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Mascia D.,Catholic University of the Sacred Heart | Angeli F.,Maastricht University | Di Vincenzo F.,nnunzio University
Social Science and Medicine

Previous studies have shown that referral networks encompass important mechanisms of coordination and integration among hospitals, which enhance numerous organizational-level benefits, such as productivity, efficiency, and quality of care. The present study advances previous research by demonstrating how hospital referral networks influence patient readmissions. Data include 360,697 hospitalization events within a regional community of hospitals in the Italian National Health Service. Multilevel hierarchical regression analysis tests the impacts of referral networks' structural characteristics on patient hospital readmissions. The results demonstrate that organizational centrality in the overall referral network and ego-network density have opposing effects on the likelihood of readmission events within hospitals; greater centrality is negatively associated with readmissions, whereas greater ego-network density increases the likelihood of readmission events. Our findings support the (re)organization of healthcare systems and provide important indications for policymakers and practitioners. © 2015. Source

In spatial discrete choice models the spatial dependent structure adds complexity in the estimation of parameters. Appropriate general method of moments (GMM) estimation needs inverses of n-by-n matrices and an optimization complexity of the moment conditions for moderate to large samples makes practical applications more difficult. Recently, Klier and McMillen (2008) have proposed a linearized version of the GMM estimator that avoids the infeasible problem of inverting n-by-n matrices when employing large samples. They show that standard GMM reduces to a nonlinear two-stage least squares problem. On the other hand, when we deal with full maximum likelihood (FML) estimation, a multidimensional integration problem arises and a viable computational solution needs to be found. Although it remains somewhat computationally burdensome, since the inverses of matrices dimensioned by the number of observations have to be computed, the ML estimator yields the potential advantage of efficiency. Therefore, through Monte Carlo experiments we compare GMM-based approaches with ML estimation in terms of their computation times and statistical properties. Furthermore, a comparison in terms of the marginal effects also is included. Finally, we recommend an algorithm based on sparse matrices that enables more efficient use of both ML and GMM estimators. © Southern Regional Science Association 2014. Source

Di Nisio C.,University of Chieti Pescara | Sancilio S.,University of Chieti Pescara | Di Giacomo V.,University of Chieti Pescara | Rapino M.,CNR Institute of Neuroscience | And 6 more authors.
International Journal of Oncology

The aim of the present study was to investigate the role of Cyclic-nucleotide Response Element-Binding (CREB) family members and related nuclear transcription factors in the radiation response of human B lymphoma cell lines (Daudi and Ramos). Unlike the more radiosensitive Daudi cells, Ramos cells demonstrated only a moderate increase in early apoptosis after 3-5 Gy irradiation doses, which was detected with Annexin V/PI staining. Moreover, a significant and dose-dependent G2/M phase accumulation was observed in the same cell line at 24 h after both ionizing radiation (IR) doses. Western blot analysis showed an early increase in CREB protein expression that was still present at 3 h and more evident after 3 Gy IR in Ramos cells, along with the dose-dependent upregulation of p53 and NF-B. These findings were consistent with real-time RT-PCR analysis that showed an early-and dose-dependent upregulation of NFKB1, IKBKB and XIAP gene expression. Unexpectedly, pre-treatment with SN50 did not increase cell death, but cell viability. Taken together, these findings let us hypothesise that the early induction and activation of NF-B1 in Ramos cells could mediate necrotic cell death and be linked to other molecules belonging to CREB family and involved in the cell cycle regulation. Source

Ausili Cefaro G.,University of Chieti Pescara | Genovesi D.,University of Chieti Pescara | Vinciguerra A.,University of Chieti Pescara | Trignani M.,University of Chieti Pescara | And 5 more authors.
Strahlentherapie und Onkologie

Background and Purpose: To evaluate the influence of serum hemoglobin level prior to radiotherapy and other prognostic factors on survival in patients with high-grade gliomas. Material and Methods: From 2001-2010, we retrospectively evaluated a total of 48 patients with malignant glioma treated with surgery and postoperative radiochemotherapy with temozolomide. A total of 37 of 48 patients received sequential temozolomide. Hemoglobin levels were assayed before radiotherapy in all patients. The Kaplan-Meier method was applied to estimate the overall survival, while the log-rank test was applied to evaluate the differences on survival probability between prognostic subgroups. Results: Results were assessed in 43 patients. The median overall survival time was 18 months (95% confidence interval: 12-40 months). The 1- and 2-year survival rates were 62.2% and 36.3%, respectively. The prognostic factors analyzed were gender, age, extent of surgery, performance status before and after radiotherapy, sequential chemotherapy, hemoglobin level, and methylation of the O-6-methylguanine-DNA methyltransferase gene (MGMT). In univariate analysis, the variables significantly related to survival were performance status before and after radiotherapy, sequential chemotherapy, and hemoglobin level. The median overall survival in patients with a hemoglobin level ≤ 12 g/dl was 12 months and 23 months in patients with a hemoglobin level > 12 g/dl. The 1- and 2-year survival rates were 46.7% and 20.0%, respectively, for patients with a hemoglobin level ≤ 12 mg/dl and 69.6% and 45.7%, respectively, for patients with a hemoglobin level > 12 g/dl. Conclusion: Our results confirm the impact of well-known prognostic factors on survival. In this research, it was found that a low hemoglobin level before radiotherapy can adversely influence the prognosis of patients with malignant gliomas. © 2011 Urban & Vogel. Source

Salemi S.,University of Rome La Sapienza | Biondo M.I.,University of Rome La Sapienza | Fiorentino C.,University of Rome La Sapienza | Argento G.,University of Rome La Sapienza | And 6 more authors.
Medicine (United States)

Rheumatoid arthritis (RA) is an immune-mediated polyarthritis; currently no pathogenic agent has been identified as a disease trigger. A patient with RA, presumably caused by periodontal infection, whose remission has been observed after periodontitis treatment in absence of specific RA therapy, is reported here for the first time, to our knowledge. A 61-year-old male patient presented migrant arthritis associated with antibodies against citrullinated protein antigens positivity. The clinical features allowed to make RA diagnosis according to the 2010 European League against Rheumatism/American College of Rheumatology RA classification criteria. X-ray of the second upper molar showed chronic apical periodontitis. After its treatment, arthritis remission has been observed in the absence of specific RA therapy. It has been suggested that periodontitis may have a trigger role in RA pathogenesis. This could be explained by the enzymatic action of Porphyromonas gingivalis, probably leading to break tolerance to collagen. The identification and subsequent treatment of periodontitis should therefore be considered pivotal in RA prophylaxis and management. Copyright © 2014 Wolters Kluwer Health / Lippincott Williams & Wilkins. Source

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