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1.
Asian Pac J Cancer Prev ; 23(2): 429-433, 2022 02 01.
Article in English | MEDLINE | ID: mdl-35225453

ABSTRACT

BACKGROUND AND OBJECTIVES: Human Epidermal Growth Factor Receptor 2 (HER2/neu) is one of the most extensively studied proto-oncogens in breast cancer patients.  Accurate and timely assessment of the HER2/neu over expression is pivotal for the identification of breast cancer patients that could benefit from HER2-targeted therapy.  The present study was undertaken to investigate the diagnostic utility of serum HER2/neu testing by chemiluminescent immunoassay (CLIA) in breast cancer patients and compare it with the immunohistochemistry (IHC) method of HER2/neu expression. METHODS: Serum sample and tissue/paraffin block was collected from 52 patients with breast cancer before start of any anticancer regimen or hormonal therapy.  The tissue specimens were processed in Histopathology lab. Sections were immunostained with anti -estrogen receptor (ER) , anti -progesteron receptor (PR) and anti HER2/neu receptor  mouse monoclonal antibodies.) Serum HER2/neu was estimated using the chemiluminiscent immunoassay using 15ng/ml as the cut off. RESULTS: Out of 52 patients with breast cancer, serum HER2/neu was found elevated in 25(48.1%) patients and remaining 27(51.9%) showed normal serum HER2/neu concentrations. On IHC HER2/neu score was 3+ in 9(17.3%), 2+ in 10(19.2%), 1+ in 1(1.9%); while 32(61.5%) showed no HER2/neu expression.  31(59.6%) patients were ER positive and 28(53.8%) were PR positive. There was a significant correlation (P<0.001) of serum HER2 concentration with tissue expression of HER2/neu and Histological tumor grade. Serum HER2/neu levels showed a negative correlation with ER status (P=0.047) but no correlation with PR status. CONCLUSION: The result showed that the elevated serum HER2/neu was correlated with the IHC expression of HER2/neu in tissue and the histological grade of the tumor.  Findings suggest that post initial tissue diagnosis (IHC HER2/neu), serum HER2 assay may supplement subsequent tissue tests to monitor disease status and response to therapy.


Subject(s)
Breast Neoplasms/metabolism , Immunohistochemistry/statistics & numerical data , Luminescent Measurements/statistics & numerical data , Receptor, ErbB-2/analysis , Adult , Breast/metabolism , Breast Neoplasms/blood , Breast Neoplasms/pathology , Female , Humans , Middle Aged , Neoplasm Grading , Reproducibility of Results
2.
PLoS One ; 16(7): e0253807, 2021.
Article in English | MEDLINE | ID: mdl-34242264

ABSTRACT

Determining values of plasma renin activity (PRA) or plasma active renin concentration (ARC), plasma aldosterone concentration (PAC), and aldosterone-to-renin ratio (ARR) is essential to diagnose primary aldosteronism (PA), but it takes several days with conventional radioimmunoassays (RIAs). Chemiluminescent enzyme immunoassays for PAC and ARC using the Accuraseed® immunoanalyzer facilitated the determination, but relations between Accuraseed® immunoanalyzer-based and RIA-based values in samples of PA confirmatory tests and adrenal venous sampling remained to be elucidated. We addressed this issue in the present study. This is a prospective, cross-sectional study. ARC and PAC values were measured by the Accuraseed® immunoanalyzer in samples, in which PRA and PAC values had been measured by the PRA-FR® RIA and SPAC®-S Aldosterone kits, respectively. The relations between Accuraseed® immunoanalyzer-based and RIA-based values were investigated with regression analyses. The optimal cutoff of Accuraseed® immunoanalyzer-based ARR for PA screening was determined by the receiver operating characteristic analysis. After log-log transformations, linear relations with high coefficients of determination were observed between Accuraseed® immunoanalyzer-based and RIA-based data of renin and aldosterone. Following the PA guidelines of Japan Endocrine Society, Accuraseed® immunoanalyzer-based cutoffs were calculated from the regression equations: the basal PAC for PA screening >12 ng/dL, PAC for the saline infusion test >8.2 ng/dL, ARC for the furosemide-upright test <15 pg/mL, and ARR for the captopril challenge test >3.09 ng/dL per pg/mL. The optimal cutoff of Accuraseed® immunoanalyzer-based ARR for PA screening was >2.43 ng/dL over pg/mL not to overlook bilateral PA patients. The present study provided conversion formulas between Accuraseed® immunoanalyzer-based and RIA-based values of renin, aldosterone, and ARR, not only in basal samples but also in samples of PA confirmatory tests and adrenal venous sampling. Although validation studies are awaited, the present study will become priming water of harmonization of renin and aldosterone immunoassays.


Subject(s)
Aldosterone/blood , Hyperaldosteronism/diagnosis , Mass Screening/instrumentation , Renin/blood , Adult , Aged , Cross-Sectional Studies , Female , Humans , Hyperaldosteronism/blood , Japan , Luminescent Measurements/instrumentation , Luminescent Measurements/standards , Luminescent Measurements/statistics & numerical data , Male , Mass Screening/methods , Mass Screening/standards , Mass Screening/statistics & numerical data , Middle Aged , Prospective Studies , ROC Curve , Radioimmunoassay/instrumentation , Radioimmunoassay/standards , Radioimmunoassay/statistics & numerical data , Reference Values
3.
Sci Rep ; 11(1): 12498, 2021 06 14.
Article in English | MEDLINE | ID: mdl-34127729

ABSTRACT

Bioluminescence emissions from a few species of fireflies have been studied at different temperatures. Variations in the flash-duration have been observed and interesting conclusions drawn in those studies. Here we investigate steady-state and pulsed emissions from male specimens of the Indian species Sclerotia substriata at temperatures considerably higher and lower than the ones at which they normally flash. When the temperature is raised to 34 °C, the peak wavelength gets red-shifted and the emitted pulses become the narrowest which broaden considerably thereafter for small increases in temperature; this probably indicates denaturation of the enzyme luciferase catalyzing the light-producing reaction. When the temperature is decreased to the region of 10.5-9 °C, the peak gets blue-shifted and the flash-duration increased abnormally with large fluctuation; this possibly implies cold denaturation of the luciferase. We conclude that the first or hot effect is very likely to be the reason of the species being dark-active on hot days, and the second or cold one is the probable reason for its disappearance at the onset of the winter. Our study makes the inference that these two happenings determine the temperature-tolerance, which plays a major role in the selection of the habitat for the firefly.


Subject(s)
Cold Temperature/adverse effects , Fireflies/physiology , Luciferases, Firefly/metabolism , Luminescence , Thermotolerance/physiology , Animals , Hot Temperature/adverse effects , Hydrogen-Ion Concentration , Luminescent Measurements/statistics & numerical data , Male , Protein Denaturation , Seasons , Time Factors
4.
Ann Clin Biochem ; 58(5): 496-504, 2021 09.
Article in English | MEDLINE | ID: mdl-33845592

ABSTRACT

STUDY OBJECTIVE: SARS-CoV-2, which causes coronavirus disease (COVID-19), continues to cause significant morbidity and mortality. The diagnosis of acute infection relies on reverse transcription-polymerase chain reaction (RT-PCR)-based viral detection. The objective of this study was to evaluate the optimal serological testing strategy for anti-SARS-CoV-2 antibodies which provides an important indicator of prior infection and potential short-term immunity. METHODS: The sensitivity and specificity of four different ELISA assays (Euroimmun IgG, Euroimmun NCP-IgG, Fortress and DIAsource) and one CLIA assay (Roche ELECSYS) were evaluated in 423 samples; 137 patients with confirmed RT-PCR COVID-19 infection (true positives), and 100 pre-pandemic samples collected prior to October 2019 (true negatives). A further 186 samples were collected from health-care staff and analysed by all five assays. RESULTS: The Fortress ELISA assay demonstrated the highest sensitivity and specificity followed by the Roche ECLIA assay. The highest overall sensitivity came from the assays that measured total antibody (IgM-IgG combined) and the three assays that performed the best (Fortress, Roche, Euroimmun IgG) all have different antigens as their target proteins which suggests that antigen target does not affect assay performance. In mildly symptomatic participants with either a negative RT-PCR or no RT-PCR performed, 16.76% had detectable antibodies suggesting previous infection. CONCLUSIONS: We recommend a combined testing strategy utilizing assays with different antigenic targets using the fully automated Roche ECLIA assay and confirming discordant samples with the Fortress Total Antibody ELISA assay. This study provides an important indicator of prior infection in symptomatic and asymptomatic individuals.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/diagnosis , COVID-19/immunology , Pandemics , SARS-CoV-2 , Antibodies, Viral/blood , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing/statistics & numerical data , Electrochemical Techniques/methods , Electrochemical Techniques/statistics & numerical data , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/statistics & numerical data , Female , Health Personnel , Humans , Immunoglobulin G/blood , Ireland/epidemiology , Luminescent Measurements/methods , Luminescent Measurements/statistics & numerical data , Male , Pregnancy , Sensitivity and Specificity
5.
Biosens Bioelectron ; 176: 112942, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33401144

ABSTRACT

2019 novel coronavirus (2019-nCoV) with strong contagion in the crowd, has ravaged worldwide and severely impacts the human health and epidemic prevention system, by producing a series of significant stress reactions in the body to induce further cytokine storm. Transcription factors (TFs) served as essential DNA binding proteins play an integral role in regulating cytokine storm, and the detection of it in the human coronavirus environment provides especially valuable approaches to diagnosis and treatment of 2019-nCoV and development of antiviral drugs. In this work, an entropy-driven electrochemiluminescence (ECL) biosensor was constructed for ultra-sensitive bioassay of NF-κB p50. The strategy primarily capitalizing the splendid double-stranded DNA (dsDNA) binding properties of transcription factors, employing GOAu-Ru composite material as ECL emitter, utilizing entropy-driven reactions for signal amplification method, offered a repeatable proposal for TFs detection. In the absence of TFs, the released DNA1 further went in the entropy-driven reaction, contributing to an "ECL off" state. However, in the presence of TFs, the dsDNA avoided being digested, which blocked DNA1 for participating in the entropy-driven reaction, and the system exhibited an "ECL on" state. Most importantly, the ECL bioanalytical method denoted broad application prospects for NF-κB p50 detection with a lower detection limit (9.1 pM).


Subject(s)
Biosensing Techniques/methods , COVID-19/immunology , Cytokine Release Syndrome/immunology , NF-kappa B p50 Subunit/analysis , Biosensing Techniques/statistics & numerical data , COVID-19/complications , Cytokine Release Syndrome/etiology , Electrochemical Techniques/methods , Electrochemical Techniques/statistics & numerical data , Entropy , Humans , Limit of Detection , Luminescent Measurements/methods , Luminescent Measurements/statistics & numerical data , Pandemics , SARS-CoV-2 , Sensitivity and Specificity
6.
J Appl Lab Med ; 6(2): 491-495, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33098417

ABSTRACT

INTRODUCTION: Neutralizing antibodies (NAbs) are capable of binding to a virus to render it incapable of infection. The ability of commercially available SARS-CoV-2 serological tests to detect NAbs has not been widely reported. We sought to correlate the antibodies detected by an automated chemiluminescent immunoassay with NAbs. METHODS: Residual serum samples from 35 patients that had a positive antibody test using the LIAISON® SARS-CoV-2 S1/S2 IgG chemiluminescent immunoassay and 2 antibody-negative control sera were tested for NAbs using a plaque reduction neutralization test (PRNT). RESULTS: NAbs were detected in 66% (23/35) of the antibody-positive samples. The immunoassay signal value ranged from 21.7 to 131.3 AU/mL (median, 90.5) with significant correlation between it and the PRNT (r = 0.61, P = 0.002). In the samples without NAbs, the immunoassay signal ranged from 16.3 to 66.2 AU/mL (median, 27.2). An immunoassay signal cutoff of >41 AU/mL was 91% sensitive and 92% specific for the detection of NAbs. DISCUSSION: It is important that correlates of immunity to SARS-CoV-2 be identified and NAbs are considered to be central indicators of such. PRNT is the gold-standard test for identifying NAbs but it cannot be used for large-scale testing of populations. It is necessary to establish relationships between it and widely used commercial serological assays for SARS-CoV-2.


Subject(s)
Antibodies, Neutralizing/isolation & purification , Antibodies, Viral/isolation & purification , COVID-19 Serological Testing/standards , COVID-19/diagnosis , SARS-CoV-2/isolation & purification , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , COVID-19/virology , COVID-19 Serological Testing/instrumentation , COVID-19 Serological Testing/methods , COVID-19 Serological Testing/statistics & numerical data , Humans , Immunoglobulin G/immunology , Immunoglobulin G/isolation & purification , Luminescent Measurements/instrumentation , Luminescent Measurements/standards , Luminescent Measurements/statistics & numerical data , Neutralization Tests/standards , Neutralization Tests/statistics & numerical data , Reagent Kits, Diagnostic/standards , SARS-CoV-2/immunology , Sensitivity and Specificity
8.
J Appl Lab Med ; 5(6): 1313-1323, 2020 11 01.
Article in English | MEDLINE | ID: mdl-32717060

ABSTRACT

BACKGROUND: Little is known about the performance of the Roche novel severe acute respiratory syndrome coronavirus 2 antibody (anti-SARS-CoV-2) assay. We provide an extensive evaluation of this fully automated assay on Cobas e801/e602 immunoassay analyzers. METHODS: We assessed the linearity, precision, and throughput of the Roche anti-SARS-CoV-2 assay. Sensitivity was calculated from 349 SARS-CoV-2 polymerase chain reaction (PCR) positive samples; specificity was determined from 715 coronavirus disease 2019 (COVID-19)-naive samples. We examined cross-reactivity against other antibody positive samples [syphilis, rheumatoid factor (RF), antinuclear antibody (ANA), double-stranded DNA (ds-DNA), influenza, dengue, hepatitis B (HBV), hepatitis C (HCV)] and the anti-SARS-CoV-2 kinetics. RESULTS: The assay cut-off index (COI) was linear up to 90.8. The interassay precision was 2.9% for a negative control (COI = 0.1) and 5.1% for a positive control (COI = 3.0). Assay time is 18 min and results are available 1 min later; throughput for 300 samples was 76 min. Only 1 case positive for HBsAg tested falsely positive; specificity was 99.9%. The assay has a sensitivity of 97.1% 14 days after PCR positivity (POS) and 100% at ≥21 days POS; 48.2% of cases had anti-SARS-CoV-2 within 6 days POS. In 11 patients in whom serum was available prior to a positive antibody signal (COI ≥1.0) the interval between the last negative and first positive COI (time to "seroconversion") on average is 3 days (range 1-6 days) and 4 more days (range 1-7) for the anti-SARS-CoV-2 to plateau. CONCLUSION: The Roche anti-SARS-CoV-2 assay shows excellent performance with minimal cross-reactivity from other viral and confounding antibodies. Antibody development and seroconversion appears quite early.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/isolation & purification , Clinical Laboratory Techniques/instrumentation , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , Serologic Tests/instrumentation , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , Betacoronavirus/genetics , Betacoronavirus/immunology , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques/statistics & numerical data , Coronavirus Infections/blood , Coronavirus Infections/immunology , Coronavirus Infections/virology , Cross Reactions/immunology , Female , Fluoroimmunoassay/instrumentation , Fluoroimmunoassay/statistics & numerical data , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Luminescent Measurements/instrumentation , Luminescent Measurements/statistics & numerical data , Male , Middle Aged , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Polymerase Chain Reaction/statistics & numerical data , Predictive Value of Tests , RNA, Viral/isolation & purification , Reagent Kits, Diagnostic , SARS-CoV-2 , Seroconversion , Serologic Tests/statistics & numerical data , Time Factors , Young Adult
9.
PLoS One ; 15(3): e0229672, 2020.
Article in English | MEDLINE | ID: mdl-32214362

ABSTRACT

More than 170 types of human papilloma viruses (HPV) exist with many causing proliferative diseases linked to malignancy in indications such as cervical cancer and head and neck squamous cell carcinoma. Characterization of antibody levels toward HPV serology is challenging due to complex biology of oncoproteins, pre-existing titers to multiple HPV types, cross-reactivity, and low affinity, polyclonal responses. Using multiplex technology from MSD, we have developed an assay that simultaneously characterizes antibodies against E6 and E7 oncoproteins of HPV16 and 18, the primary drivers of HPV-associated oncogenesis. We fusion tagged our E6 and E7 proteins with MBP via two-step purification, spot-printed an optimized concentration of protein into wells of MSD 96-well plates, and assayed various cynomolgus monkey, human and HPV+ cervical cancer patient serum to validate the assay. The dynamic range of the assay covered 4-orders of magnitude and antibodies were detected in serum at a dilution up to 100,000-fold. The assay was very precise (n = 5 assay runs) with median CV of human serum samples ~ 5.3% and inter-run variability of 11.4%. The multiplex serology method has strong cross-reactivity between E6 oncoproteins from human serum samples as HPV18 E6 antigens neutralized 5 of 6 serum samples as strongly as HPV16 E6. Moderate concordance (Spearman's Rank = 0.775) was found between antibody responses against HPV16 E7 in the multiplex assay compared to standard ELISA serology methods. These results demonstrate the development of a high-throughput, multi-plex assay that requires lower sample quantity input with greater dynamic range to detect type-specific anti-HPV concentrations to E6 and E7 oncoproteins of HPV16 and 18.


Subject(s)
Antibodies, Viral/blood , Human papillomavirus 16/immunology , Human papillomavirus 18/immunology , Immunoassay/methods , Immunoglobulin G/blood , Animals , Antibody Specificity , Cross Reactions , DNA-Binding Proteins/immunology , Electrochemical Techniques , Enzyme-Linked Immunosorbent Assay , Female , High-Throughput Screening Assays/methods , High-Throughput Screening Assays/statistics & numerical data , Humans , Immunoassay/statistics & numerical data , Limit of Detection , Luminescent Measurements/methods , Luminescent Measurements/statistics & numerical data , Macaca fascicularis , Oncogene Proteins, Viral/immunology , Papillomavirus E7 Proteins/immunology , Repressor Proteins/immunology , Uterine Cervical Neoplasms/immunology , Uterine Cervical Neoplasms/virology
10.
Anal Biochem ; 554: 28-33, 2018 08 01.
Article in English | MEDLINE | ID: mdl-29860095

ABSTRACT

We designed a competitive aptamer chemiluminescence assay for ochratoxin A (OTA) on the surface of a single silica photonic crystal microsphere (SPCM) in cereal samples. The structural color of SPCMs is used to recognize and trace the microspheres during process of detection. Anti-aptamer was immobilized on the surface of SPCM. OTA and anti-aptamer competed to bind to aptamer when OTA and its aptamer (labeled by biotin at 5'end) were added in the system. The chemiluminescence signal was developed by the horseradish peroxidase (HRP), luminol and H2O2. The molecules on the single SPCM can produce enough chemiluminescence signal intensity for quantitative detection for OTA. The linear detection range for OTA was from 1 pg/mL to 1 ng/mL and recovery rates were 89%-95%, 81%-92% and 94%-105% in rice, wheat and corn, respectively. The results showed that the developed method for OTA using a single SPCM has a great application potential in cereal samples.


Subject(s)
Edible Grain/chemistry , Food Contamination/analysis , Luminescent Measurements/methods , Ochratoxins/analysis , Aptamers, Nucleotide , Calibration , Humans , Luminescent Measurements/statistics & numerical data , Microspheres , Optical Devices , Silicon Dioxide
11.
Anal Biochem ; 551: 1-3, 2018 06 15.
Article in English | MEDLINE | ID: mdl-29727603

ABSTRACT

This paper proposes a time-domain Gaussian-weighted noise reduction filter for bioluminescence measurement with low signal-to-noise ratio through photon counting. The filter was used for estimating the true fold-change signal from noisy gene expression data obtained through real-time dual-color luciferase assay. Furthermore, not only was the higher harmonics noise of the measurement system confirmed to reduce from the gene expression data but rapid and slow changes were also preserved in the estimated signal. In addition, the probability value of Pearson's chi-squared test was improved 257 times at most and 1.5 times on average without impairing the noise reduction ratio.


Subject(s)
Luminescent Measurements/methods , Chi-Square Distribution , Computer Systems , Gene Expression , Hep G2 Cells , Humans , Luciferases/genetics , Luciferases/metabolism , Luminescent Measurements/statistics & numerical data , Normal Distribution , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Signal-To-Noise Ratio
12.
Biomed Pharmacother ; 101: 74-86, 2018 May.
Article in English | MEDLINE | ID: mdl-29477474

ABSTRACT

Bioluminescence is the light produced by a living organism and is commonly emitted by sea life with Ca2+-regulated photoproteins being the most responsible for bioluminescence emission. Marine coelenterates provide important functions involved in essential purposes such as defense, feeding, and breeding. In this review, the main characteristics of marine photoproteins including aequorin, clytin, obelin, berovin, pholasin and symplectin from different marine organisms will be discussed. We will focused on the recent use of recombinant photoproteins in different biomedical research fields including the measurement of Ca2+ in different intracellular compartments of animal cells, as labels in the design and development of binding assays. This review will also outline how bioluminescent photoproteins have been used in a plethora of analytical methods including ultra-sensitive assays and in vivo imaging of cellular processes. Due to their unique properties including elective intracellular distribution, wide dynamic range, high signal-to-noise ratio and low Ca2+-buffering effect, recombinant photoproteins represent a promising future analytical tool in several in vitro and in vivo experiments.


Subject(s)
Biomedical Research/trends , Luminescent Measurements/statistics & numerical data , Luminescent Measurements/trends , Luminescent Proteins/chemistry , Luminescent Proteins/metabolism , Animals , Aquatic Organisms/chemistry , Aquatic Organisms/metabolism , Humans
13.
Eur J Clin Microbiol Infect Dis ; 37(4): 643-649, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29280085

ABSTRACT

The aim of this work was to ascertain the usefulness of a new commercially-available single-assay chemiluminescence test (CHT) for the diagnosis of human tularemia (Tularaemia VIRCLIA IgG + IgM monotest, Vircell, Santa Fe, Granada, Spain). A total of 773 sera from 773 patients including 364 initial sera from patients with diagnosed tularemia, patients with suspected tularemia not confirmed (100), healthy people (152), patients with serology positive to Brucella (97), patients diagnosed with other infectious diseases (30), and patients diagnosed with autoimmune diseases (30) were included. All sera were tested by CHT, "in-house" microagglutination test (MAT), immunochromatographic test (ICT) (Virapid Tularaemia, Vircell, Santa Fe Granada, Spain), and "in-house" ELISA IgG, and ELISA IgM. Of the total initial sera, 334 (sensitivity 91.8%) were positive in the CHT, 332 (sensitivity 91.2%) in the MAT, 330 (sensitivity 90.7%) in the ICT, and 328 (sensitivity 90.1%) in the ELISA IgG and ELISA IgM tests. The specificity of the CHT was 96.7%; of the MAT, 100%; of the ICT, 98.7%; and of the ELISA IgG and ELISA IgM, 97.4%. In the group of patients with serology positive to Brucella, at least 12.4% of sera were positive in tularemia tests (12.4% in ELISA IgM, 13.4% in MAT, 14.4% in ICT, and 15.5% in CHT and ELISA IgG). In conclusion, CHT presents a sensitivity and specificity in early diagnosis of human tularemia, similar to MAT, ICT, and ELISA IgG and ELISA IgM. Its single assay design allows lower costs, especially in areas of low endemicity or inter-epidemic periods.


Subject(s)
Antibodies, Bacterial/blood , Francisella tularensis/immunology , Immunoassay/methods , Luminescent Measurements/methods , Serologic Tests/methods , Tularemia/diagnosis , Adult , Aged , Case-Control Studies , Female , Humans , Immunoassay/economics , Immunoassay/statistics & numerical data , Immunoglobulin G/blood , Immunoglobulin M/blood , Luminescent Measurements/economics , Luminescent Measurements/statistics & numerical data , Male , Middle Aged , Predictive Value of Tests , Serologic Tests/economics , Serologic Tests/statistics & numerical data , Tularemia/microbiology
14.
AAPS J ; 19(1): 313-319, 2017 01.
Article in English | MEDLINE | ID: mdl-27873117

ABSTRACT

Biotherapeutics are known for their potential to induce drug specific immune responses, which are commonly evaluated by the detection of anti-drug antibodies (ADAs). For some biotherapeutics, pre-existing ADAs against drug have been observed in drug-naïve matrix. The presence of pre-existing drug specific antibodies may significantly complicate assessment of the screening ADA assay cutpoint value, which is usually established based on the statistical analysis of signal distribution from the drug-naïve individuals. A Gaussian mixture model-based approach is presented herein to address high prevalence of pre-existing ADAs to a modified monoclonal antibody-based biotherapeutic (m-mAb). A high prevalence of pre-existing anti-m-mAb antibodies was observed in drug-naïve individual cynomolgus monkey serum samples with signal ranging from 100 to 7000 relative light units (RLU, as determined in an electrochemiluminescence readout-based assay). Application of the industry standard statistical algorithm resulted in a relatively high floating screening assay cutpoint factor (CPF) of 9.80, which potentially would have reported a high percent of false negative samples. An alternative, Gaussian mixture model-based approach was applied to identify the least reactive individual samples in the tested population, which resulted in a floating screening assay CPF of 2.35. The low CPF value significantly reduced the risk of reporting false negative results. The proposed Gaussian mixture model-based approach described herein provides an alternate method for the calculation of biologically relevant screening assay CPF when high prevalence of pre-existing drug specific antibodies is observed.


Subject(s)
Antibodies, Monoclonal/blood , Biological Products/blood , Luminescent Measurements/methods , Models, Biological , Models, Statistical , Animals , Antibodies, Monoclonal/immunology , Antibodies, Monoclonal/therapeutic use , Biological Products/immunology , Biological Therapy/methods , False Positive Reactions , In Vitro Techniques , Luminescent Measurements/statistics & numerical data , Macaca fascicularis , Rats, Inbred Strains
15.
Anal Bioanal Chem ; 408(30): 8761-8770, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27040532

ABSTRACT

Water quality and water management are worldwide issues. The analysis of pollutants and in particular, heavy metals, is generally conducted by sensitive but expensive physicochemical methods. Other alternative methods of analysis, such as microbial biosensors, have been developed for their potential simplicity and expected moderate cost. Using a biosensor for a long time generates many changes in the growth of the immobilized bacteria and consequently alters the robustness of the detection. This work simulated the operation of a biosensor for the long-term detection of cadmium and improved our understanding of the bioluminescence reaction dynamics of bioreporter bacteria inside an agarose matrix. The choice of the numerical tools is justified by the difficulty to measure experimentally in every condition the biosensor functioning during a long time (several days). The numerical simulation of a biomass profile is made by coupling the diffusion equation and the consumption/reaction of the nutrients by the bacteria. The numerical results show very good agreement with the experimental profiles. The growth model verified that the bacterial growth is conditioned by both the diffusion and the consumption of the nutrients. Thus, there is a high bacterial density in the first millimeter of the immobilization matrix. The growth model has been very useful for the development of the bioluminescence model inside the gel and shows that a concentration of oxygen greater than or equal to 22 % of saturation is required to maintain a significant level of bioluminescence. A continuous feeding of nutrients during the process of detection of cadmium leads to a biofilm which reduces the diffusion of nutrients and restricts the presence of oxygen from the first layer of the agarose (1 mm) and affects the intensity of the bioluminescent reaction. The main advantage of this work is to link experimental works with numerical models of growth and bioluminescence in order to provide a general purpose model to understand, anticipate, or predict the dysfunction of a biosensor using immobilized bioluminescent bioreporter in a matrix.


Subject(s)
Biosensing Techniques/instrumentation , Cadmium/analysis , Luminescent Measurements/statistics & numerical data , Models, Biological , Water Pollutants, Chemical/analysis , Aliivibrio fischeri/chemistry , Aliivibrio fischeri/enzymology , Biofilms/drug effects , Biofilms/growth & development , Biosensing Techniques/methods , Cells, Immobilized , Computer Simulation , Environmental Monitoring/instrumentation , Escherichia coli/drug effects , Escherichia coli/enzymology , Escherichia coli/growth & development , Gene Expression , Genes, Reporter , Luciferases/genetics , Luciferases/metabolism , Oxygen/chemistry , Sepharose , Transgenes
16.
BMC Res Notes ; 8: 807, 2015 Dec 21.
Article in English | MEDLINE | ID: mdl-26689425

ABSTRACT

BACKGROUND: Our previous study into assessing hospital cleanliness in Japan by two common methods, ATP bioluminescence and the stamp agar method, revealed considerable variability in the data of both methods (BMC Research Notes, 7: 121, 2014). To investigate the reason(s) for the variability, we reanalyzed the data (n = 752) from the point of view of the material surface properties of sampling sites. METHODS: Data obtained from surfaces with unknown properties and different purposes such as floor were omitted, and the remaining data (n = 488) were used for this study. The material surface properties on sampling sites were divided into six categories: melamine coated (n = 216), vinyl chloride (n = 16), stainless steel (n = 144), wood (n = 63), and acrylonitrile-butadiene styrene resin coated (n = 48). The data between individual material properties were compared. RESULTS: The ATP values of high-touch places were significantly different depending on the type of surface, but no significant difference in stamp values between material properties was seen, indicating that in contrast to stamp values, ATP-accumulation more depends on the physical properties of the material surface such as electronic charges or roughness. To confirm this, we assessed a degree of roughness on vinyl chloride material surface (disutilized floor samples actually used for each of the hospitals) by observation with scanning electron microscope (SEM). As a result, SEM observation similarly revealed considerable roughness on the materials, which may allow microbes to contaminate the materials without noticing it. CONCLUSION: Material properties must be considered when evaluating hospital cleanliness with ATP values, and provide a strong warning into evaluating hospital cleanliness.


Subject(s)
Adenosine Triphosphate , Hospitals/standards , Luminescent Measurements/standards , Microscopy, Electron, Scanning/standards , Equipment Contamination/statistics & numerical data , Hospitals/statistics & numerical data , Humans , Japan , Luminescent Measurements/statistics & numerical data , Microscopy, Electron, Scanning/statistics & numerical data , Surface Properties
17.
J Immunol Methods ; 395(1-2): 29-36, 2013 Sep 30.
Article in English | MEDLINE | ID: mdl-23810835

ABSTRACT

In this study, an indirect competitive enzyme-linked immunosorbent assay with chemiluminescent (CLELISA) detection for 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ) was developed. A monoclonal antibody (MAb) against AMOZ was prepared through immunizing BALB/c mice with 4-carboxybenzaldehyle derivatized AMOZ (CPAMOZ), conjugated with bovine serum albumin (BSA) as antigen. The effects of the substrates luminol, p-iodophenol and urea peroxide on the performance of the assay were studied and optimized. In addition, the specificity of the MAb, estimated as the cross-reactivity values with 4-nitrobenzaldehyde derivatized AMOZ (NPAMOZ), CPAMOZ and AMOZ, was 100%, 27.45% and 0.18%, respectively. The sensitivity of the developed CLELISA was estimated as 50% inhibitory concentration (IC50) value (0.14µg/l) with a linear working range between 0.03 and 64µg/l, and a limit of detection of 0.01µg/l. The CLELISA described in this study was 5-fold more sensitive than the indirect competitive ELISA previously developed in our laboratory. Finally, this new CLELISA was compared with a commercial kit to detect NPAMOZ in spiked fish, shrimp, honey and egg samples. The recovery values from four spiked fish, shrimp, honey and egg samples with different concentrations of NPAMOZ in CLELISA were 92.1-107.7%. Thus, the immunoassay method described here has a broad detection range and high sensitivity and is a valid and cost-effective means for high throughput monitoring of residual AMOZ levels in fish, shrimps, honey and eggs with potential applications in other animal tissues.


Subject(s)
Drug Residues/analysis , Enzyme-Linked Immunosorbent Assay/methods , Food Contamination/analysis , Luminescent Measurements/methods , Morpholines/analysis , Nitrofurans/metabolism , Oxazolidinones/analysis , Oxazolidinones/metabolism , Animals , Antibodies, Monoclonal , Antibody Specificity , Cattle , Cross Reactions , Eggs/analysis , Enzyme-Linked Immunosorbent Assay/statistics & numerical data , Female , Fishes/metabolism , Honey/analysis , Luminescent Measurements/statistics & numerical data , Mice , Mice, Inbred BALB C , Morpholines/immunology , Oxazolidinones/immunology , Penaeidae/chemistry
18.
Comput Math Methods Med ; 2013: 619658, 2013.
Article in English | MEDLINE | ID: mdl-23840280

ABSTRACT

Differentiating lymphomas and glioblastomas is important for proper treatment planning. A number of works have been proposed but there are still some problems. For example, many works depend on thresholding a single feature value, which is susceptible to noise. In other cases, experienced observers are required to extract the feature values or to provide some interactions with the system. Even if experts are involved, interobserver variance becomes another problem. In addition, most of the works use only one or a few slice(s) because 3D tumor segmentation is time consuming. In this paper, we propose a tumor classification system that analyzes the luminance distribution of the whole tumor region. Typical cases are classified by the luminance range thresholding and the apparent diffusion coefficients (ADC) thresholding. Nontypical cases are classified by a support vector machine (SVM). Most of the processing elements are semiautomatic. Therefore, even novice users can use the system easily and get the same results as experts. The experiments were conducted using 40 MRI datasets. The classification accuracy of the proposed method was 91.1% without the ADC thresholding and 95.4% with the ADC thresholding. On the other hand, the baseline method, the conventional ADC thresholding, yielded only 67.5% accuracy.


Subject(s)
Brain Neoplasms/classification , Brain Neoplasms/diagnosis , Diffusion Magnetic Resonance Imaging/methods , Glioblastoma/classification , Glioblastoma/diagnosis , Lymphoma/classification , Lymphoma/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Algorithms , Child , Computational Biology , Databases, Factual/statistics & numerical data , Diagnosis, Differential , Diffusion Magnetic Resonance Imaging/statistics & numerical data , Female , Humans , Imaging, Three-Dimensional/statistics & numerical data , Luminescent Measurements/methods , Luminescent Measurements/statistics & numerical data , Male , Middle Aged , Retrospective Studies , Support Vector Machine , Young Adult
19.
Clin Dev Immunol ; 2013: 703759, 2013.
Article in English | MEDLINE | ID: mdl-23476678

ABSTRACT

OBJECTIVE: To analyze the clinical value of anti-DFS70 antibodies in a cohort of patients undergoing routine antinuclear antibodies (ANAs) testing. METHODS: Sera with a dense fine speckled (DFS) indirect immunofluorescence (IIF) pattern from 100 consecutive patients and 100 patients with other IIF patterns were tested for anti-DFS70 antibodies by a novel chemiluminescence immunoassay (CIA) and for ANA by ANA Screen ELISA (both INOVA). RESULTS: Among the 100 patients with a DFS IIF pattern, 91% were anti-DFS70 positive by CIA compared to 3% in the comparator group (P < 0.0001). The CIA and IIF titers of anti-DFS antibodies were highly correlated (rho = 0.89). ANA by ELISA was positive in 35% of patients with the DFS IIF pattern as compared to 67% of patients with other patterns (P < 0.0001). Only 12.0% of patients with DFS pattern and 13.4% with DFS pattern and anti-DFS70 antibodies detected by CIA had systemic autoimmune rheumatic disease (SARD). Only 5/91 (5.5%) patients with anti-DFS70 antibodies had SARD and their sera were negative on the ANA Screen ELISA. CONCLUSION: Although anti-DFS70 antibodies cannot exclude the presence of SARD, the likelihood is significantly lower than in patients with other IIF patterns and should be included in test algorithms for ANA testing.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , Autoimmune Diseases/diagnosis , Rheumatic Diseases/diagnosis , Serologic Tests/methods , Transcription Factors/immunology , Algorithms , Antibodies/blood , Antibodies, Antinuclear/blood , Autoimmune Diseases/immunology , Cohort Studies , Diagnostic Tests, Routine , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/statistics & numerical data , Fluorescent Antibody Technique, Indirect/methods , Fluorescent Antibody Technique, Indirect/statistics & numerical data , Humans , Luminescent Measurements/methods , Luminescent Measurements/statistics & numerical data , Predictive Value of Tests , Rheumatic Diseases/immunology , Serologic Tests/statistics & numerical data , Tertiary Care Centers
20.
J Biomed Opt ; 18(2): 26013, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23389682

ABSTRACT

As a high-sensitivity imaging modality, bioluminescence tomography can reconstruct the three-dimensional (3-D) location of an internal luminescent source based on the 3-D surface light distribution. However, we can only get the multi-orientation two-dimensional (2-D) bioluminescence distribution in the experiments. Therefore, developing an accurate universal registration method is essential for following bioluminescent source reconstruction. We can then map the multi-orientation 2-D bioluminescence distribution to the 3-D surface derived from anatomical information with it. We propose a 2-D -to-3-D registration method based on iterated optimal projection and applied it in a registration and reconstruction study of three transgenic mice. Compared with traditional registration methods based on the fixed points, our method was independent of the markers and the registration accuracy of the three experiments was improved by 0.3, 0.5, and 0.4 pixels, respectively. In addition, based on the above two registration results using the two registration methods, we reconstructed the 3-D location of the inner bioluminescent source in the three transgenic mice. The reconstruction results showed that the average error distance between the center of the reconstructed element and the center of the real element were reduced by 0.32, 0.48, and 0.39 mm, respectively.


Subject(s)
Optical Imaging/methods , X-Ray Microtomography/methods , Algorithms , Animals , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Luciferases/genetics , Luciferases/metabolism , Luminescent Measurements/statistics & numerical data , Mice , Mice, Transgenic , Optical Imaging/statistics & numerical data , Optical Phenomena , Osteocalcin/genetics , Osteocalcin/metabolism , Osteogenesis , Radiographic Image Interpretation, Computer-Assisted , X-Ray Microtomography/statistics & numerical data
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