Muscle biopsy and cell cultures: potential diagnostic tools in hereditary skeletal muscle channelopathies.

Hereditary muscle channelopathies are caused by dominant mutations in the genes encoding for subunits of muscle voltage- gated ion channels. Point mutations on the human skeletal muscle Na+ channel (Nav1.4) give rise to hyperkalemic periodic paralysis, potassium aggravated myotonia, paramyotonia congenita and hypokalemic periodic paralysis type 2. Point mutations on the human skeletal muscle Ca2+ channel give rise to hypokalemic periodic paralysis and malignant hyperthermia. Point mutations in the human skeletal chloride channel ClC-1 give rise to myotonia congenita. Point mutations in the inwardly rectifying K+ channel Kir2.1 give rise to a syndrome characterized by periodic paralysis, severe cardiac arrhythmias and skeletal alterations (Andersen's syndrome). Involvement of the same ion channel can thus give rise to different phenotypes. In addition, the same mutation can lead to different phenotypes or similar phenotypes can be caused by different mutations on the same or on different channel subtypes. Bearing in mind, the complexity of this field, the growing number of potential channelopathies (such as the myotonic dystrophies), and the time and cost of the genetic procedures, before a biomolecular approach is addressed, it is mandatory to apply strict diagnostic protocols to screen the patients. In this study we propose a protocol to be applied in the diagnosis of the hereditary muscle channelopathies and we demonstrate that muscle biopsy studies and muscle cell cultures may significantly contribute towards the correct diagnosis of the channel involved. DNAbased diagnosis is now a reality for many of the channelopathies. This has obvious genetic counselling, prognostic and therapeutic implications

Monitoring Composites under Bending Tests with Infrared Thermography

The attention of the present paper is focused on the use of an infrared imaging device to monitor the thermal response of composite materials under cyclic bending. Three types of composites are considered including an epoxy matrix reinforced with either carbon fibres (CFRP) or glass fibres (GFRP) and a hybrid composite involving glass fibres and aluminium layers (FRML). The specimen surface, under bending, displays temperature variations pursuing the load variations with cooling down under tension and warming up under compression; such temperature variations are in agreement with the bending moment. It has been observed that the amplitude of temperature variations over the specimen surface depends on the material characteristics. In particular, the presence of a defect inside the material affects the temperature distribution with deviation from the usual bending moment trend

Porosity Distribution in Composite Structures with Infrared Thermography

Composite structures are increasingly used in the transport industry especially in the aeronautical sector thanks to their favorable strength-to-weight ratio with respect to metals. However, this is true if the final part is defects free and complies with quality requirements. A main weakness in composites is porosity, which is likely to be introduced during manufacturing processes and which may knock down the material characteristics affecting its performance in service. Porosity plays a key role in sandwich structures, which involve novel metal foams as core, since the foam performance strongly depends on size and distribution of pores. The determination of porosity is mostly attained by destructive methods, which supply only a general indication linked to the production part number. Conversely, composites may entail local significant variation of porosity, which may be discovered only with effective nondestructive techniques. The attention of the present work is focused on the possibility to use infrared thermography to get information about the amount and distribution of porosity. In particular, two techniques: flash thermography and lock-in thermography are used to comply with requirements of both monolithic composites and metal foams

Biomolecular identification of (CCTG)n mutation in myotonic dystrophy type 2 (DM2) by FISH on muscle biopsy

Myotonic dystrophy type 2 (DM2) is a dominantly inherited disorder with multisystemic clinical features, caused by a CCTG repeat expansion in intron 1 of the zinc finger protein 9 (ZNF9) gene. The mutant transcripts are retained in the nucleus forming multiple discrete foci also called ribonuclear inclusions. The size and the somatic instability of DM2 expansion complicate the molecular diagnosis of DM2. In our study fluorescence-labeled CAGG-repeat oligonucleotides were hybridized to muscle biopsies to investigate if fluorescence in situ hybridization (FISH), a relatively quick and simple procedure, could be used as a method to diagnose DM2. When FISH was performed with (CAGG)5 probe, nuclear foci of mutant RNA were present in all genetically confirmed DM2 patients (n = 17) and absent in all patients with myotonic dystrophy type 1 (DM1; n = 5) or with other muscular disease (n = 17) used as controls. In contrast, foci were observed both in DM1 and DM2 myonuclei when muscle tissue were hybridized with (CAG)6CA probe indicating that this probe is not specific for DM2 identification. The consistent detection of ribonuclear inclusions in DM2 muscles and their absence in DM1, in agreement with the clinical diagnosis and with leukocyte (CCTG)n expansion, suggests that fluorescence in situ hybridization using (CAGG)5 probes, may be a specific method to distinguish between DM1 and DM2. Moreover, the procedure is simple, and readily applicable in any pathology laboratory

Visualization of Thermal Effects in Polypropylene-based Composites under Cyclic Bending Tests☆

Abstract The attention of this paper is focused on surface temperature changes which are experienced by thermoplastic composite materials under cyclic bending tests. Such changes are visualized and measured with an infrared imaging device and later analyzed to gain information which, coupled with other mechanical and/or chemical properties, may be exploited for the material characterization. In particular, thermoplastic composites based on a polypropylene matrix, which may be neat, or modified by the addition of a relatively low amount of a specific compatibilizing agent, and reinforced with glass or jute woven fibres are investigated

High-throughput analysis of the RNA-induced silencing complex in myotonic dystrophy type 1 patients identifies the dysregulation of miR-29c and its target ASB2

Myotonic dystrophy type 1 (DM1) is a multi-systemic disorder caused by abnormally expanded stretches of CTG DNA triplets in the DMPK gene, leading to mutated-transcript RNA-toxicity. MicroRNAs (miRNAs) are short non-coding RNAs that, after maturation, are loaded onto the RISC effector complex that destabilizes target mRNAs and represses their translation. In DM1 muscle biopsies not only the expression, but also the intracellular localization of specific miRNAs is disrupted, leading to the dysregulation of the relevant mRNA targets. To investigate the functional alterations of the miRNA/target interactions in DM1, we analyzed by RNA-sequencing the RISC-associated RNAs in skeletal muscle biopsies derived from DM1 patients and matched controls. The mRNAs found deregulated in DM1 biopsies were involved in pathways and functions relevant for the disease, such as energetic metabolism, calcium signaling, muscle contraction and p53-dependent apoptosis. Bioinformatic analysis of the miRNA/mRNA interactions based on the RISC enrichment profiles, identified 24 miRNA/mRNA correlations. Following validation in 21 independent samples, we focused on the couple miR-29c/ASB2 because of the role of miR-29c in fibrosis (a feature of late-stage DM1 patients) and of ASB2 in the regulation of muscle mass. Luciferase reporter assay confirmed the direct interaction between miR-29c and ASB2. Moreover, decreased miR-29c and increased ASB2 levels were verified also in immortalized myogenic cells and primary fibroblasts, derived from biopsies of DM1 patients and controls. CRISPR/Cas9-mediated deletion of CTG expansions rescued normal miR-29c and ASB2 levels, indicating a direct link between the mutant repeats and the miRNA/target expression. In conclusion, functionally relevant miRNA/mRNA interactions were identified in skeletal muscles of DM1 patients, highlighting the dysfunction of miR-29c and ASB2

Cittadinanza attiva e Costituzione

Il percorso formativo si propone di fornire le conoscenze basilari del Diritto costituzionale in una prospettiva di maturazione negli studenti dei fondamenti culturali della cittadinanza attiva, che rappresenta una condizione indispensabile nel processo di sviluppo della persona e nell’ambito delle relazioni sociali, con particolare riguardo a quelle che interessano il contesto del lavoro. Il programma si articolerà in un primo incontro con il coordinatore scientifico Prof. Alberto Lucarelli di impostazione seminariale, in occasione del quale verranno illustrati i principi fondativi del modello di Stato democratico rappresentativo che sono sanciti nella nostra Carta costituzionale. A seguire, verranno realizzati dei moduli laboratoriali su specifici temi che verranno trattati sulla base di un più diretto coinvolgimento degli studenti, attraverso ad esempio simulazioni, realizzazione di mappe concettuali, etc

Sporadic MM-1 Type Creutzfeldt-Jakob Disease With Hemiballic Presentation and No Cognitive Impairment Until Death: How New NCJDRSU Diagnostic Criteria May Allow Early Diagnosis

Sporadic Creutzfeldt-Jakob disease is the most common human prion disorder. Although associated with heterogeneous clinical phenotypes, its distinctive feature is the presence of a rapidly progressive multidomain cognitive impairment. We describe the atypical case of a patient affected by sporadic Methionine/Methionine type 1 Creutzfeldt-Jakob disease (typically associated with early cognitive decline) who presented with an isolated hemiballic syndrome and no signs of cognitive involvement until death. We review sporadic Creutzfeldt-Jakob disease diagnostic criteria and their updates since their first formulation, highlighting their limitations in clinical diagnostic work-up. Finally, we discuss the recently introduced National Creutzfeldt-Jakob Disease Research and Surveillance Unit diagnostic criteria, suggesting how their application could support an early clinical diagnosis, even in atypical cases, such as the one presented

Neuropsychological and psychological functioning aspects in myotonic dystrophy type 1 patients in Italy

Introduction: Myotonic Dystrophy Type 1 (DM1) is an autosomal dominant genetic illness, characterized by a progressive loss of strength. Important deficits in cognitive functioning and a significant prevalence of psychiatric disorders have been previously reported. Methods: A neuropsychological and psychological assessment was carried out in 31 DM1 patients (61% males) in order to measure the cognitive functioning and explore their personality profiles. The MMSE Mini-Mental State Examination, Frontal Assessment Battery (FAB), ENB-2 Battery assessing memory (short term, long term and working memory), integration capacities, visual-spatial ability, attention (selective, divided, shifting/switching) executive functions, praxis, discrimination and logic capabilities and psychopathology Symptom Check List 90-R (SCL-90-R) were administered. The neuropsychological and psychological evaluation of DM1 patients was carried out taking into consideration the clinical parameters (CTG repeat, age at onset, disease duration, Muscular Impairment Rate Scale (MIRS), Medical Research Council Scale (MRC) and the Epworth Sleepiness Scales (EPS)). Results: Regarding psychopathology 19.4% of patients scored a moderate or high level of symptoms intensity index (GSI), 12.9% reported a high number of symptoms (PST) and 16.1% reported a high intensity level of the perceived symptoms (PSDI). Fatigue and daytime sleepiness resulted as being associated with higher levels of psychoticism (PSY). Only 1 patient reported a severe impairment in the spatial and temporal orientation, memory, language, praxis, attention and calculation. Longer disease duration was also associated with cognitive impairment evaluated through ENB-2 (p < 0.05). Discussions and Conclusions: There are indications of the utility of neuropsychological and psychological screening and support for these patients and their families due to the link between disease duration and cognitive performances. A proposal of a clinical protocol, with an illustration of a clinical case report of a family is presented