scholarly journals Specificity and Diversity of Antibodies to Mycobacterium tuberculosis Arabinomannan

2003 ◽  
Vol 10 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Josephine Anne D. Navoa ◽  
Suman Laal ◽  
Liise-Anne Pirofski ◽  
Gary R. McLean ◽  
Zhongdong Dai ◽  
...  

ABSTRACT Arabinomannan (AM) is a polysaccharide antigen of the mycobacterial capsule. However, it is uncertain whether AM constitutes an immunologically distinct fraction of Mycobacterium tuberculosis. In this study, we analyzed the repertoire and specificity of antibodies to AM by using AM-binding murine monoclonal antibodies (MAbs) and human serum samples. Murine MAbs were found to be diverse in their specificity to AM and cross-reactivity with other arabinose-containing mycobacterial polysaccharides, with MAb 9d8 binding exclusively to AM. Human antibodies to AM were detected in serum samples from patients with pulmonary tuberculosis (TB), as well as in those from healthy, purified protein derivative-negative controls, with significantly higher titers among patients. The binding of human antibodies to AM was inhibited by MAb 9d8 in three patients with TB but not in controls. MAb 5c11, which recognizes other mycobacterial arabinose-containing carbohydrates in addition to AM, inhibited the binding of serum samples from 75% of patients and 76% of controls. Analysis of human antibodies with murine MAbs to human VH determinants demonstrated diversity among antibodies to AM with qualitative and quantitative differences compared with antibodies to lipoarabinomannan. In summary, our study suggests that antibodies to AM are diverse and heterogeneous with respect to antigen recognition and VH determinant expression, with human serum samples containing different subsets of antibodies to AM with the specificities of AM-binding murine MAbs. One MAb and a subset of human antibodies bind AM specifically, suggesting that this polysaccharide is antigenically distinct and is expressed in human infection.

2015 ◽  
Vol 20 (13) ◽  
Author(s):  
Y Qiu ◽  
C P Muller ◽  
K Van Reeth

Seroreactivity to H3N2 swine influenza viruses (SIVs) was evaluated in serum samples collected from 843 people aged 0 to 100 years in 2010 in Luxembourg. Sera were analysed by haemagglutination inhibition (HI) and virus neutralisation (VN) assays targeting a European H3N2 SIV, a North American H3N2 variant of swine origin (H3N2v) and human seasonal H3N2 viruses isolated in 1975, 1995 and 2005. HI antibodies (titre?≥?10) against European H3N2 SIV were almost exclusively detected in those born before 1990, of whom 70% were seropositive. HI antibodies against H3N2v were predominantly found in those born before 2000, with 86% seropositive. Titres against the North American H3N2v were higher than against the European H3N2 SIV. VN patterns were similar, but with higher rates and titres. We also demonstrated lower seroreactivity to European H3N2 SIV than to North American H3N2v virus. Finally, we found a strong correlation between HI titres against the European H3N2 SIV and H3N2v and their respective human ancestors, A/Victoria/3/75 and A/Nanchang/933/95. This finding and the minimal contacts between humans and pigs in Luxembourg suggest that anti-SIV antibodies in human serum samples reflect serological cross-reactivity with historical human H3N2 viruses. Our findings help assess the pandemic risk of H3N2 SIV.


2019 ◽  
Vol 15 (6) ◽  
pp. 678-684
Author(s):  
Biljana Nigović ◽  
Jakov Vlak

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.


1990 ◽  
Vol 126 (1) ◽  
pp. 159-168 ◽  
Author(s):  
A. N. Thakur ◽  
R. Coles ◽  
A. Sesay ◽  
B. Earley ◽  
H. S. Jacobs ◽  
...  

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


2009 ◽  
Vol 15 ◽  
pp. 232-234 ◽  
Author(s):  
E.M Mendes do Nascimento ◽  
S. Colombo ◽  
T.K. Nagasse-Sugahara ◽  
R.N. Angerami ◽  
M.R. Resende ◽  
...  

2016 ◽  
Vol 129 ◽  
pp. 205-212 ◽  
Author(s):  
Adrian Marcelo Granero ◽  
Gastón Darío Pierini ◽  
Sebastián Noel Robledo ◽  
María Susana Di Nezio ◽  
Héctor Fernández ◽  
...  

mSphere ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
Gregory R. Wiedman ◽  
Yanan Zhao ◽  
David S. Perlin

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.


2016 ◽  
Vol 8 (2) ◽  
pp. 249-255 ◽  
Author(s):  
B. L'Homme ◽  
J.-F. Focant

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.


2004 ◽  
Vol 516 (1-2) ◽  
pp. 135-140 ◽  
Author(s):  
José Luis Vı́lchez ◽  
Lilia Araujo ◽  
Avismelsi Prieto ◽  
Alberto Navalón

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