13 research outputs found

    Modulated linear dynamics of nanobeams accounting for higher gradient effects

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    We present some numerical results for the linear dynamics of nanobeams modulated by an axial force, basing on a recent proposal of literature that encompasses both the standard nonlocal elasticity, according to Eringen, and second-order strain elasticity. Three different possibilities for the elastic potential energy provide different responses that highlight the contributions of nonlocality and strain gradient, plus their combination. An axial force affects the linear stationary dynamics of such nanobeams, inducing suitable variation of the natural angular frequencies for benchmark cases, until static buckling occurs when the natural angular frequency vanishes. Effects of the various elastic potentials on this modulation are investigated and thoroughly commented

    Linear dynamic response of nanobeams accounting for higher gradient effects

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    Linear dynamic response of simply supported nanobeams subjected to a variable axial force is assessed by Galerkin numerical approach. Constitutive behavior is described by three functional forms of elastic energy densities enclosing nonlocal and strain gradient effects and their combination. Linear stationary dynamics of nanobeams is modulated by an axial force which controls the global stiffness of nanostrucure and hence its angular frequencies. Influence of the considered elastic energy densities on dynamical response is investigated and thoroughly commented

    High mobility group A1 protein modulates autophagy in cancer cells.

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    High Mobility Group A1 (HMGA1) is an architectural chromatin protein whose overexpression is a feature of malignant neoplasias with a causal role in cancer initiation and progression. HMGA1 promotes tumor growth by several mechanisms, including increase of cell proliferation and survival, impairment of DNA repair and induction of chromosome instability. Autophagy is a self-degradative process that, by providing energy sources and removing damaged organelles and misfolded proteins, allows cell survival under stress conditions. On the other hand, hyper-activated autophagy can lead to non-apoptotic programmed cell death. Autophagy deregulation is a common feature of cancer cells in which has a complex role, showing either an oncogenic or tumor suppressor activity, depending on cellular context and tumor stage. Here, we report that depletion of HMGA1 perturbs autophagy by different mechanisms. HMGA1-knockdown increases autophagosome formation by constraining the activity of the mTOR pathway, a major regulator of autophagy, and transcriptionally upregulating the autophagy-initiating kinase Unc-51-like kinase 1 (ULK1). Consistently, functional experiments demonstrate that HMGA1 binds ULK1 promoter region and negatively regulates its transcription. On the other hand, the increase in autophagosomes is not associated to a proportionate increase in their maturation. Overall, the effects of HMGA1 depletion on autophagy are associated to a decrease in cell proliferation and ultimately impact on cancer cells viability. Importantly, silencing of ULK1 prevents the effects of HMGA1-knockdown on cellular proliferation, viability and autophagic activity, highlighting how these effects are, at least in part, mediated by ULK1. Interestingly, this phenomenon is not restricted to skin cancer cells, as similar results have been observed also in HeLa cells silenced for HMGA1. Taken together, these results clearly indicate HMGA1 as a key regulator of the autophagic pathway in cancer cells, thus suggesting a novel mechanism through which HMGA1 can contribute to cancer progression

    Multimorbidity and polypharmacy in the elderly: Lessons from REPOSI

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    The dramatic demographic changes that are occurring in the third millennium are modifying the mission of generalist professionals such as primary care physicians and internists. Multiple chronic diseases and the related prescription of multiple medications are becoming typical problems and present many challenges. Unfortunately, the available evidence regarding the efficacy of medications has been generated by clinical trials involving patients completely different from those currently admitted to internal medicine: much younger, affected by a single disease and managed in a highly controlled research environment. Because only registries can provide information on drug effectiveness in real-life conditions, REPOSI started in 2008 with the goal of acquiring data on elderly people acutely admitted to medical or geriatric hospital wards in Italy. The main goals of the registry were to evaluate drug prescription appropriateness, the relationship between multimorbidity/polypharmacy and such cogent outcomes as hospital mortality and re-hospitalization, and the identification of disease clusters that most often concomitantly occur in the elderly. The findings of 3-yearly REPOSI runs (2008, 2010, 2012) suggest the following pertinent tasks for the internist in order to optimally handle their elderly patients: the management of multiple medications, the need to become acquainted with geriatric multidimensional tools, the promotion and implementation of a multidisciplinary team approach to patient health and care and the corresponding involvement of patients and their relatives and caregivers. There is also a need for more research, tailored to the peculiar features of the multimorbid elderly patient

    Adherence to antibiotic treatment guidelines and outcomes in the hospitalized elderly with different types of pneumonia

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    Background: Few studies evaluated the clinical outcomes of Community Acquired Pneumonia (CAP), Hospital-Acquired Pneumonia (HAP) and Health Care-Associated Pneumonia (HCAP) in relation to the adherence of antibiotic treatment to the guidelines of the Infectious Diseases Society of America (IDSA) and the American Thoracic Society (ATS) in hospitalized elderly people (65 years or older). Methods: Data were obtained from REPOSI, a prospective registry held in 87 Italian internal medicine and geriatric wards. Patients with a diagnosis of pneumonia (ICD-9 480-487) or prescribed with an antibiotic for pneumonia as indication were selected. The empirical antibiotic regimen was defined to be adherent to guidelines if concordant with the treatment regimens recommended by IDSA/ATS for CAP, HAP, and HCAP. Outcomes were assessed by logistic regression models. Results: A diagnosis of pneumonia was made in 317 patients. Only 38.8% of them received an empirical antibiotic regimen that was adherent to guidelines. However, no significant association was found between adherence to guidelines and outcomes. Having HAP, older age, and higher CIRS severity index were the main factors associated with in-hospital mortality. Conclusions: The adherence to antibiotic treatment guidelines was poor, particularly for HAP and HCAP, suggesting the need for more adherence to the optimal management of antibiotics in the elderly with pneumonia

    Therapeutic Duplicates in a Cohort of Hospitalized Elderly Patients: Results from the REPOSI Study.

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    BACKGROUND: Explicit criteria for potentially inappropriate prescriptions in the elderly are recommended to avoid prescriptions of duplicate drug classes and to optimize monotherapy within a single drug class before a new agent is considered. Duplicate drug class prescription (or therapeutic duplicates) puts the patient at increased risk of adverse drug reactions with no additional therapeutic benefits. To our knowledge, the prevalence of elderly inpatients receiving therapeutic duplicates has never been studied. OBJECTIVES: Our objective was to assess the prevalence of therapeutic duplicates at admission, discharge, and 3-month follow-up of hospitalized elderly patients. METHODS: This cross-sectional prospective study was conducted in 97 Italian internal medicine and geriatric wards. Therapeutic duplicates were defined as at least two drugs of the same therapeutic class prescribed simultaneously to a patient. A patient's drug therapy at admission relates to prescriptions from general practitioners, whereas prescriptions at discharge are those from hospital internists or geriatricians. RESULTS: The study sample comprised 5821 admitted and 4983 discharged patients. In all, 143 therapeutic duplicates were found at admission and 170 at discharge. The prevalence of patients exposed to at least one therapeutic duplicate rose significantly from hospital admission (2.5 %) to discharge (3.4 %; p = 0.0032). Psychotropic drugs and drugs for peptic ulcer or gastroesophageal reflux disease were the most frequently involved. A total of 86.8 % of patients discharged with at least one therapeutic duplicate were still receiving them at 3-month follow-up. CONCLUSIONS: Hospitalization and drugs prescribed by internists and geriatricians are both factors associated with a small but definite increase in overall therapeutic duplicates in elderly patients admitted to internal medicine and geriatric wards. More attention should be paid to the indications for each drug prescribed, because therapeutic duplicates are not supported by evidence and increase both the risk of adverse drug reactions and costs. Identification of unnecessary therapeutic duplicates is essential for the optimization of polypharmacy

    Gender-differences in disease distribution and outcome in hospitalized elderly: Data from the REPOSI study

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    Background and purpose Women live longer and outnumber men. On the other hand, older women develop more chronic diseases and conditions such as arthritis, osteoporosis and depression, leading to a greater number of years of living with disabilities. The aim of this study was to describe whether or not there are gender differences in the demographic profile, disease distribution and outcome in a population of hospitalized elderly people. Methods Retrospective observational study including all patients recruited for the REPOSI study in the year 2010. Analyses are referred to the whole group and gender categorization was applied. Results A total of 1380 hospitalized elderly subjects, 50.5% women and 49.5% men, were considered. Women were older than men, more often widow and living alone or in nursing homes. Disease distribution showed that malignancy, diabetes, coronary artery disease, chronic kidney disease and chronic obstructive pulmonary disease were more frequent in men, but hypertension, osteoarthritis, anemia and depression were more frequent in women. Severity and comorbidity indexes according to the Cumulative Illness Rating Scale (CIRS-s and CIRS-c) were higher in men, while cognitive impairment evaluated by the Short Blessed Test (SBT), mood disorders by the Geriatric Depression Scale (GDS) and disability in daily life measured by Barthel Index (BI) were worse in women. In-hospital and 3-month mortality rates were higher in men. Conclusions Our study showed a gender dimorphism in the demographic and morbidity profiles of hospitalized elderly people, emphasizing once more the need for a personalized process of healthcare

    Brain and kidney, victims of atrial microembolism in elderly hospitalized patients? Data from the REPOSI study.

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    Background: It is well known that atrial fibrillation (AF) and chronic kidney disease (CKD) are associated with a higher risk of stroke, and new evidence links AF to cognitive impairment, independently from an overt stroke (CI). Our aim was to investigate, assuming an underlying role of atrial microembolism, the impact of CI and CKD in elderly hospitalized patients with AF. Methods: We retrospectively analyzed the data collected on elderly patients in 66 Italian hospitals, in the frame of the REPOSI project. We analyzed the clinical characteristics of patients with AF and different degrees of CI. Multivariate logistic analysis was used to explore the relationship between variables and mortality. Results: Among the 1384 patients enrolled, 321 had AF. Patients with AF were older, had worse CI and disability and higher rates of stroke, hypertension, heart failure, and CKD, and less than 50% were on anticoagulant therapy. Among patients with AF, those with worse CI and those with lower estimated glomerular filtration rate (eGFR) had a higher mortality risk (odds ratio 1.13, p=0.006). Higher disability levels, older age, higher systolic blood pressure, and higher eGFR were related to lower probability of oral anticoagulant prescription. Lower mortality rates were found in patients on oral anticoagulant therapy. Conclusions: Elderly hospitalized patients with AF are more likely affected by CI and CKD, two conditions that expose them to a higher mortality risk. Oral anticoagulant therapy, still underused and not optimally enforced, may afford protection from thromboembolic episodes that probably concur to the high mortality

    Antipsychotic prescription and mortality in hospitalized older persons

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    Background: Recent scientific reports have shown that older persons treated with antipsychotics for dementia-related behavioural symptoms have increased mortality. However, the impact of these drugs prescribed during hospitalization has rarely been assessed. We aimed to investigate whether antipsychotics are associated with an increased risk of mortality during hospitalization and at 3-month follow-up in elderly inpatients. Methods: We analyzed data gathered during two waves (2010 and 2012) by the REPOSI (Registro Politerapie Società Italiana Medicina Interna). All new prescriptions of antipsychotic drugs during hospitalization, whether maintained or discontinued at discharge, were collected, and logistic regression models were used to analyze their association with in-hospital and 3-month mortality. Covariates were age, sex, the Short Blessed Test (SBT) score, and the Cumulative Illness Rating Scale. Results: Among 2703 patients included in the study, 135 (5%) received new prescriptions for antipsychotic drugs. The most frequently prescribed antipsychotic during hospitalization and eventually maintained at discharge was haloperidol (38% and 36% of cases, respectively). Patients newly prescribed with antipsychotics were older and had a higher Cumulative Illness Rating Scale comorbidity index both at admission and at discharge compared to those who did not receive a prescription. Of those prescribed antipsychotics, 71% had an SBT score ≥10 (indicative of dementia), 12% had an SBT score of 5–9 (indicative of questionable dementia); and 17% had an SBT score <5 (indicative of normal cognition). In-hospital mortality was slightly higher in patients prescribed antipsychotic drugs (14.3% vs 9.4%; P = 0.109), but in multivariate analysis only male sex, older age, and higher SBT scores were significantly related to mortality during hospitalization. At 3-month follow-up, only male sex, older age, and higher SBT scores were associated with mortality. Conclusion: We found that the prescription of antipsychotic drugs during hospitalization was not associated with in-hospital or follow-up mortality. Short-term antipsychotic prescriptions (for acutely ill patients) may have a different effect than long-term, repeated prescriptions
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