Analysis of Entamoeba histolytica Excretory-Secretory Antigen and Identification of a New Potential Diagnostic Marker

ABSTRACTSerodiagnosis of amoebiasis remains the preferred method for diagnosis of amoebic liver abscess (ALA). However, the commercially available kits are problematic in areas of endemicity due to the persistently high background antibody titers. Human serum samples (n= 38) from patients with ALA who live in areas of endemicity were collected from Hospital Universiti Sains Malaysia during the period of 2008 to 2010. Western blots using excretory-secretory antigen (ESA) collected from axenically grownEntamoeba histolyticawere probed with the above serum samples. Seven antigenic proteins of ESA with various reactivities were identified, i.e., 152 kDa, 131 kDa, 123 kDa, 110 kDa, 100 kDa, 82 kDa, and 76 kDa. However, only the 152-kDa and 110-kDa proteins showed sensitivities above 80% in the Western blot analysis. All the antigenic proteins showed undetectable cross-reactivity when probed with healthy human serum samples (n= 30) and serum samples from other infections (n= 33). From the matrix-assisted laser desorption ionization–two-stage time of flight (MALDI-TOF/TOF) analysis, the proteins were identified as heavy subunits ofE. histolyticalectin andE. histolyticapyruvate phosphate dikinase, respectively. Use of theE. histolyticalectin for diagnosis of ALA has been well reported by researchers and is being used in commercialized kits. However, this is the first report on the potential use of pyruvate phosphate dikinase for diagnosis of ALA; thus, this molecule merits further evaluation on its diagnostic value using a larger panel of serum samples.

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Peptide Microarray Analysis ofIn Silico-Predicted Epitopes for Serological Diagnosis of Toxoplasma gondii Infection in Humans

Clinical and Vaccine Immunology ◽

10.1128/cvi.00119-12 ◽

2012 ◽

Vol 19 (6) ◽

pp. 865-874 ◽

Cited By ~ 27

Author(s):

Pavlo Maksimov ◽

Johannes Zerweck ◽

Aline Maksimov ◽

Andrea Hotop ◽

Uwe Groß ◽

...

Keyword(s):

Toxoplasma Gondii ◽

Human Serum ◽

Clinical Symptoms ◽

Serological Diagnosis ◽

Ocular Toxoplasmosis ◽

Serum Samples ◽

Peptide Microarray ◽

Content Type ◽

Human Serum Samples ◽

Diagnostic Potential

ABSTRACTToxoplasma gondiiinfections occur worldwide in humans and animals. In immunocompromised or prenatally infected humans,T. gondiican cause severe clinical symptoms. The identification of specific epitopes onT. gondiiantigens is essential for the improvement and standardization of the serological diagnosis of toxoplasmosis. We selected 20 peptides mimicking linear epitopes on GRA1, GRA2, GRA4, and MIC3 antigenicT. gondiiproteinsin silicousing the software ABCpred. A further 18 peptides representing previously published epitopes derived from GRA1, SAG1, NTPase1, and NTPase2 antigens were added to the panel. A peptide microarray assay was established to prove the diagnostic performance of the selected peptides with human serum samples. Seropositive human serum samples (n= 184) were collected from patients presenting with acute toxoplasmosis (n= 21), latentT. gondiiinfection (n= 53), and inactive ocular toxoplasmosis (n= 10) and from seropositive forest workers (n= 100). To adjust the cutoff values for each peptide, sera from seronegative forest workers (n= 75) and patients (n= 65) were used. Univariate logistic regression suggested the significant diagnostic potential of eight novel and two previously published peptides. A test based on these peptides had an overall diagnostic sensitivity of 69% (100% in ocular toxoplasmosis patients, 86% in acutely infected patients, 81% in latently infected patients, and 57% in seropositive forest workers). The analysis of seronegative sera performed with these peptides revealed a diagnostic specificity of 84%. The results of our study suggest that the use of a bioinformatic approach for epitope prediction in combination with peptide microarray testing is a powerful method for the selection ofT. gondiiepitopes as candidate antigens for serological diagnosis.

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Simultaneous Monitoring of Febuxostat and Uric Acid in Human Serum Samples Using the Direct Square-Wave Voltammetric Method

Current Analytical Chemistry ◽

10.2174/1573411014666180730112905 ◽

2019 ◽

Vol 15 (6) ◽

pp. 678-684

Author(s):

Biljana Nigović ◽

Jakov Vlak

Keyword(s):

Uric Acid ◽

Human Serum ◽

Oxidase Inhibitor ◽

Serum Samples ◽

Boron Doped Diamond ◽

Fast Analysis ◽

Xanthine Oxidase Inhibitor ◽

Voltammetric Method ◽

Square Wave ◽

Human Serum Samples

Background: High uric acid serum level, hyperuricemia, is now associated with many diseases such as gout, chronic kidney disease, hypertension, coronary artery disease and diabetes. Febuxostat is a novel selective xanthine oxidase inhibitor approved for the treatment of hyperuricemia. Objective: The aim of this study was to develop a first analytical method for the simultaneous determination of febuxostat and uric acid. Methods: An unmodified boron-doped diamond electrode provided concurrent quantitation of drug at low levels and uric acid, which has clinical significance in the diagnosis and therapy of hyperuricemia, at relatively high concentrations. The direct square-wave voltammetric method was applied to the analysis of both analytes in human serum samples. Results: Under the optimized conditions, the linear response of peak current on febuxostat concentration was achieved in the range from 7.5 × 10-7 to 3 × 10-5 M, while uric acid showed two linear ranges of 5 × 10-6 - 5 × 10-5 M and 5 × 10-5 - 2 × 10-4 M. The method was successfully utilised for quantification of both analytes in human serum samples. Good recoveries were obtained without interference from common inorganic cations and anions as well as glucose, dopamine, ascorbic and folic acids at concentrations expected in physiological conditions. Conclusion: The great benefits of developed method are fast analysis (only 7.5 s for run), low cost and simplicity of performance.

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Dual-readout test strips platform for portable and highly sensitive detection of alkaline phosphatase in human serum samples

Chinese Chemical Letters ◽

10.1016/j.cclet.2021.05.019 ◽

2021 ◽

Author(s):

Juanzu Liu ◽

Hongmin Meng ◽

Lin Zhang ◽

Shasha Li ◽

Juan Chen ◽

...

Keyword(s):

Alkaline Phosphatase ◽

Human Serum ◽

Sensitive Detection ◽

Serum Samples ◽

Test Strips ◽

Human Serum Samples ◽

Highly Sensitive ◽

Highly Sensitive Detection

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A rat granulosa cell plasminogen activator bioassay for FSH in human serum

Journal of Endocrinology ◽

10.1677/joe.0.1260159 ◽

1990 ◽

Vol 126 (1) ◽

pp. 159-168 ◽

Cited By ~ 7

Author(s):

A. N. Thakur ◽

R. Coles ◽

A. Sesay ◽

B. Earley ◽

H. S. Jacobs ◽

...

Keyword(s):

Human Serum ◽

Plasminogen Activator ◽

Granulosa Cell ◽

Serum Samples ◽

Glycoprotein Hormone ◽

Assay Sensitivity ◽

Serum Factors ◽

Human Serum Samples ◽

Heat Treated ◽

Fsh Bioactivity

ABSTRACT A previously described in-vitro rat granulosa cell plasminogen activator bioassay for FSH has been modified and applied in the assay of human serum. This modified method consists of exposing the diethylstilboestrol-stimulated granulosa cells from 25- to 26-day-old rats to FSH or test substance for 3·5 h in wells coated with 125I-labelled fibrinogen and treated with thrombin. Following stimulation with FSH, the dose-related production of plasminogen activator was measured as the degree of 125I-labelled fibrinolysis in the presence of added plasminogen. Using the urinary FSH/LH bioassay reference preparation as the assay standard, the useful range of the assay was 0·3–15IU/l, with an assay sensitivity of 0·3 IU/l. As determined using purified glycoprotein hormone preparations, the assay was highly specific for FSH. The minor degree of FSH bioactivity measured in some of the hormone preparations was accounted for by the amount of FSH contamination in these preparations. To abolish interference caused by unknown serum factors, we heat-treated the serum samples for 15 min at 56 °C before the assay. The results indicated that neither immunoreactivity nor bioactivity was affected by this treatment. Furthermore, heat-treated human sera gave responses parallel to the standard curve at the three dose levels (2, 4 and 8 μl) studied. We used this bioassay to estimate the FSH-like bioactivity in 15 human serum samples. The estimates of immunoreactive FSH in these samples correlated well with the corresponding FSH bioactivity (r = 0·745, n = 15 and P < 0·05). The results indicate that with this sensitive and rapid (completed within 24 h) bioassay, it should be possible to measure FSH bioactivity in heat-treated human serum samples. Journal of Endocrinology (1990) 126, 159–168

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Evaluation of PCR-based assay in human serum samples for diagnosis of fatal cases of spotted fever group rickettsiosis

Clinical Microbiology and Infection ◽

10.1111/j.1469-0691.2008.02153.x ◽

2009 ◽

Vol 15 ◽

pp. 232-234 ◽

Cited By ~ 8

Author(s):

E.M Mendes do Nascimento ◽

S. Colombo ◽

T.K. Nagasse-Sugahara ◽

R.N. Angerami ◽

M.R. Resende ◽

...

Keyword(s):

Human Serum ◽

Spotted Fever ◽

Spotted Fever Group ◽

Serum Samples ◽

Human Serum Samples

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Simultaneous determination of ascorbic and uric acids and dopamine in human serum samples using three-way calibration with data from square wave voltammetry

Microchemical Journal ◽

10.1016/j.microc.2016.07.004 ◽

2016 ◽

Vol 129 ◽

pp. 205-212 ◽

Cited By ~ 16

Author(s):

Adrian Marcelo Granero ◽

Gastón Darío Pierini ◽

Sebastián Noel Robledo ◽

María Susana Di Nezio ◽

Héctor Fernández ◽

...

Keyword(s):

Human Serum ◽

Simultaneous Determination ◽

Square Wave Voltammetry ◽

Serum Samples ◽

Square Wave ◽

Human Serum Samples ◽

Wave Voltammetry

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A Novel, Rapid, and Low-Volume Assay for Therapeutic Drug Monitoring of Posaconazole and Other Long-Chain Azole-Class Antifungal Drugs

mSphere ◽

10.1128/msphere.00623-18 ◽

2018 ◽

Vol 3 (6) ◽

Cited By ~ 2

Author(s):

Gregory R. Wiedman ◽

Yanan Zhao ◽

David S. Perlin

Keyword(s):

Liquid Chromatography ◽

Therapeutic Drug Monitoring ◽

Human Serum ◽

Drug Monitoring ◽

Fungal Infections ◽

Antifungal Drugs ◽

Therapeutic Drug ◽

Serum Samples ◽

Human Serum Samples ◽

Long Chain

ABSTRACT Clinicians need a better way to accurately monitor the concentration of antimicrobials in patient samples. In this report, we describe a novel, low-sample-volume method to monitor the azole-class antifungal drug posaconazole, as well as certain other long-chain azole-class antifungal drugs in human serum samples. Posaconazole represents an important target for therapeutic drug monitoring (TDM) due to its widespread use in treating invasive fungal infections and well-recognized variability of pharmacokinetics. The current “gold standard” requires trough and peak monitoring through high-pressure liquid chromatography (HPLC) or liquid chromatography-tandem mass spectroscopy (LC-MS/MS). Other methods include bioassays that use highly susceptible strains of fungi in culture plates or 96-well formats to monitor concentrations. Currently, no method exists that is both highly accurate in detecting free drug concentrations and is also rapid. Herein, we describe a new method using reduced graphene oxide (rGO) and a fluorescently labeled aptamer, which can accurately assess clinically relevant concentrations of posaconazole and other long-chain azole-class drugs in little more than 1 h in a total volume of 100 µl. IMPORTANCE This work describes an effective assay for TDM of long-chain azole-class antifungal drugs that can be used in diluted human serum samples. This assay will provide a quick, cost-effective method for monitoring concentrations of drugs such as posaconazole that exhibit well-documented pharmacokinetic variability. Our rGO-aptamer assay has the potential to improve health care for those struggling to treat fungal infections in rural or resource-limited setting.

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Cryogenic zone compression GC-HRTOFMS for the measurement of PCB-153 and DDE in 20 μL serum samples

Analytical Methods ◽

10.1039/c5ay00543d ◽

2016 ◽

Vol 8 (2) ◽

pp. 249-255 ◽

Cited By ~ 1

Author(s):

B. L'Homme ◽

J.-F. Focant

Keyword(s):

Human Serum ◽

Human Exposure ◽

Proof Of Concept ◽

Serum Samples ◽

Human Serum Samples

Human exposure to POPs is of concern and typical biomonitoring studies require large amounts of blood (5–75 mL) from participants. As a proof of concept, we developed a miniaturized method based on MEPS and CZC applied to GC-HRTOFMS for the measurement of markers of exposure (PCB-153, DDE) in 20 μL human serum samples.

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