1,721,115 research outputs found
Studio del ruolo di mutazioni missenso di CDC73 e microRNA in tumori CDC73-correlati familiari e sporadici
Full text linkMutations of the CDC73 oncosuppressor gene, encoding for parafibromin, are associated with the HPT-JT syndrome, an autosomic dominant syndrome whose clinical manifestations are mainly parathyroid tumors and, less frequently, ossifying fibromas of the jaws and various types of benign or malignant uterine and renal anomalies.
There are no data in the literature about CDC73 mutational status in ossifying jaw tumors from HPT-JT patients.
In the present study, we identified a novel CDC73 missense substitution, Ile60Asn, in the mandibular tumor of a patient from a well-characterized HPT-JT kindred with a germline frameshift mutation in the CDC73 gene. Missense mutations of the CDC73 oncosuppressor gene are very rare and often involve residues at the N-terminal of parafibromin, whose structure and function are to date unknown.
According to an in silico prediction, the Ile60Asn substitution was predicted to be pathogenetic and involved a conserved amino acid. In order to analyze in vitro the tumorigenic potential of this mutation, we performed transfection experiments in HEK293A cells to assess effects on subcellular localization, mutant protein amount, cell proliferation, apoptosis, and cyclin D1 and c-Myc expression. We demonstrated that the Ile60Asn mutant was less expressed than the wild-type protein, lacked nucleolar localization, was less able to decrease cyclin D1 expression, and increased the percentage of cells in the G2-M phases of cellular cycle. No effects were observed on c-Myc expression and on induction of spontaneous apoptosis.
In conclusion, the Ile60Asn mutation exibited dominant interfering properties and not only determined production of an inactive parafibromin. The nucleolar localization of parafibromin is likely crucial to fully elicit the antiproliferative effects of parafibromin.
These results indicate that ossifying fibromas of the jaw arising in patients with HPT-JT syndrome are not secondary effects of hyperparathyroidism, but occur for a second distinct mutational event in the CDC73 gene.
CDC73 mutations are involved not only in familial forms of primary hyperparathyroidism; inactivating CDC73 mutations are found in 77% of sporadic malignant parathyroid tumors. A high percentage of sporadic carcinomas with CDC73 genetic anomalies shows a strong loss of immunoreactivity for parafibromin. By converse, in sporadic parathroid adenomas, CDC73 seems not to have a clear pathogenetic role: alterations in this gene are very rare (0-4%) in benign tumors.
Nevertheless, in previous observations of our research group, parafibromin immunoreactivity showed great variability, with no significant difference between benign and malignant sporadic parathyroid tumors. In addition, some cases of sporadic parathyroid adenomas without CDC73 mutations with low parafibromin expression were observed. We can hypothesize the presence of mechanisms different from CDC73 mutations that might result in decrease of parafibromin expression, like down-regulation by microRNAs (miRNAs). To date, in the literature there are only two studies on miRNAs expression profile in sporadic parathyroid tumors. We performed miRNA-profiling with miRNA-microarrays on 8 sporadic parathyroid adenomas and 3 sporadic parathyroid carcinomas, in order to identify differentially expressed miRNAs. A SAM approach failed to demonstrate significantly different miRNAs in sporadic adenomas vs. carcinomas, while Gene Set Enrichment Analysis on cell pathways-associated miRNAs found an enrichment for miRNAs linked to PKC and PTEN pathway in adenomas and for miRNAs linked to SHH pathway in carcinomas.
We selected for further analysis miR-9, acting in both PKC and PTEN pathways, and predicted in silico to target CDC73. Luciferase assay and western blot in HEK293A cells showed that miR-9 is able to downregulate parafibromin expression. In addition, there was an indirect effect on cyclin D1 expression, that was upregulated in cells transfected with miR-9.
In paraffin-embedded sections of the tumor tissues employed for miRNA-microarray analysis, there were no correlations between miR-9 level in real-time RT PCR and parafibromin or cyclin D1 immunoreactivity.
In conclusion, in sporadic parathyroid tumors we failed to demonstrate miRNAs differentially expressed between benign and malignant neoplasms. MiR-9 targets CDC73 in vitro, but in vivo it seems not to account for differences in parafibromin and cyclin D1 immunoreactivityMutazioni del gene oncosoppressore CDC73, codificante per parafibromina, sono associate alla sindrome da iperparatiroidismo-tumori mandibolari (HPT-JT): tale sindrome, a trasmissione autosomica dominante, è caratterizzata principalmente dall’insorgenza di tumori paratiroidei e, meno frequentemente, di fibromi ossificanti mandibolari e di vari tipi di anomalie uterine e renali, sia benigne che maligne.
In letteratura non esistono dati riguardo allo stato mutazionale di CDC73 nei fibromi ossificanti mandibolari dei pazienti HPT-JT.
Nel presente studio, è stata identificata una nuova mutazione somatica missenso di CDC73, Ile60Asn, nel tumore mandibolare di una paziente di una famiglia HPT-JT portatrice di una mutazione germinale frameshift di CDC73. Le mutazioni missenso di CDC73 sono molto rare, e spesso interessano residui nella porzione N-terminale di parafibromina, la cui funzione non è ancora nota.
Secondo una predizione in silico, la sostituzione Ile60Asn è verosimilmente patogenetica, e altera un amminoacido altamente conservato. Per studiare in vitro il potenziale tumorigenico della mutazione, sono stati effettuati esperimenti nella linea cellulare HEK293A per analizzare possibili effetti su localizzazione subcellulare e livello di espressione della proteina mutata, proliferazione cellulare, apoptosi ed espressione di ciclina D1 e c-Myc. E’stato osservato che il mutante Ile60Asn era meno espresso della sua controparte wild-type, era privo di localizzazione nucleolare e mostrava ridotta capacità di inibizione dell’espressione di ciclina D1; inoltre, la frazione cellulare nelle fasi G2-M risultava aumentata nelle cellule trasfettate con parafibromina mutata. Non sono stati osservati effetti sull’espresione di c-Myc e sull’induzione di apoptosi.
In conclusione, la mutazione Ile60Asn sembrava agire secondo un meccanismo di dominanza negativa, e non dare origina solamente ad una forma inattiva di parafibromina. La localizzazione nucleolare di parafibromina è verosimilmente cruciale per perrmettere alla proteina di esercitare le sue funzioni antiproliferative. Questi risultati indicano che i fibromi ossificanti mandibolari che insorgono in pazienti con HPT-JT non rappresentano effetti secondari dell’iperparatiroidismo, ma si presentano in seguito ad un secondo evento mutazionale a carico di CDC73.
Le mutazioni di CDC73 non sono responsabili solamente dell’insorgenza di forme familiari di iperparatiroidismo primitivo: mutazioni inattivanti di questo gene, infatti, vengono identificate nel 77% circa dei tumori paratiroidei sporadici maligni. Un’elevata percentuale di carcinomi sporadici con anomalie a carico di CDC73 mostra una forte perdita di immunoreattività per parafibromina. Al contrario, negli adenomi paratiroidei sporadici, CDC73 non sembra avere un ruolo patogenetico di primo piano, dato che risulta mutato molto raramente (0-4%) nei tumori benigni.
Tuttavia, secondo nostre precedenti esperienze, l’immunoreattività per parafibromina mostra elevata variabilità, senza differenze significative tra tumori paratiroidei sporadici benigni e maligni. Inoltre, sono stati osservati alcuni casi di adenoma paratiroideo sporadico privi di mutazioni di CDC73, ma con basso livello di espressione di parafibromina. E’quindi possibile ipotizzare l’esistenza di meccanismi, differenti dalla mutazione di CDC73, che possano causare una diminuzione dell’espressione di parafibromina: tra questi, una down-regolazione ad opera di microRNA (miRNA). Attualmente, in letteratura sono presenti solamente due studi sul profilo di espressione di miRNA nei tumori paratiroidei sporadici. Nel presente studio, è stato attuato un approccio di profiling con miRNA-microarrays in 8 adenomi e 3 carcinomi paratiroidei sporadici, per identificare miRNA differenzialmente espressi tra le due condizioni. L’analisi SAM non ha evidenziato miRNA significativamente differenti tra tumori benigni e maligni, mentre la Gene Set Enrichment Analysis su miRNA associati a determinate pathways cellulari ha identificato un arricchimento nei miRNA collegati alle pathways di PKC e PTEN negli adenomi, ed alla pathway di SHH nei carcinomi.
E’stato scelto per ulteriori approfondimenti sperimentali miR-9, collegato ad entrambe le vie PKC e PTEN, che ha fra i suoi target predetti in silico CDC73. Il saggio dell’attività luciferasica e il western blot in cellule HEK293A hanno dimostrato che miR-9 era in grado di diminuire l’espressione di parafibromina. Inoltre, era presente un effetto indiretto sull’espressione di ciclina D1, più espressa in cellule trasfettate con miR-9.
In sezioni incluse in paraffina dei tessuti tumorali impiegati per l’analisi con mirNA-microarrays, non sono state osservate correlazioni tra il livello di miR-9 e l’immunoreattività per parafibromina e ciclina D1.
In conclusione, nei tumori paratiroidei sporadici non è stata evidenziata la presenza di miRNA differenzialmente espressi tra adenomi e carcinomi. MiR-9 ha CDC73 come target in vitro, ma in vivo non sembra essere responsabile delle differnze di immunoreattività per parafibromina e ciclina D
Lightweight alkali activated composites by direct foaming based on ceramic tile waste and fly ash
Full text linkThis study aims at investigating for the first time if ceramic waste coming from the rectifying process of porcelain stoneware tiles are suitable to prepare alkali activated lightweight composites. After successfully designing alkali activated materials based on ceramic waste, different foaming agents were added alone or in combination with sodium dodecyl sulfate acting as pore stabilizing agent. Addition of expanded perlite as lightweight constituent was also tested. Different properties, such as geometric density, water absorption, porosity and pore size distribution by mercury intrusion porosimetry and SEM observations, and thermal conductivity, were measured in view of their potential future applications. The results highlight that combining ceramic tile waste as raw materials, hydrogen peroxide as foaming agent, sodium dodecyl sulfate as pore stabilizing agent and expanded perlite allow the preparation of optimized lightweight composites with a density of 0.75 g/cm3, a water absorption greater than 70 % and a thermal conductivity of 0.26 W/mK
GMH-D: Combining Google MediaPipe and RGB-Depth Cameras for Hand Motor Skills Remote Assessment
Full text linkImpairment in the execution of simple motor tasks involving hands and fingers could hint at a general worsening of health conditions, particularly in the elderly and in people affected by neurological diseases. The deterioration of hand motor function strongly impacts autonomy in daily activities and, consequently, the perceived quality of life. The early detection of alterations in hand motor skills would allow, for example, to promptly activate treatments and mitigate this discomfort. This preliminary study examines an innovative pipeline based on a single RGB-Depth camera and Google MediaPipe Hands, that is suitable for the remote assessment of hand motor skills through simple tasks commonly used in clinical practice. The study includes several phases. First, the quality of hand tracking is evaluated by comparing reconstructed and real hand 3D trajectories. The proposed solution is then tested on a cohort of healthy volunteers to estimate specific kinematic features for each task. Finally, these features are used to train supervised classifiers and distinguish between “normal” and “altered” performance by simulating typical motor behaviour of real impaired subjects. The preliminary results show the ability of the proposed solution to automatically highlight alterations in hand performance, providing an easy-to-use and non-invasive tool suitable for remote monitoring of hand motor skills
Automatic Detector of Gait Alterations using RGB-D sensor and supervised classifiers: a preliminary study
Full text linkAlterations in walking patterns are widespread in the elderly population due to the motor decline typical of aging and other comorbidities related to movement disorders, such as Parkinson’s disease, or the consequences of acute events such as stroke. Early detection allows promptly activating specific rehabilitation treatments to reduce the risk of falls, injuries, and hospitalizations. This paper presents a non-invasive solution based on Azure Kinect and machine learning to detect gait alterations (i.e., slow-speed gait, short-step gait, and dangling gait). The body tracking algorithm captures the 3D skeletal model during gait on a straight walking path compatible with domestic environments. Some parameters are estimated from the virtual skeleton to characterize gait objectively. These parameters are then fed to supervised classifiers to distinguish between normal and altered gait (binary classification) and between types of alterations (multi-classes classification). Preliminary results obtained on healthy volunteers simulating alterations are presented and discussed
Marble consolidation by ammonium phosphate (DAP): Do soluble salts in the substrate interfere with in situ apatite formation?
No full textThe use of aqueous solutions of diammonium hydrogen phosphate (DAP) to form hydroxyapatite (HAP) in situ, on the surface and inside the pores and cracks in heritage building materials (e.g. stones, mortars, frescoes, stuccoes), is receiving increasing attention, because of the advantages that this method offers compared to alternative treatments. However, heritage substrates are often affected by the presence of soluble salts when conservation treatments are applied, which can interfere with the expected chemical reactions. Therefore, the present study aimed at assessing the effects of three types of salt (NaCl, NaNO3 and Na2SO4) present in a reference type of substrate (marble) when treated with DAP solutions. Marble samples were preliminarily contaminated with increasing amounts of the three salts, to reach levels of contamination that can be regarded as low, medium and high according to existing standards. Then, the salt-contaminated samples were consolidated by treatment with a solution containing 1 M DAP+ 1 mM CaCl2, applied by poultice. The possible interference of foreign ions deriving from salt dissolution on in situ HAP formation was investigated by XRD and SEM-EDS, aimed at assessing whether ionic substitutions in the HAP crystal occurred and/or foreign ions were adsorbed onto the new phases. The results of the study indicate that, independently of the initial salt content, HAP and/or carbonate HAP (containing CO32- ions from the substrate and from the atmosphere) were formed. These new phases proved to be resistant to accelerated ageing, consisting in immersion in water for 24 h. Therefore, the presence of NaCl, NaNO3 and Na2SO4 (even in high amounts, corresponding to high risk) was found not to negatively affect the outcome of the DAP treatment in the conditions investigated in this study
Enhancing Model Generalizability In Parkinson's Disease Automatic Assessment: A Semi-Supervised Approach Across Independent Experiments
Full text linkMachine learning in Parkinson's disease assessment uses data from clinically-coded movements, such as finger tapping, to objectively measure motor impairment. Video-based models showed promise in several experiments, but the lack of a unified test benchmark hinders proving generalizability. Additionally, new telemedicine systems may easily collect large amounts of unsupervised data, while obtaining ground truth labels for supervised learning remains time-consuming and requires specialized clinicians. This study explores semi-supervised learning to enhance the generalizability of a Light Gradient Boosting model for video-based finger tapping staging, while reducing its need for supervised data labelling. Specifically, this work employs the Self-training schema in two trials using openly-available finger tapping datasets from three independent experiments. This method significantly improves model performance across various metrics, achieving notable accuracy gains (e.g., from 87.62% to 92.05%) when tested on unseen data from a different experiment. Semi-supervision proves valuable when limited labelled data (less than 10%) from the test distribution are available during training
Does Baseline Stress Affect Electrodermal Activity? A Serious-Game-Based Pilot Study
No full textStress management is crucial for health and well being. Electrodermal activity (EDA) is a promising physiological marker for studying stress. While the detection of stress response to stimuli in the short term using EDA is well-studied, the impact of baseline stress (i.e. averaged daily life stress perceived on the long period) on EDA remains unexplored. This study combines a serious game for stress induction, with simultaneous EDA recording to investigate the relation between baseline stress and the EDA response obtained during gameplay. In a pilot study involving 25 university students, EDA features had moderate correlation (Spearman's ρs ≥0.4, p-value <0.05) with stress perceived by the subject in the previous month and differed significantly between low and moderate baseline stress groups. As a further analysis, shallow learning models trained on EDA features to recognize these two groups achieved ≥ 90.0% accuracy and F1-score in a Leave-One-Subject-Out validation, supporting the initial hypothesis that baseline stress directly affects subjects' EDA
Electrodermal Activity in the Evaluation of Engagement for Telemedicine Applications
Full text linkElectrodermal Activity (EDA) is a broadly-investigated physiological signal, whose behaviour is connected to nervous system arousal. Such system, indeed, influences the properties of the skin, producing a measurable electrical signal. Among the possible applications of such measurements, several studies have correlated the signal behaviour to engagement during mental and physical tasks, and the subjects' response to specific multimodal stimuli. Also due to the possibility of performing remote assessment and rehabilitation, telemedicine applications are gaining ground in the healthcare system. However, acceptance and engagement, hence continuity of usage, still remain significant obstacles. Therefore, it would be highly beneficial to verify, through objective measures, if these solutions are actually providing a sufficient stimulation to properly engage subjects while playing. This study investigates the possibility of employing EDA in the automatic recognition of different levels of user engagement, while playing a motor-cognitive exergame specifically designed for this purpose. Preliminary results, obtained on a cohort of 25 healthy subjects, seem to confirm that features extracted from EDA analysis are significant and able to train supervised classifiers, achieving high accuracy and precision in the engagement recognition problem
Corrosion Behavior of Aluminum Alloys in Different Alkaline Environments: Effect of Alloying Elements and Anodization Treatments
Full text linkAluminum alloys are extensively used to manufacture mechanical components. However, when exposed to alkaline environments, like lubricants, refrigerants, or detergents, they can be corroded, reducing their durability. For this reason, the aim of this study is to investigate the influence of aggressive alkaline solutions (i.e., pH and presence of chlorides) on the corrosion resistance of three aluminum alloys (AA 5083-H111, AA 6082-T6, and AA 7075-T6) with and without anodizing treatments. Open circuit potential (EOCP) and anodic polarization measurements were carried out and typical corrosion parameters such as corrosion current density (icor) and corrosion rate (CR) were determined. Morphology of the corrosion attack and samples microstructure were investigated by scanning electron microscope. Results show that corrosion behavior of the three investigated alloys is influenced by (i) the aggressiveness of the testing environments; (ii) the thickness of the anodizing treatment; (iii) the alloy chemical composition; (iv) the distribution of intermetallic phases in the aluminum matrix. Moreover, three galvanic series have been built also testing other metallic alloys commonly used in mechanical applications, i.e., carbon steel (C40), stainless-steel (AISI 304), and Cu-based alloys (Cu-Ni alloy and CW 617 N, respectively). Results clearly indicate that galvanic series play a fundamental role when it is necessary to select an alloy for a specific environment, highlighting the thermodynamic conditions for corrosion occurrence. On the other hand, kinetic measurements and microstructural studies carried out on the three aluminum alloys stress the importance of the surface treatments and relevant thickness as well as the effect of metal exposure. Future work will involve the study of other surface treatments on aluminum alloys and the evaluation of their corrosion behavior in acidic environments
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