28 research outputs found
A novel chemo-optogenetic nanomachine sensitive to intracellular pH shifts
No full textEpilepsy is a neurological disorder characterized by repeated seizures. Nowadays drugs and other approaches to reduce them are available but, unfortunately, around 30% of patients do not respond to medical therapies. In the last decade, optogenetics has emerged as a tool to both explore neuronal networks dynamics and to treat neurological conditions such as epilepsy. The optogenetics strategy involves the expression, in precise brain areas, of light sensitive proteins called opsins that are able to change the membrane potential upon wavelength-specific illumination. This last aspect is, usually, achieved using LED-based hardware. Despite the many advantages of this technique, it still faces practical and translational challenges because of the difficulties of illuminating multiple and deep areas of the brain. In this scenario, the search of alternative light sources is a goal to achieve. Luciferases are enzymes able to emit light upon addiction of their own substrate coelenterazine, and can be used to deliver light to opsins and modulate their action. In this work, the probe called pHIL (pH sensitive inhibitory luminopsin) was developed with the purpose to modulate the epileptic phenotype. pHIL is composed by a bioluminescent protein, RLuc8, coupled to the inhibitory opsin eNpHR3.0. Moreover, the control of seizures will occur only under the intracellular acidic conditions observed in epileptic neurons. The pH sensitivity of the probe is given by the presence of a pH sensor, a pH-sensitive variant of EGFP, called E2GFP. The functioning of the probe is based on the BRET mechanism. The UV light that comes from the luciferase is transferred to the E2GFP that under acidic conditions will emit light and activate the eNpHR3.0, promoting membrane hyperpolarization of epileptic neurons. pHIL is expressed and localizes at the plasma membrane in both HEK293T cells and primary hippocampal neurons. Moreover, pHIL hyperpolarizes HEK293T under acidic conditions and upon addiction of CTZ 400a, the specific luciferase substrate able to induce the UV light emission. On the basis of our data, therefore, we propose pHIL as a potential therapeutic tool to counteract neuronal hyperexcitability
Correction to: Pediatric elbow arthroscopy: clinical outcomes and complications after long-term follow-up (Journal of Orthopaedics and Traumatology, (2021), 22, 1, (55), 10.1186/s10195-021-00619-2)
No full textFollowing publication of the original article [1], the authors identified an error in the author names. The given name and family name were erroneously transposed. The incorrect author names: Micheloni Gian Mario, Tarallo Luigi, Negri Alberto, Giorgini Andrea, Merolla Giovanni and Porcellini Giuseppe. The correct author names: Gian Mario Micheloni, Luigi Tarallo, Alberto Negri, Andrea Giorgini, Giovanni Merolla, Giuseppe Porcellini. The author group has been updated above and the original article [1] has been corrected
Benign chondroblastoma on fine-needle aspiration smears: A seven-case experience and review of the literature
No full textWe report seven cases of chondroblastoma (CB) of bone, diagnosed by Fine-Needle Aspiration Cytology (FNAC), and confirmed by histomorphological examination. The concurrence of some cytomorphologic findings - mononucleated cells, multinucleated cells, and intercellular chondroid substance - unequivocally suggested the cytological diagnosis of CB. We also reviewed the literature on this topic in order to discuss morphological criteria and the importance of needle size. The differential diagnosis between CB, Giant Cell Tumor of Bone, and Eosinophilic Granuloma is further discussed
Simone Varriale, Globalization, Music and Cultures Of Distinction, The Rise of Pop Music Criticism in Italy, London, Palgrave Macmillan, 2016
No full textThis review - of the volume by Simone Varriale, Globalization, Music and Cultures Of Distinction, The Rise of Pop Music Criticism in Italy, London, Palgrave Macmillan, 2016- focuses on the rise of Italian pop music criticism as a new cultural institution which, according to the author, contributed to the “artistic legitimation” of popular music and culture between 1969 and 1977, particularly of American and British pop-rock in Italy. It is a study which, using an interdisciplinary approach, also aims to promote an historical research about the rise of the Italian music press
Engineering REST-Specific Synthetic PUF Proteins to Control Neuronal Gene Expression: A Combined Experimental and Computational Study
No full textRegulation of gene transcription is an essential mechanism for differentiation and adaptation of organisms. A key actor in this regulation process is the repressor element 1 (RE1)-silencing transcription factor (REST), a transcriptional repressor that controls more than 2000 putative target genes most of which are neuron-specific. With the purpose of modulating REST expression, we exploited synthetic, ad hoc designed, RNA Binding Proteins (RBPs) able to specifically target and dock to REST mRNA. Amongst the various families of RBPs, we focused on the Pumilio and FBF (PUF) proteins, present in all eukaryotic organisms and controlling a variety of cellular functions. Here, a combined experimental and computational approach was used to design and test 8- and 16-repeat PUF proteins specific for REST mRNA. We explored the conformational properties and atomic features of the PUF-RNA recognition code by Molecular Dynamics simulations. Biochemical assays revealed that the 8- and 16-repeat PUF-based variants specifically bind the endogenous REST mRNA without affecting its translational regulation. The data also indicate a key role of stacking residues in determining the binding specificity. The newly characterized REST-specific PUF-based constructs act as excellent RNA-binding modules and represent a versatile and functional platform to specifically target REST mRNA and modulate its endogenous expression
‐deoxy‐coelenterazine Derivatives and Their Potential Use as Cellular pH Probes
No full textThe synthesis of new bis-deoxy-coelenterazine (1) derivatives bearing ester protective groups (acetate, propionate and butyrate esters) was accomplished. Moreover, their hydrolytic stability at room temperature was evaluated in dimethylsulfoxide (DMSO) as solvent, using the nuclear magnetic resonance (NMR) spectra of the key products at different time intervals. The results showed an increasing hydrolysis rate according to longest aliphatic chain, with a half-life of 24 days of the more stable acetate derivative (4a). Furthermore, the analysis of the experimental data revealed the greater stability of the enol tautomer in this aprotic polar solvent. This result was confirmed by theoretical calculations using the density functional theory (DFT) approach, which gave us the opportunity to propose a detailed decomposition mechanism. Additionally, the derivatives obtained were tested by bioluminescence luciferase assays to evaluate their potential use as extracellular pH-sensitive reporter substrates of luciferase. The biological data support the idea that further structural modifications of these molecules may open promising perspectives in this field of research. © 2020 American Society for Photobiolog
Surgical treatment of chronic acromioclavicular dislocation with biologic graft vs synthetic ligament: a prospective randomized comparative study
Get PDFBackground: Acromioclavicular (AC) dislocation involves complete loss of articular contact; it is defined as chronic when it follows conservative management or unsuccessful surgical treatment. Materials and methods: The study compared the clinical and radiographic outcomes of AC joint stabilization performed in 40 patients with chronic dislocation using a biological allograft (group A) or a synthetic ligament (group B). Demographic data included: M/F: 25/15; mean age: 35 ± 3.2 years; previous surgery in 11 patients, including Weaver-Dunn (3), coracoacromial ligament repair (4), stabilization with K-wires (4). Dislocation was type III in 14 (35 %) and type IV in 26 (65 %) patients. Clinical assessment was with the Constant-Murley score (pre- and postoperative) and with the modified UCLA score. Enrollment started in January 2004 and was completed in March 2008. Patients were evaluated at 1 and 4 years. Postoperative X-rays were examined to assess joint stability in the coronal and axial planes, coracoclavicular ossification, and signs of AC joint osteoarthritis and distal clavicular osteolysis. Results: The "biological" group achieved significantly better clinical scores than the "synthetic" group at both 1 and 4 years. Poor subjective satisfaction and lower clinical scores were found in the 3 patients (1 from group A and 2 from group B) who experienced complete postoperative dislocation. No significant correlations were found with other radiographic parameters. Conclusions: The biological graft afforded better clinical and radiographic outcomes than the synthetic ligament in patients with chronic AC joint instability. Fixation to the clavicle constitutes the main weakness of both approaches and needs improving. © 2012 The Author(s)
Arthroscopic treatment of early glenohumeral arthritis
Get PDFBackground: The articular cartilage of the shoulder is not endowed with intrinsic repair abilities, so the detection of chondral lesions during arthroscopy may indicate that additional articular procedures are needed. The aim of the current study was to evaluate the benefits of arthroscopy in patients with early shoulder arthritis, and to assess which clinical and radiological features are correlated with better arthroscopic outcomes. Materials and methods: Out of a total of 2,707 shoulders, 61 arthroscopies were performed on patients aged 30-55 years suffering from a painful early arthritic shoulder. We performed a retrospective study of 47 of those 61 patients with osteoarthritis at Samilson-Prieto stage I or II. SST and Constant score were used as outcome measures. Arthroscopic circumferential capsulotomy was performed to release the soft tissues and increase the joint space. Glenoid chondral lesions were caregorized according to location (anterior, posterior, centered) and size (small, large, total) and treated with microfractures; in the last 11 patients, we placed a engineered hyaluronic acid membrane, Hyalograft® C, on the surface of the glenoid. Postoperative care included mobilization the day after surgery, with the arm protected in a sling for two weeks. Follow-up examinations were performed at 3, 6, 12, and 24 months after surgery. The clinical and radiographic data collected were compared with those obtained at the last examination. Results: The mean Constant score increased from 43.8 points to 79.1, and the mean SST score increased from 4.9 points to 9.4 points. Clinical outcomes improved significantly in 44 patients (93.6 %). The three patients (6.4 %) with the lowest scores showed progression of arthritis. Age, gender, glenohumeral distance, and presence of engineered hyaluronic acid membrane were not related to clinical scores. Recovery of range of motion as well as small and centered cartilage lesions were statistically associated with improved outcome. Conclusion: The main finding was that soft tissue procedures (including capsulotomy and synovectomy) associated with glenoid microfractures are only suitable for patients with early arthritis and preserved humeral head shape, particularly in cases with small and centered glenoid cartilage lesions. © 2012 The Author(s)
GENDER AND COMMUNITY IN THE ORAL AND IN THE WRITTEN
Get PDFInternational audienceThe central question addressed in this paper is how categories of gender and community affect each other (1). This question is looked at in one of the preferred fields for intellectual constructions and interpretations, that of literary narratives. The relationship between gender and community is examined in a corpus of Kabyle oral narratives and in novels written in French by women writers from Kabylia (Algeria). These genres are heterogeneous in mode of production (oral, written) and language (Kabyle, French), but they can be included in what the author calls a 'Kabyle literary space', which permits a recognition of the interactions and intersections of materials that cannot be understood, interpreted, or even enjoyed were they to belong to two discrete systems
A pH-sensitive closed-loop nanomachine to control hyperexcitability at the single neuron level
No full textEpilepsy affects 1% of the general population and 30% of patients are resistant to antiepileptic drugs. Although optogenetics is an efficient antiepileptic strategy, the difficulty of illuminating deep brain areas poses translational challenges. Thus, the search of alternative light sources is strongly needed. Here, we develop pH-sensitive inhibitory luminopsin (pHIL), a closed-loop chemo-optogenetic nanomachine composed of a luciferase-based light generator, a fluorescent sensor of intracellular pH (E2GFP), and an optogenetic actuator (halorhodopsin) for silencing neuronal activity. Stimulated by coelenterazine, pHIL experiences bioluminescence resonance energy transfer between luciferase and E2GFP which, under conditions of acidic pH, activates halorhodopsin. In primary neurons, pHIL senses the intracellular pH drop associated with hyperactivity and optogenetically aborts paroxysmal activity elicited by the administration of convulsants. The expression of pHIL in hippocampal pyramidal neurons is effective in decreasing duration and increasing latency of pilocarpine-induced tonic-clonic seizures upon in vivo coelenterazine administration, without affecting higher brain functions. The same treatment is effective in markedly decreasing seizure manifestations in a murine model of genetic epilepsy. The results indicate that pHIL represents a potentially promising closed-loop chemo-optogenetic strategy to treat drug-refractory epilepsy
