Use of Therapeutic Drug Monitoring in Amiodarone Treatment: A Systematic Review of Recent Literature.

BACKGROUND: Amiodarone is a class III antiarrhythmic drug used to prevent supraventricular and ventricular tachyarrhythmias. It has substantial toxicity; however, the use of therapeutic drug monitoring (TDM) seems unclear in the absence of a therapeutic range or an association between amiodarone blood concentration and effect. In this review, the authors examined the reported amiodarone blood concentration measurements in the last 10 years and subsequently noted the frequency by which TDM was used to optimize therapy. METHODS: In March 2022, the Embase and MEDLINE databases were searched for articles published in English in the previous 10 years using the keywords "amiodarone," "therapeutic drug monitoring," or "serum/plasma/blood". RESULTS: This study included 19 of the 478 articles identified. TDM has not been studied in conjunction with regular amiodarone maintenance therapy. One study used TDM during the initial treatment phase but the amiodarone dose was not changed. In 3 other case reports, TDM was used to guide amiodarone treatment through drug-drug interactions, and plasma levels of the active metabolite mono-N-desethyl-amiodarone (MDEA) verified 2 amiodarone toxicities. CONCLUSIONS: Because the antiarrhythmic effect of amiodarone is not correlated with blood concentrations and is easily detectable by electrocardiogram, the routine use of TDM in maintenance therapy is controversial, as evidenced by a scarcity of published literature in the recent decade. Furthermore, amiodarone toxicity is evident with normal/low amiodarone or MDEA levels; hence, TDM of amiodarone provides no therapeutic benefit to patients.

A simple screening strategy for complex RNA-DNA hybrid nanoshapes.

The design of hybrid nucleic acid nanomaterials capitalizes on the partitioning of architectural and functional roles between structurally diverse RNA modules and chemically robust DNA components. Selecting optimal combinations of RNA and DNA building blocks is the key to preparing stable polygonal RNA-DNA hybrid nanoshapes. Here, we outline a simple screening strategy by gel electrophoresis under native folding conditions to identify combinations of RNA and DNA modules that self-assemble to robust polygonal hybrid nanoshapes. As a proof of concept, we outline the preparation of RNA-DNA hybrid nanoshapes containing a set of different RNA architectural joints, including internal loop motifs and three-way junction (3WJ) folds. For each hybrid nanoshape, we demonstrate the selection process used to identify optimal DNA modules from a library of DNA connectors. The simple screening strategy outlined here provides a general robust method to identify and prepare RNA-DNA hybrid nanoshapes from diverse libraries of discrete nucleic acid building blocks.

Nano-sandwich composite by kinetic trapping assembly from protein and nucleic acid.

Design and preparation of layered composite materials alternating between nucleic acids and proteins has been elusive due to limitations in occurrence and geometry of interaction sites in natural biomolecules. We report the design and kinetically controlled stepwise synthesis of a nano-sandwich composite by programmed noncovalent association of protein, DNA and RNA modules. A homo-tetramer protein core was introduced to control the self-assembly and precise positioning of two RNA-DNA hybrid nanotriangles in a co-parallel sandwich arrangement. Kinetically favored self-assembly of the circularly closed nanostructures at the protein was driven by the intrinsic fast folding ability of RNA corner modules which were added to precursor complex of DNA bound to the protein. The 3D architecture of this first synthetic protein-RNA-DNA complex was confirmed by fluorescence labeling and cryo-electron microscopy studies. The synthesis strategy for the nano-sandwich composite provides a general blueprint for controlled noncovalent assembly of complex supramolecular architectures from protein, DNA and RNA components, which expand the design repertoire for bottom-up preparation of layered biomaterials.

Sonification enables continuous surveillance of the ST segment in the electrocardiogram.

INTRODUCTION: ST segment elevation myocardial infarction is a common reason for out-of-hospital cardiac arrest in adult patients. The surveillance of the ST segment in the electrocardiogram is limited to visual presentation. However, the ST segment can change during the course of treatment. If ST elevation is present immediate coronary revascularization is needed, therefore detecting ST elevation changes the treatment fundamentally. Sonification of the ST segment is a new method which enables the emergency team to detect intermediate changes of the ST segment. MATERIAL AND METHODS: We have chosen two sonification designs which were introduced to two groups, medical students and computer science students. Twenty-one participants took part in the study. The sonification was designed for evaluation of the ST segment. The user was supposed to become empowered to distinguish between no, medium-low, medium-high or extreme ST elevation by listening to the sonification. The two groups were asked to evaluate the sounds for possible ST elevation as well as for aesthetics and usability. In a second study twenty-five medical students were taking part in a medical scenario in which sonification was played during a simulated case. The patient was suffering from a myocardial infarction, ST elevation was transient and sonification sounds were changing appropriately. The students were supposed to detect these changes and act accordingly by modifying the treatment. RESULTS: Both groups were able to classify ST segment elevation by listening to the sonification samples. The higher the ST segment, the better was the detection rate overall. In all of the three categories (pleasantness, informativeness and long-term listening) the Water Ambience sonification was rated higher compared to the Polarity sonification. Moreover, in the two groups that took part in the study, we found a significant difference when comparing classification performance using both sonification designs. For the group of medical students as t(20) = 4.31, p = 3.44 × 10-4, p < 0.01 and for the computer science students as t(19) = 3.40, p = 9.39 × 10-6, p < 0.01. In the simulated medical scenario participants indicated that 96% detected the ST elevation. 60% stated that sonification played a role whereas for 32% it did not play a role for the detection of ST elevation. CONCLUSIONS: Sonification has the potential to play an important role as a new supporting tool for the surveillance of the ST segment during the care of patients with suspicion of myocardial infarction. It can be helpful to differentiate between ST segment elevation myocardial infarction and non-ST segment myocardial infarction especially if ST elevation is transient. Furthermore, sonification is viewed as pleasant to listen to and might not contribute to alarm fatigue.

RNA-DNA Hybrid Nanoshape Synthesis by Facile Module Exchange.

The preparation of nucleic acid nanostructures has relied predominantly on procedures of additive fabrication in which complex architectures are assembled by concerted self-assembly and sequential addition of building blocks. We had previously established RNA-DNA hybrid nanoshapes with modular architectures that enable multistep synthetic approaches inspired by organic molecular synthesis where additive and transformative steps are used to prepare complex molecular architectures. We report the establishment of module replacement and strand exchange as synthetic transformations in nucleic acid hybrid nanoshapes, which are enabled by minimally destabilizing sequence elements such as a single unpaired overhang nucleotide or a mismatch base pair. Module exchange facilitated by thermodynamic lability triggers adds a powerful transformative approach to the repertoire of additive and transformative synthetic methods for the preparation of complex composite materials.

Psychological care in children and adolescents with type 1 diabetes in a real-world setting and associations with metabolic control.

BACKGROUND: International guidelines recommend psychosocial care for children and adolescents with type 1 diabetes. OBJECTIVE: To assess psychological care in children and adolescents with type 1 diabetes in a real-world setting and to evaluate associations with metabolic outcome. METHODS: Delivery of psychological care, HbA1c, and rates of severe hypoglycemia and diabetic ketoacidosis (DKA) in children and adolescents with type 1 diabetes from 199 diabetes care centers participating in the German diabetes survey (DPV) were analyzed. RESULTS: Overall, 12 326 out of 31 861 children with type 1 diabetes were supported by short-term or continued psychological care (CPC). Children with psychological care had higher HbA1c (8.0% vs 7.7%, P<.001) and higher rates of DKA (0.032 vs 0.021 per patient-year, P<.001) compared with children without psychological care. In age-, sex-, diabetes duration-, and migratory background-matched children, HbA1c stayed stable in children supported by CPC during follow-up (HbA1c 8.5% one year before psychological care started vs 8.4% after two years, P = 1.0), whereas HbA1c was lower but increased significantly by 0.3% in children without psychological care (HbA1c 7.5% vs 7.8% after two years, P <.001). Additional HbA1c-matching showed that the change in HbA1c during follow-up was not different between the groups, but the percentage of children with severe hypoglycemia decreased from 16.3% to 10.7% in children receiving CPC compared with children without psychological care (5.5% to 5.8%, P =.009). CONCLUSIONS: In this real-world setting, psychological care was provided to children with higher HbA1c levels. CPC was associated with stable glycemic control and less frequent severe hypoglycemia during follow-up.

Prediction of obstructive coronary artery disease and prognosis in patients with suspected stable angina.

AIMS: We hypothesized that the modified Diamond-Forrester (D-F) prediction model overestimates probability of coronary artery disease (CAD). The aim of this study was to update the prediction model based on pre-test information and assess the model's performance in predicting prognosis in an unselected, contemporary population suspected of angina. METHODS AND RESULTS: We included 3903 consecutive patients free of CAD and heart failure and suspected of angina, who were referred to a single centre for assessment in 2012-15. Obstructive CAD was defined from invasive angiography as lesion requiring revascularization, >70% stenosis or fractional flow reserve <0.8. Patients were followed (mean follow-up 33 months) for myocardial infarction, unstable angina, heart failure, stroke, and death. The updated D-F prediction model overestimated probability considerably: mean pre-test probability was 31.4%, while only 274 (7%) were diagnosed with obstructive CAD. A basic prediction model with age, gender, and symptoms demonstrated good discrimination with C-statistics of 0.86 (95% CI 0.84-0.88), while a clinical prediction model adding diabetes, family history, and dyslipidaemia slightly improved the C-statistic to 0.88 (0.86-0.90) (P for difference between models <0.0001). Quartiles of probability of CAD from the clinical prediction model provided good diagnostic and prognostic stratification: in the lowest quartiles there were no cases of obstructive CAD and cumulative risk of the composite endpoint was less than 3% at 2 years. CONCLUSION: The pre-test probability model recommended in current ESC guidelines substantially overestimates likelihood of CAD when applied to a contemporary, unselected, all-comer population. We provide an updated prediction model that identifies subgroups with low likelihood of obstructive CAD and good prognosis in which non-invasive testing may safely be deferred.

Pentadiynylidene and Its Methyl-Substituted Derivates: Threshold Photoelectron Spectroscopy of R1-C5-R2 Triplet Carbon Chains.

Mass-selective threshold photoelectron spectroscopy in the gas phase was employed to characterize the dialkynyl triplet carbenes pentadiynylidene (HC5H), methylpentadiynylidene (MeC5H), and dimethylpentadiynylidene (MeC5Me). Diazo compounds were employed as precursors to generate the carbenes by flash pyrolysis. The R1-C5-R2 carbon chains were photoionized by vacuum ultraviolet (VUV) synchrotron radiation in photoelectron photoion coincidence (PEPICO) experiments. High-level ab initio computations were carried out to support the interpretation of the experiments. For the unsubstituted pentadiynylidene (R1 = R2 = H) the recorded spectrum yields an adiabatic ionization energy (IEad) of 8.36 ± 0.03 eV. In addition, a second carbene isomer, 3-(didehydrovinylidene)cyclopropene, with a singlet electronic ground state, was identified in the spectrum based on the IEad of 8.60 ± 0.03 eV and Franck-Condon simulations. We found that multireference computations are required to reliably calculate the IEad for this molecule. CASPT2 computations predicted an IEad = 8.55 eV, while coupled-cluster computations significantly overestimate the IE. The cyclic isomer is most likely formed from another isomer of the precursor present in the sample. Stepwise methyl-substitution of the carbene leads to a reduction of the IE to 7.77 ± 0.04 eV for methylpentadiynylidene and 7.27 ± 0.06 eV for dimethylpentadiynylidene. The photoionization and dissociative photoionization of the precursors is investigated as well.

A pan-Canadian measure of active living environments using open data.

BACKGROUND: Neighbourhood environments that support active living, such as walking or cycling for transportation, may decrease the burden of chronic conditions related to sedentary behaviour. Many measures exist to summarize features of communities that support active living, but few are pan-Canadian and none use open data sources that can be widely shared. This study reports the development and validation of a novel set of indicators of active living environments using open data that can be linked to national health surveys and can be used by local, regional or national governments for public health surveillance. DATA AND METHODS: A Geographic Information System (GIS) was used to calculate a variety of measures of the connectivity, density and proximity to destinations for 56,589 dissemination areas (DAs) across Canada (2016 data). Pearson correlation coefficients were calculated to assess the association between each measure and the rates of walking to work and taking active transportation to work (a combination of walking, cycling and using public transportation) from census data. The active living environment measures selected for the final database were used to classify the DAs by the favourability of their active living environment into groups by k-medians clustering. RESULTS: All measures were correlated with walking-to-work and active-transportation-to-work rates at the DA level, whether they were derived using proprietary or open data sources. Coverage of open data was consistent across Canadian regions. Three measures were selected for the Canadian Active Living Environments (Can-ALE) dataset based on the correlation analysis, but also on the principles of suitability for a variety of community sizes and openly available data: (1) three-way intersection density of roads and footpaths derived from OpenStreetMap (OSM), (2) weighted dwelling density derived from Statistics Canada dwelling counts and (3) points of interest derived from OSM. A measure of access to public transportation was added for the subset of DAs in larger urban areas and was strongly related to active-transportation-to-work rates. Active-transportation-to-work rates were graded, in steps, by the five Can-ALE groups derived from the cluster analysis, although walking-to-work rates exceeded the national average only in the most favourable active living environments. DISCUSSION: Open data may be used to derive measures that characterize the active living environments of Canadian communities.

Peripheral Endothelial Function and Coronary Flow Velocity Reserve Are Not Associated in Women with Angina and No Obstructive Coronary Artery Disease: The iPOWER Study.

PURPOSE: We investigated whether impaired flow-mediated dilation (FMD) and plasma biomarkers reflecting endothelial dysfunction are associated with coronary microvascular dysfunction (CMD) in women with angina and no obstructive coronary artery disease (CAD). METHODS: Patients (n = 194) were randomly selected women with angina pectoris and no obstructive CAD (<50% stenosis). A reference population of asymptomatic women without CAD (n = 25) was included. We measured FMD in the brachial artery by high-resolution ultrasound. Coronary flow velocity reserve (CFVR) was assessed by transthoracic Doppler flow echocardiography (TTDE) of the left anterior descending artery during rest and high-dose dipyridamole infusion. CMD was defined as CFVR <2. RESULTS: FMD and CFVR were measured in 128 patients and 21 controls. Mean (SD) age was 64.5 (8.9) years, mean CFVR was 2.3 (2.0-2.7), and mean FMD was 8.4% (4.8%) in angina patients. Angina patients had a higher risk factor burden compared with the reference population. Measures of peripheral endothelial dysfunction and endothelial plasma biomarkers did not differ according to angina or CFVR. CFVR and FMD did not correlate (Spearman ρ = -0.07, p = 0.45). CONCLUSIONS: FMD and biomarkers of endothelial dysfunction did not identify individuals with CMD assessed as impaired CFVR by TTDE in women with angina and no obstructive CAD.

Functional conservation despite structural divergence in ligand-responsive RNA switches.

An internal ribosome entry site (IRES) initiates protein synthesis in RNA viruses, including the hepatitis C virus (HCV). We have discovered ligand-responsive conformational switches in viral IRES elements. Modular RNA motifs of greatly distinct sequence and local secondary structure have been found to serve as functionally conserved switches involved in viral IRES-driven translation and may be captured by identical cognate ligands. The RNA motifs described here constitute a new paradigm for ligand-captured switches that differ from metabolite-sensing riboswitches with regard to their small size, as well as the intrinsic stability and structural definition of the constitutive conformational states. These viral RNA modules represent the simplest form of ligand-responsive mechanical switches in nucleic acids.

Structure of the Ribosomal RNA Decoding Site Containing a Selenium-Modified Responsive Fluorescent Ribonucleoside Probe.

Comprehensive understanding of the structure-function relationship of RNA both in real time and at atomic level will have a profound impact in advancing our understanding of RNA functions in biology. Here, we describe the first example of a multifunctional nucleoside probe, containing a conformation-sensitive fluorophore and an anomalous X-ray diffraction label (5-selenophene uracil), which enables the correlation of RNA conformation and recognition under equilibrium and in 3D. The probe incorporated into the bacterial ribosomal RNA decoding site, fluorescently reports antibiotic binding and provides diffraction information in determining the structure without distorting native RNA fold. Further, by comparing solution binding data and crystal structure, we gained insight on how the probe senses ligand-induced conformational change in RNA. Taken together, our nucleoside probe represents a new class of biophysical tool that would complement available tools for functional RNA investigations.

Correcting pervasive errors in RNA crystallography through enumerative structure prediction.

Three-dimensional RNA models fitted into crystallographic density maps exhibit pervasive conformational ambiguities, geometric errors and steric clashes. To address these problems, we present enumerative real-space refinement assisted by electron density under Rosetta (ERRASER), coupled to Python-based hierarchical environment for integrated 'xtallography' (PHENIX) diffraction-based refinement. On 24 data sets, ERRASER automatically corrects the majority of MolProbity-assessed errors, improves the average R(free) factor, resolves functionally important discrepancies in noncanonical structure and refines low-resolution models to better match higher-resolution models.

Conformational flexibility of viral RNA switches studied by FRET.

The function of RNA switches involved in the regulation of transcription and translation relies on their ability to adopt different, structurally well-defined states. A new class of ligand-responsive RNA switches, which we recently discovered in positive strand RNA viruses, are distinct from conventional riboswitches. The viral switches undergo large conformational changes in response to ligand binding while retaining the same secondary structure in their free and ligand-bound forms. Here, we describe FRET experiments to study folding and ligand binding of the viral RNA switches. In addition to reviewing previous approaches involving RNA model constructs which were directly conjugated with fluorescent dyes, we outline the design and application of new modular constructs for FRET experiments, in which dye labeling is achieved by hybridization of a core RNA switch module with universal DNA fluorescent probes. As an example, folding and ligand binding of the RNA switch from the internal ribosome entry site of hepatitis C virus is studied comparatively with conventional and modular FRET constructs.

Crystal-Structure-Guided Design of Self-Assembling RNA Nanotriangles.

RNA nanotechnology uses RNA structural motifs to build nanosized architectures that assemble through selective base-pair interactions. Herein, we report the crystal-structure-guided design of highly stable RNA nanotriangles that self-assemble cooperatively from short oligonucleotides. The crystal structure of an 81 nucleotide nanotriangle determined at 2.6 Šresolution reveals the so-far smallest circularly closed nanoobject made entirely of double-stranded RNA. The assembly of the nanotriangle architecture involved RNA corner motifs that were derived from ligand-responsive RNA switches, which offer the opportunity to control self-assembly and dissociation.

Single-Incision Transumbilical Surgery (SITUS) versus Single-Port Laparoscopic Surgery and conventional laparoscopic surgery: a prospective randomized comparative study of performance with novices in a dry laboratory.

PURPOSE: To evaluate the Single-Incision Transumbilical Surgery (SITUS) technique as compared to an established laparoendoscopic single-site surgery (LESS) technique (Single-Port Laparoscopic Surgery, SPLS) and conventional laparoscopy (CLS) in a surgical simulator model. METHODS: Sixty-three medical students without previous laparoscopic experience were randomly assigned to one of the three groups (SITUS, SPLS and CLS). Subjects were asked to perform five standardized tasks of increasing difficulty adopted from the Fundamentals of Laparoscopic Surgery curriculum. Statistical evaluation included task completion times and accuracy. RESULTS: Overall performances of all tasks (except precision cutting) were significantly faster and of higher accuracy in the CLS and SITUS groups than in the SPLS group (p = 0.004 to p < 0.001). CLS and SITUS groups alone showed no significant difference in performance times and accuracy measurements for all tasks (p = 0.048 to p = 0.989). CONCLUSIONS: SITUS proved to be a simple, but highly effective technique to overcome restrictions of SPLS. In a surgical simulator model, novices were able to achieve task performances comparable to CLS and did significantly better than using a port-assisted LESS technique such as SPLS. The demonstrated advantages of SITUS may be attributed to a preservation of the basic principles of conventional laparoscopy, such as the use of straight instruments and an adequate degree of triangulation.

Ligand-responsive RNA mechanical switches.

Ligand-responsive RNA mechanical switches represent a new class of simple switching modules that adopt well-defined ligand-free and bound conformational states, distinguishing them from metabolite-sensing riboswitches. Initially discovered in the internal ribosome entry site (IRES) of hepatitis C virus (HCV), these RNA switch motifs were found in the genome of diverse other viruses. Although large variations are seen in sequence and local secondary structure of the switches, their function in viral translation initiation that requires selective ligand recognition is conserved. We recently determined the crystal structure of an RNA switch from Seneca Valley virus (SVV) which is able to functionally replace the switch of HCV. The switches from both viruses recognize identical cognate ligands despite their sequence dissimilarity. Here, we describe the discovery of 7 new switches in addition to the previously established 5 examples. We highlight structural and functional features unique to this class of ligand-responsive RNA mechanical switches and discuss implications for therapeutic development and the construction of RNA nanostructures.

Structure of a hepatitis C virus RNA domain in complex with a translation inhibitor reveals a binding mode reminiscent of riboswitches.

The internal ribosome entry site (IRES) in the hepatitis C virus (HCV) RNA genome is essential for the initiation of viral protein synthesis. IRES domains adopt well-defined folds that are potential targets for antiviral translation inhibitors. We have determined the three-dimensional structure of the IRES subdomain IIa in complex with a benzimidazole translation inhibitor at 2.2 Å resolution. Comparison to the structure of the unbound RNA in conjunction with studies of inhibitor binding to the target in solution demonstrate that the RNA undergoes a dramatic ligand-induced conformational adaptation to form a deep pocket that resembles the substrate binding sites in riboswitches. The presence of a well-defined ligand-binding pocket within the highly conserved IRES subdomain IIa holds promise for the development of unique anti-HCV drugs with a high barrier to resistance.

RNA-Puzzles: a CASP-like evaluation of RNA three-dimensional structure prediction.

We report the results of a first, collective, blind experiment in RNA three-dimensional (3D) structure prediction, encompassing three prediction puzzles. The goals are to assess the leading edge of RNA structure prediction techniques; compare existing methods and tools; and evaluate their relative strengths, weaknesses, and limitations in terms of sequence length and structural complexity. The results should give potential users insight into the suitability of available methods for different applications and facilitate efforts in the RNA structure prediction community in ongoing efforts to improve prediction tools. We also report the creation of an automated evaluation pipeline to facilitate the analysis of future RNA structure prediction exercises.