scholarly journals Seroprevalence of Jamestown Canyon virus in the Japanese general population

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hirofumi Kato ◽  
Masaaki Satoh ◽  
Madoka Kawahara ◽  
Satoshi Kitaura ◽  
Tomoki Yoshikawa ◽  
...  
Keyword(s):  
General Population ◽  
Human Serum ◽  
Health Agency ◽  
Febrile Illness ◽  
Central Nervous System Disease ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Assay ◽  
Serum Samples ◽  
Human Serum Samples ◽  
Jamestown Canyon Virus

Abstract Background Jamestown Canyon virus (JCV) is a mosquito-borne orthobunyavirus that causes acute febrile illness, meningitis, and meningoencephalitis, mainly among adults. JCV is widely distributed in North America and the number of JCV cases in the U.S. has increased in recent years. Therefore, the central nervous system disease caused by JCV can be considered a potentially re-emerging viral disease. However, the seroprevalence of JCV is unknown in Japan. The purpose of this study is to evaluate the seroprevalence of JCV in the Japanese population. Methods We used an IgG enzyme-linked immunosorbent assay (IgG-ELISA) with JCV-infected cell-lysates and/or a neutralizing (NT) antibody assay. The cut-off value of IgG-ELISA was determined using IgG-ELISA to analyze serum specimens from 37 healthy Japanese donors. IgG-ELISA was validated by assessing its sensitivity and specificity, using 38 human serum samples previously tested for the presence or absence of antibodies against JCV and snowshoe hare virus (SSHV), in an in-house NT antibody assay conducted by the Public Health Agency of Canada. The seroepidemiological study was performed using IgG-ELISA and NT antibody assay to analyze 246 human serum samples from the serum bank of the National Institute of Infectious Diseases (NIID) in Japan. Results The cut-off value of IgG-ELISA was determined at 0.20, based on the mean (− 0.075) and standard deviation (0.092) values using Japanese donors’ sera. The sensitivity and the specificity of IgG-ELISA determined using 25 JCV-positive and 4 JCV-negative serum samples were 96 and 100%, respectively. Analysis of the 246 Japanese serum samples revealed that no specimen showed a higher value than the cut-off value of IgG-ELISA, and no sample tested positive by the NT antibody assay. Conclusions Our results showed that JCV is not circulating significantly in Japan. To the best of our knowledge, this is the first report to demonstrate the seroprevalence of JCV in the general population in Japan.

scholarly journals Antibody Responses to Escherichia coli O157 and Other Lipopolysaccharides in Healthy Children and Adults

2003 ◽  
Vol 10 (5) ◽  
pp. 797-801 ◽  
Author(s):  
Armando Navarro ◽  
Carlos Eslava ◽  
Ulises Hernandez ◽  
Jose Luis Navarro-Henze ◽  
Magali Aviles ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Human Serum ◽  
Western Blotting ◽  
Rabbit Serum ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Children ◽  
Serum Samples ◽  
E Coli ◽  
Human Serum Samples ◽  
Bactericidal Activities

ABSTRACT In Mexico, diarrheal disease due to different serotypes of Escherichia coli is highly prevalent, with only sporadic isolation of O157 non-H7 strains. This could be due to exposure to the O157 or related E. coli lipopolysaccharide (LPS), such as O7 or O116, at an early age. By using enzyme-linked immunosorbent assay (ELISA) and Western blotting, the present study analyzed 605 serum samples from Mexican adults and infants without clinical symptoms of disease for the presence of antibodies to these three E. coli LPSs. The bactericidal activities of homologous and heterologous rabbit and human serum samples against O7, O116, and O157 E. coli LPSs were also determined. By using a cutoff point of 0.7, it was found by the ELISAs that 28 of 562 (5%) of the serum samples from adolescents and adults and 2 of 43 (5%) of the serum samples from infants less than 1 year of age reacted with the O157 LPS. By using cutoff points between 0.4 and 0.699, the proportion of serum samples from both age groups that reacted with the O157 LPS increased to 20%. Western blotting analysis of selected serum samples that showed an intermediate response against the O157 LPS by the ELISAs showed that 61 of 88 (69%) reacted with the same LPS. A similar result was observed for maternal milk samples. The bactericidal activities of rabbit serum samples against the O7, O116, and O157 LPSs showed that they were positive for both homologous and heterologous antigens. Similar results were observed with the human serum samples. O157 non-H7 strains were identified in only 10% of the E. coli strains isolated from 263 Mexican children with and without diarrhea over the past 15 years. This absence of O157:H7 strains in Mexico may be associated with the presence of antibodies against O157 or related E. coli LPSs.

scholarly journals Inactivation ofZaire ebolavirusVariant Makona in Human Serum Samples Analyzed by Enzyme-Linked Immunosorbent Assay

2016 ◽  
Vol 214 (suppl 3) ◽  
pp. S218-S221 ◽  
Author(s):  
Todd Cutts ◽  
Allen Grolla ◽  
Shane Jones ◽  
Bradley W. M. Cook ◽  
Xiangguo Qiu ◽  
...  
Keyword(s):  
Human Serum ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Human Serum Samples

scholarly journals Performance of soluble Klotho assays in clinical samples of kidney disease

2019 ◽  
Vol 13 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Javier A Neyra ◽  
Orson W Moe ◽  
Johanne Pastor ◽  
Fabiola Gianella ◽  
Sachdev S Sidhu ◽  
...  
Keyword(s):  
Kidney Disease ◽  
Protease Inhibitor ◽  
Human Serum ◽  
Kidney Function ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Freeze Thaw ◽  
Human Serum Samples ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle

Abstract Background Soluble Klotho has multiple systemic salutary effects. In animals, both acute and chronic kidney disease models display systemic Klotho deficiency. As such, there is considerable interest in investigating soluble Klotho as a biomarker in patients with different types and severity of kidney diseases. Unfortunately, there remains uncertainty regarding the best method to measure soluble Klotho in human serum samples. Methods Using human serum samples obtained from several clinical cohorts with a wide range of kidney function, we measured soluble Klotho using a commercial enzyme-linked immunosorbent assay (ELISA) as well as with an immunoprecipitation–immunoblot (IP–IB) assay utilizing a synthetic antibody with high affinity and specificity for Klotho. Recovery of spiking with a known amount of exogenous Klotho was tested. A subset of samples was analyzed with and without the addition of a protease inhibitor cocktail at the time of collection or after the first freeze–thaw cycle to determine if these maneuvers influenced performance. Results The IP–IB assay was superior to the ELISA at recovery of exogenous Klotho (81–115% versus 60–81%) across the spectrum of kidney function. Klotho measurements by IP–IB were highly correlated with estimated glomerular filtration rate (eGFR) (R = 0.80, P < 0.001) in comparison with the commercial ELISA, which exhibited minimal correlation with eGFR (R = 0.18, P = 0.12). Use of a protease inhibitor cocktail neither improved nor impaired performance of the IP–IB assay; however, subsequent freeze–thaw cycle resulted in a significant reduction in Klotho recovery and dissipated the correlation between Klotho levels and eGFR. With the ELISA, the use of protease inhibitor cocktail resulted in an increase in intrasubject variability. Conclusions The IP–IB assay is preferable to the commercial ELISA to measure soluble Klotho concentrations in never-thawed serum samples of humans with varying severity of kidney disease. However, due to the labor-intensive nature of the IP–IB assay, further research is needed to secure an assay suitable for high-throughput work.

scholarly journals Serodiagnosis of Human Cutaneous Anthrax in India Using an Indirect Anti-Lethal Factor IgG Enzyme-Linked Immunosorbent Assay

2012 ◽  
Vol 20 (2) ◽  
pp. 282-286 ◽  
Author(s):  
N. Ghosh ◽  
I. Tomar ◽  
H. Lukka ◽  
A. K. Goel
Keyword(s):  
Early Diagnosis ◽  
Human Serum ◽  
Immunosorbent Assay ◽  
Predictive Value ◽  
Lethal Factor ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Human Serum Samples ◽  
Cutaneous Anthrax ◽  
Predictive Rate

ABSTRACTAnthrax, caused byBacillus anthracis, is primarily a zoonotic disease. Being a public health problem also in several developing countries, its early diagnosis is very important in human cases. In this study, we describe the use of an indirect enzyme-linked immunosorbent assay (ELISA) for detection of anti-lethal factor (anti-LF) IgG in human serum samples. A panel of 203 human serum samples consisting of 50 samples from patients with confirmed cutaneous anthrax, 93 samples from healthy controls from areas of India where anthrax is nonendemic, 44 samples from controls from an area of India where anthrax is endemic, and 16 patients with a disease confirmed not to be anthrax were evaluated with an anti-LF ELISA. The combined mean anti-LF ELISA titer for the three control groups was 0.136 ELISA unit (EU), with a 95% confidence interval (CI) of 0.120 to 0.151 EU. The observed sensitivity and specificity of the ELISA were 100% (95% CI, 92.89 to 100%) and 97.39% (95% CI, 93.44 to 99.28%), respectively, at a cutoff value of 0.375 EU, as decided by receiver operating characteristic (ROC) curve analysis. The likelihood ratio was found to be 49.98. The positive predictive value (PPV), negative predictive value (NPV), efficiency, and Youden's index (J) for reliability of the assay were 92.5%, 100%, 98.02%, and 0.97, respectively. The false-positive predictive rate and false-negative predictive rate of the assay were 2.61% and 0%. The assay could be a very useful tool for early diagnosis of cutaneous anthrax cases, as antibodies against LF appear much earlier than those against other anthrax toxins in human serum samples.

scholarly journals Single-step label-free nanowell immunoassay accurately quantifies serum stress hormones within minutes

2021 ◽  
Vol 7 (27) ◽  
pp. eabf4401
Author(s):  
S. Reza Mahmoodi ◽  
Pengfei Xie ◽  
Daniel P. Zachs ◽  
Erik J. Peterson ◽  
Rachel S. Graham ◽  
...  
Keyword(s):  
Human Serum ◽  
Real Time ◽  
Limit Of Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Label Free ◽  
Serum Samples ◽  
Electrode Gap ◽  
Buffer Solution ◽  
Human Serum Samples ◽  
Free Cortisol

A non-faradaic label-free cortisol sensing platform is presented using a nanowell array design, in which the two probe electrodes are integrated within the nanowell structure. Rapid and low volume (≤5 μl) sensing was realized through functionalizing nanoscale volume wells with antibodies and monitoring the real-time binding events. A 28-well plate biochip was built on a glass substrate by sequential deposition, patterning, and etching steps to create a stack nanowell array sensor with an electrode gap of 40 nm. Sensor response for cortisol concentrations between 1 and 15 μg/dl in buffer solution was recorded, and a limit of detection of 0.5 μg/dl was achieved. Last, 65 human serum samples were collected to compare the response from human serum samples with results from the standard enzyme-linked immunosorbent assay (ELISA). These results confirm that nanowell array sensors could be a promising platform for point-of-care testing, where real-time, laboratory-quality diagnostic results are essential.

Simultaneous Monitoring of Febuxostat and Uric Acid in Human Serum Samples Using the Direct Square-Wave Voltammetric Method

2019 ◽  
Vol 15 (6) ◽  
pp. 678-684
Author(s):  
Biljana Nigović ◽  
Jakov Vlak
Keyword(s):  
Uric Acid ◽  
Human Serum ◽  
Oxidase Inhibitor ◽  
Serum Samples ◽  
Boron Doped Diamond ◽  
Fast Analysis ◽  
Xanthine Oxidase Inhibitor ◽  
Voltammetric Method ◽  
Square Wave ◽  
Human Serum Samples

Background: High uric acid serum level, hyperuricemia, is now associated with many diseases such as gout, chronic kidney disease, hypertension, coronary artery disease and diabetes. Febuxostat is a novel selective xanthine oxidase inhibitor approved for the treatment of hyperuricemia. Objective: The aim of this study was to develop a first analytical method for the simultaneous determination of febuxostat and uric acid. Methods: An unmodified boron-doped diamond electrode provided concurrent quantitation of drug at low levels and uric acid, which has clinical significance in the diagnosis and therapy of hyperuricemia, at relatively high concentrations. The direct square-wave voltammetric method was applied to the analysis of both analytes in human serum samples. Results: Under the optimized conditions, the linear response of peak current on febuxostat concentration was achieved in the range from 7.5 × 10-7 to 3 × 10-5 M, while uric acid showed two linear ranges of 5 × 10-6 - 5 × 10-5 M and 5 × 10-5 - 2 × 10-4 M. The method was successfully utilised for quantification of both analytes in human serum samples. Good recoveries were obtained without interference from common inorganic cations and anions as well as glucose, dopamine, ascorbic and folic acids at concentrations expected in physiological conditions. Conclusion: The great benefits of developed method are fast analysis (only 7.5 s for run), low cost and simplicity of performance.

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