57 research outputs found

    A Three-Layers Theoretical Framework For Analyzing Public Private Partnerships: The Italian Case

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    The applications of PPP all over the world vary from country to country. International literature lacks of contributions focusing on cross-country and cross-sector description, analysis and comparison of Public Private Partnerships (PPPs). The present paper aims at developing a framework for characterizing PPPs in various countries. The theoretical framework is divided in three layers: country, sector and project layers. Each layer is characterized by a set of dimensions and each dimension is characterized by a set of variables that are highly relevant to characterize PPPs. The proposed framework has been applied to characterize PPPs implementation in Italy, with a particular focus on the transport sector

    In vivo evaluation of antimyotonic efficacy of β-adrenergic drugs in a rat model of myotonia

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    AbstractThe sodium channel blocker mexiletine is considered the first-line drug in myotonic syndromes, a group of muscle disorders characterized by membrane over-excitability. We previously showed that the β-adrenoceptor modulators, clenbuterol and propranolol, block voltage-gated sodium channels in a manner reminiscent to mexiletine, whereas salbutamol and nadolol do not. We now developed a pharmacological rat model of myotonia congenita to perform in vivo preclinical test of antimyotonic drugs. Myotonia was induced by i.p. injection of 30 mg/kg of anthracene-9-carboxylic acid (9-AC), a muscle chloride channel blocker, and evaluated by measuring the time of righting reflex (TRR). The TRR was prolonged from <0.5 s in control conditions to a maximum of ∼4 s, thirty minutes after 9-AC injection, then gradually recovered in a few hours. Oral administration of mexiletine twenty minutes after 9-AC injection significantly hampered the TRR prolongation, with an half-maximum efficient dose (ED50) of 12 mg/kg. Both propranolol and clenbuterol produced a dose-dependent antimyotonic effect similar to mexiletine, with ED50 values close to 20 mg/kg. Antimyotonic effects of 40 mg/kg mexiletine and propranolol lasted for 2 h. We also demonstrated, using patch-clamp methods, that both propranolol enantiomers exerted a similar block of skeletal muscle hNav1.4 channels expressed in HEK293 cells. The two enantiomers (15 mg/kg) also showed a similar antimyotonic activity in vivo in the myotonic rat. Among the drugs tested, the R(+)-enantiomer of propranolol may merit further investigation in humans, because it exerts antimyotonic effect in the rat model, while lacking of significant activity on the β-adrenergic pathway. This study provides a new and useful in vivo preclinical model of myotonia congenita in order to individuate the most promising antimyotonic drugs to be tested in humans

    Synergism Between Immunotherapy and Radiotherapy in Esophageal Cancer: An Overview of Current Knowledge and Future Perspectives

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    Background: Esophageal cancer (EC) is an aggressive neoplasm of the gastrointestinal tract that is usually treated with a combination of chemotherapy, radiotherapy (RT), and/or surgery, according to disease status. Despite the availability of multimodal therapeutic strategies, local recurrence is frequently observed. Immunotherapy is a promising therapeutic approach that is currently highly investigated in association to standard therapies, including RT, with the aim to improve patients' outcomes. Materials and Methods: A PubMed search was performed with the following keywords in all fields: "esophageal cancer" and "radiotherapy" and "radiation" and "immunotherapy" and "PD-1" and "PD L1." For an overview of ongoing trials, an additional search on ClinicalTrials.gov website was performed using the keywords "esophageal cancer" and "immunotherapy" and "PD-L1" and "CTLA-4" and "radiation" and "radiotherapy." Emerging data from preclinical and clinical studies are suggesting a synergistic effect between immunotherapy and RT. With the aim to update the knowledge of this synergistic immune-mediated antitumor activity and discuss current challenges, the authors summarize published data concerning the basic mechanisms and the effectiveness and tolerance of the combination between immunotherapy and RT for patients with EC, followed by an overview of ongoing clinical trial. Conclusions: Published results encourage the use of personalized therapeutic approaches for EC patients in the future; results from ongoing studies will help to identify the optimal strategies for patient selection and treatment response evaluation

    Inhibition of voltage-gated sodium channels by sumatriptan bioisosteres

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    Voltage-gated sodium channels are known to play a pivotal role in perception and transmission of pain sensations. Gain-of-function mutations in the genes encoding the peripheral neuronal sodium channels, hNav1.7-1.9, cause human painful diseases. Thus while treatment of chronic pain remains an unmet clinical need, sodium channel blockers are considered as promising druggable targets. In a previous study, we evaluated the analgesic activity of sumatriptan, an agonist of serotonin 5HT1B/D receptors, and some new chiral bioisosteres, using the hot plate test in the mouse. Interestingly, we observed that the analgesic effectiveness was not necessarily correlated to serotonin agonism. In this study, we evaluated whether sumatriptan and its congeners may inhibit heterologously expressed hNav1.7 sodium channels using the patch-clamp method. We show that sumatriptan blocks hNav1.7 channels only at very high, supratherapeutic concentrations. In contrast, its three analogs, namely 20b, (R)-31b, and (S)-22b, exert a dose and use-dependent sodium channel block. At 0.1 and 10 Hz stimulation frequencies, the most potent compound, (S)-22b, was 4.4 and 1.7 fold more potent than the well-known sodium channel blocker mexiletine. The compound induces a negative shift of voltage dependence of fast inactivation, suggesting higher affinity to the inactivated channel. Accordingly, we show that (S)-22b likely binds the conserved local anesthetic receptor within voltage-gated sodium channels. Combining these results with the previous ones, we hypothesize that use-dependent sodium channel blockade contributes to the analgesic activity of (R)-31b and (S)-22b. These later compounds represent promising lead compounds for the development of efficient analgesics, the mechanism of action of which may include a dual action on sodium channels and 5HT1D receptors

    Adding Concomitant Chemotherapy to Postoperative Radiotherapy in Oral Cavity Carcinoma with Minor Risk Factors: Systematic Review of the Literature and Meta-Analysis

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    Simple Summary Oral cavity carcinoma (OCC) is the 11th most frequently diagnosed cancer; despite a multimodal treatment, locally advanced OCC, managed by surgery and adjuvant therapies, remains at high risk of recurrence, with a 5-year overall survival (OS) of 51%. The efficacy of postoperative chemotherapy in addition to radiotherapy (POCRT) in low-intermediate risk OCC is a controversial matter in the absence of high-risk features (ENE, R1). To establish the role of POCRT in a population with solely minor risk factors (perineural invasion or lymph vascular invasion; pN1 single; DOI &gt;= 5 mm; close margin; node-positive level IV or V; pT3 or pT4; multiple lymph nodes without ENE), we performed a systematic review and meta-analyses focused on OS, disease-free survival (DFS), and local-recurrence-free survival (LRFS). Thirteen studies met the inclusion criteria and were included in the quantitative meta-analyses. Our preliminary results are in favor of POCRT in terms of OS but not conclusive for DFS and LRFS. Further analyses are suggested. When presenting with major pathological risk factors, adjuvant radio-chemotherapy for oral cavity cancers (OCC) is recommended, but the addition of chemotherapy to radiotherapy (POCRT) when only minor pathological risk factors are present is controversial. A systematic review following the PICO-PRISMA methodology (PROSPERO registration ID: CRD42021267498) was conducted using the PubMed, Embase, and Cochrane libraries. Studies assessing outcomes of POCRT in patients with solely minor risk factors (perineural invasion or lymph vascular invasion; pN1 single; DOI &gt;= 5 mm; close margin &lt; 2-5 mm; node-positive level IV or V; pT3 or pT4; multiple lymph nodes without ENE) were evaluated. A meta-analysis technique with a single-arm study was performed. Radiotherapy was combined with chemotherapy in all studies. One study only included patients treated with POCRT. In the other 12 studies, patients were treated with only PORT (12,883 patients) and with POCRT (10,663 patients). Among the patients treated with POCRT, the pooled 3 year OS rate was 72.9% (95%CI: 65.5-79.2%); the pooled 3 year DFS was 70.9% (95%CI: 48.8-86.2%); and the pooled LRFS was 69.8% (95%CI: 46.1-86.1%). Results are in favor of POCRT in terms of OS but not significant for DFS and LRFS, probably due to the heterogeneity of the included studies and a combination of different prognostic factors

    Translational approach to address therapy in myotonia permanens due to a new SCN4A mutation

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    Objective: We performed a clinical, functional, and pharmacologic characterization of the novel p.P1158L Nav1.4 mutation identified in a young girl presenting a severe myotonic phenotype. Methods: Wild-type hNav1.4 channel and P1158L mutant were expressed in tsA201 cells for functional and pharmacologic studies using patch-clamp. Results: The patient shows pronounced myotonia, slowness of movements, and generalized muscle hypertrophy. Because of general discomfort with mexiletine, she was given flecainide with satisfactory response. In vitro, mutant channels show a slower current decay and a rightward shift of the voltage dependence of fast inactivation. The voltage dependence of activation and slow inactivation were not altered. Mutant channels were less sensitive to mexiletine, whereas sensitivity to flecainide was not altered. The reduced inhibition of mutant channels by mexiletine was also observed using clinically relevant drug concentrations in a myotonic-like condition. Conclusions: Clinical phenotype and functional alterations of P1158L support the diagnosis of myotonia permanens. Impairment of fast inactivation is consistent with the possible role of the channel domain III S4-S5 loop in the inactivation gate docking site. The reduced sensitivity of P1158L to mexiletine may have contributed to the unsatisfactory response of the patient. The success of flecainide therapy underscores the usefulness of in vitro functional studies to help in the choice of the best drug for each individual

    Molecular Insights into the Local Anesthetic Receptor within Voltage-Gated Sodium Channels Using Hydroxylated Analogs of Mexiletine

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    We previously showed that the β-adrenoceptor modulators, clenbuterol and propranolol, directly blocked voltage-gated sodium channels, whereas salbutamol and nadolol did not (Desaphy et al., 2003), suggesting the presence of two hydroxyl groups on the aromatic moiety of the drugs as a molecular requisite for impeding sodium channel block. To verify such an hypothesis, we synthesized five new mexiletine analogs by adding one or two hydroxyl groups to the aryloxy moiety of the sodium channel blocker and tested these compounds on hNav1.4 channels expressed in HEK293 cells. Concentration–response relationships were constructed using 25-ms-long depolarizing pulses at −30 mV applied from an holding potential of −120 mV at 0.1 Hz (tonic block) and 10 Hz (use-dependent block) stimulation frequencies. The half-maximum inhibitory concentrations (IC50) were linearly correlated to drug lipophilicity: the less lipophilic the drug, minor was the block. The same compounds were also tested on F1586C and Y1593C hNav1.4 channel mutants, to gain further information on the molecular interactions of mexiletine with its receptor within the sodium channel pore. In particular, replacement of Phe1586 and Tyr1593 by non-aromatic cysteine residues may help in the understanding of the role of π–π or π–cation interactions in mexiletine binding. Alteration of tonic block suggests that the aryloxy moiety of mexiletine may interact either directly or indirectly with Phe1586 in the closed sodium channel to produce low-affinity binding block, and that this interaction depends on the electrostatic potential of the drug aromatic tail. Alteration of use-dependent block suggests that addition of hydroxyl groups to the aryloxy moiety may modify high-affinity binding of the drug amine terminal to Phe1586 through cooperativity between the two pharmacophores, this effect being mainly related to drug lipophilicity. Mutation of Tyr1593 further impaired such cooperativity. In conclusion, these results confirm our former hypothesis by showing that the presence of hydroxyl groups to the aryloxy moiety of mexiletine greatly reduced sodium channel block, and provide molecular insights into the intimate interaction of local anesthetics with their receptor

    Combined Modifications of Mexiletine Pharmacophores for New Lead Blockers of Nav1.4 Channels

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    AbstractPreviously identified potent and/or use-dependent mexiletine (Mex) analogs were used as template for the rational design of new Nav-channel blockers. The effects of the novel analogs were tested on sodium currents of native myofibers. Data and molecular modeling show that increasing basicity and optimal alkyl chain length enhance use-dependent block. This was demonstrated by replacing the amino group with a more basic guanidine one while maintaining a proper distance between positive charge and aromatic ring (Me13) or with homologs having the chirality center nearby the amino group or the aromatic ring. Accordingly, a phenyl group on the asymmetric center in the homologated alkyl chain (Me12), leads to a further increase of use-dependent behavior versus the phenyl Mex derivative Me4. A fluorine atom in paraposition and one ortho-methyl group on the xylyloxy ring (Me15) increase potency and stereoselectivity versus Me4. Charge delocalization and greater flexibility of Me15 may increase its affinity for Tyr residues influencing steric drug interaction with the primary Phe residue of the binding site. Me12 and Me15 show limited selectivity against Nav-isoforms, possibly due to the highly conserved binding site on Nav. To our knowledge, the new compounds are the most potent Mex-like Nav blockers obtained to date and deserve further investigation

    On driver behavior recognition for increased safety:A roadmap

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    Advanced Driver-Assistance Systems (ADASs) are used for increasing safety in the automotive domain, yet current ADASs notably operate without taking into account drivers’ states, e.g., whether she/he is emotionally apt to drive. In this paper, we first review the state-of-the-art of emotional and cognitive analysis for ADAS: we consider psychological models, the sensors needed for capturing physiological signals, and the typical algorithms used for human emotion classification. Our investigation highlights a lack of advanced Driver Monitoring Systems (DMSs) for ADASs, which could increase driving quality and security for both drivers and passengers. We then provide our view on a novel perception architecture for driver monitoring, built around the concept of Driver Complex State (DCS). DCS relies on multiple non-obtrusive sensors and Artificial Intelligence (AI) for uncovering the driver state and uses it to implement innovative Human–Machine Interface (HMI) functionalities. This concept will be implemented and validated in the recently EU-funded NextPerception project, which is briefly introduced

    Increased sodium channel use-dependent inhibition by a new potent analogue of tocainide greatly enhances in&nbsp;vivo antimyotonic activity

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    Although the sodium channel blocker, mexiletine, is the first choice drug in myotonia, some myotonic patients remain unsatisfied due to contraindications, lack of tolerability, or incomplete response. More therapeutic options are thus needed for myotonic patients, which require clinical trials based on solid preclinical data. In previous structure-activity relationship studies, we identified two newly-synthesized derivatives of tocainide, To040 and To042, with greatly enhanced potency and use-dependent behavior in inhibiting sodium currents in frog skeletal muscle fibers. The current study was performed to verify their potential as antimyotonic agents. Patch-clamp experiments show that both compounds, especially To042, are greatly more potent and use-dependent blockers of human skeletal muscle hNav1.4 channels compared to tocainide and mexiletine. Reduced effects on F1586C hNav1.4 mutant suggest that the compounds bind to the local anesthetic receptor, but that the increased hindrance and lipophilia of the N-substituent may further strengthen drug-receptor interaction and use-dependence. Compared to mexiletine, To042 was 120 times more potent to block hNav1.4 channels in a myotonia-like cellular condition and 100 times more potent to improve muscle stiffness in&nbsp;vivo in a previously-validated rat model of myotonia. To explore toxicological profile, To042 was tested on hERG potassium currents, motor coordination using rotarod, and C2C12&nbsp;cell line for cytotoxicity. All these experiments suggest a satisfactory therapeutic index for To042. This study shows that, owing to a huge use-dependent block of sodium channels, To042 is a promising candidate drug for myotonia and possibly other membrane excitability disorders, warranting further preclinical and human studies
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