97 research outputs found

    Volatile opinions and optimal control of vaccine awareness campaigns: chaotic behaviour of the Forward-Backward Sweep algorithm vs heuristic direct optimization

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    In modern societies the main sources of information are Internet-based social networks. Thus, the opinion of citizens on key topics, such as vaccines, is very volatile. Here, we explore the impact of volatility on the modelling of public response to vaccine awareness campaigns for favouring vaccine uptake. We apply a quasi-steady-state approximation to the model of spread and control of Susceptible-Infected-Removed diseases proposed in (d’Onofrio et al., PLoS One, 2012). This allows us to infer and analyze a new behavioural epidemiology model that is nonlinear in the control. Then, we investigate the efficient design of vaccine awareness campaigns by adopting optimal control theory. The resulting problem has important issues: (i) the integrand of its objective functional is non-convex; (ii) the application of forward-backward sweep (FBS) and gradient descent algorithms in some key cases does not work; (iii) analytical approaches provide continuous solutions that cannot rigorously be implemented since Public Health interventions cannot be fully flexible. Thus, on the one hand, we resort to direct optimization of the objective functional via heuristic stochastic optimization, in particular via particle swarm optimization and differential evolution algorithms. On the other hand, we investigate the non-convergence of the FBS algorithm with tools of the statistical theory of nonlinear chaotic time-series. Finally, since the direct optimization algorithms are stochastic, we provide a statistical assessment of the obtained solutions

    Optimal Public Health intervention in a behavioural vaccination model: the interplay between seasonality, behaviour and latency period

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    Hesitancy and refusal of vaccines preventing childhood diseases are spreading due to ‘pseudo-rational’ behaviours: parents overweigh real and imaginary side effects of vaccines. Nonetheless, the ‘Public Health System’ (PHS) may enact public campaigns to favour vaccine uptake. To determine the optimal time profiles for such campaigns, we apply the optimal control theory to an extension of the susceptible-infectious-removed (SIR)-based behavioural vaccination model by d’Onofrio et al. (2012, PLoS ONE, 7, e45653). The new model is of susceptible-exposed-infectious-removed (SEIR) type under seasonal fluctuations of the transmission rate. Our objective is to minimize the total costs of the disease: the disease burden, the vaccination costs and a less usual cost: the economic burden to enact the PHS campaigns. We apply the Pontryagin minimum principle and numerically explore the impact of seasonality, human behaviour and latency rate on the control and spread of the target disease. We focus on two noteworthy case studies: the low (resp. intermediate) relative perceived risk of vaccine side effects and relatively low (resp. very low) speed of imitation. One general result is that seasonality may produce a remarkable impact on PHS campaigns aimed at controlling, via an increase of the vaccination uptake, the spread of a target infectious disease. In particular, a higher amplitude of the seasonal variation produces a higher effort and this, in turn, beneficially impacts the induced vaccine uptake since the larger is the strength of seasonality, the longer the vaccine propensity remains large. However, such increased effort is not able to fully compensate the action of seasonality on the prevalence

    Migraine, arousal and sleep deprivation: comment on: "sleep quality, arousal and pain thresholds in migraineurs: a blinded controlled polysomnographic study"

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    We discuss the hypothesis proposed by Engstrom and coworkers that Migraineurs have a relative sleep deprivation, which lowers the pain threshold and predispose to attacks. Previous data indicate that Migraineurs have a reduction of Cyclic Alternating Pattern (CAP), an essential mechanism of NREM sleep regulation which allows to dump the effect of incoming disruptive stimuli, and to protect sleep. The modifications of CAP observed in Migraineurs are similar to those observed in patients with impaired arousal (narcolepsy) and after sleep deprivation. The impairment of this mechanism makes Migraineurs more vulnerable to stimuli triggering attacks during sleep, and represents part of a more general vulnerability to incoming stimuli

    In Vitro Antibacterial and Anti-Inflammatory Activity of Arctostaphylos uva-ursi Leaf Extract against Cutibacterium acnes

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    Cutibacterium acnes (C. acnes) is the main causative agent of acne vulgaris. The study aims to evaluate the antimicrobial activity of a natural product, Arctostaphylos uva-ursi leaf extract, against C. acnes. Preliminary chemical-physical characterization of the extract was carried out by means of FT-IR, TGA and XPS analyses. Skin permeation kinetics of the extract conveyed by a toning lotion was studied in vitro by Franz diffusion cell, monitoring the permeated arbutin (as the target component of the extract) and the total phenols by HPLC and UV-visible spectrophotometry, respectively. Antimicrobial activity and time-killing assays were performed to evaluate the effects of Arctostaphylos uva-ursi leaf extract against planktonic C. acnes. The influence of different Arctostaphylos uva-ursi leaf extract concentrations on the biofilm biomass inhibition and degradation was evaluated by the crystal violet (CV) method. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test was used to determine the viability of immortalized human keratinocytes (HaCaT) after exposure to Arctostaphylos uva-ursi leaf extract for 24 and 48 h. Levels of interleukin (IL)-1 beta, IL-6, IL-8 and tumour necrosis factor (TNF)-alpha were quantified after HaCaT cells cotreatment with Arctostaphylos uva-ursi leaf extract and heat-killed C. acnes. The minimum inhibitory concentration (MIC) which exerted a bacteriostatic action on 90% of planktonic C. acnes (MIC90) was 0.6 mg/mL. Furthermore, MIC and sub-MIC concentrations influenced the biofilm formation phases, recording a percentage of inhibition that exceeded 50 and 40% at 0.6 and 0.3 mg/mL. Arctostaphylos uva-ursi leaf extract disrupted biofilm biomass of 57 and 45% at the same concentrations mentioned above. Active Arctostaphylos uva-ursi leaf extract doses did not affect the viability of HaCaT cells. On the other hand, at 1.25 and 0.6 mg/mL, complete inhibition of the secretion of pro-inflammatory cytokines was recorded. Taken together, these results indicate that Arctostaphylos uva-ursi leaf extract could represent a natural product to counter the virulence of C. acnes, representing a new alternative therapeutic option for the treatment of acne vulgaris

    Multicenter evaluation of use of dried blood spot compared to conventional plasma in measurements of globotriaosylsphingosine (LysoGb3) concentration in 104 Fabry patients.

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    Abstract Objectives Fabry disease (FD) is an X-linked lysosomal storage disorder, resulting from a deficiency of the enzyme α-galactosidase A, responsible for breaking down glycolipids such as globotriaosylceramide and its deacylated derivative, globotriaosylsphingosine (LysoGb3). Here, we compare the levels of LysoGb3 in dried blood spots (DBS) and plasma in patients with classic and late-onset phenotypes. Methods LysoGb3 measurements were performed in 104 FD patients, 39 males and 65 females. Venous blood was collected. A portion was spotted onto filter paper and another portion separated to obtain plasma. The LysoGb3 concentrations in DBS and plasma were determined by highly sensitive electrospray ionization liquid chromatography tandem mass spectrometry. Agreement between different matrices was assessed using linear regression and Bland Altman analysis. Results The method on DBS was validated by evaluating its precision, accuracy, matrix effect, recovery, and stability. The analytical performances were verified by comparison of a total of 104 paired DBS and plasma samples from as many FD patients (representing 46 GLA variants). There was a strong correlation between plasma and the corresponding DBS LysoGb3 concentrations, with few exceptions. Discrepancies were observed in anemic patients with typically low hematocrit levels compared to the normal range. Conclusions The method proved to be efficient for the rapid analysis of LysoGb3. DBS provides a convenient, sensitive, and reproducible method for measuring LysoGb3 levels for diagnosis, initial phenotypic assignment, and therapeutic monitoring in patients with FD

    Safety and efficacy of topiramate in neonates with hypoxic ischemic encephalopathy treated with hypothermia (NeoNATI).

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    Abstract Background Despite progresses in neonatal care, the mortality and the incidence of neuro-motor disability after perinatal asphyxia have failed to show substantial improvements. In countries with a high level of perinatal care, the incidence of asphyxia responsible for moderate or severe encephalopathy is still 2–3 per 1000 term newborns. Recent trials have demonstrated that moderate hypothermia, started within 6 hours after birth and protracted for 72 hours, can significantly improve survival and reduce neurologic impairment in neonates with hypoxic-ischemic encephalopathy. It is not currently known whether neuroprotective drugs can further improve the beneficial effects of hypothermia. Topiramate has been proven to reduce brain injury in animal models of neonatal hypoxic ischemic encephalopathy. However, the association of mild hypothermia and topiramate treatment has never been studied in human newborns. The objective of this research project is to evaluate, through a multicenter randomized controlled trial, whether the efficacy of moderate hypothermia can be increased by concomitant topiramate treatment. Methods/Design Term newborns (gestational age ≥ 36 weeks and birth weight ≥ 1800 g) with precocious metabolic, clinical and electroencephalographic (EEG) signs of hypoxic-ischemic encephalopathy will be randomized, according to their EEG pattern, to receive topiramate added to standard treatment with moderate hypothermia or standard treatment alone. Topiramate will be administered at 10 mg/kg once a day for the first 3 days of life. Topiramate concentrations will be measured on serial dried blood spots. 64 participants will be recruited in the study. To evaluate the safety of topiramate administration, cardiac and respiratory parameters will be continuously monitored. Blood samplings will be performed to check renal, liver and metabolic balance. To evaluate the efficacy of topiramate, the neurologic outcome of enrolled newborns will be evaluated by serial neurologic and neuroradiologic examinations. Visual function will be evaluated by means of behavioural standardized tests. Discussion This pilot study will explore the possible therapeutic role of topiramate in combination with moderate hypothermia. Any favourable results of this research might open new perspectives about the reduction of cerebral damage in asphyxiated newborns. Trial registration Current Controlled Trials ISRCTN62175998; ClinicalTrials.gov Identifier NCT01241019; EudraCT Number 2010-018627-25</p

    Clinical characteristics of a large cohort of patients with narcolepsy candidate for pitolisant: a cross-sectional study from the Italian PASS Wakix® Cohort

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    Introduction: Narcolepsy is a chronic and rare hypersomnia of central origin characterized by excessive daytime sleepiness and a complex array of symptoms as well as by several medical comorbidities. With growing pharmacological options, polytherapy may increase the possibility of a patient-centered management of narcolepsy symptoms. The aims of our study are to describe a large cohort of Italian patients with narcolepsy who were candidates for pitolisant treatment and to compare patients’ subgroups based on current drug prescription (drug-naïve patients in whom pitolisant was the first-choice treatment, switching to pitolisant from other monotherapy treatments, and adding on in polytherapy). Methods: We conducted a cross-sectional survey based on Italian data from the inclusion visits of the Post Authorization Safety Study of pitolisant, a 5-year observational, multicenter, international study. Results: One hundred ninety-one patients were enrolled (76.4% with narcolepsy type 1 and 23.6% with narcolepsy type 2). Most patients (63.4%) presented at least one comorbidity, mainly cardiovascular and psychiatric. Pitolisant was prescribed as an add-on treatment in 120/191 patients (62.8%), as switch from other therapies in 42/191 (22.0%), and as a first-line treatment in 29/191 (15.2%). Drug-naive patients presented more severe sleepiness, lower functional status, and a higher incidence of depressive symptoms. Conclusion: Our study presents the picture of a large cohort of Italian patients with narcolepsy who were prescribed with pitolisant, suggesting that polytherapy is highly frequent to tailor a patient-centered approach

    Prevalence and predictor factors of respiratory impairment in a large cohort of patients with Myotonic Dystrophy type 1 (DM1): A retrospective, cross sectional study

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    Introduction: Respiratory complications are relevant in DM1, leading to a significantly increased morbidity and mortality risk in these patients; however, so far only few studies concerning respiratory function have been conducted in DM1 patients. We report a retrospective, multicenter, cross sectional study on a large cohort of DM1 patients widely characterized in the phenotype, to assess prevalence and identify predictors of restrictive respiratory syndrome. Methods: 268 DM1 subjects aged &gt;18 years, who had recently performed spirometric tests were included; restrictive syndrome was diagnosed if forced vital capacity (FVC) &lt;80% of predicted. This cut-off was used for statistical univariate and multivariate analysis. Results: 51.9% patients showed a restrictive syndrome, and half of them had indication to non-invasive ventilation (NIV), yet only 50% resulted compliant to NIV. CTG expansion size in leukocytes, clinical muscle severity, most functional parameters of respiratory muscle involvement, presence of cardiac conduction disturbances, pacemaker (PMK), exertion dyspnea, obstructive sleep apnea, and indication and compliance to NIV were all significantly associated with restrictive syndrome at the univariate analysis; in the multivariate model only the first two factors resulted independent predictors. Discussion: A high prevalence of restrictive syndrome in our DM1 cohort, mainly due to respiratory muscles weakness, was observed and documented; the severity of muscle impairment and the CTG expansion size confirmed to be independent predictors of respiratory restriction. Our data suggest that optimization of respiratory therapeutic management, particularly regarding launching of NIV, might help to reduce the rate of deaths due to respiratory complications in DM1

    Functional and radiological outcomes after bridging therapy versus direct thrombectomy in stroke patients with unknown onset: Bridging therapy versus direct thrombectomy in unknown onset stroke patients with 10-point ASPECTS

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    BACKGROUND AND PURPOSE: The aim was to assess functional and radiological outcomes after bridging therapy (intravenous thrombolysis plus mechanical thrombectomy) versus direct mechanical thrombectomy (MT) in unknown onset stroke patients. METHODS: A cohort study was conducted on prospectively collected data from unknown onset stroke patients who received endovascular procedures at ≤6 h from symptom recognition or awakening time. RESULTS: Of the 349 patients with a 10-point Alberta Stroke Program Early Computed Tomography Score (ASPECTS), 248 received bridging and 101 received direct MT. Of the 134 patients with 6-9-point ASPECTS, 123 received bridging and 111 received direct MT. Each patient treated with bridging was propensity score matched with a patient treated with direct MT for age, sex, study period, pre-stroke disability, stroke severity, type of stroke onset, symptom recognition to groin time (or awakening to groin time), ASPECTS and procedure time. In the two matched groups with 10-point ASPECTS (n = 73 vs. n = 73), bridging was associated with higher rates of excellent outcome (46.6% vs. 28.8%; odds ratio 2.302, 95% confidence interval 1.010-5.244) and successful recanalization (83.6% vs. 63%; odds ratio 3.028, 95% confidence interval 1.369-6.693) compared with direct MT; no significant association was found between bridging and direct MT with regard to rate of symptomatic intracerebral hemorrhage (0% vs. 1.4%). In the two matched groups with 6-9-point ASPECTS (n = 45 vs. n = 45), no significant associations were found between bridging and direct MT with regard to rates of excellent functional outcome (44.4% vs. 31.1%), successful recanalization (73.3% vs. 76.5%) and symptomatic intracerebral hemorrhage (0% vs. 0%). CONCLUSIONS: Bridging at ≤ 6 h of symptom recognition or awakening time was associated with better functional and radiological outcomes in unknown onset stroke patients with 10-point ASPECTS
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