Enzyme-linked Immunosorbent Assay Procedure Research Articles

Revolutionizing ELISA: A one-step blocking approach using lipid bilayer coatings

Enzyme-linked immunosorbent assay (ELISA) is an essential technique for biomolecule detection in diagnostics and research, but traditional protocols are time-consuming and variable. Conventional blocking agents like bovine serum albumin (BSA) pose ethical issues and potential assay interference. This study presents a one-step lipid-blocking approach to simplify the ELISA procedure. Compared to conventional blockers, the Lipid Universal Coating Assembly (LUCA) antifouling blocker showed comparable sensitivity while significantly reducing processing time and steps. Furthermore, it showed improved co-blocking efficacy and signal intensity in conventional protocols when combined with minimal BSA concentrations. Stability tests under accelerated aging confirmed the robustness of the LUCA antifouling blocker. Additionally, it effectively facilitated antibody detection for COVID-19 antigens in direct ELISA and human IL-6 antigen in Sandwich ELISA, suggesting its versatile applicability. Taken together, our findings reveal that one-step lipid blocking not only streamlines the ELISA process but also maintains high sensitivity and specificity, providing an efficient, user-friendly, and environmentally friendly alternative to traditional ELISA blockers and a robust platform for rapid diagnostics.

A Highly Sensitive and Group-Specific Enzyme-Linked Immunosorbent Assay (ELISA) for the Detection of AFB1 in Agriculture and Aquiculture Products.

Aflatoxins (AFs) including AFB1, AFB2, AFG1 and AFG2 are widely found in agriculture products, and AFB1 is considered one of the most toxic and harmful mycotoxins. Herein, a highly sensitive (at the pg mL-1 level) and group-specific enzyme-linked immunosorbent assay (ELISA) for the detection of AFB1 in agricultural and aquiculture products was developed. The AFB1 derivative containing a carboxylic group was synthesized and covalently linked to bovine serum albumin (BSA). The AFB1-BSA conjugate was used as an immunogen to immunize mice. A high-quality monoclonal antibody (mAb) against AFB1 was produced by hybridoma technology, and the mAb-based ELISA for AFB1 was established. IC50 and limit of detection (LOD) of the ELISA for AFB1 were 90 pg mL-1 and 18 pg mL-1, respectively. The cross-reactivities (CRs) of the assay with AFB2, AFG1, and AFG2 were 23.6%, 42.5%, and 1.9%, respectively, revealing some degree of group specificity. Corn flour, wheat flour, and crab roe samples spiked with different contents of AFB1 were subjected to ELISA procedures. The recoveries and relative standard deviation (RSD) of the ELISA for AFB1 in spiked samples were 78.3-116.6% and 1.49-13.21% (n = 3), respectively. Wheat flour samples spiked with the mixed AF (AFB1, AFB2, AFG1, AFG2) standard solution were measured by ELISA and LC-MS/MS simultaneously. It was demonstrated that the proposed ELISA can be used as a screening method for evaluation of AFs (AFB1, AFB2, AFG1, AFG2) in wheat flour samples.

Pollen allergen products: current standardisation issues

Scientific relevance. Pollen allergen medicines are in high demand, and their therapeutic benefits directly correlate with their standardisation. Better diagnosis and treatment of allergic diseases require state-of-the-art procedures for assessing the allergenic activity of pollen allergen products using reference standards and physicochemical testing methods.Aim. The study aimed at developing methodological approaches to the standardisation of pollen allergen products in order to shift to measuring their potency in allergenic activity units (AAU) and bring their quality in line with the requirements of the State Pharmacopoeia of the Russian Federation.Materials and methods. The study used pollen allergen reference standards by Microgen, the WHO International Standard for timothy grass (Phleum pratense) pollen extract, a gel filtration standard kit of molecular weight markers ranging from 1.35 to 670 kDa, bovine serum albumin, serum samples with specific IgE obtained from donors sensitised to the study pollen allergens, labelled anti-human IgE antibodies, and reference standards for determining residual volatile solvents by gas chromatography. The identification of in-house reference standards for the potency of pollen allergens involved Western blotting (for allergenic components). The total protein content was determined by Bradford’s assay. In addition, the authors used high-performance liquid chromatography to study protein fractions and gas–liquid chromatography to determine the content of residual organic solvents.Results. To substitute the existing method of non-specific characterisation of allergenic activity in protein nitrogen units (PNU), the authors developed and tested a new method to control allergenic activity in allergenic activity units (AAU) based on an in vitro competitive enzyme-linked immunosorbent assay (ELISA) procedure developed and validated in this study. Furthermore, the authors developed and certified 15 primary in-house reference standards with allergenic activity established in AAU/mL using skin tests in vivo. The experimental data were analysed to standardise the allergenic activity of the pollen allergens manufactured by Microgen. The authors developed physicochemical methods for the certification of in-house reference standards and validated these methods in accordance with the State Pharmacopoeia of the Russian Federation. The study involved selecting chromatographic separation conditions for residual organic solvents (acetone and diethyl ether) and establishing system suitability criteria for the chromatographic system. The allergenic activity of secondary in-house reference standards was certified against that of primary in-house reference standards using competitive ELISA. Thus, the authors managed to shift to the standardisation of pollen allergen products in vitro.Conclusions. The authors developed their competitive ELISA-based method to standardise pollen allergen products by comparing the inhibition of immune responses to a product and a standard. The study demonstrated the feasibility of substituting allergenic activity quantification (in AAU) for protein nitrogen content determination (in PNU) and showed the first example of using AAU for the certification of in-house reference standards. Additionally, the authors developed and validated an analytical procedure for determining the content of residual organic solvents in pollen allergen products by gas–liquid chromatography.

Determination of Prostate Specific Antigen Level among Male Patients with Bacterial Urinary Tract Infections Attending Kuje General Hospital Abuja, Nigeria

Recent hospital and cancer registry data shows increasing prostate cancer incidence in Nigeria, which was previously regarded as a low incidence region. Prostate cancer is the leading cause of cancer death among men in Nigeria and second most common cancers of men worldwide and sexual history has been a consistent risk factor. Prostate specific antigen (PSA) test is still the single most important test for early detection of prostate cancer worldwide. However, not much is reported about prostate cancer in relation to urinary tract infections in Africa. This study investigates the prevalence of prostate cancer risk in and bacterial urinary tract infections among men in Abuja, Nigeria. One Hundred (100) samples each of blood and urine were collected, from fifty (50) male patients suffering from urinary tract infections and fifty (50) apparently healthy males attending Kuje General Hospital Abuja, Nigeria. All the blood samples were subjected to PSA analysis using Enzyme-linked Immunosorbent Assay procedure (Diagnostic Automation/ Cortez Diagnostics, Inc, USA) while urine analysis (microscopy, culture and biochemical identification) was performed on the urine to isolate and identify the common bacteria associated with urinary tract infections among the study population.

Sandwich Enzyme-linked Immunosorbent Assay (ELISA) to Quantify Monoclonal Antibody (B[a]P-13) for Herbal Medicine Products

Abstract: Sandwich enzyme-linked immunosorbent assay (ELISA) to quantify monoclonal antibody (B[a]P-13) Background: Only a few studies have focused on the analysis using specific antibodies in the sandwich ELISA method to each B[a]P in herbal medicine products. In contrast to the sandwich ELISA method, many competitive ELISA methods using specific antibodies such as benzo[a]pyrene monoclonal antibody (B[a]P-13) and a goat anti-mouse IgG (H+L) cross-adsorbed secondary antibody, horseradish peroxidase (HRP) were developed. Introduction: The objective of this study was to develop and validate the method for the response of the benzo[a]pyrene monoclonal antibody (B[a]P-13) and goat anti-mouse IgG (H+L) cross-adsorbed secondary antibody (HRP) to prepare the immunogen and its application to detect the benzo[a]pyrene in various herbal medicine products. Methods: This research method includes preparation of B[a]P-protein conjugates, sampling and extraction procedure for herbal medicines, sandwich ELISA procedure, evaluation of cross-reactivity for determination, matrix effect of the organic solvents, correlation of benzo[a]pyrene detection ELISA compared to HPLC-FLD in herbal medicine products. Results: The sandwich ELISA method for B[a]P was validated in linearity (R2 > 0.99), the limit of detection (LOD) (0.080.19 μg/kg) and limit of quantification (LOQ) (0.240.57 μg/kg), accuracy (95.58117.06 %), and precision (3.8010.26 %). The cross-reactivity (CR) was found for B[a]P (100%), CHR (39%), B[b]F (27%), and B[a]A (41%). As a solvent, acetonitrile (MeCN) was used to express the normalized sandwich ELISA calibration curves with benzo[a]pyrene monoclonal antibody (B[a]P-13). The antigen-antibody binding in sandwich ELISA was decreased about 10 times with increasing the salt content (0.0060.18 mol/L phosphate to 20400 mmol/L). The pH range from 6 to 9 was not considered to affect the performance of the sandwich ELISA. Correlation of B[a]P detection in herbal medicines with ELISA compared to HPLC-FLD expressed good correlation (R2 = 0.991) and the slope of the graph for the ELISA (B[a]P-equivalents μg/kg) value divided by the HPLC-FLD (B[a]P μg/kg) value was 0.7292. Conclusion: Therefore, sandwich ELISA method using benzo[a]pyrene monoclonal antibody (B[a]P-13) could be an alternative screening method for detection of B[a]P in herbal medicine products.

Estimation of L-carnitine levels in diabetic completely edentulous patients for implant diagnosis: A cross-sectional study

Background: Carnitine is effective in preventing the accumulation of end products related to lipid peroxidation due to its anti-inflammatory and antioxidant effects. Carnitine also exerts a significant anti-inflammatory role through the downregulation of the nuclear factor kappa beta pathway, which leads to a decrease in the expression of pro-inflammatory cytokines. The aim of the study was to estimate the L-carnitine (L-C) levels in diabetic completely edentulous patients. Materials and Methods: A cross-sectional study was conducted after the selection of 60 samples based on the inclusion and exclusion criteria. The collected saliva samples were utilized to measure the levels of L-C using the sandwich enzyme-linked immunosorbent assay (ELISA) method. One hundred microliters of sample was applied to a particular row of wells and incubated for an hour as part of the sandwich ELISA procedure. After the wells had been cleaned, a second batch of monoclonal L-C was added, and they were once more incubated for an hour. The horseradish peroxidase substrate was then applied after washing the second batch as well. To allow the blue-to-yellow color transition, the wells were kept steady. Following the observation of the color shift, the OD was measured, and the concentration was determined using the sandwich ELISA kit's standard curve as an intercept. The data were statistically analyzed using the independent t-test (significant level P < 0.05) and were tabulated. Results: The L-C levels have higher levels in nondiabetic patients than in diabetic patients. The difference in the baseline mean value between the groups was statistically significant (P = 0.00). Although it is statistically significant (P = 0.00), the mean value for diabetic individuals is 0.19 as opposed to 0.29 for nondiabetic patients. Conclusion: Based on the findings, it can be concluded that L-C improves insulin sensitivity and glucose disposal in diabetic completely edentulous patients.

Ultrasensitive plasmonic photothermal immunomagnetic bioassay using real-time and end-point dual-readout

One of the most straightforward and sensitive methods for combining the specificity of immunological recognition with the amplification capability of polymerase chain reaction (PCR) is the fluorescence-based immuno-PCR. But up until now, the majority of PCR-based immunoassays have utilized the pricey and lengthy Peltier-based heating technique. Herein, we introduce a plasmonic photothermal quantitative immuno-PCR (PPT-qiPCR) assay with real-time and end-point dual readout for biomarker detection using multifunctional plasmonic immunomagnetic nanoparticles (PIMNs). PPT-qiPCR is simple, time-saving and inexpensive compared with conventional iPCR platforms using PCR machine. We showed that an immunomagnetic technique utilizing PIMNs can shorten the time needed for collection, washing, and concentrating target proteins in the enzyme-linked immunosorbent assay (ELISA) procedure. Real-time readout also permits quick preliminary discrimination of target proteins with apparent sensitivity in commercial ELISA investigations. Additionally, in-situ end-point fluorescence or colorimetric detection using only the human eye considerably improve the assay sensitivity. Our PPT-qiPCR can significantly advance next-generation point-of-care molecular diagnostic technology and is anticipated to be immediately useful for the sensitive and quick identification of several disease biomarkers.

Combined Antibody Tagged HRP Gold Nanoparticle Probe for Effective PCV2 Screening in Pig Farms.

IntroductionPorcine circovirus type 2 (PCV2) causes immune repression and intercurrent infections in pigs, resulting in a huge economic loss to the pig breeding industry. Additionally, the spread of PCV2 in pig farms can pollute the living environment of the residents in the farm’s vicinity, which increases the rate of infections. Therefore, rapid and sensitive detection methods are needed for disease prevention and timely environmental cleaning.MethodsThis research describes a highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA) that utilizes gold nanoparticles (AuNPs) in a functional, specific antibody labeled probe for the detection of PCV2. Due to their high specific surface area and histocompatibility, AuNPs were used as carriers of HRP labeled anti-PCV2 antibodies to amplify the detection signal.ResultsCompared to conventional sandwich ELISA procedures, this method resulted in higher sensitivity (51-fold) and a shorter assay time with a limit of detection of 195 TCID50/mL. The cross-reactivity assay demonstrated that this assay was PCV2 specific.ConclusionThe amplified Ab (HRP) labeled AuNPs probe provides a sensitive analytical approach for the determination of the traces of the PCV2 antigen in early diagnosis.

Toxoplasma gondii Infection and Aggression in Autistic Children.

Toxoplasmosis is an infectious disease caused by the obligatory intracellular parasite Toxoplasma gondii. The main aim of this study was to evaluate a possible relationship between aggression in autistic children with infection by T. gondii. The research design was an analytical (comparative) cross sectional study. The participants included (N = 100) subjects (50 autistic and 50 normal children) between 3 and 12 years old. They were matched for age, socioeconomic status, lack of physical and mental illness. The instruments were preschool aggression scale and enzyme-linked immunosorbent assay procedure to essay the blood sample test. Five milliliters of blood samples were collected to assess the presence of T. gondii infection. The results showed that autistic children had a higher rate of infection by T. gondii than normal children. Furthermore, children infected with T. gondii were more aggressive than the noninfected group. In autistic children, T. gondii infection was significantly higher than in the normal group. Also, autistic children who were infected with the parasite were more aggressive.

Detection of Antibodies to Human T Cell Lymphotrophic Virus-I/II and Strongyloides Stercoralis Among Pregnant Women on Antenatal Visits to Selected Hospitals in Jos, Nigeria

Human T cell Lymphotrophic Virus (HTLV-I/II) is an oncogenic retrovirus known to cause adult T cell leukemia which is transmitted vertically from mother to child and sexually by infected lymphocytes. Studies suggest that the onset of adult T-cell leukemia/lymphoma (ATL) in patients infected with HTLV-I/II occurs significantly earlier when the subjects are coinfected with S. stercoralis. This study was aimed at detecting antibodies to HTLV-I/II and Strongyloides stercoralis larvae among pregnant women on antenatal visits to selected hospitals in Jos, Nigeria. A total of 188 blood samples and 136 stool samples were collected for study. Five milliliters (5ml) of venous blood was collected and transferred into a screw capped plastic tube without anticoagulant and sera extracted from each participant’s sample and later analyzed for antibodies to HTLV-I/II using double-antigen sandwich enzyme linked immunosorbent assay (ELISA) kit. Stool samples were also analyzed using direct stool microscopy and Baemanns technique. Questionnaires were administered for participants’ demographics and assessment of risk factors. Data obtained were then analyzed using SPSS version 17. Human T cell Lymphotrophic Virus –I/II prevalence of 2.13% (4/188) was detected following the ELISA procedures with 1.06% (2/188) indeterminate results. Risk factors assessed had no statistical association with HTLV-I/II infection except for history of cancer in a family. Five parasite species were detected on stool examination with 2.2% prevalence of Strongyloides stercoralis. Keeping of pet dogs and having itching around legs were statistically associated with Strongyloidiasis (P< 0.05). Routine monitoring of HTLV-I/II and dewormming of pregnant women on antenatal should be a matter of priority.

Sample-to-Answer Robotic ELISA.

Enzyme-linked immunosorbent assays (ELISA), as one of the most used immunoassays, have been conducted ubiquitously in hospitals, research laboratories, etc. However, the conventional ELISA procedure is usually laborious, occupies bulky instruments, consumes lengthy operation time, and relies considerably on the skills of technicians, and such limitations call for innovations to develop a fully automated ELISA platform. In this paper, we have presented a system incorporating a robotic-microfluidic interface (RoMI) and a modular hybrid microfluidic chip that embeds a highly sensitive nanofibrous membrane, referred to as the Robotic ELISA, to achieve human-free sample-to-answer ELISA tests in a fully programmable and automated manner. It carries out multiple bioanalytical procedures to replace the manual steps involved in classic ELISA operations, including the pneumatically driven high-precision pipetting, efficient mixing and enrichment enabled by back-and-forth flows, washing, and integrated machine vision for colorimetric readout. The Robotic ELISA platform has achieved a low limit of detection of 0.1 ng/mL in the detection of a low sample volume (15 μL) of chloramphenicol within 20 min without human intervention, which is significantly faster than that of the conventional ELISA procedure. Benefiting from its modular design and automated operations, the Robotic ELISA platform has great potential to be deployed for a broad range of detections in various resource-limited settings or high-risk environments, where human involvement needs to be minimized while the testing timeliness, consistency, and sensitivity are all desired.

An electrochemical immunosensor using SARS-CoV-2 spike protein-nickel hydroxide nanoparticles bio-conjugate modified SPCE for ultrasensitive detection of SARS‐CoV‐2 antibodies

As a promising approach for serological tests, the present study aimed at designing a robust electrochemical biosensor for selective and quantitative analysis of SARS‐CoV‐2-specific viral antibodies. In our proposed strategy, recombinant SARS-CoV-2 spike protein antigen (spike protein) was used as a specific receptor to detect SARS‐CoV‐2-specific viral antibodies. In this sense, with a layer of nickel hydroxide nanoparticles (Ni(OH)2 NPs), the screen-printed carbon electrode (SPCE) surface was directly electrodeposited to ensure better loading of spike protein on the surface of SPCE. The differential pulse voltammetry (DPV) showed signals which were inversely proportional to the concentrations of the antibody (from 1 fg mL−1 L to 1 µg mL−1) via a specific and stable binding reaction. The assay was performed in 20 min with a low detection limit of 0.3 fg mL−1. This biodevice had high sensitivity and specificity as compared to non-specific antibodies. Moreover, it can be regarded as a highly sensitive immunological diagnostic method for SARS‐CoV‐2 antibody in which no labeling is required. The fabricated hand-held biodevice showed an average satisfactory recovery rate of ~99-103% for the determination of antibodies in real blood serum samples with the possibility of being widely used in individual serological qualitative monitoring. Also, the biodevice was tested using real patients and healthy people samples, where the results are already confirmed using the enzyme-linked immunosorbent assay (ELISA) procedure, and showed satisfactory results.

Echinacoside alleviates acetaminophen-induced liver injury by attenuating oxidative stress and inflammatory cytokines in mice.

This study evaluates the protective effect of Echinacoside on acute liver toxicity induced by acetaminophen in mice and the mechanism behind it. Echinacoside and N-Acetyl Cysteine were intragastrically administrated for 7 days, and acetaminophen was intraperitoneally injected into mice 1 h after the last treatment on day 7. At the end of the experimental period, histological examination, parameters for the level of oxidative damage, hepatic malondialdehyde, serum pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-6, and interleukin-1β), UDP-glucuronosyltransferases, and sulfotransferases changes were examined using enzyme-linked immunosorbent assay and standard biochemical procedures. The expression of cytochrome P450 2E1 protein was assessed by western blot, followed by in silico molecular docking. Acetaminophen treatment obviously increased the levels of ALT and AST, changed hepatic histopathology, promoted oxidative stress, decreased antioxidant enzyme activities, and elevated the pro-inflammatory cytokines. Echinacoside significantly attenuated Acetaminophen-induced liver damage in a dose-dependent manner, with the most effective dose at 100 mg/kg. The pretreatments of Echinacoside in different concentrations altered the Acetaminophen-induced hepatotoxicity levels by decreasing the level of liver enzymes, reducing the liver necrosis with vacuolization, decreasing the hepatic malondialdehyde formation, increasing hepatic antioxidants activities, suppressing the pro-inflammatory cytokines (Tumor Necrosis Factor, Interleukin-6 and Interleukin-1beta), inhibiting Nitric Oxide production, enhancing sulfotransferases and UDP-glucuronosyltransferases activities. Notably, the expression of cytochrome P450 2E1 was inhibited by Echinacoside in a dose-dependent manner and the binding energy was -214.3 MeV. Echinacoside showed a significant protective effect against Acetaminophen-induced hepatotoxicity through the inhibition of oxidative stress, the expression of pro-inflammatory cytokines and cytochrome P450 2E1 protein expression.

Trehalose and N-Acetyl Cysteine Alleviate Inflammatory Cytokine Production and Oxidative Stress in LPS-Stimulated Human Peripheral Blood Mononuclear Cells

ABSTRACT Background Evidence has shown that inflammation and oxidative stress are implicated in the development of a great number of human diseases. Trehalose possesses various biological effects including antioxidant and anti-inflammatory activities. However, there is little data on the effects of trehalose on human cells including peripheral blood mononuclear cells (PBMCs). Here, we aimed to investigate whether trehalose could attenuate oxidative stress and inflammation induced by lipopolysaccharides (LPS) in PBMCs. Methods The enzyme-linked immunosorbent assay (ELISA) and RT-PCR were used to assess the levels of inflammatory cytokines. To investigate the phosphorylation of c-Jun N-terminal kinase (JNK) and NF-κB, western blot analysis was utilized. Oxidant-antioxidant markers were assessed using ELISA and colorimetric procedures. Results The results revealed that trehalose significantly mitigated the effect of LPS on the phosphorylation of JNK and NF-κB-P65 (p < .00). This mitigation was associated with significantly reduced levels of inflammatory cytokines IL-6, TNF-α, and IL-1β and increased levels of anti-inflammatory cytokine IL-10 (P < .05). The antioxidant N-acetyl cysteine (NAC) also showed similar effects on JNK and NF-κB-P65 phosphorylation and inflammatory cytokines (p < .00). Furthermore, trehalose alleviated oxidative stress in LPS-stimulated PBMCs as it reversed the altered levels of malondialdehyde and total thiols (p ≤ .05) and restored the activity of antioxidant enzymes glutathione peroxidase and manganese superoxide dismutase (p < .001). Conclusion The results of this study indicated that trehalose prevented inflammation and oxidative stress in the LPS-stimulated PBMCs, providing evidence for the benefits of trehalose as a potential therapeutic agent in inflammatory conditions. Abbreviations LPS: Lipopolysaccharide; NAC: N-Acetyl cysteine; ROS: Reactive oxygen species; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-alpha; SOD: Superoxide dismutase; GPx: Glutathione peroxidase; MDA: Malondialdehyde; MAPK: Mitogen-activated protein kinases; JNK: c-Jun N-terminal kinase; NF-κB: Nuclear factor kappa-light-chain-enhancer of activated B cells.

Infectious serology, how to test large series without pooling samples

Pooling samples for serological testing was used first during the second world war. It was described later as a cost-effective technique permitting large screening of populations, especially for new infectious diseases. However, the dilution effect is responsible for decreasing sensitivity, limiting its use in practice, especially in blood banking. In this paper, we describe a modification of the classic enzyme-linked immunosorbent assay (ELISA) procedure, which permits the test of indefinite samples using just one well. Specimens are tested pure one by one without any dilution, so sensitivity remains unchanged. This new procedure is time-consuming but can be considered as a revolution in qualitative ELISA testing.

Acute Traumatic Brain Injury-Induced Neuroinflammatory Response and Neurovascular Disorders in the Brain.

Acute traumatic brain injury (TBI) leads to neuroinflammation, neurodegeneration, cognitive decline, psychological disorders, increased blood-brain barrier (BBB) permeability, and microvascular damage in the brain. Inflammatory mediators secreted from activated glial cells, neurons, and mast cells are implicated in the pathogenesis of TBI through secondary brain damage. Abnormalities or damage to the neurovascular unit is the indication of secondary injuries in the brain after TBI. However, the precise mechanisms of molecular and ultrastructural neurovascular alterations involved in the pathogenesis of acute TBI are not yet clearly understood. Moreover, currently, there are no precision-targeted effective treatment options to prevent the sequelae of TBI. In this study, mice were subjected to closed head weight-drop-induced acute TBI and evaluated neuroinflammatory and neurovascular alterations in the brain by immunofluorescence staining or quantitation by enzyme-linked immunosorbent assay (ELISA) procedure. Mast cell stabilizer drug cromolyn was administered to inhibit the neuroinflammatory response of TBI. Results indicate decreased level of pericyte marker platelet-derived growth factor receptor-beta (PDGFR-β) and BBB-associated tight junction proteins junctional adhesion molecule-A (JAM-A) and zonula occludens-1 (ZO-1) in the brains 7 days after weight-drop-induced acute TBI as compared with the brains from sham control mice indicating acute TBI-associated BBB/tight junction protein disruption. Further, the administration of cromolyn drug significantly inhibited acute TBI-associated decrease of PDGFR-β, JAM-A, and ZO-1 in the brain. These findings suggest that acute TBI causes BBB/tight junction damage and that cromolyn administration could protect this acute TBI-induced brain damage as well as its long-time consequences.

Plasma acrolein level in rheumatoid arthritis increases independently of the disease characteristics

Objective This study aimed to clarify whether plasma acrolein level actually increases in rheumatoid arthritis (RA) patients, and to elucidate whether any relationship exists between the levels and the RA background variables. Methods Plasma levels of protein-conjugated acrolein (PC-Acro) in 84 patients (RA group) and 298 normal individuals (Control group) were measured by enzyme-linked immunosorbent assay procedures. The data were statistically analyzed with Wilcoxon rank-sum test, multiple logistic regression analyses and Spearman’s rank correlation coefficient. Results The RA group showed significantly higher PC-Acro levels than the Control group (median [interquartile range]: 80.5 [63.2–105.2] and 65.9 [58.9–78.1] nmol/ml, respectively). Of background factors giving influence to PC-Acro level in the combination of the two groups, ‘diagnosis of RA positive’ indicated strong correlation to high PC-Acro level (odds ratio: 2.96; 95% confidence interval: 1.54–5.71). These increases of PC-Acro in the RA patients did not correlate to their disease duration and/or inflammatory variables: PC-Acro level could elevate even in early RA patients showing negative inflammatory findings. Conclusion Plasma levels of PC-Acro increased with RA, but the levels did not correlate with RA background variables. This report provides the basis for further studies of early diagnosis of RA as well as its pathogenesis.

Metagenomic Analysis of Plant Viruses Associated With Papaya Ringspot Disease in Carica papaya L. in Kenya.

Carica papaya L. is an important fruit crop grown by small- and large-scale farmers in Kenya for local and export markets. However, its production is constrained by papaya ringspot disease (PRSD). The disease is believed to be caused by papaya ringspot virus (PRSV). Previous attempts to detect PRSV in papaya plants showing PRSD symptoms, using enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase-polymerase chain reaction (RT-PCR) procedures with primers specific to PRSV, have not yielded conclusive results. Therefore, the nature of viruses responsible for PRSD was elucidated in papaya leaves collected from 22 counties through Illumina MiSeq next-generation sequencing (NGS) and validated by RT-PCR and Sanger sequencing. Viruses were detected in 38 out of the 48 leaf samples sequenced. Sequence analysis revealed the presence of four viruses: a Potyvirus named Moroccan watermelon mosaic virus (MWMV) and three viruses belonging to the genus Carlavirus. The Carlaviruses include cowpea mild mottle virus (CpMMV) and two putative Carlaviruses—closely related but distinct from cucumber vein-clearing virus (CuVCV) with amino acid and nucleotide sequence identities of 75.7–78.1 and 63.6–67.6%, respectively, in the coat protein genes. In reference to typical symptoms observed in the infected plants, the two putative Carlaviruses were named papaya mottle-associated virus (PaMV) and papaya mild mottle-associated virus (PaMMV). Surprisingly, and in contrast to previous studies conducted in other parts of world, PRSV was not detected. The majority of the viruses were detected as single viral infections, while a few were found to be infecting alongside another virus (for example, MWMV and PaMV). Furthermore, the NGS and RT-PCR analysis identified MWMV as being strongly associated with ringspot symptoms in infected papaya fruits. This study has provided the first complete genome sequences of these viruses isolated from papaya in Kenya, together with primers for their detection—thus proving to be an important step towards the design of long-term, sustainable disease management strategies.

A LEGO inspired fiber probe analytical platform for early diagnosis of Dengue fever.

Based on the concept of LEGO toys, a fiber probe analytical platform (FPAP) was developed as a powerful diagnostic tool offering higher sensitivity in detection of infectious agents compared to established methods. Using the form and the function of LEGO toys, this protocol describes a fiber-based, 96-well plate, which suspends a new class of chemically-designed, electrospun fibers within the assay. This clamping strategy allows both sides of the developed fiber mats to interact with biomolecules within the assay thus benefiting from the tailored chemical and physical properties of these fiber-based bioreceptors in attracting the biomolecules to the surface. The fabrication method of FPAP involves one-step electrospinning of the chemically designed fibers, 3D printing of the LEGO-like probing segments, and assembly of the device followed by ELISA procedure. FPAP follows the same principles of operation as that of a conventional enzyme linked immunosorbent assay (ELISA), therefore, it can be run by lab technicians, expert in ELISA. FPAP was used for early diagnosis of Dengue fever and provided an 8-fold higher sensitivity while the limit of detection (LOD) was recorded to be in femto-gram per milliliter range which is significantly low when compared to other existing techniques or conventional assay. This platform allows different types of paper/fiber bio-receptive platforms to be incorporated within the design that promises simultaneous recognition of multiple infectious agents.

A lab in a bento box: an autonomous centrifugal microfluidic system for an enzyme-linked immunosorbent assay.

In this paper, we report on the demonstration of a portable immunoassay system consisting of a small centrifugal microfluidic device driver (bento box) and a centrifugal microfluidic device made of polypropylene and fabricated by injection molding. The bento box consists of a cheap DC motor and an Arduino microcontroller. It has a simple structure and is the size of a bento box, that is, 150 × 150 × 100 (W × D × H) mm3. The developed device can automatically execute an enzyme-linked immunosorbent assay (ELISA) process under a steady rotating condition because it was designed based on the principle of CLOCK, which we previously presented. Here, we first executed an ELISA using a system consisting of the bento box and a device made of polydimethylsiloxane (PDMS) and compared it with a servo-controlled device driver. It was confirmed that the results of the bento box were consistent with those of the servo-controlled device driver. The limit of detection (LOD) using the bento box was 0.759 ng ml-1. Therefore, the controllability of the bento box was demonstrated. Next, we evaluated the injection-molded device through multi-step fluid control. We confirmed, through real-time observation of the device, that accurate flow control in the designed ELISA procedure was executed. Lastly, ELISA was employed for the measurements of mouse IgG using the system consisting of the bento box and the polypropylene device. The system performed all fluidic controls within 12 min; we confirmed the specificity of the system, and the LOD was 0.320 ng ml-1.