70 research outputs found
Eigenfunctions of the Laplacian and associated Ruelle operator
Let be a co-compact Fuchsian group of isometries on the Poincar\'e
disk \DD and the corresponding hyperbolic Laplace operator. Any
smooth eigenfunction of , equivariant by with real
eigenvalue , where , admits an integral
representation by a distribution \dd_{f,s} (the Helgason distribution) which
is equivariant by and supported at infinity \partial\DD=\SS^1. The
geodesic flow on the compact surface \DD/\Gamma is conjugate to a suspension
over a natural extension of a piecewise analytic map T:\SS^1\to\SS^1, the
so-called Bowen-Series transformation. Let be the complex Ruelle
transfer operator associated to the jacobian . M. Pollicott showed
that \dd_{f,s} is an eigenfunction of the dual operator for the
eigenvalue 1. Here we show the existence of a (nonzero) piecewise real analytic
eigenfunction of for the eigenvalue 1, given by an
integral formula \psi_{f,s} (\xi)=\int \frac{J(\xi,\eta)}{|\xi-\eta|^{2s}}
\dd_{f,s} (d\eta), \noindent where is a -valued
piecewise constant function whose definition depends upon the geometry of the
Dirichlet fundamental domain representing the surface \DD/\Gamma
The first 110,593 COVID-19 patients hospitalised in Lombardy: a regionwide analysis of case characteristics, risk factors and clinical outcomes
Objectives: To describe the monthly distribution of COVID-19 hospitalisations, deaths and case-fatality rates (CFR) in Lombardy (Italy) throughout 2020.
Methods: We analysed de-identified hospitalisation data comprising all COVID-19-related admissions from 1 February 2020 to 31 December 2020. The overall survival (OS) from time of first hospitalisation was estimated using the Kaplan-Meier method. We estimated monthly CFRs and performed Cox regression models to measure the effects of potential predictors on OS.
Results: Hospitalisation and death peaks occurred in March and November 2020. Patients aged â„70 years had an up to 180 times higher risk of dying compared to younger patients [70â80: HR 58.10 (39.14â86.22); 80â90: 106.68 (71.01â160.27); â„90: 180.96 (118.80â275.64)]. Risk of death was higher in patients with one or more comorbidities [1: HR 1.27 (95% CI 1.20â1.35); 2: 1.44 (1.33â1.55); â„3: 1.73 (1.58â1.90)] and in those with specific conditions (hypertension, diabetes).
Conclusion: Our data sheds light on the Italian pandemic scenario, uncovering mechanisms and gaps at regional health system level and, on a larger scale, adding to the body of knowledge needed to inform effective health service planning, delivery, and preparedness in times of crisis
A novel integrated platform for the identification of surgical margins in oral squamous cell carcinoma: results from a prospective single-institution series
BackgroundThe optimal surgical margins assessment is capital in oral squamous cell carcinoma (OSCC) management. We evaluated the clinical benefits of integrating intraoperative macroscopic margin (MM) assessment and narrow band imaging (NBI).MethodsSixteen OSCC patients eligible for surgery were prospectively enrolled. For each patient, 2 to 6 bioptic samples of MM and NBI margins were obtained and histologically analyzed for the presence of dysplasia and lymphocytes. Microvessel density was investigated by CD34 immunohistochemistry.ResultsTaken together, 104 specimens were analyzed, including 15% tumors, 33% MM, 33% NBI margins, and 19% MM-NBI overlapping margins. The NBI margins were closer to the lesion in 50% cases, while the same number of MM were more conservative than NBI, irrespective of the tumor site. The rate of histologically positive margins was similar among the two methods, akin to the microvessel density.ConclusionsMM assessment should be integrated but not replaced with the NBI technology to allow for more conservative surgery
Risk factors for pancreas and lung neuroendocrine neoplasms: a case-control study.
Neuroendocrine neoplasia (NEN) has been displaying an incremental trend along the last two decades. This phenomenon is poorly understood, and little information is available on risk factor for neuroendocrine neoplasia development. Aim of this work is to elucidate the role of potentially modifiable risk factors for pancreatic and pulmonary NEN.
We conducted a case-control study on 184 patients with NEN (100 pancreas and 84 lung) and 248 controls. The structured questionnaire included 84 queries on socio-demographic, behavioral, dietary and clinical information.
Increased risk was associated with history of cancer ("other tumor", lung OR = 7.18; 95% CI: 2.55-20.20 and pancreas OR = 5.88; 95% CI: 2.43-14.22; "family history of tumor", lung OR = 2.66; 95% CI: 1.53-4.64 and pancreas OR = 1.94; 95% CI: 1.19-3.17; "family history of lung tumor", lung OR = 2.56; 95% CI: 1.05-6.24 and pancreas OR = 2.60; 95% CI: 1.13-5.95). Type 2 diabetes mellitus associated with an increased risk of pancreatic NEN (OR = 3.01; 95% CI: 1.15-7.89).
Besides site-specific risk factors, there is a significant link between neuroendocrine neoplasia and cancer in general, pointing to a shared cancer predisposition
Geographical distribution of fertility rates in 70 low-income, lower-middle-income, and upper-middle-income countries, 2010â16: a subnational analysis of cross-sectional surveys
Background
Understanding subnational variation in age-specific fertility rates (ASFRs) and total fertility rates (TFRs), and geographical clustering of high fertility and its determinants in low-income and middle-income countries, is increasingly needed for geographical targeting and prioritising of policy. We aimed to identify variation in fertility rates, to describe patterns of key selected fertility determinants in areas of high fertility.
Methods
We did a subnational analysis of ASFRs and TFRs from the most recent publicly available and nationally representative cross-sectional Demographic and Health Surveys and Multiple Indicator Cluster Surveys collected between 2010 and 2016 for 70 low-income, lower-middle-income, and upper-middle-income countries, across 932 administrative units. We assessed the degree of global spatial autocorrelation by using Moran's I statistic and did a spatial cluster analysis using the Getis-Ord Gi* local statistic to examine the geographical clustering of fertility and key selected fertility determinants. Descriptive analysis was used to investigate the distribution of ASFRs and of selected determinants in each cluster.
Findings
TFR varied from below replacement (2·1 children per women) in 36 of the 932 subnational regions (mainly located in India, Myanmar, Colombia, and Armenia), to rates of 8 and higher in 14 subnational regions, located in sub-Saharan Africa and Afghanistan. Areas with high-fertility clusters were mostly associated with areas of low prevalence of women with secondary or higher education, low use of contraception, and high unmet needs for family planning, although exceptions existed.
Interpretation
Substantial within-country variation in the distribution of fertility rates highlights the need for tailored programmes and strategies in high-fertility cluster areas to increase the use of contraception and access to secondary education, and to reduce unmet need for family planning.
Funding
Wellcome Trust, the UK Foreign, Commonwealth and Development Office, and the Bill & Melinda Gates Foundation
Coffee consumption and gastric cancer: A pooled analysis from the Stomach cancer Pooling Project consortium
open41siThis study was supported by the Associazione Italiana per la Ricerca sul Cancro (AIRC), Project no. 21378 (Investigator Grant), and by the Italian League for the Fight Against Cancer (LILT). The authors thank the European Cancer Prevention (ECP) Organization for providing support for the StoP meetings. The Unidade de Investigação em Epidemiologia â Instituto de SaĂșde PĂșblica da Universidade do Porto (EPIUnit; UIDB/04750/2020) was funded by the Foundation for Science and Technology â FCT (Portuguese Ministry of Science, Technology and Higher Education). SM was also funded by the project âNEON-PC - Neuro-oncological complications of prostate cancer: longitudinal study of cognitive declineâ (POCI-01-0145-FEDER-032358; ref. PTDC/SAU-EPI/32358/2017), which is funded by FEDER through the Operational Programme competitiveness and Internationalization, and national funding from FCT. We also thank all MCC-Spain study collaborators (CIBERESP, ISCIII, ISGlobal, ICO, University of Huelva, University of Oviedo, University of Cantabria, ibs.Granada, Instituto Salud PĂșblica de Navarra, FISABIO, Murcia Regional Health Authority and cols).Objective This study aimed to evaluate and quantify the relationship between coffee and gastric cancer using a uniquely large dataset from an international consortium of observational studies on gastric cancer, including data from 18 studies, for a total of 8198 cases and 21 419 controls. Methods A two-stage approach was used to obtain the pooled odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) for coffee drinkers versus never or rare drinkers. A one-stage logistic mixed-effects model with a random intercept for each study was used to estimate the dose-response relationship. Estimates were adjusted for sex, age and the main recognized risk factors for gastric cancer. Results Compared to never or rare coffee drinkers, the estimated pooled OR for coffee drinkers was 1.03 (95% CI, 0.94-1.13). When the amount of coffee intake was considered, the pooled ORs were 0.91 (95% CI, 0.81-1.03) for drinkers of 1-2 cups per day, 0.95 (95% CI, 0.82-1.10) for 3-4 cups, and 0.95 (95% CI, 0.79-1.15) for five or more cups. An OR of 1.20 (95% CI, 0.91-1.58) was found for heavy coffee drinkers (seven or more cups of caffeinated coffee per day). A positive association emerged for high coffee intake (five or more cups per day) for gastric cardia cancer only. Conclusions These findings better quantify the previously available evidence of the absence of a relevant association between coffee consumption and gastric cancer.openMartimianaki G.; Bertuccio P.; Alicandro G.; Pelucchi C.; Bravi F.; Carioli G.; Bonzi R.; Rabkin C.S.; Liao L.M.; Sinha R.; Johnson K.; Hu J.; Palli D.; Ferraroni M.; Lunet N.; Morais S.; Tsugane S.; Hidaka A.; Hamada G.S.; Lopez-Carrillo L.; Hernandez-Ramirez R.U.; Zaridze D.; Maximovitch D.; Aragones N.; Martin V.; Ward M.H.; Vioque J.; Garcia De La Hera M.; Zhang Z.-F.; Kurtz R.C.; Lagiou P.; Lagiou A.; Trichopoulou A.; Karakatsani A.; Malekzadeh R.; Camargo M.C.; Curado M.P.; Boccia S.; Boffetta P.; Negri E.; La Vecchia C.Martimianaki G.; Bertuccio P.; Alicandro G.; Pelucchi C.; Bravi F.; Carioli G.; Bonzi R.; Rabkin C.S.; Liao L.M.; Sinha R.; Johnson K.; Hu J.; Palli D.; Ferraroni M.; Lunet N.; Morais S.; Tsugane S.; Hidaka A.; Hamada G.S.; Lopez-Carrillo L.; Hernandez-Ramirez R.U.; Zaridze D.; Maximovitch D.; Aragones N.; Martin V.; Ward M.H.; Vioque J.; Garcia De La Hera M.; Zhang Z.-F.; Kurtz R.C.; Lagiou P.; Lagiou A.; Trichopoulou A.; Karakatsani A.; Malekzadeh R.; Camargo M.C.; Curado M.P.; Boccia S.; Boffetta P.; Negri E.; La Vecchia C
Comparison of anticoagulation quality between acenocoumarol and warfarin in patients with mechanical prosthetic heart valves: Insights from the nationwide PLECTRUM study
Vitamin K antagonists are indicated for the thromboprophylaxis in patients with mechanical prosthetic heart valves (MPHV). However, it is unclear whether some differences between acenocoumarol and warfarin in terms of anticoagulation quality do exist. We included 2111 MPHV patients included in the nationwide PLECTRUM registry. We evaluated anticoagulation quality by the time in therapeutic range (TiTR). Factors associated with acenocoumarol use and with low TiTR were investigated by multivariable logistic regression analysis. Mean age was 56.8 ± 12.3 years; 44.6% of patients were women and 395 patients were on acenocoumarol. A multivariable logistic regression analysis showed that patients on acenocoumarol had more comorbidities (i.e., â„3, odds ratio (OR) 1.443, 95% confidence interval (CI) 1.081-1.927, p = 0.013). The mean TiTR was lower in the acenocoumarol than in the warfarin group (56.1 ± 19.2% vs. 61.6 ± 19.4%, p < 0.001). A higher prevalence of TiTR (<60%, <65%, or <70%) was found in acenocoumarol users than in warfarin ones (p < 0.001 for all comparisons). Acenocoumarol use was associated with low TiTR regardless of the cutoff used at multivariable analysis. A lower TiTR on acenocoumarol was found in all subgroups of patients analyzed according to sex, hypertension, diabetes, age, valve site, atrial fibrillation, and INR range. In conclusion, anticoagulation quality was consistently lower in MPHV patients on acenocoumarol compared to those on warfarin
The Neutrophil-Lymphocyte Ratio is an Independent Prognostic Factor for Overall Survival in Hispanic Patients with Gastric Adenocarcinoma
Introduction
High values of neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are related with poor prognosis in patients with gastric cancer. However, this association has been rarely assessed in Hispanic populations that show important clinicopathological differences to Asian and Caucasian patients. In this study, we determined the prognostic value of these biomarkers in Hispanic patients from Costa Rica.
Materials and Methods
We retrieved data regarding pre-treatment NLR and PLR, as well as clinical variables from medical records of 381 consecutive gastric cancer patients treated in four major hospitals in Costa Rica between 2009 and 2012. Univariate and multiple Cox regression analyses were performed to assess the value of NLR and PLR as predictors of overall survival (OS) and disease-free survival (DFS). The best cutoff point was based on the maximization of the Log-rank test.
Results
Median follow-up was 13.21 months. In univariate analysis, a NLRââ„â5 was associated with reduced DFS (hazard ratio (HR) 2.31; 95% confidence interval (CI) 1.78â3.00; pâ<â0.001) and poor OS (HR 2.24; 95% CI 1.72â2.92; pâ<â0.001). Similarly, a PLRââ„â350 was associated with worse DFS (HR 2.28; 95% CI 1.70â3.06; pâ<â0.001) and poor OS (HR 2.33; 95% CI 1.73â3.13; pâ<â0.001). After adjustment for potential confounders, multivariate analysis revealed that only the NLRââ„â5 was independently associated with worse DFS (HR 1.97; 95% CI 1.44â2.47) and OS (HR 1.59; 95%CI 1.15â2.28).
Conclusions
NLRââ„â5 was independently associated with worse OS and DFS in Hispanic patients with gastric cancer.Universidad de Costa Rica/[817-B2-371]/UCR/Costa RicaUCR::VicerrectorĂa de Docencia::Salud::Facultad de Medicina::Escuela de MedicinaUCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias de la Salud::Instituto de Investigaciones FarmacĂ©uticas (INIFAR)UCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias BĂĄsicas::Centro de InvestigaciĂłn en Estructuras MicroscĂłpicas (CIEMIC
Post-diagnosis serum 25-hydroxyvitamin D concentrations in women treated for breast cancer participating in a lifestyle trial in Italy
Objective. To report cross-sectionally serum levels of 25-hydroxyvitamin D [25(OH)D] in women living in Italy within 12 months from breast cancer (BC) diagnosis.
Methods. Baseline data were obtained from 394 women diagnosed with primary BC, enrolled from 2016 to 2019 in a lifestyle trial conducted in Italy. Subjectsâ characteristics were compared between two 25(OH)D concentrations (hypovitaminosis D<20 and â„20 ng/mL) with the Chi-squared test or Fisherâs exact test for small-expected counts. Using multiple logistic regression-adjusted models, we estimated odds ratios (ORs) of hypovitaminosis D with 95% confidence intervals (CIs) in the total sample and in the unsupplemented subgroup.
Results. Hypovitaminosis D was found in 39% of all subjects, 60% in unsupplemented subjects, and 10% in supplemented subjects. Increasing ORs of hypovitaminosis D were found with increasing body mass index, 25-30, >30, and â„35 versus <25 kg/m2 (ORs: 2.50, 4.64, and 5.81, respectively, in the total cohort and ORs: 2.68, 5.38, and 7.08 in the unsupplemented); living in the most southern Italian region (OR 2.50, 95%CI 1.22-5.13); and with hypertriglyceridemia (OR 2.46; 95%CI 1.16-5.22), chemotherapy history (OR 1.86, 95%CI 1.03-3.38), and inversely with anti-estrogenic therapy (OR 0.43, 95%CI 0.24-0.75) in the total sample.
Conclusions. Hypovitaminosis D in women recently diagnosed with BC and participating in a lifestyle trial in Italy was widespread and highest with obesity, hypertriglyceridemia, and chemotherapy use. Considering that hypovitaminosis D is a risk factor for lower efficacy of bone density treatments and possibly BC mortality, our results suggest the need to promptly address and treat vitamin D deficiency
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