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Search Results: 1 - 10 of 196460 matches for " Flora E van Leeuwen "
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Incidence of cancer in the area around Amsterdam Airport Schiphol in 1988–2003: a population-based ecological study
Otto Visser, Joop H van Wijnen, Flora E van Leeuwen
BMC Public Health , 2005, DOI: 10.1186/1471-2458-5-127
Abstract: In a population-based study using the regional cancer registry, we estimated the cancer incidence during 1988–2003 in residents of the area surrounding Schiphol. We defined a study area based on aircraft noise contours and 4-digit postal code areas, since historical data on ambient air pollution were not available and recent emission data did not differ from the background urban air quality.In residents of the study area 13 207 cancer cases were diagnosed, which was close to the expected number, using national incidence rates as a reference (standardized incidence ratio [SIR] 1.02). We found a statistically significantly increased incidence of hematological malignancies (SIR 1.12, 95% confidence interval [CI]: 1.05, 1.19), mainly due to high rates for non-Hodgkin lymphoma (SIR 1.22, 95% CI: 1.12, 1.33) and acute lymphoblastic leukemia (SIR 1.34, 95% CI: 0.95, 1.83). The incidence of cancer of the respiratory system was statistically significantly decreased (SIR 0.94, 95% CI: 0.90, 0.99), due to the low rate in males (SIR 0.89). In the core zone of the study area, cancer incidence was slightly higher than in the remaining ring zone (rate ratio of the core zone compared to the ring zone 1.05, 95% CI 1.01, 1.10). This was caused by the higher incidence of cancer of the respiratory system, prostate and the female genital organs in the core zone in comparison to the ring zone.The overall cancer incidence in the Schiphol area was similar to the national incidence. The moderately increased risk of hematological malignancies could not be explained by higher levels of ambient air pollution in the Schiphol area. This observation warrants further research, for example in a study with focus on substances in urban ambient air pollution, as similar findings were observed in Greater Amsterdam.Amsterdam Airport Schiphol is one of the main airports of Europe. The airport is a major source of complaints about aircraft noise, noise related adverse health effects and – especially since
Endometrial cancer survival after breast cancer in relation to tamoxifen treatment: Pooled results from three countries
Michael E Jones, Flora E van Leeuwen, Wilhelmina E Hoogendoorn, Marian JE Mourits, Harry Hollema, Hester van Boven, Michael F Press, Leslie Bernstein, Anthony J Swerdlow
Breast Cancer Research , 2012, DOI: 10.1186/bcr3206
Abstract: We pooled case-patient data from the three largest case-control studies of tamoxifen in relation to endometrial cancer after breast cancer (1,875 patients: Netherlands, 765; United Kingdom, 786; United States, 324) and collected follow-up information on vital status. Breast cancers were diagnosed in 1972 to 2005 with endometrial cancers diagnosed in 1978 to 2006. We used Cox proportional hazards survival analysis to estimate hazard ratios (HRs) and 95% confidence intervals (CI).A total of 1,104 deaths occurred during, on average, 5.8 years following endometrial cancer (32% attributed to breast cancer, 25% to endometrial cancer). Mortality from endometrial cancer increased significantly with unfavorable non-endometrioid morphologies (P < 0.0001), International Federation of Gynaecology and Obstetrics staging system for gynecological malignancy (FIGO) stage (P < 0.0001) and age (P < 0.0001). No overall association was observed between tamoxifen treatment and endometrial cancer mortality (HR = 1.17 (95% CI: (0.89 to 1.55)). Tamoxifen use for at least five years was associated with increased endometrial cancer mortality (HR = 1.59 (1.13 to 2.25)). This association appeared to be due primarily to the excess of unfavorable histologies and advanced stage in women using tamoxifen for five or more years since the association with mortality was no longer significant after adjustment for morphological type and FIGO stage (HR = 1.37 (0.97 to 1.93)). Those patients with endometrioid tumors, who stopped tamoxifen use at least five years before their endometrial cancer diagnosis, had a greater mortality risk from endometrial cancer than endometrioid patients with no tamoxifen exposure (HR = 2.11 (1.13 to 3.94)). The explanation for this latter observation is not apparent.Patients with endometrial cancer after breast cancer who received tamoxifen treatment for five years for breast cancer have greater endometrial cancer mortality risk than those who did not receive tamoxifen. This
Combined effects of single nucleotide polymorphisms TP53 R72P and MDM2 SNP309, and p53 expression on survival of breast cancer patients
Marjanka K Schmidt, Johanna Tommiska, Annegien Broeks, Flora E van Leeuwen, Laura J Van't Veer, Paul DP Pharoah, Douglas F Easton, Mitul Shah, Manjeet Humphreys, Thilo D?rk, Scarlett A Reincke, Rainer Fagerholm, Carl Blomqvist, Heli Nevanlinna
Breast Cancer Research , 2009, DOI: 10.1186/bcr2460
Abstract: We pooled data from four breast cancer cohorts within the Breast Cancer Association Consortium for which both TP53 R72P and MDM2 SNP309 were genotyped and follow-up was available (n = 3,749). Overall and breast cancer-specific survival analyses were performed using Kaplan-Meier analysis and multivariate Cox's proportional hazards regression models.Survival of patients did not differ by carriership of either germ-line variant, R72P (215G>C) or SNP309 (-410G>T) alone. Immunohistochemical p53 staining of the tumor was available for two cohorts (n = 1,109 patients). Survival was worse in patients with p53-positive tumors (n = 301) compared to patients with p53-negative tumors (n = 808); breast cancer-specific survival: HR 1.6 (95% CI 1.2 to 2.1), P = 0.001. Within the patient group with p53-negative tumors, TP53 rare homozygous (CC) carriers had a worse survival than G-allele (GG/GC) carriers; actuarial breast cancer-specific survival 71% versus 80%, P = 0.07; HR 1.8 (1.1 to 3.1), P = 0.03. We also found a differential effect of combinations of the two germ-line variants on overall survival; homozygous carriers of the G-allele in MDM2 had worse survival only within the group of TP53 C-allele carriers; actuarial overall survival (GG versus TT/TG) 64% versus 75%, P = 0.001; HR (GG versus TT) 1.5 (1.1 to 2.0), P = 0.01. We found no evidence for a differential effect of MDM2 SNP309 by p53 protein expression on survival.The TP53 R72P variant may be an independent predictor for survival of patients with p53-negative tumors. The combined effect of TP53 R72P and MDM2 SNP309 on survival is in line with our a priori biologically-supported hypothesis, that is, the role of enhanced DNA repair function of the TP53 Pro-variant, combined with increased expression of the Mdm2 protein, and thus overall attenuation of the p53 pathway in the tumor cells.Breast cancer outcome may be affected by germ-line variants in genes that play a role in DNA damage control and repair such as TP53 (R72P
Identification of women with an increased risk of developing radiation-induced breast cancer: a case only study
Annegien Broeks, Linde M Braaf, Angelina Huseinovic, Anke Nooijen, Jos Urbanus, Frans BL Hogervorst, Marjanka K Schmidt, Jan GM Klijn, Nicola S Russell, Flora E Van Leeuwen, Laura J Van 't Veer
Breast Cancer Research , 2007, DOI: 10.1186/bcr1668
Abstract: We evaluated the contribution of germline mutations in the DDRP genes BRCA1, BRCA2, CHEK2 and ATM to the risk of radiation-induced contralateral breast cancer (CBC). The germline mutation frequency was assessed, in a case-only study, in women who developed a CBC after they had a first breast cancer diagnosed before the age of 50 years, and who were (n = 169) or were not (n = 78) treated with radiotherapy for their first breast tumour.We identified 27 BRCA1, 5 BRCA2, 15 CHEK2 and 4 truncating ATM germline mutation carriers among all CBC patients tested (21%). The mutation frequency was 24.3% among CBC patients with a history of radiotherapy, and 12.8% among patients not irradiated for the first breast tumour (odds ratio 2.18 (95% confidence interval 1.03 to 4.62); p = 0.043). The association between DDRP germline mutation carriers and risk of radiation-induced CBC seemed to be strongest in women who developed their second primary breast tumour at least 5 years after radiotherapy. Those patients had an odds ratio of 2.51 (95% confidence interval 1.03 to 6.10; p = 0.049) of developing radiation-induced breast cancer, in comparison with non-carriers.This study shows that carriers of germline mutations in a DDRP gene have an increased risk of developing (contralateral) breast cancer after radiotherapy; that is, over and above the risk associated with their carrier status. The increased risk indicates that knowledge of germline status of these DDRP genes at the time of breast cancer diagnosis may have important implications for the choice of treatment.Several risk factors for the development of breast cancer, such as family history, reproductive factors and exposure to radiation, have been identified. Out of all breast cancers, 5 to 10% can be attributed to germline mutations in familial high-risk genes such as BRCA1 or BRCA2 that result in a lifetime breast cancer risk of about 45 to 65% [1]. The penetrance varies between families, depending on 'risk modifiers' such as h
Multicomponent Density-Functional Theory for Electrons and Nuclei
Thomas Kreibich,Robert van Leeuwen,E. K. U. Gross
Physics , 2006,
Abstract: We present a general multi-component density functional theory in which electrons and nuclei are treated completely quantum mechanically, without the use of a Born-Oppenheimer approximation. The two fundamental quantities in terms of which our theory is formulated are the nuclear N-body density and the electron density expressed in coordinates referring to the nuclear framework. For these two densities coupled Kohn-Sham equations are derived and the electron-nuclear correlation functional is analyzed in detail. The formalism is tested on the hydrogen molecule $H_2$ and its positive ion $H_2^+$ using several approximations for the electron-nuclear correlation functional.
Exact Density-Functionals with Initial-State Dependence and Memory
M. Ruggenthaler,S. E. B. Nielsen,R. van Leeuwen
Physics , 2012, DOI: 10.1103/PhysRevA.88.022512
Abstract: We analytically construct the wave function that, for a given initial state, produces a prescribed density for a quantum ring with two non-interacting particles in a singlet state. In this case the initial state is completely determined by the initial density, the initial time-derivative of the density and a single integer that characterizes the (angular) momentum of the system. We then give an exact analytic expression for the exchange-correlation potential that relates two non-interacting systems with different initial states. This is used to demonstrate how the Kohn-Sham procedure predicts the density of a reference system without the need of solving the reference system's Schr\"odinger equation. We further numerically construct the exchange-correlation potential for an analytically solvable system of two electrons on a quantum ring with a squared cosine two-body interaction. For the same case we derive an explicit analytic expression for the exchange-correlation kernel and analyze its frequency-dependence (memory) in detail. We compare the result to simple adiabatic approximations and investigate the single-pole approximation. These approximations fail to describe the doubly-excited states, but perform well in describing the singly-excited states.
Local Control and v-Representability of Correlated Quantum Dynamics
S. E. B. Nielsen,M. Ruggenthaler,R. van Leeuwen
Physics , 2012, DOI: 10.1209/0295-5075/101/33001
Abstract: We present a local control scheme to construct the external potential v that, for a given initial state, produces a prescribed time-dependent density in an interacting quantum many-body system. The numerical method is efficient and stable even for large and rapid density variations irrespective of the initial state and the interactions. The method can at the same time be used to answer fundamental v-representability questions in density-functional theory. In particular, in the absence of interactions, it allows us to construct the exact time-dependent Kohn-Sham potential for arbitrary initial states. We illustrate the method in a correlated one-dimensional two-electron system with different interactions, initial states and densities. For a Kohn-Sham system with a correlated initial state we demonstrate the interplay between memory and initial-state dependence as well as the failure of any adiabatic approximation.
Magnetophoresis in the Rubinstein-Duke model
A. Drzewinski,E. Carlon,J. M. J. van Leeuwen
Physics , 2003, DOI: 10.1103/PhysRevE.68.061801
Abstract: We consider the magnetophoresis problem within the Rubinstein-Duke model, i.e. a reptating polymer pulled by a constant field applied to a single repton at the edge of a chain. Extensive density matrix renormalization calculations are presented of the drift velocity and the profile of the chain for various strengths of the driving field and chain lengths. We show that the velocities and the average densities of stored length are well described by simple interpolating crossover formulae, derived under the assumption that the difference between the drift and curvilinear velocities vanishes for sufficiently long chains. The profiles, which describe the average shape of the reptating chain, also show interesting features as some non-monotonic behavior of the links densities for sufficiently strong pulling fields. We develop a description in which a distinction is made between links entering at the pulled head and at the unpulled tail. At weak fields the separation between the head zone and the tail zone meanders through the whole chain, while the probability of finding it close to the edges drops off. At strong fields the tail zone is confined to a small region close to the unpulled edge of the polymer.
First-principles nonequilibrium Green's function approach to transient photoabsorption: Application to atoms
E. Perfetto,A. -M. Uimonen,R. van Leeuwen,G. Stefanucci
Physics , 2015, DOI: 10.1103/PhysRevA.92.033419
Abstract: We put forward a first-principle NonEquilibrium Green's Function (NEGF) approach to calculate the transient photoabsorption spectrum of optically thin samples. The method can deal with pump fields of arbitrary strength, frequency and duration as well as for overlapping and nonoverlapping pump and probe pulses. The electron-electron repulsion is accounted for by the correlation self-energy, and the resulting numerical scheme deals with matrices that scale quadratically with the system size. Two recent experiments, the first on helium and the second on krypton, are addressed. For the first experiment we explain the bending of the Autler-Townes absorption peaks with increasing the pump-probe delay $\t$, and relate the bending to the thickness and density of the gas. For the second experiment we find that sizable spectral structures of the pump-generated admixture of Kr ions are fingerprints of {\em dynamical correlation} effects, and hence they cannot be reproduced by time-local self-energy approximations. Remarkably, the NEGF approach also captures the retardation of the absorption onset of Kr$^{2+}$ with respect to Kr$^{1+}$ as a function of $\t$.
Subtyping of Breast Cancer by Immunohistochemistry to Investigate a Relationship between Subtype and Short and Long Term Survival: A Collaborative Analysis of Data for 10,159 Cases from 12 Studies
Fiona M. Blows equal contributor,Kristy E. Driver equal contributor,Marjanka K. Schmidt,Annegien Broeks,Flora E. van Leeuwen,Jelle Wesseling,Maggie C. Cheang,Karen Gelmon,Torsten O. Nielsen,Carl Blomqvist,P?ivi Heikkil?,Tuomas Heikkinen,Heli Nevanlinna,Lars A. Akslen,Louis R. Bégin,William D. Foulkes,Fergus J. Couch,Xianshu Wang,Vicky Cafourek,Janet E. Olson,Laura Baglietto,Graham G. Giles,Gianluca Severi,Catriona A. McLean,Melissa C. Southey,Emad Rakha,Andrew R. Green,Ian O. Ellis,Mark E. Sherman,Jolanta Lissowska,William F. Anderson,Angela Cox,Simon S. Cross,Malcolm W. R. Reed,Elena Provenzano,Sarah-Jane Dawson,Alison M. Dunning,Manjeet Humphreys,Douglas F. Easton,Montserrat García-Closas,Carlos Caldas,Paul D. Pharoah ,David Huntsman
PLOS Medicine , 2010, DOI: 10.1371/journal.pmed.1000279
Abstract: Background Immunohistochemical markers are often used to classify breast cancer into subtypes that are biologically distinct and behave differently. The aim of this study was to estimate mortality for patients with the major subtypes of breast cancer as classified using five immunohistochemical markers, to investigate patterns of mortality over time, and to test for heterogeneity by subtype. Methods and Findings We pooled data from more than 10,000 cases of invasive breast cancer from 12 studies that had collected information on hormone receptor status, human epidermal growth factor receptor-2 (HER2) status, and at least one basal marker (cytokeratin [CK]5/6 or epidermal growth factor receptor [EGFR]) together with survival time data. Tumours were classified as luminal and nonluminal tumours according to hormone receptor expression. These two groups were further subdivided according to expression of HER2, and finally, the luminal and nonluminal HER2-negative tumours were categorised according to expression of basal markers. Changes in mortality rates over time differed by subtype. In women with luminal HER2-negative subtypes, mortality rates were constant over time, whereas mortality rates associated with the luminal HER2-positive and nonluminal subtypes tended to peak within 5 y of diagnosis and then decline over time. In the first 5 y after diagnosis the nonluminal tumours were associated with a poorer prognosis, but over longer follow-up times the prognosis was poorer in the luminal subtypes, with the worst prognosis at 15 y being in the luminal HER2-positive tumours. Basal marker expression distinguished the HER2-negative luminal and nonluminal tumours into different subtypes. These patterns were independent of any systemic adjuvant therapy. Conclusions The six subtypes of breast cancer defined by expression of five markers show distinct behaviours with important differences in short term and long term prognosis. Application of these markers in the clinical setting could have the potential to improve the targeting of adjuvant chemotherapy to those most likely to benefit. The different patterns of mortality over time also suggest important biological differences between the subtypes that may result in differences in response to specific therapies, and that stratification of breast cancers by clinically relevant subtypes in clinical trials is urgently required. Please see later in the article for the Editors' Summary
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