scholarly journals Evaluation of a New Immunochromatography Technology Test (LDBio Diagnostics) To Detect Toxoplasma IgG and IgM: Comparison with the Routine Architect Technique

2017 ◽  
Vol 55 (12) ◽  
pp. 3395-3404 ◽  
Author(s):  
Caroline Mahinc ◽  
Pierre Flori ◽  
Edouard Delaunay ◽  
Cécile Guillerme ◽  
Sana Charaoui ◽  
...  

ABSTRACTA study comparing the ICT (immunochromatography technology)ToxoplasmaIgG and IgM rapid diagnostic test (LDBio Diagnostics, France) with a fully automated system, Architect, was performed on samples from university hospitals of Marseille and Saint-Etienne. A total of 767 prospective sera and 235 selected sera were collected. The panels were selected to test various IgG and IgM parameters. The reference technique,ToxoplasmaIgGII Western blot analysis (LDBio Diagnostics), was used to confirm the IgG results, and commercial kits Platelia Toxo IgM (Bio-Rad) and Toxo-ISAgA (bioMérieux) were used in Saint-Etienne and Marseille, respectively, as the IgM reference techniques. Sensitivity and specificity of the ICT and the Architect IgG assays were compared using a prospective panel. Sensitivity was 100% for the ICT test and 92.1% for Architect (cutoff at 1.6 IU/ml). The low-IgG-titer serum results confirmed that ICT sensitivity was superior to that of Architect. Specificity was 98.7% (ICT) and 99.8% (Architect IgG). The ICT test is also useful for detecting IgM without IgG and is both sensitive (100%) and specific (100%), as it can distinguish nonspecific IgM from specificToxoplasmaIgM. In comparison, IgM sensitivity and specificity on Architect are 96.1% and 99.6%, respectively (cutoff at 0.5 arbitrary units [AU]/ml). To conclude, this new test overcomes the limitations of automated screening techniques, which are not sensitive enough for IgG and lack specificity for IgM (rare IgM false-positive cases).

2002 ◽  
Vol 97 (3) ◽  
pp. 668-675 ◽  
Author(s):  
Mahlon D. Johnson ◽  
Evelyn Okediji ◽  
Ann Woodard ◽  
Steven A. Toms ◽  
George S. Allen

Object. The intracellular events transducing mitogenic signals from platelet-derived growth factor—β (PDGFβ) receptor tyrosine kinases are not precisely known. In this study the authors evaluated whether the phosphatidylinositol 3-kinase (PI3-K)—Akt—p70S6K pathway is expressed in meningiomas, regulates their growth, and transduces mitogenic signals of PDGF-BB. Methods. Nine meningioma tumors obtained in humans were evaluated using Western blot analysis for phosphorylated (activated) Akt and phosphorylated p70S6K. Cells cultured from seven of these meningiomas were also screened using Western blot analysis for Akt and for phosphorylated Akt and p70S6K. The authors also evaluated whether PDGF-BB stimulation of meningioma cells was associated with the phosphorylation of Akt and p70S6K known to activate these kinases. In addition, the effects of wortmannin, an inhibitor of PI3-K, on proliferation and activation of Akt and p70S6K in meningioma cells stimulated with PDGF-BB were evaluated. Western blots of lysates from meningiomas demonstrated phosphorylated Akt and p70S6K. Treatment with PDGF-BB stimulated phosphorylation of Akt and p70S6K in each meningioma cell culture. Wortmannin (500 and 1000 nM) significantly decreased PDGF-BB stimulation of meningioma cells (p < 0.001) while it reduced Akt and p70S6K phosphorylation but not mitogen-activated protein kinase/extracellular signal—regulated kinase (MAPK/ERK) phosphorylation. Conclusions. These findings indicate that Akt and p70S6K are constitutively expressed and activated in meningioma cells and that the PI3-K—Akt—p70S6K pathway may participate in transduction of mitogenic signals in meningiomas independent of the Raf-1—MEK-1—MAPK/ERK cascade.


1994 ◽  
Vol 27 (3) ◽  
pp. 228
Author(s):  
A. Fortin ◽  
N. Berkova ◽  
S. Tremblay ◽  
F. Côté ◽  
F. Rousseau ◽  
...  

2013 ◽  
Vol 20 (4) ◽  
pp. 468-473 ◽  
Author(s):  
Nouha Chahed Bel-Ochi ◽  
Aïda Bouratbine ◽  
Mohamed Mousli

ABSTRACTSerologic detection ofToxoplasma gondiiIgG antibodies is widely accepted as a means to determine immune status and susceptibility toToxoplasmainfection during pregnancy. However, current commercial kits present some drawbacks, such as a requirement for whole-parasite antigen preparation or interassay variability. To address these problems, the purpose of this study was to produce a whole sequence of the recombinantT. gondiiSAG1 antigen (rSAG1) to assess its diagnostic performance inToxoplasmaIgG screening and to explore a saliva-based method as a noninvasive alternative to serum-based testing. rSAG1 was expressed in recombinant bacteria as inclusion bodies, purified through one-step affinity chromatography, and refolded in native form by dialysis. A large amount was obtained, and the specific antigen immunoreactivity was confirmed by immunoblotting. Two rSAG1-based enzyme-linked immunosorbent assays (ELISAs) applied to paired serum and saliva samples were designed. The rSAG1-based ELISA evaluation consisted of testing intrinsic sensitivity and specificity of 49 serum samples from patients immune to toxoplasmosis and 42 serum samples from nonimmune controls identified by routinely used kits. To assess agreement between serum-based and saliva-based tests, the positive percent agreement (PPA) and negative percent agreement (NPA) between the 2 tests were estimated. The rSAG1 serum-based ELISA detected specific IgG with 100% sensitivity and specificity. The PPA and NPA between the serum-based and saliva-based tests varied according to the selected optical density threshold in saliva. Thus, for a selected cutoff of 0.14, the PPA was 100% and the NPA was 88.1%, whereas for a selected cutoff of 0.29, the PPA was 67.3% and the NPA was 100%.


2015 ◽  
Vol 90 (5) ◽  
pp. 630-633 ◽  
Author(s):  
N. Nhancupe ◽  
E.V. Noormahomed ◽  
S. Afonso ◽  
K.I. Falk ◽  
J. Lindh

AbstractThe diagnosis of neurocysticercosis (NCC) requires expensive neuroimaging techniques that are seldom affordable for people in endemic countries. Accordingly, there is a need for new low-cost diagnostic methods that offer high sensitivity and specificity. In this study, we evaluated Western blot analysis of the previously described recombinant antigen Tsol-p27 in relation to a commercial or in-house enzyme-linked immunosorbent assay (ELISA) for NCC, and compared the results with those provided by a commercial enzyme-linked immunoelectrotransfer blot (EITB) assay, which was regarded as the reference standard method. The analysed serum samples were obtained from 165 people, 18 of whom were confirmed to be NCC positive by EITB. Comparing our Western blot analysis of Tsol-p27 with a previous evaluation performed in Central America showed similar specificity (96.69% versus 97.8%) and sensitivity (85.71% versus 86.7%). The present results indicate that the recombinant Tsol-p27 antigen provides good sensitivity and specificity, and might be preferable as a diagnostic antigen in poorly equipped laboratories in endemic countries.


2015 ◽  
Vol 81 (19) ◽  
pp. 6839-6849 ◽  
Author(s):  
Han-Lin Liu ◽  
Wei-Fang Lin ◽  
Wen-Chi Hu ◽  
Yung-An Lee ◽  
Ya-Chun Chang

ABSTRACTPotyviruses are major pathogens that often cause mixed infection in calla lilies. To reduce the time and cost of virus indexing, a detection method for the simultaneous targeting of multiple potyviruses was developed by generating a broad-spectrum monoclonal antibody (MAb) for detecting the greatest possible number of potyviruses. The conserved 121-amino-acid core regions of the capsid proteins ofDasheen mosaic potyvirus(DsMV),Konjak mosaic potyvirus(KoMV), andZantedeschia mild mosaic potyvirus(ZaMMV) were sequentially concatenated and expressed as a recombinant protein for immunization. After hybridoma cell fusion and selection, one stable cell line that secreted a group-specific antibody, named C4 MAb, was selected. In the reaction spectrum test, the C4 MAb detected at least 14 potyviruses by indirect enzyme-linked immunosorbent assay (I-ELISA) and Western blot analysis. Furthermore, the variable regions of the heavy (VH) and light (VL) chains of the C4 MAb were separately cloned and constructed as single-chain variable fragments (scFvs) for expression inEscherichia coli. Moreover, the pectate lyase E (PelE) signal peptide ofErwinia chrysanthemiS3-1 was added to promote the secretion of C4 scFvs into the medium. According to Western blot analysis and I-ELISA, the soluble C4 scFv (VL-VH) fragment showed a binding specificity similar to that of the C4 MAb. Our results demonstrate that a recombinant protein derived from fusion of the conserved regions of viral proteins has the potential to produce a broad-spectrum MAb against a large group of viruses and that the PelE signal peptide can improve the secretion of scFvs inE. coli.


2019 ◽  
Vol 58 (2) ◽  
Author(s):  
Chloé Le Roy ◽  
Cécile Bébéar ◽  
Sabine Pereyre

ABSTRACT As macrolide resistance in Mycoplasma genitalium is increasing worldwide, macrolide resistance-associated mutations should be assessed in M. genitalium-positive specimens. New commercial kits are available for detection of macrolide resistance concurrently with M. genitalium. We prospectively evaluated the handling and clinical performances of three commercial kits for detection of macrolide resistance in M. genitalium. Between August and December 2018, remnants of all urogenital specimens determined to be M. genitalium positive using an in-house real-time PCR assay were prospectively collected at the French National Reference Center for Bacterial Sexually Transmitted Infections, Bordeaux University Hospital, Bordeaux, France. The internal control of each kit was added to the primary specimen before DNA extraction, and the absence of amplification inhibition associated with the addition of the three internal controls was assessed. Specimens were evaluated with four assays: the ResistancePlus MG assay (SpeeDx), the S-DiaMGRes assay (Diagenode), the RealAccurate TVMGres assay (PathoFinder), and amplification and sequencing of the 23S rRNA gene (the reference assay). Overall, 195 M. genitalium-positive specimens were assessed. The positive agreement of M. genitalium detection for each kit ranged between 94.8% and 96.4%. Among 154 specimens with M. genitalium positivity as detected by the three commercial kits and 23S rRNA sequencing data, the clinical sensitivity and specificity ranges of the three commercial kits for detecting macrolide resistance-associated mutations were 95 to 100% and 94.6 to 97.3%, respectively. The sensitivity and specificity values were similar among the kits. The launch of three easy-to-use sensitive and specific commercial kits for simultaneous detection of M. genitalium and macrolide resistance will be useful for resistance-guided therapy.


1985 ◽  
Vol 60 (5) ◽  
pp. 1359-1366 ◽  
Author(s):  
M. Ivan ◽  
D. J. Buckley ◽  
G. St. Amour ◽  
C. F. Nicholls ◽  
D. M. Veira

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 228-235 ◽  
Author(s):  
Qiang Jia ◽  
Yanhe Li ◽  
Desheng Xu ◽  
Zhenjiang Li ◽  
Zhiyuan Zhang ◽  
...  

Object The authors sought to evaluate modification of the radiation response of C6 glioma cells in vitro and in vivo by inhibiting the expression of Ku70. To do so they investigated the effect of gene transfer involving a recombinant replication-defective adenovirus containing Ku70 short hairpin RNA (Ad-Ku70shRNA) combined with Gamma Knife treatment (GKT). Methods First, Ad-Ku70shRNA was transfected into C6 glioma cells and the expression of Ku70 was measured using Western blot analysis. In vitro, phenotypical changes in C6 cells, including proliferation, cell cycle modification, invasion ability, and apoptosis were evaluated using the MTT (3′(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazolium bromide) assay, Western blot analysis, and cell flow cytometry. In vivo, parental C6 cells transfected with Ad-Ku70shRNA were implanted stereotactically into the right caudate nucleus in Sprague-Dawley rats. After GKS, apoptosis was analyzed using the TUNEL (terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling) method. The inhibitory effects on growth and invasion that were induced by expression of proliferating cell nuclear antigen and matrix metalloproteinase–9 were determined using immunohistochemical analyses. Results The expression of Ku70 was clearly inhibited in C6 cells after transfection with Ad-Ku70shRNA. In vitro following transfection, the C6 cells showed improved responses to GKT, including suppression of proliferation and invasion as well as an increased apoptosis index. In vivo following transfection of Ad-Ku70shRNA, the therapeutic efficacy of GKT in rats with C6 gliomas was greatly enhanced and survival times in these animals were prolonged. Conclusions Our data support the potential for downregulation of Ku70 expression in enhancing the radiosensitivity of gliomas. The findings of our study indicate that targeted gene therapy–mediated inactivation of Ku70 may represent a promising strategy in improving the radioresponsiveness of gliomas to GKT.


2020 ◽  
Vol 20 (23) ◽  
pp. 2070-2079
Author(s):  
Srimadhavi Ravi ◽  
Sugata Barui ◽  
Sivapriya Kirubakaran ◽  
Parul Duhan ◽  
Kaushik Bhowmik

Background: The importance of inhibiting the kinases of the DDR pathway for radiosensitizing cancer cells is well established. Cancer cells exploit these kinases for their survival, which leads to the development of resistance towards DNA damaging therapeutics. Objective: In this article, the focus is on targeting the key mediator of the DDR pathway, the ATM kinase. A new set of quinoline-3-carboxamides, as potential inhibitors of ATM, is reported. Methods: Quinoline-3-carboxamide derivatives were synthesized and cytotoxicity assay was performed to analyze the effect of molecules on different cancer cell lines like HCT116, MDA-MB-468, and MDA-MB-231. Results: Three of the synthesized compounds showed promising cytotoxicity towards a selected set of cancer cell lines. Western Blot analysis was also performed by pre-treating the cells with quercetin, a known ATM upregulator, by causing DNA double-strand breaks. SAR studies suggested the importance of the electron-donating nature of the R group for the molecule to be toxic. Finally, Western-Blot analysis confirmed the down-regulation of ATM in the cells. Additionally, the PTEN negative cell line, MDA-MB-468, was more sensitive towards the compounds in comparison with the PTEN positive cell line, MDA-MB-231. Cytotoxicity studies against 293T cells showed that the compounds were at least three times less toxic when compared with HCT116. Conclusion: In conclusion, these experiments will lay the groundwork for the evolution of potent and selective ATM inhibitors for the radio- and chemo-sensitization of cancer cells.


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