Radiological outpatient' visits to avoid inappropriate cardiac CT examinations: an 8-year experience report.

PURPOSE: The aim of this study was to evaluate the appropriateness of the cardiac computed tomography angiography (CCTA) prescriptions according to the "2010-Appropriate-Use-Criteria-for-Cardiac-Computed-Tomography-Angiography" (AUCCTA) and "Clinical-indication-for-CCTA" (CICCTA) among different specialities (Cardiologist [CA], General Practitioner [GP], Other Specialists [OS]) and prescribers' age. MATERIALS AND METHODS: This is a single-centre, single-arm, cohort study. We prospectively enrolled 815 patients (October 2012-May 2019) who underwent a radiological outpatient visit, before CCTA examination. Prescriptions to the examination were categorized as follows: Appropriate (A), Uncertain (U) and Inappropriate (Ina), according to AUCCTA and I, II, III and Inv for CICCTA. This categorization was stratified according to CA, GP and OS and prescribers' age. CCTA was performed in patients whom indications belong to A/U categories. RESULTS: Eight hundred and fifteen CCTA prescriptions were analysed. An yearly increase in prescriptions was found in the eight-year observational period (2012/2019 projection: 72 vs 223). Considering AUCCTA, indication A was 540/815 (66.3%), indication U was 113/815 (13.9%) and Ina accounted for 162/815 (19.9%; 128/162 [79.0%] indications with stress test listed as criterium of inappropriateness). Only U indications decreased over years (p = 0.003). Regarding CICCTA, 501/815 (61.5%) patients were categorized as I, 144/815 (17.7%) as II, 102/815 (12.5%) as III, 67/815 (8.2%) were INV and 1/815 (0.1%) were non-classified. Clinical referrals were CA in 495/786 (63.0%), GPs in 57/786 (7.3%) GP and OS in 234/786 (29.8%) [p < 0.01]. No statistically significant differences were observed in the appropriateness among different specialty physicians. Younger doctors have a lower chance to not meet A indication (OR 0.98 [CI 95% 0.96-0.99]; p = 0.003). CONCLUSION: Our study highlights the importance of a pre-radiological visit prior to CCTA, which prevented execution of 19.9% of inappropriate examinations. Age of prescribers had an impact on appropriateness, with younger doctors having a lower chance to not meet A indication.

Silver and gold nanoparticles as multi-chromatic lateral flow assay probes for the detection of food allergens.

In this study, we report the simultaneous use of gold and silver nanoparticles to set a multicolor multiplex lateral flow immunoassay (xLFIA). Silver nanoparticles (AgNPs), spherical in shape and characterized by a brilliant yellow color, were obtained by a new viable one-step synthetic protocol. AgNPs were stable over time and acceptably robust to conditions used for fabricating LFIA devices. These AgNPs were employed as a colorimetric probe in combination with two different kinds of gold nanoparticles (AuNPs) to set a visual xLFIA for detecting allergens. Surface plasmon resonance peaks of probes (AgNPs, spherical and desert rose-like AuNPs) were centered at 420, 525, and 620 nm, respectively. Therefore, the xLFIA output was easily interpreted through a "yellow magenta cyan (YMC)" color code. The prospect of the YMC xLFIA was demonstrated by simultaneously detecting three major allergens in bakery products. Antibodies directed towards casein, ovalbumin, and hazelnut allergenic proteins were individually adsorbed onto metal nanoparticles to produce three differently colored specific probes. These were inserted in a LFIA comprising three lines, each responsive for one allergen. The trichromatic xLFIA was able to detect allergenic proteins at levels as low as 0.1 mg/l and enabled the easy identification of the allergens in commercial biscuits based on the color of the probes. Graphical Abstract.

A versatile and sensitive lateral flow immunoassay for the rapid diagnosis of visceral leishmaniasis.

Visceral leishmaniasis (VL) is a zoonotic infectious disease with a severe impact on humans and animals. Infection is transmitted by phlebotomine sand flies, and several domestic and wild mammals act as reservoirs for the infection, so the prompt detection of infected hosts is crucial to preventing and controlling the spread of the disease and its transmission to humans. A rapid and portable tool for VL diagnosis based on the lateral flow immunoassay (LFIA) technology is described herein. The device exploits a highly specific chimeric recombinant antigen as the recognition element for capturing anti-leishmanial antibodies, and protein A labelled with gold nanoparticles as the signal reporter. The LFIA shows excellent diagnostic sensitivity (98.4%), specificity (98.9%), and agreement with serological reference methods for diagnosing canine VL. The long-term stability of the LFIA device was confirmed based on six months of storage at room temperature or 4 °C, and the qualitative response of the device was not affected by limited thermal stress. The use of the broadly specific protein A means that the LFIA can be readily adapted to diagnose VL in dogs (the main reservoir for human infection) and other mammals, thus further assisting efforts to control the spread of VL. Graphical abstract A rapid and portable diagnostic tool for visceral leishmaniasis (VL) based on lateral flow immunoassay (LFIA) technology. The presence of anti-leishmanial antibodies is revealed through the binding of these antibodies to a highly specific chimeric antigen. Employing a broadly specific signal reporter (protein A labelled with gold nanoparticles) enables the LFIA to be easily adapted to diagnose VL in different animals.

A lateral flow immunoassay for straightforward determination of fumonisin mycotoxins based on the quenching of the fluorescence of CdSe/ZnS quantum dots by gold and silver nanoparticles.

A lateral flow immunoassay (LFIA) was developed for the determination of fumonisin mycotoxins. The fluorescence of CdSe/ZnS quantum dots (QDs), observed at excitation/emission wavelengths of 365/525 nm, is suppressed by the addition of silver nanoparticles (SNPs) or gold nanoparticles (GNPs) because SNPs overlap the excitation bands of the QDs, and GNPs overlap the emission bands. The fluorescence of the QDs is recovered upon addition of fumonisins, allowing for the sensitive detection in "positive mode" of the target mycotoxin by monitoring the changes of the QDs fluorescence intensity. The SNPs are found to be the most effective quenchers, while the use of GNPs allows for an efficient recovery of fluorescence and can be employed in the LFIA. The method was successfully applied to the fluorometric determination of fumonisins in spiked maize flour samples. The visual detection limit is at the ng·mL-1 level. This is four times lower compared to the colorimetric LFIA based on the use of the conventional gold NPs. Graphical abstract Schematic of the fluorescence quenching lateral flow immunoassay that uses fluorescent quantum dots (QD) and metal nanoparticles (NP) as the quencher: the binding of NP-labelled antibody to the antigen (purple triangle) modulates QD luminescence at the Test line, allowing for 'positive mode' detection of fumonisins. The NP accumulation at Control line assures validity of the test.

Comparison of binding behavior for molecularly imprinted polymers prepared by hierarchical imprinting or Pickering emulsion polymerization.

The aim of this study was the evaluation of the binding performances and selectivity of molecularly imprinted beads prepared toward several penicillins (i) by hierarchical bulk polymerization in the pores of template-grafted silica microbeads (hMIPs) and (ii) by Pickering emulsion polymerization in the presence of template-decorated silica nanobeads (pMIPs). 6-Aminopenicillanic acid was chosen as the common fragmental mimic template. Both approaches produced micron-sized polymeric beads with good recognition properties toward the target ligands whereas the selectivity pattern appeared quite different. The polymer prepared by the Pickering emulsion approach showed binding properties similar to imprinted beads prepared by hierarchical approach. Equilibrium binding constants changed their values from 0.1-0.2 × 10(6) (hMIPs) to 0.2-0.6 × 10(6) M(-1) (pMIPs), while the binding site densities changed from 3.7-4.8 (hMIPs) to 0.3-0.55 µmol/g (pMIPs). Compared to the hierarchical polymerization, Pickering emulsion polymerization represents a more practical approach when a template mimic needs to be used.

In Vitro Antibody Quantification with Hyperspectral Imaging in a Large Field of View for Clinical Applications.

Hyperspectral imaging (HSI) is a non-invasive, contrast-free optical-based tool that has recently been applied in medical and basic research fields. The opportunity to use HSI to identify exogenous tumor markers in a large field of view (LFOV) could increase precision in oncological diagnosis and surgical treatment. In this study, the anti-high mobility group B1 (HMGB1) labeled with Alexa fluorophore (647 nm) was used as the target molecule. This is the proof-of-concept of HSI's ability to quantify antibodies via an in vitro setting. A first test was performed to understand whether the relative absorbance provided by the HSI camera was dependent on volume at a 1:1 concentration. A serial dilution of 1:1, 10, 100, 1000, and 10,000 with phosphatase-buffered saline (PBS) was then used to test the sensitivity of the camera at the minimum and maximum volumes. For the analysis, images at 640 nm were extracted from the hypercubes according to peak signals matching the specificities of the antibody manufacturer. The results showed a positive correlation between relative absorbance and volume (r = 0.9709, p = 0.0013). The correlation between concentration and relative absorbance at min (1 µL) and max (20 µL) volume showed r = 0.9925, p < 0.0001, and r = 0.9992, p < 0.0001, respectively. These results demonstrate the HSI potential in quantifying HMGB1, hence deserving further studies in ex vivo and in vivo settings.

Harnessing the power of RNA therapeutics in treating ischemic heart failure: the TRAIN-HEART story.

Ischemic heart disease (IHD) is one of the world's foremost killers, accounting for 16% of all deaths worldwide. IHD is the main cause of heart failure (HF), as it leads to pathological changes in the heart, improper pumping function and eventual death. Therapeutic interventions usually follow a systemic general strategy for all heart failure subtypes due to the lack of a deep understanding of the disease mechanisms. Hence, HF and IHD therapeutics need groundbreaking concepts to guide the development of a new therapeutics class that tackles the disease at a molecular level. The TRAIN-HEART consortium, a Marie Sklodowska-Curie Actions Innovative Training Network (MSCA-ITN) funded by the European Commission, was established with the goal of filling that gap and developing RNA-based cardiovascular therapeutics. Created in the context of the Horizon 2020 research and innovation program, TRAIN-HEART comprises three key work packages (WPs) focusing on the pathogenesis of heart disease (WP1), the therapeutic potential of RNA therapeutics (WP2), and the development of new efficient delivery systems (WP3). Fifteen international early stage researchers (ESRs) from multiple complementary scientific disciplines were recruited to collaborate with a network of PIs from nine academic and eight non-academic partners in various disciplines to fully harness their collective potential for the betterment of HF treatment. This article provides an overview of the benefits of being part of an MSCA-ITN, with its different training and networking opportunities, maximizing ESRs' potential and broadening collaborative research possibilities. Finally, it describes what was like to do a PhD during the COVID-19 pandemic, with all the uncertainty and concern attached to it. Luckily, TRAIN-HEART stood out as a proactive network, finding new initiatives and alternatives to promote scientific and personal development. By bringing together leading academic teams, (biotech) companies, and highly motivated researchers, TRAIN-HEART is expanding scientific horizons and accelerating future development of effective RNA-based therapies to treat IHD.

Stoichiometric molecular imprinting using polymerisable urea and squaramide receptors for the solid phase extraction of organo-arsenic compound roxarsone.

The design, preparation and evaluation of molecularly imprinted polymers for roxarsone (4-hydroxy-3-nitrophenylarsonic acid), an organo-arsenic swine and poultry feed additive, using bi-substituted ureas and squaramide receptors as the functional monomers, are demonstrated. Pre-polymerisation studies of the template-monomer complexation performed by 1H NMR experiments show that squaramide-based monomers provide association equilibrium constant values higher than urea-based monomers. Equilibrium rebinding experiments in methanol show that two squaramide-based materials have good molecular recognition properties towards roxarsone, with high affinity (Keq = 16.85 × 103 L mol-1 and 14.65 × 103 L mol-1, respectively), high imprinting factors (4.73 and 3.64 respectively) and good selectivity towards two roxarsone-related compounds, acetarsone (3-acetamido-4-hydroxyphenylarsonic acid) and nitarsone (4-nitrophenylarsonic acid). Polymer MIP-SQ2 was successfully used to setup an experimental protocol for the direct solid phase extraction of roxarsone from surface water samples. The method gives clean HPLC traces, with recoveries between 91% and 95% at concentration levels of 5.0, 10, and 25 mg L-1. Sample preconcentration with good recoveries between 87% and 97%, are shown, confirming that it is possible to employ the developed materials to measure roxarsone down to 1 µg L-1 in water samples.

Delayed Addition of Template Molecules Enhances the Binding Properties of Diclofenac-Imprinted Polymers.

It has been reported that in the molecular imprinting technique, the use of preformed oligomers instead of functional monomers increases the stability of the non-covalent interactions with the template molecule, providing a sharp gain in terms of binding properties for the resulting imprinted polymer. Based on this theory, we assumed that the delayed addition of template molecules to a polymerization mixture enhances the binding properties of the resulting polymer. To verify this hypothesis, we imprinted several mixtures of 4-vinylpyridine/ethylene dimethacrylate (1:6 mol/mol) in acetonitrile by adding diclofenac progressively later from the beginning of the polymerization process. After polymerization, the binding isotherms of imprinted and non-imprinted materials were measured in acetonitrile by partition equilibrium experiments. Binding data confirm our hypothesis, as imprinted polymers prepared by delayed addition, with delay times of 5 and 10 min, showed higher binding affinity (Keq = 1.37 × 104 L mol-1 and 1.80 × 104 L mol-1) than the polymer obtained in the presence of template at the beginning (Keq = 5.30 × 103 L mol-1). Similarly, an increase in the imprinting factor measured vs. the non-imprinted polymer in the binding selectivity with respect to mefenamic acid was observed. We believe that the delayed addition approach could be useful in prepar imprinted polymers with higher binding affinity and increased binding selectivity in cases of difficult imprinting polymerization.

Impact of the gut microbiota on the m6A epitranscriptome of mouse cecum and liver.

The intestinal microbiota modulates host physiology and gene expression via mechanisms that are not fully understood. Here we examine whether host epitranscriptomic marks are affected by the gut microbiota. We use methylated RNA-immunoprecipitation and sequencing (MeRIP-seq) to identify N6-methyladenosine (m6A) modifications in mRNA of mice carrying conventional, modified, or no microbiota. We find that variations in the gut microbiota correlate with m6A modifications in the cecum, and to a lesser extent in the liver, affecting pathways related to metabolism, inflammation and antimicrobial responses. We analyze expression levels of several known writer and eraser enzymes, and find that the methyltransferase Mettl16 is downregulated in absence of a microbiota, and one of its target mRNAs, encoding S-adenosylmethionine synthase Mat2a, is less methylated. We furthermore show that Akkermansia muciniphila and Lactobacillus plantarum affect specific m6A modifications in mono-associated mice. Our results highlight epitranscriptomic modifications as an additional level of interaction between commensal bacteria and their host.

Colour-encoded lateral flow immunoassay for the simultaneous detection of aflatoxin B1 and type-B fumonisins in a single Test line.

A multiplex Lateral Flow Immunoassay was developed based on the use of a single Test line and multicolour gold nanoparticles (GNPs) as signal reporters. Red and blue GNPs were linked to antibodies directed towards two different analytes and included in a typical lateral flow immunoassay configuration, in which the Test line was formed by the mixture of two antigens. As a result of the immunoreactions occurring at the Test zone, diverse combinations of red and blue GNPs labels were captured. Therefore, the Test line assumed different colours depending on which - and how much - analyte is present in the sample. The multiplexing capability of the 'colour-encoded assay' is illustrated by the simultaneous detection of aflatoxin B1 (AFB1) and type-B fumonisins (FMs) in wheat and food products that made with wheat. Reproducible detection of AFB1 and FMs contamination in raw and processed food was achieved with visual cut-off levels at 1 ng mL-1 and 50 ng mL-1, respectively. The contaminant was identified based on the colour of the label according with a specific colour code. Furthermore, strips images were acquired by means of a common smartphone and analysed through RGB data analysis providing semi-quantitative detection of the two mycotoxins.

Screening of a Combinatorial Library of Organic Polymers for the Solid-Phase Extraction of Patulin from Apple Juice.

Patulin is a water-soluble mycotoxin produced by several species of fungi. Governmental bodies have placed it under scrutiny for its potential negative health effects, and maximum residue limits are fixed in specific food matrices to protect consumers' health. Confirmatory analysis of patulin in complex food matrices can be a difficult task, and sample clean-up treatments are frequently necessary before instrumental analyses. With the aim of simplifying the clean-up step, we prepared a 256-member combinatorial polymeric library based on 16 functional monomers, four cross-linkers and four different porogenic solvents. The library was screened for the binding towards patulin in different media (acetonitrile and citrate buffer at pH 3.2), with the goal of identifying polymer formulations with good binding properties towards the target compound. As a proof of concept, a methacrylic acid-co-pentaerithrytole tetraacrylate polymer prepared in chloroform was successfully used as a solid-phase extraction material for the clean-up and extraction of patulin from apple juice. Clean chromatographic patterns and acceptable recoveries were obtained for juice spiked with patulin at concentration levels of 25 (64 ± 12%), 50 (83 ± 5.6%) and 100 µg L-1 (76 ± 4.5%). The within-day and between-day reproducibility evaluated at a concentration level of 25 µg L-1 were 5.6 and 7.6%, respectively.