Amyloid-beta peptide affects viability and differentiation of embryonic and adult rat hippocampal progenitor cells

Neural stem cells (NSCs) have received recent attention due to their potential use in transplantation therapy for a number of neurological diseases. The Alzheimer\u27s Disease (AD) brain is a uniquely challenging environment for transplanted cells due to the presence of amyloid-beta (A[beta]) peptide, which is known to be toxic to neurons. The effects of A[beta] on NSCs have just recently begun to be investigated. Here, we examine the effect of A[beta] 25-35 on hippocampal progenitor cells (HPCs) from embryonic and adult rat. We also examine the effect of the tripeptide Gly-Pro-Arg (GPR) which has been reported to rescue primary culture neurons from A[beta]-induced toxicity. HPCs exposed to A[beta] in culture showed decreased viability as measured by MTT mitochondrial dehydrogenase assay; GPR was not protective against A[beta]-induced viability loss. A[beta] affected differentiation of adult, but not embryonic HPCs; adult HPCs exposed to A[beta] expressed the neural stem cell marker Nestin at higher levels than did controls. A[beta] did not affect proliferation of embryonic HPCs, although GPR did suppress embryonic HPC proliferation. A[beta] also did not show differential effects on proliferating neurons or glia, as determined by colabeling of BrdU and the neuronal marker MAP2 or the astrocytic marker GFAP. Our findings suggest that A[beta] decreases viability and affects differentiation of neural progenitor cells; however, specific effects upon neurogenesis or NPC proliferation were not seen

Clinical performance of the Elecsys electrochemiluminescent immunoassay for the detection of SARS-CoV-2 total antibodies

SCOPUS: le.jinfo:eu-repo/semantics/publishe

Clinical performance of the Panbio assay for the detection of SARS‐CoV‐2 IgM and IgG in COVID‐19 patients

Following the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, numerous serological tests have been developed, including rapid diagnostic tests. This study aims at assessing the clinical performance of the Panbio immunoglobulin G (IgG)/IgM coronavirus disease 2019 (COVID-19) test (Abbott), a rapid lateral flow assay for the qualitative detection of IgG and IgM against SARS-CoV-2. One hundred and thirty-eight samples from 95 COVID-19 patients with a positive SARS-CoV-2 reverse-transcriptase polymerase chain reaction were analyzed to assess the clinical sensitivity. Seventy-six pre-COVID-19 samples were used to evaluate the clinical specificity. Two independent and blinded raters determined visually the presence or absence of the IgG, IgM, and control lines for each test after 10 and 20 min. The sensitivity obtained from collected samples more than 14 days after the onset of symptoms was 95.2% for IgG. IgM was less frequently detected (highest sensitivity of 20.5%). The specificities obtained were 98.7% and 100% for IgG and IgM, respectively. In addition, the sensitivity of the assay was better when the reading was performed at 20 min than at 10 min, whereas the specificity was unchanged. The Panbio COVID-19 IgG/IgM rapid test detects IgG with high sensitivity 14 days since symptom onset but presents a low sensitivity for IgM. The specificity was excellent for both IgG and IgM.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Intraoperative flow measurements in gastroepiploic grafts using pulsed Doppler 1

Abstract Objective: The patency of a pedicled right gastroepiploic artery (RGEA) graft can be compromised by intraoperative twists, kinks or spasms. Therefore, a systematic flow assessment was made in RGEA grafts and was compared with similar measurements made in other types of bypass conduits. Methods: Intraoperative pulsed Doppler flowmeter measurements obtained in a series of 556 consecutive patients undergoing at least one coronary bypass grafting onto the right coronary system were studied. Eighty-five RGEA grafts were compared with 1427 bypass grafts implanted in the same group of patients and consisted of the following conduits: 442 left internal mammary (LIMA), 149 right internal mammary (RIMA), 831 greater saphenous vein (GSV) and five inferior epigastric (EPIG) grafts. Sequential grafts were excluded from the analysis. Results: Flow measurements and Doppler waveforms were abnormal and required graft repositioning, and the addition of a distal graft or intragraft papaverine injection (only in GSVs) in 29 cases (2.0% of all grafts). These graft corrections were necessary in 5.9% RGEAs, 3.4% LIMAs, 2.0% RIMAs, and 0.7% GSVs (P Ͻ 0.001). The relative risk for graft correction was eight times higher for RGEAs than for GSVs (P = 0.002). Flow increased from 8 ± 2 to 54 ± 5 ml/min (P Ͻ 0.0001). Flow data were significantly influenced by the type of run-off bed (P Ͻ 0.001), the measurements obtained in grafts implanted onto the right coronary artery and the left anterior descending artery being superior. Flows in RGEAs, however, were comparable with values obtained in other grafts implanted onto the same recipient coronary artery. Conclusions: A significantly higher incidence of graft malpositioning caused inadequate flows in RGEAs. However, normal flow values could be restored simply by assigning a better graft orientation under pulsed Doppler flowmeter control. Overall flow capacity of the RGEA did not differ from values obtained in other arterial and venous grafts implanted onto the same recipient arteries

High clinical performance and quantitative assessment of antibody kinetics using a dual recognition assay for the detection of SARS-CoV-2 IgM and IgG antibodies

Objectives: Several serological SARS-CoV-2 immunoassays have been developed recently but require external validation before widespread use. This study aims at assessing the analytical and clinical performance of the iFlash® anti-SARS-CoV-2 chemiluminescence assay for the detection of both IgM and IgG antibodies. The kinetics of the antibody response was also evaluated. Design & Methods: The precision, carry-over, linearity, limit of blank, detection and quantification were assessed. Sensitivity analysis was performed by using 178 sera collected from 154 RT-PCR confirmed COVID-19 patients. The specificity analysis was performed from 75 selected non-SARS-CoV-2 sera with a potential cross-reaction to the SARS-CoV-2 immunoassay. Results: This iFlash® SARS-CoV-2 assay showed excellent analytical performance. After 2 weeks since symptom onset, the sensitivities for IgM and IgG were 62.2% (95% CI: 52.3–71.2%) and 92.9%% (95% CI: 85.7–96.7%), respectively by using the cut-off provided by the manufacturer. After cut-off optimization (i.e. >2.81 for IgM and >4.86 for IgG), the sensitivity for IgM and IgG were 81.6 (95% CI: 72.7–88.1%) and 95.9% (95% CI: 89.4–98.7%), respectively. Optimized cut-off for IgG improved the sensitivity to reach 100% (95%CI: 87.6–100) from 28 days since symptom onset. Conclusions: This study shows that the iFlash® SARS-CoV-2 assay from YHLO biotechnology, has satisfactory analytical performance. Nevertheless, the sensitivity of the IgM is limited for a proper clinical use compared to IgG. The determination of anti-SARS-CoV-2 IgG antibodies from 28 days since symptom onset was associated with high sensitivity, especially using optimized cut-offs (i.e. 100%).SCOPUS: ar.jinfo:eu-repo/semantics/publishe

An Original ELISA-Based Multiplex Method for the Simultaneous Detection of 5 SARS-CoV-2 IgG Antibodies Directed against Different Antigens

Strategies to detect SARS-CoV-2 are increasingly being developed. Among them, serological methods have been developed. Nevertheless, although these may present an interesting clinical performance, they are often directed against only one antigen. This study aims at evaluating the clinical performance of an innovative multiplex immunoassay (i.e. CoViDiag assay) detecting simultaneously the presence of antibodies directed against N, S1, S2, RBD and NTD antigens. Sensitivity was evaluated in 135 samples obtained from 94 rRT-PCR confirmed coronavirus disease 2019 (COVID-19) patients. Non-SARS-CoV-2 sera (n = 132) collected before the COVID-19 pandemic with potential cross-reactions to the SARS-CoV-2 immunoassay were included in the specificity analysis. The antibody signature was also studied in hospitalized and non-hospitalized patients. The specificity of the CoViDiag assay was excellent for all antibodies (99.2 to 100%) using adapted cut-offs. None of the false positive samples were positive for more than one antibody. The sensitivity obtained from samples collected 14 days since symptom onset varied from 92.0 to 100.0% depending on the antibody considered. Among samples collected more than 14 days after symptom onset, 12.8, 66.3, 3.5, 9.3, 5.8 and 2.3% were positive for 5, 4, 3, 2, 1 or 0 antibodies, respectively. A trend toward higher antibody titers was observed in hospitalized patient in the early days since symptom onset. However, no significant difference was observed compared to non-hospitalized patients after 14 days since symptom onset. The clinical performance of the CoViDiag 5 IgG assay is sufficient to recommend its use for the detection and the characterization of the antibody signature following SARS-CoV-2 infection. The combination of several antigens in the same test improves the overall specificity and sensitivity of the test. Further research is needed to investigate whether this strategy may be of interest to identify severe disease outcome in patients with SARS-CoV-2 infection.SCOPUS: ar.jinfo:eu-repo/semantics/publishe