scholarly journals Quantitative serology for SARS-CoV-2 using self-collected saliva and finger-stick blood

2021 ◽  
Author(s):  
Christopher Campbell ◽  
Nikhil Padmanabhan ◽  
Daniel Romero ◽  
Jessica Joe ◽  
Mikias Gebremeskel ◽  
...  
Keyword(s):  
Large Scale ◽  
Robust Methods ◽  
Quantitative Measurements ◽  
Specimen Collection ◽  
Saliva Collection ◽  
Finger Stick ◽  
Humoral Responses ◽  
Antibody Levels ◽  
Matched Samples ◽  
Serology Testing

Abstract Convenient and widespread serology testing may alter the trajectory of the COVID-19 pandemic. This study seeks to leverage high-throughput, multiplexed serologic assays, which have been adopted as benchmarks for vaccine efficacy, to support large-scale surveys of SARS-CoV-2 immunity using finger-stick blood and/or saliva. Specifically, we optimized MSD’s serology assays, which were analytically validated for serum, to test self-collected finger-stick blood and saliva samples. We show that these assays can be used with FDA-registered specimen collection devices to obtain quantitative measurements for self-collected samples. Antibody levels were measured using an electrochemiluminescent (ECL) multiplex immunoassay, which has been used to measure humoral responses to several COVID-19 vaccines, including those funded by the U.S. Government’s Operation Warp Speed. First, we show that salivary antibodies are stable without refrigeration or preservatives for at least five days. Using matched samples, we show that testing of saliva and finger-stick blood equivalently identified individuals with humoral responses to CoV-2 antigens. Moreover, we piloted a simple saliva collection kit that can be used to safely send samples through the mail. This work demonstrates that robust methods for self-collection of finger-stick blood and saliva, in combination with quantitative, automated immunoassays, provide the technical capabilities needed to support large-scale serology testing.

scholarly journals Regression-Based Identification of Behavior-Encoding Neurons During Large-Scale Optical Imaging of Neural Activity at Cellular Resolution

2011 ◽  
Vol 105 (2) ◽  
pp. 964-980 ◽  
Author(s):  
Andrew Miri ◽  
Kayvon Daie ◽  
Rebecca D. Burdine ◽  
Emre Aksay ◽  
David W. Tank
Keyword(s):  
Time Series ◽  
Optical Imaging ◽  
Neural Activity ◽  
Laser Scanning ◽  
Large Scale ◽  
Neural Encoding ◽  
Quantitative Measurements ◽  
Cellular Resolution ◽  
Activity Measurements ◽  
General Regression

The advent of methods for optical imaging of large-scale neural activity at cellular resolution in behaving animals presents the problem of identifying behavior-encoding cells within the resulting image time series. Rapid and precise identification of cells with particular neural encoding would facilitate targeted activity measurements and perturbations useful in characterizing the operating principles of neural circuits. Here we report a regression-based approach to semiautomatically identify neurons that is based on the correlation of fluorescence time series with quantitative measurements of behavior. The approach is illustrated with a novel preparation allowing synchronous eye tracking and two-photon laser scanning fluorescence imaging of calcium changes in populations of hindbrain neurons during spontaneous eye movement in the larval zebrafish. Putative velocity-to-position oculomotor integrator neurons were identified that showed a broad spatial distribution and diversity of encoding. Optical identification of integrator neurons was confirmed with targeted loose-patch electrical recording and laser ablation. The general regression-based approach we demonstrate should be widely applicable to calcium imaging time series in behaving animals.

scholarly journals Computational generation of an annotated gigalibrary of synthesizable, composite peptidic macrocycles

2020 ◽  
Vol 117 (40) ◽  
pp. 24679-24690
Author(s):  
Ishika Saha ◽  
Eric K. Dang ◽  
Dennis Svatunek ◽  
Kendall N. Houk ◽  
Patrick G. Harran
Keyword(s):  
Virtual Screening ◽  
Open Source ◽  
Open Source Software ◽  
Large Scale ◽  
Three Dimensional ◽  
Pharmacological Properties ◽  
Robust Methods ◽  
Small Peptide ◽  
Multistep Reaction ◽  
Condensed Heterocycles

Peptidomimetic macrocycles have the potential to regulate challenging therapeutic targets. Structures of this type having precise shapes and drug-like character are particularly coveted, but are relatively difficult to synthesize. Our laboratory has developed robust methods that integrate small-peptide units into designed scaffolds. These methods create macrocycles and embed condensed heterocycles to diversify outcomes and improve pharmacological properties. The hypothetical scope of the methodology is vast and far outpaces the capacity of our experimental format. We now describe a computational rendering of our methodology that creates an in silico three-dimensional library of composite peptidic macrocycles. Our open-source platform, CPMG (Composite Peptide Macrocycle Generator), has algorithmically generated a library of 2,020,794,198 macrocycles that can result from the multistep reaction sequences we have developed. Structures are generated based on predicted site reactivity and filtered on the basis of physical and three-dimensional properties to identify maximally diverse compounds for prioritization. For conformational analyses, we also introduce ConfBuster++, an RDKit port of the open-source software ConfBuster, which allows facile integration with CPMG and ready parallelization for better scalability. Our approach deeply probes ligand space accessible via our synthetic methodology and provides a resource for large-scale virtual screening.

Antibodies against somatic antigens and excreted/secreted products of Brugia pahangi in rats with patent and non-patent infections

Parasitology ◽  
1992 ◽  
Vol 105 (3) ◽  
pp. 425-434 ◽  
Author(s):  
C. Fletcher ◽  
C. C. Wu
Keyword(s):  
Subsequent Development ◽  
Consistent Difference ◽  
Sprague Dawley ◽  
Igg Antibody ◽  
Western Blots ◽  
Brugia Pahangi ◽  
Sprague Dawley Rats ◽  
Humoral Responses ◽  
Antibody Levels ◽  
Somatic Antigens

SUMMARYThe humoral responses of Sprague–Dawley rats infected with Brugia pahangi were examined for up to 6 months after infection by ELISA, immunoblotting, and IFAT. In 2 experiments, 50% and 62·5% of rats developed patent, microfilaraemic infections. Mean adult worm burdens at autopsy were approximately 2% of the inoculum, and only patent rats yielded living adult worms. IgG antibody levels against crude somatic extracts (CSE) of all parasite stages and against adult excreted/secreted (ES) products were significantly higher in patent than non-patent rats. Both patent and non-patent rats produced anti-microfilarial surface antibody, as revealed by immunofluorescence. Immunostaining of Western blots by early infection sera showed no consistent difference in recognition of infective larval (L3) antigenic components by IgG or IgM antibody between eventually-patent and eventually-non-patent rats. By 26 weeks, however, patent rats recognized more components. The data suggest that antibodies against L3, adult, and microfilarial somatic antigens, ES antigens and microfilarial surface antigens do not correlate with the subsequent development of microfilaraemia in any individual rat.

scholarly journals Evaluation of Two Types of Sponges Used To Collect Cervical Secretions and Assessment of Antibody Extraction Protocols for Recovery of Neutralizing Anti-Human Papillomavirus Type 16 Antibodies

2007 ◽  
Vol 15 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Troy J. Kemp ◽  
Allan Hildesheim ◽  
Roni T. Falk ◽  
John T. Schiller ◽  
Douglas R. Lowy ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Neutralization Assay ◽  
Serum Samples ◽  
Neutralizing Activity ◽  
Human Papillomavirus Type 16 ◽  
Vaccine Trials ◽  
Specimen Collection ◽  
Virus Like Particle ◽  
Protection Against Infection ◽  
Antibody Levels

ABSTRACT Immunogenicity evaluations in human papillomavirus (HPV) vaccine trials have relied on serological samples, yet cervical antibodies are likely to be most relevant for protection against infection. In order to assess functional antibody levels at the cervix, the secreted-alkaline-phosphatase neutralization assay (SEAPNA) was used to measure HPV-neutralizing activity. We assessed the variability of the SEAPNA with serum samples after vaccination with an HPV type 16 (HPV16) L1 virus-like particle vaccine and whether the SEAPNA can be used to monitor neutralizing activity at the cervix. The SEAPNA has an overall coefficient of variation of 29.3%. Recovery from ophthalmic sponges was assessed by spiking V5 (mouse anti-HPV16) antibody onto and extracting it from sterile Merocel and Ultracell sponges and sponges used to collect specimens from participants. V5 recovery from sterile Merocel sponges was complete, yet that from Ultracell sponges was null. The mean V5 recoveries from participant Ultracell and Merocel sponges were 61.2% and 93.5%, respectively, suggesting that Merocel sponges are more appropriate for specimen collection. The SEAPNA can be applied to determine the surrogates of protection and to examine the durability of protection at the cervix.

scholarly journals Detection, prevalence, and duration of humoral responses to SARS-CoV-2 under conditions of limited population exposure.

2020 ◽  
Author(s):  
Tyler J Ripperger ◽  
Jennifer L Uhrlaub ◽  
Makiko Watanabe ◽  
Rachel Wong ◽  
Yvonne Castaneda ◽  
...  
Keyword(s):  
Local Community ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Population Level ◽  
Population Exposure ◽  
Antibody Titers ◽  
Asymptomatic Individuals ◽  
Humoral Responses ◽  
Antibody Levels ◽  
Antibody Kinetics

We conducted an extensive serological study to quantify population-level exposure and define correlates of immunity against SARS-CoV-2. We found that relative to mild COVID-19 cases, individuals with severe disease exhibited elevated authentic virus-neutralizing titers and antibody levels against nucleocapsid (N) and the receptor binding domain (RBD) and the S2 region of spike protein. Unlike disease severity, age and sex played lesser roles in serological responses. All cases, including asymptomatic individuals, seroconverted by 2 weeks post-PCR confirmation. RBD- and S2-specific and neutralizing antibody titers remained elevated and stable for at least 2-3 months post-onset, whereas those against N were more variable with rapid declines in many samples. Testing of 5882 self-recruited members of the local community demonstrated that 1.24% of individuals showed antibody reactivity to RBD. However, 18% (13/73) of these putative seropositive samples failed to neutralize authentic SARS-CoV-2 virus. Each of the neutralizing, but only 1 of the non-neutralizing samples, also displayed potent reactivity to S2. Thus, inclusion of multiple independent assays markedly improved the accuracy of antibody tests in low seroprevalence communities and revealed differences in antibody kinetics depending on the viral antigen. In contrast to other reports, we conclude that immunity is durable for at least several months after SARS-CoV-2 infection.

scholarly journals Suitability and Sufficiency of Telehealth Clinician-Observed, Participant-Collected Samples for SARS-CoV-2 Testing: The iCollect Cohort Pilot Study

10.2196/19731 ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. e19731 ◽  
Author(s):  
Jodie L Guest ◽  
Patrick S Sullivan ◽  
Mariah Valentine-Graves ◽  
Rachel Valencia ◽  
Elizabeth Adam ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Rnase P ◽  
Ribonuclease P ◽  
Laboratory Assessment ◽  
Testing Strategies ◽  
Specimen Collection ◽  
Oropharyngeal Swab ◽  
Polymerase Chain ◽  
Respiratory Coronavirus ◽  
Serology Testing

Background The severe acute respiratory coronavirus 2 (SARS-CoV-2) pandemic calls for expanded opportunities for testing, including novel testing strategies such as home-collected specimens. Objective We aimed to understand whether oropharyngeal swab (OPS), saliva, and dried blood spot (DBS) specimens collected by participants at home and mailed to a laboratory were sufficient for use in diagnostic and serology tests of SARS-CoV-2. Methods Eligible participants consented online and were mailed a participant-collection kit to support collection of three specimens for SARS-CoV-2 testing: saliva, OPS, and DBS. Participants performed the specimen collection procedures during a telehealth video appointment while clinical observers watched and documented the suitability of the collection. The biological sufficiency of the specimens for detection of SARS-CoV-2 by reverse transcriptase–polymerase chain reaction and serology testing was assessed by laboratorians using visual inspection and quantification of the nucleic acid contents of the samples by ribonuclease P (RNase P) measurements. Results Of the enrolled participants,153/159 (96.2%) returned their kits, which were included in this analysis. All these participants attended their video appointments. Clinical observers assessed that of the samples collected, 147/153 (96.1%) of the saliva samples, 146/151 (96.7%) of the oropharyngeal samples, and 135/145 (93.1%) of the DBS samples were of sufficient quality for submission for laboratory testing; 100% of the OPS samples and 98% of the saliva samples had cycle threshold values for RNase P <30, indicating that the samples contained sufficient nucleic acid for RNA-PCR testing for SARS-CoV-2. Conclusions These pilot data indicate that most participant-collected OPS, saliva, and DBS specimens are suitable and sufficient for testing for SARS-CoV-2 RNA and serology. Clinical observers rated the collection of specimens as suitable for testing, and visual and quantitative laboratory assessment indicated that the specimens were biologically sufficient. These data support the utility of participant-collected and mailed-in specimens for SARS-CoV-2 testing. International Registered Report Identifier (IRRID) RR2-10.2196/19054

scholarly journals Survey of the terrestrial habitats and vegetation of Shetland, 1974 – a framework for long-term ecological monitoring

2016 ◽  
Vol 8 (1) ◽  
pp. 89-103 ◽  
Author(s):  
Claire M. Wood ◽  
Robert G. H. Bunce
Keyword(s):  
Natural Environment ◽  
Large Scale ◽  
Oil Industry ◽  
Ecological Monitoring ◽  
Robust Methods ◽  
Ecological Changes ◽  
Terrestrial Habitats ◽  
Environmental Monitoring Programme

Abstract. A survey of the natural environment was undertaken in Shetland in 1974, after concern was expressed that large-scale development from the new oil industry could threaten the natural features of the islands. A framework was constructed by the Institute of Terrestrial Ecology on which to select samples for the survey. The vegetation and habitat data that were collected, along with the sampling framework, have recently been made public via the following doi:10.5285/06fc0b8c-cc4a-4ea8-b4be-f8bd7ee25342 (Terrestrial habitat, vegetation and soil data from Shetland, 1974) and doi:10.5285/f1b3179e-b446-473d-a5fb-4166668da146 (Land Classification of Shetland 1974). In addition to providing valuable information about the state of the natural environment of Shetland, the repeatable and statistically robust methods developed in the survey were used to underpin the Countryside Survey, Great Britain's national long-term integrated environmental monitoring programme. The demonstration of the effectiveness of the methodology indicates that a repeat of the Shetland survey would yield statistics about ecological changes in the islands, such as those arising from the impacts of the oil industry, a range of socio-economic impacts, and perhaps climate change. Currently no such figures are available, although there is much information on the sociological impacts, as well as changes in agriculture.

scholarly journals Sensitive detection of SARS-CoV-2-specific-antibodies in dried blood spot samples

2020 ◽  
Author(s):  
Gabriella L. Morley ◽  
Stephen Taylor ◽  
Sian Jossi ◽  
Marisol Perez-Toledo ◽  
Sian E. Faustini ◽  
...  
Keyword(s):  
Sampling Method ◽  
Dried Blood Spot ◽  
Serological Testing ◽  
Spike Glycoprotein ◽  
Serum Samples ◽  
Perfect Agreement ◽  
Specific Antibodies ◽  
Antibody Levels ◽  
Matched Samples ◽  
Blood Spot

AbstractImportancePopulation-wide serological testing is an essential component in understanding the COVID-19 pandemic. The logistical challenges of undertaking widespread serological testing could be eased through use of a reliable dried blood spot (DBS) sampling method.ObjectiveTo validate the use of dried blood spot sampling for the detection of SARS-CoV-2-specific antibodies.Design, setting and participantsEighty-seven matched DBS and serum samples were obtained from eighty individuals, including thirty-one who were previously PCR-positive for SARS-CoV-2. DBS eluates and sera were used in an ELISA to detect antibodies to the viral spike protein.ResultsSpecific anti-SARS-Cov-2 spike glycoprotein antibodies were detectable in both serum and DBS eluate and there was a significant correlation between the antibody levels detected in matched samples (r = 0.96, p<0.0001). Using serum as the gold standard in the assay, matched DBS samples achieved a Cohen’s kappa coefficient of 0.975 (near-perfect agreement), a sensitivity of 98.1% and specificity of 100%, for detecting anti-spike glycoprotein antibodies.Conclusions and relevanceEluates from DBS samples are a reliable and reproducible source of antibodies to be used for the detection of SARS-CoV-2-specific antibodies. The use of DBS sampling could complement the use of venepuncture in the immunosurveillance of COVID-19 in both low and high income settings.

scholarly journals Serology characteristics of SARS-CoV-2 infection after exposure and post-symptom onset

2020 ◽  
Vol 56 (2) ◽  
pp. 2000763 ◽  
Author(s):  
Bin Lou ◽  
Ting-Dong Li ◽  
Shu-Fa Zheng ◽  
Ying-Ying Su ◽  
Zhi-Yong Li ◽  
...  
Keyword(s):  
Early Stage ◽  
Antibody Test ◽  
Igg Antibodies ◽  
Specific Diagnosis ◽  
Treatment And Prevention ◽  
Significant Difference ◽  
Antibody Levels ◽  
Antibody Dynamics ◽  
Serology Testing ◽  
Post Onset

BackgroundTimely diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a prerequisite for treatment and prevention. The serology characteristics and complement diagnosis value of the antibody test to RNA test need to be demonstrated.MethodSerial sera of 80 patients with PCR-confirmed coronavirus disease 2019 (COVID-19) were collected at the First Affiliated Hospital of Zhejiang University, Hangzhou, China. Total antibody (Ab), IgM and IgG antibodies against SARS-CoV-2 were detected, and the antibody dynamics during the infection were described.ResultsThe seroconversion rates for Ab, IgM and IgG were 98.8%, 93.8% and 93.8%, respectively. The first detectible serology marker was Ab, followed by IgM and IgG, with a median seroconversion time of 15, 18 and 20 days post exposure (d.p.e.) or 9, 10 and 12 days post onset (d.p.o.), respectively. The antibody levels increased rapidly beginning at 6 d.p.o. and were accompanied by a decline in viral load. For patients in the early stage of illness (0–7 d.p.o), Ab showed the highest sensitivity (64.1%) compared with IgM and IgG (33.3% for both; p<0.001). The sensitivities of Ab, IgM and IgG increased to 100%, 96.7% and 93.3%, respectively, 2 weeks later. When the same antibody type was detected, no significant difference was observed between enzyme-linked immunosorbent assays and other forms of immunoassays.ConclusionsA typical acute antibody response is induced during SARS-CoV-2 infection. Serology testing provides an important complement to RNA testing in the later stages of illness for pathogenic-specific diagnosis and helpful information to evaluate the adapted immunity status of patients.

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