scholarly journals Validation of a Dissociation Enhanced Lanthanide Fluorescence Immunoassay for the Screening of 17 -Estradiol in Bovine Serum According to European Union Decision 2002/657/EC

2007 ◽  
Vol 90 (5) ◽  
pp. 1427-1431 ◽  
Author(s):  
Daniela Scalas ◽  
Stefania Squadrone ◽  
Marilena Gili ◽  
Daniela Marchis ◽  
Marino Prearo ◽  
...  
Keyword(s):  
European Union ◽  
Bovine Serum ◽  
False Negative ◽  
Screening Tests ◽  
Rapid Screening ◽  
Fluorescence Immunoassay ◽  
Serum Samples ◽  
Related Substances ◽  
The Matrix ◽  
Negative Effect

Abstract A validation study was carried out in order to evaluate the performances of a dissociation enhanced lanthanide fluorescence immunoassay (DELFIA) for rapid screening of 17 -Estradiol in bovine serum. This validation was performed according to European Union (EU) Decision 2002/657/EC, which establishes criteria and procedures for determination of detection capability (CC), selectivity/specificity, and applicability/ruggedness/stability for qualitative screening tests. To determine these performance characteristics, 20 blank serum samples of cattle were collected and spiked with 17 -Estradiol at 40 pg/mL, corresponding to the maximum residue limit permitted by Italian legislation. According to the EU Decision CC criterion, spiked samples must have <5 probability to be classified as a false negative. 17 -Estradiol was detected in each spiked sample, and the CC results were <40 pg/mL. There was also no observed interference effect due to chemically related substances or from the matrix. Moreover, slight variations of some critical factors in the DELFIA procedure, deliberately introduced for ruggedness evaluation, did not result in any negative effect on the 17 -Estradiol detection. The proposed method is suitable for qualitative screening analysis of 17 -Estradiol according to EU performance requirements.

scholarly journals False Positivity in a Cyto-ELISA for Anti-Endothelial Cell Antibodies Caused by Heterophile Antibodies to Bovine Serum Proteins

2000 ◽  
Vol 46 (2) ◽  
pp. 273-278 ◽  
Author(s):  
Ronan Revelen ◽  
Anne Bordron ◽  
Maryvonne Dueymes ◽  
Pierre Youinou ◽  
Josiane Arvieux
Keyword(s):  
Endothelial Cell ◽  
Bovine Serum ◽  
Serum Proteins ◽  
Solid Phase ◽  
Calf Serum ◽  
Blocking Agent ◽  
Screening Tests ◽  
Tween 20 ◽  
Serum Samples ◽  
Antibody Absorption

Abstract Background: ELISAs with fixed endothelial cells or cell lines are widely used screening tests for anti-endothelial cell antibodies (AECAs), but spurious increases occur. We examined interferences by heteroantibodies and means to eliminate them. Methods: AECAs were measured by ELISA on fixed layers of the human endothelial cell line, EA.hy 926, in a panel of 60 patient serum samples diluted in bovine serum albumin. Heteroantibodies against fetal calf serum (FCS) proteins were demonstrated and characterized in an ELISA—the interference assay—that used FCS-coated plates and Tween 20-containing buffer as blocking agent and sample diluent, as well as by immunoblotting. Results: In 12 of 60 patient serum samples, spurious increases of AECA titers were produced by endogenous antibodies reacting with FCS proteins from culture medium that were coated onto the solid-phase at the time of cell plating. This mechanism of interference was supported experimentally by exposing extracellular matrix, varying cell density, and incubating wells with FCS alone. The heterophile antibodies were mainly IgG and IgA, and in inhibition experiments, they recognized serum proteins from goat, sheep, and horse. Washing cells free of FCS before plating, or adding FCS (100 mL/L) to the patient sample diluent eliminated spurious signals from all 30 tested sera, but the latter method had practical advantages. Conclusions: Antibodies against animal serum proteins are a frequent cause of erroneous results in cyto-ELISAs. The interference can be eliminated by simple antibody absorption in FCS-containing dilution buffer.

Diagnostic screening of urban soil contaminants using diffuse reflectance spectroscopy

Soil Research ◽  
2009 ◽  
Vol 47 (4) ◽  
pp. 433 ◽  
Author(s):  
J. G. P. Bray ◽  
R. Viscarra Rossel ◽  
A. B. McBratney
Keyword(s):  
Heavy Metals ◽  
Prediction Accuracy ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
False Negative ◽  
Reflectance Spectroscopy ◽  
Screening Tests ◽  
Rapid Screening ◽  
Diagnostic Screening ◽  
Soil Contaminants

There is increasing demand for cheap and rapid screening tests for soil contaminants in environmental consultancies. Diffuse reflectance spectroscopy (DRS) in the visible-near infrared (vis-NIR) and mid infrared (MIR) has the potential to meet this demand. The aims of this paper were to develop diagnostic screening tests for heavy metals and polycyclic aromatic hydrocarbons (PAH) in soil using vis-NIR and MIR DRS. Cadmium, copper, lead, and zinc were analysed, as were total PAH and benzo[a]pyrene. An ordinal logistic regression technique was used for the screening and predictions of either contaminated or uncontaminated soil at different thresholds. We calculated the rates of false positive and false negative predictions and derived Receiver Operating Characteristic curves to explore how the choice of a threshold affects their proportion. Zinc and copper had the best prediction accuracies of the heavy metals, with 89% and 85%, respectively. Cadmium and lead had the lowest prediction accuracies, with 68% and 67%, respectively. PAH predictions averaged 78.9%. With an average prediction accuracy of 79.9%, MIR analysis was only slightly more accurate than vis-NIR analysis, which had an average prediction accuracy of 77.5%. However, vis-NIR may be used in situ, thereby reducing cost and time of analysis and providing diagnosis in ‘real-time’. DRS in the vis-NIR can substantially decrease both the time and cost associated with screening for soil contaminants.

scholarly journals OC 8435 MULTI-BIOMARKER TEST STRIP FOR POINT-OF-CARE SCREENING FOR ACTIVE TUBERCULOSIS: A FIVE-COUNTRY MULTI-CENTRE TEST EVALUATION

2019 ◽  
Vol 4 (Suppl 3) ◽  
pp. A6.2-A6
Author(s):  
Paul Corstjens ◽  
Anouk Van Hooij ◽  
Elisa Tjon Kon Fat ◽  
Shannon Herdigein ◽  
Anna Ritah Namuganga ◽  
...  
Keyword(s):  
Respiratory Diseases ◽  
Serum Proteins ◽  
Point Of Care ◽  
Low Cost ◽  
Test Strip ◽  
Screening Tests ◽  
Rapid Screening ◽  
Serum Samples ◽  
Multiple Test ◽  
Biomarker Selection

BackgroundInexpensive rapid screening tests that can be used at the point-of-care (POC) are vital to combat tuberculosis. Particularly, less invasive non-sputum-based biomarker tests for all TB forms can help controlling transmission. Availability of such tests would significantly accelerate and streamline diagnostic approaches, improve cost-efficiency and decrease unnecessary costly GeneXpert referrals.MethodsMulti-biomarker test (MBT) devices measuring levels of selections of up to six serum proteins simultaneously on a single lateral flow (LF) strip were produced. The strip contains individual capture lines for a biomarker selection allowing discrimination of TB-patients from other respiratory diseases (ORD). Only biomarkers successfully evaluated with singleplex strips (single biomarker tests) were applied to the MBT device. Quantitative signals are recorded with a low-cost handheld reader compatible with the applied luminescent up-converting particle (UCP) label. Biomarker selection and algorithms used to distinguish potential-TB and ORD are flexible.ResultsResults obtained with MBT strips containing multiple test lines correlate well with singleplex LF strips. Using LF tests for 5 selected biomarkers a sensitivity of 94% and specificity of 96% could be achieved with a confirmed South African selection of 20 TB and 31 non-TB samples. Patients were designated TB positive when scoring a value above the cut-off threshold for at least 3 out of 5 biomarkers. Serum samples of potential TB patients collected at five medical research institutes (Ethiopia, Namibia, South Africa, The Gambia, Uganda) were tested locally with MBT strips comprised of CRP, SAA, IP-10, Ferritin, ApoA-I and IL-6 and results analysed to obtain an overall pan-Africa applicable signature.ConclusionEvaluated POC applicable UCP-LF devices detecting serum biomarker signatures can help to distinguish active TB from other respiratory diseases and as such can prioritise highest-risk patients for further care. Ongoing prospective studies evaluate the MBT strip with fingerstick blood and do not require a laboratory or trained phlebotomist anymore.

Evaluation of an indirect fluorescence immunoassay for the detection of serum antibodies againstBabesia divergensin humans

Parasitology ◽  
2006 ◽  
Vol 134 (2) ◽  
pp. 179-185 ◽  
Author(s):  
D. DUH ◽  
M. JELOVšEK ◽  
T. AVšIČ-ŽUPANC
Keyword(s):  
False Negative ◽  
Cross Reactivity ◽  
Molecular Techniques ◽  
Fluorescence Immunoassay ◽  
Serum Samples ◽  
Babesia Divergens ◽  
Serological Studies ◽  
Human Sera ◽  
History Of ◽  
Positive Results

Since an indirect fluorescence immunoassay (IFA) for the detection of specific antibodies againstBabesia divergensin human sera is not commercially available, an in-house preparedB. divergensIFA for the examination of bovine sera was established for serological studies in humans. To determine whether the described IFA is appropriate for such studies, 2B. divergensantigens (of human or bovine origin) were tested using serum samples obtained from febrile human patients with a history of ‘tick bite’. Sera from other species of animals infected withB. divergens,BabesiaEU1,B. microtiorB. caniswere also included for comparative purposes. All serum samples were also tested using a commercially available IFA for the detection of antibodies againstB. microti, and the results compared with those obtained using blood smear and molecular techniques. This study showed that the evaluation and standardization of aB. divergensIFA for testing human sera is critical and that differentB. divergensantigens provide different end-point titres of antibodies, leading to false negative or positive results. Serological cross-reactivity betweenB. divergensandBabesiaEU1 needs to be taken into account when interpreting IFA results.

Rapid Screening Methods for Bleeding Disorders. A Three Year Survey

1964 ◽  
Vol 11 (02) ◽  
pp. 506-512 ◽  
Author(s):  
V. A Lovric ◽  
J Margolis
Keyword(s):  
Laboratory Tests ◽  
Capillary Blood ◽  
Screening Tests ◽  
Rapid Screening ◽  
Screening Methods ◽  
Bleeding Disorders ◽  
Routine Laboratory ◽  
Clotting Time ◽  
Kaolin Clotting Time ◽  
In Infants And Children

SummaryAn adaptation of “kaolin clotting time” and prothrombin time for use on haemolysed capillary blood provided simple and sensitive screening tests suitable for use in infants and children. A survey of three year’s experience shows that these are reliable routine laboratory tests for detection of latent coagulation disorders.

scholarly journals Systematic Review of Alexithymia in the Population of Hemodialysis Patients

2021 ◽  
Vol 10 (13) ◽  
pp. 2862
Author(s):  
Đorđe Pojatić ◽  
Ivana Tolj ◽  
Davorin Pezerović ◽  
Dunja Degmečić
Keyword(s):  
Mental Health ◽  
Literature Review ◽  
Web Of Science ◽  
Major Effect ◽  
Hemodialysis Patients ◽  
Bibliographic Databases ◽  
Inclusion Criteria ◽  
The Matrix ◽  
Negative Effect ◽  
Bodily Sensations

Alexithymia is a construct defined as the inability to differentiate between emotional experiences and bodily sensations. According to existing knowledge, alexithymia may have a major effect on the process of treatment and the outcome of the hemodialysis disease. The objective of this literature review was to determine the significance that alexithymia has for compliance and variables of clinical and mental health in the population of hemodialysis patients. For the above purpose, bibliographic databases “MEDLINE” and “Web of Science” were searched. The matrix method was used in analysis of articles. Searching both databases resulted in 248 articles. After applying exclusion and inclusion criteria, we included results of 13 articles in the literature review. The results of the search are findings regarding the prevalence and correlation of alexithymia with variables of clinical and mental health in hemodialysis patients. Alexithymia is significantly more common in the population of hemodialysis patients, and it has a negative effect on their mental and somatic health. Alexithymia levels in hemodialysis patients are more pronounced in cases where there is a greater number of comorbidities. Alexithymia is the predictor of high mortality rate in the population of hemodialysis patients, independent of other comorbidities.

scholarly journals Identification of TGF-β receptor-1 as a key regulator of carbon nanotube-induced fibrogenesis

2015 ◽  
Vol 309 (8) ◽  
pp. L821-L833 ◽  
Author(s):  
Anurag Mishra ◽  
Todd A. Stueckle ◽  
Robert R. Mercer ◽  
Raymond Derk ◽  
Yon Rojanasakul ◽  
...  
Keyword(s):  
Lung Fibrosis ◽  
Human Lung ◽  
Lung Fibroblasts ◽  
Screening Tests ◽  
Rapid Screening ◽  
Interstitial Tissue ◽  
Collagen Production ◽  
Human Lung Fibroblasts ◽  
Β Receptor ◽  
Tgf Β1

Carbon nanotubes (CNTs) induce rapid interstitial lung fibrosis, but the underlying mechanisms are unclear. Previous studies indicated that the ability of CNTs to penetrate lung epithelium, enter interstitial tissue, and stimulate fibroblasts to produce collagen matrix is important to lung fibrosis. In this study, we investigated the activation of transforming growth factor-β receptor-1 [TGF-β R1; i.e., activin receptor-like kinase 5 (ALK5) receptor] and TGF-β/Smad signaling pathway in CNT-induced collagen production in human lung fibroblasts. Human lung fibroblasts and epithelial cells were exposed to low, physiologically relevant concentrations (0.02–0.6 μg/cm2) of single-walled CNTs (SWCNT) and multiwalled CNTs (MWCNT) in culture and analyzed for collagen, TGF-β1, TGF-β R1, and SMAD proteins by Western blotting and immunofluorescence. Chemical inhibition of ALK5 and short-hairpin (sh) RNA targeting of TGF-β R1 and Smad2 were used to probe the fibrogenic mechanism of CNTs. Both SWCNT and MWCNT induced an overexpression of TGF-β1, TGF-β R1 and Smad2/3 proteins in lung fibroblasts compared with vehicle or ultrafine carbon black-exposed controls. SWCNT- and MWCNT-induced collagen production was blocked by ALK5 inhibitor or shRNA knockdown of TGF-β R1 and Smad2. Our results indicate the critical role of TGF-β R1/Smad2/3 signaling in CNT-induced fibrogenesis by upregulating collagen production in lung fibroblasts. This novel finding may aid in the design of mechanism-based risk assessment and development of rapid screening tests for nanomaterial fibrogenicity.

scholarly journals A Critical Review of Rapid Screening Tests for The Detection of Group B Streptococcus in Pregnancy 1212

1998 ◽  
Vol 43 ◽  
pp. 208-208
Author(s):  
Janet Bodley ◽  
Rose Kung ◽  
Arne Ohlsson ◽  
Gary Foster ◽  
Kofi Amankwah
Keyword(s):  
Critical Review ◽  
Group B Streptococcus ◽  
Screening Tests ◽  
Rapid Screening ◽  
Group B ◽  
In Pregnancy

Identification of Streptococcus pyogenes in a Pediatric Outpatient Department: A Practical System Designed for Rapid Results and Resident Teaching

PEDIATRICS ◽  
1974 ◽  
Vol 54 (6) ◽  
pp. 718-723
Author(s):  
Katherine Sprunt ◽  
Dorothea Vail ◽  
Russell S. Asnes
Keyword(s):  
False Positive ◽  
Fluorescent Antibody ◽  
False Negative ◽  
Screening Method ◽  
Rapid Screening ◽  
Resident Teaching ◽  
Antibody Uptake ◽  
Busy Clinic ◽  
Group A ◽  
Laboratory Tool

A rapid screening method for identification of clinic patients with pharyngitis who are carrying group A beta-hemolytic streptococci and for teaching residents the values and limitations of the culture-disk approach to identification has been reviewed as developed for a busy clinic and a busy hospital laboratory. Identification of positive cultures in less than 24 hours, using Taxos A disk and specific fluorescent antibody uptake, resulted in 12% apparent false-positive and 3.6% false-negative reports. However, when viewed in the light of the techniques used for verifying results, there were probably 3% false-positive and 3% false-negative reports. The screening method is considered acceptably reliable and practical as a laboratory tool and a resident teaching device.

scholarly journals Correlation between maternal serum biochemical markers with karyotyping for prenatal screening of foetal chromosomal abnormalities

2017 ◽  
Vol 6 (11) ◽  
pp. 4851
Author(s):  
Ketki S. Kulkarni ◽  
Payal Lakhani ◽  
Sujata A. Dalvi ◽  
Chandrashankar Gupta
Keyword(s):  
Prenatal Screening ◽  
Chromosomal Abnormalities ◽  
Tertiary Care ◽  
False Negative ◽  
Positive Likelihood Ratio ◽  
Screening Tests ◽  
Confirmatory Test ◽  
Singleton Pregnancy ◽  
True Negative ◽  
Marker Test

Background: Prenatal screening for chromosomal abnormalities can be done by biochemical screening tests like dual marker test (DMT), triple marker test (TMT) and quadruple marker test (QMT). It is important to identify ideal screening test among them which best correlates with result of karyotyping which is confirmatory test of foetal chromosomal abnormalities. This helps to decrease need for invasive prenatal tests for foetal karyotyping. This study aims to evaluate sensitivity, specificity, diagnostic accuracy and correlation of DMT, TMT, and QMT with results of karyotyping.Methods: Retrospective observational study was conducted in tertiary care maternity hospital over one year- 1st January 2015 to 31st December 2015. Women with singleton pregnancy undergoing DMT, TMT or QMT were included.Results: Of the 529 women screened by biochemical marker tests, 462 (87.33%) were screen negative and 67 (12.66%) women were screen positive. In 56 women, it was false positive (83.58%) and in 11 women true positive (16.41%). In 461 women the test results were true negative (99.78%), but in one case, result was false negative (0.21%).  3/11 (27.27%)women with foetal chromosomal abnormalities were primigravidae. 4/11 (36.36%)women were below 35 years. DMT and QMT had higher sensitivity (both 100%) and specificity (90.00% and 93.18% respectively) than TMT (sensitivity 80% and specificity 82.61%). Positive likelihood ratio (LR+) was 1.00 in DMT. Diagnostic odds ratio was highest with DMT (DOR=115.11) and best correlated with karyotyping results (coefficient of correlation 0.4).Conclusions: Universal screening of antenatal women, irrespective of their age and parity is suggested. DMT has highest diagnostic value and best correlation with the results of karyotyping. Hence the dual marker test can be considered to be better test for screening for aneuploidy.

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