scholarly journals Bayesian Binary Mixture Models as a Flexible Alternative to Cut-Off Analysis of ELISA Results, a Case Study of Seoul Orthohantavirus

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1155
Author(s):  
Arno Swart ◽  
Miriam Maas ◽  
Ankje de Vries ◽  
Tryntsje Cuperus ◽  
Marieke Opsteegh
Keyword(s):  
Binary Mixture ◽  
Mixture Models ◽  
Mixture Model ◽  
Optical Density ◽  
Quantitative Polymerase Chain Reaction ◽  
Optimal Solution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Analysis Tool ◽  
Distribution Of Values ◽  
Serological Data

Serological assays, such as the enzyme-linked immunosorbent assay (ELISA), are popular tools for establishing the seroprevalence of various infectious diseases in humans and animals. In the ELISA, the optical density is measured and gives an indication of the antibody level. However, there is variability in optical density values for individuals that have been exposed to the pathogen of interest, as well as individuals that have not been exposed. In general, the distribution of values that can be expected for these two categories partly overlap. Often, a cut-off value is determined to decide which individuals should be considered seropositive or seronegative. However, the classical cut-off approach based on a putative threshold ignores heterogeneity in immune response in the population and is thus not the optimal solution for the analysis of serological data. A binary mixture model does include this heterogeneity, offers measures of uncertainty and the direct estimation of seroprevalence without the need for correction based on sensitivity and specificity. Furthermore, the probability of being seropositive can be estimated for individual samples, and both continuous and categorical covariates (risk-factors) can be included in the analysis. Using ELISA results from rats tested for the Seoul orthohantavirus, we compared the classical cut-off method with a binary mixture model set in a Bayesian framework. We show that it performs similarly or better than cut-off methods, by comparing with real-time quantitative polymerase chain reaction (RT-qPCR) results. We therefore recommend binary mixture models as an analysis tool over classical cut-off methods. An example code is included to facilitate the practical use of binary mixture models in everyday practice.

scholarly journals Estimating dengue transmission intensity from serological data: a comparative analysis using mixture and catalytic models.

2021 ◽  
Author(s):  
Victoria M Cox ◽  
Megan M O'Driscoll ◽  
Natsuko Imai ◽  
Ari Prayitno ◽  
Sri Rezeki Hadinegoro ◽  
...  
Keyword(s):  
Mixture Models ◽  
Mixture Model ◽  
Time Constant ◽  
Binary Classification ◽  
Simulated Data ◽  
Real Data ◽  
Denv Infection ◽  
Health Concern ◽  
Time Varying ◽  
Serological Data

Background. Dengue virus (DENV) infection is a global health concern of increasing magnitude. To target intervention strategies, accurate estimates of the force of infection (FOI) are necessary. Catalytic models have been widely used to estimate DENV FOI and rely on a binary classification of serostatus as seropositive or seronegative, according to pre-defined antibody thresholds. Previous work has demonstrated the use of thresholds can cause serostatus misclassification and biased estimates. In contrast, mixture models do not rely on thresholds and use the full distribution of antibody titres. To date, there has been limited application of mixture models to estimate DENV FOI. Methods. We compare the application of mixture models and time-constant and time-varying catalytic models to simulated data and to serological data collected in Vietnam from 2004 to 2009 (N ≥ 2178) and Indonesia in 2014 (N = 3194). Results. The simulation study showed greater estimate bias from the time-constant and time-varying catalytic models (FOI bias = 1.3% (0.05%, 4.6%) and 2.3% (0.06%, 7.8%), seroprevalence bias = 3.1% (0.25%, 9.4%) and 2.9% (0.26%, 8.7%), respectively) than from the mixture model (FOI bias = 0.41% (95% CI 0.02%, 2.7%), seroprevalence bias = 0.11% (0.01%, 3.6%)). When applied to real data from Vietnam, the mixture model frequently produced higher FOI and seroprevalence estimates than the catalytic models. Conclusions. Our results suggest mixture models represent valid, potentially less biased, alternatives to catalytic models, which could be particularly useful when estimating FOI and seroprevalence in low transmission settings, where serostatus misclassification tends to be higher.

scholarly journals Exploratory field study on the effects of porcine circovirus 2 (PCV-2) sow vaccination at different physiological stages mimicking blanket vaccination

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Patricia Pleguezuelos ◽  
Marina Sibila ◽  
Raúl Cuadrado ◽  
Rosa López-Jiménez ◽  
Diego Pérez ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Negative Control Group ◽  
Negative Control ◽  
Late Gestation ◽  
Antibody Detection ◽  
Porcine Circovirus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Physiological Status ◽  
Porcine Circovirus 2

Abstract Background The objective of the present study was to explore the benefits of Porcine circovirus 2 (PCV-2) blanket vaccination in a sow herd on productive parameters, PCV-2 infection and immune status in sows and their progeny. For this purpose, 288 sows were distributed among four balanced experimental groups. One group remained as negative control group and the other three received 1 mL of PCV-2 Ingelvac Circoflex® intramuscularly at different productive cycle moments: before mating, mid gestation (42–49 days post-insemination) or late gestation (86–93 days post-insemination); phosphate buffered saline (PBS) was used as negative control item. Reproductive parameters from sows during gestation and body weight of their progeny from birth to weaning were recorded. Additionally, blood was collected from sows at each vaccination time and piglets at 3 weeks of age. Moreover, up to 4 placental umbilical cords (PUC) per sow were taken at peri-partum. Sera from sows and piglets were analysed for PCV-2 antibody detection using an enzyme-linked immunosorbent assay (ELISA). Sera from sows and PUC were tested to quantify viraemia using a real time quantitative polymerase chain reaction (qPCR) assay. Results Globally, results indicated that vaccinated sows showed heavier piglets at birth and at weaning, less cross-fostered piglets, lower viral load at farrowing as well as in PUC, and higher antibody levels at farrowing, compared to non-vaccinated ones. When all groups were compared among them, sows vaccinated at mid or late gestation had heavier piglets at birth than non-vaccinated sows, and lower proportion of PCV-2 positive PUC. Also, cross-fostering was less frequently practiced in sows vaccinated at pre-mating or mid gestation compared to non-vaccinated ones. Conclusions In conclusion, the present study points out that PCV-2 sow vaccination at different time points of their physiological status (mimicking blanket vaccination) offers benefits at production and serological and virological levels.

scholarly journals Long non-coding RNA OIP5-AS1 aggravates acute lung injury by promoting inflammation and cell apoptosis via regulating the miR-26a-5p/TLR4 axis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qingsong Sun ◽  
Man Luo ◽  
Zhiwei Gao ◽  
Xiang Han ◽  
Weiqin Wu ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Inflammatory Response ◽  
Cell Apoptosis ◽  
Quantitative Polymerase Chain Reaction ◽  
Luciferase Reporter ◽  
Enzyme Linked Immunosorbent Assay ◽  
Interacting Protein ◽  
Wide Range

Abstract Background Acute lung injury (ALI) is a pulmonary disorder that leads to acute respiration failure and thereby results in a high mortality worldwide. Increasing studies have indicated that toll-like receptor 4 (TLR4) is a promoter in ALI, and we aimed to explore the underlying upstream mechanism of TLR4 in ALI. Methods We used lipopolysaccharide (LPS) to induce an acute inflammatory response in vitro model and a murine mouse model. A wide range of experiments including reverse transcription quantitative polymerase chain reaction, western blot, enzyme linked immunosorbent assay, flow cytometry, hematoxylin–eosin staining, RNA immunoprecipitation, luciferase activity and caspase-3 activity detection assays were conducted to figure out the expression status, specific role and potential upstream mechanism of TLR4 in ALI. Result TLR4 expression was upregulated in ALI mice and LPS-treated primary bronchial/tracheal epithelial cells. Moreover, miR-26a-5p was confirmed to target TLR4 according to results of luciferase reporter assay. In addition, miR-26a-5p overexpression decreased the contents of proinflammatory factors and inhibited cell apoptosis, while upregulation of TLR4 reversed these effects of miR-26a-5p mimics, implying that miR-26a-5p alleviated ALI by regulating TLR4. Afterwards, OPA interacting protein 5 antisense RNA 1 (OIP5-AS1) was identified to bind with miR-26a-5p. Functionally, OIP5-AS1 upregulation promoted the inflammation and miR-26a-5p overexpression counteracted the influence of OIP5-AS1 upregulation on cell inflammatory response and apoptosis. Conclusion OIP5-AS1 promotes ALI by regulating the miR-26a-5p/TLR4 axis in ALI mice and LPS-treated cells, which indicates a promising insight into diagnostics and therapeutics in ALI.

scholarly journals miR-128-3p inhibits apoptosis and inflammation in LPS-induced sepsis by targeting TGFBR2

Open Medicine ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 274-283
Author(s):  
Peng Yang ◽  
Jianhua Han ◽  
Shigeng Li ◽  
Shaoning Luo ◽  
Xusheng Tu ◽  
...  
Keyword(s):  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Quantitative Polymerase Chain Reaction ◽  
Luciferase Reporter ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Aberrant Expression ◽  
Protein Levels ◽  
Apoptosis And Inflammation ◽  
Hk2 Cells

Abstract Background Sepsis is a systemic inflammatory response that can lead to the dysfunction of many organs. The aberrant expression of miRNAs is associated with the pathogenesis of sepsis. However, the biological functions of miR-128-3p in sepsis remain largely unknown, and its mechanism should be further investigated. This study aimed to determine the regulatory network of miR-128-3p and TGFBR2 in lipopolysaccharide (LPS)-induced sepsis. Methods The expression levels of miR-128-3p and transforming growth factor beta receptors II (TGFBR2) were detected by quantitative polymerase chain reaction (qPCR). The protein levels of TGFBR2, Bcl-2, Bax, cleaved caspase 3, Smad2, and Smad3 were measured by western blot. Cell apoptosis was analyzed by flow cytometry. Cytokine production was detected by enzyme-linked immunosorbent assay (ELISA). The binding sites of miR-128-3p and TGFBR2 were predicted by Targetscan online software and confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Results The level of miR-128-3p was decreased, and TGFBR2 expression was increased in serum samples of sepsis patients and LPS-induced HK2 cells. Overexpression of miR-128-3p or knockdown of TGFBR2 ameliorated LPS-induced inflammation and apoptosis. Moreover, TGFBR2 was a direct target of miR-128-3p, and its overexpression reversed the inhibitory effects of miR-128-3p overexpression on inflammation and apoptosis in LPS-induced HK2 cells. Besides, overexpression of miR-128-3p downregulated TGFBR2 to suppress the activation of the Smad signaling pathway. Conclusion miR-128-3p could inhibit apoptosis and inflammation by targeting TGFBR2 in LPS-induced HK2 cells, which might provide therapeutic strategy for the treatment of sepsis.

scholarly journals 2109

2017 ◽  
Vol 1 (S1) ◽  
pp. 1-1
Author(s):  
Stephanie Davis ◽  
Jeffrey Huang
Keyword(s):  
Mononuclear Cells ◽  
Age Of Onset ◽  
Quantitative Polymerase Chain Reaction ◽  
Study Groups ◽  
Interleukin 4 ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peripheral Blood Mononuclear ◽  
Repair Capacity ◽  
Relapsing Remitting ◽  
Inflammatory Profile

OBJECTIVES/SPECIFIC AIMS: The overall objective of this proposal is to establish and modulate the inflammatory profile of individuals across the spectrum of multiple sclerosis (MS), with a focus on determining the potential of interleukin 4-induced protein 1 (IL4I1) as a possible marker of progression and modulator of inflammation in human blood samples. METHODS/STUDY POPULATION: The proposed experimental approach involves isolating plasma and peripheral blood mononuclear cells (PBMCs) from individuals across the spectrum of MS phenotypes, and analyzing these samples primarily by quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA) methods. Specifically, study groups include: (1) actively relapsing-remitting MS (a-RRMS), (2) non-actively relapsing-remitting MS (n-RRMS), (3) non-active secondary-progressive MS (SPMS), (4) other autoimmune diseases (OAD), (5) healthy controls (HC). RESULTS/ANTICIPATED RESULTS: We expect that IL4I1 treatment increases regulatory cytokine (eg, IL10, TGFb) expression while decreasing Th1 and Th17-derived cytokines (IFNg, IL17), as well as increasing relative composition of regulatory cells (Th2, Treg, M2) as compared with Th1, Th17, M1 (aim 1). Preliminary data on healthy control cells support this prediction. Our central hypothesis is that IL4I1 level indicates the body’s ability to repair itself. As such, we anticipate that all MS groups are deficient in IL4I1, to varying degrees, such that HC>n-RRMS>a-RRMS>SPMS. HC have full repair capacity. RRMS>SPMS as remission indicates existent repair capacity, which is lost in SPMS. n-RRMS>a-RRMS since both, as RRMS, capable of repair response, but a-RRMS triggered this response more recently in response to more recent relapse. In all groups, we expect IL4I-treatment to mitigate inflammation (aim 2). Finally, we expect that H2O2 production by IL4I1 is a key player in IL4I1 function, and that H2O2 will preferentially induce oxidative stress to pro-inflammatory subsets of PBCMs (aim 3). DISCUSSION/SIGNIFICANCE OF IMPACT: MS is a chronic inflammatory neurodegenerative disease of the central nervous system that, with an average age of onset of 34, afflicts over 2.3 million individuals worldwide during many of the most productive years of their lives. The pathogenesis of MS, which involves autoimmune destruction of myelin, is poorly understood. Accurate biomarkers, which could predict disease progression, are yet to be identified and would provide valuable information to patients and their treating clinicians. Likewise, effective treatments are few and in high demand. IL4I1 is a promising candidate for both roles.

scholarly journals The Absence of TLR4 Prevents Fetal Brain Injury in the Setting of Intrauterine Inflammation

2018 ◽  
Vol 26 (8) ◽  
pp. 1082-1093 ◽  
Author(s):  
Natalia M. Tulina ◽  
Amy G. Brown ◽  
Guillermo O. Barila ◽  
Michal A. Elovitz
Keyword(s):  
Brain Injury ◽  
Notch Signaling ◽  
Signaling Pathway ◽  
Quantitative Polymerase Chain Reaction ◽  
Fetal Brain ◽  
Notch Signaling Pathway ◽  
Mouse Strains ◽  
Enzyme Linked Immunosorbent Assay ◽  
Tlr4 Signaling ◽  
Tlr4 Signaling Pathway

Background: Exposure to intrauterine inflammation during pregnancy is linked to brain injury and neurobehavioral disorders in affected children. Innate immunity, specifically Toll-like receptor (TLR) signaling pathways are present throughout the reproductive tract as well as in the placenta, fetal membranes, and fetus. The TLR pathways are mechanistically involved in host responses to foreign pathogens and may lead to brain injury associated with prenatal inflammation. Objective: We aimed to determine whether the activation of the TLR4 signaling pathway, in the mother and fetus, is critical to fetal brain injury in the setting of intrauterine inflammation. Methods: A mini-laparotomy was performed on time pregnant C57B6 mice and 2 knockout mouse strains lacking the function of the Tlr4 and Myd88 genes on embryonic day 15. Intrauterine injections of Escherichia coli lipopolysaccharide or saline were administered as described previously. Dams were killed 6 hours postsurgery, and placental, amniotic fluid, and fetal brain tissue were collected. To assess brain injury, quantitative polymerase chain reaction (qPCR) analysis was performed on multiple components of the NOTCH signaling pathway, including Hes genes. Interleukin (IL) IL6, IL1β, and CCL5 expression was assessed using qPCR and enzyme-linked immunosorbent assay. Results: Using an established mouse model of intrauterine inflammation, we demonstrate that the abrogation of TLR4 signaling eliminates the cytokine response in mother and fetus and prevents brain injury associated with increased expression of transcriptional effectors of the NOTCH signaling pathway, Hes1 and Hes5. Conclusions: These data show that the activation of the TLR4 signaling pathway is necessary for the development of fetal brain injury in response to intrauterine inflammation.

scholarly journals Down-regulation of MAPK pathway alleviates TRPV4-mediated trigeminal neuralgia by inhibiting the activation of histone acetylation

2021 ◽  
Author(s):  
Weidong Liu ◽  
Benfang Pu ◽  
Mindi Liu ◽  
Xuejun Zhang ◽  
Ran Zeng
Keyword(s):  
Trigeminal Neuralgia ◽  
Western Blot ◽  
Histone Acetylation ◽  
Transient Receptor Potential ◽  
Mapk Pathway ◽  
Quantitative Polymerase Chain Reaction ◽  
Infraorbital Nerve ◽  
Enzyme Linked Immunosorbent Assay ◽  
Transient Receptor Potential Vanilloid ◽  
Down Regulation

AbstractOur objective of this study is to determine the molecular mechanism of MAPKs (mitogen activated protein kinase systems) on TRPV4 (transient receptor potential vanilloid 4)-mediated trigeminal neuralgia (TN). Partial chronic constriction injury of the infraorbital nerve (CCI-ION) ligation model was used in this research. When treated with antagonists of p38, JNK or ERK, the mechanical hyperalgesia threshold, nerve fiber disorder, myelinoclasis, and Schwann cells proliferation could be reversed. RT-PCR (real-time quantitative polymerase chain reaction), Western blot and IHC (immunohistochemistry) showed that TRPV4 mRNA and protein levels, TRPV4-positive cells and small positive neurons decreased remarkably in TN group treated with antagonists of p38, JNK or ERK. ELISA (enzyme-linked immunosorbent assay) was performed to discover inhibition of MAPK pathway can down-regulate the expression of HATs (histone acetyltransferases), and up-regulate the expression of HDACs (histone deacetylases) in TN, thus inhibiting histone acetylation. Finally, Western blot was performed to identify the phosphorylation status of p38, JNK and ERK, finding decreased phosphorylation forms in antagonists treated TN groups compared with TN groups. Based on the above investigation method, on a whole, our study showed that down-regulation of MAPK pathway could alleviate TRPV4-mediated trigeminal neuralgia, via inhibiting the activation of histone acetylation.

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