Interplatform comparison between three ion mobility techniques for human plasma lipid collision cross sections

The implementation of ion mobility spectrometry (IMS) in liquid chromatography-high-resolution mass spectrometry (LC-HRMS) workflows has become a valuable tool for improving compound annotation in metabolomics analyses by increasing peak capacity and by adding a new molecular descriptor, the collision cross section (CCS). Although some studies reported high repeatability and reproducibility of CCS determination and only few studies reported good interplatform agreement for small molecules, standardized protocols are still missing due to the lack of reference CCS values and reference materials. We present a comparison of CCS values of approximatively one hundred lipid species either commercially available or extracted from human plasma. We used three different commercial ion mobility technologies from different laboratories, drift tube IMS (DTIMS), travelling wave IMS (TWIMS) and trapped IMS (TIMS), to evaluate both instrument repeatability and interlaboratory reproducibility. We showed that CCS discrepancies of 0.3% (average) could occur depending on the data processing software tools. Moreover, eleven CCS calibrants were evaluated yielding mean RSD below 2% for eight calibrants, ESI Low concentration tuning mix (Tune Mix) showing the lowest RSD (< 0.5%) in both ion modes. Tune Mix calibrated CCS from the three different IMS instruments proved to be well correlated and highly reproducible (R2 > 0.995 and mean RSD ≤ 1%). More than 90% of the lipid CCS had deviations of less than 1%, demonstrating high comparability between techniques, and the possibility to use the CCS as molecular descriptor. We highlighted the need of standardized procedures for calibration, data acquisition, and data processing. This work demonstrates that using harmonized analytical conditions are required for interplatform reproducibility for CCS determination of human plasma lipids.

Bedside preoperative predictors of difficult laryngeal exposure in microlaryngeal surgery

PURPOSE

Successful microlaryngeal surgery relies on an adequate laryngeal exposure. Recognizing the likelihood of challenging exposure prior to microlaryngeal surgery may assist in selecting the appropriate surgical approach and even prompt consideration of alternative treatment options. We aim to apply the mini-Laryngoscore, a preoperative assessment tool, to our study population and incorporate novel variables to optimize the prediction model.

METHODS

This single-center prospective cohort study included 80 consecutive patients undergoing elective microlaryngeal surgery, from January 1, to June 30, 2023. Each patient underwent a presurgical evaluation of 15 parameters and an intraoperative scoring of the anterior commissure visualization. These parameters were assessed for their association with difficult laryngeal exposure, using multiple logistic regression analysis. We created a novel prediction model for DLE and compared it with the existing model, the mini-Laryngoscore.

RESULTS

Out of 80 patients, 24 (30%) patients had difficult laryngeal exposure, including 3 cases (3.8%) in which visualization of the anterior commissure was not possible. A large neck diameter (OR, 1.4; CI 1.1-1.9) and the presence of upper teeth (OR, 8.9; CI 1.3-62.8) were independent risk factors for a difficult laryngeal exposure, while a larger interincisors gap was the only independent protector factor (OR, 0.3; CI 0.1-0.8). The logistic regression model combining these three independent risk factors displayed a high discriminative value AUC = 0.89 (CI 0.81-0.97). The predictive performance of the mini-Laryngoscore was 0.73 (CI 0.62-0.85).

CONCLUSION

Combining two parameters from the mini-Laryngoscore (upper jaw dental state and interincisors gap distance) with neck circumference measurement can accurately predict the risk of difficult laryngeal exposure.

Innovative direct introduction-ion mobility-mass spectrometry (DI-IM-MS) approach for fast and robust isomer-specific quantification in a complex matrix: Application to 2'-fucosyllactose (2'-FL) in breast milk

Identification and specific quantification of isomers in a complex biological matrix by mass spectrometry alone is not an easy task due to their identical chemical formula and therefore their same mass-to-charge ratio (m/z). Here, the potential of direct introduction combined with ion mobility-mass spectrometry (DI-IM-MS) for rapid quantification of isomers as human milk oligosaccharides (HMOs) was investigated. Differences in HMO profiles between various analyzed breast milk samples were highlighted using the single ion mobility monitoring (SIM2) acquisition for high ion mobility resolution detection. Furthermore, the Se+ (secretor) or Se- (non-secretor) phenotype could be assigned to breast milk samples studied based on their HMO contents, especially on the response of 2'-fucosyllactose (2'-FL) and lacto-N-fucopentaose I (LNFP I). The possibility of quantifying a specific isomer in breast milk by DI-IM-MS was also investigated. The standard addition method allowed the determination of the 2'-FL despite the presence of other oligosaccharides, including 3-fucosyllactose (3-FL) isomer in breast milk. This proof-of-concept study demonstrated the high potential of such an approach for the rapid and convenient quantification of isomers in complex mixtures.

Energy Resolved Mass Spectrometry for Interoperable Non-resonant Collisional Spectra in Metabolomics

In untargeted metabolomics, the unambiguous identification of metabolites remains a major challenge. This requires high-quality spectral libraries for reliable metabolite identification, which is essential for translating metabolomics data into meaningful biological information. Several attempts have been made to generate reproducible product ion spectra (PIS) under a low collision energy (ELab) regime and nonresonant collisional conditions but have not fully succeeded. We examined the ERMS (energy-resolved mass spectrometry) breakdown curves of two lipo-amino acids and showed the possibility to highlight "singular points", called descriptors hereafter (linked to respective ELab depending on the instrument), for each of the monomodal product ion profiles. Using several instruments based on different technologies, the PIS recorded at these specific ELab sites shows remarkable similarities. The descriptors appeared as being independent of the fragmentation mechanisms and can be used to overcome the main instrumental effects that limit the interoperability of spectral libraries. This proof-of-concept study, performed on two particular lipo-amino acids, demonstrates the high potential of ERMS-derived information to determine the instrument-specific ELab at which PIS recorded in nonresonant conditions become highly similar and instrument-independent, thus comparable across platforms. This innovative but straightforward approach could help remove some of the obstacles to metabolite identification in nontargeted metabolomics, putting an end to a challenging chimera.

Exploring the role of ChatGPT in clinical decision-making in otorhinolaryngology: a ChatGPT designed study

PURPOSE

Since the beginning of 2023, ChatGPT emerged as a hot topic in healthcare research. The potential to be a valuable tool in clinical practice is compelling, particularly in improving clinical decision support by helping physicians to make clinical decisions based on the best medical knowledge available. We aim to investigate ChatGPT's ability to identify, diagnose and manage patients with otorhinolaryngology-related symptoms.

METHODS

A prospective, cross-sectional study was designed based on an idea suggested by ChatGPT to assess the level of agreement between ChatGPT and five otorhinolaryngologists (ENTs) in 20 reality-inspired clinical cases. The clinical cases were presented to the chatbot on two different occasions (ChatGPT-1 and ChatGPT-2) to assess its temporal stability.

RESULTS

The mean score of ChatGPT-1 was 4.4 (SD 1.2; min 1, max 5) and of ChatGPT-2 was 4.15 (SD 1.3; min 1, max 5), while the ENTs mean score was 4.91 (SD 0.3; min 3, max 5). The Mann-Whitney U test revealed a statistically significant difference (p < 0.001) between both ChatGPT's and the ENTs's score. ChatGPT-1 and ChatGPT-2 gave different answers in five occasions.

CONCLUSIONS

Artificial intelligence will be an important instrument in clinical decision-making in the near future and ChatGPT is the most promising chatbot so far. Despite needing further development to be used with safety, there is room for improvement and potential to aid otorhinolaryngology residents and specialists in making the most correct decision for the patient.

Very-early detection of atrial fibrillation after ablation evaluated by a wearable ECG-patch predicts late blanking period recurrence: Preliminary data from a prospective registry

Introduction

Atrial fibrillation (AF) ablation represents a safe and effective procedure to restore sinus rhythm. The idea that post-procedural AF episodes - during the blanking period - are not considered treatment failure has been increasingly challenged. The E-Patch, a single-use adhesive electrode, facilitates extended continuous ECG monitoring for 120 h. This pilot study aims to assess the effectiveness of this ambulatory monitoring device and investigate whether very-early AF recurrence correlates with delayed blanking period ablation outcomes.

Methods

We conducted a single-center, prospective, longitudinal study, including consecutive post-ablation patients monitored with the E-patch. The ability of the device to continuously record was analyzed, as well as the occurrence of AF episodes during external 7-day loop-recorder in the 2nd-month post-ablation.

Results

We included 40 patients, median age 62 years (IQR 56-70). E-Patch monitoring was obtained for a median of 118 h (IQR 112-120), with no discomfort nor interpretation artefacts. Very-early AF recurrence was detected in 11 (27.5 %) patients, with a median AF burden of 7 % (IQR 6 %-33 %). Late-blanking period AF was detected in 13 (33 %) of the external 7-day loop recordings. Of the 11 patients that had very-early AF recurrence, 10 (91 %) had late-blanking AF. Very-early AF detection showed 77 % (95 % CI 64 %-90 %) sensitivity and 96 % (95 % CI 90-100 %) specificity in predicting late-blanking AF, with a non-parametric ROC curve AUC of 0.903 (95 % 0.797--1.0).

Conclusion

The E-Patch was able to detect very-early AF during an extended period. Very-early AF detection emerges as a predictor of AF recurrence during the late blanking period post-ablation.

Enantioselective Reduction of Noncovalent Complexes of Amino Acids with CuII via Resonant Collision-Induced Dissociation: Collision Energy, Activation Duration Effects, and RRKM Modeling

Formation of noncovalent complexes is one of the approaches to perform chiral analysis with mass spectrometry. Enantiomeric distinction of amino acids (AAs) based on the relative rate constants of competitive fragmentations of quaternary copper complexes is an efficient method for chiral differentiation. Here, we studied the complex [CuII,(Phe,PhG,Pro-H)]+ (m/z 493) under resonant collision-induced dissociation conditions while varying the activation time. The precursor ion can yield two main fragments through the loss of the non-natural AA phenylglycine (PhG): the expected product ion [CuII,(Phe,Pro-H)]+ (m/z 342) and the reduced product ion [CuI,(Phe,Pro)]+ (m/z 343). Enantioselective reduction describes the difference in relative abundance of these ions, which depends on the chirality of the precursor ion: the formation of the reduced ion m/z 343 is favored in homochiral complexes (DDD) compared to heterochiral complexes (such as LDD). Energy-resolved mass spectrometry data show that reduction, which arises from rearrangement, is favored at a low collision energy (CE) and long activation time (ActT), whereas direct cleavage preferentially occurs at a high CE and short ActT. These results were confirmed with kinetic modeling based on RRKM theory. For this modeling, it was necessary to set a pre-exponential factor as a reference, so that the E0 values obtained are relative values. Interestingly, these simulations showed that the critical energy E0 required to form the reduced ion is comparable in both homochiral and heterochiral complexes. However, the formation of product ion m/z 342 through direct cleavage is associated with a lower E0 in heterochiral complexes. Consequently, enantioselectivity would not be caused by enhanced reduction in homochiral complexes but rather by direct cleavage being favored in heterochiral complexes.

A combined experimental-molecular modeling study of crown ether europium complexes: Effects of the coordinated anion on structural and luminescence properties

It is reported the synthesis, characterization by elemental analysis, thermogravimetry; electronic absorption, infrared, excitation, and emission spectroscopies of the [Eu(12C4)(phen)2(X)n]X2 complexes, where 12C4 = 12-crown-4, phen = 1,10-phenanthroline, and X  = F-, Cl-, Br-, SCN-, ClO4-, and NO3-. It is verified that the polarizability of the anion X- exerts remarkable effects on the emission process. As a general trend, lower wavenumbers for the 7F0→5L6, 7F0→5D2 and 7F0→5D1 transitions are associated with the anions with higher volumes and, consequently, higher polarizability. The molecular modeling results performed with quantum methods (RHF and DFT) suggest some relationships between the calculated structures, electronic, and luminescence properties with the presence of the LMCT (ligand-to-metal charge transfer) states, which explains the differences in the emission spectra of these complexes due to the coordinated anion.

Influence of the addition of nanohydroxyapatite to scaffolds on proliferation and differentiation of human mesenchymal stem cells: a systematic review of in vitro studies

One of the main challenges of tissue engineering in dentistry is to replace bone and dental tissues with strategies or techniques that simulate physiological tissue repair conditions. This systematic review of in vitro studies aimed to evaluate the influence of the addition of nanohydroxyapatite (NHap) to scaffolds on cell proliferation and osteogenic and odontogenic differentiation of human mesenchymal stem cells. In vitro studies on human stem cells that proliferated and differentiated into odontogenic and osteogenic cells in scaffolds containing NHap were included in this study. Searches in PubMed/MEDLINE, Scopus, Web of Science, OpenGrey, ProQuest, and Cochrane Library electronic databases were performed. The total of 333 articles was found across all databases. After reading and analyzing titles and abstracts, 8 articles were selected for full reading and extraction of qualitative data. Results showed that despite the large variability in scaffold composition, NHap-containing scaffolds promoted high rates of cell proliferation, increased alkaline phosphatase (ALP) activity during short culture periods, and induced differentiation, as evidenced by the high expression of genes involved in osteogenesis and odontogenesis. However, further studies with greater standardization regarding NHap concentration, type of scaffolds, and evaluation period are needed to observe possible interference of these criteria in the action of NHap on the proliferation and differentiation of human stem cells.

Help Comes from Unexpected Places: How a Tiny Fairy and a Tropical Fish may help us Model Mucopolysaccharidoses

INTRODUCTION

When it comes to disease modeling, countless models are available for Lysosomal Storage Diseases (LSD). Historically, two major approaches are well-established: in vitro assessments are performed in patient fibroblasts, while in vivo pre-clinical studies are performed in mouse models. Still, both platforms have a series of drawbacks. Thus, we implemented two alternative and innovative protocols to mimic a particular sub-group of LSDs, the Mucopolysaccharidoses both in vitro and in vivo.

METHODS

The first one relies on a non-invasive approach using dental pulp stem cells from deciduous teeth (SHEDs). SHEDs are multipotent neuronal precursors that can easily be collected. The second uses a state-of-the-art gene editing technology (CRISPR/Cas9) to generate zebrafish disease models.

RESULTS

Even though this is an ongoing project, we have already established and characterized two MPS II and one MPS VI SHED cell models. These cells self-maintain through several passages and can give rise to a variety of cells including neurons. Furthermore, all MPS-associated sub-cellular phenotypes we have assessed so far are easily observable in these cells. Regarding our zebrafish models, we have successfully knocked down both naglu and hgsnat and the first results we got from the behavioral analysis are promising ones, as we can observe altered activity and sleep patterns in the genetically modified fish. For this particular approach we chose MPS III forms as our target disorders, since their neurological features (hyperactivity, seizures and motor impairment) and lifespan decrease would be easily recognizable in zebrafish.

CONCLUSION

Now that these methods are well-established in our lab, their potential is immense. On one hand, the newly developed models will be of ultimate value to understand the mechanisms underlying MPS sub-cellular pathology, which have to be further elucidated. On the other hand, they will constitute an optimal platform for drug testing in house. Also noteworthy, our models will be published as lab resources and made available for the whole LSD community.

Challenges in the Definitive Diagnosis of Niemann-Pick Type C-Leaky Variants and Alternative Transcripts

Niemann-Pick type C (NPC, ORPHA: 646) is a neuro-visceral, psychiatric disease caused predominantly by pathogenic variants in the NPC1 gene or seldom in NPC2. The rarity of the disease, and its wide range of clinical phenotypes and ages of onset, turn the diagnosis into a significant challenge. Other than the detailed clinical history, the typical diagnostic work-up for NPC includes the quantification of pathognomonic metabolites. However, the molecular basis diagnosis is still of utmost importance to fully characterize the disorder. Here, the authors provide an overview of splicing variants in the NPC1 and NPC2 genes and propose a new workflow for NPC diagnosis. Splicing variants cover a significant part of the disease-causing variants in NPC. The authors used cDNA analysis to study the impact of such variants, including the collection of data to classify them as leaky or non-leaky pathogenic variants. However, the presence of naturally occurring spliced transcripts can misdiagnose or mask a pathogenic variant and make the analysis even more difficult. Analysis of the NPC1 cDNA in NPC patients in parallel with controls is vital to assess and detect alternatively spliced forms. Moreover, nonsense-mediated mRNA decay (NMD) analysis plays an essential role in evaluating the naturally occurring transcripts during cDNA analysis and distinguishing them from other pathogenic variants' associated transcripts.

Development of Engineered-U1 snRNA Therapies: Current Status

Splicing of pre-mRNA is a crucial regulatory stage in the pathway of gene expression. The majority of human genes that encode proteins undergo alternative pre-mRNA splicing and mutations that affect splicing are more prevalent than previously thought. Targeting aberrant RNA(s) may thus provide an opportunity to correct faulty splicing and potentially treat numerous genetic disorders. To that purpose, the use of engineered U1 snRNA (either modified U1 snRNAs or exon-specific U1s-ExSpeU1s) has been applied as a potentially therapeutic strategy to correct splicing mutations, particularly those affecting the 5' splice-site (5'ss). Here we review and summarize a vast panoply of studies that used either modified U1 snRNAs or ExSpeU1s to mediate gene therapeutic correction of splicing defects underlying a considerable number of genetic diseases. We also focus on the pre-clinical validation of these therapeutic approaches both in vitro and in vivo, and summarize the main obstacles that need to be overcome to allow for their successful translation to clinic practice in the future.

MicroRNA Profile, Putative Diagnostic Biomarkers and RNA-Based Therapies in the Inherited Lipid Storage Disease Niemann-Pick Type C

Lipids are essential for cellular function and are tightly controlled at the transcriptional and post-transcriptional levels. Dysregulation of these pathways is associated with vascular diseases, diabetes, cancer, and several inherited metabolic disorders. MicroRNAs (miRNAs), in particular, are a family of post-transcriptional gene repressors associated with the regulation of many genes that encode proteins involved in multiple lipid metabolism pathways, thereby influencing their homeostasis. Thus, this class of non-coding RNAs (ncRNAs) has emerged as a promising therapeutic target for the treatment of lipid-related metabolic alterations. Most of these miRNAs act at an intracellular level, but in the past few years, a role for miRNAs as intercellular signaling molecules has also been uncovered since they can be transported in bodily fluids and used as potential biomarkers of lipid metabolic alterations. In this review, we point out the current knowledge on the miRNA signature in a lysosomal storage disorder associated with lipid dysfunction, Niemann-Pick type C, and discuss the potential use of miRNAs as biomarkers and therapeutic targets for RNA-based therapies.

Chemical Exposure Highlighted without Any A Priori Information in an Epidemiological Study by Metabolomic FT-ICR-MS Fingerprinting at High Throughput and High Resolution

Epidemiological studies aim to assess associations between diseases and risk factors. Such investigations involve a large sample size and require powerful analytical methods to measure the effects of risk factors, resulting in a long analysis time. In this study, chemical exposure markers were detected as the main variables strongly affecting two components coming from a principal component analysis (PCA) exploration of the metabolomic data generated from urinary samples collected on a cohort of about 500 individuals using direct introduction coupled with a Fourier-transform ion cyclotron resonance instrument. The assignment of their chemical identity was first achieved based on their isotopic fine structures detected at very high resolution (Rp > 900,000). Their identification as dimethylbiguanide and sotalol was obtained at level 1, thanks to the available authentic chemical standards, tandem mass spectrometry (MS/MS) experiments, and collision cross section measurements. Epidemiological data confirmed that the subjects discriminated by PCA had declared to be prescribed these drugs for either type II diabetes or cardiac arrhythmia. Concentrations of these drugs in urine samples of interest were also estimated by rapid quantification using an external standard calibration method, direct introduction, and MS/MS experiments. Regression analyses showed a good correlation between the estimated drug concentrations and the scores of individuals distributed on these specific PCs. The detection of these chemical exposure markers proved the potential of the proposed high-throughput approach without any prior drug exposure knowledge as a powerful emerging tool for rapid and large-scale phenotyping of subjects enrolled in epidemiological studies to rapidly characterize the chemical exposome and adherence to medical prescriptions.

Leukocyte Imbalances in Mucopolysaccharidoses Patients

Mucopolysaccharidoses (MPSs) are rare inherited lysosomal storage diseases (LSDs) caused by deficient activity in one of the enzymes responsible for glycosaminoglycans lysosomal degradation. MPS II is caused by pathogenic mutations in the IDS gene, leading to deficient activity of the enzyme iduronate-2-sulfatase, which causes dermatan and heparan sulfate storage in the lysosomes. In MPS VI, there is dermatan sulfate lysosomal accumulation due to pathogenic mutations in the ARSB gene, leading to arylsulfatase B deficiency. Alterations in the immune system of MPS mouse models have already been described, but data concerning MPSs patients is still scarce. Herein, we study different leukocyte populations in MPS II and VI disease patients. MPS VI, but not MPS II patients, have a decrease percentage of natural killer (NK) cells and monocytes when compared with controls. No alterations were identified in the percentage of T, invariant NKT, and B cells in both groups of MPS disease patients. However, we discovered alterations in the naïve versus memory status of both helper and cytotoxic T cells in MPS VI disease patients compared to control group. Indeed, MPS VI disease patients have a higher frequency of naïve T cells and, consequently, lower memory T cell frequency than control subjects. Altogether, these results reveal MPS VI disease-specific alterations in some leukocyte populations, suggesting that the type of substrate accumulated and/or enzyme deficiency in the lysosome may have a particular effect on the normal cellular composition of the immune system.

Neurological Disease Modeling Using Pluripotent and Multipotent Stem Cells: A Key Step towards Understanding and Treating Mucopolysaccharidoses

Despite extensive research, the links between the accumulation of glycosaminoglycans (GAGs) and the clinical features seen in patients suffering from various forms of mucopolysaccharidoses (MPSs) have yet to be further elucidated. This is particularly true for the neuropathology of these disorders; the neurological symptoms are currently incurable, even in the cases where a disease-specific therapeutic approach does exist. One of the best ways to get insights on the molecular mechanisms driving that pathogenesis is the analysis of patient-derived cells. Yet, not every patient-derived cell recapitulates relevant disease features. For the neuronopathic forms of MPSs, for example, this is particularly evident because of the obvious inability to access live neurons. This scenario changed significantly with the advent of induced pluripotent stem cell (iPSC) technologies. From then on, a series of differentiation protocols to generate neurons from iPSC was developed and extensively used for disease modeling. Currently, human iPSC and iPSC-derived cell models have been generated for several MPSs and numerous lessons were learnt from their analysis. Here we review most of those studies, not only listing the currently available MPS iPSC lines and their derived models, but also summarizing how they were generated and the major information different groups have gathered from their analyses. Finally, and taking into account that iPSC generation is a laborious/expensive protocol that holds significant limitations, we also hypothesize on a tempting alternative to establish MPS patient-derived neuronal cells in a much more expedite way, by taking advantage of the existence of a population of multipotent stem cells in human dental pulp to establish mixed neuronal and glial cultures.

Molecular profile and peripheral markers of neurodegeneration in patients with Niemann-Pick type C: Decrease in Plasminogen Activator Inhibitor type 1 and Platelet-Derived Growth Factor type AA

Niemann-Pick type C1 (NPC1) is a fatal inherited disease, caused by pathogenic variants in NPC1 gene, which leads to intracellular accumulation of non-esterified cholesterol and glycosphingolipids. This accumulation leads to a wide range of clinical manifestations, including neurological and cognitive impairment as well as psychiatric disorders. The pathophysiology of cerebral damage involves loss of Purkinje cells, synaptic disturbance, and demyelination. Miglustat, a reversible inhibitor of glucosylceramide synthase, is an approved treatment for NPC1 and can slow neurological damage. The aim of this study was to assess the levels of peripheric neurodegeneration biomarkers of NPC1 patients, namely brain-derived neurotrophic factor (BDNF), platelet-derived growth factors (PDGF-AA and PDGF-AB/BB), neural cell adhesion molecule (NCAM), PAI-1 Total and Cathepsin-D, as well as the levels of cholestane-3β,5α,6β-triol (3β,5α,6β-triol), a biomarker for NPC1. Molecular analysis of the NPC1 patients under study was performed by next generation sequencing (NGS) in cultured fibroblasts. We observed that NPC1 patients treated with miglustat have a significant decrease in PAI-1 total and PDGF-AA concentrations, and no alteration in BDNF, NCAM, PDGF-AB/BB and Cathepsin D. We also found that NPC1 patients treated with miglustat have normalized levels of 3β,5α,6β-triol. The molecular analysis showed four described mutations, and for two patients was not possible to identify the second mutated allele. Our results indicate that the decrease of PAI-1 and PDGF-AA in NPC1 patients could be involved in the pathophysiology of this disease. This is the first work to analyze those plasmatic markers of neurodegenerative processes in NPC1 patients.

Cultural and Linguistic Adaptation of the Fall Risk Questionnaire-Portuguese Version

Falls are a major problem among older adults worldwide. Early detection of risk factors is important to decrease the burden of falls. The “Fall Risk Questionnaire” (FRQ) is a screening tool used to assess personal fall risk awareness in older populations, and it is also used as a behavior change tool. The aim of the present study was to undertake a cultural and linguistic adaptation of the FRQ to allow its use in the Portuguese population. To achieve this, we used the sequential method proposed by Beaton and colleagues. Statistical analysis was conducted by computing the intraclass correlation coefficient and Cronbach’s alpha score for intra-observer reliability. The panel revision demonstrated high concordance for all assessed items. The pretesting results indicated that, in general, the FRQ—Portuguese Version (FRQ-VP) was well accepted, and all items were adequate and easy to comprehend. The ICC and Cronbach’s alpha scores indicated high consistency between assessments (p < 0.01; alfa = 0.992). The FRQ-VP seemed to have good reliability and internal consistency. Because the definition of a fall experience may not be clear to the older population, a careful explanation of this item can lead to a better score computation.

Rapid structural characterization of human milk oligosaccharides and distinction of their isomers using trapped ion mobility spectrometry time-of-flight mass spectrometry

Oligosaccharides have multiple functions essential for health. Derived from the condensation of two to several monosaccharides, they are structurally diverse with many co-occurring structural isomer families, which make their characterization difficult. Thanks to its ability to separate small molecules based on their mass, size, shape, and charge, ion mobility-mass spectrometry (IM-MS) has emerged as a powerful tool for separating glycan isomers. Here, the potential of such a technique for the rapid characterization of main human milk oligosaccharides (HMOs) was investigated. Our study focused on 18 HMO standards. The IM-MS analysis enabled to distinguish almost all the HMOs studied, in particular thanks to the single ion mobility monitoring acquisition using the trapped ion mobility spectrometry device, providing high ion mobility resolution and enhanced ion mobility separation. Alternatively, the combination of IM-MS separation with MS/MS experiments has proven to increase performance in identifying HMOs and especially isomers poorly separated by ion mobility alone. Finally, collision cross-section values are provided for each species generated from the 18 HMOs standards, which can serve as an additional identifier to characterize HMOs.

Different ion mobility-mass spectrometry coupling techniques to promote metabolomics

Metabolomics has become increasingly popular in recent years for many applications ranging from clinical diagnosis, human health to biotechnological questioning. Despite technological advances, metabolomic studies are still currently limited by the difficulty of identifying all metabolites, a class of compounds with great chemical diversity. Although lengthy chromatographic analyses are often used to obtain comprehensive data, many isobar and isomer metabolites still remain unresolved, which is a critical point for the compound identification. Currently, ion mobility spectrometry is being explored in metabolomics as a way to improve metabolome coverage, analysis throughput and isomer separation. In this review, all the steps of a typical workflow for untargeted metabolomics are discussed considering the use of an ion mobility instrument. An overview of metabolomics is first presented followed by a brief description of ion mobility instrumentation. The ion mobility potential for complex mixture analysis is discussed regarding its coupling with a mass spectrometer alone, providing gas-phase separation before mass analysis as well as its combination with different separation platforms (conventional hyphenation but also multidimensional ion mobility couplings), offering multidimensional separation. Various instrumental and analytical conditions for improving the ion mobility separation are also described. Finally, data mining, including software packages and visualization approaches, as well as the construction of ion mobility databases for the metabolite identification are examined.

PeakForest: a multi-platform digital infrastructure for interoperable metabolite spectral data and metadata management

INTRODUCTION

Accuracy of feature annotation and metabolite identification in biological samples is a key element in metabolomics research. However, the annotation process is often hampered by the lack of spectral reference data in experimental conditions, as well as logistical difficulties in the spectral data management and exchange of annotations between laboratories.

OBJECTIVES

To design an open-source infrastructure allowing hosting both nuclear magnetic resonance (NMR) and mass spectra (MS), with an ergonomic Web interface and Web services to support metabolite annotation and laboratory data management.

METHODS

We developed the PeakForest infrastructure, an open-source Java tool with automatic programming interfaces that can be deployed locally to organize spectral data for metabolome annotation in laboratories. Standardized operating procedures and formats were included to ensure data quality and interoperability, in line with international recommendations and FAIR principles.

RESULTS

PeakForest is able to capture and store experimental spectral MS and NMR metadata as well as collect and display signal annotations. This modular system provides a structured database with inbuilt tools to curate information, browse and reuse spectral information in data treatment. PeakForest offers data formalization and centralization at the laboratory level, facilitating shared spectral data across laboratories and integration into public databases.

CONCLUSION

PeakForest is a comprehensive resource which addresses a technical bottleneck, namely large-scale spectral data annotation and metabolite identification for metabolomics laboratories with multiple instruments. PeakForest databases can be used in conjunction with bespoke data analysis pipelines in the Galaxy environment, offering the opportunity to meet the evolving needs of metabolomics research. Developed and tested by the French metabolomics community, PeakForest is freely-available at https://github.com/peakforest .

Evaluation of Memantine in AAV-AD Rat: A Model of Late-Onset Alzheimer's Disease Predementia

BACKGROUND

Though our understanding of Alzheimer's disease (AD) remains elusive, it is well known that the disease starts long before the first signs of dementia. This is supported by the large number of symptomatic drug failures in clinical trials and the increased trend to enroll patients at predementia stages with either mild or no cognitive symptoms. However, the design of pre-clinical studies does not follow this attitude, in particular regarding the choice of animal models, often irrelevant to mimic predementia Late Onset Alzheimer's Disease (LOAD).

OBJECTIVES

We aimed to pharmacologically validate the AAV-AD rat model to evaluate preventive treatment of AD.

METHODS

We evaluated an N-methyl-D-aspartate receptor antagonist, named memantine, in AAV-AD rats, an age-dependent amyloid rat model which closely mimics Alzheimer's pathology including asymptomatic and prodromal stages. Memantine was used at a clinically relevant dose (20 mg daily oral administration) from 4 (asymptomatic phase) to 10 (mild cognitive impairment phase) months of age.

RESULTS

A 6-month treatment with memantine promoted a non-amyloidogenic cleavage of APP followed by a decrease in soluble Aβ42. Consequently, both long-term potentiation and cognitive impairments were prevented. By contrast, the levels of hyperphosphorylated endogenous tau remained unchanged, indicating that a long-term memantine treatment is ineffective to restrain the APP processing-induced tauopathy.

CONCLUSIONS

Together, our data confirm that relevant models to LOAD, such as the AAV-AD rat, can provide a framework for a better understanding of the disease and accurate assessment of preventive treatments.

How to Design U1 snRNA Molecules for Splicing Rescue

Mutations affecting constitutive splice donor sites (5'ss) are among the most frequent genetic defects that disrupt the normal splicing process. Pre-mRNA splicing requires the correct identification of a number of cis-acting elements in an ordered fashion. By disrupting the complementarity of the 5'ss with the endogenous small nuclear RNA U1 (U1 snRNA), the key component of the spliceosomal U1 ribonucleoprotein, 5'ss mutations may result in exon skipping, intron retention or activation of cryptic splice sites. Engineered modification of the U1 snRNA seemed to be a logical method to overcome the effect of those mutations. In fact, over the last years, a number of in vitro studies on the use of those modified U1 snRNAs to correct a variety of splicing defects have demonstrated the feasibility of this approach. Furthermore, recent reports on its applicability in vivo are adding up to the principle that engineered modification of U1 snRNAs represents a valuable approach and prompting further studies to demonstrate the clinical translatability of this strategy.Here, we outline the design and generation of U1 snRNAs with different degrees of complementarity to mutated 5'ss. Using the HGSNAT gene as an example, we describe the methods for a proper evaluation of their efficacy in vitro, taking advantage of our experience to share a number of tips on how to design U1 snRNA molecules for splicing rescue.

Uma Emergência Rinológica: Pilha na Fossa Nasal

Os corpos estranhos nas fossas nasais são causas frequentes de recurso à urgência, sobretudo em idade pediátrica.Na maioria dos casos são inofensivos, podendo permanecer vários dias sem causar lesões. As pilhas sendo uma exceção,representam uma importante ameaça com necessidade de remoção urgente.Descreve-se o caso de uma criança com 4 anos de idade, observada no Serviço de Urgência com suspeita de corpoestranho na fossa nasal. Apresentava obstrução nasal e rinorreia unilateral sanguinolenta, com 5 horas de evolução.A radiografia dos ossos próprios nasais identificou um objeto redondo, radiopaco com sinal de duplo halo. Mediantea suspeita de uma pilha na fossa nasal, procedeu-se à sua imediata remoção sob anestesia geral.Pretendemos alertar para a perigosidade deste tipo de objeto, assim como para a necessidade de uma abordagemdiagnóstica e terapêutica céleres, a fim de evitar complicações graves.

Antimycobacterial compound of chitosan and ethambutol: ultrastructural biological evaluation in vitro against Mycobacterium tuberculosis

Chitosan (CS) is a promising biopolymer and has been tested as a complement to the action and compensation of toxicity presented by anti-tuberculosis drugs. The present work studied the adjuvant effect of CS with the drug ethambutol (EMB) as a compound (CS-EMB), to explore its antimicrobial and cytotoxic activity, using transmission electron microscopy (TEM), to examine ultracellular changes that represent possible antimycobacterial action of CS on Mycobacterium tuberculosis (Mtb). Antimycobacterial activities were tested against reference strains Mtb ATCC® H37Rv and multidrug resistant (MDR). In vitro cytotoxicity tests were performed on Raw 264.7. For the studied compounds, morphological, ultrastructural, and physical-chemical analyses were performed. Drug-polymer interactions that occur through the H bridges were confirmed by physical-chemical analyses. The CS-EMB compound is stable at pHs of 6.5-7.5, allowing its release at physiological pH. The antibacterial activity (minimum inhibitory concentration) of the CS-EMB compound was 50% greater than that of the EMB in the H37Rv and MDR strains and the ultrastructural changes in the bacilli observed by TEM proved that the CS-EMB compound has a bactericidal action, allowing it to break down the Mtb cell wall. The cytotoxicity of CS-EMB was higher than that of isolated EMB, IC50 279, and 176 μg/mL, respectively. It is concluded that CS-EMB forms a promising composite against strains Mtb H37Rv and multidrug resistant (MDR-TB).Key points• Our study will be the first to observe ultrastructurally the effects of the CS-EMB compound on Mtb cells.• CS-EMB antimicrobial activity in a multidrug-resistant clinical strain.• The CS-EMB compound has promising potential for the development of a new drug to fight tuberculosis.

First Direct Evidence of Interpartner Hydride/Deuteride Exchanges for Stored Sodiated Arginine/Fructose-6-phosphate Complex Anions within Salt-Solvated Structures

Mass spectrometric investigations of noncovalent binding between low molecular weight compounds revealed the existence of gas-phase (GP) noncovalent complex (NCC) ions involving zwitterionic structures. ESI MS is used to prove the formation of stable sodiated NCC anions between fructose (F6P) and arginine (R) moieties. Theoretical calculations indicate a folded solvated salt (i.e., sodiated carboxylate interacting with phosphate) rather than a charge-solvated form. Under standard CID conditions, [(F6P+R-H+Na)-H]^- competitively forms two major product ions (PIs) through partner splitting [(R-H+Na) loss] and charge-induced cross-ring cleavage while preserving the noncovalent interactions (noncovalent product ions (NCPIs)). MS/MS experiments combined with in-solution proton/deuteron exchanges (HDXs) demonstrated an unexpected labeling of PIs, i.e., a correlated D-enrichment/D-depletion. An increase in activation time up to 3000 ms favors such processes when limited to two H/D exchanges. These results are rationalized by interpartner hydride/deuteride exchanges (⟨HDX⟩) through stepwise isomerization/dissociation of sodiated NCC-d11 anions. In addition, the D-enrichment/D-depletion discrepancy is further explained by back HDX with residual water in LTQ (selective for the isotopologue NCPIs as shown by PI relaxation experiments). Each isotopologue leads to only one back HDX unlike multiple HDXs generally observed in GP. This behavior shows that NCPIs are zwitterions with charges solvated by a single water molecule, thus generating a back HDX through a relay mechanism, which quenches the charges and prevents further back HDX. By estimating back HDX impact on D-depletion, the interpartner ⟨HDX⟩ complementarity was thus illustrated. This is the first description of interpartner ⟨HDX⟩ and selective back HDX validating salt-solvated structures.

Delivery of oligonucleotide-based therapeutics: challenges and opportunities

Nucleic acid-based therapeutics that regulate gene expression have been developed towards clinical use at a steady pace for several decades, but in recent years the field has been accelerating. To date, there are 11 marketed products based on antisense oligonucleotides, aptamers and small interfering RNAs, and many others are in the pipeline for both academia and industry. A major technology trigger for this development has been progress in oligonucleotide chemistry to improve the drug properties and reduce cost of goods, but the main hurdle for the application to a wider range of disorders is delivery to target tissues. The adoption of delivery technologies, such as conjugates or nanoparticles, has been a game changer for many therapeutic indications, but many others are still awaiting their eureka moment. Here, we cover the variety of methods developed to deliver nucleic acid-based therapeutics across biological barriers and the model systems used to test them. We discuss important safety considerations and regulatory requirements for synthetic oligonucleotide chemistries and the hurdles for translating laboratory breakthroughs to the clinic. Recent advances in the delivery of nucleic acid-based therapeutics and in the development of model systems, as well as safety considerations and regulatory requirements for synthetic oligonucleotide chemistries are discussed in this review on oligonucleotide-based therapeutics.

Tuning Photoinduced Electron Transfer in POM-Bodipy Hybrids by Controlling the Environment: Experiment and Theory

The optical and electrochemical properties of a series of polyoxometalate (POM) oxoclusters decorated with two bodipy (boron-dipyrromethene) light-harvesting units were examined. Evaluated here in this polyanionic donor-acceptor system is the effect of the solvent and associated counterions on the intramolecular photoinduced electron transfer. The results show that both solvents and counterions have a major impact upon the energy of the charge-transfer state by modifying the solvation shell around the POMs. This modification leads to a significantly shorter charge separation time in the case of smaller counterion and slower charge recombination in a less polar solvent. These results were rationalized in terms of Marcus theory and show that solvent and counterion both affect the driving force for photoinduced electron transfer and the reorganization energy. This was corroborated with theoretical investigations combining DFT and molecular dynamics simulations.

Polarizability is a key parameter for molecular electronics

Identifying descriptors that govern charge transport in molecular electronics is of prime importance for the elaboration of devices. The effects of molecule characteristics, such as size, bulkiness or charge, have been widely reported. Herein, we show that the molecule polarizability can be a crucial parameter to consider. To this end, platinum nanoparticle self-assemblies (PtNP SAs) are synthesized in solution, including a series of polyoxometalates (POMs). The charge of the POM unit can be modified according to the nature of the central heteroatom while keeping its size constant. POM hybrids that display remote terminal thiol functions strongly anchor the PtNP surface to form robust SAs. IV curves, recorded by conductive AFM, show a decrease in Coulomb blockade as the dielectric constant of the POMs increases. In this system, charge transport across molecular junctions can be interpreted as variations in polarizability, which is directly related to the dielectric constant.

Acid-triggering of light-induced charge-separation in hybrid organic/inorganic molecular photoactive dyads for harnessing solar energy

H⁺ modulated charge-transfer in photoexcited covalently linked W and Mo Keggin-bodipy conjugates is demonstrated using transient absorption spectroscopy and photoluminescence. Adding acid switches on (W) or accelerates (Mo) charge separation.

An emerging powerful technique for distinguishing isomers: Trapped ion mobility spectrometry time-of-flight mass spectrometry for rapid characterization of estrogen isomers

RATIONALE

Isomer metabolites are involved in metabolic pathways, and their characterization is essential but remains challenging even using high-performance analytical platforms. The addition of ion mobility prior to mass analysis can help to separate isomers. Here, the ability of a recently developed trapped ion mobility spectrometry system to separate metabolite isomers was examined.

METHODS

Three pairs of estrogen isomers were studied as a model of isomeric metabolites under both negative and positive electrospray ionization (ESI) modes using a commercial trapped ion mobility spectrometry-TOF mass spectrometer. The standard metabolites were also spiked into human urine to evaluate the efficiency of trapped ion mobility spectrometry to separate isomers in complex mixtures.

RESULTS

The estradiol glucuronide isomers (E₂ β-3G and E₂ β-17G) could be distinguished as deprotonated species, while the estradiol epimers (E₂ β and E₂ α) and the methoxyestradiol isomers (2-MeO-E₂ β and 4-MeO-E₂ β) were separated as lithiated adducts in positive ionization mode. When performing analyses in the urine matrix, no alteration in the ion mobility resolving power was observed and the measured collision cross section (CCS) values varied by less than 1.0%.

CONCLUSIONS

The trapped ion mobility spectrometry-TOF mass spectrometer enabled the separation of the metabolite isomers with very small differences in CCS values (ΔCCS% = 2%). It is shown to be an effective tool for the rapid characterization of isomers in complex matrices.

Role of tilt-table testing in syncope diagnosis and management: analysis of patients referred to a syncope unit

Introduction

Head-up tilt-testing (HUT) enables the reproduction of reflex syncope in a laboratory setting. Despite being used to confirm the diagnosis of this syncope, there is some concerns regarding the best protocol to use and recent studies with implantable loop recorders have called the value of HUT into question.

Aim

To characterize the population undergoing HUT according to the modified Italian protocol, type of response to HUT and subsequent management at our center in the last 4 years.

Methods

Retrospective analysis of consecutive P who underwent HUT between 2015 and 2018. Descriptive analysis of patients (P) demographics and medical history, indication for HUT, type of response to HUT and management.

Results

A total of 419P (55.1% female) were included with a mean age of 62 years. The majority (n=302, 72.1%) had comorbidities (structural heart disease – 55%, cardiac dysrhythmias – 57.6%, hypertension – 48.3%, diabetes – 15.6%, depression – 15.9%, cerebrovascular disease –10.6%) or was under medication (n=220, 52.5%) with a potential hypotensive or bradycardic effect (44.1% ACEI/ARA, 29.1% beta-blocker, 27.7% diuretic, 23.6% antidepressant, 22.7% calcium channel blocker, 19.1% benzodiazepines). Syncope/presyncope episodes accounted for 56.1% of the HUT, with falls and disequilibrium accounting for 52%. In 21 cases (5%) suspected dysautonomia or other non-specified reasons were the indication for HUT. HUT were ordered according to the guidelines in 136P (84.6% – indication level I, 3.6% – level IIa, 11.8% – level IIb). HUT was positive in 292P (69.7%) – 77.1% after nitroglycerin administration (vasodepressor – 170P, cardioinhibitory – 53P, mixed – 62P and dysautonomic – 7P). Cardioinhibitory (CI) response predominated in the younger, and vasodepressor in the older P. Of the P with CI response, 41.5% had asystole (median of 41.4s, minimum 7.5s, maximum 115s). All P were instructed in the need to avoid triggering factors and perform counterpressure maneuvers. A pacemaker was implanted in 24P (5.7% of all population, due to long sinus pauses and asystole). Twenty-four P (5.7%) completed a tilt training program.

Conclusion

Most of the HUT were requested for syncope/presyncope, frequently according to the guidelines. There was a high rate of positive tests, with a predominance of vasodepressive response, particularly in the elderly.

Funding Acknowledgement

Type of funding source: None

Covalent Grafting of Polyoxometalate Hybrids onto Flat Silicon/Silicon Oxide: Insights from POMs Layers on Oxides

Immobilization of polyoxometalates (POMs) onto oxides is relevant to many applications in the fields of catalysis, energy conversion/storage, or molecular electronics. Optimization and understanding the molecule/oxide interface is crucial to rationally improve the performance of the final molecular materials. We herein describe the synthesis and covalent grafting of POM hybrids with remote carboxylic acid functions onto flat Si/SiO₂ substrates. Special attention has been paid to the characterization of the molecular layer and to the description of the POM anchoring mode at the oxide interface through the use of various characterization techniques, including ellipsometry, AFM, XPS, and FTIR. Finally, electron transport properties were probed in a vertical junction configuration and energy level diagrams have been drawn and discussed in relation with the POM molecular electronic features inferred from cyclic-voltammetry, UV-visible absorption spectra, and theoretical calculations. The electronic properties of these POM-based molecular junctions are driven by the POM LUMO (d-orbitals) whatever the nature of the tether or the anchoring group.

Melhora no Consumo Máximo de Oxigênio e na Ventilação após Tratamento com Sacubitril-Valsartana

Fundamento

O tratamento com sacubitril-valsartana teve seu benefício prognóstico confirmado no ensaio PARADIGM-HF. No entanto, dados sobre alterações no teste de esforço cardiopulmonar (TECP) com o uso de sacubitril-valsartana são escassos.

Objetivo

O objetivo deste estudo foi comparar os parâmetros do TECP antes e depois do tratamento com sacubitril-valsartana.

Métodos

Avaliação prospectiva de pacientes com insuficiência cardíaca (IC) crônica e fração de ejeção do ventrículo esquerdo ≤40%, mesmo sob terapia padrão otimizada, que iniciaram tratamento com sacubitril-valsartana, sem expectativa de tratamentos adicionais para a IC. Os dados do TECP foram coletados na semana anterior e 6 meses depois do tratamento com sacubitril-valsartana. Diferenças estatísticas com valor p <0,05 foram consideradas significativas.

Resultados

De 42 pacientes, 35 (83,3%) completaram o seguimento de 6 meses, uma vez que 2 (4,8%) morreram e 5 (11,9%) interromperam o tratamento devido a eventos adversos. A média de idade foi de 58,6±11,1 anos. A classe NYHA (classificação da New York Heart Association) melhorou em 26 (74,3%) pacientes. O consumo máximo de oxigênio (VO₂max) (14,4 vs. 18,3 ml/kg/min, p<0,001), a inclinação VE/VCO₂ (36,7 vs. 31,1, p<0,001) e a duração do exercício (487,8 vs. 640,3 s, p<0,001) também melhoraram com o uso de sacubitril-valsartana. O benefício foi mantido mesmo com a dose de 24/26 mg (13,5 vs. 19,2 ml/kg/min, p=0,018) de sacubitril-valsartana, desde que esta tenha sido a maior dose tolerada.

Conclusões

O tratamento com sacubitril-valsartana está associado a uma melhora acentuada do VO₂max, da inclinação VE/VCO₂ e da duração do exercício no TECP. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

NPC1 silent variant induces skipping of exon 11 (p.V562V) and unfolded protein response was found in a specific Niemann-Pick type C patient

Background

Niemann‐Pick type C (NPC, MIM #257220) is a neuro‐visceral disease, caused predominantly by pathogenic variants in the NPC1 gene. Here we studied patients with clinical diagnosis of NPC but inconclusive results regarding the molecular analysis.

Methods

We used a Next‐Generation Sequencing (NGS)‐panel followed by cDNA analysis. Latter, we used massively parallel single‐cell RNA‐seq (MARS‐Seq) to address gene profiling changes and finally the effect of different variants on the protein and cellular levels.

Results

We identified novel variants and cDNA analysis allowed us to establish the functional effect of a silent variant, previously reported as a polymorphism. We demonstrated that this variant induces the skipping of exon 11 leading to a premature stop codon and identified it in NPC patients from two unrelated families. MARS‐Seq analysis showed that a number of upregulated genes were related to the unfolded protein response (UPR) and endoplasmic reticulum (ER) stress in one specific patient. Also, for all analyzed variants, the NPC1 protein was partially retained in the ER.

Conclusion

We showed that the NPC1 silent polymorphism (p.V562V) is a disease‐causing variant in NPC and that the UPR is upregulated in an NPC patient.

Assessing Lysosomal Disorders in the NGS Era: Identification of Novel Rare Variants

Lysosomal storage diseases (LSDs) are a heterogeneous group of genetic disorders with variable degrees of severity and a broad phenotypic spectrum, which may overlap with a number of other conditions. While individually rare, as a group LSDs affect a significant number of patients, placing an important burden on affected individuals and their families but also on national health care systems worldwide. Here, we present our results on the use of an in-house customized next-generation sequencing (NGS) panel of genes related to lysosome function as a first-line molecular test for the diagnosis of LSDs. Ultimately, our goal is to provide a fast and effective tool to screen for virtually all LSDs in a single run, thus contributing to decrease the diagnostic odyssey, accelerating the time to diagnosis. Our study enrolled a group of 23 patients with variable degrees of clinical and/or biochemical suspicion of LSD. Briefly, NGS analysis data workflow, followed by segregation analysis allowed the characterization of approximately 41% of the analyzed patients and the identification of 10 different pathogenic variants, underlying nine LSDs. Importantly, four of those variants were novel, and, when applicable, their effect over protein structure was evaluated through in silico analysis. One of the novel pathogenic variants was identified in the GM2A gene, which is associated with an ultra-rare (or misdiagnosed) LSD, the AB variant of GM2 Gangliosidosis. Overall, this case series highlights not only the major advantages of NGS-based diagnostic approaches but also, to some extent, its limitations ultimately promoting a reflection on the role of targeted panels as a primary tool for the prompt characterization of LSD patients.

Lysosomal Storage Disease-Associated Neuropathy: Targeting Stable Nucleic Acid Lipid Particle (SNALP)-Formulated siRNAs to the Brain as a Therapeutic Approach

More than two thirds of Lysosomal Storage Diseases (LSDs) present central nervous system involvement. Nevertheless, only one of the currently approved therapies has an impact on neuropathology. Therefore, alternative approaches are under development, either addressing the underlying enzymatic defect or its downstream consequences. Also under study is the possibility to block substrate accumulation upstream, by promoting a decrease of its synthesis. This concept is known as substrate reduction therapy and may be triggered by several molecules, such as small interfering RNAs (siRNAs). siRNAs promote RNA interference, a naturally occurring sequence-specific post-transcriptional gene-silencing mechanism, and may target virtually any gene of interest, inhibiting its expression. Still, naked siRNAs have limited cellular uptake, low biological stability, and unfavorable pharmacokinetics. Thus, their translation into clinics requires proper delivery methods. One promising platform is a special class of liposomes called stable nucleic acid lipid particles (SNALPs), which are characterized by high cargo encapsulation efficiency and may be engineered to promote targeted delivery to specific receptors. Here, we review the concept of SNALPs, presenting a series of examples on their efficacy as siRNA nanodelivery systems. By doing so, we hope to unveil the therapeutic potential of these nanosystems for targeted brain delivery of siRNAs in LSDs.

Development of an Antisense Oligonucleotide-Mediated Exon Skipping Therapeutic Strategy for Mucolipidosis II: Validation at RNA Level

Lysosomal storage disorders (LSDs) are a group of rare inherited metabolic diseases caused by the malfunction of the lysosomal system, which results in the accumulation of undergraded substrates inside the lysosomes and leads to severe and progressive pathology. Despite there currently being a broad understanding of the molecular defects behind LSDs, curative therapies have been approved for only few of these diseases, whereas existing treatments are still mostly symptomatic with several limitations. Mucolipidosis type II alpha/beta (ML II) is one of most severe LSDs, which is caused by the total deficiency of the GlcNAc-1-phosphotransferase, a key enzyme for the formation of specific targeting signals on lysosomal hydrolases to lysosomes. GlcNAc-1-phosphotransferase is a multimeric enzyme complex encoded by two genes: GNPTAB and GNPTG. One of the most frequent ML II causal mutation is a dinucleotide deletion on exon 19 of GNPTAB (c.3503_3504del) that leads to the generation of a truncated protein, loss of GlcNAc-1-phosphotransferase activity, and missorting of multiple lysosomal enzymes. Presently, there is no therapy available for ML II. In this study, we explored the possibility of an innovative therapeutic strategy for ML II based on the use of antisense oligonucleotides (AOs) capable to induce the skipping of GNPTAB exon 19 harboring the most common disease-causing mutation, c.3503_3504del. The approach confirmed the ability of specific AOs for RNA splicing modulation, thus paving the way for future studies on the therapeutic potential of this strategy.

Risk and limits in dental practice: a Portuguese approach to medical-legal evaluation and professional liability

Patient safety and quality of healthcare delivery systems are an objective of WHO. This study aims to present and analyse Portuguese clinical data on risk and malpractice in dental practice. Data from the Forensic Dentistry Laboratory (Faculty of Medicine, University of Coimbra) was analysed, between the years of 2013 to 2018. One hundred and seven technical reports were selected, and seventy nine files were included in the iatrogenic sequelae group. Data included the analysis of the performance of dental professionals. Sequelae were divided in descending order of occurrence:1) mandibular dysfunction (53,2%)[(42)79]; 2) neurological deficit (39,2%)[(31)79]; 3) tooth loss (6,3%)[(5)79]; and 4) opening deficit (1,3%)[(1)79].Three major areas with significant expression in the field of expert evaluations were analysed: 1) orthodontic treatment (51,9%), implant rehabilitation (29,1%), and oral surgery. Given the prevalence of malpractice, the need to assess its causes and recognise standards for its prevention is necessary.

Can psychosocial work factors influence psychologists' positive mental health?

BACKGROUND

Working in healthcare can entail intense emotional demands that increases susceptibility to occupational risk factors. Psychosocial risk assessment can contribute to promoting awareness of the effects of work on positive mental health.

AIMS

To explore and analyse the influence of psychosocial work factors on positive mental health among psychologists.

METHODS

A cross-sectional study of 339 psychologists was conducted. Two instruments were used for data collection: the Mental Health Continuum-Short Form (MHC-SF) to assess well-being and the Health and Work Survey (INSAT) to assess psychosocial work factors.

RESULTS

This study identified psychosocial work factors that affect psychologists' positive mental health, namely, emotional well-being was affected by 'Need help from colleagues' (β = -1.091), 'Have no one I can trust' (β = -1.253) and 'Complex work' (β = 0.751); psychological well-being was affected by 'Intense work pace' (β = 1.151), 'Not able to participate in decisions' (β = -3.695) and 'Complex work' (β = 1.520); and social well-being was affected by 'Always changing roles and tasks' (β = -1.810) and 'Not able to participate in decisions' (β = -2.470).

CONCLUSIONS

Psychosocial work factors such as work organization, work relationships and emotional demands influence psychologists' positive mental health. Social support at the workplace and having challenging and autonomous work can promote mental health. It is important to develop better organizational practices to promote mental health and well-being among these professionals.

Psychiatric symptoms in Huntington's disease the importance of reliable information – A case report

Introduction

Huntington's Disease is an autosomal dominant neurodegenerative disease characterized by motor, psychiatric and cognitive symptoms. Irritability, affective disorders, apathy and psychosis are among the most frequent psychiatric symptoms and can predate the pre-clinical period.

Objective

The authors’ goal is to understand the complexity of Huntington's disease clinical presentation. Additionally, we present an illustrative clinical case.

Aims

To convey the importance of collecting reliable information in order to make a proper diagnosis.

Methods

A PubMed database review was performed using “Psychiatry”, “Psychiatric”, “Symptoms” and “Huntington's Disease” as keywords; retrieved papers were selected according to their relevance. The patient clinical record was reviewed.

Results

The authors report a case of a 39-year-old woman, who was referred in 2014, to a psychiatrist because of depressive mood and suicidal ideation with two suicidal attempts in the past 5 years. However, she did not disclose her family history of Huntington's disease neither to her GP nor her psychiatrist. She never complied with the treatment plan and was admitted, in November, into a psychiatric unit because of subtle motor changes and apathy, which had resulted in personal neglect. The diagnosis could only be made after a family interview was held and the family medical history was revealed.

Conclusions

Corroborative history from caregivers is of extreme importance in psychiatry. Early detection of symptoms can help mitigate the disease social impact. In our patient's case, by the time of proper diagnosis, she was estranged from her family and had endured distressing psychiatric symptoms without adequate treatment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The effects on the acoustic parameters and auditory-perceptive characteristics of voice in children submitted to adenoidectomy with or without tonsillectomy

OBJECTIVES

To analyse the possible changes on the acoustic parameters and auditory-perceptive characteristics of children's voice after adenoidectomy with or without tonsillectomy.

METHODS

Prospective cohort study of children aged 5-12 years at one month before surgery (t0) and one (t1), three (t3) and six (t6) months after adenoidectomy with or without tonsillectomy. On each assessment the acoustic parameters (fundamental frequency, jitter %, shimmer % and harmonics-to-noise ratio) and auditory-perceptive analysis (nasal resonance, loudness, pitch, GRBAS scale and maximum phonation time) were recorded.

RESULTS

A total of 51 children were considered for data analysis. Nasal resonance revealed a significant decrease in the number of cases with hyponasality, from 86.3% at t0 to 12.8% at t1 (p < 0.001), 2.3% at t3 (p < 0.001) and 2.8% at t6 (p < 0.001). This improvement was maintained during the late follow-up time with no significant difference on nasal resonance between t0 and t3 (p = 0.250) and t3 and t6 (p = 0.250). All children with alteration on the GRBAS scale before the procedure showed a normal voice quality after the surgery. Regarding the acoustic parameters none showed a significant change with the surgery.

CONCLUSIONS

The results suggest that adenoidectomy with or without tonsillectomy is a safe procedure concerning voice alterations and can improve voice quality and nasal resonance in a sustained manner.

P2516Cardiac rehabilitation program - experience and outcomes in a tertiary center

Introduction

Cardiac rehabilitation (CR) programs are effective in improving functional capacity and reducing mortality. The level of adherence to them seems to be less than the ideal, and some factors can predict non-compliance with impact on outcomes.

Purpose

The aim was to characterize the population of the cardiac rehabilitation (CR) appointment, determine factors predictive of compliance with the standard CR exercise program and evaluate the benefits of the program.

Methods

Retrospective analysis of patients in a CR appointment at a single center between 2014 and 2017. Patients (P) were divided into two groups: compliance >80% of the program (GI) and non-compliance (GII). We assessed clinical, laboratory, and echocardiographic characteristics and determined predictors for compliance and compared the follow-up to date.

Results

270P (83% men) were included, with a mean age of 57 years. The P had a median follow up of 35 months, with an interquartil interval of 28 months. The majority (92.5%) had at least one cardiovascular risk factor (25.1% diabetes, 57.1% hypertension, 72.8% dyslipidemia, 75.8% obesity or weight excess, with mean body mass index (BMI) 27.3±3.46, 16.7% family history, 19.8% acute myocardial infarction (AMI), 48.2% smoking). 99% of the patients were medicated (93.7% acetylsalicylic acid, 67.3% clopidogrel, 24.1% ticagrelor, 95.6% beta-blocker, 93.7% ACEI/ARB, 95.5% statin). 144P (53.3%) were not from Lisbon. Most patients (77%) were referred after AMI, 8.9% with heart failure (HF), 8.5% with stable or unstable coronary disease and 1.9% with valvulopathy. 69P (25.6%) attended >80% of the CR program. Death occurred in 4.4% of the P (71.4% cardiovascular causes) and 27% had at least 1 hospitalization. Age, sex, economic insufficiency and residence local (Lisbon or non-Lisbo) were not predictors of non-compliance (p=0.859, p=0.656, p=0.914 and p=0.515 respectively). Predictors of non-compliance were higher IMC (CC=-0.141, p=0.014), higher cholesterol (CC=-0.140, p=0.016), higher C reactive protein (CC=-0.120, p=0.043), higher HbA1c (CC=-0.170, p=0.008) and CR for heart failure (HF) (OR = 0.715, IC [0.659–0.775], p=0.002). Of these, higher HbA1C (p=0.018) and CR for HF (p=0.034) were independent predictors. Compliance with>80% of the program was associated with lower overall mortality (OR = 0.732, IC [0.679–0.788], p=0.037), but not as an independent factor (p=0.378). The only independent predictor of mortality were BNP (p<0.0001).

Conclusion

Of the patients referred to the CR consultation one fourth concludes the program. Several factors can predict non-compliance, with higher HbA1c and CR for HF being independent predictors. Compliance with the CR program is associated with lower overall mortality.

P2510Cardiorespiratory optimal point as a predictor of outcomes in patients enrolled in a cardiac rehabilitation program

Introduction

The cardiopulmonary exercise test (CEPT) allows the evaluation of peak and sub-maximal tolerance to the effort, giving us relevant information for clinical decisions. Evidence has emerged that Cardiorespiratory Optimal Point (COP)>30, calculated as the minimum ratio between ventilation and oxygen (VE/VO2) may be a good predictor of events.

Purpose

The aim was to characterize the population of the cardiac rehabilitation (CR) appointment that performed CEPT, evaluate COP as a predictor of events and determine the best cut off for our population.

Methods

Retrospective analysis of CR appointment patients who performed CEPT between 2014 and 2017 in a single center. We compared the mortality and hospitalizations according to COP and COP>30. We established the appropriate Cut Off for our population and compared the same with the occurrence of events.

Results

207Patients (P) (83.6% men) were included, with a mean age of 57 years. The mean COP was 23.6±5.8 (IC [24.06–25.66]). 15.9% P had COP >30 and 33.8% had COP<22. The majority (96.6%) had a cardiovascular disease or risk factors and 99% were medicated. The majority (87.9%) was referred for CR with isquemic cardiopathy (AMI or stable or unstable coronary disease), 9.2% with heart failure (HF) and 9.2% with valvulopathy. 6.9% P died from any cause, 33.8% had an hospitalization (78.6% from a cardiovascular reason). Higher COP values correlated with higher number of all causes hospitalizations (H) (CC = 0.123, p=0.032), cardiovascular H (CC = 0.123, p=0.032), heart failure H (CC = 0.189, p=0.001) and device placement H (CC = 0.173, p=0.003). COP did not correlate with mortality (p=0.453). The cut off of 30 only correlated with HF hospitalization in this population (OR = 5, IC [1.429–17.494] p=0.006). In our population, COP was a good predictor for all cause H and heart failure H (AUC = 0.8 in both). A cut off of 25 had a sensitivity (S) of 78% with a specificity (E) of 70% for all cause hospitalization and S 73% and E 68% for heart failure H. Values above this cut off correlate with more all cause H (OR = 1,928, IC [1.06–3.507], p=0.031) and heart failure H (OR = 5.63, IC [1,44–21.94]), p=0.006). COP was an independent predictor of all-cause H (p=0.018) and heart failure H (p<0.0001). Other independent predictors of HF hospitalization are BNP (p=0.0011) and ejection fraction (p<0.0001).

Conclusion

COP was a good independent predictor of all-cause hospitalizations and HF hospitalization. In our population the cut off 25 for COP had the greatest S and E for predicting events. In our population this factor was not a good predictor of mortality.

RNA Therapeutics: How Far Have We Gone?

In recent years, the RNA molecule became one of the most promising targets for therapeutic intervention. Currently, a large number of RNA-based therapeutics are being investigated both at the basic research level and in late-stage clinical trials. Some of them are even already approved for treatment. RNA-based approaches can act at pre-mRNA level (by splicing modulation/correction using antisense oligonucleotides or U1snRNA vectors), at mRNA level (inhibiting gene expression by siRNAs and antisense oligonucleotides) or at DNA level (by editing mutated sequences through the use of CRISPR/Cas). Other RNA approaches include the delivery of in vitro transcribed (IVT) mRNA or the use of oligonucleotides aptamers. Here we review these approaches and their translation into clinics trying to give a brief overview also on the difficulties to its application as well as the research that is being done to overcome them.