scholarly journals Serological Profile Of Specific Antibodies Against Dominant Antigens Of SARS-CoV-2 In Chilean COVID-19 Patients.

2021 ◽  
Author(s):  
K. Cereceda ◽  
R. González-Stegmaier ◽  
JL. Briones ◽  
C. Selman ◽  
A. Aguirre ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Indirect Elisa ◽  
Solid Phase ◽  
Elisa Test ◽  
Igg Antibodies ◽  
Active Infection ◽  
N Protein ◽  
Local Facility ◽  
Variable Sensitivity

ABSTRACTCoronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2 and has been a pandemic since March 2020. Currently, the virus has infected more than 50 million people worldwide and more than half a million in Chile. For many coronaviruses, Spike (S) and Nucleocapsid (N) proteins are described as major antigenic molecules, inducing seroconversion and production of neutralizing antibodies. In this work, we evaluated the presence in serum of IgM, IgA and IgG antibodies against N and S proteins of SARS-CoV-2 using western blot, and developed an ELISA test for the qualitative characterization of COVID-19 patients. Patients with an active infection or who have recovered from COVID-19 showed specific immunoblotting patterns for the recombinants S protein and its domains S1 and S2, as well as for the N protein of SARS-CoV-2. Anti-N antibodies were more frequently detected than anti-S or anti-S1-RBD antibodies. People who were never exposed to SARS-CoV-2 did not show reactivity. Finally, indirect ELISA assays using N and S1-RBD proteins, alone or in combination, were established with variable sensitivity and specificity depending on the antigen bound to the solid phase. Overall, Spike showed higher specificity than the nucleocapsid, and comparable sensitivity for both antigens. Both approaches confirmed the seroconversion after infection and allowed us to implement the analysis of antibodies in blood for research purposes in a local facility.

scholarly journals Analysis of IgG, IgA, and IgM antibodies against SARS-CoV-2 spike protein S1 in convalescent and vaccinated patients with the Pfizer-BioNTech and CanSinoBio vaccines

2021 ◽  
Author(s):  
Edgar Melgoza-González ◽  
Diana Hinojosa-Trujillo ◽  
Monica Resendiz ◽  
Verónica Mata-Haro ◽  
Sofía Hernández-Valenzuela ◽  
...  
Keyword(s):  
Indirect Elisa ◽  
Natural Infection ◽  
Rapid Development ◽  
Elisa Test ◽  
Antibody Detection ◽  
Diagnostic Tools ◽  
Igg Antibodies ◽  
The World ◽  
The One ◽  
First Time

The SARS-CoV-2 virus was detected for the first time in December 2019 in Wuhan, China. Currently, this virus has spread around the world, and new variants have emerged. This new pandemic virus provoked the rapid development of diagnostic tools, therapies and vaccines to control this new disease called COVID-19. Antibody detection by ELISA has been broadly used to recognize the number of persons infected with this virus or to evaluate the response of vaccinated individuals. As the pandemic spread, new questions arose, such as the prevalence of antibodies after natural infection and the response induced by the different vaccines. In Mexico, as in other countries, mRNA and viral-vectored vaccines have been widely used among the population. In this work, we developed an indirect ELISA test to evaluate S1 antibodies in convalescent and vaccinated individuals. By using this test, we showed that IgG antibodies against the S1 protein of SARS-CoV-2 were detected up to 42 weeks after the onset of the symptoms, in contrast to IgA and IgM, which decreased 14 weeks after the onset of symptoms. The evaluation of the antibody response in individuals vaccinated with Pfizer-BioNTech and CanSinoBio vaccines showed no differences two weeks after vaccination. However, after completing the two doses of Pfizer-BioNTech and the one dose of CanSinoBio, a significantly higher response of IgG antibodies was observed in persons vaccinated with Pfizer-BioNTech than in those vaccinated with CanSinoBio. In conclusion, these results confirm that after natural infection with SARS-CoV-2, it is possible to detect antibodies for up to ten months. Additionally, our results showed that one dose of the CanSinoBio vaccine induces a lower response of IgG antibodies than that induced by the complete scheme of the Pfizer-BioNTech vaccine.

Application of solid-phase immune electron microscopy to study physical and stability characteristics of enterically transmitted non-a, non-b hepatitis virus

1988 ◽  
Vol 46 ◽  
pp. 80-81
Author(s):  
Charles D. Humphrey ◽  
E. H. Cook ◽  
Karen A. McCaustland ◽  
Daniel W. Bradley
Keyword(s):  
Electron Microscopy ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Etiologic Agent ◽  
World Health ◽  
Health Concern ◽  
Morphological Identification ◽  
Immune Electron Microscopy

Enterically transmitted non-A, non-B hepatitis (ET-NANBH) is a type of hepatitis which is increasingly becoming a significant world health concern. As with hepatitis A virus (HAV), spread is by the fecal-oral mode of transmission. Until recently, the etiologic agent had not been isolated and identified. We have succeeded in the isolation and preliminary characterization of this virus and demonstrating that this agent can cause hepatic disease and seroconversion in experimental primates. Our characterization of this virus was facilitated by immune (IEM) and solid phase immune electron microscopic (SPIEM) methodologies.Many immune electron microscopy methodologies have been used for morphological identification and characterization of viruses. We have previously reported a highly effective solid phase immune electron microscopy procedure which facilitated identification of hepatitis A virus (HAV) in crude cell culture extracts. More recently we have reported utilization of the method for identification of an etiologic agent responsible for (ET-NANBH).

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

Characterization of Monoclonal Anti-human Factor VII Antibody (B101/B1) that Recognized Three-dimensional Structures near Arg at Position 79 in the First EGF-like Domain

1998 ◽  
Vol 79 (01) ◽  
pp. 104-109 ◽  
Author(s):  
Osamu Takamiya
Keyword(s):  
Monoclonal Antibodies ◽  
Tissue Factor ◽  
Human Factor ◽  
Solid Phase ◽  
Three Dimensional ◽  
Coagulation Factors ◽  
Factor Vii ◽  
Dimensional Structure ◽  
Epidermal Growth

SummaryMurine monoclonal antibodies (designated hVII-B101/B1, hVIIDC2/D4 and hVII-DC6/3D8) directed against human factor VII (FVII) were prepared and characterized, with more extensive characterization of hVII-B101/B1 that did not bind reduced FVIIa. The immunoglobulin of the three monoclonal antibodies consisted of IgG1. These antibodies did not inhibit procoagulant activities of other vitamin K-dependent coagulation factors except FVII and did not cross-react with proteins in the immunoblotting test. hVII-DC2/D4 recognized the light chain after reduction of FVIIa with 2-mercaptoethanol, and hVIIDC6/3D8 the heavy chain. hVII-B101/B1 bound FVII without Ca2+, and possessed stronger affinity for FVII in the presence of Ca2+. The Kd for hVII-B101/B1 to FVII was 1.75 x 10–10 M in the presence of 5 mM CaCl2. The antibody inhibited the binding of FVII to tissue factor in the presence of Ca2+. hVII-B101/B1 also inhibited the activation of FX by the complex of FVIIa and tissue factor in the presence of Ca2+. Furthermore, immunoblotting revealed that hVII-B101/B1 reacted with non-reduced γ-carboxyglutaminic acid (Gla)-domainless-FVII and/or FVIIa. hVII-B101/B1 showed a similar pattern to that of non-reduced proteolytic fragments of FVII by trypsin with hVII-DC2/D4 on immunoblotting test. hVII-B101/B1 reacted differently with the FVII from the dysfunctional FVII variant, FVII Shinjo, which has a substitution of Gln for Arg at residue 79 in the first epidermal growth factor (1st EGF)-like domain (Takamiya O, et al. Haemosta 25, 89-97,1995) compared with normal FVII, when used as a solid phase-antibody for ELISA by the sandwich method. hVII-B101/B1 did not react with a series of short peptide sequences near position 79 in the first EGF-like domain on the solid-phase support for epitope scanning. These results suggested that the specific epitope of the antibody, hVII-B101/B1, was located in the three-dimensional structure near position 79 in the first EGF-like domain of human FVII.

scholarly journals Characterization of Volatile Organic Compounds in Mango Ginger (Curcuma amada Roxb.) from Myanmar

Metabolites ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Yanhang Chen ◽  
Musavvara Kh. Shukurova ◽  
Yonathan Asikin ◽  
Miyako Kusano ◽  
Kazuo N. Watanabe
Keyword(s):  
Solid Phase ◽  
Species Variation ◽  
Mango Ginger ◽  
Food Industries ◽  
Curcuma Amada ◽  
Alternative Medicines ◽  
Flight Mass Spectrometry ◽  
Volatile Organic ◽  
Loss Of Appetite

Curcuma amada Roxb. (Zingiberaceae), commonly known as mango ginger because its rhizome and foliar parts have a similar aroma to mango. The rhizome has been widely used in food industries and alternative medicines to treat a variety of internal diseases such as cough, bronchitis, indigestion, colic, loss of appetite, hiccups, and constipation. The composition of the volatile constituents in a fresh rhizome of C. amada is not reported in detail. The present study aimed to screen and characterize the composition of volatile organic compound (VOC) in a fresh rhizome of three C. amada (ZO45, ZO89, and ZO114) and one C. longa (ZO138) accessions originated from Myanmar. The analysis was carried out by means of headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS). As a result, 122 VOCs were tentatively identified from the extracted 373 mass spectra. The following compounds were the ten most highly abundant and broadly present ones: ar-turmerone, α-zingiberene, α-santalene, (E)-γ-atlantone, cuparene, β-bisabolene, teresantalol, β-sesquiphellandrene, trans-α-bergamotene, γ-curcumene. The intensity of ar-turmerone, the sesquiterpene which is mainly characterized in C. longa essential oil (up to 15.5–27.5%), was significantly higher in C. amada accession ZO89 (15.707 ± 5.78a) compared to C. longa accession ZO138 (0.300 ± 0.08b). Cis-α-bergamotene was not detected in two C. amada accessions ZO45 and ZO89. The study revealed between-species variation regarding identified VOCs in the fresh rhizome of C. amada and C. longa.

scholarly journals Characterization of SARS-CoV-2 N protein reveals multiple functional consequences of the C-terminal domain

iScience ◽  
2021 ◽  
pp. 102681
Author(s):  
Chao Wu ◽  
Abraham J. Qavi ◽  
Asmaa Hachim ◽  
Niloufar Kavian ◽  
Aidan R. Cole ◽  
...  
Keyword(s):  
N Protein ◽  
Terminal Domain ◽  
Functional Consequences

scholarly journals Rapid seroconversion and persistent functional IgG antibodies in severe COVID-19 patients correlates with an IL-12p70 and IL-33 signature

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ariel Munitz ◽  
L. Edry-Botzer ◽  
M. Itan ◽  
R. Tur-Kaspa ◽  
D. Dicker ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Neutralizing Antibodies ◽  
Host Response ◽  
Humoral Response ◽  
Rapid Onset ◽  
Response Analysis ◽  
Receptor Binding Domain ◽  
Igg Antibodies ◽  
Viral Receptor ◽  
Iga Antibodies

AbstractDespite ongoing efforts to characterize the host response toward SARS-CoV-2, a major gap in our knowledge still exists regarding the magnitude and duration of the humoral response. Analysis of the antibody response in mild versus moderate/severe patients, using our new developed quantitative electrochemiluminescent assay for detecting IgM/IgA/IgG antibodies toward SARS-CoV-2 antigens, revealed a rapid onset of IgG/IgA antibodies, specifically in moderate/severe patients. IgM antibodies against the viral receptor binding domain, but not against nucleocapsid protein, were detected at early stages of the disease. Furthermore, we observed a marked reduction in IgM/IgA antibodies over-time. Adapting our assay for ACE2 binding-competition, demonstrated that the presence of potentially neutralizing antibodies is corelated with IgG/IgA. Finally, analysis of the cytokine profile in COVID-19 patients revealed unique correlation of an IL-12p70/IL33 and IgG seroconversion, which correlated with disease severity. In summary, our comprehensive analysis has major implications on the understanding and monitoring of SARS-CoV-2 infections.

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