A Case of Isolated Left Ventricular Noncompaction with Basal ECG-Tracing Strongly Suggestive for Type-2 Brugada Syndrome

Isolated left ventricular noncompaction (ILVNC) is a cardiomyopathy caused by intrauterine arrest of compaction of the myocardial fibres and meshwork, an important process in myocardial development. ILVNC is clinically accompanied by depressed ventricular function, arrhythmias, and systemic embolization. We reported a case of ILVNC with basal ECG-tracing strongly suggestive for type-2 Brugada syndrome (BrS). Up to now, this is the first report investigating the association between ILVNC and this particular ECG pattern

Infrared nanospectroscopy depth-dependent study of modern materials: morpho-chemical analysis of polyurethane/fibroin binary meshes

Infrared scattering-type scanning near-field optical microscopy (IR s-SNOM) and imaging is here exploited together with attenuated total reflection (ATR) IR imaging and scanning electron microscopy (SEM) to depict the chemical composition of fibers in hybrid electrospun meshes. The focus is on a recently developed bio-hybrid material for vascular tissue engineering applications, named Silkothane & REG;, obtained in the form of nanofibrous matrices from the processing of a silk fibroin-polyurethane (SFPU) blend via electrospinning. Morphology and chemistry of single fibers, at both surface and subsurface level, have been successfully characterized with nanoscale resolution, taking advantage of the IR s-SNOM capability to portray the nanoscale depth profile of this modern material working at diverse harmonics of the signal. The applied methodology allowed to describe the superficial characteristics of the mesh up to a depth of about 100 nm, showing that SF and PU do not tend to co-aggregate to form hybrid fibers, at least at the length scale of hundreds of nanometers, and that subdomains other than the fibrillar ones can be present. More generally, in the present contribution, the depth profiling capabilities of IR s-SNOM, so far theoretically predicted and experimentally proven only on model systems, have been corroborated on a real material in its natural conditions with respect to production, opening the room for the exploitation of IR s-SNOM as valuable technique to support the production and the engineering of nanostructured materials by the precise understanding of their chemistry at the interface with the environment

Variabilities in global DNA methylation and β\beta-sheet richness establish spectroscopic landscapes among subtypes of pancreatic cancer

Purpose: Knowledge about pancreatic cancer (PC) biology has been growing rapidly in recent decades. Nevertheless, the survival of PC patients has not greatly improved. The development of a novel methodology suitable for deep investigation of the nature of PC tumors is of great importance. Molecular imaging techniques, such as Fourier transform infrared (FTIR) spectroscopy and Raman hyperspectral mapping (RHM) combined with advanced multivariate data analysis, were useful in studying the biochemical composition of PC tissue. Methods: Here, we evaluated the potential of molecular imaging in differentiating three groups of PC tumors, which originate from different precursor lesions. Specifically, we comprehensively investigated adenocarcinomas (ACs): conventional ductal AC, intraductal papillary mucinous carcinoma, and ampulla of Vater AC. FTIR microspectroscopy and RHM maps of 24 PC tissue slides were obtained, and comprehensive advanced statistical analyses, such as hierarchical clustering and nonnegative matrix factorization, were performed on a total of 211,355 Raman spectra. Additionally, we employed deep learning technology for the same task of PC subtyping to enable automation. The so-called convolutional neural network (CNN) was trained to recognize spectra specific to each PC group and then employed to generate CNN-prediction-based tissue maps. To identify the DNA methylation spectral markers, we used differently methylated, isolated DNA and compared the observed spectral differences with the results obtained from cellular nuclei regions of PC tissues. Results: The results showed significant differences among cancer tissues of the studied PC groups. The main findings are the varying content of β-sheet-rich proteins within the PC cells and alterations in the relative DNA methylation level. Our CNN model efficiently differentiated PC groups with 94% accuracy. The usage of CNN in the classification task did not require Raman spectral data preprocessing and eliminated the need for extensive knowledge of statistical methodologies. Conclusions: Molecular spectroscopy combined with CNN technology is a powerful tool for PC detection and subtyping. The molecular fingerprint of DNA methylation and β-sheet cytoplasmic proteins established by our results is different for the main PC groups and allowed the subtyping of pancreatic tumors, which can improve patient management and increase their survival. Our observations are of key importance in understanding the variability of PC and allow translation of the methodology into clinical practice by utilizing liquid biopsy testing

On the lookout for influenza viruses in Italy during the 2021-2022 season: along came A(H3N2) viruses with a new phylogenetic makeup of their hemagglutinin

Aims: To assess influenza viruses (IVs) circulation and to evaluate A(H3N2) molecular evolution during the 2021-2022 season in Italy. Materials and methods: 12,393 respiratory specimens (nasopharyngeal swabs or broncho-alveolar lavages) collected from in/outpatients with influenza illness in the period spanning from January 1, 2022 (week 2022-01) to May 31, 2022 (week 2022-22) were analysed to identify IV genome and molecularly characterized by 12 laboratories throughout Italy. A(H3N2) evolution was studied by conducting an in-depth phylogenetic analysis of the hemagglutinin (HA) gene sequences. The predicted vaccine efficacy (pVE) of vaccine strain against circulating A(H3N2) viruses was estimated using the sequence-based Pepitope model. Results: The overall IV-positive rate was 7.2% (894/12,393), all were IV type A. Almost all IV-A (846/894; 94.6%) were H3N2 that circulated in Italy with a clear epidemic trend, with 10% positivity rate threshold crossed for six consecutive weeks from week 2022-11 to week 2022-16. According to the phylogenetic analysis of a subset of A(H3N2) strains (n=161), the study HA sequences were distributed into five different genetic clusters, all of them belonging to the clade 3C.2a, sub-clade 3C.2a1 and the genetic subgroup 3C.2a1b.2a.2. The selective pressure analysis of A(H3N2) sequences showed evidence of diversifying selection particularly in the amino acid position 156. The comparison between the predicted amino acid sequence of the 2021-2022 vaccine strain (A/Cambodia/e0826360/2020) and the study strains revealed 65 mutations in 59 HA amino acid positions, including the substitution H156S and Y159N in antigenic site B, within major antigenic sites adjacent to the receptor-binding site, suggesting the presence of drifted strains. According to the sequence-based Pepitope model, antigenic site B was the dominant antigenic site and the p(VE) against circulating A(H3N2) viruses was estimated to be -28.9%. Discussion and conclusion: After a long period of very low IV activity since public health control measures have been introduced to face COVID-19 pandemic, along came A(H3N2) with a new phylogenetic makeup. Although the delayed 2021-2022 influenza season in Italy was characterized by a significant reduction of the width of the epidemic curve and in the intensity of the influenza activity compared to historical data, a marked genetic diversity of circulating A(H3N2) strains was observed. The identification of the H156S and Y159N substitutions within the main antigenic sites of the most of sequences also suggested the circulation of drifted variants with respect to the 2021-2022 vaccine strain. Molecular surveillance plays a critical role in the influenza surveillance architecture and it has to be strengthened also at local level to timely assess vaccine effectiveness and detect novel strains with potential impact on public health

High pressure studies of amyloid proteins

2010/2011In questa tesi viene presentato lo studio di due proteine amiloidi, l'insulina e l' -sinucleina , condotto attraverso l'utilizzo della spettroscopia infrarossa a trasformata di Fourier in alta pressione. Con il nome di brille amiloidi ci si riferisce ad aggregati proteici altamente ordinati che si vengono a depositare in diversi organi o tessuti durante lo sviluppo di molte importanti patologie, le amiloidosi. Tra queste, vista la crescente di usione nelle popolazioni occidentali, vale la pena citare il morbo di Parkinson, e il morbo di Alzheimer. Le conoscenze relative alla termodinamica degli aggregati amiloidi e alle cinetiche di aggregazione sono ancora limitate. Ci o che maggiormente complica la ricerca di strategie atte ad inibire la reazione e la sostanziale irreversibilit a del processo di aggregazione. Le brille amiloidi dimostrano infatti una sorprendente stabilit a termodinamica. L'introduzione di tecniche di alta pressione nello studio dei sistemi biologici ha negli ultimi anni evidenziato le potenzialit a e l'utilit a della bio sica delle alte pressioni in particolare nello studio degli stati conformazionali delle proteine . Attraverso una variazione di pressione, si possono infatti gestire le distanze intra- e inter-molecolari in modo controllato. Dal presente studio emerge che l'applicazione dell'alta pressione e in grado di indurre la rottura degli aggregati amiloidi con un'e cienza che dipende dallo stato di maturazione della brilla (nel caso dell'insulina) e dalla speci ca mutazione genetica (nel caso della sinucleina). E' stato inoltre individuata una sequenzialit a nel processo di dissociazione indotto, che sembra ri ettere la pre-esistente gerarchia di strutture della catena peptidica. Attraverso l'applicazione dell'alta pressione e stato dunque possibile stabilizzare stati intermedi di brillazione. Quest'ultimo rappresenta il punto di forza della bio sica in alta pressione, che permette di popolare e quindi caratterizzare stati energeticamente instabili a pressione ambiente, fornendo dunque nuove linee di ricerca da seguire per la comprensione delle amiloidosi.In this thesis is presented the investigation of the infrared properties at high pressures of two amyloidogenic proteins: insulin and -synuclein. Amyloid brils are highly ordered protein aggregates occurring during the development of many serious diseases, like Alzheimer's and Parkinson's diseases. Despite a major e ort both from the biological and biophysical communities, very little is known about the thermodynamics of the aggregated protein state and the kinetic mechanisms of its formation. Fibrillation is an irreversible process and a key challenge is the development of therapeutical strategies able to inhibit or reverse the formation of amyloids. Hydrostatic pressure has proven to be a powerful tool for the study of biological systems. Contrary to temperature - whose e ects show both on volume and thermal energy simultaneously - pressure leads to a controlled change of inter- and intramolecular distances, and enables to determine the stability of a protein structure. From the present study, it comes out that high pressure is able to induce the disaggregation of brils with an e cacy which depends on the maturation stage (insulin) and on speci c point mutations (synuclein). Our results show how high pressure disaggregation occurs following a sequential mechanism that re ects the protein's structure hierarchy. Pressure allows to address intermediate states, which are probably occurring along the aggregation reaction pathway, thus providing a new clue to the understanding of amyloidosis.XXIV Ciclo197

FTIR analysis of the high pressure response of native insulin assemblies

It is widely recognized that a central role in conferring stability to the structure of proteins against misfolding and aggregation is played by the formation of oligomers. The case of insulin is prototypical in this respect: in our body it is stored up in stable inactive hexameric assemblies whereas only in its monomeric form it recovers the role of regulating carbohydrate and fat metabolism. In the present paper, exploiting the optimal coupling between FTIR spectroscopy and diamond anvil cell technique, we probe the stability of different insulin oligomeric forms under high pressure, namely over the ranges 0–15 kbar for water solution and 0–80 kbar for dry powder. Results obtained show different responses to volume compression for the different assemblies being the structure of monomers and dimers remarkably more affected by compression than hexamers. Moreover by comparing the results obtained using water solution and dry powder we were able to draw important considerations about the role of water in the high pressure unfolding processes

Infrared HP study of protein folding and aggregation @ the SISSI Elettra beamline

Fourier transform infrared spectroscopy (FTIR) coupled with High Hydrostatic Pressure technology is a suitable technique to investigate unfolding/misfolding processes providing useful information on the kinetics of aggregation of proteins. Since HHP doesn't affect the enthalpic contribution to the Gibbs free energy, it is able to perturb the secondary structure of proteins in a reversible way . The principle governing pressure effects is that it tends to shift a system towards the state that occupies the smallest volume, it causes the electrostriction of charged and polar groups, the elimination of packing defects, and the solvation of hydrophobic groups. Cavities and packing defects are expected to be major contributors to volume changes and their presence will make the system more susceptible to pressure unfolding/dissociation. Because high pressure allows stabilization of folding intermediates such as molten-globule conformations, this method provides an unique opportunity for their characterization. We present here latest developments in the set up of a high pressure infrared facility for the study of protein folding misfolding and aggregations at the SISSI beamline at Elettra

Infrared Microspectroscopy study of insulin crystals at high pressure

During the last years the coupling of high pressure techniques and infrared spectroscopy has proven to be a very powerful tool in the study of conformational changes of proteins. Protein unfolding and monomerization are events that are expected to take place at high pressure due to the peculiarity of pressure to shift the system towards the state that occupies the minimum volume. We observed the growth of apparently cubic crystals at a pressure of about 4 kbar, subjecting to high pressure a solution of misfolded insulin. Even if high pressure is commonly used to tune the growth rate of crystals, protein crystallization at high pressure is not a well known process and no evidences of the particular case of insulin are present in literature

Raman analysis of insulin denaturation induced by high-pressure and thermal treatments

Raman spectroscopy has been used to investigate different conformational states of bovine pancreatic insulin: the native form and several structurally modified states with different extent of denaturation induced by thermo-chemical treatment and by applying very high pressure (up to 8 GPa) using a diamond anvil cell. High-pressure results confirm the peculiar strength to volume compression of insulin and largely extend the pressure range of its structural stability (0-4.2 GPa). Above 4.2 GPa, insulin undergoes an irreversible structural transition that, once pressure is released, leaves the sample in a new conformational state. The protein secondary structure after the pressure treatment results in a structure that is somewhat intermediate between that of the native and the thermo-chemical fibrillar samples. The analysis of the pressure dependence of the Raman spectrum and of several specific spectroscopic markers allows us to follow the path from the native to new pressure-denatured protein conformation