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Background: Platelet-rich fibrin (PRF) is used to prepare "sticky bone" by combining it with bone graft material. The present study investigated the ability of different bone grafts to absorb growth factors from the PRF and release them over time. Materials and Methods: Human blood was collected from 10 healthy volunteers for liquid PRF preparation. Bovine bone, allograft (mineralized and demineralized), and synthetic bone were each mixed with the PRF to prepare a sticky bone. All sticky bone samples were incubated for up to 4 days. The absorption and release pattern kinetics of two selective growth factors within the PRF--platelet-derived growth factor (PDGF) and bone morphogenetic protein-2 (BMP-2)--were quantified with immunofluorescence staining and enzyme-linked immunoassay (ELISA) testing. Results: All bone graft materials adsorbed the examined growth factors from the PRF. ß-TCP showed the highest adsorption levels, followed by the xenograft, and the allografts showed the lowest adsorption levels. Furthermore, PDGF showed a fast-release pattern from the grafts, whereas BMP-2 was released at a later stage. Similar to the adsorption pattern, the ß-TCP and xenograft were better able to sustain the release of the PRF growth factors from the graft than the allografts. Conclusions: The adsorption of PDGF and BMP-2 differ between graft materials, with superior results for ß-TCP, followed by xenograft, then allograft materials. [ABSTRACT FROM AUTHOR]

Healthcare facilities produce millions of tons of waste annually, with a significant portion consisting of diagnostic plasticware. Here, we introduce a new detection platform that completely replaces traditional assay plates with a piece of membrane, offering a much greener and more sustainable alternative. The membrane, integrated within the portable vortex fluidic device (P-VFD), enables rapid detection of a clinically relevant protein biomarker, urinary p75ECD. This biomarker is utilized to evaluate the prognosis, disease severity, and progression of amyotrophic lateral sclerosis (ALS). This assay has a limit-of-detection (LOD) of 4.03 pg, which is comparable to the plate-based assay (2.24 pg) and has been optimized through a full factorial design of experiments (DOE). P-VFD has great potential in quantifying p75ECD in human biofluids and can significantly reduce the assay time to 5 min compared to the current plate-based p75ECD ELISA assay (3 days), with at least a 4.4-fold reduction in the usage of the detection antibody.

This study aimed to evaluate and compare the performance of three anti-S and one anti-N assays that were available to the project in detecting antibody levels after three commonly used SARS-CoV-2 vaccines (Pfizer, Moderna, and Johnson & Johnson). It also aimed to assess the association of age, sex, race, ethnicity, vaccine timing, and vaccine side effects on antibody levels in a cohort of 827 individuals. In September 2021, 698 vaccinated individuals donated blood samples as part of the Association for Diagnostics & Laboratory Medicine (ADLM) COVID-19 Immunity Study. These individuals also participated in a comprehensive survey covering demographic information, vaccination status, and associated side effects. Additionally, 305 age- and gender-matched samples were obtained from the ADLM 2015 sample bank as pre-COVID-19-negative samples. All these samples underwent antibody level analysis using three anti-S assays, namely Beckman Access SARS-CoV-2 IgG (Beckman assay), Ortho Clinical Diagnostics VITROS Anti-SARS-CoV-2 IgG (Ortho assay), Siemens ADVIA Centaur SARS-CoV-2 IgG (Siemens assay), and one anti-N antibody assay: Bio-Rad Platelia SARS-CoV-2 Total Ab assay (BioRad assay). A total of 827 samples (580 COVID-19 samples and 247 pre-COVID-19 samples) received results for all four assays and underwent further analysis. Beckman, Ortho, and Siemens anti-S assays showed an overall sensitivity of 99.5%, 97.6%, and 96.9%, and specificity of 90%, 100%, and 99.6%, respectively. All three assays indicated 100% sensitivity for individuals who received the Moderna vaccine and boosters, and over 99% sensitivity for the Pfizer vaccine. Sensitivities varied from 70.4% (Siemens), 81.5% (Ortho), and 96.3% (Beckman) for individuals who received the Johnson & Johnson vaccine. BioRad anti-N assays demonstrated 46.2% sensitivity and 99.25% specificity based on results from individuals with self-reported infection. The highest median anti-S antibody levels were measured in individuals who received the Moderna vaccine, followed by Pfizer and then Johnson & Johnson vaccines. Higher anti-S antibody levels were significantly associated with younger age and closer proximity to the last vaccine dose but were not associated with gender, race, or ethnicity. Participants with higher anti-S levels experienced significantly more side effects as well as more severe side effects (e.g., muscle pain, chills, fever, and moderate limitations) (p < 0.05). Anti-N antibody levels only indicated a significant correlation with headache. This study indicated performance variations among different anti-S assays, both among themselves and when analyzing individuals with different SARS-CoV-2 vaccines. Caution should be exercised when conducting large-scale studies to ensure that the same platform and/or assays are used for the most effective interpretation of the data.

BACKGROUND: Lipoprotein(a) is a risk factor for cardiovascular events and modifies the benefit of PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitors. Lipoprotein(a) concentration can be measured with immunoassays reporting mass or molar concentration or a reference measurement system using mass spectrometry. Whether the relationships between lipoprotein(a) concentrations and cardiovascular events in a high-risk cohort differ across lipoprotein(a) methods is unknown. We compared the prognostic and predictive value of these types of lipoprotein(a) tests for major adverse cardiovascular events (MACE). METHODS: The ODYSSEY OUTCOMES trial (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) compared the PCSK9 inhibitor alirocumab with placebo in patients with recent acute coronary syndrome. We compared risk of a MACE in the placebo group and MACE risk reduction with alirocumab according to baseline lipoprotein(a) concentration measured by Siemens N-latex nephelometric immunoassay (IA-mass; mg/dL), Roche Tina-Quant turbidimetric immunoassay (IA-molar; nmol/L), and a noncommercial mass spectrometry-based test (MS; nmol/L). Lipoprotein(a) values were transformed into percentiles for comparative modeling. Natural cubic splines estimated continuous relationships between baseline lipoprotein(a) and outcomes in each treatment group. Event rates were also determined across baseline lipoprotein(a) quartiles defined by each assay. RESULTS: Among 11 970 trial participants with results from all 3 tests, baseline median (Q1, Q3) lipoprotein(a) concentrations were 21.8 (6.9, 60.0) mg/dL, 45.0 (13.2, 153.8) nmol/L, and 42.2 (14.3, 143.1) nmol/L for IA-mass, IA-molar, and MS, respectively. The strongest correlation was between IA-molar and MS (r=0.990), with nominally weaker correlations between IA-mass and MS (r=0.967) and IA-mass and IA-molar (r=0.972). Relationships of lipoprotein(a) with MACE risk in the placebo group were nearly identical with each test, with estimated cumulative incidences differing by ≤0.4% across lipoprotein(a) percentiles, and all were incrementally prognostic after accounting for low-density lipoprotein cholesterol levels (all spline P≤0.0003). Predicted alirocumab treatment effects were also nearly identical for each of the 3 tests, with estimated treatment hazard ratios differing by ≤0.07 between tests across percentiles and nominally less relative risk reduction by alirocumab at lower percentiles for all 3 tests. Absolute risk reduction with alirocumab increased with increasing lipoprotein(a) measured by each test, with significant linear trends across quartiles. CONCLUSIONS: In patients with recent acute coronary syndrome, 3 lipoprotein(a) tests were similarly prognostic for MACE in the placebo group and predictive of MACE reductions with alirocumab at the cohort level. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01663402.

Dye-encoded bead-based assays are widely used for diagnostics. Multiple bead populations are required for multiplexing and can be produced using different dye colors, labeling levels, or combinations of dye ratios. Ready-to-use multiplex bead populations restrict users to specific targets, are costly, or require specialized instrumentation. In-house methods produce few bead plexes or require many fine-tuning steps. To expand bead encoding strategies, we present a simple, safe, and cost-effective bench-top system for generating bead populations using photobleaching. By photobleaching commercially available dye-encoded magnetic beads for different durations, we produce three times as many differentiable bead populations on flow cytometry from a single dye color. Our photobleaching system uses a high-power LED module connected to a light concentrator and a heat sink. The beads are photobleached in solution homogeneously by constant mixing. We demonstrate this photobleaching method can be utilized for cross-testing antibodies, which is the first step in developing immunoassays. The assay uses multiple photobleached encoded beads conjugated with capture antibodies to test many binding pairs simultaneously. To further expand the number of antibodies that can be tested at once, several antibodies were conjugated to the same bead, forming a pooled assay. Our assay predicts the performance of antibody pairs used in ultrasensitive Simoa assays, narrowing the number of cross-tested pairs that need to be tested by at least two-thirds and, therefore, providing a rapid alternative for an initial antibody pair screening. The photobleaching system can be utilized for other applications, such as multiplexing, and for photobleaching other particles in solution. [ABSTRACT FROM AUTHOR]

In kidney transplant recipients, urine CXCL9 and CXCL10 (uCXCL9/10) chemokines have reached a sufficiently high level of evidence to be recommended by the European Society of Organ Transplantation for the monitoring of immune quiescence. To assess the risk of acute rejection (AR), the advantage of uCXCL9/10 is their cost-effectiveness and their high diagnostic performance. Here, we evaluated the feasibility of a next-generation immunoassay for quantifying uCXCL9/10 levels. It demonstrated high efficiency with minimal workflow and a 90-min time to result. Preanalytical studies indicated stability of uCXCL9/10 levels and analytical studies confirmed excellent linearity and precision. In a cohort of 1048 samples collected at biopsy, the results correlated significantly with ELISA quantification and were integrated into a previously validated 8-parameter urine chemokine model. The next generation immunoassay achieved an accuracy of 0.84 for AR diagnosis. This study validates this technology as a robust, locally available and unexpensive platform and marks a significant step towards the widespread implementation of uCXCL9/10, for immune quiescence monitoring. Therefore, we developed an open-access web application using uCXCL9/10 to calculate AR risk and improve clinical decision-making to perform biopsy, ushering in a new era in kidney transplantation, where personalized, data-driven care becomes the norm. [ABSTRACT FROM AUTHOR]

This article examines the use of high-sensitivity cardiac troponin (hs-cTn) assays to rule out non-ST elevation myocardial infarction (NSTEMI). Despite concerns about assay imprecision, studies have shown that the single sample rule out (SSRO) method is safe. The article provides data on the imprecision of hs-cTnT assays and calculates the probability of misclassification for different troponin values. The risk of misclassification is low, particularly when the initial troponin value exceeds 7 ng/L. An alternative SSRO threshold of 6 ng/L has also been found to be clinically safe. The article also discusses the misclassification issue with the Roche elecys e801 hs-cTnT assay, which had a low rate of misclassification, with less than 0.08% of results in the range of 6-7 ng/L being misclassified. The study concludes that despite the imprecision, the assay is precise enough to ensure that misclassifications are rarely clinically significant. [Extracted from the article]

Objective: Vitamin D deficiency is a common public health issue worldwide. The purpose of this study was to investigate the vitamin D status and its potential determinants in children residing in Sardinia (40°N), Italy. Methods: Children were enrolled over a 12-month period. Serum 25(OH)D was measured by an immunochemiluminescence assay. A questionnaire was used to gather information on other variables, including passive smoke exposure. Results: A total of 182 children (males: 51.7%; median age: 9 years) were included. Mean±standard deviation serum 25(OH)D was 25.2±8.3 ng/mL for the whole group. The majority (n=123, 67.6%) had vitamin D sufficient values >20 ng/mL, while 32.4% (n=59) had vitamin D insufficient/deficient values (≤20 ng/mL). Among the variables investigated, passive smoke exposure was significantly associated with insufficient 25(OH)D levels (p<0.0001). Conclusion: Our results confirm that hypovitaminosis D is common in Italian children. Furthermore, passive smoke exposure was identified as a significant risk factor for hypovitaminosis D. [ABSTRACT FROM AUTHOR]

Background: Pauci‐immune glomerulonephritis (GN) due to antineutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV) is a common cause of crescentic GN. Despite advances in treatment, rates of mortality and progression to end‐stage kidney disease remain high. Renal involvement is diagnosed by histological examination of kidney tissue. Serum ANCAs play a significant role in AAV; however, the value of serum ANCA quantification to predict renal involvement is not well‐established. Aim: We aimed to evaluate the diagnostic accuracy of serum ANCA titres in diagnosing AAV with renal involvement. Methods: We conducted a retrospective study of consecutive native kidney biopsies reported at our centre from 2016 to 2021. We included all adults who had both a kidney biopsy and ANCA serology. ANCA serology was tested using indirect immunofluorescence with reporting of titres. Antibodies to proteinase 3 and myeloperoxidase were measured using a chemiluminescent immunoassay. Results: Eight hundred and forty‐eight native kidney biopsies were reported during the study period. Five hundred and seven cases were included. The biopsy prevalence of pauci‐immune GN in paired samples was 41/507 (8.1%). Most of the cohort had haematuria (66.6%), proteinuria (93.4%) and/or acute kidney injury (65.0%). A positive ANCA at any titre demonstrated a sensitivity of 97.6% and a specificity of 71.2% for a diagnosis of pauci‐immune GN. The area under the curve for the receiver operator characteristic was 0.93 (95% confidence interval [CI]: 0.89–0.97). A cutoff ANCA titre of 1:160 provided the optimum balance between a sensitivity of 75.6% (95% CI: 59.7%–87.6%) and a specificity of 94.0% (95% CI: 91.6%–96.0%). Conclusions: ANCA titres are highly predictive of pauci‐immune GN in the appropriate context. While serum ANCA quantitation may not replace renal biopsy, reporting will assist in the decision to start treatment early for patients with organ or life‐threatening disease. [ABSTRACT FROM AUTHOR]

Objectives Myositis-specific and associated autoantibodies are important biomarkers in routine clinical use. We assessed local testing performance for myositis autoantibodies by comparing line immunoassay (LIA) to protein radio-immunoprecipitation and identifying clinical characteristics associated with each myositis autoantibody in the MyoCite cohort. Methods Serum samples from patients within the MyoCite cohort, a well-characterized retro-prospective dataset of adult and juvenile idiopathic inflammatory myopathy (IIM) patients in Lucknow, India (2017–2020), underwent LIA at Sanjay Gandhi Postgraduate Institute of Medical Science (SGPGIMS), Lucknow. Immunoprecipitation of 147 IIM patients' serum samples (125 adult-onset, 22 juvenile-onset) was conducted at the University of Bath, with researchers blind to LIA results. LIA performance was assessed against immunoprecipitation as the reference standard, measuring sensitivity, specificity and inter-rater agreement. Univariate and multivariate logistic regression determined clinical associations for specific myositis-specific autoantibodies. Results Immunoprecipitation identified myositis autoantibodies in 56.5% (n  = 83) of patient samples, with anti-Jo1 (n  = 16; 10.9%) as the most common, followed by anti-MDA5 (n  = 14, 9.5%). While LIA showed good agreement for anti-Jo1, anti-PL7 and anti-PL12 (Cohen's κ 0.79, 0.83 and 1, respectively), poor agreement was observed in other subgroups, notably anti-TIF1γ (Cohen's κ 0.21). Strongly positive samples, especially in myositis-specific autoantibodies, correlated more with immunoprecipitation results. Overall, 59 (40.1%) samples exhibited non-congruence on LIA and immunoprecipitation, and κ values for LIAs for anti-TIF1γ, anti-Ku, anti-PmScl, anti-Mi2 and anti-SAE ranged between 0.21 and 0.60. Conclusion While LIA reliably detected anti-Jo1, anti-PL7, anti-PL12, anti-MDA5 and anti-NXP-2, it also displayed false positives and negatives. Its effectiveness in detecting other autoantibodies, such as anti-TIF1γ, was poor. [ABSTRACT FROM AUTHOR]

When faced with increasing drug‐related deaths and decline in practicing forensic pathologists, the need to quickly identify toxicology‐related deaths is evident in order to appropriately triage cases and expedite turnaround times. Lateral flow immunoassays conducted pre‐autopsy offer quick urine drug screen (UDS) results in minutes and are used to inform the need for autopsy. Over 1000 medicolegal cases were reviewed to compare UDS results to laboratory enzyme‐linked immunosorbent assay (ELISA) blood results to evaluate how well autopsy UDS predicted laboratory findings. Mass spectral analysis was performed on ELISA‐positive specimens and these data were used to investigate UDS false‐negative (FN) results when possible. Five different UDS devices (STAT One Step Drug of Abuse dip card and cassette, Premiere Biotech multi‐drug and fentanyl dip cards and ATTEST 6‐acetylmorphine (6‐AM) dip card) were tested encompassing 11 drug classes: 6‐AM, amphetamine/methamphetamine, benzodiazepines, benzoylecgonine, fentanyl, methadone, opioids, phencyclidine, and delta‐9‐tetrahydrocannabinol. Sensitivity, specificity, efficiency, and positive and negative predictive values >80% indicated that UDS was useful for predicting cases involving benzoylecgonine, methadone, methamphetamine, and phencyclidine. UDS was unreliable in predicting amphetamine, benzodiazepines, fentanyl, and opiates‐related cases due to a high percentage of FN (up to 11.2%, 8.0%, 12.4%, and 5.5%, respectively) when compared to ELISA blood results. For the later analytes, sensitivities were as low as 57.5%, 60.0%, 72.2%, and 66.7%, respectively. Overall results support that UDS cannot replace laboratory testing. Because UDS is subject to false‐positive and FN results users must understand the limitations of using UDS for triage or decision‐making purposes. [ABSTRACT FROM AUTHOR]

Objective: Our objective was to evaluate the association of serum biomarkers with baseline psoriatic arthritis (PsA) disease activity, pharmacodynamic effects of deucravacitinib on biomarker levels, and the relationship between biomarkers and clinical responses to deucravacitinib. Methods: The phase 2 trial (ClinicalTrials.gov identifier: NCT03881059) randomly assigned 203 patients with PsA 1:1:1 to placebo, deucravacitinib at 6 mg once daily (QD), or deucravacitinib at 12 mg QD. Serum biomarkers associated with the interleukin 23 (IL‐23) pathway (IL‐17A, β‐defensin [BD‐2], and IL‐19), type I interferon pathway, inflammation, and collagen matrix turnover were measured by immunoassay. Clinical responses (≥75% improvement from baseline in the Psoriasis Area and Severity Index [PASI75] and ≥20% improvement from baseline in American College of Rheumatology criteria [ACR20] responses) were measured at week 16. Hematologic variables were also assessed. Results: IL‐17A, BD‐2, and IL‐19 had a modest association with PASI scores (r = 0.4, r = 0.56, and r = 0.5, respectively) at baseline. In deucravacitinib groups, IL‐17A, BD‐2, IL‐19, C‐X‐C motif ligand 9 (CXCL9), CXCL10, C‐reactive protein, matrix metalloproteinase 3, and collagen type 4 degradation marker levels were significantly reduced at week 16 versus baseline (P < 0.01); higher levels of IL‐23 pathway–associated biomarkers predicted higher PASI75 and ACR20 response rates in deucravacitinib‐treated patients. Significantly higher PASI75 response rates were seen in patients with high baseline IL‐17A (odds ratio 15.76) and BD‐2 levels (odds ratio 15.41) versus low baseline IL‐17A and BD‐2 levels. Changes in hematologic variables that are characteristic of JAK inhibition were not observed with deucravacitinib. Conclusion: Deucravacitinib significantly impacted biomarkers associated with Tyk2 signaling pathways of key inflammatory cytokines, including IL‐23 and type I interferon, and those related to collagen matrix turnover. These biomarkers may predict treatment responses to deucravacitinib. [ABSTRACT FROM AUTHOR]

Serological tests of non-treponemal and treponemal types are the most frequently used for syphilis diagnosis. Nontreponemal tests are used to monitor disease activity. Toluidine red unheated serum test (TRUST), as one of nontreponemal tests, is generally applicable to hospitals at different levels. However, accurate judgment of TRUST results is inseparable from an experienced and accurate operator. To reduce current shortcomings of manual TRUST method, we attempted to convert the manual TRUST test into automatic TRUST test, that is, to determine the degree of aggregation of toluidine red particles by detecting the absorbance value of serum after reaction with toluidine red particles. 50 μL of serum sample and 80 μL toluidine red particles were added to 96-well plate. Then, the 96-well plate was placed on a microplate reader at medium grade for 8 min to mix. Then, plasma reagin reacted with toluidine red particles and promoted the aggregation of toluidine red particles to form a large clot, which eventually caused a decrease in the absorbance at 540 nm. The results showed that the specificity of the automatic TRUST test was 100%, the sensitivity was 87%. And this method showed 93.5% correlation with manual TRUST test. The developed method is simple and involves less subjectivity in reading results, opening new avenues for syphilis diagnostic testing. Turbidimetric immunoassay can avoid the shortcomings of subjective interpretation, time-consuming and manual operation of manual TRUST method, and is more suitable for large-scale screening in health examination. [ABSTRACT FROM AUTHOR]

Context.--Pemphigus is an autoimmune blister disease that causes blisters on the skin and mucosal surfaces. Direct immunofluorescence (DIF) testing is critical for the clinical diagnosis of pemphigus. However, it is limited to fresh tissue specimens and fluorescence microscopy. Objective.--To assess the value of C3d immunohistochemistry (IHC) on paraffin-embedded skin tissue for the diagnosis of pemphigus by comparing C3d-IHC results to DIF and enzyme-linked immunosorbent assay testing in pemphigus and other blister-related skin diseases. Design.--C3d-IHC assays were retrospectively performed on paraffin-embedded skin tissue sections from 115 patients (63 with pemphigus and 52 controls). Both the case group and the control group underwent the same protocol, and cases with C3d position in the peripheral spinous layer were considered as positive samples. Results.--C3d-IHC and DIF testing had similar performance for pemphigus diagnosis, with a sensitivity of 71.0% (95% CI, 51.8%-85.1 %) and 77.4% (95% CI, 58.5%-89.7%), specificity of 96.4% (95% CI, 79.8%-99.8%) and 100% (95% CI, 85.0%-100%), positive predictive value of 95.7% (95% CI, 76.0%-99.8%) and 100% (95% CI, 82.8%-100%), and a negative predictive value of 75.0% (95% CI, 57.5%-87.3%) and 80.0% (95% CI, 62.5%-90.9%), respectively. Conclusions.--Our study indicated that C3d-IHC results for paraffin-fixed tissues were not significantly different from DIF results for the diagnosis of pemphigus. The C3d-IHC assay has the potential for routine diagnosis of pemphigus, especially in the absence of fresh-frozen tissue. [ABSTRACT FROM AUTHOR]

Copyright of Biomédica: Revista del Instituto Nacional de Salud is the property of Instituto Nacional de Salud of Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: This study evaluated the pharmacokinetic (PK) equivalence between BP02 (a proposed trastuzumab biosimilar) and the reference trastuzumab approved in the EU (EU-trastuzumab) and the US (US-trastuzumab). Methods: In this phase 1, double-blind, parallel-group trial, 111 healthy male volunteers were randomized 1:1:1 to receive a single 6-mg/kg intravenous infusion of BP02, EU-trastuzumab, or US-trastuzumab and were evaluated for 78 days. Serum drug concentration–time data were analyzed by non-compartmental methods. The PK similarity of BP02 to the two reference products, and between EU-trastuzumab and US-trastuzumab, was determined using the standard 80–125% bioequivalence criteria. Results: Baseline demographics for the 111 subjects with evaluable pharmacokinetics were similar across all treatment groups. PK profiles were similar for the three products. The 90% confidence intervals (CIs) for the ratios of area under the serum concentration–time curve (AUC) from the time of dosing to infinity (AUC0-inf), AUC from the time of dosing until the time of the last quantifiable concentration (AUC0-t), and peak serum concentration of trastuzumab (Cmax) were within 80% to 125% for all three pairwise comparisons. Adverse events (AEs) were similar across all arms, with treatment-related AEs reported by 73.0%, 73.0%, and 89.2% of the subjects in the BP02, EU-trastuzumab, and US-trastuzumab groups, respectively. The most common AEs were headache, infusion-related reactions, and upper-respiratory-tract infections. Four subjects—three in the US-trastuzumab group and one in the BP02 group—discontinued the study due to AEs. All post-dose samples except for two tested negative for anti-drug antibodies. Conclusion: This study demonstrates the PK similarity among BP02, EU-trastuzumab, and US-trastuzumab. The safety and immunogenicity profiles observed for the three products in this study are consistent with previous reports for trastuzumab. Trial Registration: ANZCTR number: ACTRN12621000573853. [ABSTRACT FROM AUTHOR]

Copyright of Gefaesschirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Anti‐immunocomplex (Anti‐IC) antibodies have been used in developing noncompetitive immunoassays for detecting small molecule analytics (haptens). These antibodies bind specifically to the primary antibody in complex with hapten. Although several anti‐IC antibody–based immunoassays have been developed, structural studies of these systems are very limited. In this study, we determined the crystal structures of anti‐testosterone Fab220 in complex with testosterone and the corresponding anti‐IC antibody FabB12. The structure of the ternary complex of testosterone, Fab220, and FabB12 was predicted using LightDock and AlphaFold. The ternary complex has a large (~ 1100 Å2) interface between antibodies. The A‐ring of the testosterone bound by Fab220 also participates in the binding of the anti‐IC antibody. The structural analysis was complemented by native mass spectrometry. The affinities for testosterone (TES) and three cross‐reactive steroids [dihydrotestosterone (DHT), androstenedione (A4), and dehydroepiandrosterone sulfate (DHEA‐S)] were measured, and ternary complex formation was studied. The results clearly show the ternary complex formation in the solution. Although DHT showed significant cross‐reactivity, A4 and DHEA‐S exhibited minor cross‐reactivity. [ABSTRACT FROM AUTHOR]

Within the past decade, single domain antibodies (sdAbs) have been recognized as unique affinity binding reagents that can be tailored for performance in a variety of immunoassay formats. Luminex MagPlex color-coded magnetic microspheres provide a high-throughput platform that enables multiplexed immunoassays. We developed a MagPlex bead-based assay for the detection of SARS-CoV-2, using sdAbs against SARS-CoV-2 nucleocapsid (N) protein in which we engineered the sdAb capture reagents to orient them on the beads. The oriented sdAbs provided an increase in sensitivity over randomly oriented sdAbs for samples of N diluted in buffer, which also translated into better detection of SARS-CoV-2 in clinical samples. We assessed the specificity of the assay by examining seasonal coronavirus clinical samples. In summary, we provide a proof-of-concept that a bead-based assay using sdAbs to detect SARS-CoV-2 is feasible and future research combining it with other sdAbcoated beads that can detect other viruses may provide a useful diagnostic tool. [ABSTRACT FROM AUTHOR]

Traditional chemiluminescence (CL) imaging immunoassays usually rely on natural enzymes as catalytic probes, which has hampered their extensive application due to the susceptibility to inactivation of natural enzymes. In response, a gold brocade coated CoFe Prussian blue analogue (CoFe PBA@Au brocade) with enhanced peroxidase-like activity was synthesized and utilized as a powerful label probe for constructing a highly sensitive CL imaging immunosensor targeting disease biomarkers with excellent performance. This research offers a universal strategy for enhancing the sensitivity of CL imaging immunoassays and further expands the application of PBA nanozymes. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this work was to assess dynamic cytokine profiles associated with bloodstream infection (BSI) caused by Klebsiella pneumoniae (Kpn) and investigate the clinical features associated with mortality. Methods: A total of 114 patients with positive BSI-Kpn and 12 sepsis individuals without blood positive bacteria culture were followed up. Cytokine profiles were analyzed by multiplex immunoassay on the first, third, seventh and fourteenth day after diagnosis. The test cytokines included arginase, interferon-gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, IL-4, IL-6, IL-10, IL-12 (p70), and IL-23. The minimum inhibitory concentration (MIC) of 24 antibiotics were tested for BSI-Kpn. Risk factors associated with the 30-day mortality and 120-day mortality were evaluated using logistic analyses and nomogram. Results: There were 55 out of 114 patients with BSI-Kpn were included. All isolates showed high susceptibility rate to novel avibactam combinations. The level of arginase was the highest in carbapenem-resistant Kpn (CRKP) patients. The AUCs of arginase, TNF-α and IL-4 reached 0.726, 0.495, and 0.549, respectively, whereas the AUC for the combination of these three cytokines was 0.805. Notably, 120-day mortality in patients with CRKP was higher than carbapenem-sensitive K. pneumoniae (CSKP). Furthermore, the long-term and high levels of IL-6 and IL-10 were associated with death. Conclusions: High expression of arginase is correlated with CRKP. In addition, BSI-CRKP could result in indolent clinic course but poor long-term prognosis. Continuous increase of IL-6 and IL-10 were associated with mortality. [ABSTRACT FROM AUTHOR]

Background: Regional evidence on the role of vitamin D in the prevention of COVID-19 and its sequalae remains inconclusive and sparse. Objective: This study aimed to determine the association of COVID-19 status and severity with vitamin D among adults in Colombo District, Sri Lanka. Methods: A sex-matched case–control study was conducted among 104 RT-PCR-confirmed COVID-19 patients recruited from two major hospitals designated as COVID-19 treating centres and 104 RT-PCR negative adults recruited from the catchment area of the two hospitals. Non-fasting blood samples obtained from cases upon hospital admission and from controls upon release from 14-day quarantine period were analysed for serum 25(OH)D using chemiluminescence assay. Serum level < 50.0 nmol/L was identified as vitamin D deficiency (VDD). Results: Cases were older while the controls had fewer persons with co-morbidities. Cases (median = 30.0; IQR = 21.2 nmol/L) had significantly lower 25(OH)D compared to controls (median = 35.9; IQR = 28.3 nmol/L) (p = 0.02), which persisted after adjustments (p = 0.026), along with Sinhalese ethnicity (p < 0.001). VDD was significantly more prevalent in cases (83.7% vs. 71.2%; crude odds ratio (OR) = 2.1; 95% CI 1.1, 4.1); but was not an independent predictor of COVID-19 status (adjusted OR = 1.9; 95% CI 0.6, 5.7). A lower 25(OH)D level was observed in moderate/severe cases (median = 28.0; IQR = 20.4 nmol/L) vs. mild (median = 39.8; IQR = 19.0 nmol/L), however, neither low serum concentrations nor deficiency showed an independent relationship with severity (p > 0.05). Diabetes was the sole predictor of COVID-19 severity (p = 0.022). Conclusions: Vitamin D has potential as a primary preventive strategy in preventing COVID-19 like infections, but not as a secondary preventive strategy to reduce its severity. [ABSTRACT FROM AUTHOR]

Background/aims: Autoimmune hepatitis (AIH) is characterized by the presence of auto-antibodies and high blood immunoglobulin G (IgG) levels. In this study, the line immunoassay (LIA) was designed to assess various autoantibodies. Methods: In total, 1371 patients who underwent autoimmune liver disease antibody testing between July 2019 and November 2022 were enrolled. Autoantibodies including antinuclear antibody (ANA) and anti-mitochondrial antibody (AMA) were tested, and clinical data were collected. Statistical analyses were performed by categorizing the data based on diagnosis and IgG quantification separately. A scoring system was applied to identify individuals with AIH. Patients were also classified into the AIH and non-AIH groups. Results: The positivity rate for ANA was 80.2% in the AIH group. The IgG-high group had a high likelihood of the presence of detectable autoantibodies, with anti-Ro-52 being the most frequently detected antibody using LIA. The "Consider AIH" and "AMA" groups had 3–4 times more patients in the IgG-high group than in the "Not Considered" group. Conclusions: Among autoantibodies, the prevalence of ANA was the highest. As per LIA results, anti-Ro-52 was the most prevalent. AIH cannot be diagnosed based on IgG levels alone and must be distinguished via autoantibody testing. Therefore, extensive testing, including autoantibodies, IgG, ANA, and liver enzyme levels, will help accurately diagnose AIH. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Lab on a Chip," published by the Royal Society of Chemistry. It includes a range of papers on topics such as microfluidics, nanotechnology, and biomedical research. Some of the specific papers mentioned include a programmable and automated optical electrowetting-on-dielectric (oEWOD) driven platform for single cell assay operations, an on-chip phytofluidic device for studying nutrient flow in plant roots, and optimized microfluidic formulation for improved lipid nanoparticle mediated genome editing. The journal covers a variety of scientific disciplines and offers valuable research for those interested in these fields. [Extracted from the article]

The extraction of targets from biological samples for immunoassays using organic solvents, such as methanol, is often necessary. However, high concentrations of organic solvents in extracts invariably lead to instability of the employed antibody, resulting in poor performance of the immunoassay. Evaluating the tolerance ability and exploring the molecular mechanisms of antibody tolerance in organic solvents are essential for the development of robust immunoassays. In this work, 25 monoclonal antibodies and methanol are utilized as models to address these questions. A novel protocol is initially established to precisely and rapidly determine antibody tolerance in methanol, identifying two distinct methanol effect patterns. Through a detailed investigation of the structural basis, a novel hypothesis regarding methanol effect patterns is proposed, termed "folding‐aggregation," which is subsequently validated through molecular dynamics simulations. Furthermore, the investigation of sequence basis reveals significant differences in residue types within the complementarity‐determining regions and ligand‐binding residues, distinguishing the two antibody methanol effect patterns. Moreover, the methanol effect patterns of the antibodies are defined by germline antibodies. This work represents the first exploration of antibody methanol effect patterns and associated molecular mechanisms, with potential implications for the discovery and engineering of tolerant antibodies for the development of robust immunoassays. [ABSTRACT FROM AUTHOR]

Here we report on the use of nonaqueous synthesis programming of gold nanoparticles (NPs) and the antibiotic metronidazole using reconfigurable paper comprising an asynchronous modular paperfluidic linear instrument-free (Ampli) chemical plug and play construction set. Liquid fractions and reactions are replaced with paperfluidic membranes on blocks that can be snapped together and disconnected for real time design of experiments. Reagents are embedded into the paper membranes of each block, and reactions are synthesized by snapping together blocks and adding solution, which runs through the blocks in a sequence. Reaction products were characterized by different spectroscopic techniques (Raman spectroscopy, optical absorption spectroscopy, and dynamic light scattering). The resulting products were extracted to form functional NPs used in diagnostic immunoassays, and metronizadole was functional in an antibacterial disk diffusion assay. We investigated how to map off-the-shelf reactions onto individual Ampli blocks and how to successfully generate and extract these products. The paper-based synthesis was faster, significantly more affordable, and lighter than traditional methods, with important implications for local and distributed manufacturing. [ABSTRACT FROM AUTHOR]

Signal transducers are crucial in bioassay platforms for converting target detection into recordable signals. Commonly used color development for immunoassays involves enzymes and colorimetric substrates. However, due to cost and environmental issues, practical point‐of‐care testing requires alternative signal transducers. Growth‐induced extinction (absorption and scattering) of gold nanoclusters (AuNCs) is proposed as a novel approach for quantitative immunoassays. AuNCs devoid of localized surface plasmon resonance (LSPR) are used as seeds for growth reactions. Through reactions with a growth solution comprised of gold precursor and mild reductant, AuNCs of varying concentrations underwent controlled growth, resulting in nanoparticles of different sizes exhibiting distinct LSPR‐mediated extinction bands. Notably, the seed concentration exhibited a robust correlation with the resulting extinction of the grown particles on a small scale of 110 µL for a 96‐well microplate platform. To demonstrate this signal transduction mechanism, immunosorbent assays are performed using the conjugates of AuNC and detection antibody. The sandwich‐type assay successfully quantified a model antigen, human immunoglobulin G (hIgG), by monitoring LSPR wavelength and absorbance. This assay demonstrated a working range of 0.001–1 µg mL−1 and limit of detection of 1.19 ng mL−1. Signal transducers using the growth of AuNCs offer new alternative candidates for immunoassay platforms. [ABSTRACT FROM AUTHOR]

Parietal cell autoantibodies (PCAs), which recognize the enzyme H+/K+-ATPase as a target, are considered to be a diagnostic marker of autoimmune gastritis and pernicious anemia; these conditions are characterized by the presence of corpus atrophic gastritis. Circulating PCAs can be detected using several analytical methods that are commonly available in the clinical laboratory. Traditionally, indirect immunofluorescence (IIF) on rodent or primate stomach tissue is used as a screening test for the detection of PCAs. However, IIF suffers from a high inter-observer variability and lacks standardization. In addition, like immunoblotting, results are expressed only in a qualitative or semi-quantitative manner. Based on the few available studies that are reviewed herein, quantitative enzyme-linked immunosorbent assays (ELISAs) and fluorescence enzyme immunoassays (FEIAs) using purified H+/K+-ATPase perform better than IIF in the detection of PCAs, displaying higher sensitivity and utility in monitoring the disease. In light of their higher diagnostic accuracy, these solid-phase methods should be preferred to IIF in the screening of autoimmune atrophic gastritis. The use of methods to detect antibodies versus a specific subunit of H+/K+-ATPase (α or β) is currently confined to the world of research. Further investigation is required to define the clinical utility of H+/K+-ATPase subunit detection. [ABSTRACT FROM AUTHOR]

Introduction: Oligomeric alpha-synuclein in red blood cells (RBC-o-α-Syn) has been shown to be increased in patients with Parkinson's disease (PD). However, factors that affect RBC-o-α-Syn levels remain to be elucidated. The aim of this study is to analyze the correlations between RBC-o-α-Syn levels and the age, sex and different clinical variables of patients with PD. Methods: 167 patients with PD and 119 healthy controls (HC) were enrolled in this study. The patients with PD were diagnosed based on the MDS clinical diagnostic criteria for PD. All participants were evaluated for their clinical characteristics. Western blot analysis was used to examine the molecular sizes of RBC-o-α-Syn. A newly established chemiluminescent immunoassay was used to measure RBC-o-α-Syn levels. Results: Higher RBC-o-α-Syn levels were detected in PD patients than in HC subjects. The receiver operating characteristic (ROC) curve indicated that a cut off value of 55.29 ng/mg discriminated well between PD patients and HC subjects, with a sensitivity of 67.66% (95% CI: 60.24-74.29%), a specificity of 88.24% (95% CI: 81.22-92.86%), and an area under the curve (AUC) of 0.857. The levels of RBC-o-α-Syn were higher in female than male patients (p = 0.033). For different subtypes, the levels of RBC-o-α-Syn were higher in the MIX subtype than the tremor-dominant (TD) PD. In addition, the levels of RBC-o-α-Syn were higher in patients with than without cognitive impairment (p = 0.016), and negatively correlated with Mini-Mental State Examination (MMSE) scores (r = -0.156, p = 0.044). Conclusion: Our study demonstrates that RBC-o-α-Syn levels in patients with PD are higher than those in HC subjects and affected by the sex and the severity of cognitive impairment. [ABSTRACT FROM AUTHOR]

Background: To assess the association between various systemic lupus erythematosus (SLE) disease manifestations, SLE disease activity index 2000 (SLEDAI-2K), systemic lupus international collaborating clinics/American College of Rheumatology Damage Index (SLICC/ACR- SDI) and serum levels of Slit2 in SLE patients. Results: The mean age of SLE patients was 31.12 ± 8.68 years while the age at onset was 26.05 ± 7.60 years. Female: male was 9 vs 1. The mean serum levels of Slit2 in SLE patients were significantly higher than the controls (0.55 ± 0.25 vs 0.42 ± 0.15) (P = 0.013). There was no significant difference in Slit2 levels between patients with active vs inactive SLE (P = 0.353) or between patients with and without lupus nephritis (P = 0.900). An insignificant difference in Slit2 levels was found among SLE patients using SDI (P = 0.982). No significant correlations were observed between the serum Slit2 and SLE patients' demographics, laboratory data, SLEDAI-2K, and SDI except for a positive correlation with platelets and a negative correlation with serum albumin. ROC curve analysis showed that at a cutoff value of 0.44, the area under the curve was 0.677 (95% CI 0.538–0.816, P = 0.013) with a sensitivity of 74%, specificity of 56%, and accuracy of 68%. Conclusion: While we observed elevated serum Slit2 levels in SLE patients, there was no significant correlation observed between serum Slit2 levels and SLE clinical manifestations, disease activity, or damage index. Trial registration: NCT05105217. Registered 3 November 2021 [ABSTRACT FROM AUTHOR]

Although HPV vaccines are highly efficacious, a notable proportion of quadrivalent vaccinees are HPV18 seronegative post-vaccination. We have investigated this findings' validity by comparing vaccine-induced antibody responses using two different immunoassays. 6558 16–17-year-old females participated in the FUTURE II (NCT00092534) and PATRICIA (NCT00122681) trials in 2002–2004. Both the quadrivalent and bivalent vaccine recipients (QVR and BVR) received three doses. Twelve-year follow-up for 648 vaccinees was conducted by the Finnish Maternity Cohort. The presence of neutralising and binding HPV antibodies was analysed via HPV pseudovirion-based neutralisation and pseudovirion-binding assays. Four percent and 14.3% of the QVRs were seronegative for neutralising and binding antibodies to HPV16 and HPV18, respectively. No BVRs were HPV16/18 seronegative post-vaccination. The antibody titres were strongly correlated between the assays, Pearson's correlation coefficient, r[HPV16] = 0.92 and 0.85, and r[HPV18] = 0.91 and 0.86 among the QVRs and BVRs respectively. Fourteen percent of QVRs lacked detectable HPV18 antibodies in long-term follow-up. [ABSTRACT FROM AUTHOR]

Immunoassay methods typically involve the use of antibodies, which are either labeled with an enzyme to generate a detectable product or directly tagged with a radioactive or fluorescent substrate. One approach to enhance the specificity of immuno-detection methods is by employing a combination of different antibodies, such as primary and secondary. However, relying solely on one antibody targeting another may not offer the highest level of precision for improving immunoassay specificity; A novel strategy for enhancing the specificity of immunoassay techniques involves directly targeting different epitopes of an antigen. This approach entails utilizing sequential chain reactions facilitated by distinct enzymes bound to various antibodies, each directed at specific epitopes on the antigen. Such an innovative method holds promise for advancing the specificity of immunoassay methods. [ABSTRACT FROM AUTHOR]

Introduction: Programmed Death-Ligand 1 is a well-known immune checkpoint molecule. Recent studies evaluated its expression in different canine cancer types through different laboratory techniques. The present study aims to evaluate the surface membrane protein expression (mPD-L1) by means of flow cytometry (FC) in different canine lymphoma immunophenotypes. Furthermore, in a subset of cases, mRNA and plasmatic soluble protein (sPD-L1) have been assessed in the same patient, and correlations among results from the three analyses investigated. Methods: Samples obtained for diagnostic purpose from untreated dogs with a confirmed lymphoma immunophenotype were included: surface protein was assessed via FC and quantified with median fluorescence index ratio (MFI ratio), gene expression was evaluated by real time quantitative polymerase chain reaction (RT-qPCR) and plasmatic concentration of soluble protein (sPD-L1) measured with ELISA. Statistical analyses were performed to investigate any difference among FC immunophenotypes, updated Kiel cytological classes, and in the presence of blood infiltration. Results: Considering FC, most B-cell lymphomas (BCL) were positive, with higher MFI ratios than other subtypes (81%, median MFI ratio among positive samples = 1.50, IQR 1.21-2.03, range 1.01-3.47). Aggressive T-cell lymphomas had a lower percentage of positive samples (56%) and showed low expression (median MFI ratio in positive samples = 1.14, IQR 1.07-1.32, range 1.02-2.19), while T-zone lymphomas (TZL) were frequently positive (80%) but with low expression (median MFI ratio in positive samples = 1.19, IQR 1.03-1.46, range 1.02-6.03). Cellular transcript and sPD-L1 were detected in all samples, without differences among immunophenotypes. No correlation between results from different techniques was detected, but sPD-L1 resulted significantly increased in FC-negative lymphomas (p = 0.023). Discussion: PD-L1 molecule is involved in canine lymphoma pathogenesis, with differences among immunophenotypes detected by FC. Specifically, BCL have the highest expression and aggressive T-cell lymphomas the lowest, whereas TZL need further investigations. [ABSTRACT FROM AUTHOR]

Background: Consistent evidence shows that magnesium (Mg) intake is associated with lower blood pressure (BP), and that lower BP is associated with improved cerebral health. However, recent findings indicate that the positive effect of dietary Mg intake on cerebral health is not mediated by a decrease in BP. As Mg's anti-inflammatory action is a plausible alternative mechanism, the objective of this study was to investigate the associations between Mg intake and inflammation to determine whether it mediates any neuroprotective effect. Methods: Participants from the UK Biobank (n = 5775, aged 40–73 years, 54.7% female) were assessed for dietary magnesium using an online food questionnaire, brain and white matter lesion (WML) volumes were segmented with FreeSurfer software, and inflammation markers including high-sensitivity C-reactive protein (hs-CRP), leukocyte, erythrocyte count, and Glycoprotein acetylation (GlycA) were measured using specific laboratory techniques such as immunoturbidimetry, automated cell counting, and nuclear magnetic resonance. Hierarchical linear regression models were performed to investigate the association between dietary Mg, and inflammatory markers and between dietary Mg, brain and WMLs volumes. Mediation analysis was performed to test a possible mediation role of inflammation on the association between dietary Mg and brain and WMLs volumes. Results: Higher dietary Mg intake was associated with lower inflammation: hs-CRP level (− 0.0497%; 95% confidence interval [CI] − 0.0497%, − 0.0199%) leukocytes count (− 0.0015%; 95%CI − 0.00151%, − 0.0011%), and GlycA (− 0.0519%; 95%CI − 0.1298%, − 0.0129%). Moreover, higher dietary Mg intake was associated with larger grey matter volume (0.010%; 95%CI 0.004%, 0.017%), white matter volume (0.012%; 95%CI 0.003, 0.022) and right hippocampal volume (0.002%; 95%CI 0.0007, –0.0025%). Lower hs-CRP levels mediated the positive association between higher dietary Mg intake and larger grey matter volume. Conclusions: The anti-inflammatory effects of dietary Mg intake in the general population, appears to mediate its neuroprotective effect. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor 1 (IGF-1), primarily synthesized in the liver, was initially discovered due to its capacity to replicate the metabolic effects of insulin. Subsequently, it emerged as a key regulator of the actions of growth hormone (GH), managing critical processes like cell proliferation, differentiation, and apoptosis. Notably, IGF-1 displays a longer half-life compared to GH, making it less susceptible to factors that may affect GH concentrations. Consequently, the measurement of IGF-1 proves to be more specific and sensitive when diagnosing conditions such as acromegaly or GH deficiency. The recognition of the existence of IGFBPs and their potential to interfere with IGF-1 immunoassays urged the implementation of various techniques to moderate this issue and provide accurate IGF-1 results. Additionally, in response to the limitations associated with IGF-1 immunoassays and the occurrence of discordant IGF-1 results, modern mass spectrometric methods were developed to facilitate the quantification of IGF-1 levels. Taking advantage of their ability to minimize the interference caused by IGF-1 variants, mass spectrometric methods offer the capacity to deliver robust, reliable, and accurate IGF-1 results, relying on the precision of mass measurements. This also enables the potential detection of pathogenic mutations through protein sequence analysis. However, despite the analytical challenges, the discordance in IGF-1 reference intervals can be attributed to a multitude of factors, potentially leading to distinct interpretations of results. The establishment of reference intervals for each assay is a demanding task, and it requires nationwide multicenter collaboration among laboratorians, clinicians, and assay manufacturers to achieve this common goal in a cost-effective and resource-efficient manner. In this comprehensive review, we examine the challenges associated with the standardization of IGF-1 measurement methods, the minimization of pre-analytical factors, and the harmonization of reference intervals. Particular emphasis will be placed on the development of IGF-1 measurement techniques using "top-down" or "bottom-up" mass spectrometric methods. [ABSTRACT FROM AUTHOR]

The influence of organic solvents such as methanol and acetonitrile on the results of butachlor immunoassay in samples of rice and rice products was studied. The schemes of enzyme immunoassay using: (a) native antiserum containing specific antibodies to butachlor and antispecies antibodies labeled with horseradish peroxidase, and (b) biotinylated specific antibodies and streptavidin labeled with peroxidase are considered. The close values of IC10 (0.77 and 0.68 ng/mL, respectively) and working range (2.6–165 and 2.4–192 ng/mL, respectively) were established for the two schemes, when analyzing in a mixture of phosphate buffer and methanol in a percentage ratio of 85 : 15, respectively. For the second scheme, the detection of butachlor in butachlor in rice-containing products is shown at 80-132% of the added analyte. A comparison of sample preparation methods allows us to recommend: (a) extraction of butachlor with hexane and re-dissolution of the dry residue in a buffer with 15% methanol or (b) preparation of a methanol extract followed by 6-fold dilution with a buffer solution. [ABSTRACT FROM AUTHOR]

In recent years modified bacteriophage lysins have widely been investigated for the purposes of development of antibacterial therapy. Thus, effective and precise methods for the quantitative analysis of these enzymes are in high demand. The enzyme-linked immunosorbent assay (ELISA) method has been developed for the detection of recombinant modified endolysin LysAm24-SMAP in biological samples. The optimal parameters for protein detection were determined, in particular, the influence of salt and the composition of the buffer system for preparation of the samples was studied. The applicability of the immunodetection system of the genetically engineered endolysin LysAm24-SMAP in various biological samples with enzyme concentrations from 0.4 ng/mL was demonstrated. In addition, the influence of matrix effects in samples of animal organs and tissue homogenates and producer strain lysates and their individual components during the analysis was assessed and it was shown that 0.65 M NaCl addition in the ELISA buffer is crucial for achieving correct results and reduces nonspecific interactions in the case of LysAm24-SMAP. The effectiveness of the developed system in the immunochemical control of the bacteriolytic enzyme was confirmed. [ABSTRACT FROM AUTHOR]

The widespread use of antibiotics, leading to antibiotic resistance and the appearance of antibiotics in the environment and food, has stimulated the development of new methods for monitoring antibacterial drugs in environmental objects. One of the promising areas for the development of methods for determining antibiotics is sensor technologies. The key point in the development of sensory systems is the selection of a sensitive (recognizing) element. One of the most popular methods for recognizing antibiotics is the use of antibodies. The main immunosensory systems based on recording the "antigen–antibody" interaction are presented, and the advantages and disadvantages of polyclonal and monoclonal antibodies are shown. The possibility of using phage antibodies to determine antibiotics is described separately. [ABSTRACT FROM AUTHOR]

Saxitoxin (STX), an exceptionally potent marine toxin for which no antidote is currently available, is produced by methanogens and cyanobacteria. This poses a significant threat to both shellfish aquaculture and human health. Consequently, the development of a rapid, highly sensitive STX detection method is of great significance. The objective of this research is to create a novel approach for identifying STX. Therefore, amplified luminescent proximity homogeneous assay (AlphaLISA) was established using a direct competition method based on the principles of fluorescence resonance energy transfer and antigen–antibody specific binding. This method is sensitive, rapid, performed without washing, easy to operate, and can detect 8–128 ng/mL of STX in only 10 min. The limit of detection achieved by this method is as low as 4.29 ng/mL with coefficients of variation for the intra-batch and inter-batch analyses ranging from 2.61% to 3.63% and from 7.67% to 8.30%, respectively. In conclusion, our study successfully establishes a simple yet sensitive, rapid, and accurate AlphaLISA method for the detection of STX which holds great potential in advancing research on marine biotoxins. [ABSTRACT FROM AUTHOR]

Findings from previous studies on maternal 25(OH)D levels during pregnancy and offspring schizophrenia are limited and inconsistent. We used nationwide population-based register data with a nested case-control design to examine the association between maternal 25(OH)D levels during pregnancy and offspring schizophrenia. The cases of schizophrenia (n = 1145) were born from 1987 to 1997, and received a diagnosis of schizophrenia by 2017, and were matched with equal number of controls. A quantitative immunoassay was used to measure maternal 25(OH)D in archived maternal serum in the national biobank of the Finnish Maternity Cohort, collected during the first and early second trimesters. Conditional logistic regression models examined the association between maternal 25(OH)D levels and offspring schizophrenia. No significant association was found between log-transformed maternal 25(OH)D levels and schizophrenia in unadjusted (OR 0.96, 95 % CI 0.78–1.17, p = 0.69) or adjusted analyses (aOR 0.98, 95 % CI 0.79–1.22, p = 0.89). Analyses by quintiles also revealed no association between the lowest quintile of maternal 25(OH)D levels and schizophrenia (OR 1.09, 95 % CI 0.81–1.45, p = 0.55; aOR 1.06, 95 % CI 0.78–1.45, p = 0.71). Maternal 25(OH)D levels, measured in categories, either in deficient category (OR 1.07 (0.85–1.35), p = 0.52; aOR 1.05 (0.81–1.34), p = 0.88) or insufficient category (OR 1.13, 95 % CI 0.92–1.40, p = 0.23; aOR 1.13, 95 % CI 0.90–1.41, p = 0.27) were also not associated with offspring schizophrenia. Maternal vitamin D levels in early pregnancy were not associated with offspring schizophrenia. Future studies measuring vitamin D during different stages of gestation are needed to draw firm conclusions. [ABSTRACT FROM AUTHOR]

Key Clinical Message: When self‐administration with counterfeit or mislabeled medicine is suspected, comprehensive laboratory analysis should be preferred over immunoassay screening to avoid false negative results. Carisoprodol, which was formerly a popular muscle relaxant drug in many countries, has reappeared on illegal drug markets, and may cause an itching, purple‐colored rash, even after a single dose. [ABSTRACT FROM AUTHOR]

Background: Borolatonin is a potential therapeutic agent for some neuronal diseases such as Alzheimer's disease (AD). Its administration exerts ameliorative effects such as those induced by the equimolar administration of melatonin in behavioral tests on male rats and in neuronal immunohistochemistry assays. Objective: In this study, motivated by sex differences in neurobiology and the incidence of AD, the ability of borolatonin to induce changes in female rats was assessed. Methods: Effects of borolatonin were measured by the evaluation of both behavioral and immunohistopathologic approaches; additionally, its ability to limit amyloid toxicity was determined in vitro. Results: Surprisingly, behavioral changes were similar to those reported in male rats, but not those evaluated by immunoassays regarding neuronal survival; while pro‐brain‐derived neurotrophic factor (BDNF) immunoreactivity and the limitation of toxicity by amyloid in vitro were observed for the first time. Conclusion: Borolatonin administration induced changes in female rats. Differences induced by the administration of borolatonin or melatonin could be related to the differences in the production of steroid hormones in sex dependence. Further studies are required to clarify the possible mechanism and origin of differences in disturbed memory caused by the gonadectomy procedure between male and female rats. [ABSTRACT FROM AUTHOR]

A 3D-printed stereolithographic platform for selective biorecognition is designed to enable convective microscale affinity extraction of microcystin-LR (MC-LR) followed by direct solid-phase optosensing exploiting ratiometric front-face fluorescence spectroscopy. For this purpose, a recombinant monoclonal plantibody (recAb) is covalently attached to a 3D-printed structure for sorptive immunoextraction, whereupon the free and unbound primary amino moieties of the recAb are derivatized with a fluorescent probe. The fluorophore-recAb-MC-LR laden device is then accommodated in the cuvette holder of a conventional fluorometer without any instrumental modification for the recording of the solid-phase fluorescence emission. Using Rodbard's four-parameter sigmoidal function, the 3D-printed bioselective platform features a limit of detection (LOD) of 28 ng L−1 using a sample volume of 500 mL, device-to-device reproducibility down to 12%, and relative recoveries ranging from 91 to 100% in marine waters. Printed prototypes are affordable, just 0.4 € per print and ≤ 10 € per device containing recAb. One of the main assets of the miniaturized immunoextraction device is that it performs comparably well in terms of analytical figures of merit with costly mass spectrometric-based analytical methodologies, such as HPLC–MS/MS. The device is readily applicable to high-matrix samples, such as seawater, as opposed to previous biosensing platforms, just applied to freshwater systems. [ABSTRACT FROM AUTHOR]

Purpose: In contrast to adults, immune protection against SARS-CoV-2 in children and adolescents with natural or hybrid immunity is still poorly understood. The aim of this study was to analyze different immune compartments in different age groups and whether humoral immune reactions correlate with a cellular immune response. Methods: 72 children and adolescents with a preceding SARS-CoV-2 infection were recruited. 37 were vaccinated with an RNA vaccine (BNT162b2). Humoral immunity was analyzed 3–26 months (median 10 months) after infection by measuring Spike protein (S), nucleocapsid (NCP), and neutralizing antibodies (nAB). Cellular immunity was analyzed using a SARS-CoV-2-specific interferon-γ release assay (IGRA). Results: All children and adolescents had S antibodies; titers were higher in those with hybrid immunity (14,900 BAU/ml vs. 2118 BAU/ml). NCP antibodies were detectable in > 90%. Neutralizing antibodies (nAB) were more frequently detected (90%) with higher titers (1914 RLU) in adolescents with hybrid immunity than in children with natural immunity (62.5%, 476 RLU). Children with natural immunity were less likely to have reactive IGRAs (43.8%) than adolescents with hybrid immunity (85%). The amount of interferon-γ released by T cells was comparable in natural and hybrid immunity. Conclusion: Spike antibodies are the most reliable markers to monitor an immune reaction against SARS-CoV-2. High antibody titers of spike antibodies and nAB correlated with cellular immunity, a phenomenon found only in adolescents with hybrid immunity. Hybrid immunity is associated with markedly higher antibody titers and a higher probability of a cellular immune response than a natural immunity. [ABSTRACT FROM AUTHOR]

Accurate and sensitive near‐infrared (NIR) luminescent lateral flow immunoassay (LFIA) has attracted considerable attention in the field of point‐of‐care testing (POCT). However, the detection accuracy and sensitivity are often compromised by the low fluorescence quantum efficiency (<10%) of the NIR fluorescent probe. Herein, ultrabright NIR AIEgen nanoparticles (PS@AIE830NPs) composed of polystyrene (PS) nanoparticles and NIR aggregation‐induced emission luminogen (AIEgen) with the maximum emission at 830 nm (AIE830) is reported, and its potential to promote an accurate and sensitive detection of complex samples by LFIA is described. The relative quantum yield (QY) of the PS@AIE830NPs was 14.76%, which was superior to that of the polymer embedding method and indocyanine green (ICG)‐based NIR nanoparticles. The PS@AIE830NPs immunolabeled‐LFIA combined with laboratory‐built NIR‐LFIA portable quantitative instruments (detected light range > 800 nm) completely eliminated background interference and allowed highly accurate and sensitive detection without any pre‐treatment steps. The limits of detection (LODs) for aflatoxin B1 (AFB1) in soy sauce, alpha hemolysin (Hla) of Staphylococcus aureus biomarker in joint fluid, and C‐reactive protein (CRP) in human haemolysed samples were 0.01 ng mL−1, 0.02 µg mL−1, and 0.156 mg L−1, respectively, commensurating with those of the corresponding gold standard assays and covering the detection range of interests. It is anticipated that the ultrabright NIR AIEgen nanoparticles will serve as a universally applicable signal probe for NIR‐LFIA diagnostics, promising to expand the range of applications for quantitative detection of complex samples. [ABSTRACT FROM AUTHOR]

Anti‐Spike IgG antibodies against SARS‐CoV‐2, which are elicited by vaccination and infection, are correlates of protection against infection with pre‐Omicron variants. Whether this association can be generalized to infections with Omicron variants is unclear. We conducted a retrospective cohort study with 8457 blood donors in Tyrol, Austria, analyzing 15,340 anti‐Spike IgG antibody measurements from March 2021 to December 2022 assessed by Abbott SARS‐CoV‐2 IgG II chemiluminescent microparticle immunoassay. Using a Bayesian joint model, we estimated antibody trajectories and adjusted hazard ratios for incident SARS‐CoV‐2 infection ascertained by self‐report or seroconversion of anti‐Nucleocapsid antibodies. At the time of their earliest available anti‐Spike IgG antibody measurement (median November 23, 2021), participants had a median age of 46.0 years (IQR 32.8–55.2), with 45.3% being female, 41.3% having a prior SARS‐CoV‐2 infection, and 75.5% having received at least one dose of a COVID‐19 vaccine. Among 6159 participants with endpoint data, 3700 incident SARS‐CoV‐2 infections with predominantly Omicron sublineages were recorded over a median of 8.8 months (IQR 5.7–12.4). The age‐ and sex‐adjusted hazard ratio for SARS‐CoV‐2 associated with having twice the anti‐Spike IgG antibody titer was 0.875 (95% credible interval 0.868–0.881) overall, 0.842 (0.827–0.856) during 2021, and 0.884 (0.877–0.891) during 2022 (all p < 0.001). The associations were similar in females and males (Pinteraction = 0.673) and across age (Pinteraction = 0.590). Higher anti‐Spike IgG antibody titers were associated with reduced risk of incident SARS‐CoV‐2 infection across the entire observation period. While the magnitude of association was slightly weakened in the Omicron era, anti‐Spike IgG antibody continues to be a suitable correlate of protection against newer SARS‐CoV‐2 variants. [ABSTRACT FROM AUTHOR]

Background: Due to lower operational costs, health maintenance organizations (HMOs) may prioritize Helicobacter pylori stool antigen testing (HpStAg) for the non-invasive diagnosis of H. pylori infection over 13C-urea breath tests (13C-UBTs). The aim of our study was to compare the accuracy of the diagnostic tests for H. pylori. Methods: We performed histology, rapid urease test (RUT), 13C-UBT and HpStAg on consecutive patients referred for gastroscopy. Monoclonal stool antigen test was performed using the LIAISON Meridian chemiluminescent immunoassay. Histology was examined with hematoxylin and eosin, and additional stains were performed at the pathologist's discretion. For the assessment of 13C-UBT, we compared concordant histology and RUT. HpStAg was compared to the concordant results of two of the three remaining tests. Results: 103 patients were included (36 males (35.0%), age 50.1 ± 18.4 years). The indication for gastroscopy was dyspepsia in 63 (61.2%). Agreement between RUT and histology was 95.9%. For 13C-UBT and HpStAg, respectively, H. pylori positivity was 30% (30/100) and 27.16% (22/81); sensitivity was 97% and 70%; specificity was 100% and 94.4%; accuracy was 98% and 86%; positive predictive value (PPV) was 100% and 86.4%; negative predictive value (NPV) was 93% and 86%. No demographic, clinical, or endoscopic predictors of HpStAg accuracy were identified using logistic regression. Conclusions: 13C-UBT performs better than HpStAg at our institution. When interpreting results, clinicians should consider test limitations. [ABSTRACT FROM AUTHOR]

To explore the usefulness of neutrophil-to-lymphocyte count ratio (NLR), procalcitonin (PCT), and interleukin-6 (IL-6) for the severity assessment of bacterial sepsis. This study enrolled 100 patients with bacterial sepsis (disease group) who presented to Jinhua Central Hospital between March 2022 and March 2023 and 90 healthy individuals (control group). The patients were categorized into sepsis (64 cases), severe sepsis (18 cases), and septic shock (18 cases) groups according to the disease severity. The groups were compared in terms of the NLR, PCT, and IL-6, as well as the usefulness of these parameters, both alone and in combination, for the severity assessment of bacterial sepsis. The NLR, PCT, and IL-6 levels were significantly different among the three groups, with increasing values corresponding with disease aggravation. The area under the curve (AUC) values of the combinations of NLR, PCT, and IL-6 levels were higher than those of single markers. The sensitivity and AUC value of the combination of PCT and IL-6 levels were the highest (0.87), with a similar AUC value of the combination of NLR, PCT, and IL-6 (0.865); however, the specificity was significantly improved with the latter (0.938 vs. 0.859). NLR, PCT, and IL-6 levels are significantly increased in bacterial sepsis, and the combination of PCT, and IL-6 levels can improve the sensitivity of the evaluation ability for severe sepsis, and is more economical. [ABSTRACT FROM AUTHOR]

Catalytic nanoparticle@metal‐organic framework (MOF) composites have attracted significant interest in point‐of‐care testing (POCT) owing to their prominent catalytic activity. However, the trade‐off between high loading efficiency and high catalytic activity remains challenging because high concentrations of nanoparticles tend to cause the misjoining and collapse of the MOFs. Herein, a facile strategy is reported to encapsulate high concentrations of platinum (Pt) nanoparticles into zeolitic imidazolate framework‐8 (ZIF‐8) using polydopamine (PDA) as a support for Pt@ZIF‐8 and as a flexible scaffold for further immobilization of Pt nanoparticles. The resulting composite (Pt@ZIF‐8@PDA@Pt) exhibits ultrahigh Pt nanoparticle loading efficiency, exceptional catalytic activity, stability, and a bright colorimetric signal. Following integration with lateral flow immunoassay (LFIA), the detection limits for pre‐ and post‐catalysis detection of B‐type natriuretic peptide (NT‐proBNP) are 0.18 and 0.015 ng mL−1, respectively, representing a 6‐fold and 70‐fold improvement compared to gold nanoparticle‐based LFIA. Moreover, Pt@ZIF‐8@PDA@Pt‐based LFIA achieves 100% diagnostic sensitivity for NT‐proBNP in a cohort of 184 clinical samples. [ABSTRACT FROM AUTHOR]

Objective: Ghrelin is an orexigenic peptide that becomes post-translationally modified. Natural autoantibodies to ghrelin (ghrelin-aAb) have been described in healthy subjects, in eating disorders and rheumatic diseases, with potential clinical relevance. Despite these important reports, the data base on the prevalence and physiological role is small and technical approaches for assessing ghrelin-aAb are few, encouraging respective research for improving knowledge on the potential endocrine significance. Methods: A novel immunoprecipitation assay was generated based on a fusion protein of human ghrelin with a reporter gene. Assay quality was verified with commercial antibodies. Assay characteristics and matrix effects were determined, including stability of natural ghrelin-aAb to freezing, signal linearity in dilution experiments, and comparison of different matrices. Three groups of serum samples were analyzed for ghrelin-aAb, comprising commercial sera from healthy subjects and patients with type 1 or type 2 diabetes mellitus. Results: The newly generated ghrelin-aAb assay proved sensitive, robust and reliable over a broad concentration range. Results from serum and plasma differed slightly. The signals from serum remained stable towards freezing and thawing, and in dilution experiments. Applying a mathematical criterion for outliers (P75 + 1.5-times IQR), an average prevalence of 11%–12% of positive samples was identified in the different human cohorts, with no significant sexor disease-related difference. General significance: A novel diagnostic autoantibody assay detected ghrelinaAb with a similar prevalence in diabetic patients and controls, suggesting that autoimmunity to ghrelin plays little role in diabetes mellitus, but may be of relevance in other diseases where ghrelin signaling is essential. [ABSTRACT FROM AUTHOR]