To evaluate the diagnostic performance of seven rapid IgG/IgM tests and the Euroimmun IgA/IgG ELISA for antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in COVID-19 ...patients.
Specificity was evaluated in 103 samples collected before January 2020. Sensitivity and time to seropositivity was evaluated in 167 samples from 94 patients with COVID-19 confirmed with RT-PCR on nasopharyngeal swab.
Specificity (confidence interval) of lateral flow assays (LFAs) was ≥91.3% (84.0–95.5) for IgM, ≥90.3% (82.9–94.8) for IgG, and ≥85.4% (77.2–91.1) for the combination IgM OR IgG. Specificity of the ELISA was 96.1% (90.1–98.8) for IgG and only 73.8% (64.5–81.4) for IgA. Sensitivity 14–25 days after the onset of symptoms was between ≥92.1% (78.5–98.0) and 100% (95.7–100) for IgG LFA compared to 89.5% (75.3–96.4) for IgG ELISA. Positivity of IgM OR IgG for LFA resulted in a decrease in specificity compared to IgG alone without a gain in diagnostic performance, except for VivaDiag. The results for IgM varied significantly between the LFAs with an average overall agreement of only 70% compared to 89% for IgG. The average dynamic trend to seropositivity for IgM was not shorter than for IgG. At the time of hospital admission the sensitivity of LFA was <60%.
Sensitivity for the detection of IgG antibodies 14–25 days after the onset of symptoms was ≥92.1% for all seven LFAs compared to 89.5% for the IgG ELISA. The results for IgM varied significantly, and including IgM antibodies in addition to IgG for the interpretation of LFAs did not improve the diagnostic performance.
Abstract
STUDY QUESTION
Are meiotic and developmental competence of human oocytes from small (2–8 mm) antral follicles improved by applying an optimized IVM method involving a prematuration step in ...presence of C-Type Natriuretic Peptide (CNP) followed by a maturation step in presence of FSH and Amphiregulin (AREG)?
SUMMARY ANSWER
A strategy involving prematuration culture (PMC) in the presence of CNP followed by IVM using FSH + AREG increases oocyte maturation potential leading to a higher availability of Day 3 embryos and good-quality blastocysts for single embryo transfer.
WHAT IS KNOWN ALREADY
IVM is a minimal-stimulation ART with reduced hormone-related side effects and risks for the patients, but the approach is not widely used because of an efficiency gap compared to conventional ART. In vitro systems that enhance synchronization of nuclear and cytoplasmic maturation before the meiotic trigger are crucial to optimize human IVM systems. However, previous PMC attempts have failed in sustaining cumulus-oocyte connections throughout the culture period, which prohibited a normal cumulus-oocyte communication and precluded an adequate response by the cumulus-oocyte complex (COC) to the meiotic trigger.
STUDY DESIGN, SIZE, DURATION
A first prospective study involved sibling oocytes from a group of 15 patients with polycystic ovary syndrome (PCOS) to evaluate effects of a new IVM culture method on oocyte nuclear maturation and their downstream developmental competence. A second prospective study in an additional series of 15 women with polycystic ovaries characterized and fine-tuned the culture conditions.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Fifteen women with PCOS (according to Rotterdam criteria) underwent IVM treatment after 3–5 days of highly purified human menopausal gonadotropin (HP-hMG) stimulation and no human chorionic gonadotropin (hCG) trigger before oocyte retrieval. A first study was designed with sibling oocytes to prospectively evaluate the impact of an IVM culture method: 24 h PMC with CNP + 30 h IVM with FSH and AREG, on embryo yield, in comparison to the standard (30 h) IVM clinical protocol (Group I, n = 15).
A second prospective study was performed in 15 women with polycystic ovaries, to characterize and optimize the PMC conditions (Group II, n = 15). The latter study involved the evaluation of oocyte meiotic arrest, the preservation of cumulus-oocyte transzonal projections (TZPs), the patterns of oocyte chromatin configuration and cumulus cells apoptosis following the 24 and 46 h PMC. Furthermore, oocyte developmental potential following PMC (24 and 46 h) + IVM was also evaluated. The first 20 good-quality blastocysts from PMC followed by IVM were analysed by next generation sequencing to evaluate their aneuploidy rate.
MAIN RESULTS AND THE ROLE OF CHANCE
PMC in presence of CNP followed by IVM using FSH and AREG increased the meiotic maturation rate per COC to 70%, which is significantly higher than routine standard IVM (49%; P ≤ 0.001). Hence, with the new system the proportion of COCs yielding transferable Day 3 embryos and good-quality blastocysts increased compared to routine standard IVM (from 23 to 43%; P ≤ 0.001 and from 8 to 18%; P ≤ 0.01, respectively). CNP was able to prevent meiosis resumption for up to 46 h. After PMC, COCs had preserved cumulus-oocyte TZPs. The blastocysts obtained after PMC + IVM did not show increased aneuploidy rates as compared to blastocysts from conventional ART.
LIMITATIONS REASONS FOR CAUTION
The novel IVM approach in PCOS patients was tested in oocytes derived from small antral follicles which have an intrinsically low developmental potential. Validation of the system would be required for COCs from different (larger) follicular sizes, which may involve further adjustment of PMC conditions. Furthermore, considering that this is a novel strategy in human IVM treatment, its global efficiency needs to be confirmed in large prospective randomized controlled trials. The further application in infertile patients without PCOS, e.g. cancer patients, remains to be evaluated.
WIDER IMPLICATIONS OF THE FINDINGS
The findings of this pilot study suggest that the efficiency gap between IVM and conventional IVF can be reduced by fine-tuning of the culture methods. This novel strategy opens new perspectives for safe and patient-friendly ART in patients with PCOS.
STUDY FUNDING/COMPETING INTEREST(S)
IVM research at the Vrije Universiteit Brussel has been supported by grants from: the Institute for the Promotion of Innovation by Science and Technology in Flanders (Agentschap voor Innovatie door Wetenschap en Technologie—IWT, project 110680); the Fund for Research Flanders (Fonds Wetenschappelijk Onderzoek–Vlaanderen—FWO, project G.0343.13), the Belgian Foundation Against Cancer (HOPE project, Dossier C69). The authors have no conflicts of interest.
We report on chloroquine, a 4-amino-quinoline, as an effective inhibitor of the replication of the severe acute respiratory syndrome coronavirus (SARS-CoV) in vitro. Chloroquine is a clinically ...approved drug effective against malaria. We tested chloroquine phosphate for its antiviral potential against SARS-CoV-induced cytopathicity in Vero E6 cell culture. Results indicate that the IC
50 of chloroquine for antiviral activity (8.8
±
1.2
μM) was significantly lower than its cytostatic activity; CC
50 (261.3
±
14.5
μM), yielding a selectivity index of 30. The IC
50 of chloroquine for inhibition of SARS-CoV in vitro approximates the plasma concentrations of chloroquine reached during treatment of acute malaria. Addition of chloroquine to infected cultures could be delayed for up to 5
h postinfection, without an important drop in antiviral activity. Chloroquine, an old antimalarial drug, may be considered for immediate use in the prevention and treatment of SARS-CoV infections.
The prior diagnosis of fatal astrocytoma in a 60-year-old man with Crohn's disease treated with natalizumab, a monoclonal antibody against alpha4 integrins, was reclassified as JC virus-related ...progressive multifocal leukoencephalopathy (PML). Analysis of frozen serum samples showed that JC virus DNA had appeared in the serum three months after the initiation of open-label natalizumab monotherapy and two months before the appearance of symptomatic PML. There was staining of the brain lesion for polyomavirus. This case report, along with two others, suggests that anti-alpha4-integrin therapy can result in JC virus-induced PML.
Introduction:
COVID-19 Ag Respi-Strip, an immunochromatographic (ICT) assay for the rapid detection of SARS-CoV-2 antigen on nasopharyngeal specimen, has been developed to identify positive COVID-19 ...patients allowing prompt clinical and quarantine decisions. In this original research article, we describe the conception, the analytical and clinical performances as well as the risk management of implementing the COVID-19 Ag Respi-Strip in a diagnostic decision algorithm.
Materials and Methods:
Development of the COVID-19 Ag Respi-Strip resulted in a ready-to-use ICT assay based on a membrane technology with colloidal gold nanoparticles using monoclonal antibodies directed against the SARS-CoV and SARS-CoV-2 highly conserved nucleoprotein antigen. Four hundred observations were recorded for the analytical performance study and thirty tests were analyzed for the cross-reactivity study. The clinical performance study was performed in a retrospective multi-centric evaluation on aliquots of 328 nasopharyngeal samples. COVID-19 Ag Respi-Strip results were compared with qRT-PCR as golden standard for COVID-19 diagnostics.
Results:
In the analytical performance study, the reproducibility showed a between-observer disagreement of 1.7%, a robustness of 98%, an overall satisfying user friendliness and no cross-reactivity with other virus-infected nasopharyngeal samples. In the clinical performance study performed in three different clinical laboratories during the ascendant phase of the epidemiological curve, we found an overall sensitivity and specificity of 57.6 and 99.5%, respectively with an accuracy of 82.6%. The cut-off of the ICT was found at CT <22. User-friendliness analysis and risk management assessment through Ishikawa diagram demonstrate that COVID-19 Ag Respi-Strip may be implemented in clinical laboratories according to biosafety recommendations.
Conclusion:
The COVID-19 Ag Respi-Strip represents a promising rapid SARS-CoV-2 antigen assay for the first-line diagnosis of COVID-19 in 15 min at the peak of the pandemic. Its role in the proposed diagnostic algorithm is complementary to the currently-used molecular techniques.
Rotaviruses (RVs) are responsible for more than 600,000 child deaths each year. The worldwide introduction of two life oral vaccines RotaTeq and Rotarix is believed to reduce this number ...significantly. Before the licensing of both vaccines, two new genotypes, G9 and G12, emerged in the human population and were able to spread across the entire globe in a very short time span. To quantify the VP7 mutation rates of these G9 and G12 genotypes and to estimate their most recent common ancestors, we used a Bayesian Markov chain Monte Carlo framework. Based on 356 sequences for G9 and 140 sequences for G12, we estimated mutation rates (nt substitutions/site/year) of 1.87 × 10(-3) (1.45-2.27 × 10(-3)) for G9 and 1.66 × 10(-3) (1.13-2.32 × 10(-3)) for G12. For both the G9 and G12 strains, one particular (sub) lineage was able to disseminate and cause disease across the world. The most recent common ancestors of these particular lineages were dated back to 1989 (1986-1992) and 1995 (1992-1998) for the G9 and G12 genotypes, respectively. These estimates suggest that a single novel RV (e.g., a vaccine escape mutant) can spread worldwide in little more than a decade. These results re-emphasize the need for thorough and continued RV surveillance in order to detect such potential spreading events at an early stage.
Purpose
To investigate the effectiveness of a biphasic IVM culture strategy at improving IVM outcomes in oocytes from small follicles (< 6 mm) compared with routine Standard IVM in patients with ...polycystic ovaries.
Methods
This prospective pilot study was performed in 40 women with polycystic ovaries whose oocytes were randomized to two IVM culture methods. Patients received a total stimulation dose of 450 IU rFSH. Cumulus-oocyte complexes (COCs) from follicles < 6 mm and ≥ 6 mm were retrieved and cultured separately in either a prematuration medium with c-type natriuretic peptide followed by IVM (CAPA-IVM), or STD-IVM. Primary outcomes were maturation rate, embryo quality, and the number of vitrified day 3 embryos per patient.
Results
Use of the CAPA-IVM system led to a significant improvement in oocyte maturation (
p
< 0.05), to a doubling in percentage of good and top-quality day 3 embryos per COC, and to an increased number of vitrified day 3 embryos (
p
< 0.001), compared to STD IVM. Oocytes from follicles < 6 mm benefited most from CAPA-IVM, showing a significant increase in the amount of good and top-quality embryos compared to STD IVM. CAPA-IVM yielded significantly (
p
< 0.0001) less GV-arrested oocytes and larger oocyte diameters (
p
< 0.05) than STD IVM.
Conclusions
CAPA-IVM brings significant improvements in maturation and embryological outcomes, most notably to oocytes from small antral follicles (< 6 mm), which can be easily retrieved from patients with a minimal ovarian stimulation. The study demonstrates the robustness and transferability of the CAPA-IVM method across laboratories and populations.
The influence of Macrotermes falciger activity on clays, sesquioxides and water-dispersible clay (WDC) content was investigated by a physico-chemical, mineralogical and micromorphological study of ...termite mound and control soil profiles at various sites near Lubumbashi, SE Katanga, D.R. Congo. X-ray diffraction reveals that the termite-mound materials are enriched in 2:1 clays, especially mica and expandable clay minerals, and selective dissolution analyses show that they contain greater relative amounts of Mn oxides and poorly crystalline Fe oxides, relative to the surrounding Ferralsols. The water-dispersible clay (WDC) content is much higher (4–87 fold) in epigeal mound parts than in the control soils. Enrichment in 2:1 clays of the mounds is attributed to upward transport of mica and smectite as part of soil aggregates or saprolite materials used in mound construction. The difference in nature and abundance of sesquioxides between termite mound and control soil is related to a difference in moisture regime, whereby the basal part of the mounds are characterized by conditions with alternating reducing/oxidizing conditions, in contrast to the surrounding well-drained ferralitic soils. The much greater degree of clay dispersibility in termite mound materials than in the surrounding soils is mainly due to differences in clay properties, primarily surface charge characteristics, and to differences in Fe oxide content and mode of occurrence. The high water-dispersible clay content of termite mound materials is confirmed by micromorphological features, including abundant clay coatings and fragments of coatings.
► Higher 2:1 clay content in Macrotermes mounds than in control soils ► Macrotermes mounds are enriched in Mn oxides and poorly crystalline Fe oxides. ► Higher WDC content in Macrotermes mounds than in control soils ► Micromorphological evidence for clay translocation in Macrotermes mounds ► Evidence of periodic changes in redox conditions within Macrotermes mounds
Influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus are the most common viruses associated with acute lower respiratory infections in young children (<5 years) and ...older people (≥65 years). A global report of the monthly activity of these viruses is needed to inform public health strategies and programmes for their control.
In this systematic analysis, we compiled data from a systematic literature review of studies published between Jan 1, 2000, and Dec 31, 2017; online datasets; and unpublished research data. Studies were eligible for inclusion if they reported laboratory-confirmed incidence data of human infection of influenza virus, respiratory syncytial virus, parainfluenza virus, or metapneumovirus, or a combination of these, for at least 12 consecutive months (or 52 weeks equivalent); stable testing practice throughout all years reported; virus results among residents in well-defined geographical locations; and aggregated virus results at least on a monthly basis. Data were extracted through a three-stage process, from which we calculated monthly annual average percentage (AAP) as the relative strength of virus activity. We defined duration of epidemics as the minimum number of months to account for 75% of annual positive samples, with each component month defined as an epidemic month. Furthermore, we modelled monthly AAP of influenza virus and respiratory syncytial virus using site-specific temperature and relative humidity for the prediction of local average epidemic months. We also predicted global epidemic months of influenza virus and respiratory syncytial virus on a 5° by 5° grid. The systematic review in this study is registered with PROSPERO, number CRD42018091628.
We initally identified 37 335 eligible studies. Of 21 065 studies remaining after exclusion of duplicates, 1081 full-text articles were assessed for eligibility, of which 185 were identified as eligible. We included 246 sites for influenza virus, 183 sites for respiratory syncytial virus, 83 sites for parainfluenza virus, and 65 sites for metapneumovirus. Influenza virus had clear seasonal epidemics in winter months in most temperate sites but timing of epidemics was more variable and less seasonal with decreasing distance from the equator. Unlike influenza virus, respiratory syncytial virus had clear seasonal epidemics in both temperate and tropical regions, starting in late summer months in the tropics of each hemisphere, reaching most temperate sites in winter months. In most temperate sites, influenza virus epidemics occurred later than respiratory syncytial virus (by 0·3 months 95% CI −0·3 to 0·9) while no clear temporal order was observed in the tropics. Parainfluenza virus epidemics were found mostly in spring and early summer months in each hemisphere. Metapneumovirus epidemics occurred in late winter and spring in most temperate sites but the timing of epidemics was more diverse in the tropics. Influenza virus epidemics had shorter duration (3·8 months 3·6 to 4·0) in temperate sites and longer duration (5·2 months 4·9 to 5·5) in the tropics. Duration of epidemics was similar across all sites for respiratory syncytial virus (4·6 months 4·3 to 4·8), as it was for metapneumovirus (4·8 months 4·4 to 5·1). By comparison, parainfluenza virus had longer duration of epidemics (6·3 months 6·0 to 6·7). Our model had good predictability in the average epidemic months of influenza virus in temperate regions and respiratory syncytial virus in both temperate and tropical regions. Through leave-one-out cross validation, the overall prediction error in the onset of epidemics was within 1 month (influenza virus −0·2 months −0·6 to 0·1; respiratory syncytial virus 0·1 months −0·2 to 0·4).
This study is the first to provide global representations of month-by-month activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus. Our model is helpful in predicting the local onset month of influenza virus and respiratory syncytial virus epidemics. The seasonality information has important implications for health services planning, the timing of respiratory syncytial virus passive prophylaxis, and the strategy of influenza virus and future respiratory syncytial virus vaccination.
European Union Innovative Medicines Initiative Respiratory Syncytial Virus Consortium in Europe (RESCEU).
Does imprinted DNA methylation or imprinted gene expression differ between human blastocysts from conventional ovarian stimulation (COS) and an optimized two-step IVM method (CAPA-IVM) in age-matched ...polycystic ovary syndrome (PCOS) patients?
No significant differences in imprinted DNA methylation and gene expression were detected between COS and CAPA-IVM blastocysts.
Animal models have revealed alterations in DNA methylation maintenance at imprinted germline differentially methylated regions (gDMRs) after use of ARTs. This effect increases as more ART interventions are applied to oocytes or embryos. IVM is a minimal-stimulation ART with reduced hormone-related side effects and risks for patients. CAPA-IVM is an improved IVM system that includes a pre-maturation step (CAPA), followed by an IVM step, both in the presence of physiological compounds that promote oocyte developmental capacity.
For DNA methylation analysis 20 CAPA-IVM blastocysts were compared to 12 COS blastocysts. For RNA-Seq analysis a separate set of 15 CAPA-IVM blastocysts were compared to 5 COS blastocysts.
COS embryos originated from 12 patients with PCOS (according to Rotterdam criteria) who underwent conventional ovarian stimulation. For CAPA-IVM 23 women were treated for 3-5 days with highly purified hMG (HP-hMG) and no hCG trigger was given before oocyte retrieval. Oocytes were first cultured in pre-maturation medium (CAPA for 24 h containing C-type natriuretic peptide), followed by an IVM step (30 h) in medium containing FSH and Amphiregulin. After ICSI, Day 5 or 6 embryos in both groups were vitrified and used for post-bisulphite adaptor tagging (PBAT) DNA methylation analysis or RNA-seq gene expression analysis of individual embryos. Data from specific genes and gDMRs were extracted from the PABT and RNA-seq datasets.
CAPA-IVM blastocysts showed similar rates of methylation and gene expression at gDMRs compared to COS embryos. In addition, expression of major epigenetic regulators was similar between the groups.
The embryos from the COS group were generated in a range of culture media. The CAPA-IVM embryos were all generated using the same sperm donor. The DNA methylation level of gDMRs in purely in vivo-derived human blastocysts is not known.
A follow-up of children born after CAPA-IVM is important as it is for other new ARTs, which are generally introduced into clinical practice without prior epigenetic safety studies on human blastocysts. CAPA-IVM opens new perspectives for patient-friendly ART in PCOS.
IVM research at the Vrije Universiteit Brussel has been supported by grants from the Institute for the Promotion of Innovation by Science and Technology in Flanders (Agentschap voor Innovatie door Wetenschap en Technologie-IWT, project 110680), the Fund for Research Flanders (Fonds voor Wetenschappelijk Onderzoek-Vlaanderen-FWO-AL 679 project, project G.0343.13), the Belgian Foundation Against Cancer (HOPE project, Dossier C69Ref Nr 2016-119) and the Vrije Universiteit Brussel (IOF Project 4R-ART Nr 2042). Work in G.K.'s laboratory is supported by the UK Biotechnology and Biological Sciences Research Council and Medical Research Council. The authors have no conflicts of interest.
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