scholarly journals Dynamic Assay for Profiling Anti-SARS-CoV-2 Antibodies and Their ACE2/Spike RBD Neutralization Capacity

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1371
Author(s):  
Thomas Phelan ◽  
Jean Dunne ◽  
Niall Conlon ◽  
Clíona Ní Cheallaigh ◽  
W. Mark Abbott ◽  
...  
Keyword(s):  
New York ◽  
Neutralization Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Infection Model ◽  
Neutralization Capacity ◽  
School Of Medicine ◽  
Antibody Isotypes ◽  
Dynamic Assay ◽  
A Minor

Serological assays have been widely employed during the coronavirus disease 2019 (COVID-19) pandemic to measure antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and to track seroconversion in populations. However, currently available assays do not allow determination of neutralization capacity within the assay protocol. Furthermore, commercial serology assays have a high buy-in cost that is inaccessible for many research groups. We have replicated the serological enzyme-linked immunosorbent assay for the detection of SARS-CoV-2 antibody isotypes, developed at the Icahn School of Medicine at Mount Sinai, New York. Additionally, we have modified the protocol to include a neutralization assay with only a minor modification to this protocol. We used this assay to screen local COVID-19 patient sera (n = 91) and pre-COVID-19 control sera (n = 103), and obtained approximate parity with approved commercial anti-nucleoprotein-based assays with these sera. Furthermore, data from our neutralization assay closely aligns with that generated using a spike-based pseudovirus infection model when a subset of patient sera was analyzed.

An Enzyme Linked Immunosorbent Assay for Determination of Tissue Plasminogen Activator Applied to Patients with Thromboembolic Disease

1983 ◽  
Vol 50 (03) ◽  
pp. 740-744 ◽  
Author(s):  
Nils Bergsdorf ◽  
Torbjörn Nilsson ◽  
Per Wallén
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Specific Activity ◽  
Thromboembolic Disease ◽  
Tissue Type ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type Plasminogen Activator ◽  
Tissue Plasminogen ◽  
Normal Human

SummaryUtilizing the immunoglobulin fraction from a goat antiserum against human uterine tissue plasminogen activator, an enzyme- linked immunoassay for tissue-type plasminogen activator in human plasma has been developed. With the new method, the concentration of t-PA in normal human acidified plasma is found to be 4.0 ± 1.8 (SD) ng/ml. It increases to 12 ng/ml after a tomiquet test, and to 14 ng/ml after strenous physical exercise. In a group of patients with idiopathic thromboembolic disease, the resting t-PA concentration was 5 ng/ml and the post-occlusion value 16 ng/ml. Furthermore, the patients also exhibited a normal post-occlusion rise in the concentration of plasmin-α2-antiplasmin complex. However, in 37% of the post-occlusion patient plasmas, virtually no increase in t-PA could be detected by a specific activity assay. The results indicate that the reason for a defective post-occlusion fibrinolytic activity in a majority of cases may be the presence of increased concentrations of a fast-acting specific t-PA inhibitor.

Roundtable Discussion of the Impact of the 4th World Symposium on Pulmonary Hypertension

2009 ◽  
Vol 8 (2) ◽  
pp. 89-94
Author(s):  
Robyn J. Barst ◽  
Marc Humbert ◽  
Ivan M. Robbins ◽  
Lewis J. Rubin ◽  
Robyn J. Park
Keyword(s):  
New York ◽  
Pulmonary Hypertension ◽  
Vascular Diseases ◽  
Assistant Professor ◽  
Associate Professor ◽  
Future Research ◽  
Columbia University ◽  
School Of Medicine ◽  
Maryland School ◽  
The Impact

A discussion among attendees of the 4th World Symposium on Pulmonary Hypertension took place to share “an insider's look” into the current and future research and treatment implications in pulmonary hypertension. Myung H. Park, MD, guest editor of this issue of Advances in Pulmonary Hypertension, Assistant Professor of Medicine and Director, Pulmonary Vascular Diseases Program, Division of Cardiology, University of Maryland School of Medicine, Baltimore, moderated the discussion. Participants included Robyn Barst, MD, Professor Emerita, Columbia University, New York; Marc Humbert, MD, PhD, Universite Paris-Sud, French Referal Center for Pulmonary Hypertension, Hopital Antoine-Beclere, Assistance Publique Hopitaux de Paris, Clamart, France; Ivan Robbins, MD, Associate Professor of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee; and Lewis J. Rubin, MD, Clinical Professor, Department of Medicine, University of California, San Diego.

The 32-Item Multilingual Naming Test: Cultural and Linguistic Biases in Monolingual Chinese-Speaking Older Adults

2021 ◽  
pp. 1-9
Author(s):  
Clara Li ◽  
Xiaoyi Zeng ◽  
Judith Neugroschl ◽  
Amy Aloysi ◽  
Carolyn W. Zhu ◽  
...  
Keyword(s):  
Older Adults ◽  
New York ◽  
Test Performance ◽  
Item Difficulty ◽  
Chinese Older Adults ◽  
Chinese Speakers ◽  
School Of Medicine ◽  
Consensus Conferences ◽  
Linguistic Groups ◽  
Naming Test

ABSTRACT Objectives: This study describes the performance of the Multilingual Naming Test (MINT) by Chinese American older adults who are monolingual Chinese speakers. An attempt was also made to identify items that could introduce bias and warrant attention in future investigation. Methods: The MINT was administered to 67 monolingual Chinese older adults as part of the standard dementia evaluation at the Alzheimer’s Disease Research Center (ADRC) at the Icahn School of Medicine at Mount Sinai (ISMMS), New York, USA. A diagnosis of normal cognition (n = 38), mild cognitive impairment (n = 12), and dementia (n = 17) was assigned to all participants at clinical consensus conferences using criterion sheets developed at the ADRC at ISMMS. Results: MINT scores were negatively correlated with age and positively correlated with education, showing sensitivity to demographic factors. One item, butterfly, showed no variations in responses across diagnostic groups. Inclusion of responses from different regions of China changed the answers from “incorrect” to “correct” on 20 items. The last five items, porthole, anvil, mortar, pestle, and axle, yielded a high nonresponse rate, with more than 70% of participants responding with “I don’t know.” Four items, funnel, witch, seesaw, and wig, were not ordered with respect to item difficulty in the Chinese language. Two items, gauge and witch, were identified as culturally biased for the monolingual group. Conclusions: Our study highlights the cultural and linguistic differences that might influence the test performance. Future studies are needed to revise the MINT using more universally recognized items of similar word frequency across different cultural and linguistic groups.

scholarly journals Pitfalls in the Immunochemical Determination of β‑Lactam Antibiotics in Water

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 298
Author(s):  
Alexander Ecke ◽  
Rudolf J. Schneider
Keyword(s):  
Limit Of Detection ◽  
Cost Effective ◽  
Enzyme Linked Immunosorbent Assay ◽  
Degree Of Hydrolysis ◽  
Site Analysis ◽  
Antibody Recognition ◽  
Immunochemical Determination ◽  
Key Factor ◽  
Lactam Ring

Contamination of waters with pharmaceuticals is an alarming problem as it may support the evolution of antimicrobial resistance. Therefore, fast and cost-effective analytical methods for potential on-site analysis are desired in order to control the water quality and assure the safety of its use as a source of drinking water. Antibody-based methods, such as the enzyme-linked immunosorbent assay (ELISA), can be helpful in this regard but can also have certain pitfalls in store, depending on the analyte. As shown here for the class of β-lactam antibiotics, hydrolysis of the β‑lactam ring is a key factor in the immunochemical analysis as it influences antibody recognition. With the antibody used in this study, the limit of detection (LOD) in the immunoassay could be significantly reduced by hydrolysis for the five tested penicillins, with the lowest LOD for carbenicillin (0.2 nmol/L) and the greatest impact on penicillins G and V (reduction by 85%). In addition to enhanced quantification, our strategy also provides access to information about the degree of hydrolysis in water samples as shown for the most abundant penicillin amoxicillin.

SENSITIVE AND SPECIFIC ENZYME-LINKED IMMUNOSORBENT ASSAY FOR UROKINASE-TYPE PLASMINOGEN ACTIVATOR IN HUMAN PLASMA

1987 ◽  
Author(s):  
J Grøndahl-HANSEN ◽  
N Agerlin ◽  
L S Nielsen ◽  
K Danø
Keyword(s):  
Plasminogen Activator ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mean Values ◽  
Amino Terminal ◽  
Type Plasminogen Activator ◽  
Healthy Donors ◽  
Urokinase Type Plasminogen Activator ◽  
The Mean

An enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of human urokinase-type plasminogen activator (u-PA) in plasma and serum. Microtiter plates were coated with a monoclonal antibody and incubated with standard or sample. Bound u-PA was quantitated with polyclonal antibodies conjugated with biotin, followed by avidin-peroxidase. The assay was 10-fold as sensitive as other previously reported ELISAs, the detection limit being approximately 1 pg of u-PA in a volume of 100 μl with a linear dose-response up to 15 pg of u-PA. The assay detected active u-PA and its inactive proenzyme form equally well and the recovery of both forms was higher than 90% in plasma. A variety of structurally related proteins, including t-PA, were tested, but no reaction with proteins other than u-PA and its amino-terminal degradation product were observed. The intra-assay and inter-assay coefficients of variation for determination of u-PA in plasma were 7.6% and 8.4%, respectively. The assay was equally applicable to serum. The values obtained with plasma and serum were similar, and the results were not affected by small variations in the preparation of the samples. The ELISA was used to measure the concentration of u-PA in plasma from 34 healthy donors. The mean values for u-PA in plasma from healthy donors was 1.1 ng/ml ± 0.3 ng/ml (SD) (range 0.6 - 1.5 ng/ml). No significant differences were found between men and women and no correlation between u-PA concentration and age could be demonstrated.The mean u-PA concentration in plasma from healthy donors obtained in this study is substantially lower than that reported by others. This might be due to different methods of determination of the protein content of the standard preparations or to differences in the specificity of the assays.

scholarly journals Use of a Toxin Neutralization Assay To Characterize the Serologic Response to Adenylate Cyclase Toxin after Infection with Bordetella pertussis

2016 ◽  
Vol 24 (1) ◽  
Author(s):  
Joshua C. Eby ◽  
Mary C. Gray ◽  
Jason M. Warfel ◽  
Tod J. Merkel ◽  
Erik L. Hewlett
Keyword(s):  
Adenylate Cyclase ◽  
Bordetella Pertussis ◽  
Neutralization Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunologic Response ◽  
Serum Samples ◽  
Content Type ◽  
Adenylate Cyclase Toxin ◽  
Strong Candidate ◽  
Candidate Antigen

ABSTRACT Adenylate cyclase toxin (ACT) is an essential virulence factor of Bordetella pertussis, and antibodies to ACT protect against B. pertussis infection in mice. The toxin is therefore a strong candidate antigen for addition to future acellular pertussis vaccines. In order to characterize the functionality of the immunologic response to ACT after infection, we developed an assay for testing the ability of serum samples from subjects infected with B. pertussis to neutralize ACT-induced cytotoxicity in J774 macrophage cells. Baboons develop neutralizing anti-ACT antibodies following infection with B. pertussis, and all sera from baboons with positive anti-ACT IgG enzyme-linked immunosorbent assay (ELISA) results neutralized ACT cytotoxicity. The toxin neutralization assay (TNA) was positive in some baboon sera in which ELISA remained negative. Of serum samples obtained from humans diagnosed with pertussis by PCR, anti-ACT IgG ELISA was positive in 72%, and TNA was positive in 83%. All samples positive for anti-ACT IgG ELISA were positive by TNA, and none of the samples from humans without pertussis neutralized toxin activity. These findings indicate that antibodies to ACT generated following infection with B. pertussis consistently neutralize toxin-induced cytotoxicity and that TNA can be used to improve understanding of the immunologic response to ACT after infection or vaccination.

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