scholarly journals Development and validation of a quantitative, non-invasive, highly sensitive and specific, electrochemical assay for anti-SARS-CoV-2 IgG antibodies in saliva

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0251342
Author(s):  
Samantha H. Chiang ◽  
Michael Tu ◽  
Jordan Cheng ◽  
Fang Wei ◽  
Feng Li ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Antibody Test ◽  
Electrochemical Measurement ◽  
Population Based ◽  
Medical Attention ◽  
Plasma Samples ◽  
Polymer Gel ◽  
Igg Antibodies ◽  
Electrochemical Assay ◽  
Non Invasive

Amperial™ is a novel assay platform that uses immobilized antigen in a conducting polymer gel followed by detection via electrochemical measurement of oxidation-reduction reaction between H2O2/Tetrametylbenzidine and peroxidase enzyme in a completed assay complex. A highly specific and sensitive assay was developed to quantify levels of IgG antibodies to SARS-CoV-2 in saliva. After establishing linearity and limit of detection we established a reference range of 5 standard deviations above the mean. There were no false positives in 667 consecutive saliva samples obtained prior to 2019. Saliva was obtained from 34 patients who had recovered from documented COVID-19 or had documented positive serologies. All of the patients with symptoms severe enough to seek medical attention had positive antibody tests and 88% overall had positive results. We obtained blinded paired saliva and plasma samples from 14 individuals. The plasma was analyzed using an EUA-FDA cleared ELISA kit and the saliva was analyzed by our Amperial™ assay. All 5 samples with negative plasma titers were negative in saliva testing. Eight of the 9 positive plasma samples were positive in saliva and 1 had borderline results. A CLIA validation was performed as a laboratory developed test in a high complexity laboratory. A quantitative non-invasive saliva based SARS-CoV-2 antibody test was developed and validated with sufficient specificity to be useful for population-based monitoring and monitoring of individuals following vaccination.

scholarly journals Development and validation of a highly sensitive and specific electrochemical assay to quantify anti-SARS-CoV-2 IgG antibodies to facilitate pandemic surveillance and monitoring of vaccine response

2020 ◽  
Author(s):  
Samantha H. Chiang ◽  
Michael Tu ◽  
Jordan Cheng ◽  
Fang Wei ◽  
Feng Li ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Conductive Polymer ◽  
Antibody Test ◽  
Population Based ◽  
Medical Attention ◽  
Plasma Samples ◽  
Polymer Gel ◽  
Igg Antibodies ◽  
Vaccine Response ◽  
Electrochemical Assay

AbstractAmperial™ is a novel assay platform that uses immobilized antigen in a conductive polymer gel followed by an electrochemical detection. A highly specific and sensitive assay was developed to quantify levels of IgG antibodies to SARS-CoV-2 in saliva. After establishing linearity and limit of detection we established a reference range of 5 standard deviations above the mean. There were no false positives in 667 consecutive saliva samples obtained prior to 2019. Saliva was obtained from 34 patients who had recovered from documented COVID-19 or had documented positive serologies. All of the patients with symptoms severe enough to seek medical attention had positive antibody tests and 88% overall had positive results.We obtained blinded paired saliva and plasma samples from 14 individuals. The plasma was analyzed using an EUA-FDA cleared ELISA kit and the saliva was analyzed by our Amperial™ assay. All 5 samples with negative plasma titers were negative in saliva testing. Eight of the 9 positive plasma samples were positive in saliva and 1 had borderline results. A CLIA validation was performed as a laboratory developed test in a high complexity laboratory.A quantitative non-invasive saliva based SARSCoV-2 antibody test was developed and validated with sufficient specificity to be useful for population-based monitoring and monitoring of individuals following vaccination.

scholarly journals A New Saliva-Based Lateral-Flow SARS-CoV-2 IgG Antibody Test for mRNA Vaccination

2021 ◽  
Author(s):  
Dingying Shan ◽  
Jessica Hsiung ◽  
Kevin P. Bliden ◽  
Su Zhao ◽  
Tao Liao ◽  
...  
Keyword(s):  
Vaccine Dose ◽  
Rapid Test ◽  
High Sensitivity ◽  
Antibody Test ◽  
Lateral Flow ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Non Invasive ◽  
Antibody Persistence ◽  
Wide Range

Sensitive detection of IgG antibodies against SARS-CoV-2 is important to assessing immune responses to viral infection or vaccination and immunity duration. Antibody assays using non-invasive body fluids such as saliva could facilitate mass testing including young children, elderly and those who resist blood draws, and easily allowing longitudinal testing/monitoring of antibodies over time. Here, we developed a new lateral flow (nLF) assay that sensitively detects SARS-CoV-2 IgG antibodies in the saliva samples of vaccinated individuals and previous COVID-19 patients. The 25-minute nLF assay detected anti-spike protein (anti-S1) IgG in saliva samples with 100% specificity and high sensitivity from both vaccinated (99.51% for samples ≥ 19 days post 1st Pfizer/BioNTech or Moderna mRNA vaccine dose) and infected individuals. Antibodies against nucleocapsid protein (anti-NCP) was detected only in the saliva samples of COVID-19 patients and not in vaccinated samples, allowing facile differentiation of vaccination from infection. SARS-CoV-2 anti-S1 IgG antibody in saliva measured by nLF demonstrated similar evolution trends post vaccination to that in matching dried blood spot (DBS) samples measured by a quantitative pGOLD lab-test, enabling the nLF to be a valid tool for non-invasive personalized monitoring of SARS-CoV-2 antibody persistence. The new salivary rapid test platform can be applied for non-invasive detection of antibodies against infection and vaccination in a wide range of diseases.

scholarly journals Prevalence of nocturia among community-dwelling adults: a population-based study in Malaysia

BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hui-Yin Yow ◽  
John Jeh Lung Tiong ◽  
Chun-Wai Mai ◽  
Esther van der Werf ◽  
Zulkifli Md Zainuddin ◽  
...  
Keyword(s):  
Medical Condition ◽  
Population Based ◽  
Community Dwelling ◽  
Medical Attention ◽  
Night Time ◽  
Cross Sectional ◽  
Population Based Study ◽  
Waking Up ◽  
The Impact

Abstract Background Nocturia is widely prevalent condition with detrimental effects on quality of life and general health. In Malaysia, there is a lack of up-to-date prevalence study on nocturia. This study aimed to investigate the prevalence of nocturia and awareness pertaining to nocturia among Malaysian adults. Methods A cross-sectional population-based study was conducted among Malaysian adults aged ≥ 18 years old. The data was collected by mixed mode self-administered questionnaire from May 2019 to September 2019. Nocturia was defined as one or more voids at night. Results There were a total of 4616 respondents with 74.5% of response rate. The overall prevalence of nocturia among Malaysian adults was found to be 57.3%. In multivariate analysis, respondents aged 31–40 (1.91 [1.52–2.40]) or > 60 years old (2.03 [1.48–2.71]), and those who presented with hypertension (2.84 [2.28–3.53]), diabetes mellitus (1.78 [1.42–2.25]), renal disease (3.58 [1.93–6.63]) or overactive bladder (1.61 [1.10–2.35]) were associated with higher prevalence of nocturia. A significantly lower disease prevalence (p < 0.05) was noted among those aged 41–50 (0.73 [0.59–0.91]), male (0.78 [0.69–0.88]) and Chinese (0.47 [0.30–0.74]) or Indian (0.34 [0.21–0.54]) ethnicities. A total of 37.3% of respondents with nocturia reported that they faced sleeping difficulty about half the time or more after waking up in the middle of night. Those who had ≥ 2 voids per night experienced significantly higher mean bother score than those who had 1 void per night (p < 0.001). Approximately half (56.7%) of all respondents were not aware that night time urination is a medical condition. Only 25.2% of respondents with nocturia had sought medical attention for their nocturia. Conclusions The prevalence of nocturia among Malaysian adults is high and strongly influenced by age, sex, race and comorbidities. However, the general awareness pertaining to nocturia being a health issue remains low among Malaysians. The findings also highlighted the impact of nocturia on sleep and the need for nocturia education to better address this disease.

scholarly journals Immunochromatographic Strip Test for Rapid Detection of Nevirapine in Plasma Samples from Human Immunodeficiency Virus-Infected Patients

2007 ◽  
Vol 51 (9) ◽  
pp. 3361-3363 ◽  
Author(s):  
Tim R. Cressey ◽  
Sawitree Nangola ◽  
Yardpiroon Tawon ◽  
Mookda Pattarawarapan ◽  
Marc Lallemant ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Limit Of Detection ◽  
Drug Level ◽  
Plasma Samples ◽  
Immunochromatographic Strip ◽  
Resource Limited ◽  
Qualitative Detection ◽  
Immunodeficiency Virus ◽  
Immunochromatographic Strip Test ◽  
Strip Test

ABSTRACT We report a novel one-step immunochromatographic strip test for the rapid, qualitative detection of nevirapine in plasma samples from human immunodeficiency virus-infected patients. The sensitivity was 100% (95% confidence interval [95% CI], 97.8 to 100%), and the specificity was 99.5% (95% CI, 97.2 to 99.9%). The limit of detection was 25 ng/ml. Immunochromatographic strip tests are simple, rapid, and cheap assays that could greatly facilitate drug level monitoring in resource-limited settings.

scholarly journals Prevalence of health services usage and associated factors in the Amazon region of Brazil: a population-based cross-sectional study

BMJ Open ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. e017966 ◽  
Author(s):  
Maria Elizete A Araujo ◽  
Marcus T Silva ◽  
Tais F Galvao ◽  
Mauricio G Pereira
Keyword(s):  
Health Services ◽  
Associated Factors ◽  
Prevalence Ratio ◽  
The Elderly ◽  
Population Based ◽  
Cross Sectional Study ◽  
Metropolitan Region ◽  
Medical Attention ◽  
Cross Sectional ◽  
Physician Visits

ObjectivesTo estimate the prevalence of healthcare use and associated factors in the Manaus metropolitan region and to describe the reasons for lack of access.DesignCross-sectional population-based study.SettingA survey conducted between May and August of 2015 in eight cities from Manaus metropolitan region, Amazonas, Brazil.Participants4001 adults ≥18 years of age.Primary outcomes measuresPhysician visits, dentist visits and hospitalisations in the last 12 months were the primary outcomes. Associated factors were investigated through the calculation of prevalence ratio (PR) obtained by hierarchical Poisson regression modelling.Results4001 adults were included in the study, 53% of whom were women. The self-reported prevalence of medical visits was 77% (95% CI 75% to 77%); dentist visits, 36% (95% CI 34% to 37%) and hospital admission, 7% (95% CI 6% to 7%). Physician visits were higher in women PR=1.18 (95% CI 1.14 to 1.23), the elderly PR=1.18 (95% CI 1.10 to 1.26) and people with health insurance PR=1.14 (95% CI 1.10 to 1.19). Dentist visits declined with older age PR=0.38 (95% CI 0.30 to 0.49), lower education level PR=0.62 (95% CI 0.51 to 0.74) and lower economic class PR=0.65 (95% CI 0.57 to 0.75). Hospitalisations were found to be twice as frequent for women than for men and three times as frequent among those who reported very poor health status. Among the individuals who did not receive medical attention in the previous 2 weeks, 58% reported lack of facilities or appointment unavailable and 14% reported lack of doctors.ConclusionWhile more than half visited the doctor in the last year, a lower proportion of people with socioeconomic inequities visited the dentist. Organisational and service policies are needed to increase equity in health services in the region.

Circulating miR-126 as a Potential Non-invasive Biomarker for Intracranial Aneurysmal Rupture: A Pilot Study

2021 ◽  
Vol 19 ◽  
Author(s):  
Jianing Wu ◽  
Ilgiz Gareev ◽  
Ozal Beylerli ◽  
Albert Mukhamedzyanov ◽  
Valentin Pavlov ◽  
...  
Keyword(s):  
Aneurysmal Subarachnoid Hemorrhage ◽  
Diagnostic Value ◽  
Plasma Samples ◽  
Expression Levels ◽  
Time Points ◽  
Non Invasive ◽  
Risk Of Rupture ◽  
Life Threatening ◽  
Healthy Control ◽  
New Biomarkers

Aim: Intracranial aneurysms (IAs) are characterized by abnormal dilation and thinning of the cerebral vessels wall, leading to rupture and life-threatening aneurysmal subarachnoid hemorrhage (aSAH) condition. This dictates the need to find new biomarkers that predict the presence of IAs and the risk of their rupture. The aim of this study was to measure circulating miR-126 at various time points post-aSAH to identify the timing of peak levels. Methods: Plasma samples from 62 patients with unruptured IAs (UIAs), 80 patients with aSAH at various time points (1, 3, 7, and 14 days post-event), and 47 healthy control were collected and subjected to qRT-PCR analyses for the expression levels of circulating miR-126. ROC curve and AUC were used to evaluate the diagnostic value of circulating miR-126. Results: The expression levels of circulating miR-126 were increased in patients with UIAs than in the healthy control. Furthermore, the expression levels of circulating miR-126 rose substantially from day 1 to day 7, but with a moderate decrease from day 7 to day 14 in plasma of patients with aSAH. The peak was observed on day 7. The AUC for miR-126 was 0.75, 0.75, 0.82, 0.87, and 0.79, respectively, and demonstrated that circulating miR-126 displayed considerable accuracy in discriminating plasma of patients with UIAs and patients after aSAH at various time points from a healthy control. Conclusion: Our results indicated that circulating miR-126 in plasma samples could be served as a potential non-invasive biomarker in IAs detection and prevention IAs with a high risk of rupture.

scholarly journals Development of Highly Sensitive Immunosensor for Clenbuterol Detection by Using Poly(3,4-ethylenedioxythiophene)/Graphene Oxide Modified Screen-Printed Carbon Electrode

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4324 ◽  
Author(s):  
Nurul Talib ◽  
Faridah Salam ◽  
Yusran Sulaiman
Keyword(s):  
Graphene Oxide ◽  
Limit Of Detection ◽  
Food Product ◽  
Electrochemical Immunosensor ◽  
Growth Promoter ◽  
Carbon Electrode ◽  
Electrochemical Assay ◽  
Sensor Platform ◽  
Screen Printed Carbon Electrode ◽  
Screen Printed

Clenbuterol (CLB) is an antibiotic and illegal growth promoter drug that has a long half-life and easily remains as residue and contaminates the animal-based food product that leads to various health problems. In this work, electrochemical immunosensor based on poly(3,4-ethylenedioxythiophene)/graphene oxide (PEDOT/GO) modified screen-printed carbon electrode (SPCE) for CLB detection was developed for antibiotic monitoring in a food product. The modification of SPCE with PEDOT/GO as a sensor platform was performed through electropolymerization, while the electrochemical assay was accomplished while using direct competitive format in which the free CLB and clenbuterol-horseradish peroxidase (CLB-HRP) in the solution will compete to form binding with the polyclonal anti-clenbuterol antibody (Ab) immobilized onto the modified electrode surface. A linear standard CLB calibration curve with R2 = 0.9619 and low limit of detection (0.196 ng mL−1) was reported. Analysis of milk samples indicated that this immunosensor was able to detect CLB in real samples and the results that were obtained were comparable with enzyme-linked immunosorbent assays (ELISA).

Serum ferritin increases after loss of igg antibodies to H. pylori; A prospective population-based cohort study comprising 1,947 danish adults

2000 ◽  
Vol 118 (4) ◽  
pp. A726
Author(s):  
Steffen J. Rosenstock ◽  
Nils Milman ◽  
Torben Joergensen ◽  
Leif P. Andersen ◽  
Olaf Bonnevie
Keyword(s):  
Cohort Study ◽  
Serum Ferritin ◽  
Population Based ◽  
Igg Antibodies ◽  
H Pylori

scholarly journals An 81-year-old patient with recent diagnosis of classic testicular seminoma

2016 ◽  
Vol 10 (2) ◽  
pp. 143
Author(s):  
Sandro José Martins ◽  
José Carlos De Almeida ◽  
Vitorino Modesto Dos Santos ◽  
Ana Carolina Vieira Cançado ◽  
Giovanna Ferraz Cavalcanti ◽  
...  
Keyword(s):  
Early Stage ◽  
Testicular Tumor ◽  
Population Based ◽  
Medical Attention ◽  
Left Testis ◽  
Testicular Seminoma ◽  
Left Testicle ◽  
First Choice ◽  
Recent Diagnosis ◽  
Radical Orchiectomy

An old patient with recent diagnosis of classic seminoma is reported. The tumor of left testicle was heralded by tenderness about 30 days before medical attention and enlarged testis confirmation. There was antecedent of left testis hypotrophy treated with testosterone and a surgery for varicocele at 15 years of age. Clinical hypothesis of testicular tumor was strengthened by ultrasonography images and elevated tumor markers (lactate dehydrogenase, <span>α</span>-fetoprotein, and <span>β</span>-hCG). Radical orchiectomy was performed and a classic seminoma (pT1pNx) was diagnosed. Active waiting was the first choice for management, but six months later a retroperitoneal mass with lymph node enlargement were found, and he underwent four sessions of carboplatin (AUC 5), bleomycin and etoposide (BEP regimen). Asymptomatic, he was referred to outpatient surveillance on Oncology. Population-based studies about frequency and outcome of early-stage testis seminoma in elderly are scarce. Case studies might contribute to the knowledge about this condition.

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