97 research outputs found

    On the optimality of the yardstick regulation in the presence of dynamic interaction

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    This paper proposes a generalization of Shleifer's (1985) model of yardstick competition, to a dynamic framework. Specifically, we consider a differential game and we show that the yardstick mechanism is effective to replicate the first-best solution if players adopt open-loop behaviour rules and they are symmetric at the initial time; in the absence of initial symmetry, the social efficiency is reached only in the asymptotic steady state. On the contrary, if players adopt Markovian behaviour rules, then the yardstick pricing rule is not able to achieve the first-best solution along the equilibrium path of any Markov Perfect Nash Equilibrium

    Quality competition in healthcare services with regional regulators: A differential game approach

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    This article proposes a differential-game model, in order to analyze markets in which regional regulation is operative and competition is based on quality. The case we have in mind is healthcare public service, where consumers (patients) choose the provider mainly basing on the providers' location and the quality of services, while prices play a more limited role. In most European countries, within the same State, regional (or local) providers compete on quality to attract demand. Market regulation is set at national and/or regional level. Our model highlights the features of equilibrium in such a framework, and specifically investigates how the differences in product quality evolve among regions, and how inter-regional demand flows behave. Differently from some available similar models (that do not take into account the regional dimension of the decision process), we find that quality differentials among regions may persist in equilibrium

    Frequency of Microsatellite Instability in Unselected Sebaceous Gland Neoplasias and Hyperplasias

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    Sebaceous gland neoplasias are the cutaneous manifestation of the Muir–Torre syndrome, which is known to be a phenotypical variant of hereditary nonpolyposis colorectal cancer. Both hereditary nonpolyposis colorectal cancer and Muir–Torre syndrome are caused by inherited DNA mismatch repair defects. As a prominent molecular genetic feature, all tumors associated with a DNA mismatch repair defect exhibit high microsatellite instability. So far, the frequency of DNA mismatch repair defects in patients selected solely on the basis of a sebaceous gland tumor has never been determined. In order to estimate this frequency, we assessed microsatellite instability with up to 10 microsatellite markers in a newly collected unselected series of 25 sebaceous gland neoplasias (six sebaceous adenomas, 16 sebaceous epitheliomas, three sebaceous carcinomas) in comparison to 32 sebaceous gland hyperplasias from unrelated patients. As many as 15 of the 25 sebaceous gland neoplasias (60%), but only one of the 32 sebaceous gland hyperplasias (3%), exhibited high microsatellite instability. Thus, in our study, the majority of patients with a sebaceous gland neoplasia in contrast to patients with a sebaceous gland hyperplasia are highly suspicious for an inherited DNA mismatch repair defect. On the basis of the subsequently collected tumor histories, nine of the 15 patients with a high microsatellite unstable sebaceous gland neoplasia were identified to have Muir–Torre syndrome. In none of these cases, however, were the clinical Amsterdam criteria for diagnosing hereditary nonpolyposis colorectal cancer fulfilled. In the sebaceous tumors of the remaining six patients, high microsatellite instability was an incidental finding. In two of these six patients, single relatives were known to be affected with internal cancer; however, their family histories were not suggestive of Muir–Torre syndrome or hereditary nonpolyposis colorectal cancer. In comparison with microsatellite instability screening studies in a variety of other randomly selected tumors, our study identifies sebaceous gland neoplasias as tumors with the highest frequency of high microsatellite instability reported so far, whereas sebaceous gland hyperplasia rarely exhibits high microsatellite instability. Therefore, screening for microsatellite instability in sebaceous gland neoplasias will be of great value in the detection of an inherited DNA mismatch repair defect, which predisposes to various types of internal cancers

    PRENYLATED CURCUMIN ANALOGUES AS MULTIPOTENT TOOLS TO TACKLE ALZHEIMER'S DISEASE

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    Alzheimer's disease is likely to be caused by copathogenic factors including aggregation of A\u3b2 peptides into oligomers and fibrils, neuroinflammation and oxidative stress. To date, no effective treatments are available and because of the multifactorial nature of the disease, it emerges the need to act on different and simultaneous fronts. Despite the multiple biological activities ascribed to curcumin as neuroprotector, its poor bioavailability and toxicity limit the success in clinical outcomes. To tackle Alzheimer's disease on these aspects, the curcumin template was suitably modified and a small set of analogues was attained. In particular, derivative 1 turned out to be less toxic than curcumin. As evidenced by capillary electrophoresis and transmission electron microscopy studies, 1 proved to inhibit the formation of large toxic A\u3b2 oligomers, by shifting the equilibrium towards smaller non-toxic assemblies and to limit the formation of insoluble fibrils. These findings were supported by molecular docking and steered molecular dynamics simulations which confirmed the superior capacity of 1 to bind A\u3b2 structures of different complexity. Remarkably, 1 also showed in vitro anti-inflammatory and anti-oxidant properties. In summary, the curcumin-based analogue 1 emerged as multipotent compound worth to be further investigated and exploited in the Alzheimer's disease multi-target context

    Expression of VSX1 in human corneal keratocytes during differentiation into myofibroblasts in response to wound healing

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    PURPOSE. To characterize the expression of the visual system homeobox gene (VSX1) in human corneal keratocytes both in vitro and in vivo. METHODS. The expression of VSX1 was evaluated through semiquantitative RT-PCR, immunofluorescence and in situ hybridization both in corneas (either freshly obtained or wounded) and in collagenase/hyaluronidase-isolated keratocytes grown in the absence or presence of serum to promote keratocyteto-myofibroblast differentiation. RESULTS. Quiescent or resting keratocytes normally residing in the corneal stroma or cultured in vitro in the absence of serum did not express VSX1. In wounded corneas or when cultured in the presence of serum to mimic wound-healing responses, keratocytes underwent fibroblastic transformation (with appearance of ␣-SMA and disappearance of CD-34 and keratocan signals) and started expressing VSX1. CONCLUSIONS. The results show that VSX1 is expressed in vitro and in vivo during human corneal wound healing, a process in which differentiation of corneal keratocytes into myofibroblasts occurs. These data may help to elucidate the role of VSX1 in cornea physiology suggesting a potential involvement in cornea-related diseases such as keratoconus. (Invest Ophthalmol Vis Sci. 2006;47:5243-5250

    High Specificity of Quantitative Methylation-Specific PCR Analysis for MGMT Promoter Hypermethylation Detection in Gliomas

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    Normal brain tissue from 28 individuals and 50 glioma samples were analyzed by real-time Quantitative Methylation-Specific PCR (QMSP). Data from this analysis were compared with results obtained on the same samples by MSP. QMSP analysis demonstrated a statistically significant difference in both methylation level (P = .000009 Mann Whitney Test) and frequencies (P = .0000007, Z-test) in tumour samples as compared with normal brain tissues. Although QMSP and MSP showed similar sensitivity, the specificity of QMSP analysis was significantly higher (93%; CI95%: 84%–100%) as compared with MSP (64%; 95%CI: 46%–82%). Our results suggest that QMSP analysis may represent a powerful tool to identify glioma patients that will benefit from alkylating agents chemotherapy

    Consolidative thoracic radiation therapy for extensive-stage small cell lung cancer in the era of first-line chemoimmunotherapy: preclinical data and a retrospective study in Southern Italy

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    BackgroundConsolidative thoracic radiotherapy (TRT) has been commonly used in the management of extensive-stage small cell lung cancer (ES-SCLC). Nevertheless, phase III trials exploring first-line chemoimmunotherapy have excluded this treatment approach. However, there is a strong biological rationale to support the use of radiotherapy (RT) as a boost to sustain anti-tumor immune responses. Currently, the benefit of TRT after chemoimmunotherapy remains unclear. The present report describes the real-world experiences of 120 patients with ES-SCLC treated with different chemoimmunotherapy combinations. Preclinical data supporting the hypothesis of anti-tumor immune responses induced by RT are also presented.MethodsA total of 120 ES-SCLC patients treated with chemoimmunotherapy since 2019 in the South of Italy were retrospectively analyzed. None of the patients included in the analysis experienced disease progression after undergoing first-line chemoimmunotherapy. Of these, 59 patients underwent TRT after a multidisciplinary decision by the treatment team. Patient characteristics, chemoimmunotherapy schedule, and timing of TRT onset were assessed. Safety served as the primary endpoint, while efficacy measured in terms of overall survival (OS) and progression-free survival (PFS) was used as the secondary endpoint. Immune pathway activation induced by RT in SCLC cells was explored to investigate the biological rationale for combining RT and immunotherapy.ResultsPreclinical data supported the activation of innate immune pathways, including the STimulator of INterferon pathway (STING), gamma-interferon-inducible protein (IFI-16), and mitochondrial antiviral-signaling protein (MAVS) related to DNA and RNA release. Clinical data showed that TRT was associated with a good safety profile. Of the 59 patients treated with TRT, only 10% experienced radiation toxicity, while no ≥ G3 radiation-induced adverse events occurred. The median time for TRT onset after cycles of chemoimmunotherapy was 62 days. Total radiation dose and fraction dose of TRT include from 30 Gy in 10 fractions, up to definitive dose in selected patients. Consolidative TRT was associated with a significantly longer PFS than systemic therapy alone (one-year PFS of 61% vs. 31%, p<0.001), with a trend toward improved OS (one-year OS of 80% vs. 61%, p=0.027).ConclusionMulti-center data from establishments in the South of Italy provide a general confidence in using TRT as a consolidative strategy after chemoimmunotherapy. Considering the limits of a restrospective analysis, these preliminary results support the feasibility of the approach and encourage a prospective evaluation

    A Theatre Attendance Model

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    In this manuscript, the author proposes a model that constitutes a generalization of the El Farol Bar problem. In this model, in each period, each one of the n agents decides the arrival time at a theatre with free entry in which there are k (k<n) seats. Each individual wants to minimize the waiting time (before the beginning of the show) but prefers to assist to the show comfortably seated. The author introduces a utility function that takes into account these aspects, in which also agents’ heterogeneity, in terms of different patience or comfort preferences, is considered. The author examines some possible approaches to this problem, and provides a new inductive reasoning modeling for a simplified version of this Theatre Attendance model, according to which each agent decides the arrival time at the theatre in a certain period by looking at the outcome of the previous round
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