MIP-1β was also highly expressed in non-TB patients, compared with healthy donors. Our results suggested that TNF-α may be an ideal biomarker for diagnosing the 3 forms of TB presentation, while the other factors (IL-6, IP-10, MCP-1, and IFN-γ) can potentially facilitate differential diagnosis for the 3 TB presentation types. Further characterization of immune responses associated with different types of TB diseases will provide a basis for developing novel TB diagnostics. PMID:26881918

  1. Analysis of Plasma Cytokine and Chemokine Profiles in Patients with and without Tuberculosis by Liquid Array-Based Multiplexed Immunoassays.

    PubMed

    Xiong, Wenjing; Dong, Haiping; Wang, Juanjuan; Zou, Xiaoming; Wen, Qian; Luo, Wei; Liu, Sudong; He, Jianchun; Cai, Shaoxi; Ma, Li

    2016-01-01

    The aim of this study was to establish plasma cytokine/chemokine profiles in patients with 3 different presentations of active tuberculosis (TB), compared to the profiles observed in bacillus Calmette-Guérin (BCG)-vaccinated healthy individuals and patients with other pulmonary diseases (non-TB patients). To this end, plasma samples were collected from 151 TB patients including 68 pulmonary TB (PTB), 43 endobronchial TB, and 40 tuberculosis pleurisy (TP) patients, as well as 107 no-TB cases including 26 non-TB patients and 81 BCG-vaccinated healthy controls. A liquid array-based multiplexed immunoassay was used to screen plasma samples for 20 distinct cytokines and chemokines. Multinomial logistic regression was used to analyze associations between cytokines/chemokines and TB/non-TB patients. Compared to our findings with the no-TB donors, the median plasma levels of the proinflammatory cytokines/chemokines TNF-α, IL-6, IP-10, IFN-γ, and MIP-1β were significantly elevated in TB patients, suggesting their potential use as biomarkers for diagnosing TB patients. Further comparisons with healthy donors showed that only the median TNF-α plasma level was highly produced in the plasma of all 3 types of TB patients. Plasma IL-6 production was higher only in TP patients, while the plasma levels of IP-10, IFN-γ, and MIP-1β were markedly enhanced in both PTB and TP patients. Unexpectedly, among the above cytokines/chemokines, MIP-1β was also highly expressed in non-TB patients, compared with healthy donors. Our results suggested that TNF-α may be an ideal biomarker for diagnosing the 3 forms of TB presentation, while the other factors (IL-6, IP-10, MCP-1, and IFN-γ) can potentially facilitate differential diagnosis for the 3 TB presentation types. Further characterization of immune responses associated with different types of TB diseases will provide a basis for developing novel TB diagnostics. PMID:26881918

  2. Comparison of Procleix Ultrio Elite and Procleix Ultrio NAT Assays for Screening of Transfusion Transmitted Infections among Blood Donors in India.

    PubMed

    Chaurasia, Rahul; Rout, Diptiranjan; Zaman, Shamsuz; Chatterjee, Kabita; Pandey, Hem Chandra; Maurya, Abhishek Kumar

    2016-01-01

    Background. Introduction of nucleic acid testing (NAT) has helped in decreasing window period donations, resulting in increased safety of blood supplies. NAT combines the advantages of direct and highly sequence-specific detection of viral genomes. We analysed the performance of newer Procleix Ultrio Elite (PUE) and Procleix Ultrio assay (PUA) for the screening of the viral markers in our donor population. Material and Methods. 10,015 donor samples were screened by routine immunoassays and both versions of NAT. NAT yields detected were subjected to viral load estimation and to other serological markers. Results. A total of 21 NAT yields were detected; three were positive by both NAT systems, whereas 18 samples were reactive by PUE only. NAT yields include 18 HBV and 3 HCV yields, of which 17 HBV yields were occult infections and 1 was window period (WP) infection. All 3 HCV yields were WP infections. No HIV-1/HIV-2 yield was found. Conclusion. Efficient target capture chemistry in the new TMA assay version significantly improved sensitivity. NAT is superior to serological immunoassays for screening of the viral markers; and the efficient target capture system in the newer TMA assay, namely, the PUE system, has significantly improved sensitivity over the earlier versions. PMID:26904124

  3. Comparison of Procleix Ultrio Elite and Procleix Ultrio NAT Assays for Screening of Transfusion Transmitted Infections among Blood Donors in India

    PubMed Central

    Chaurasia, Rahul; Rout, Diptiranjan; Zaman, Shamsuz; Chatterjee, Kabita; Pandey, Hem Chandra; Maurya, Abhishek Kumar

    2016-01-01

    Background. Introduction of nucleic acid testing (NAT) has helped in decreasing window period donations, resulting in increased safety of blood supplies. NAT combines the advantages of direct and highly sequence-specific detection of viral genomes. We analysed the performance of newer Procleix Ultrio Elite (PUE) and Procleix Ultrio assay (PUA) for the screening of the viral markers in our donor population. Material and Methods. 10,015 donor samples were screened by routine immunoassays and both versions of NAT. NAT yields detected were subjected to viral load estimation and to other serological markers. Results. A total of 21 NAT yields were detected; three were positive by both NAT systems, whereas 18 samples were reactive by PUE only. NAT yields include 18 HBV and 3 HCV yields, of which 17 HBV yields were occult infections and 1 was window period (WP) infection. All 3 HCV yields were WP infections. No HIV-1/HIV-2 yield was found. Conclusion. Efficient target capture chemistry in the new TMA assay version significantly improved sensitivity. NAT is superior to serological immunoassays for screening of the viral markers; and the efficient target capture system in the newer TMA assay, namely, the PUE system, has significantly improved sensitivity over the earlier versions. PMID:26904124

  4. The willed body donor interview project: medical student and donor expectations.

    PubMed

    Bohl, Michael; Holman, Alexis; Mueller, Dean A; Gruppen, Larry D; Hildebrandt, Sabine

    2013-01-01

    The Anatomical Donations Program at the University of Michigan Medical School (UMMS) has begun a multiphase project wherein interviews of donors will be recorded and later shown to medical students who participate in the anatomical dissection course. The first phase of this project included surveys of both current UMMS medical students and donors concerning their perceptions of such a program. A five-question survey administered via Qualtrics software was electronically mailed to all current medical students at UMMS, and a survey was mailed to registered and potential donors requesting information from the UMMS on anatomical donations. A total of 224 medical student responses (response rate 33%) and 54 donor responses (response rate 27%) were received. Seventy-four percent of students and 81% of donors reported they would participate in this program if it existed. Students and donors supported the implementation of this program for varying reasons, though many felt strongly they would not want to participate in a donor interview program. These qualitative results support those of previous studies that show a majority of students desire a closer personal relationship with the donor, and these are the first results to be reported on donor perceptions of a donor interview program. Although many students and donors are in favor of instituting this program, others feel strongly that such an experience could be traumatic. The causes of these differing reactions need to be further explored, and the opinions of those who object to this study will be respected by maintaining voluntary participation in future phases of this study. PMID:23109299

  5. Socioeconomic status and ethnicity of deceased donor kidney recipients compared to their donors.

    PubMed

    Adler, J T; Hyder, J A; Elias, N; Nguyen, L L; Markmann, J F; Delmonico, F L; Yeh, H

    2015-04-01

    Public perception and misperceptions of socioeconomic disparities affect the willingness to donate organs. To improve our understanding of the flow of deceased donor kidneys, we analyzed socioeconomic status (SES) and racial/ethnic gradients between donors and recipients. In a retrospective cohort study, traditional demographic and socioeconomic factors, as well as an SES index, were compared in 56,697 deceased kidney donor and recipient pairs transplanted between 2007 and 2012. Kidneys were more likely to be transplanted in recipients of the same racial/ethnic group as the donor (p < 0.001). Kidneys tended to go to recipients of lower SES index (50.5% of the time, p < 0.001), a relationship that remained after adjusting for other available markers of donor organ quality and SES (p < 0.001). Deceased donor kidneys do not appear to be transplanted from donors of lower SES to recipients of higher SES; this information may be useful in counseling potential donors and their families regarding the distribution of their organ gifts. PMID:25758952

  6. Problems in the identification of potential organ donors. Misconceptions and fallacies associated with donor cards.

    PubMed

    Overcast, T D; Evans, R W; Bowen, L E; Hoe, M M; Livak, C L

    A survey of organ procurement programs and district attorneys' offices was undertaken in all 50 states and the District of Columbia to determine to what extent organ donor cards were effective in obtaining organs for purposes of transplantation. Results of the survey revealed that all 50 states and the District of Columbia have adopted some form of the Uniform Anatomical Gift Act (UAGA), but in 47 states, even when a signed donor card is available, surgeons still require family approval for removal of organs despite the fact that the provisions of the UAGA do not require this. In addition, it was found that while 44 states have a provision on their permanent drivers' licenses for organ donation, no state requires drivers to indicate whether they want to donate organs. While there is little information on the number of persons who actually carry donor cards, four states indicated that between 1.7% and 8.5% of their drivers were designated as donors. In Colorado, however, it was reported that 60% of all drivers are designated as donors. Nevertheless, in all states it was determined that few actual donors were carrying donor cards at the time of their death. It must therefore be concluded that while donor cards are an excellent educational medium and certainly facilitate the activities of transplant coordination, they are not an effective means of substantially increasing the supply of organs for transplantation. PMID:6700054

  7. International rare donor panels: a review.

    PubMed

    Nance, S; Scharberg, E A; Thornton, N; Yahalom, V; Sareneva, I; Lomas-Francis, C

    2016-04-01

    International rare blood donor panels or registries are important in the consistent availability of rare blood for patients who need this scarce resource. In countries where it has been possible to commit resources to this effort and often where the need is great, donors have been entered into a registry. The ISBT leadership recognized the importance of this very challenging inventory management activity and created a Working Party to support it. Individual countries support the WHO International Rare Donor Panel by submitting their donors' phenotype or genotype information to be catalogued into the database. It is extremely important that this database be cultivated and grown. The contributing countries keep their list updated and supply the blood product as they can when requested. It is known that some blood types are extremely scarce worldwide and requests for these are particularly difficult to fulfil. Thus, it is important to have a protocol to identify and recruit donors with rare blood types. It is equally or perhaps more important to ensure that the patients who need the rare blood are being managed appropriately in the presence and absence of rare blood products being available. PMID:26689301

  8. Towards a single P donor in Si

    NASA Astrophysics Data System (ADS)

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

    2010-03-01

    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 442 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.

  9. Shallow donors in CdTe

    NASA Astrophysics Data System (ADS)

    Francou, J. M.; Saminadayar, K.; Pautrat, J. L.

    1990-06-01

    Photoluminescence and high-resolution selective excitation of luminescence have been used to study shallow donors in non-intentionally-doped Te-rich or nearly stoichiometric CdTe crystals and their evolution after controlled thermal annealings (specifically under Cd overpressure). It has been shown that there are at least six native donors. For each of these donors, the (1s-->2s) and (1s-->3s) transition energies, the ionization energy, and the exciton localization energy have been determined. The ionization energies range from 13.71 to 14.79 meV and the localization energies obey Haynes's rule. Doping experiments clearly identify the chemical nature of three donors (Ga, In, and Cl), and two other native donors are tentatively ascribed to Al and F. This study clearly indicates that the conversion to n-type behavior induced by the annealing under Cd overpressure does not involve stoichiometric defects like interstitial Cd but is essentially related to a modification of the solubility of the residual contaminants of the ingots.

  10. Donor insemination: eugenic and feminist implications.

    PubMed

    Hanson, F A

    2001-09-01

    One concern regarding developments in genetics is that, when techniques such as genetic engineering become safe and affordable, people will use them for positive eugenics: to "improve" their offspring by enpowering them with exceptional qualities. Another is whether new reproductive technologies are being used to improve the condition of women or as the tools of a patriarchal system that appropriates female functions to itself and exploits women to further its own ends. Donor insemination is relevant to both of these issues. The degree to which people have used donor insemination in the past for positive eugenic purposes may give some insight into the likelihood of developing technologies being so used in the future. Donor insemination provides women with the opportunity to reproduce with only the most remote involvement of a man. To what degree do women take advantage of this to liberate themselves from male dominance? Through questionnaires and interviews, women who have used donor insemination disclosed their criteria for selecting sperm donors. The results are analyzed for the prevalence of positive eugenic criteria in the selection process and women's attitudes toward minimizing the male role in reproduction. PMID:11693033

  11. A Portable Analyzer for Pouch-Actuated, Immunoassay Cassettes

    PubMed Central

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

    2011-01-01

    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

  12. Rapid dioxin screening of milk and water by enzyme immunoassay

    SciTech Connect

    Harrison, R.O.; Carlson, R.E.; Shirkhan, H.

    1995-12-01

    A simple and easy to use enzyme immunoassay (EIA) system has been developed for rapid screening of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378D). This EIA has been adapted to analysis of water and milk using an automated system for extraction of liquid samples. Water analysis can be performed directly following extraction and solvent exchange with no extract clean-up. The same automated system is used for milk extraction and the extract is then cleaned chromatographically using the automated FMS Dioxin-Prep{trademark} System. Sensitivity for 2378D in the EIA is approximately 100 pg per analysis. Thus sensitivity to 10 ppt 2378D (whole weight basis) in milk is possible using only 50 ml or less of sample and sensitivity to 0.1 ppt 2378D in water is possible using 1-2 liters of sample. Total time for sample preparation and analysis is about 3 hours for water and 4.5 hours for milk.

  13. Evaluation of an enzyme immunoassay kit for estrogen receptor measurements.

    PubMed

    Raam, S; Vrabel, D M

    1986-08-01

    Using an enzyme immunoassay (EIA) procedure, we evaluated the ability of the glass beads in the ER-EIA kit of Abbott Laboratories, which were coated with monoclonal anti-estrogen receptor (ER) antibodies, to bind hormone-free and hormone-filled Type I ER in cytosols, buffer washes, and 0.4 mol/L KCI extracts of ultracentrifugal pellets of breast cancer tissue homogenates. The unmodified ER-EIA technique yields higher values than does the dextran-coated charcoal (DCC) method for Type I ER. However, the antibody-coated beads fail to bind hormone-free ER and react with only a certain proportion of ER-[3H]estradiol complexes. The antigen saturation limit of the beads could not be determined because the quantity of antigen bound by the beads was disproportionate and unrelated to the total amount of the antigen available in the cytosols. In buffer extracts of tissue pellets that were ER-negative by the DCC assay, the EIA method detected high quantities of ER. We recommend checking the ability of the monoclonal antibodies to recognize proteins other than Type I ER in the extra-nuclear and nuclear compartments of target cells before using them for immunohistochemical detection of ER. PMID:2426007

  14. Affinity patterns of enzyme tracers for triazine immunoassays

    NASA Astrophysics Data System (ADS)

    Weller, Michael G.; Niessner, Reinhard

    1997-05-01

    Cross-reactivities are one of the most important characteristics of immunoassays. Nevertheless most cross- reactivity studies are only performed with small molecules, which are similar to the target analyte. The complex mechanism of the binding event of an antibody makes it likely that the orientation of the hapten plays a critical role. Therefore cross-reactivities of hapten-derivatives with spacers may be quite different compared to the simple compound, especially when the spacer has been coupled to a large molecule, like a marker enzyme (e.g. peroxidase). We examined the relative affinity patterns of 17 enzyme tracers to 16 monoclonal and polyclonal antibodies for the analysis of triazine herbicides (atrazine, terbuthylazine, etc.). This allows interesting discussions about the structure of the antibody binding site and the comparison of antibodies generated with different immunogens. In addition, some general rules for the selection of immunogen structures could be derived from the data. The figures shown in this paper facilitate to find suitable tracer haptens for one of the tested antibodies and support for instance the optimization of immunosensor regeneration, as tracer affinity is closely correlated to the dissociation rate constant of an antibody-tracer complex.

  15. System and method for a parallel immunoassay system

    DOEpatents

    Stevens, Fred J.

    2002-01-01

    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.

  16. Enzyme immunoassay for determination of gluten in foods: collaborative study.

    PubMed

    Skerritt, J H; Hill, A S

    1991-01-01

    A collaborative study was performed in 15 laboratories to validate a monoclonal antibody-based enzyme immunoassay (EIA) for determination of gluten in foods. The study included 13 samples: maize starch, "gluten-free" baking mixes, wheat flours, cookies, cooked meats, and a soup. Gluten was present in these samples at either zero or 0.02 to 10% by weight, i.e., over almost 3 orders of magnitude. The mean assay values for the foods varied from 88 to 105% of the actual amounts. The assay was quantitative for cereal products and the soup with repeatability (RDS-r, relative standard deviation) and reproducibility (RSD-R) of 16-22% and 24-33%, respectively. The assay was semiquantitative for the processed meat products (RSD-r 14 and 26% and RSD-R 46 and 56%), probably because gluten was unevenly distributed in the small (1 g) samples that were analyzed. The ELISA method produced no false positive results, and false negatives obtained with tannin-containing foods could be avoided by use of a modified sample extractant. None of the collaborators reported problems in following the protocol. The method has been adopted official first action by AOAC for determination of wheat gluten in foods. PMID:2050607

  17. A Microsystem for Magnetic Immunoassay Based on Planar Microcoil Array.

    PubMed

    Zheng, Yushan; Shang, Nan; Haddad, Pierre S; Sawan, Mohamad

    2016-04-01

    This work focuses on the circuit and system implementation of a microsystem platform for magnetic immunoassay, which is a novel type of diagnostic method using magnetic beads as labels. Three main challenges facing this work-design of a high performance sensor, packaging technique and design of integrated circuits are discussed. Planar microcoil array are exploited as sensor of magnetic beads, whereas ultra thin bottom microplate in traditional ELISA is used for the assay. Main circuits blocks include bidirectional current supply circuit, magnetic field sensing circuit and on-chip temperature sensor. Experiments using mouse IgG with different densities were performed on the proposed platform, results show that a minimum density of 100 pg/mL can be detected, which is a comparable sensitivity to conventional optical ELISA, and a quantitative relationship can be acquired in the range from 1 ng/ml to 1 ug/ml, thus this platform is suitable for quantitative analysis in practical health and environment application and has potential for medical diagnostics, food pathogen detection or water analysis. PMID:26173219

  18. Immunoassay for lead ions: analysis of spiked food samples.

    PubMed

    Mandappa, I M; Ranjini, A; Haware, D J; Manonmani, H K

    2014-01-01

    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

  19. High sensitivity, homogeneous particle-based immunoassay for thyrotropin (Multipact).

    PubMed

    Wilkins, T A; Brouwers, G; Mareschal, J C; Cambiaso, C L

    1988-09-01

    We describe the first homogeneous, nonradioactive, high-sensitivity assay for human thyrotropin (TSH). The assay is based on particle immunoassay techniques, wherein 800-nm particles form the basis for the immunochemistry, delivery, and the detection technologies, respectively. Our assay also is the first to involve the use of fragmented monoclonal antibodies (to eliminate serum interferences) covalently coupled to particles without loss of their binding properties. Assays are performed in a semiautomated mode with use of a new modular system (Multipact). Equilibrium is reached in less than 2 h. Precision profile, sensitivity, and clinical studies indicate that the assay is accurate, has good precision at low concentrations, and that detection-limit characteristics compare well with those of a leading commercial high-sensitivity immunoradiometric assay (IRMA) for TSH. Dilution characteristics were satisfactory down to the assay's detection limit for a range of clinical samples. Correlation studies vs a reference IRMA method yielded the regression equation, present method = 0.976 (IRMA) + 0.002 milli-int. unit/L (r = 0.98), for 223 samples with TSH concentrations in the range 0 to 30 milli-int. units/L. For 40 samples with TSH less than or equal to 1.0 milli-int. unit/L it was: present method = 0.94 (IRMA) + 0.005 milli-int. unit/L (r = 0.96). PMID:3416423

  20. The microassay on a card: A rugged, portable immunoassay

    NASA Technical Reports Server (NTRS)

    Kidwell, David

    1991-01-01

    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.

  1. Bioluminescent enzyme immunoassay for the detection of norovirus capsid antigen.

    PubMed

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

    2012-12-01

    An ultrasensitive and fully automated bioluminescent enzyme immunoassay (BLEIA) was developed for the detection of norovirus (NV) capsid antigen. In the evaluation tests with recombinant virus-like particles, the BLEIA demonstrated broad reactivity against several NV genotypes (genotypes 1, 3, 4, 7, 8, and 12 in genogroup I [GI] and genotypes 1, 2, 3, 4, 5, 6, 12, and 13 in GII), a wide dose-response range from 0.25 pg/ml to 10,000 pg/ml, and good reproducibility with low coefficients of variation (CVs) (within-run CVs of <2.8%, between-day CVs of <3.7%). In the evaluation tests with NV-positive fecal samples, a good correlation (y = 0.66x - 3.21, r = 0.84) between the BLEIA and real-time quantitative reverse transcription-PCR was obtained. Furthermore, in the dilution test with NV specimens, the analytical sensitivity of NV was estimated to be 10(5) to 10(6) copies/g of fecal sample, indicating that the analytical sensitivity of the BLEIA is comparable to that of commercially available molecular methods. All assay steps are fully automated, the turnaround time is 46 min, and the throughput of the assay is 120 tests/h. These results indicate that the BLEIA is potentially useful for the rapid diagnosis of NV in epidemic and sporadic gastroenteritis. PMID:23081816

  2. Surface plasmon resonance-based immunoassay for human fetuin A.

    PubMed

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

    2014-05-01

    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

  3. Cavity-Enhanced Immunoassay Measurements in Microtiter Plates Using BBCEAS.

    PubMed

    Bajuszova, Zuzana; Ali, Zulfiqur; Scott, Simon; Seetohul, L Nitin; Islam, Meez

    2016-05-17

    We report on the first detailed use of broadband cavity enhanced absorption spectroscopy (BBCEAS) as a detection system for immunoassay. A vertical R ≥ 0.99 optical cavity was integrated with a motorized XY stage, which functioned as a receptacle for 96-well microtiter plates. The custom-built cavity enhanced microplate reader was used to make measurements on a commercially available osteocalcin sandwich ELISA kit. A 30-fold increase in path length was obtained with a minimum detectable change in the absorption coefficient, αmin(t), of 5.3 × 10(-5) cm(-1) Hz(-1/2). This corresponded to a 39-fold increase in the sensitivity of measurement when directly compared to measurements in a conventional microplate reader. Separate measurements of a standard STREP-HRP colorimetric reaction in microtiter plates of differing optical quality produced an increase in sensitivity of up to 115-fold compared to a conventional microplate reader. The sensitivity of the developed setup compared favorably with previous liquid-phase cavity enhanced studies and approaches the sensitivity of typical fluorometric ELISAs. It could benefit any biochemical test which uses single pass absorption as a detection method, through either the label free detection of biologically important molecules at lower concentrations or the reduction in the amount of expensive biochemicals needed for a particular test, leading to cheaper tests. PMID:27089516

  4. Sensitive, Fast, and Specific Immunoassays for Methyltestosterone Detection

    PubMed Central

    Kong, Na; Song, Shanshan; Peng, Juan; Liu, Liqiang; Kuang, Hua; Xu, Chuanlai

    2015-01-01

    An indirect competitive enzyme-linked immunosorbent assay (icELISA) and an immunochromatographic strip assay using a highly specific monoclonal antibody, were developed to detect methyltestosterone (MT) residues in animal feed. The optimized icELISA had a half-inhibition concentration value of 0.26 ng/mL and a limit of detection value of 0.045 ng/mL. There was no cross-reactivity with eight analogues, revealing high specificity for MT. Based on icELISA results, the recovery rate of MT in animal feed was 82.4%–100.6%. The results were in accordance with those obtained by gas chromatography-mass spectrometry. The developed immunochromatographic strip assay, as the first report for MT detection, had a visual cut-off value of 1 ng/mL in PBS, 2.5 ng/g in fish feed, and 2.5 ng/g in pig feed. Therefore, these immunoassays are useful and fast tools for MT residue detection in animal feed. PMID:25938198

  5. Designing novel nano-immunoassays: antibody orientation versus sensitivity

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

    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.

  6. Sensitivity and Specificity of Histoplasma Antigen Detection by Enzyme Immunoassay.

    PubMed

    Cunningham, Lauren; Cook, Audrey; Hanzlicek, Andrew; Harkin, Kenneth; Wheat, Joseph; Goad, Carla; Kirsch, Emily

    2015-01-01

    The objective of this study was to evaluate the sensitivity and specificity of an antigen enzyme immunoassay (EIA) on urine samples for the diagnosis of histoplasmosis in dogs. This retrospective medical records review included canine cases with urine samples submitted for Histoplasma EIA antigen assay between 2007 and 2011 from three veterinary institutions. Cases for which urine samples were submitted for Histoplasma antigen testing were reviewed and compared to the gold standard of finding Histoplasma organisms or an alternative diagnosis on cytology or histopathology. Sensitivity, specificity, negative predictive value, positive predictive value, and the kappa coefficient and associated confidence interval were calculated for the EIA-based Histoplasma antigen assay. Sixty cases met the inclusion criteria. Seventeen cases were considered true positives based on identification of the organism, and 41 cases were considered true negatives with an alternative definitive diagnosis. Two cases were considered false negatives, and there were no false positives. Sensitivity was 89.47% and the negative predictive value was 95.35%. Specificity and the positive predictive value were both 100%. The kappa coefficient was 0.9207 (95% confidence interval, 0.8131-1). The Histoplasma antigen EIA test demonstrated high specificity and sensitivity for the diagnosis of histoplasmosis in dogs. PMID:26355580

  7. Backscattering particle immunoassays in wire-guide droplet manipulations.

    PubMed

    Yoon, Jeong-Yeol; You, David J

    2008-01-01

    A simpler way for manipulating droplets on a flat surface was demonstrated, eliminating the complications in the existing methods of open-surface digital microfluidics. Programmed and motorized movements of 10 muL droplets were demonstrated using stepper motors and microcontrollers, including merging, complicated movement along the programmed path, and rapid mixing. Latex immunoagglutination assays for mouse immunoglobulin G, bovine viral diarrhea virus and Escherichia coli were demonstrated by merging two droplets on a superhydrophobic surface (contact angle = 155 +/- 2 degrees ) and using subsequent back light scattering detection, with detection limits of 50 pg mL-1, 2.5 TCID50 mL-1 and 85 CFU mL-1, respectively, all significantly lower than the other immunoassay demonstrations in conventional microfluidics (~1 ng mL-1 for proteins, ~100 TCID50 mL-1 for viruses and ~100 CFU mL-1 for bacteria). Advantages of this system over conventional microfluidics or microwell plate assays include: (1) minimized biofouling and repeated use (>100 times) of a platform; (2) possibility of nanoliter droplet manipulation; (3) reprogrammability with a computer or a game pad interface. PMID:19014703

  8. Enzyme immunoassay of thyroxin with a centrifugal analyzer

    SciTech Connect

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

    1982-01-01

    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.

  9. Specific immunoassays for placental alkaline phosphatase as a tumor marker.

    PubMed

    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

    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

  10. Diagnosis of tuberculosis by a visually detectable immunoassay for lipoarabinomannan.

    PubMed

    Chan, E D; Reves, R; Belisle, J T; Brennan, P J; Hahn, W E

    2000-05-01

    Recovery of tubercle bacilli from sputum, tissue, or body fluid is the standard for the diagnosis of tuberculosis (TB) although this process is technically demanding and relatively insensitive. We have developed a simplified, visually detectable, colloidal gold-based serological assay to qualitatively detect IgG directed against the mycobacterial cell wall component lipoarabinomannan (LAM). The objective of this investigation is to determine the accuracy of this assay in patients with active pulmonary TB and in control patients with or without latent infection. In patients with active TB, the sensitivity of anti-LAM IgG was 85 to 93%. In five patients with active TB who were smear-negative, all tested positive for anti-LAM IgG. The specificity of the test depended on the presence of tuberculous infection. In U.S. citizens comprised of young healthy adults and rheumatology patients, the specificity was 100%. In an at-risk population for tuberculous infection who were either tuberculin skin test-negative or positive, the specificity was 89%. The negative and positive predictive values of the test were 98% and 52%, respectively. We conclude that anti-LAM IgG immunoassay is relatively sensitive and specific for active TB and thus, a potentially useful screening test for active TB. PMID:10806179

  11. Microfluidic immunoassays as rapid saliva-based clinical diagnostics

    PubMed Central

    Herr, Amy E.; Hatch, Anson V.; Throckmorton, Daniel J.; Tran, Huu M.; Brennan, James S.; Giannobile, William V.; Singh, Anup K.

    2007-01-01

    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 μl 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. PMID:17374724

  12. Analysis of cooked-food mutagens by HPLC/immunoassay

    SciTech Connect

    Watkins, B.E.; Vanderlaan, M.; Felton, J.S.

    1988-10-10

    Recognizing that an immunoassay for these aminoimidazoazaarenes (AIAs) could be an analytical method with higher sample throughput and would be less costly, we developed a set of monoclonal antibodies that selectively bind to each of the AIAs. We selected PhIP (6-phenyl-2-amino-1-methylimidazo(4,5-b)pyridine) for the initial assay development because it is the AIA that is most abundant by mass in cooked meat and it is the most genotoxic AIA in mammalian-cell short-term bioassays. It is, however, the least active AIA in the Ames Salmonella mutagenesis assay. We have recently developed a set of four monoclonals that bind to the PhIP. These antibodies were produced by standard methods and were derived from the immunogen described previously. The binding specificity of each of these antibodies has been well characterized. The most specific antibody, called PhIP-1, will bind PhIP with a 50% inhibition point (I/sub 50/) of 30 ng, and it will not bind to any of the other AIA mutagens, nor to any of a number of synthetically produced derivatives of PhIP, such as Iso-PhIP (6-phenyl-2-amino-3-methylimidazo(4,5-b)pyridine). PhIP-1 does bind with 2-deamino-PhIP and 2-deamino-2-nitro-PhIP with an I/sub 50/ of 13 and 16 ng, respectively. 9 refs., 3 figs.

  13. Quantitative analysis of plasma interleiukin-6 by immunoassay on microchip

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    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 μm width and 100 μm 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.

  14. Haptens and monoclonal antibodies for immunoassay of imidazolinone herbicides.

    PubMed

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

    2002-06-01

    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

  15. The theoretically ideal donor site dressing.

    PubMed

    Birdsell, D C; Hein, K S; Lindsay, R L

    1979-06-01

    Many of the choices for managing split-thickness skin graft donor sites are satisfactory, but none is ideal. Epidermal regeneration in a donor site is readily available for clinical study. We have reviewed experimental studies of epidermal regeneration and applied those results to the clinical study of a new donor site dressing. This dressing is a vapor-permeable, transparent, polyurethane film with a polyvinyl ether adhesive. Used on 100 patients, it was found to be safe and effective in allowing rapid and painless healing. Although the dressing is occlusive and theoretically could promote infection in a contaminated wound, no infections were encountered. Comparison was made with 15 patients managed by other methods. No marked difference in healing time was noted clinically. The striking advantage of the new dressing was painless healing. PMID:396845

  16. Transmission of donor melanoma by organ transplantation.

    PubMed

    Strauss, Dirk C; Thomas, J Meirion

    2010-08-01

    Transplant-related malignancies are a major contributor to morbidity and mortality in the organ-recipient population, and most often develop de novo in the immunosuppressed recipient or as recurrent malignancy after transplantation. The least common scenario, and a rare event, is a recipient malignancy derived from the donor organ. Melanoma is one of the most often reported and lethal donor-derived malignancies with a high transmission rate. Donor transmission of melanoma might be related to the biology of melanoma, with regard to tumour dormancy, late recurrence, circulating tumour cells, and the destiny of some micrometastases. Melanoma-cell dormancy explains the late recurrence that can occur after the initial treatment of melanoma, and may be relevant to our understanding and management of some melanoma micrometastasis in the sentinel node. The high incidence of circulating tumour cells in early melanoma should be considered in the context of the transmission of melanoma by apparent disease-free organ donors following removal of a primary melanoma up to 32 years before. This scenario suggests that melanoma cells can remain dormant at distant sites for decades (and possibly forever) in immunocompetent patients, only to reactivate after transplantation into an immunosuppressed recipient. Potential organ donors should be carefully screened for a history of melanoma, and excluded. The current recommendation for treatment of donor-related melanoma includes withdrawal of immunosuppression, graft rejection, and explantation of the allograft after rejection has been established. In non-renal transplant patients with life-sustaining organs, withdrawal of immunosuppression and graft rejection is not feasible, and reduction of immunosuppression or urgent retransplantation are the only possible salvage strategies. The transmission of malignancy by organ donation could be considered "nature's own experiment", but raises questions that our current understanding of the biology of melanoma cannot answer. PMID:20451456

  17. Liver regeneration after living donor transplantation: adult-to-adult living donor liver transplantation cohort study.

    PubMed

    Olthoff, Kim M; Emond, Jean C; Shearon, Tempie H; Everson, Greg; Baker, Talia B; Fisher, Robert A; Freise, Chris E; Gillespie, Brenda W; Everhart, James E

    2015-01-01

    Adult-to-adult living donors and recipients were studied to characterize patterns of liver growth and identify associated factors in a multicenter study. Three hundred and fifty donors and 353 recipients in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL) receiving transplants between March 2003 and February 2010 were included. Potential predictors of 3-month liver volume included total and standard liver volumes (TLV and SLV), Model for End-Stage Liver Disease (MELD) score (in recipients), the remnant and graft size, remnant-to-donor and graft-to-recipient weight ratios (RDWR and GRWR), remnant/TLV, and graft/SLV. Among donors, 3-month absolute growth was 676 ± 251 g (mean ± SD), and percentage reconstitution was 80% ± 13%. Among recipients, GRWR was 1.3% ± 0.4% (8 < 0.8%). Graft weight was 60% ± 13% of SLV. Three-month absolute growth was 549 ± 267 g, and percentage reconstitution was 93% ± 18%. Predictors of greater 3-month liver volume included larger patient size (donors and recipients), larger graft volume (recipients), and larger TLV (donors). Donors with the smallest remnant/TLV ratios had larger than expected growth but also had higher postoperative bilirubin and international normalized ratio at 7 and 30 days. In a combined donor-recipient analysis, donors had smaller 3-month liver volumes than recipients adjusted for patient size, remnant or graft volume, and TLV or SLV (P = 0.004). Recipient graft failure in the first 90 days was predicted by poor graft function at day 7 (HR = 4.50, P = 0.001) but not by GRWR or graft fraction (P > 0.90 for each). Both donors and recipients had rapid yet incomplete restoration of tissue mass in the first 3 months, and this confirmed previous reports. Recipients achieved a greater percentage of expected total volume. Patient size and recipient graft volume significantly influenced 3-month volumes. Importantly, donor liver volume is a critical predictor of the rate of regeneration, and donor remnant fraction affects postresection function. Liver Transpl 21:79-88, 2015. © 2014 AASLD. PMID:25065488

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

    PubMed Central

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

    2013-01-01

    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. PMID:23611727

  19. Making benzotrithiophene a stronger electron donor.

    PubMed

    Guo, Xin; Wang, Suhao; Enkelmann, Volker; Baumgarten, Martin; Müllen, Klaus

    2011-11-18

    A new member of the benzotrithiophene family, benzo[2,1-b:-3,4-b':5,6-c″]trithiophene (3a), and its alkyl substituted derivatives (3b-e) were synthesized and characterized. Their photophyscial, electrochemical, crystallographic, and self-assembly properties were described. Thin film structures varied widely with the exact nature of the alkyl substitution pattern, with decreasing self-assembly propensity with increasing alkyl chain length. The high HOMO levels and the coplanarity of these molecules show their potential as organic semiconductors and as donor components in donor-acceptor copolymers. PMID:22032236

  20. A computerized national Blood Donor Deferral Register.

    PubMed

    Ellis, F R; Friedman, L I; Wirak, B F; Hellinger, M J; Malin, W S; Greenwalt, T J

    1975-05-19

    With blood given exclusively by volunteer donors, the American National Red Cross (ANRC) Blood Program aims to supply patients needing transfusion with blood products of the highest quality. The use of blood from volunteers, with its established greater safety, combined with laboratory testing to detect carriers of hepatitis B surface antigen (HB-SAg) and modern computer technology, creates an effective system to reduce the risk of post-transfusion hepatitis. The ANRC has devised a national Donor Deferral System, which is designed to minimize the transmission of hepatitis by blood and blood products. PMID:1173170

  1. Living Donor Lung Transplantation for Pleuroparenchymal Fibroelastosis.

    PubMed

    Hata, Atsushi; Nakajima, Takahiro; Yoshida, Shigetoshi; Kinoshita, Taku; Terada, Jiro; Tatsumi, Koichiro; Matsumiya, Goro; Date, Hiroshi; Yoshino, Ichiro

    2016-05-01

    We report the first patient with pleuroparenchymal fibroelastosis (PPFE) to undergo living donor bilateral lobar lung transplantation. The patient was diagnosed with secondary PPFE as a late complication of chemotherapy that included high-dose cyclophosphamide for mature B-cell lymphocytic leukemia. Although the patient maintained complete remission, dry cough and back pain appeared 8 years after the chemotherapy. He had repeated bilateral pneumothoraces, and his respiratory condition gradually deteriorated because of progressive pleural thickening and parenchymal fibrosis. He underwent living-donor bilateral lobar lung transplantation with an inverse transplant on the left side. PMID:27106430

  2. Prevalence of p24 antigen among a cohort of HIV antibody negative blood donors in Sokoto, North Western Nigeria - the question of safety of blood transfusion in Nigeria

    PubMed Central

    Osaro, Erhabor; Mohammed, Ndakotsu; Zama, Isaac; Yakubu, Abdulrahaman; Dorcas, Ikhuenbor; Festus, Aghedo; Kwaifa, Ibrahim; Sani, Ibrahim

    2014-01-01

    Introduction Blood transfusions remain a substantial source of HIV in SSA particularly among children and pregnant women. Aims and objectives: This aim of this retrospective study was to investigate the prevalence of p24 antigen among HIV antibody seronegative blood donors in Sokoto, North West Nigeria. Methods A total of 15,061 HIV antibody negative blood donors with mean age and age range (29.2 ± 8.18 and 18-50 years) were screened for p24 antigen between January 2010 to July 2013 using the Diapro Diagnostic immunoassay kit for P24 antigen (King Hawk Pharmaceuticals Beijing China). Results The overall prevalence of p24 antigen among the HIV antibody negative donors sample was 5.84%. The yearly prevalence was 9.79, 8.12, 2.7 and 2.84% respectively in 2010, 2011, 2012 and 2013. Of the total number of blood donor tested, 14,968 (99.38%) were males while 93 (0.62%) were females. The prevalence of P24 antigen was significantly higher among male blood donors 873 (5.8%) compared to females 7(0.05%), (p= 0.001). P24 positivity was significantly higher among blood group O blood donors compared to A, B and AB donors (494 (3.29%) compared to 184 (1.89%), 196 (1.30%) and 6 (0.04%)) respectively, p = 0.001). The prevalence of P24 antigen was significantly higher among Rhesus positive blood donors compared to Rhesus negative (807 (5.36%) versus 73 (0.48%), p =0.001). Conclusion Blood transfusion in Nigeria is associated with increased risk of HIV transmission. There is the urgent need to optimize the screening of blood donors in Nigeria by the inclusion of p24 antigen testing into the blood donor screening menu. The Nigerian government urgently need to adopt the WHO blood safety strategies to reduce the risk of transmission of HIV through blood transfusion. PMID:25419301

  3. Donor Hemodynamics as a Predictor of Outcomes After Kidney Transplantation From Donors After Cardiac Death.

    PubMed

    Allen, M B; Billig, E; Reese, P P; Shults, J; Hasz, R; West, S; Abt, P L

    2016-01-01

    Donation after cardiac death is an important source of transplantable organs, but evidence suggests donor warm ischemia contributes to inferior outcomes. Attempts to predict recipient outcome using donor hemodynamic measurements have not yielded statistically significant results. We evaluated novel measures of donor hemodynamics as predictors of delayed graft function and graft failure in a cohort of 1050 kidneys from 566 donors. Hemodynamics were described using regression line slopes, areas under the curve, and time beyond thresholds for systolic blood pressure, oxygen saturation, and shock index (heart rate divided by systolic blood pressure). A logistic generalized estimation equation model showed that area under the curve for systolic blood pressure was predictive of delayed graft function (above median: odds ratio 1.42, 95% confidence interval [CI] 1.06-1.90). Multivariable Cox regression demonstrated that slope of oxygen saturation during the first 10 minutes after extubation was associated with graft failure (below median: hazard ratio 1.30, 95% CI 1.03-1.64), with 5-year graft survival of 70.0% (95%CI 64.5%-74.8%) for donors above the median versus 61.4% (95%CI 55.5%-66.7%) for those below the median. Among older donors, increased shock index slope was associated with increased hazard of graft failure. Validation of these findings is necessary to determine the utility of characterizing donor warm ischemia to predict recipient outcome. PMID:26361242

  4. Related hematopoietic cell donor care: is there a role for unrelated donor registries?

    PubMed

    Anthias, C; van Walraven, S M; Sørensen, B S; de Faveri, G N; Fechter, M; Cornish, J; Bacigalupo, A; Müller, C; Boo, M; Shaw, B E

    2015-05-01

    In almost half of allogeneic hematopoietic progenitor cell (HPC) transplants, a related donor (RD) is used, yet a lack of standardized guidelines means that their care is heterogeneous. Changes to regulatory standards aim to improve uniformity, but adherence to these regulations can prove logistically difficult for the transplant centers (TCs) managing RDs. Discussion has ensued around possible alternative models of related donor care and a session at the European Society for Blood and Marrow Transplantation (EBMT) annual meeting in 2013 debated the question of whether a role exists for unrelated donor registries in the management of 'related' donors. In this overview, we discuss the issues raised at this debate and the pros and cons of donor registry involvement in various aspects of RD management. By examining existing models of related donor care that have been adopted by members of the World Marrow Donor Association (WMDA), we look for ways to enhance and homogenize RD care, while also enabling transplant centers to meet standards required for mandatory accreditation. PMID:25730182

  5. Disclosing recipient information to potential living donors: preferences of donors and recipients, before and after surgery.

    PubMed

    Rodrigue, J R; Ladin, K; Pavlakis, M; Mandelbrot, D A

    2011-06-01

    Consensus guidelines, while recommending that potential living donors should be given information that could impact their donation decision, are nonspecific about the types of information that should be disclosed. We surveyed potential (n = 36) and past (n = 45) living donors and transplant candidates (n = 45) and recipients (n = 45) about their preferences for sharing or knowing specific information about the recipient, how this information would impact decision-making, and who should be responsible for disclosing information. Potential donors were less likely than all others to feel that recipient information should be disclosed to potential donors. Donors and recipients felt most strongly about disclosing if the recipient lost a previously transplanted kidney due to medication nonadherence as well as the likelihood of 1- and 5-year graft survival. Most donors would be less likely to pursue donation if the recipient lost a previously transplanted kidney due to medication nonadherence or generally had problems with taking medications as prescribed. Transplant programs should consider how to best balance the potential donor's right to receive information that could reasonably be expected to affect their decision-making process with the recipient's right to privacy and confidentiality. PMID:21645257

  6. ALTERNATIVE DONORS EXTEND TRANSPLANTATION FOR PATIENTS WITH LYMPHOMA WHO LACK AN HLA MATCHED DONOR

    PubMed Central

    Bachanova, Veronika; Burns, Linda J.; Wang, Tao; Carreras, Jeanette; Gale, Robert Peter; Wiernik, Peter H.; Ballen, Karen K.; Wirk, Baldeep; Munker, Reinhold; Rizzieri, David A.; Chen, Yi-Bin; Gibson, John; Akpek, Görgün; Costa, Luciano J.; Kamble, Rammurti T.; Aljurf, Mahmoud D.; Hsu, Jack W.; Cairo, Mitchell S.; Schouten, Harry C.; Bacher, Ulrike; Savani, Bipin N.; Wingard, John R.; Lazarus, Hillard M.; Laport, Ginna G.; Montoto, Silvia; Maloney, David G.; Smith, Sonali M.; Brunstein, Claudio; Saber, Wael

    2015-01-01

    Alternative donor transplantation is increasingly used for high risk lymphoma patients. We analyzed 1593 transplant recipients (2000 to 2010) and compared transplant outcomes in recipients of 8/8 allele human leukocyte antigen (HLA)-A, -B, -C, and DRB1 matched unrelated donors (MUD; n=1176), 7/8 allele HLA-matched unrelated donors (MMUD; n=275) and umbilical cord blood donors (1 or 2 units UCB; n=142). Adjusted 3-year non-relapse mortality of MMUD (44%) was higher as compared to MUD (35%; p=0.004), but similar to UCB recipients (37%; p=0.19), although UCB had lower rates of neutrophil and platelet recovery compared to unrelated donor groups. With a median follow-up of 55 months, 3-year adjusted cumulative incidence of relapse was lower after MMUD compared with MUD (25% vs 33%, p=0.003) but similar between UCB and MUD (30% vs 33%; p=0.48). In multivariate analysis UCB recipients had lower risks of acute and chronic graft versus host disease compared with adult donor groups (UCB vs MUD: HR=0.68, p=0.05; HR=0.35; p<0.001). Adjusted 3-year overall survival was comparable (43% MUD, 37% MMUD and 41% UCB). Data highlight that patients with lymphoma have acceptable survival after alternative donor transplantation. MMUD and UCB can expand the curative potential of allotransplant to patients who lack suitable HLA-matched sibling or MUD. PMID:25402415

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

    PubMed Central

    2014-01-01

    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 11β-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. PMID:25071417

  8. Seroepidemiology of Toxoplasma gondii Infection among Healthy Blood Donors in Taiwan

    PubMed Central

    Chiang, Ting-Yi; Hsieh, Hwei-Ho; Kuo, Ming-Chu; Chiu, Kai-Tse; Lin, Wei-Chen; Fan, Chia-Kwung; Fang, Chi-Tai; Ji, Dar-Der

    2012-01-01

    Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3%) tested positive for anti-Toxoplasma IgG, while 5 (0.28%) tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3–6.5), raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5–19.1), having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2–3.2), a lower education level (adjusted OR = 1.6; 95% CI: 1.1–2.3), and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6–3.9) were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan. PMID:23133557

  9. Decision Making in Kidney Paired Donation Programs with Altruistic Donors*

    PubMed Central

    Li, Yijiang; Song, Peter X.-K.; Leichtman, Alan B.; Rees, Michael A.; Kalbfleisch, John D.

    2014-01-01

    In recent years, kidney paired donation (KPD) has been extended to include living non-directed or altruistic donors, in which an altruistic donor donates to the candidate of an incompatible donor-candidate pair with the understanding that the donor in that pair will further donate to the candidate of a second pair, and so on; such a process continues and thus forms an altruistic donor-initiated chain. In this paper, we propose a novel strategy to sequentially allocate the altruistic donor (or bridge donor) so as to maximize the expected utility; analogous to the way a computer plays chess, the idea is to evaluate different allocations for each altruistic donor (or bridge donor) by looking several moves ahead in a derived look-ahead search tree. Simulation studies are provided to illustrate and evaluate our proposed method. PMID:25309603

  10. Autoantibody testing for connective tissue diseases. Comparison of immunodiffusion, immunoblot, and enzyme immunoassay.

    PubMed

    Bridges, A J; Lorden, T E; Havighurst, T C

    1997-10-01

    We evaluated 500 consecutive patient serum samples for the presence of six autoantibodies by three antibody detection methods: immunodiffusion, immunoblot, and enzyme immunoassay. Clinical data were reviewed for each patient with positive antibody test results. Serum samples from 60 patients revealed antibodies to Sm, ribonucleoprotein (RNP), SSA/Ro, SSB/La, Scl-70, or Jo-1. There were 7 false-positive test results (1%). All three methods detected autoantibodies in 36 (68%) of 53 patients with connective tissue disease. Immunoblot was the most sensitive method to detect autoantibodies (92%). Enzyme immunoassay and immunodiffusion were less sensitive (81% and 74%, respectively). Antiribonucleoprotein and anti-SSB/La antibodies were more often detected by immunoblotting, whereas anti-SSA/Ro antibodies were more often detected by enzyme immunoassay. Newer antibody detection methods (immunoblot and enzyme immunoassay) are less time consuming than immunodiffusion and show good interassay sensitivity without loss of specificity. A combination of immunoblot and enzyme immunoassay yielded excellent assay sensitivity (100%) and specificity (99%) for detection of autoantibodies. PMID:9322593

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

    PubMed Central

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

    2010-01-01

    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. PMID:19333148

  12. Microfluidic immunoassay with plug-in liquid crystal for optical detection of antibody.

    PubMed

    Zhu, Qingdi; Yang, Kun-Lin

    2015-01-01

    Recent advance in liquid crystal (LqC) based immunoassays enables label-free detection of antibody, but manual preparation of LqC cells and injection of LqC are required. In this work, we developed a new format of LqC-based immunoassay which is hosted in a microfluidic device. In this format, the orientations of LqC are strongly influenced by four channel walls surrounding the LqC. When the aspect ratio (depth/width) of the channel is smaller than 0.38, LqC orients homeotropically inside the microchannel and appears dark. After antigens bind to immobilized antibodies on the channel walls, a shift of the LqC appearance from dark to bright (due to the disruption of LqC orientation) can be visualized directly. To streamline the immunoassay process, a tubing cartridge loaded with a sample solution, washing buffers and a plug of LqC is connected to the microfluidic device. By using pressure-driven flow, the cartridge allows antigen/antibody binding, washing and optical detection to be accomplished in a sequential order. We demonstrate that this microfluidic immunoassay is able to detect anti-rabbit IgG with a naked-eye detection limit down to 1 μg mL(-1). This new format of immunoassay provides a simple and robust approach to perform LqC-based label-free immunodetection in microfluidic devices. PMID:25467520

  13. Label-free impedimetric immunoassay for trace levels of polychlorinated biphenyls in insulating oil.

    PubMed

    Date, Yasumoto; Aota, Arata; Sasaki, Kazuhiro; Namiki, Yukie; Matsumoto, Norio; Watanabe, Yoshitomo; Ohmura, Naoya; Matsue, Tomokazu

    2014-03-18

    A rapid, ultrasensitive, and practical label-free impedimetric immunoassay for measuring trace levels of total polychlorinated biphenyls (PCBs) in insulating oil was developed. First, we developed a novel monoclonal antibody (RU6F9) for PCBs by using a designed immunogen and characterized its binding affinity for a commercial mixtures of PCBs and its main congeners. A micro comblike gold electrode was fabricated, and the antibody was covalently immobilized on the electrode through a self-assembled monolayer formed by dithiobis-N-succinimidyl propionate. The antigen-binding event on the surface of the functionalized electrode was determined as the change in charge transfer resistance by using electrochemical impedance spectroscopy. The resulting impedimetric immunoassay in aqueous solution achieved a wide determination range (0.01-10 μg/L) and a low detection limit (LOD) of 0.001 μg/L, which was 100-fold more sensitive than a conventional flow-based immunoassay for PCBs. By combining the impedimetric immunoassay with a cleanup procedure for insulating oil utilizing a multilayer cleanup column followed by DMSO partitioning, an LOD of 0.052 mg/kg-oil was achieved, which satisfied the Japanese regulation criterion of 0.5 mg/kg-oil. Finally, the immunoassay was employed to determine total PCB levels in actual used insulating oils (n = 33) sampled from a used transformer containing trace levels of PCBs, and the results agreed well with the Japanese official method (HRGC/HRMS). PMID:24528234

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

    PubMed

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

    2013-04-01

    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

  15. Hydrogen-donor coal liquefaction process

    DOEpatents

    Wilson, Jr., Edward L.; Mitchell, Willard N.

    1980-01-01

    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.

  16. Alternative donors: cord blood for adults.

    PubMed

    Ruggeri, Annalisa

    2016-04-01

    Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for patients with hematological diseases. The probability of finding a human leukocyte antigen (HLA)- identical donor among family members is around 25% and 30% that of having a full matched unrelated donor in the registry. Patients in need may also benefit of a HLA-mismatched HSCT either from an haploidentical donors or from umbilical cord blood (UCB). Much has been learned about UCB transplant (UCBT) since the first human UCBT was performed back in 1988. Cord blood banks have been established worldwide for the collection, cryopreservation, and distribution of UCB for HSCT. Today, a global network of cord blood banks and transplant centers has been established with a large common inventory of more than 650,000 UCB units available, allowing for more than 40,000 UCBT worldwide in children and adults with severe hematological diseases. Several studies have been published on UCBT, assessing risk factors such as cell dose and HLA mismatch. Outcomes of several retrospective comparative studies showed similar results using other stem cell sources both in pediatric and adult setting. New strategies are ongoing to facilitate engraftment and reduce transplant-related mortality. In this issue, we review the current results of UCBT in adults with hematological malignancies and the clinical studies comparing UCBT with other transplant strategies. We provide guidelines for donor algorithm selection in UCBT setting. PMID:27000728

  17. Electron shuttling in phosphorus donor qubit systems

    NASA Astrophysics Data System (ADS)

    Jacobson, N. Tobias; Gamble, John King; Nielsen, Erik; Muller, Richard P.; Witzel, Wayne M.; Montano, Ines; Carroll, Malcolm S.

    2014-03-01

    Phosphorus donors in silicon are a promising qubit architecture, due in large part to their long nuclear coherence times and the recent development of atomically precise fabrication methods. Here, we investigate issues related to implementing qubits with phosphorus donors in silicon, employing an effective mass theory that non-phenomenologically takes into account inter-valley coupling. We estimate the significant sources of decoherence and control errors in this system to compute the fidelity of primitive gates and gate timescales. We include the effects of valley repopulation during the process of shuttling an electron between a donor and nearby interface or between neighboring donors, evaluating the control requirements for ensuring adiabaticity with respect to the valley sector. This work was supported in part by the LDRD program at Sandia National Labs, a multi-program laboratory managed and operated by Sandia Corp, a wholly owned subsidiary of Lockheed Martin Corp, for the U.S. DOE NNSA under contract DE-AC04-94AL85000.

  18. Electrostatically defined silicon quantum dots with counted antimony donor implants

    NASA Astrophysics Data System (ADS)

    Singh, M.; Pacheco, J. L.; Perry, D.; Garratt, E.; Ten Eyck, G.; Bishop, N. C.; Wendt, J. R.; Manginell, R. P.; Dominguez, J.; Pluym, T.; Luhman, D. R.; Bielejec, E.; Lilly, M. P.; Carroll, M. S.

    2016-02-01

    Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. In this work, a focused ion beam is used to implant antimony donors in 100 nm × 150 nm windows straddling quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of donors implanted can be counted to a precision of a single ion. In low-temperature transport measurements, regular Coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization are also observed in devices with counted donor implants.

  19. Replacing antibodies with aptamers in lateral flow immunoassay.

    PubMed

    Chen, Ailiang; Yang, Shuming

    2015-09-15

    Aptamers have been identified against various targets as a type of chemical or nucleic acid ligand by systematic evolution of ligands by exponential enrichment (SELEX) with high sensitivity and specificity. Aptamers show remarkable advantages over antibodies due to the nucleic acid nature and target-induced structure-switching properties and are widely used to design various fluorescent, electrochemical, or colorimetric biosensors. However, the practical applications of aptamer-based sensing and diagnostics are still lagging behind those of antibody-based tests. Lateral flow immunoassay (LFIA) represents a well established and appropriate technology among rapid assays because of its low cost and user-friendliness. The antibody-based platform is utilized to detect numerous targets, but it is always hampered by the antibody preparation time, antibody stability, and effect of modification on the antibody. Seeking alternatives to antibodies is an area of active research and is of tremendous importance. Aptamers are receiving increasing attention in lateral flow applications because of a number of important potential performance advantages. We speculate that aptamer-based LFIA may be one of the first platforms for commercial use of aptamer-based diagnosis. This review first gives an introduction to aptamer including the selection process SELEX with its focus on aptamer advantages over antibodies, and then depicts LFIA with its focus on aptamer opportunities in LFIA over antibodies. Furthermore, we summarize the recent advances in the development of aptamer-based lateral flow biosensing assays with the aim to provide a general guide for the design of aptamer-based lateral flow biosensing assays. PMID:25912679

  20. Surveillance of Fungal Allergic Sensitization Using the Fluorescent Halogen Immunoassay

    PubMed Central

    Green, Brett J.; Tovey, Euan R.; Beezhold, Donald H.; Perzanowski, Matthew S.; Acosta, Luis M.; Divjan, Adnan I.; Chew, Ginger L.

    2010-01-01

    SUMMARY Objective Conidia derived from a small number of common fungal genera are widely accepted as the etiological agents responsible for fungal allergic sensitization. The contribution of fungal conidia, spores, airborne hyphae, and subcellular fragments from other uncharacterized fungal genera remains unclear. In this proof-of-concept study, we examined the composition of mycoaerosols that atopic women were exposed and sensitized to in their own indoor environment using the fluorescent halogen immunoassay (fHIA). Patients and Methods Mycoaerosols were collected onto mixed cellulose ester protein binding membranes (PBMs) for 30 minutes with volumetric air sampling pumps. The PBMs were laminated with an adhesive cover slip and indirectly immunostained with individual patient serum IgE using the fHIA. Samples were examined using confocal laser scanning microscopy and immunostained particles were expressed as a percentage of total particles. Results All air samples contained a broad spectrum of fungal spores, conidia, hyphae, and other fungal particulates. Airborne concentrations varied between individual study participant environments. Positively immunostained conidia belonging to moniliaceous amerospores, Cladosporium, Alternaria, and many unknown species were observed in the majority of air samples. Other fungal genera including Bipolaris, Curvularia, Pithomyces, and Stachybotrys, in addition to, ascospore genera and dematiaceous hyphal fragments released detectable allergen. Twelve percent of all fHIA haloes quantified in the analysis were directed towards fungal particles. No immunostaining was detected to conidia belonging to Epicoccum, Fusarium, and Spegazzinia species. Conclusion In addition to characterized fungal aeroallergens, we observed a wider composition of fungi that bound human IgE. Field surveillance studies that utilize immunodiagnostic techniques such as the fHIA will provide further insight into the diversity of fungi that function as aeroallergen sources in individual study participant environments. PMID:20495612

  1. Monoclonal IgA Antibodies for Aflatoxin Immunoassays

    PubMed Central

    Ertekin, Özlem; Pirinçci, Şerife Şeyda; Öztürk, Selma

    2016-01-01

    Antibody based techniques are widely used for the detection of aflatoxins which are potent toxins with a high rate of occurrence in many crops. We developed a murine monoclonal antibody of immunoglobulin A (IgA) isotype with a strong binding affinity to aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and aflatoxin M1 (AFM1). The antibody was effectively used in immunoaffinity column (IAC) and ELISA kit development. The performance of the IACs was compatible with AOAC performance standards for affinity columns (Test Method: AOAC 991.31). The total binding capacity of the IACs containing our antibody was 111 ng, 70 ng, 114 ng and 73 ng for AFB1, AFB2, and AFG1 andAFG2, respectively. Furthermore, the recovery rates of 5 ng of each AF derivative loaded to the IACs were determined as 104.9%, 82.4%, 85.5% and 70.7% for AFB1, AFB2, AFG1 and AFG2, respectively. As for the ELISA kit developed using non-oriented, purified IgA antibody, we observed a detection range of 2–50 µg/L with 40 min total test time. The monoclonal antibody developed in this research is hitherto the first presentation of quadruple antigen binding IgA monoclonal antibodies in mycotoxin analysis and also the first study of their utilization in ELISA and IACs. IgA antibodies are valuable alternatives for immunoassay development, in terms of both sensitivity and ease of preparation, since they do not require any orientation effort. PMID:27187470

  2. Evaluation of the siemens HIV antigen-antibody immunoassay.

    PubMed

    Vallefuoco, Luca; Aden Abdi, Fatima; Sorrentino, Rosanna; Spalletti-Cernia, Daniela; Mazzarella, Claudia; Barbato, Sara; Perna, Enzo; Buffolano, Wilma; Di Nicuolo, Giuseppe; Portella, Giuseppe

    2014-01-01

    Fourth-generation assays for the simultaneous detection of human immunodeficiency virus (HIV) antigen and antibodies are available on the international market and are currently used for blood donor screening and for HIV diagnosis. In this study we evaluated the performance of the novel automated fourth-generation ADVIA Centaur® HIV Ag/Ab Combo assay. The assay detected seroconversion at the same bleed or at least one bleed earlier in panels with respect to other assays and showed a detection efficacy equal to those of other assays in a low-titer panel. Samples obtained from blood donors (n = 2,778) or from HIV-positive patients (HIV-1 B subtype, n = 82; non-B subtype, n = 71) were also tested, showing a good correlation with other fourth-generation assays. We assessed the performance of 3 fourth-generation assays for detecting in utero transmitted anti-HIV antibodies and found a more specific detection efficiency with the ADVIA Centaur HIV Ag/Ab Combo assay compared to the other fourth-generation assays. PMID:24557036

  3. Comparison of five enzyme immunoassays, electron microscopy, and latex agglutination for detection of rotavirus in fecal specimens.

    PubMed Central

    Kok, T W; Burrell, C J

    1989-01-01

    Five different enzyme immunoassays, electron microscopy, and latex agglutination (Slidex; bioMerieux) were compared for the rapid detection of human rotavirus in fecal specimens. The enzyme immunoassay using rotavirus polyclonal antiserum (Dakopatts) with simple in-house modifications was shown by the use of confirmatory tests to be the most sensitive and specific procedure. PMID:2536758

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

    PubMed

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

    2014-07-17

    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

  5. Evaluation of a competitive immunoassay for the detection of bovine haptoglobin.

    PubMed

    McNair, J; Kennedy, D G; Bryson, D G; Reilly, G A; McDowell, S W; Mackie, D P

    1997-01-01

    A competitive immunoassay to quantify the serum concentration of bovine haptoglobin (hp) using time resolved fluorescence was compared with an indirect method of hp assay (haemoglobin binding assay), using sera taken from healthy animals (n = 158), animals experimentally infected with Haemophilus somnus (n = 10) and from sick animals requiring veterinary treatment (n = 440). Upper limits of normality (for normal animals) were tentatively established for the immunoassay (2.1 micrograms ml-1) and for the haemoglobin binding assay (103 micrograms ml-1). The competitive immunoassay detected elevated hp in 62.5 per cent of field sera by comparison with only 19.2 per cent using the conventional haemoglobin binding assay. Serum albumin concentration did not correlate with hp although concentrations of globulins and copper did correlate. However, these parameters (serum globulin and copper) were found to be insensitive markers of inflammatory disease. PMID:9429248

  6. Preparation of biotinylated cypridina luciferase and its use in bioluminescent enzyme immunoassay.

    PubMed

    Wu, Chun; Kawasaki, Kosei; Ogawa, Yoko; Yoshida, Yasukazu; Ohgiya, Satoru; Ohmiya, Yoshihiro

    2007-02-15

    Cypridina luciferase, a well-known secretory enzyme involved in the bioluminescence of marine ostracod, is used to monitor gene expression in mammalian cells. Here we report the preparation of biotinylated Cypridina luciferase and its use in bioluminescent enzyme immunoassay (BLEIA). Recombinant Cypridina luciferase was expressed in yeast and successfully purified to near homogeneity. The luciferase was biotinylated with conventional biotinylation reagents, and the biotinylated lysine sites were determined by liquid chromatography-tandem mass spectrometry. The biotinylated luciferase was stable when stored at 4 degrees C. The stability of synthetic S-Cypridina luciferin was significantly improved by adding antioxidants to Tris-HCl buffer. The biotinylated luciferase and S-Cypridina luciferin were used in a model study of the immunoassay for interferon-alpha. The linearity of this immunoassay extended from 7.8 to 500 pg/mL interferon-alpha. Our results show that Cypridina luciferase is a very sensitive and versatile bioluminescent reporter. PMID:17297966

  7. Chemiluminescence lateral flow immunoassay based on Pt nanoparticle with peroxidase activity.

    PubMed

    Park, Jong-Min; Jung, Ha-Wook; Chang, Young Wook; Kim, Hyung-Seok; Kang, Min-Jung; Pyun, Jae-Chul

    2015-01-01

    A lateral flow immunoassay (LF-immunoassay) with an enhanced sensitivity and thermostability was developed by using Pt nanoparticles with a peroxidase activity. The Pt nanoparticles were synthesized by citrate reduction method, and the peroxidase activity of Pt nanoparticles was optimized by adjusting reaction conditions. The peroxidase activity was estimated by using Michaelis-Menten kinetics model with TMB as a chromogenic substrate. The kinetics parameters of KM and Vmax were calculated and compared with horseradish peroxidase (HRP). The thermal stability of the Pt nanoparticles was compared with horseradish peroxidase (HRP) according to the storage temperature and long-term storage period. The feasibility of lateral flow immunoassay with a chemiluminescent signal band was demonstrated by the detection of human chorionic gonadotropin (hCG) as a model analyte, and the sensitivity was determined to be improved by as much as 1000-fold compared to the conventional rapid test based on colored gold-colloids. PMID:25467480

  8. Magnetic enzyme immunoassay of anti-grass pollen specific-IgE in human sera.

    PubMed Central

    Guesdon, J L; David, B; Lapeyre, J

    1978-01-01

    This paper reports a magnetic solid-phase sandwich enzyme immunoassay for specific IgE antibodies in human sera. Crude extracts of grass pollen bound to magnetic polyacrylamide agarose beads were mixed with human serum to be tested. After washing in a magnetic rack, the beads were incubated with the glucose-oxidase-labelled sheep anti-IgE. The enzyme activity associated with the beads was measured by colorimetric assay. Results obtained from sixty-one human sera, as measured by the magnetic enzyme immunoassay, gave a linear correlation coefficient of 0.98 with the values as determined by radio-immunoassay. This procedure, which allows the grass pollen specific IgE in human sera, to be measured, is easy to perform, reproducible and may avoid the use of radioactive compounds. PMID:367648

  9. Comparison of an enzyme immunoassay with electron microscopic procedures for detecting rotavirus.

    PubMed Central

    Rubenstein, A S; Miller, M F

    1982-01-01

    The sensitivity and specificity of an enzyme immunoassay (Rotazyme), an ongrid immunoelectron microscopy procedure, and conventional negative stain electron microscopic techniques were compared. By using partially purified human rotavirus and simian rotavirus (SA-11) of known particle concentration, the enzyme immunoassay was essentially equivalent to the immunoelectron microscopic procedure and significantly more sensitive than conventional electron microscopic techniques. The level of sensitivity was approximately 10(6) particles per ml for simian rotavirus SA-11 and 10(7) particles per ml for human rotavirus. In an evaluation of 455 clinical samples by these techniques, a sensitivity of 98% and specificity of 92% were demonstrated. Samples negative by the immunoelectron microscopic procedure and positive by enzyme immunoassay could be confirmed by a blocking assay. Images PMID:6284793

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

    PubMed Central

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

    2011-01-01

    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. PMID:22164051

  11. Optimizing two-color semiconductor nanocrystal immunoassays in single well microtiter plate formats.

    PubMed

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

    2011-01-01

    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. PMID:22164051

  12. Achieving donor repetition and motivation by block leaders among current blood donors.

    PubMed

    Martín-Santana, Josefa D; Beerli-Palacio, Asunción

    2012-12-01

    This paper presents an explicative model on the recommendation of donating blood made to relatives and friends by current donors. This model establishes satisfaction and intention to return as direct antecedents, and the quality perceived in the donation process and the existence of inhibitors as indirect antecedents. The results show that (1) the perceived quality has a positive influence on satisfaction and intention to return; (2) the intention to donate again depends positively on satisfaction, but negatively on the existence of internal and external inhibitors; and lastly (3) the recommendation to donate depends on donor satisfaction and their intention to return to donate, this being the most influential factor. At the same time, we contrasted how the model does not vary, whether it is a first-time donor or a repeat donor. PMID:22683233

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

    PubMed

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

    2014-06-11

    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

  14. Donor liver dysfunction: application of a new scoring system to identify the marginal donor.

    PubMed

    Ferraz-Neto, B H; Zurstrassen, M P V C; Hidalgo, R; Fonseca, L E P; Motta, T D B; Pandullo, F L; Rezende, M B; Meira-Filho, S P; S, J R; Afonso, R C

    2007-10-01

    Livers from marginal donors are increasingly used for transplantation due to the shortage of donor organs. The definition of a marginal donor remains unclear; prediction of organ function is a challenge. In the literature the use of steatotic livers has been associated with poor liver function or even primary dysfunction of the allograft. Tekin et al created a scoring system that classifies a donor as marginal or nonmarginal, using a mathematical model based on donor age and steatosis degree. The aims of this study were to apply the Tekin method to identify marginal and nonmarginal donors and evaluate the influence of the cold ischemia time (CIT) on allograft evolution. We retrospectively reviewed deceased donor liver transplantations performed from October 1995 to March 2006, namely, 177 adult liver transplantations in 163 patients. Fifty-five were excluded due to retransplantation (14) or insufficient data (41). Donor age and macrovesicular steatosis were evaluated according to the mathematical formula proposed by Tekin et al, classifying the donors as marginal versus nonmarginal. The authors also analyzed the CIT, 3-month mortality, and development of primary nonfunction or primary dysfunction. The median donor age was 38.9 years (range, 6-71). The postreperfusion biopsy specimen showed moderate to intense steatosis (>30%) in 14.75% of specimens, with no steatosis or mild steatosis in 85.25%. Sixty-one grafts (50%) developed primary graft dysfunction (PGD): 10 grafts, with primary nonfunction (PNF); and 51 with initial poor function (IPF). Using the criteria provided by Tekin et al, we obtained 41 marginal and 81 nonmarginal allografts. The marginal group showed 61.9% PGD, compared with 59.2% of PGD by the nonmarginal group. The CIT was greater than 12 hours in 5 marginal group transplants and 4 PGD cases (80%). Of the nonmarginal allografts, the CIT was greater than 12 hours in 29.6%, with 75% PGD. The 3-month graft survival rate was 80% in the marginal group with ischemia time more than 12 hours: 86.1% of the same group when CIT was less than 12 hours, and 82.7% in the nonmarginal group. In contrast, when we analyzed the occurrence of allograft dysfunction, the 3-month mortality rate was 34% among, grafts with dysfunction, whereas, in those without initial dysfunction, it was 4.1%. In conclusion, the score suggested by Tekin et al that classifies the donors as ideal (nonmarginal) or marginal was not able to predict initial primary dysfunction. PMID:17954162

  15. Kidney Function and Plasma Copeptin Levels in Healthy Kidney Donors and Autosomal Dominant Polycystic Kidney Disease Patients

    PubMed Central

    Zittema, Debbie; van den Berg, Else; Meijer, Esther; Boertien, Wendy E.; Muller Kobold, Anneke C.; Franssen, Casper F.M.; de Jong, Paul E.; Bakker, Stephan J.L.; Navis, Gerjan

    2014-01-01

    Background and objectives Plasma copeptin, a marker of arginine vasopressin, is elevated in patients with autosomal dominant polycystic kidney disease and predicts disease progression. It is unknown whether elevated copeptin levels result from decreased kidney clearance or as compensation for impaired concentrating capacity. Data from patients with autosomal dominant polycystic kidney disease and healthy kidney donors before and after donation were used, because after donation, overall GFR decreases with a functionally normal kidney. Design, setting, participants, & measurements Data were obtained between October of 2008 and January of 2012 from healthy kidney donors who visited the institution for routine measurements predonation and postdonation and patients with autosomal dominant polycystic kidney disease who visited the institution for kidney function measurement. Plasma copeptin levels were measured using a sandwich immunoassay, GFR was measured as 125I-iothalamate clearance, and urine concentrating capacity was measured as urine-to-plasma ratio of urea. In patients with autosomal dominant polycystic kidney disease, total kidney volume was measured with magnetic resonance imaging. Results Patients with autosomal dominant polycystic kidney disease (n=122, age=40 years, men=56%) had significantly higher copeptin levels (median=6.8 pmol/L; interquartile range=3.4–15.7 pmol/L) compared with donors (n=134, age=52 years, men=49%) both predonation and postdonation (median=3.8 pmol/L; interquartile range=2.8–6.3 pmol/L; P<0.001; median=4.4 pmol/L; interquartile range=3.6–6.1 pmol/L; P<0.001). In donors, copeptin levels did not change after donation, despite a significant fall in GFR (from 105±17 to 66±10; P<0.001). Copeptin and GFR were significantly associated in patients with autosomal dominant polycystic kidney disease (β=−0.45, P<0.001) but not in donors. In patients with autosomal dominant polycystic kidney disease, GFR and total kidney volume were both associated significantly with urine-to-plasma ratio of urea (β=0.84, P<0.001; β=−0.51, P<0.001, respectively). Conclusions On the basis of the finding in donors that kidney clearance is not a main determinant of plasma copeptin levels, it was hypothesized that, in patients with autosomal dominant polycystic kidney disease, kidney damage and associated impaired urine concentration capacity determine copeptin levels. PMID:24993447

  16. Using cheminformatics to predict cross reactivity of “designer drugs” to their currently available immunoassays

    PubMed Central

    2014-01-01

    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. PMID:24851137

  17. Diagnostic value of immunoassays for heparin-induced thrombocytopenia: a systematic review and meta-analysis.

    PubMed

    Nagler, Michael; Bachmann, Lucas M; Ten Cate, Hugo; Ten Cate-Hoek, Arina

    2016-02-01

    Immunoassays are essential in the workup of patients with suspected heparin-induced thrombocytopenia. However, the diagnostic accuracy is uncertain with regard to different classes of assays, antibody specificities, thresholds, test variations, and manufacturers. We aimed to assess diagnostic accuracy measures of available immunoassays and to explore sources of heterogeneity. We performed comprehensive literature searches and applied strict inclusion criteria. Finally, 49 publications comprising 128 test evaluations in 15?199 patients were included in the analysis. Methodological quality according to the revised tool for quality assessment of diagnostic accuracy studies was moderate. Diagnostic accuracy measures were calculated with the unified model (comprising a bivariate random-effects model and a hierarchical summary receiver operating characteristics model). Important differences were observed between classes of immunoassays, type of antibody specificity, thresholds, application of confirmation step, and manufacturers. Combination of high sensitivity (>95%) and high specificity (>90%) was found in 5 tests only: polyspecific enzyme-linked immunosorbent assay (ELISA) with intermediate threshold (Genetic Testing Institute, Asserachrom), particle gel immunoassay, lateral flow immunoassay, polyspecific chemiluminescent immunoassay (CLIA) with a high threshold, and immunoglobulin G (IgG)-specific CLIA with low threshold. Borderline results (sensitivity, 99.6%; specificity, 89.9%) were observed for IgG-specific Genetic Testing Institute-ELISA with low threshold. Diagnostic accuracy appears to be inadequate in tests with high thresholds (ELISA; IgG-specific CLIA), combination of IgG specificity and intermediate thresholds (ELISA, CLIA), high-dose heparin confirmation step (ELISA), and particle immunofiltration assay. When making treatment decisions, clinicians should be a aware of diagnostic characteristics of the tests used and it is recommended they estimate posttest probabilities according to likelihood ratios as well as pretest probabilities using clinical scoring tools. PMID:26518436

  18. Diverse patterns of recognition of hepatitis C virus core and nonstructural antigens by antibodies present in Egyptian cancer patients and blood donors.

    PubMed Central

    Attia, M A; Zekri, A R; Goudsmit, J; Boom, R; Khaled, H M; Mansour, M T; de Wolf, F; el-Din, H M; Sol, C J

    1996-01-01

    Serum samples from 429 cancer patients, 82 unpaid blood donors, and 74 paid blood donors were tested for hepatitis C virus (HCV) markers in two commercially available enzyme immunoassays (EIAs). A total of 229 of 429 (53.4%) cancer patients were positive by the two EIAs. A total of 34 of 156 (21.8%) of the blood donors were positive by the EIAs, with a higher prevalence among paid blood donors (20/74; 27%) compared with that among the unpaid blood donors (14 of 82; 17%). EIA-positive sera were tested for confirmation of the results in an immunoblot assay (LiaTek) in which reactivities to four synthetic peptides representing the HCV core protein and two synthetic peptides representing nonstructural proteins 4 and 5 were measured. Of 243 first and/or second EIA-positive samples from cancer patients, 188 (77.2%) were confirmed to be positive in the synthetic peptide immunoblot. A total of 33 of 35 (94.3%) blood donor samples were confirmed to be positive. A great diversity in reactivity patterns was seen. However, all sera from the group of paid blood donors were exclusively reactive to core peptides 1 and 2. A subset of LiaTek assay-positive samples were tested by the four-antigen RIBA-2 assay. The sera from the paid blood donors were all nonreactive. A subset of the LiaTek-positive sera was analyzed for the presence of the HCV genome by reverse transcriptase-PCR. Eleven of the 20 serum samples with reactivity to LiaTek core peptides 1 and 2 only were HCV reverse transcriptase-PCR positive, as were the majority of the sera with other reactivity patterns by the LiaTek assay. The results confirm the very high prevalence of HCV infection in Egypt. Furthermore, the results indicate that there is circulating in Egypt, particularly in the group of blood donors paid for their donation, an HCV variant which elicits an immune response that is not detected by the RIBA-2 assay. PMID:8897161

  19. Characteristics of Human Turbinate-Derived Mesenchymal Stem Cells Are Not Affected by Allergic Condition of Donor

    PubMed Central

    Hwang, Se Hwan; Cho, Hye Kyung; Park, Sang Hi; Lee, WeonSun; Lee, Hee Jin; Lee, Dong Chang; Park, Sun Hwa; Lim, Mi Hyun; Back, Sang A; Yun, Byeong Gon; Sun, Dong Il

    2015-01-01

    The characteristics of mesenchymal stem cells (MSCs) derived from human turbinates (hTMSCs) have not been investigated in allergic rhinitis. We evaluated the influence of allergic state of the donor on the characteristics, proliferation, and differentiation potential of hTMSCs, compared with hTMSCs derived from non-allergic patients. hTMSCs were isolated from five non-allergic and five allergic patients. The expression of toll-like receptors (TLRs) in hTMSCs was measured by FACS, and cell proliferation was measured using a cell counting kit. Cytokine secretion was analyzed using multiplex immunoassays. The osteogenic, chondrogenic, and adipogenic differentiation potentials of hTMSCs were evaluated by histology and gene expression analysis. In allergic patients, FACS analysis showed that TLR3 and TLR4 were more highly expressed on the surface of hTMSCs than TLR2 and TLR5. The proliferation of hTMSCs was not influenced by the presence of TLR priming. The expression of IL-6, IL-8, IL-12, IP-10, and RANTES was upregulated after the TLR4 priming. The differentiation potential of hTMSCs was not influenced by TLR priming. These characteristics of hTMSCs were similar to those of hTMSCs from non-allergic patients. We conclude that the allergic condition of the donor does not influence TLR expression, proliferation, or immunomodulatory potential of hTMSCs. PMID:26376485

  20. Measurement of anti-Mullerian hormone: performances of a new ultrasensitive immunoassay.

    PubMed

    Gruson, Damien; Homsak, Evgenija

    2015-04-01

    The measurement of anti-Mullerian hormone (AMH) is relevant for the evaluation of primary ovarian insufficiency, success of assisted reproductive therapies, and also to support the diagnosis of polycystic ovary syndrome. Our study demonstrated excellent analytical performances for the Ansh Laboratories AMH immunoassay and an overall good agreement with the AMH Gen II assay. Nevertheless, the two AMH immunoassays are not using the same couple of antibodies and therefore not commutable and the definition of specific reference values and cut-point remains necessary. PMID:25575745

  1. Blood Donors Needed After East Coast Storm: Red Cross

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_156902.html Blood Donors Needed After East Coast Storm: Red Cross Many ... by the winter storm are encouraged to make blood and platelet donations, the Red Cross said. Donors in areas affected ...

  2. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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...

  3. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) BIOLOGICS 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...

  4. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) BIOLOGICS 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...

  5. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) BIOLOGICS 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...

  6. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  7. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) BIOLOGICS 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...

  8. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  9. 21 CFR 640.12 - Suitability of donor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

  10. 21 CFR 660.31 - Suitability of the donor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) BIOLOGICS 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...

  11. Easy come, easy go. Retention of blood donors.

    PubMed

    van Dongen, A

    2015-08-01

    Retention of blood donors has benefits over recruitment of new blood donors. Retention is defined as preventing donors from lapsing and eventually becoming inactive. This review paper discusses literature on the importance of efforts to retain donors, specifically new donors, since lapsing is most common before the fifth donation. Studies have found that intention to donate, attitudes towards blood donation and self-efficacy (does one feel capable of donating blood) are predictors of blood donation. Feelings of 'warm glow' predict donation behaviour better than altruism. The existing literature further suggests that first time donors can be retained by paying extra attention to adverse events (vasovagal reactions and fatigue). These events could be reduced by drinking water and muscle tension exercises. Feelings of anxiety (in regular donors) and stress can further prevent donors from returning. Planning donations amongst busy lives can help retention, and suggestions are given on which interventions might be helpful. PMID:26399971

  12. Hand-assisted laparoscopic living-donor nephrectomy as an alternative to traditional laparoscopic living-donor nephrectomy.

    PubMed

    Buell, Joseph F; Hanaway, Michael J; Potter, Steven R; Cronin, David C; Yoshida, Atsushi; Munda, Rino; Alexander, J Wesley; Newell, Kenneth A; Bruce, David S; Woodle, E Steve

    2002-11-01

    The benefits of laparoscopic living-donor nephrectomy (LDN) are well described, while similar data on hand-assisted laparoscopic living-donor nephrectomy (HALDN) are lacking. We compare hand-assisted laparoscopic living-donor nephrectomy with open donor nephrectomy. One hundred consecutive hand-assisted laparoscopic living-donor nephrectomy (10/98-8/01) donor/recipient pairs were compared to 50 open donor nephrectomy pairs (8/97-1/00). Mean donor weights were similar (179.6 +/- 40.8 vs. 167.4 +/- 30.3 lb; p = NS), while donor age was greater among hand-assisted laparoscopic living-donor nephrectomy (38.2 +/- 9.5 vs. 31.2 +/- 7.8 year; p < 0.01). Right nephrectomies was fewer in hand-assisted laparoscopic living-donor nephrectomy [17/100 (17%) vs. 22/50 (44%); p < 0.05]. Operative time for hand-assisted laparoscopic living-donor nephrectomy (3.9 +/- 0.7 vs. 2.9 +/- 0.5 h; p < 0.01) was longer; however, return to diet (6.9 +/- 2.8 vs. 25.6 +/- 6.1 h; p < 0.01), narcotics requirement (17.9 +/- 6.3 vs. 56.3 +/- 6.4h; p < 0.01) and length of stay (51.7 +/- 22.2 vs. 129.6 +/- 65.7 h; p < 0.01) were less than open donor nephrectomy. Costs were similar ($11072 vs. 10840). Graft function and 1-week Cr of 1.4 +/- 0.9 vs. 1.6 +/- 1.1 g/dL (p = NS) were similar. With the introduction of HALDN, our laparoscopic living-donor nephrectomy program has increased by 20%. Thus, similar to traditional laparoscopic donor nephrectomy, hand-assisted laparoscopic living-donor nephrectomy provides advantages over open donor nephrectomy without increasing costs. PMID:12482153

  13. Imaging in Lung Transplantation: Surgical Considerations of Donor and Recipient.

    PubMed

    Backhus, Leah M; Mulligan, Michael S; Ha, Richard; Shriki, Jabi E; Mohammed, Tan-Lucien H

    2016-03-01

    Modifications in recipient and donor criteria and innovations in donor management hold promise for increasing rates of lung transplantation, yet availability of donors remains a limiting resource. Imaging is critical in the work-up of donor and recipient including identification of conditions that may portend to poor posttransplant outcomes or necessitate modifications in surgical technique. This article describes the radiologic principles that guide selection of patients and surgical procedures in lung transplantation. PMID:26896228

  14. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  15. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  16. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  17. 21 CFR 640.63 - Suitability of donor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.63 Suitability of donor. (a) Method of determining. The suitability of a donor for Source Plasma shall be determined by a qualified... year. (2)(i) A donor who is to be immunized for the production of high-titer plasma shall be...

  18. Living donor liver transplantation in Europe

    PubMed Central

    Capobianco, Ivan; Panaro, Fabrizio; Di Francesco, Fabrizio; Troisi, Roberto; Sainz-Barriga, Mauricio; Muiesan, Paolo; Königsrainer, Alfred; Testa, Giuliano

    2016-01-01

    Living donor liver transplantation (LDLT) sparked significant interest in Europe when the first reports of its success from USA and Asia were made public. Many transplant programs initiated LDLT and some of them especially in Germany and Belgium became a point of reference for many patients and important contributors to the advancement of the field. After the initial enthusiasm, most of the European programs stopped performing LDLT and today the overall European activity is concentrated in a few centers and the number of living donor liver transplants is only a single digit fraction of the overall number of liver transplants performed. In this paper we analyse the present European activities and highlight the European contribution to the advancement of the field of LDLT. PMID:27115011

  19. Diet and Asthma: Vitamins and Methyl Donors

    PubMed Central

    Han, Yueh-Ying; Blatter, Josh; Brehm, John M.; Forno, Erick; Litonjua, Augusto A; Celedn, Juan C.

    2014-01-01

    SUMMARY Dietary changes may partly explain the high burden of asthma in industrialized nations. Experimental studies have motivated a significant number of observational studies of the relation between vitamins (A, C, D, and E) or nutrients acting as methyl donors (folate, vitamin B12, and choline) and asthma. Because observational studies are susceptible to several sources of bias, well-conducted randomized controlled trials (RCTs) remain the gold standard to determine whether a vitamin or nutrient has an effect on asthma. Evidence from observational studies and/or relatively few RCTs most strongly justify ongoing and future RCTs of: 1) vitamin D to prevent or treat asthma, 2) choline supplementation as adjuvant treatment for asthma, and 3) vitamin E to prevent the detrimental effects of air pollution in subjects with asthma. At this time, there is insufficient evidence to recommend supplementation with any vitamin or nutrient acting as a methyl donor to prevent or treat asthma. PMID:24461761

  20. [Management of the potential organ donor].

    PubMed

    Bugedo, Guillermo; Bravo, Sebastián; Romero, Carlos; Castro, Ricardo

    2014-12-01

    Solid organ transplantation is limited by donor availability. The loss of brain function produces hemodynamic, respiratory, hormonal and metabolic changes that lead to hypotension and organ dysfunction. Management of a potential donor is similar to any critically ill patient. Cardiovascular stability and protective ventilatory support must be pursued, aimed at minimizing the local and systemic inflammatory response that is triggered by brain death. There is no consensus on protocols for hormonal supplementation. The administration of vasopressin analogues and steroids may be beneficial under certain conditions. Appropriate medical management helps to optimize the function of different organs prior to transplantation. This may increase the number of harvested organs and improve their functional outcome in the recipient. PMID:25693441

  1. Current strategies in donor selection and management.

    PubMed

    Botha, Phil; Rostron, Anthony J; Fisher, Andrew J; Dark, John H

    2008-01-01

    Lung donor selection and management strategy continues to evolve, driven by the scarcity of donor lungs suitable for transplantation and the ever present risk of primary graft dysfunction. Selection, based both on data available at referral and that added by the retrieval team, was traditionally based on the transplant surgeon's clinical experience. Closely analyzed clinical data on factors such as age, gas exchange, gram-stain, and even cytokine expression now allow increased objectivity of decision making. By contrast, the importance of variables such as length of ventilation and even ischemic time remain obscure. Optimal management, the key to promoting the marginal lung toward the ideal, is soundly based on the rapidly increasing appreciation of the pathophysiology of brain-stem death. Algorithms based on this knowledge can be proposed with some confidence, but proving their clinical worth is a challenge for the future. PMID:18707649

  2. Psychiatric Aspects of Artificial Insemination (Donor)

    PubMed Central

    Watters, W. W.; Sousa-Poza, J.

    1966-01-01

    Artificial insemination (donor) [A.I.D.] in humans is a medical procedure that has been carried out for roughly 50 years. Its legal status has not yet been established; its moral implications are still hotly contested, and its psychological and psychiatric implications are only now coming under scientific scrutiny. The use of this procedure in couples who are psychologically unsuited for it can have unfortunate consequences. The obstetrician should seek the assistance of a dynamically oriented psychiatrist in screening couples who ask for artificial insemination (donor). Parenthood, in line with psychoanalytic ego psychology, is seen as a phase of ego development. The potential for mothering and fathering children is a later stage in growth than the capacity to conceive and sire them. It is the psychiatrist's role to assess the couple's motivation for A.I.D. in the light of the extent to which they have achieved this degree of ego development. PMID:20328602

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

    SciTech Connect

    Wadhwa, Ashutosh; Foote, Robert; Shaw, Robert W; Eda, Shigetoshi

    2012-01-01

    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.

  4. Multiplex Serum Cytokine Immunoassay Using Nanoplasmonic Biosensor Microarrays

    PubMed Central

    Chen, Pengyu; Chung, Meng Ting; McHugh, Walker; Nidetz, Robert; Li, Yuwei; Fu, Jianping; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo

    2015-01-01

    Precise monitoring of the rapidly changing immune status during the course of a disease requires multiplex analysis of cytokines from frequently sampled human blood. However, the current lack of rapid, multiplex, and low volume assays makes immune monitoring for clinical decision-making (e.g., critically ill patients) impractical. Without such assays, immune monitoring is even virtually impossible for infants and neonates with infectious diseases and/or immune mediated disorders as access to their blood in large quantities is prohibited. Localized surface plasmon resonance (LSPR)-based microfluidic optical biosensing is a promising approach to fill this technical gap as it could potentially permit real-time refractometric detection of biomolecular binding on a metallic nanoparticle surface and sensor miniaturization, both leading to rapid and sample-sparing analyte analysis. Despite this promise, practical implementation of such a microfluidic assay for cytokine biomarker detection in serum samples has not been established primarily due to the limited sensitivity of LSPR biosensing. Here, we developed a high-throughput, label-free, multiarrayed LSPR optical biosensor device with 480 nanoplasmonic sensing spots in microfluidic channel arrays and demonstrated parallel multiplex immunoassays of six cytokines in a complex serum matrix on a single device chip while overcoming technical limitations. The device was fabricated using easy-to-implement, one-step microfluidic patterning and antibody conjugation of gold nanorods (AuNRs). When scanning the scattering light intensity across the microarrays of AuNR ensembles with dark-field imaging optics, our LSPR biosensing technique allowed for high-sensitivity quantitative cytokine measurements at concentrations down to 5–20 pg/mL from a 1 µL serum sample. Using the nanoplasmonic biosensor microarray device, we demonstrated the ability to monitor the inflammatory responses of infants following cardiopulmonary bypass (CPB) surgery through tracking the time-course variations of their serum cytokines. The whole parallel on-chip assays, which involved the loading, incubation, and washing of samples and reagents, and 10-fold replicated multianalyte detection for each sample using the entire biosensor arrays, were completed within 40 min. PMID:25790830

  5. Multiplex serum cytokine immunoassay using nanoplasmonic biosensor microarrays.

    PubMed

    Chen, Pengyu; Chung, Meng Ting; McHugh, Walker; Nidetz, Robert; Li, Yuwei; Fu, Jianping; Cornell, Timothy T; Shanley, Thomas P; Kurabayashi, Katsuo

    2015-01-01

    Precise monitoring of the rapidly changing immune status during the course of a disease requires multiplex analysis of cytokines from frequently sampled human blood. However, the current lack of rapid, multiplex, and low volume assays makes immune monitoring for clinical decision-making (e.g., critically ill patients) impractical. Without such assays, immune monitoring is even virtually impossible for infants and neonates with infectious diseases and/or immune mediated disorders as access to their blood in large quantities is prohibited. Localized surface plasmon resonance (LSPR)-based microfluidic optical biosensing is a promising approach to fill this technical gap as it could potentially permit real-time refractometric detection of biomolecular binding on a metallic nanoparticle surface and sensor miniaturization, both leading to rapid and sample-sparing analyte analysis. Despite this promise, practical implementation of such a microfluidic assay for cytokine biomarker detection in serum samples has not been established primarily due to the limited sensitivity of LSPR biosensing. Here, we developed a high-throughput, label-free, multiarrayed LSPR optical biosensor device with 480 nanoplasmonic sensing spots in microfluidic channel arrays and demonstrated parallel multiplex immunoassays of six cytokines in a complex serum matrix on a single device chip while overcoming technical limitations. The device was fabricated using easy-to-implement, one-step microfluidic patterning and antibody conjugation of gold nanorods (AuNRs). When scanning the scattering light intensity across the microarrays of AuNR ensembles with dark-field imaging optics, our LSPR biosensing technique allowed for high-sensitivity quantitative cytokine measurements at concentrations down to 5-20 pg/mL from a 1 μL serum sample. Using the nanoplasmonic biosensor microarray device, we demonstrated the ability to monitor the inflammatory responses of infants following cardiopulmonary bypass (CPB) surgery through tracking the time-course variations of their serum cytokines. The whole parallel on-chip assays, which involved the loading, incubation, and washing of samples and reagents, and 10-fold replicated multianalyte detection for each sample using the entire biosensor arrays, were completed within 40 min. PMID:25790830

  6. Experimental hypersensitivity pneumonitis: influence of donor sensitization.

    PubMed

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

    1990-05-01

    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

  7. Significance of the donor age effect on kidney transplants.

    PubMed

    Terasaki, P I; Gjertson, D W; Cecka, J M; Takemoto, S; Cho, Y W

    1997-10-01

    The shortage of cadaveric donor kidneys for transplantation has forced a re-evaluation of the limits on donor age acceptability. However, as more kidneys from older donors have been transplanted, a significantly lower graft survival has been noted among their recipients. The impact of utilizing older donor kidneys and the relative importance of donor age with respect to other factors has not been clarified. A total of 43,172 cadaver donor transplants reported to the UNOS Scientific Renal Transplant Registry between 1987 and 1995 were the subjects of this study. Cox regression analysis was utilized to assess the joint effects on graft survival of donor age and HLA mismatch, recipient sex, race, age, original disease, donor death cause, cold ischemia time, and transplant year. Increased first day anuria, dialysis requirement, and discharge serum creatinine were noted with increasing donor age. Moreover, long-term graft and patient survival diminished as donor age increased. The 5-yr graft survival of zero HLA-A,B,DR mismatched kidneys fell steadily from 81% when the donor was aged 21-30 to 39% when the donor was over age 60. The reported causes of kidney transplant failure were remarkably similar for old and young donors. The best transplant results were obtained with zero HLA-A,B,DR mismatched transplants from young donors and the worst with older donor kidneys, regardless of HLA compatibility. We calculated that up to 21% of kidney failures resulted from insufficient renal mass due to age and were incorrectly attributed to chronic rejection. PMID:9361925

  8. 78 FR 66366 - Draft Guidance for Industry: Use of Donor Screening Tests To Test Donors of Human Cells, Tissues...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-05

    ...The Food and Drug Administration (FDA) is announcing the availability of a draft document entitled ``Guidance for Industry: Use of Donor Screening Tests to Test Donors of Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps) for Infection with Treponema pallidum (Syphilis),'' dated October 2013. The draft guidance document provides establishments that make donor eligibility......

  9. The donor, the father, and the imaginary constitution of the family: parents' constructions in the case of donor insemination.

    PubMed

    Grace, Victoria M; Daniels, Ken R; Gillett, Wayne

    2008-01-01

    Current international policy trends in the field of medically assisted conception are moving towards increased openness of information regarding the nature of conception where donated gametes are involved. In the case of donor insemination this means that the donor is no longer anonymous, offspring have the right to access information about the donor's identity, and parents are encouraged to tell children the nature of their donor-assisted conception. Until recently, however, the practice of donor insemination has tended to create the conditions for ignoring, or erasing, the existence of the donor as the provider of the gametes. Changing policy creates numerous challenges to this erasure, and to traditional conceptualisations of the father. This research is based on analysis of the narratives of a group of 41 New Zealand couples who conceived children with the assistance of donor insemination 15-18 years prior. This article focuses on their talk about the donor. The parents' negation of the donor supports the normative formation of 'family', and is in turn supported by an instrumental and de-personalising discourse in relation to the donor. A tension is created within the parents' talk whereby donors are negated and yet simultaneously appear as persons. We explore this discursive construction, suggesting that a new framework for thinking about donated gametes and the role of the donor is influencing parents' narrations and understandings of family. We discuss these influences and examine their implications, particularly with respect to a separation of the bio-genetic from the social-environmental. PMID:17928116

  10. Ultrasensitive electrochemical immunoassay of proteins based on in situ duple amplification of gold nanoparticle biolabel signals.

    PubMed

    Qin, Xiaoli; Xu, Aigui; Liu, Ling; Deng, Wenfang; Chen, Chao; Tan, Yueming; Fu, Yingchun; Xie, Qingji; Yao, Shouzhuo

    2015-05-18

    An electrochemical sandwich immunoassay method that can be sensitive to a few protein molecules (human immunoglobulin G or human prostate-specific antigen) is reported, based on HAuCl4-NH2OH redox reaction to enlarge the size of second antibody labeled gold nanoparticles and in situ microliter-droplet anodic stripping voltammetry analysis with enhanced cathodic preconcentration of gold. PMID:25894215

  11. Interference from endogenous antibodies in automated immunoassays: what laboratorians need to know.

    PubMed

    Ismail, A A A

    2009-08-01

    Full automation of laboratory procedures confers numerous advantages over semi-automated/manual tests because equipment, reagents and the computation of results are offered as an integrated package. Automation has allowed millions of immunoassay tests to be performed with good sensitivity and excellent precision but inaccuracy caused by interference from endogenous immunoglobulins/antibodies remained a problem (irrespective of the immunoassay's format). Interference leading to a falsely high or low result affects a specific sample and may not be obvious despite the strictest laboratory control schemes. Reporting and interpreting such potentially erroneous data remained however the responsibility of the clinical laboratory despite the limited information supplied by their providers. The focus of this review is on highlighting the potential downside of current disjointed and blurred arrangement between the developers/providers of immunoassays, and the laboratorians responsible for providing these data to their clinical colleagues. These limitations can be addressed by drawing attention to the importance of the key fundamentals underpinning these immunologically based analyses which, if carefully considered, could help to formulate pragmatic strategies to reduce errors in immunoassays. In this review, the inherent fallibility of the binding reaction between an antigen and antibody will be reiterated. The difficulties in defining reaction rate kinetics in non-equilibrium automated assays, the potential clinical error rate and the need for minimising analytical error rate of these automated technologies will be highlighted. PMID:19638536

  12. ENZYME-LINKED IMMUNOASSAYS FOR THE DETECTION OF MICROBIAL ANTIGENS AND THEIR ANTIBODIES

    EPA Science Inventory

    The advantages of enzyme-immunoassay (EIA) over radioactive assay techniques are mainly convenience in use, in that the labelled immunoreagents are stable for long periods, and the precautions and disposal procedures required for radioisotopes are unnecessary. In addition, the us...

  13. Comparison of salivary cortisol as measured by different immunoassays and tandem mass spectrometry.

    PubMed

    Miller, Robert; Plessow, Franziska; Rauh, Manfred; Gröschl, Michael; Kirschbaum, Clemens

    2013-01-01

    Assessing the amount of bioavailable cortisol in saliva with immunoassays and thus sampling an endocrine marker of hypothalamus-pituitary-adrenal axis activity is of major interest in both research and clinical practice. However, absolute cortisol concentrations obtained with different immunoassays (IAs) are barely comparable precluding direct comparison between studies or individuals whenever cortisol analyses were not based on the same IA. The present technical report aims to solve this problem by evaluating the validity of, as well as agreement between the most commonly used immunoassays in psychoneuroendocrinological research (i.e., IBL, DRG, Salimetrics, DSL, and DELFIA) and a reference method (LC-MS/MS) in a sample of 195 saliva specimen covering the whole range of cortisol concentrations in adults. A structural equation modelling framework is applied to decompose systematic assay variance and estimate cortisol reference values, which are adjusted for measurement error and interference of salivary cortisone. Our findings reveal nonlinear relations between IAs and LC-MS/MS, which are discussed in terms of IA cross-reactivity with saliva matrix components. Finally guidelines for converting cortisol concentrations being obtained by these immunoassays into comparable reference values are proposed by providing conversion functions, a conversion table, and an online conversion tool. PMID:22641005

  14. Detection of E. coli O157:H7 by immunomagnetic separation coupled with fluorescence immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conventional culture-based methods for detection of E. coli O157:H7 in foods and water sources are time-consuming, and results can be ambiguous, requiring further confirmation by biochemical testing and PCR. A rapid immunoassay prior to cultivation to identify presumptive positive sample would save...

  15. Determination of deoxynivalenol in wheat bran and whole-wheat flour by fluorescence polarization immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid and accurate fluorescence polarization (FP) immunoassay has been optimized for the determination of deoxynivalenol (DON) in bran and whole-wheat flour. A preliminary treatment with activated charcoal was used to eliminate the strong matrix effect due to highly colored interfering compounds p...

  16. Multiplexed immunoassays for proteins using magnetic luminescent nanoparticles for internal calibration

    PubMed Central

    Nichkova, Mikaela; Dosev, Dosi; Gee, Shirley J.; Hammock, Bruce D.; Kennedy, Ian M.

    2007-01-01

    Suspension arrays present a promising tool for multiplexed assays in large-scale screening applications. A simple and robust platform for quantitative multiprotein immunoanalysis has been developed with the use of magnetic Co:Nd:Fe2O3/luminescent Eu:Gd2O3 core/shell nanoparticles (MLNPs) as a carrier. The magnetic properties of the MLNPs allow their manipulation by an external magnetic field in the separation and washing steps in the immunoassay. Their optical properties enable the internal calibration of the detection system. The multiplexed sandwich immunoassay involves dual binding events on the surface of the MLNPs functionalized with the capture antibodies. Secondary antibodies labeled with conventional organic dyes (Alexa Fluor) are used as reporters. The amount of the bound secondary antibody is directly proportional to the concentration of the analyte in the sample. In our approach, the fluorescence intensity of the reporter dye is related to the luminescence signal of the MLNPs. In this way, the intrinsic luminescence of the MLNPs serves as an internal standard in the quantitative immunoassay. The concept is demonstrated for a simultaneous immunoassay for three model proteins (human, rabbit and mouse IgGs). The method uses a standard bench plate reader. It can be applied to disease diagnostics and for the detection of biological threats. PMID:17681270

  17. Rapid Detection of Nivalenol and Deoxynivalenol in Wheat Using Surface Plasmon Resonance Immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface plasmon resonance immunoassay using a monoclonal antibody was developed to measure nivalenol (NIV) and deoxynivalenol (DON) contamination in wheat. A DON-immobilized sensor chip having high sensitivity and stability was prepared, and an SPR detection procedure was developed. The competitiv...

  18. The measurement of triclosan in water using a magnetic particle enzyme immunoassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A sensitive magnetic particle-based immunoassay to determine triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) in drinking water and wastewater was developed. Rabbit antiserum was produced by immunizing the rabbit with 6-(5-chloro-2-(2,4-dichlorophenoxy)phenoxy)hexanoic acid-keyhole limpet hemocya...

  19. 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...

  20. Multiplexed immunoassays for proteins using magnetic luminescent nanoparticles for internal calibration.

    PubMed

    Nichkova, Mikaela; Dosev, Dosi; Gee, Shirley J; Hammock, Bruce D; Kennedy, Ian M

    2007-10-01

    Suspension arrays present a promising tool for multiplexed assays in large-scale screening applications. A simple and robust platform for quantitative multiprotein immunoanalysis has been developed with the use of magnetic Co:Nd:Fe(2)O(3)/luminescent Eu:Gd(2)O(3) core/shell nanoparticles (MLNPs) as a carrier. The magnetic properties of the MLNPs allow their manipulation by an external magnetic field in the separation and washing steps in the immunoassay. Their optical properties enable the internal calibration of the detection system. The multiplexed sandwich immunoassay involves dual binding events on the surface of the MLNPs functionalized with the capture antibodies. Secondary antibodies labeled with conventional organic dyes (Alexa Fluor) are used as reporters. The amount of the bound secondary antibody is directly proportional to the concentration of the analyte in the sample. In our approach, the fluorescence intensity of the reporter dye is related to the luminescence signal of the MLNPs. In this way, the intrinsic luminescence of the MLNPs serves as an internal standard in the quantitative immunoassay. The concept is demonstrated for a simultaneous immunoassay for three model proteins (human, rabbit, and mouse IgGs). The method uses a standard bench plate reader. It can be applied to disease diagnostics and to the detection of biological threats. PMID:17681270

  1. DEVELOPMENT OF A FLUORESCENT LATEX IMMUNOASSAY FOR DETECTION OF SPECTINOMYCIN ANTIOBIOTIC

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spectinomycin is an antimicrobial agent used to treat infections caused by Gram negative and positive microorganisms in poultry, swine and non-lactating cattle. There is a need to develop a rapid and sensitive method to detect spectinomycin residues in animal tissues. A latex fluorescent immunoassay...

  2. Development of a nanoparticle-labeled microfluidic immunoassay for detection of pathogenic microorganisms.

    PubMed

    Lin, Frank Y H; Sabri, Mahdi; Alirezaie, Javad; Li, Dongqing; Sherman, Philip M

    2005-03-01

    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. PMID:15753255

  3. An ultrasensitive chemiluminescence immunoassay of chloramphenicol based on gold nanoparticles and magnetic beads.

    PubMed

    Tao, Xiaoqi; Jiang, Haiyang; Yu, Xuezhi; Zhu, Jinghui; Wang, Xia; Wang, Zhanhui; Niu, Lanlan; Wu, Xiaoping; Shen, Jianzhong

    2013-05-01

    A competitive, direct, chemiluminescent immunoassay based on a magnetic beads (MBs) separation and gold nanoparticles (AuNPs) labelling technique to detect chloramphenicol (CAP) has been developed. Horseradish peroxidase (HRP)-labelled anti-CAP monoclonal antibody conjugated with AuNPs and antigen-immobilized MBs were prepared. After optimization parameters of immunocomplex MBs, the IC50 values of chemiluminescence magnetic nanoparticles immunoassay (CL-MBs-nano-immunoassay) were 0.017 µg L(-1) for extract method I and 0.17 µg L(-1) for extract method II. The immunoassay with two extract methods was applied to detect CAP in milk. Comparison of these two extract methods showed that extract method I was advantageous in better sensitivity, in which the sensitivity was 10 times compared to that of extract method II, while extract method II was superior in simple operation, suitable for high throughout screen. The recoveries were 86.7-98.0% (extract method I) and 80.0-103.0% (extract method II), and the coefficients of variation (CVs) were all <15%. The satisfactory recovery with both extract methods and high correlation with traditional ELISA kit in milk system confirmed that the immunomagnetic assay based on AuNPs exhibited promising potential in rapid field screening for trace CAP analysis. PMID:23512826

  4. Magnetic colorimetric immunoassay for human interleukin-6 based on the oxidase activity of ceria spheres.

    PubMed

    Peng, Juan; Guan, Jufang; Yao, Huiqin; Jin, Xiaoyong

    2016-01-01

    A novel magnetic colorimetric immunoassay strategy was designed for sensitive detection of human interleukin-6 (IL-6) using ceria spheres as labels. Ceria spheres showed excellent oxidase activity, which can directly catalyze the oxidation of substrate o-phenylenediamine (OPD) to a stable yellow product, 2,3-diaminophenazine (oxOPD). The absorbance of oxOPD was recorded to reflect the level of IL-6. The relatively mild conditions made the immunoassay strategy more robust, reliable, and easy. A linear relationship between absorbance intensity and the logarithm of IL-6 concentrations was obtained in the range of 0.0001-10 ng mL(-1) with a detection limit of 0.04 pg mL(-1) (S/N = 3). The colorimetric immunoassay exhibited high sensitivity and specificity for the detection of IL-6. This immunoassay has been successfully applied in the detection of IL-6 in serum samples and can be readily extended toward the on-site monitoring of cancer biomarkers in serum samples. PMID:26416691

  5. Magnetic gold nanoparticles in SERS-based sandwich immunoassay for antigen detection by well oriented antibodies.

    PubMed

    Baniukevic, Julija; Hakki Boyaci, Ismail; Goktug Bozkurt, Akif; Tamer, Ugur; Ramanavicius, Arunas; Ramanaviciene, Almira

    2013-05-15

    The aim of the study was to develop an indirect, robust and simple in application method for the detection of bovine leukemia virus antigen gp51. Surface-enhanced Raman scattering (SERS) was applied as detection method. Magnetic gold nanoparticles (MNP-Au) modified by antibodies in oriented or random manner were used for the binding of gp51. The high performance liquid chromatography analysis indicated that the best antibody immobilization and antigen capturing efficiency was achieved using fragmented antibodies obtained after reduction of intact antibodies with dithiothreitol. In order to increase efficiency and sensitivity of immunoassay Raman labels consisting of gold nanorods coated by 5-thio-nitrobenzoic acid layer with covalently bounded antibodies have been constructed. The LOD and LOQ of the proposed immunoassay for antigen gp51 detection were found to be 0.95μgmL(-1) and 3.14μgmL(-1), respectively. This immunoassay was successfully applied for the detection of gp51 in milk samples in a rapid, reliable and selective manner. We believe that the proposed SERS-based immunoassay format can be applied for the detection of other proteins. PMID:23334004

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

    PubMed

    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

    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

  7. IMMUNOASSAY METHODS FOR MEASURING ATRAZINE AND 3,5,6-TRICHLORO-2-PYRIDINOL IN FOODS

    EPA Science Inventory

    This chapter describes the use of enzyme-linked immunosorbent assay (ELISA) methods for the analysis of two potential environmental contaminants in food sample media, atrazine and 3,5,6-trichloro-2-pyridinol (3,5,6-TCP). Two different immunoassay formats are employed: a magnetic...

  8. A 7-plex microbead-based immunoassay for serotyping Shiga toxin-producing Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serotyping of Shiga toxin-producing Escherichia coli (STEC) has been contingent upon the availability of antisera. Here we describe a 7-plex microbead-based immunoassay to simultaneously serotype seven STEC (i.e., belonging to serogroups O26, O45, O103, O111, O121, O145, and O157) by the Luminex xMA...

  9. Visible paper chip immunoassay for rapid determination of bacteria in water distribution system.

    PubMed

    Ma, Sai; Tang, Yanyan; Liu, Jingqing; Wu, Jianmin

    2014-03-01

    Paper chips for immunoassay were patterned by screen printing of polydimethylsiloxane (PDMS) or wax pencil drawing. The methods for paper chip patterning are cheap, convenient, rapid and suitable for most laboratories. The whole time for patterning a paper chip is no more than 10 min. Visible immunoassay for the detection of bacteria (Escherichia coli ) has been realized using the paper chip, on which the antibody for capturing E. Coli was immobilized on the detection zones of the paper chip, while the detection antibody was labeled with gold nanoparticles (AuNPs) as a signal reporter. After an immunological reaction, the AuNPs bound on the paper chip can effectively catalyse the reduction of silver ions during the silver enhancing step, generating a visible result that can be read by naked eyes. The quantitative results can be acquired by scanning the silver stained paper chip with a commercial scanner/or digital camera. The density of E. coli in water samples can be measured after calibrating the gray value of silver stained spots with the logarithmic number of bacteria. The time and reagents consumed on the paper chip immunoassay is much smaller than those of conventional ELISA, while the sensitivity of the paper chip immunoassay is comparable to conventional ELISA. The technology proposed in this work displays a great potential in the in-situ analysis when daily monitoring of water quality are required. PMID:24468352

  10. Highly sensitive immunoassay based on immunogold-silver amplification and inductively coupled plasma mass spectrometric detection.

    PubMed

    Liu, Rui; Liu, Xing; Tang, Yurong; Wu, Li; Hou, Xiandeng; Lv, Yi

    2011-03-15

    In this work, we demonstrated a highly sensitive inductively coupled plasma mass spectrometric (ICPMS) method for the determination of human carcinoembryonic antigen (CEA), which combined the inherent high sensitivity of elemental mass spectrometric measurement with the signal amplification of catalytic silver deposition on immunogold tags. The silver amplification procedure was easy to handle and required cheap reagents, and the sensitivity was greatly enhanced to 60-fold after a 15 min silver amplification procedure. The experimental conditions, including detection of gold and silver by ICPMS, immunoassay parameters, silver amplification parameters, analytical performance, and clinical serum samples analysis, were investigated. The ICPMS Ag signal intensity depends linearly on the logarithm of the concentration of human CEA over the range of 0.07-1000 ng mL(-1) with a limit of detection (LOD, 3σ) of 0.03 ng mL(-1) (i.e., 0.15 pM). The LOD of the proposed method is around 2 orders of magnitude lower than that by the widely used enzyme-linked immunosorbent assay (ELISA) and 1 order of magnitude lower than that by clinical routine chemiluminescence immunoassay (CLIA) or time-resolved fluoroimmunoassay (TRFIA) and conventional ICPMS immunoassay. The present strategy was applied to the determination of human CEA in clinical human serum samples, and the results were in good agreement with those obtained by chemiluminescence immunoassay. PMID:21348438

  11. Production of anti-idiotype antibodies for deoxynivalenol and their evaluation with three immunoassay platforms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassays for deoxynivalenol (DON) that involve the competition for binding to DON-specific antibodies have been widely developed. In such assays, the responses of samples are generally compared to calibration curves generated by using DON in competition with labeled reagents such as enzymatic or...

  12. Fluorescence polarization immunoassays for rapid, accurate and sensitive determination of mycotoxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fluorescence polarization immunoassay (FPIA) is a type of homogeneous assay. For low molecular weight antigens, such as mycotoxins, it is based on the competition between an unlabeled antigen and its fluorescent-labeled derivative (tracer) for an antigen-specific antibody. The antigen content is det...

  13. Application and validation of polybrominated diphenyl ethers immunoassay for environmental and food matrices.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A sensitive magnetic particle enzyme-linked immunoassay (ELISA) was developed to analyze polybrominated diphenyl ethers (PBDEs) in water, milk, fish, chicken and soil samples. The assay is rapid and can be used to analyze fifty samples in about one hour after sample cleanup. The assay has a limit ...

  14. Monoclonal antibody-based broad-specificity immunoassay for monitoring organophosphorus pesticides in environmental water samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The extensive use of organophosphorus pesticides (OPs) in agriculture and domestic settings can result in widespread water contamination. The development of easy-to-use and rapid-screening immunoassay methods in a class-selective manner is a topic of considerable environmental interest. In this wo...

  15. Statistical approaches to developing a multiplex immunoassay for determining human exposure to environmental pathogens.

    EPA Science Inventory

    This paper describes the application and method performance parameters of a Luminex xMAP™ bead-based, multiplex immunoassay for measuring specific antibody responses in saliva samples (n=5438) to antigens of six common waterborne pathogens (Campylobacter jejuni, Helicobacter pylo...

  16. A double-sandwich ELISA for identification of monoclonal antibodies suitable for sandwich immunoassays

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sandwich immunoassay (sIA) is an invaluable technique for concentrating, detecting, and quantifying target antigens. The two critical components required are a capture antibody and a detection antibody, each binding a different epitope on the target antigen. The specific antibodies incorporated...

  17. Silver deposition directed by self-assembled gold nanorods for amplified electrochemical immunoassay.

    PubMed

    Zhang, Hongfang; Ning, Danlei; Ma, Lina; Zheng, Jianbin

    2016-01-01

    A novel electrochemical immunoassay was developed based on the signal amplification strategy of silver deposition directed by gold nanorods (AuNRs), which was in-situ assembled on the sandwich immunocomplex. The superstructure formed by the self-assembly of AuNRs provided abundant active sites for the nucleation of silver nanoparticles. In this pathway, the stripping current of silver was greatly enhanced. Using human immunoglobulin G (HIgG) as a model analyte, the ultrasensitive immunoassay showed a wide linear range of six orders of magnitude from 0.1 fg mL(-1) to 100 pg mL(-1), with the low detection limit down to 0.08 fg mL(-1). The practicality of this electrochemical immunoassay for detection of HIgG in serum was validated with the average recovery of 93.9%. In addition, this enzyme-free immunoassay also has the advantages of acceptable reproducibility and specificity, and thus this immunosensing protocol can be extended to the detection of other low-abundant protein biomarkers. PMID:26703256

  18. AUTOMATED FLOW FLUORESCENT IMMUNOASSAY FOR PART PER TRILLION DETECTION OF THE NEONICOTINOID INSECTICIDE THIAMETHOXAM.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An ultra sensitive automated flow fluorescent immunoassay was developed using the KinExATM 3000 system for quantitative analysis of the neonicotinoid insecticide thiamethoxam. Five monoclonal antibodies were obtained and screened with a competitive ELISA. One monoclonal antibody designated as E6VI ...

  19. ON-SITE MERCURY ANALYSIS OF SOIL AT HAZARDOUS WASTE SITES BY IMMUNOASSAY AND ASV

    EPA Science Inventory

    Two field methods for Hg, immunoassay and anodic stripping voltammetry (ASV), that can provide onsite results for quick decisions at hazardous waste sites were evaluated. Each method was applied to samples from two Superfund sites that contain high levels of Hg; Sulphur Bank Me...

  20. Lateral flow immunoassay for the rapid detection of citrus tristeza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A lateral flow methodology was developed using gold nanoparticles for rapid detection of Citrus tristeza virus (CTV). The test strip was based on a sandwich immunoassay and could be accomplished within 10 minutes. A sample was considered negative for CTV when only the control line appeared; whereas,...

  1. Competitive chemiluminescent anzyme immunoassay for vitamin B12 analysis in human milk.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent discoveries of matrix interferences by haptocorrin (HC) in human milk and serum show that past analyses of vitamin B12 in samples with high HC content might have been inaccurate (Lildballe et al., 2009; Carmel & Agrawal, 2012). We evaluated two competitive enzyme-binding immunoassays for seru...

  2. A commercial rapid optical immunoassay detects Streptococcus agalactiae from aquatic cultures and clinical specimens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The BioStar STREPT B Optical ImmunoAssay (OIA) (BioStar® OIA® Strep B Assay Kit; Biostar Incorporation; Louisville, CO, USA) was used to identify 32 known group B streptococcus (GBS) isolates of fish, dolphin, bovine, and human origin. Thirteen non-GBS isolates from fish and other animals were test...

  3. Pediatric donor cell leukemia after allogeneic hematopoietic stem cell transplantation in AML patient from related donor.

    PubMed

    Bobadilla-Morales, Lucina; Pimentel-Gutiérrez, Helia J; Gallegos-Castorena, Sergio; Paniagua-Padilla, Jenny A; Ortega-de-la-Torre, Citlalli; Sánchez-Zubieta, Fernando; Silva-Cruz, Rocio; Corona-Rivera, Jorge R; Zepeda-Moreno, Abraham; González-Ramella, Oscar; Corona-Rivera, Alfredo

    2015-01-01

    Here we present a male patient with acute myeloid leukemia (AML) initially diagnosed as M5 and with karyotype 46,XY. After induction therapy, he underwent a HLA-matched allogeneic hematopoietic stem cell transplantation, and six years later he relapsed as AML M1 with an abnormal karyotype //47,XX,+10[2]/47,XX,+11[3]/48,XX,+10,+11[2]/46,XX[13]. Based on this, we tested the possibility of donor cell origin by FISH and molecular STR analysis. We found no evidence of Y chromosome presence by FISH and STR analysis consistent with the success of the allogeneic hematopoietic stem cell transplantation from the female donor. FISH studies confirmed trisomies and no evidence of MLL translocation either p53 or ATM deletion. Additionally 28 fusion common leukemia transcripts were evaluated by multiplex reverse transcriptase-polymerase chain reaction assay and were not rearranged. STR analysis showed a complete donor chimerism. Thus, donor cell leukemia (DCL) was concluded, being essential the use of cytological and molecular approaches. Pediatric DCL is uncommon, our patient seems to be the sixth case and additionally it presented a late donor cell leukemia appearance. Different extrinsic and intrinsic mechanisms have been considered to explain this uncommon finding as well as the implications to the patient. PMID:25674158

  4. Improved Outcome of Alternative Donor Transplantations in Patients with Myelofibrosis: From Unrelated to Haploidentical Family Donors.

    PubMed

    Bregante, Stefania; Dominietto, Alida; Ghiso, Anna; Raiola, Anna Maria; Gualandi, Francesca; Varaldo, Riccardo; Di Grazia, Carmen; Lamparelli, Teresa; Luchetti, Silvia; Geroldi, Simona; Casarino, Lucia; Pozzi, Sarah; Tedone, Elisabetta; Van Lint, Maria Teresa; Galaverna, Federica; Barosi, Giovanni; Bacigalupo, Andrea

    2016-02-01

    This is a retrospective analysis of 95 patients with myelofibrosis who were allografted between 2001 and 2014. The aims of the study were to assess whether the outcome of alternative donor grafts has improved with time and how this compares with the outcome of identical sibling grafts. Patients were studied in 2 time intervals: 2000 to 2010 (n = 58) and 2011 to 2014 (n = 37). The Dynamic International Prognostic Scoring System score was comparable in the 2 time periods, but differences in the most recent group included older age (58 versus 53 years, P = .004), more family haploidentical donors (54% versus 5%, P < .0001), and the introduction of the thiotepa-fludarabine-busulfan conditioning regimen (70% of patients versus 2%, P < .0001). Acute and chronic graft-versus-host disease were comparable in the 2 time periods. The 3-year transplantation-related mortality (TRM) in the 2011 to 2014 period versus the 2000 to 2010 period is 16% versus 32% (P = .10), the relapse rate 16% versus 40% (P = .06), and actuarial survival 70% versus 39% (P = .08). Improved survival was most pronounced in alternative donor grafts (69% versus 21%, P = .02), compared with matched sibling grafts (72% versus 45%, P = .40). In conclusion, the outcome of allografts in patients with myelofibrosis has improved in recent years because of a reduction of both TRM and relapse. Improvement is most significant in alternative donor transplantations, with modifications in donor type and conditioning regimen. PMID:26456259

  5. Living donor renal transplantation with incidental renal cell carcinoma from donor allograft.

    PubMed

    Lugo-Baruqui, Jose A; Guerra, Giselle; Chen, Linda; Burke, George W; Gaite, Judith A; Ciancio, Gaetano

    2015-09-01

    To report our series of cases with living donor kidney transplant by laparoscopic nephrectomy with incidental renal cell carcinomas (RCC) at the time of transplant. We performed a search of cases of renal allografts from living donors with incidental tumors which were confirmed as RCC in final pathology. The graft nephrectomy was performed via hand-assisted laparoscopic procedure. All cases underwent partial nephrectomy of the tumor during the back-table preparation of the graft and sent for pathological analysis. We performed 435 living donor kidney transplants at our Institution and identified four cases consistent with the diagnosis of RCC. Two of them were clear cell type, one papillary and one multilocular RCC. All the tumors presented at stage I of TNM classification. After a median follow-up of 36 months, three patients remain free of dialysis with good allograft function. One noncompliant patient presented with a glomerular filtration rate (GFr) below 15 ml/min after a BK viral infection. At the end of follow-up period, all patients had remained free of tumor. Donors with suspicious renal masses might be accepted for living donation. Partial nephrectomy before transplantation could offer a cure for the disease without risks for the recipient with therapeutic benefit for the donor. PMID:25898787

  6. Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays: applications, fundamentals, and optimization

    SciTech Connect

    Jeremy Daniel Driskell

    2006-08-09

    Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the mechanism responsible for surface enhancement. Approaches to reduce assay times are also investigated. Implementing the knowledge gained from these studies will lead to a more sensitive immunoassay requiring less time than its predecessors. This dissertation is organized into six sections. The first section includes a literature review of the previous work that led to this dissertation. A general overview of the different approaches to immunoassays is given, outlining the strengths and weaknesses of each. Included is a detailed review of binding kinetics, which is central for decreasing assay times. Next, the theoretical underpinnings of SERS is reviewed at its current level of understanding. Past work has argued that surface plasmon resonance (SPR) of the enhancing substrate influences the SERS signal; therefore, the SPR of the extrinsic Raman labels (ERLs) utilized in our SERS-based immunoassay is discussed. Four original research chapters follow the Introduction, each presented as separate manuscripts. Chapter 2 modifies a SERS-based immunoassay previously developed in our group, extending it to the low-level detection of viral pathogens and demonstrating its versatility in terms of analyte type, Chapter 3 investigates the influence of ERL size, material composition, and separation distance between the ERLs and capture substrate on the SERS signal. This chapter links SPR with SERS enhancement factors and is consistent with many of the results from theoretical treatments of SPR and SERS. Chapter 4 introduces a novel method of reducing sample incubation time via capture substrate rotation. Moreover, this work led to a method of virus quantification without the use of standards. Chapter 5 extends the methodology developed in Chapter 4 to both the antigen and ERL labeling step to perform assays with improved analytical performance in less time than can be accomplished in diffusion controlled assays. This dissertation concludes with a general summary and speculates on the future of this exciting approach to carrying out immunoassays.

  7. Computer applications in the search for unrelated stem cell donors.

    PubMed

    Müller, Carlheinz R

    2002-08-01

    The majority of patients which are eligible for a blood stem cell transplantation from an allogeneic donor do not have a suitable related donor so that an efficient unrelated donor search is a prerequisite for this treatment. Currently, there are over 7 million volunteer donors in the files of 50 registries in the world and in most countries the majority of transplants are performed from a foreign donor. Evidently, computer and communication technology must play a crucial role in the complex donor search process on the national and international level. This article describes the structural elements of the donor search process and discusses major systematic and technical issues to be addressed in the development and evolution of the supporting telematic systems. The theoretical considerations are complemented by a concise overview over the current state of the art which is given by describing the scope, relevance, interconnection and technical background of three major national and international computer appliances: The German Marrow Donor Information System (GERMIS) and the European Marrow Donor Information System (EMDIS) are interoperable business-to-business e-commerce systems and Bone Marrow Donors World Wide (BMDW) is the basic international donor information desk on the web. PMID:12216954

  8. 21 CFR 1271.50 - How do I determine whether a donor is eligible?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.50 How do I... document the eligibility of a cell or tissue donor. (b) Eligible donor. A donor is eligible under...

  9. 21 CFR 1271.50 - How do I determine whether a donor is eligible?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.50 How do I... document the eligibility of a cell or tissue donor. (b) Eligible donor. A donor is eligible under...

  10. 21 CFR 1271.50 - How do I determine whether a donor is eligible?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HUMAN CELLS, TISSUES, AND CELLULAR AND TISSUE-BASED PRODUCTS Donor Eligibility § 1271.50 How do I... document the eligibility of a cell or tissue donor. (b) Eligible donor. A donor is eligible under...

  11. Transplantation and differentiation of donor cells in the cloned pigs

    SciTech Connect

    Shimada, Arata; Tomii, Ryo; Kano, Koichiro; Nagashima, Hiroshi . E-mail: hnagas@isc.meiji.ac.jp

    2006-06-02

    The application of nuclear transfer technology is an interesting approach to investigate stem and progenitor cell transplantation therapy. If stem cells are used as a nuclear donor, donor cells can engraft into cloned animals without histocompatible problems. However, it is still uncertain whether donor cells can engraft to cloned animal and differentiate in vivo. To address this problem, we transplanted donor cells to dermal tissues of cloned pigs developed by using preadipocytes as donor cells. Preadipocytes are adipocytic progenitor which can differentiate to mature adipocytes in vitro. We showed that the donor preadipocytes were successfully transplanted into the cloned pigs without immune rejection and they differentiated into mature adipocytes in vivo 3 weeks after transplantation. In contrast, allogenic control preadipocytes, which can differentiate in vitro, did not differentiate in vivo. These results indicate that donor progenitor cells can differentiate in cloned animal.

  12. Overextended Criteria Donors: Experience of an Italian Transplantation Center.

    PubMed

    Nure, E; Lirosi, M C; Frongillo, F; Bianco, G; Silvestrini, N; Fiorillo, C; Sganga, G; Agnes, S

    2015-09-01

    The increasing gap between the number of patients who could benefit from liver transplantation and the number of available donors has fueled efforts to maximize the donor pool using marginal grafts that usually were discarded for transplantation. This study included data of all patients who received decreased donor liver grafts between January 2004 and January 2013 (n = 218) with the use of a prospectively collected database. Patients with acute liver failure, retransplantation, pediatric transplantation, and split liver transplantation were excluded. Donors were classified as standard donor (SD), extended criteria donor (ECD), and overextended criteria donor (OECD). The primary endpoints of the study were early allograft primary dysfunction (PDF), primary nonfunction (PNF), and patient survival (PS), whereas incidence of major postoperative complications was the secondary endpoint. In our series we demonstrated that OECD have similar outcome in terms of survival and incidence of complication after liver transplantation as ideal grafts. PMID:26361653

  13. Comparisons of Immunoassay and Mass Spectrometry Measurements of Serum Estradiol Levels and Their Influence on Clinical Association Studies in Men

    PubMed Central

    Nilsson, Maria E.; Tivesten, Åsa; Ryberg, Henrik; Mellström, Dan; Karlsson, Magnus K.; Ljunggren, Östen; Labrie, Fernand; Orwoll, Eric S.; Lee, David M.; Pye, Stephen R.; O'Neill, Terence W.; Finn, Joseph D.; Adams, Judith E.; Ward, Kate A.; Boonen, Steven; Bartfai, Gyorgy; Casanueva, Felipe F.; Forti, Gianni; Giwercman, Aleksander; Han, Thang S.; Huhtaniemi, Ilpo T.; Kula, Krzysztof; Lean, Michael E. J.; Pendleton, Neil; Punab, Margus; Vanderschueren, Dirk; Wu, Frederick C. W.; Vandenput, Liesbeth

    2013-01-01

    Context: Immunoassay-based techniques, routinely used to measure serum estradiol (E2), are known to have reduced specificity, especially at lower concentrations, when compared with the gold standard technique of mass spectrometry (MS). Different measurement techniques may be responsible for the conflicting results of associations between serum E2 and clinical phenotypes in men. Objective: Our objective was to compare immunoassay and MS measurements of E2 levels in men and evaluate associations with clinical phenotypes. Design and Setting: Middle-aged and older male subjects participating in the population-based Osteoporotic Fractures in Men (MrOS) Sweden study (n = 2599), MrOS US (n = 688), and the European Male Aging Study (n = 2908) were included. Main Outcome Measures: Immunoassay and MS measurements of serum E2 were compared and related to bone mineral density (BMD; measured by dual energy x-ray absorptiometry) and ankle-brachial index. Results: Within each cohort, serum E2 levels obtained by immunoassay and MS correlated moderately (Spearman rank correlation coefficient rS 0.53–0.76). Serum C-reactive protein (CRP) levels associated significantly (albeit to a low extent, rS = 0.29) with immunoassay E2 but not with MS E2 levels. Similar associations of immunoassay E2 and MS E2 were seen with lumbar spine and total hip BMD, independent of serum CRP. However, immunoassay E2, but not MS E2, associated inversely with ankle-brachial index, and this correlation was lost after adjustment for CRP. Conclusions: Our findings suggest interference in the immunoassay E2 analyses, possibly by CRP or a CRP-associated factor. Although associations with BMD remain unaffected, this might imply for a reevaluation of previous association studies between immunoassay E2 levels and inflammation-related outcomes. PMID:23633197

  14. Multifunctional reduced graphene oxide trigged chemiluminescence resonance energy transfer: Novel signal amplification strategy for photoelectrochemical immunoassay of squamous cell carcinoma antigen.

    PubMed

    Zhang, Yan; Sun, Guoqiang; Yang, Hongmei; Yu, Jinghua; Yan, Mei; Song, Xianrang

    2016-05-15

    Herein, a photoelectrochemical (PEC) immunoassay is constructed for squamous cell carcinoma antigen (SCCA) detection using zinc oxide nanoflower-bismuth sulfide (Bi2S3) composites as photoactive materials and reduced graphene oxide (rGO) as signal labels. Horseradish peroxidase is used to block sites against nonspecific binding, and then participated in luminol-based chemiluminescence (CL) system. The induced CL emission is acted as an inner light source to excite photoactive materials, simplifying the instrument. A novel signal amplification strategy is stem from rGO because of the rGO acts as an energy acceptor, while luminol serves as a donor to rGO, triggering the CL resonance energy transfer phenomenon between luminol and rGO. Thus, the efficient CL emission to photoactive materials decreases. Furthermore, the signal amplification caused by rGO labeled signal antibodies is related to photogenerated electron-hole pairs: perfect matching of energy levels between rGO and Bi2S3 makes rGO a sink to capture photogenerated electrons from Bi2S3; the increased steric hindrance hinders the electron donor to the surface of Bi2S3 for reaction with the photogenerated holes. On the basis of the novel signal amplification strategy, the proposed immunosensor exhibits excellent analytical performance for PEC detection of SCCA, ranging from 0.8 pg mL(-1) to 80 ng mL(-1) with a low detection limit of 0.21 pg mL(-1). Meanwhile, the designed signal amplification strategy provides a general format for future development of PEC assays. PMID:26686924

  15. Human Merkel cell polyomavirus infection II. MCV is a common human infection that can be detected by conformational capsid epitope immunoassays.

    PubMed

    Tolstov, Yanis L; Pastrana, Diana V; Feng, Huichen; Becker, Jürgen C; Jenkins, Frank J; Moschos, Stergios; Chang, Yuan; Buck, Christopher B; Moore, Patrick S

    2009-09-15

    Merkel cell polyomavirus (MCV) is a newly-discovered human tumor virus found in approximately 80% of Merkel cell carcinoma (MCC). The rate of MCV infection among persons without MCC is unknown. We developed a MCV virus-like particle (VLP) enzyme-linked immunoassay (EIA) that does not cross-react with human BK or murine polyomaviruses. Peptide mapping of the MCV VP1 gene and immunoblotting with denatured MCV VLP are less sensitive than the MCV EIA in detecting MCV antibodies suggesting antibody reactivity in this assay primarily targets conformational but not linear epitopes. Among MCC patients, all 21 (100%) patients tested with MCV-positive tumors had high serum MCV IgG but not high MCV IgM levels. Only 3 of 6 (50%) MCC patients with MCV-negative tumors were positive for MCV antibodies. Sera from most adults, including 107 of 166 (64%) blood donors, 63 of 100 (63%) commercial donors and 37 of 50 (74%) systemic lupus erythematosus patients, show evidence for prior MCV exposure. Age-specific MCV prevalence was determined by examining a cross-sectional distribution of 150 Langerhans cell histiocytosis (an unrelated neoplasm) patient sera. MCV prevalence increases from 50% among children age 15 years or younger to 80% among persons older than 50 years. We did not find evidence for vertical transmission among infants. Although past exposure to MCV is common among all adult groups, MCC patients have a markedly elevated MCV IgG response compared with control patients. Our study demonstrates that MCV is a widespread but previously unrecognized human infection. PMID:19499548

  16. Functionalized gold nanoclusters as fluorescent labels for immunoassays: Application to human serum immunoglobulin E determination.

    PubMed

    Alonso, María Cruz; Trapiella-Alfonso, Laura; Fernández, José M Costa; Pereiro, Rosario; Sanz-Medel, Alfredo

    2016-03-15

    A quantitative immunoassay for the determination of immunoglobulin E (IgE) in human serum using gold nanoclusters (AuNCs) as fluorescent label was developed. Water soluble AuNCs were synthesized using lipoic acid and then thoroughly characterized. The obtained AuNCs have a particle size of 2.7±0.1nm and maximum fluorescence emission at 710nm. The synthesized AuNCs showed very good stability of the fluorescent signal with light exposure and at neutral and slightly basic media. A covalent bioconjugation of these AuNCs with the desired antibody was carried out by the carbodiimide reaction. After due optimization of such bioconjugation reaction, a molar ratio 1:3 (antibody:AuNCs) was selected. The bioconjugate maintained an intense luminescence emission, slightly red-shifted as compared to the free AuNCs. Two typical immunoassay configurations, competitive and sandwich, were assayed and their performance for IgE determination critically compared. After the different immunoassay steps were accomplished, the fluorescence emission of the bioconjugate was measured. While the sandwich format provided a detection limit (DL) of 10ng/mL and a linear range between 25 and 565ng/mL of IgE, the competitive format revealed a DL of 0.2ng/mL with a linear range between 0.3 and 7.1ng/mL The applicability of the more sensitive competitive fluorescent immunoassay was assessed by successful analysis of the IgE in human serum and comparison of results with those from a commercial kit. The main advantages of the proposed AuNCs-based fluorimetric method include a low DL and a simple immunoassay protocol involving few reagents. PMID:26547433

  17. A highly efficient bead extraction technique with low bead number for digital microfluidic immunoassay.

    PubMed

    Huang, Cheng-Yeh; Tsai, Po-Yen; Lee, I-Chin; Hsu, Hsin-Yun; Huang, Hong-Yuan; Fan, Shih-Kang; Yao, Da-Jeng; Liu, Cheng-Hsien; Hsu, Wensyang

    2016-01-01

    Here, we describe a technique to manipulate a low number of beads to achieve high washing efficiency with zero bead loss in the washing process of a digital microfluidic (DMF) immunoassay. Previously, two magnetic bead extraction methods were reported in the DMF platform: (1) single-side electrowetting method and (2) double-side electrowetting method. The first approach could provide high washing efficiency, but it required a large number of beads. The second approach could reduce the required number of beads, but it was inefficient where multiple washes were required. More importantly, bead loss during the washing process was unavoidable in both methods. Here, an improved double-side electrowetting method is proposed for bead extraction by utilizing a series of unequal electrodes. It is shown that, with proper electrode size ratio, only one wash step is required to achieve 98% washing rate without any bead loss at bead number less than 100 in a droplet. It allows using only about 25 magnetic beads in DMF immunoassay to increase the number of captured analytes on each bead effectively. In our human soluble tumor necrosis factor receptor I (sTNF-RI) model immunoassay, the experimental results show that, comparing to our previous results without using the proposed bead extraction technique, the immunoassay with low bead number significantly enhances the fluorescence signal to provide a better limit of detection (3.14 pg/ml) with smaller reagent volumes (200 nl) and shorter analysis time (<1 h). This improved bead extraction technique not only can be used in the DMF immunoassay but also has great potential to be used in any other bead-based DMF systems for different applications. PMID:26858807

  18. Picosecond optical switching based on biphotonic excitation of an electron donor-accepter-donor molecule

    SciTech Connect

    O'Neil, M.P.; Niemczyk, M.P.; Svec, W.A.; Gosztola, D.; Gaines, G.L. III; Wasielewski, M.R. )

    1992-07-03

    An electron donor-acceptor-donor molecule consisting of two porphyrin donors rigidly attached to the two-electron acceptor N,N{prime}-diphenyl-3,4,9,10-perylenebis (dicarboximide) acts as a light intensity-dependent molecular switch on a picosecond time scale. Excitation of the porphyrins within this molecule with subpicosecond laser pulses results in single or double reduction of the acceptor depending on the light intensity. The singly and doubly reduced electron acceptors absorb light strongly at 713 and 546 nanometers, respectively. Because these absorption changes are produced solely by electron transfers, this molecular switch effectively has no moving parts and switches significantly faster than photochromic molecules that must undergo changes in molecular structure.

  19. Discontinuation of Living Donor Liver Transplantation due to Donor's Intraoperative Latex-Induced Anaphylactic Shock

    PubMed Central

    Shinoda, Masahiro; Tanabe, Minoru; Nagao, Keisuke; Kitago, Minoru; Fujisaki, Hiroto; Odaira, Masanori; Kawachi, Shigeyuki; Itano, Osamu; Obara, Hideaki; Matsubara, Kentaro; Shimojima, Naoki; Fuchimoto, Yasushi; Hoshino, Ken; Amagai, Masayuki; Kuroda, Tatsuo; Kitagawa, Yuko

    2012-01-01

    We report on a 33-year-old female liver donor candidate who developed intraoperative latex-induced anaphylactic shock during surgery for living donor transplantation. She was the mother of the organ recipient, who was a 9-year-old boy with biliary atresia. We planned extended lateral segmentectomy for her. Although we dissected the ligament around the left lobe, the systolic blood pressure suddenly dropped and her body became flushed and warm. We administered transfusion and an ephedrine injection to recover the blood pressure. Because she recovered after the treatment, we restarted the procedure. However, she went into shock again within a few minutes. We decided to discontinue the operation. Postoperative blood tests revealed an increase in IgE-RAST and basophil activation, suggesting that the anaphylactic shock was induced by latex. Because latex allergy has become a public health problem, this allergy should be kept in mind as a potential donor operation risk. PMID:23294079

  20. Simulation of the kinetics of phosphorescence buildup of energy donor molecules in matrix-isolated donor-acceptor pairs

    NASA Astrophysics Data System (ADS)

    Zhdanova, N. V.; Deryabin, M. I.; Tishchenko, A. B.

    2015-10-01

    A mathematical model is proposed for describing the kinetics of accumulation of donor molecules in the triplet state for matrix-isolated donor-acceptor pairs. Using this model, computer simulation of the kinetics of accumulation of triplet excitations and phosphorescence buildup of the donor is performed. It is found that for certain relations between the rate constants of transitions for the donor and acceptor of the triplet excitation energy, the kinetics of phosphorescence buildup and the quantum yield of the donor phosphorescence depend on the excitation power.

  1. Thermoelectric Performance of Donor-Acceptor-Donor Conjugated Polymers Based on Benzothiadiazole Derivatives

    NASA Astrophysics Data System (ADS)

    Ming, Shouli; Zhen, Shijie; Lin, Kaiwen; Zhao, Li; Xu, Jingkun; Lu, Baoyang; Wang, Liangying; Xiong, Jinhua; Zhu, Zhengzhou

    2015-06-01

    Donor-acceptor-donor conjugated polymers are superior to other thermoelectric organic materials because it is much easier to modify their structure to reduce the bandgap between the conduction and valence bands, which is desirable for thermoelectric materials with high Seebeck coefficients. Despite this, studies of the thermoelectric performance of donor-acceptor-donor conjugated polymers are rare. In this study, four low-bandgap donor-acceptor-donor conjugated polymers, poly(4,7-bis(2,3-dihydrothieno[3,4- b][1,4] dioxin-5-yl)benzo[ c][1,2,5]thiadiazole) (PEBTE), poly(4,7-bis(2,3-dihydrothieno[3,4- b][1,4]dioxin-5-yl)benzo[ c][1,2,5]selenadiazole) (PEBSeE), poly (4,7-bis(2,3-dihydrothieno[3,4- b][1,4]dioxin-5-yl)-[1,2,5]thiadiazolo [3,4- c] pyridine) (PEPTE), and poly(4,7-bis(2,3-dihydrothieno[3,4- b][1,4]dioxin-5-yl)-[1,2,5]selenadiazolo[3,4- c]pyridine) (PEPSeE), were deposited by electrochemical polymerization of 4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)benzo[c][1,2,5]thiadiazole (EBTE), 4,7-bis(2,3-dihydro-thieno[3,4-b][1,4] dioxin-5-yl)benzo[c][1,2,5]selenadiazole (EBSeE), 4,7-bis(2,3-dihydrothieno [3,4-b][1,4]dioxin-5-yl)-[1,2,5]thiadiazolo[3,4-c] pyridine (EPTE) and 4,7-bis (2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-[1,2,5] selenadiazolo[3,4-c]pyridine (EPSeE), respectively and their thermoelectric performance was investi- gated. Compared with polyselenophenes, PEBTE and PEBSeE in pressed pellets had higher electrical conductivity (10-1-101 S cm-1) but lower Seebeck coefficient (14.0 μV K-1) at room temperature. Future work may focus on treatment of these donor-acceptor-donor polymers to improve their electrical conductivity and Seebeck coefficient, and further investigation of their thermoelectric performance.

  2. [Non-heart-beating donors are ineligible].

    PubMed

    Heide, W

    2016-02-01

    The death of the donor is a mandatory prerequisite for organ transplantation (dead donor rule) worldwide. It is a medical, legal and ethical consensus to accept the concept of brain death, as first proposed in 1968 by the ad hoc committee of the Harvard Medical School, as a certain criterion of death. In isolated cases where the diagnosis of brain death was claimed to be wrong, it could be demonstrated that the diagnostic procedure for brain death had not been correctly performed. In March 2014 a joint statement by the German neuromedical societies emphasized that 1) the diagnosis of brain death is one of the safest diagnoses in medicine if performed according to accepted medical standards and criteria and 2) the concept of non-heart-beating donors (NHBD, i. e. organ donation after an arbitrarily defined duration of circulatory and cardiac arrest) practiced in some European countries must be absolutely rejected because it implicates a high risk of diagnostic error. According to the current literature it is unclear at what time cardiac and circulatory arrest is irreversible and leads to irreversible cessation of all functions of the entire brain including the brainstem, even though clinical signs of cessation of brain functions are always found after 10 min. Furthermore, is it often an arbitrary decision to exactly define the duration of cardiac arrest if continuous echocardiographic monitoring has not been carried out from the very beginning. Last but not least there are ethical concerns against the concept of NHBD because it might influence therapeutic efforts to resuscitate a patient with cardiac arrest. Therefore, the German Medical Council (BÄK) has repeatedly rejected the concept of NHBD for organ transplantation since 1995. PMID:26830897

  3. Polymerization Initiated by Organic Electron Donors.

    PubMed

    Broggi, Julie; Rollet, Marion; Clément, Jean-Louis; Canard, Gabriel; Terme, Thierry; Gigmes, Didier; Vanelle, Patrice

    2016-05-10

    Polymerization reactions with organic electron donors (OED) as initiators are presented herein. The metal-free polymerization of various activated alkene and cyclic ester monomers was performed in short reaction times, under mild conditions, with small amounts of organic reducing agents, and without the need for co-initiators or activation by photochemical, electrochemical, or other methods. Hence, OED initiators enabled the development of an efficient, rapid, room-temperature process that meets the technical standards expected for industrial processes, such as energy savings, cost-effectiveness and safety. Mechanistic investigations support an electron-transfer initiation pathway that leads to the reduction of the monomer. PMID:27061743

  4. Artificial donor insemination frozen versus fresh semen.

    PubMed

    Leeton, J; Selwood, T; Trounson, A; Wood, C

    1980-11-01

    The results of artificial insemination by fresh and frozen donor semen (A.I.D.) are reported. Life table conception results were 66.3 +/- 3.8 after 6 months for the fresh semen group. Similar results for 2 consecutive programmes of A.I.D. of frozen semen were 44.0 +/- 4.6 and 64.2 +/- 3.4, respectively. The latter group's cumulative pregnancy rate is high and probably reflects improvement in both sperm preservation and insemination techniques. Using improved freezing techniques, the results of A.I.D. with frozen semen are equal to those with fresh semen. PMID:6940563

  5. Potential donor segregation to promote blood donation.

    PubMed

    Martn-Santana, Josefa D; Beerli-Palacio, Asuncin

    2008-04-01

    This work is set in the field of social marketing and more specifically in the context of blood donation. Its principal objective focuses on segregating potential donors by using the inhibitors or barriers to a blood donation behaviour as criteria. Moreover, an analysis of the predisposition to donate blood, the intrinsic and extrinsic motivations for donating blood, and the incentives that may stimulate their donation conduct was conducted for each of the four identified groups. The results reveal that the four segments differ significantly in their predisposition to donate, in their motivations and in the incentives that encourage them to donate blood. PMID:18343199

  6. 75 FR 58400 - Donor Management Research: Improvements in Clinical Management of Deceased Organ Donors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ...The Health Resources and Services Administration (HRSA), Division of Transplantation, is soliciting input, feedback, and suggestions from researchers and interested parties within the organ donation and transplant community regarding guidance for a possible grant or contract that focuses on improvements in clinical management of deceased organ donors. Given the continued imbalance between the......

  7. The Willed Body Donor Interview Project: Medical Student and Donor Expectations

    ERIC Educational Resources Information Center

    Bohl, Michael; Holman, Alexis; Mueller, Dean A.; Gruppen, Larry D.; Hildebrandt, Sabine

    2013-01-01

    The Anatomical Donations Program at the University of Michigan Medical School (UMMS) has begun a multiphase project wherein interviews of donors will be recorded and later shown to medical students who participate in the anatomical dissection course. The first phase of this project included surveys of both current UMMS medical students and donors…

  8. Early immunosuppression withdrawal after living donor liver transplantation and donor stem cell infusion.

    PubMed

    Donckier, Vincent; Troisi, Roberto; Le Moine, Alain; Toungouz, Michel; Ricciardi, Salvatore; Colle, Isabelle; Van Vlierberghe, Hans; Craciun, Ligia; Libin, Myriam; Praet, Marleen; Noens, Lucien; Stordeur, Patrick; Andrien, Marc; Lambermont, Micheline; Gelin, Michel; Bourgeois, Nadine; Adler, Michael; de Hemptinne, Bernard; Goldman, Michel

    2006-10-01

    Long-term results of organ transplantation are still limited by serious side effects of immunosuppressive drugs. A major issue, therefore, is to elaborate novel therapeutic protocols allowing withdrawal or minimization of immunosuppressive therapy after transplantation. We report on 3 patients prospectively enrolled in an original protocol designed to promote graft acceptance in living donor liver transplantation, using posttransplant conditioning with high doses of antithymocyte globulin followed by injection of donor-derived stem cells. In 2 patients, early immunosuppression withdrawal was possible, without subsequent graft deterioration. In these 2 cases, in vitro studies showed indices of immunological tolerance as assessed by specific hyporesponsiveness to donor alloantigens in mixed lymphocytes culture. In the third patient, acute rejection rapidly occurred after discontinuation of immunosuppression, and minimal immunosuppression has to be maintained during long-term follow-up. In this case, a clearly distinct immunoreactive profile was observed as compared to tolerant patients, as no specific modulation of the antidonor response was observed in vitro. Of note, no macrochimerism could be detected in any of the 3 patients during the follow-up. In conclusion, these clinical observations demonstrated that, despite the absence of macrochimerism, donor stem cells infusion combined with recipient conditioning may allow early immunosuppression withdrawal or minimization after liver transplantation. PMID:17004249

  9. Counted Sb donors in Si quantum dots

    NASA Astrophysics Data System (ADS)

    Singh, Meenakshi; Pacheco, Jose; Bielejec, Edward; Perry, Daniel; Ten Eyck, Gregory; Bishop, Nathaniel; Wendt, Joel; Luhman, Dwight; Carroll, Malcolm; Lilly, Michael

    2015-03-01

    Deterministic control over the location and number of donors is critical for donor spin qubits in semiconductor based quantum computing. We have developed techniques using a focused ion beam and a diode detector integrated next to a silicon MOS single electron transistor to gain such control. With the diode detector operating in linear mode, the numbers of ions implanted have been counted and single ion implants have been detected. Poisson statistics in the number of ions implanted have been observed. Transport measurements performed on samples with counted number of implants have been performed and regular coulomb blockade and charge offsets observed. The capacitances to various gates are found to be in agreement with QCAD simulations for an electrostatically defined dot. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  10. Therapeutic donor insemination with frozen semen.

    PubMed Central

    Scott, S G; Mortimer, D; Taylor, P J; Leader, A; Pattinson, H A

    1990-01-01

    Although it is now accepted that cryopreserved semen must, on ethical and medicolegal grounds, be used for donor insemination many clinicians still believe that it has an unacceptably reduced fecundability rate as compared with fresh semen. We studied the outcome of 81 recipients who started therapeutic donor insemination (TDI) treatment during 1986 in a program that used exclusively cryopreserved semen; 55 had never undergone TDI and were receiving the first series (six cycles), 6 were receiving the second series (also six cycles), and 20 had achieved pregnancy through TDI previously and were starting the treatment again. Insemination with semen stored in 0.5-ml French straws was performed daily during the periovulatory period while the modified Insler score was 10 or greater out of 15. A total of 42 (52%) of the recipients became pregnant within six TDI cycles; 4 (10%) had a spontaneous abortion. An average of 4.8 straws were used per cycle among those who became pregnant and 5.1 per cycle among those who did not. On average 2.6 cycles were required to achieve pregnancy. The overall fecundability rate was 14.6%. We conclude that a TDI program involving exclusively frozen semen can be operated with a success rate comparable to rates achieved with fresh semen if a simple, established cryopreservation method and an uncomplicated clinical management protocol are used. PMID:2383847

  11. DEMONSTRATION BULLETIN: PCP IMMUNOASSAY TECHNOLOGIES - PENTA RISC BY ENSYS INC., PENTA RAPID BY OHMICRON CORP., ENVIROGARD BY MILLIPORE

    EPA Science Inventory

    The objectives of this demonstration were to test these field screening technologies for accuracy and precision in detecting Pentachlorophenol (PCP) levels in soil and water by comparing their results with those of a confirmatory laboratory. The three immunoassay technologies ...

  12. Hydrophilic, bright CuInS2 quantum dots as Cd-free fluorescent labels in quantitative immunoassay.

    PubMed

    Speranskaya, Elena S; Beloglazova, Natalia V; Abé, Sofie; Aubert, Tangi; Smet, Philippe F; Poelman, Dirk; Goryacheva, Irina Y; De Saeger, Sarah; Hens, Zeger

    2014-07-01

    We report on the synthesis of core-shell CuInS2/ZnS quantum dots (QDs) in organic solution, their encapsulation with a PEG-containing amphiphilic polymer, and the application of the resulting water-soluble QDs as fluorescent label in quantitative immunoassay. By optimizing the methods for core synthesis and shell growth, CuInS2/ZnS QDs were obtained with a quantum yield of 50% on average after hydrophilization. After conjugation with an aflatoxin B1-protein derivative, the obtained QDs were used as fluorescent labels in microplate immunoassay for the quantitative determination of the mycotoxin aflatoxin B1. QDs-based immunoassay showed higher sensitivity compared to enzyme-based immunoassay. PMID:24892375

  13. In vitro conditions modify immunoassayability of bovine pituitary prolactin and growth hormone: insights into their secretory granule storage forms

    SciTech Connect

    Lorenson, M.Y.

    1985-04-01

    The amount of immunoassayable intracellular bovine (b) PRL and GH varies depending on treatment conditions. The present studies were designed to characterize the mechanisms involved and to compare immunoassayability of both hormones under similar conditions. Pituitary homogenate and secretory granule hormones displayed both time- and temperature-dependent increases when incubated at pH 10.5 with reduced glutathione. Changes in immunoassayability seem to reflect conversion from poorly immunoactive tissue hormone oligomers to monomeric hormone. The data indicate that oligomeric bPRL is stabilized primarily by intermolecular disulfide bonds, although it is also susceptible to urea, SDS, and EDTA; granule thiols may also influence the conversion to monomer. The storage form of bGH appears to be stabilized differently. Maneuvers demonstrated in these studies to influence immunoassayability correlate very well with their previously established effects on hormone release and secretion, strengthening the likelihood that a functional link exists between assayability and secretion.

  14. Clinical outcomes of and patient satisfaction with different incision methods for donor hepatectomy in living donor liver transplantation.

    PubMed

    Suh, Suk-Won; Lee, Kwang-Woong; Lee, Jeong-Moo; Choi, YoungRok; Yi, Nam-Joon; Suh, Kyung-Suk

    2015-01-01

    With the decrease in the average donor age and the increase in the proportion of female donors, both donor safety and cosmetic appearance are major concerns for some living donors in living donor liver transplantation (LDLT) because a large abdominal incision is needed that may influence the donor's quality of life. In all, 429 donors who underwent donor hepatectomy for LDLT from April 2010 to February 2013 were included in the study. Donors were divided into 3 groups based on the type of incision: conventional inverted L incision (n = 268; the C group), upper midline incision (n = 147; the M group), and transverse incision with laparoscopy (n = 14; the T group). Demographics, perioperative outcomes, postoperative complications for donors and recipients, and questionnaire-derived donor satisfaction with cosmetic appearance were compared. The mean age was lower (P < 0.001), the female ratio was higher (P < 0.001), and the body mass index (BMI) was lower (P = 0.017) in the M and T groups versus the C group. The operation time (P < 0.001) and the hospital stay duration (P = 0.010) were lowest in the M group. The postoperative complications did not differ by the type of incision and also did not show any significant effect in a multivariate analysis (P = 0.867). In the assessment of questionnaire-derived donor satisfaction matched by age (±5 years), sex, graft, height, weight, and BMI, a more satisfactory cosmetic result and more self-confidence were noted in the M and T groups versus the C group. In conclusion, the use of a minimal incision is technically feasible for some donor hepatectomy cases with a favorable safety profile. The patient satisfaction levels were greater with improved cosmetic outcomes in cases of minimal incision versus cases of conventional incision. PMID:25348280

  15. Liver transplantation from living donors with Gilbert's syndrome is a safe procedure for both donors and recipients.

    PubMed

    Tanoglu, Alpaslan; Artis, Tarik; Donmez, Ramazan; Kargi, Ahmet; Sit, Mustafa; Aslan, Serdar; Yazar, Serafettin; Beyazit, Yavuz; Polat, Kamil Yalcin

    2015-11-01

    Liver transplantation (LT) has become a favorable therapeutic option for patients with end-stage liver diseases. Gilbert's syndrome (GS) is a benign condition characterized by intermittent mild jaundice due to unconjugated hyperbilirubinemia. It is not obvious whether living-donor liver transplantation (LDLT) from a donor with GS could result in a normal outcome for both the recipient and the donor. We aimed to determine whether right lobe hepatectomy is a safe procedure for living donors with GS and LT recipients. Between September 2011 and March 2015, 305 LDLT procedures using right lobe grafts were performed at Atasehir Memorial Hospital, Istanbul, Turkey. Nineteen of 305 LT candidates who had been diagnosed with GS were included in the current study. After a 12-h overnight fast, total and indirect bilirubin levels of donors and recipients were measured. The median follow-up after transplant was 16 months (range 3-36 months). The median age of donors was 25 (range 20-55 yr). Four donors (21%) were female, and 15 donors (89%) were male. The median age of donors was 51 (range 23-68 yr). Eleven recipients (57%) were female, and 8 (43%) were male. The median preoperative total bilirubin level of donors was 1.69 mg/dL (range 1.26-2.43 mg/dL) (normal range <1.2 mg/dL). The median total bilirubin level of donors on postoperative day 7 was 1.04 mg/dL (range 0.71-3.23 mg/dL). As our study has included a large number of donors with GS, it produced reliable evidence that right lobe hepatectomy is a safe procedure for living donors with GS and LT recipients. PMID:26271485

  16. A brown dwarf mass donor in an accreting binary.

    PubMed

    Littlefair, S P; Dhillon, V S; Marsh, T R; Gänsicke, Boris T; Southworth, John; Watson, C A

    2006-12-01

    A long-standing and unverified prediction of binary star evolution theory is the existence of a population of white dwarfs accreting from substellar donor stars. Such systems ought to be common, but the difficulty of finding them, combined with the challenge of detecting the donor against the light from accretion, means that no donor star to date has a measured mass below the hydrogen burning limit. We applied a technique that allowed us to reliably measure the mass of the unseen donor star in eclipsing systems. We were able to identify a brown dwarf donor star, with a mass of 0.052 +/- 0.002 solar mass. The relatively high mass of the donor star for its orbital period suggests that current evolutionary models may underestimate the radii of brown dwarfs. PMID:17158322

  17. Nature of Oxygen Donor in Czochralski-Grown Silicon

    NASA Astrophysics Data System (ADS)

    Fukuoka, Noboru; Yoneta, Minoru; Miyamura, Reiko; Saito, Haruo

    1987-02-01

    Changes in the substitutional carbon and interstitial oxygen concentrations due to the formation of oxygen donors were studied on carbon-rich Czochralski-grown silicon (7--9× 1017 carbon atoms/cm3). The result suggests that the new donor formation is controlled not by the substitutional carbon concentration directly, but by a density of some unknown embryo. A donor formation was observed in a 450°C annealing which was preceded by a 650°C annealing without new donor formation. This donor does not exhibit a 0.767 eV line in a measurement of the photoluminescence spectrum. However, it exhibits an infrared absorption band which is characteristic to the thermal donor.

  18. Detection of La Crosse arbovirus antigen in mosquito pools: application of chromogenic and fluorogenic enzyme immunoassay systems.

    PubMed Central

    Hildreth, S W; Beaty, B J; Meegan, J M; Frazier, C L; Shope, R E

    1982-01-01

    An enzyme immunoassay producing either a chromogenic or fluorogenic end product was developed and evaluated for detecting La Crosse viral antigen within mosquito pools. The enzyme immunoassay was found to be sensitive, detecting one infected mosquito within a pool of 100 mosquitoes, and specific, distinguishing between closely related California group viruses. Assays were completed within 5 h after the addition of test samples. La Crosse viral antigen could be readily detected in mosquito pools after seven freeze-thaw cycles. PMID:7047555

  19. A highly efficient colorimetric immunoassay using a nanocomposite entrapping magnetic and platinum nanoparticles in ordered mesoporous carbon.

    PubMed

    Kim, Moon Il; Ye, Youngjin; Woo, Min-Ah; Lee, Jinwoo; Park, Hyun Gyu

    2014-01-01

    Nanocomposite to achieve ultrafast immunoassay: a new synergistically integrated nanocomposite consisting of magnetic and platinum nanoparticles, simultaneously entrapped in mesoporous carbon, is developed as a promising enzyme mimetic candidate to achieve ultrafast colorimetric immunoassays. Using new assay system, clinically important target molecules, such as human epidermal growth factor receptor 2 (HER2) and diarrhea-causing rotavirus, can be detected in only 3 min at room temperature with high specificity and sensitivity. PMID:23832855

  20. HCV Genotypes, Characterization of Mutations Conferring Drug Resistance to Protease Inhibitors, and Risk Factors among Blood Donors in São Paulo, Brazil

    PubMed Central

    Nishiya, Anna S.; de Almeida-Neto, Cesar; Ferreira, Suzete C.; Alencar, Cecília S.; Di-Lorenzo-Oliveira, Claudia; Levi, José E.; Salles, Nanci A.; Mendrone, Alfredo; Sabino, Ester C.

    2014-01-01

    Background Hepatitis C virus (HCV) infection is a global health problem estimated to affect almost 200 million people worldwide. The aim of this study is to analyze the subtypes and existence of variants resistant to protease inhibitors and their association with potential HCV risk factors among blood donors in Brazil. Methods Repeat anti-HCV reactive blood donors are systematically asked to return for retest, notification, and counseling in which they are interviewed for risk factors for transfusion-transmitted diseases. We analyzed 202 donors who returned for counseling from 2007 to 2010 and presented enzyme immunoassay- and immunoblot-reactive results. The HCV genotypes and resistance mutation analyses were determined by the direct sequencing of the NS5b and NS3 regions, respectively. The HCV viral load was determined using an in-house real-time PCR assay targeting the 5′-NCR. Results HCV subtypes 1b, 1a, and 3a were found in 45.5%, 32.0%, and 18.0% of the donors, respectively. The mean viral load of genotype 1 was significantly higher than that of the genotype 3 isolates. Subtype 1a was more frequent among young donors and 3a was more frequent among older donors. Protease inhibitor-resistant variants were detected in 12.8% of the sequenced samples belonging to genotype 1, and a higher frequency was observed among subtype 1a (20%) in comparison to 1b (8%). There was no difference in the prevalence of HCV risk factors among the genotypes or drug-resistant variants. Conclusions We found a predominance of subtype 1b, with an increase in the frequency of subtype 1a, in young subjects. Mutations conferring resistance to NS3 inhibitors were frequent in treatment-naïve blood donors, particularly those infected with subtype 1a. These variants were detected in the major viral population of HCV quasispecies, have replicative capacities comparable to nonresistant strains, and could be important for predicting the response to antiviral triple therapy. PMID:24466079