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Dive into the research topics where Fred C.G.J. Sweep is active.

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Featured researches published by Fred C.G.J. Sweep.


Journal of Clinical Oncology | 2010

American Society of Clinical Oncology/College of American Pathologists Guideline Recommendations for Immunohistochemical Testing of Estrogen and Progesterone Receptors in Breast Cancer

M. Elizabeth H. Hammond; Daniel F. Hayes; Mitch Dowsett; D. Craig Allred; Karen L. Hagerty; Sunil Badve; Patrick L. Fitzgibbons; Glenn Duval Francis; Neil S. Goldstein; Malcolm M. Hayes; David G. Hicks; Susan Lester; Pamela B. Mangu; Lisa M. McShane; Keith W. Miller; C. Kent Osborne; Soonmyung Paik; Jane Perlmutter; Anthony Rhodes; Hironobu Sasano; Jared N. Schwartz; Fred C.G.J. Sweep; Sheila E. Taube; Emina Torlakovic; Paul N. Valenstein; Giuseppe Viale; Daniel W. Visscher; Thomas M. Wheeler; R. Bruce Williams; James L. Wittliff

PURPOSE To develop a guideline to improve the accuracy of immunohistochemical (IHC) estrogen receptor (ER) and progesterone receptor (PgR) testing in breast cancer and the utility of these receptors as predictive markers. METHODS The American Society of Clinical Oncology and the College of American Pathologists convened an international Expert Panel that conducted a systematic review and evaluation of the literature in partnership with Cancer Care Ontario and developed recommendations for optimal IHC ER/PgR testing performance. RESULTS Up to 20% of current IHC determinations of ER and PgR testing worldwide may be inaccurate (false negative or false positive). Most of the issues with testing have occurred because of variation in preanalytic variables, thresholds for positivity, and interpretation criteria. RECOMMENDATIONS The Panel recommends that ER and PgR status be determined on all invasive breast cancers and breast cancer recurrences. A testing algorithm that relies on accurate, reproducible assay performance is proposed. Elements to reliably reduce assay variation are specified. It is recommended that ER and PgR assays be considered positive if there are at least 1% positive tumor nuclei in the sample on testing in the presence of expected reactivity of internal (normal epithelial elements) and external controls. The absence of benefit from endocrine therapy for women with ER-negative invasive breast cancers has been confirmed in large overviews of randomized clinical trials.


Nature Communications | 2015

Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis (vol 5, 4926, 2014)

Beben Benyamin; Tonu Esko; Janina S. Ried; Aparna Radhakrishnan; Sita H. Vermeulen; Michela Traglia; Martin Goegele; Denise Anderson; Linda Broer; Clara Podmore; Jian'an Luan; Zoltán Kutalik; Serena Sanna; Peter van der Meer; Toshiko Tanaka; Fudi Wang; Harm-Jan Westra; Lude Franke; Evelin Mihailov; Lili Milani; Jonas Haelldin; Juliane Winkelmann; Thomas Meitinger; Joachim Thiery; Annette Peters; Melanie Waldenberger; Augusto Rendon; Jennifer Jolley; Jennifer Sambrook; Lambertus A. Kiemeney

Corrigendum: Novel loci affecting iron homeostasis and their effects in individuals at risk for hemochromatosis


Journal of Clinical Oncology | 2006

Multicenter Validation of a Gene Expression–Based Prognostic Signature in Lymph Node–Negative Primary Breast Cancer

John A. Foekens; David Atkins; Yi Zhang; Fred C.G.J. Sweep; Nadia Harbeck; Angelo Paradiso; Tanja Cufer; Anieta M. Sieuwerts; Dmitri Talantov; Paul N. Span; Vivianne C. G. Tjan-Heijnen; Alfredo Zito; Katja Specht; Heinz Hoefler; Rastko Golouh; Francesco Schittulli; Manfred Schmitt; Louk V.A.M. Beex; J.G.M. Klijn; Yixin Wang

PURPOSE We previously identified in a single-center study a 76-gene prognostic signature for lymph node-negative (LNN) breast cancer patients. The aim of this study was to validate this gene signature in an independent more diverse population of LNN patients from multiple institutions. PATIENTS AND METHODS Using custom-designed DNA chips we analyzed the expression of the 76 genes in RNA of frozen tumor samples from 180 LNN patients who did not receive adjuvant systemic treatment. RESULTS In this independent validation, the 76-gene signature was highly informative in identifying patients with distant metastasis within 5 years (hazard ratio, [HR], 7.41; 95% CI, 2.63 to 20.9), even when corrected for traditional prognostic factors in multivariate analysis (HR, 11.36; 95% CI, 2.67 to 48.4). The actuarial 5- and 10-year distant metastasis-free survival were 96% (95% CI, 89% to 99%) and 94% (95% CI, 83% to 98%), respectively, for the good profile group and 74% (95% CI, 64% to 81%) and 65% (53% to 74%), respectively for the poor profile group. The sensitivity for 5-yr distant metastasis-free survival was 90%, and the specificity was 50%. The positive and negative predictive values were 38% (95% CI, 29% to 47%) and 94% (95% CI, 86% to 97%), respectively. The 76-gene signature was confirmed as a strong prognostic factor in subgroups of estrogen receptor-positive patients, pre- and postmenopausal patients, and patients with tumor sizes 20 mm or smaller. The subgroup of patients with estrogen receptor-negative tumors was considered too small to perform a separate analysis. CONCLUSION Our data provide a strong methodologic and clinical multicenter validation of the predefined prognostic 76-gene signature in LNN breast cancer patients.


The EMBO Journal | 2009

ChIP-Seq of ERalpha and RNA polymerase II defines genes differentially responding to ligands.

Willem-Jan Welboren; Marc A. van Driel; Eva M. Janssen-Megens; Simon J. van Heeringen; Fred C.G.J. Sweep; Paul N. Span; Hendrik G. Stunnenberg

We used ChIP‐Seq to map ERα‐binding sites and to profile changes in RNA polymerase II (RNAPII) occupancy in MCF‐7 cells in response to estradiol (E2), tamoxifen or fulvestrant. We identify 10 205 high confidence ERα‐binding sites in response to E2 of which 68% contain an estrogen response element (ERE) and only 7% contain a FOXA1 motif. Remarkably, 596 genes change significantly in RNAPII occupancy (59% up and 41% down) already after 1 h of E2 exposure. Although promoter proximal enrichment of RNAPII (PPEP) occurs frequently in MCF‐7 cells (17%), it is only observed on a minority of E2‐regulated genes (4%). Tamoxifen and fulvestrant partially reduce ERα DNA binding and prevent RNAPII loading on the promoter and coding body on E2‐upregulated genes. Both ligands act differently on E2‐downregulated genes: tamoxifen acts as an agonist thus downregulating these genes, whereas fulvestrant antagonizes E2‐induced repression and often increases RNAPII occupancy. Furthermore, our data identify genes preferentially regulated by tamoxifen but not by E2 or fulvestrant. Thus (partial) antagonist loaded ERα acts mechanistically different on E2‐activated and E2‐repressed genes.


Hypertension | 2010

Carotid Baroreceptor Stimulation, Sympathetic Activity, Baroreflex Function, and Blood Pressure in Hypertensive Patients

Karsten Heusser; Jens Tank; Stefan Engeli; André Diedrich; Jan Menne; Siegfried Eckert; Timothy J. Peters; Fred C.G.J. Sweep; Hermann Haller; Andreas M. Pichlmaier; Friedrich C. Luft; Jens Jordan

In animals, electric field stimulation of carotid baroreceptors elicits a depressor response through sympathetic inhibition. We tested the hypothesis that the stimulation acutely reduces sympathetic vasomotor tone and blood pressure in patients with drug treatment–resistant arterial hypertension. Furthermore, we tested whether the stimulation impairs the physiological baroreflex regulation. We studied 7 men and 5 women (ages 43 to 69 years) with treatment-resistant arterial hypertension. A bilateral electric baroreflex stimulator at the level of the carotid sinus (Rheos) was implanted ≥1 month before the study. We measured intra-arterial blood pressure, heart rate, muscle sympathetic nerve activity (microneurography), cardiac baroreflex sensitivity (cross-spectral analysis and sequence method), sympathetic baroreflex sensitivity (threshold technique), plasma renin, and norepinephrine concentrations. Measurements were performed under resting conditions, with and without electric baroreflex stimulation, for ≥6 minutes during the same experiment. Intra-arterial blood pressure was 193±9/94±5 mm Hg on medications. Acute electric baroreflex stimulation decreased systolic blood pressure by 32±10 mm Hg (range: +7 to −108 mm Hg; P=0.01). The depressor response was correlated with a muscle sympathetic nerve activity reduction (r2=0.42; P<0.05). In responders, muscle sympathetic nerve activity decreased sharply when electric stimulation started. Then, muscle sympathetic nerve activity increased but remained below the baseline level throughout the stimulation period. Heart rate decreased 4.5±1.5 bpm with stimulation (P<0.05). Plasma renin concentration decreased 20±8% (P<0.05). Electric field stimulation of carotid sinus baroreflex afferents acutely decreased arterial blood pressure in hypertensive patients, without negative effects on physiological baroreflex regulation. The depressor response was mediated through sympathetic inhibition.


Archives of Pathology & Laboratory Medicine | 2010

American Society of Clinical oncology/college of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer

M. Elizabeth H. Hammond; Daniel F. Hayes; Mitch Dowsett; D. Craig Allred; Karen L. Hagerty; Sunil Badve; Patrick L. Fitzgibbons; Glenn Duval Francis; Neil S. Goldstein; Malcolm M. Hayes; David G. Hicks; Susan Lester; Pamela B. Mangu; Lisa M. McShane; Keith W. Miller; C. Kent Osborne; Soonmyung Paik; Jane Perlmutter; Anthony Rhodes; Hironobu Sasano; Jared N. Schwartz; Fred C.G.J. Sweep; Sheila E. Taube; Emina Torlakovic; Paul N. Valenstein; Giuseppe Viale; Daniel W. Visscher; Thomas M. Wheeler; R. Bruce Williams; James L. Wittliff

PURPOSE To develop a guideline to improve the accuracy of immunohistochemical (IHC) estrogen receptor (ER) and progesterone receptor (PgR) testing in breast cancer and the utility of these receptors as predictive markers. METHODS The American Society of Clinical Oncology and the College of American Pathologists convened an international Expert Panel that conducted a systematic review and evaluation of the literature in partnership with Cancer Care Ontario and developed recommendations for optimal IHC ER/PgR testing performance. RESULTS Up to 20% of current IHC determinations of ER and PgR testing worldwide may be inaccurate (false negative or false positive). Most of the issues with testing have occurred because of variation in preanalytic variables, thresholds for positivity, and interpretation criteria. RECOMMENDATIONS The Panel recommends that ER and PgR status be determined on all invasive breast cancers and breast cancer recurrences. A testing algorithm that relies on accurate, reproducible assay performance is proposed. Elements to reliably reduce assay variation are specified. It is recommended that ER and PgR assays be considered positive if there are at least 1% positive tumor nuclei in the sample on testing in the presence of expected reactivity of internal (normal epithelial elements) and external controls. The absence of benefit from endocrine therapy for women with ER-negative invasive breast cancers has been confirmed in large overviews of randomized clinical trials.


Hypertension | 2012

Catheter-Based Renal Nerve Ablation and Centrally Generated Sympathetic Activity in Difficult-to-Control Hypertensive Patients Prospective Case Series

Julia Brinkmann; Karsten Heusser; Bernhard M.W. Schmidt; Jan Menne; Gunnar Klein; Johann Bauersachs; Hermann Haller; Fred C.G.J. Sweep; André Diedrich; Jens Jordan; Jens Tank

Endovascular renal nerve ablation has been developed to treat resistant hypertension. In addition to lowering efferent renal sympathetic activation, the intervention may attenuate central sympathetic outflow through decreased renal afferent nerve traffic, as evidenced by a recent case report. We tested the hypothesis in 12 nonpreselected patients with difficult-to-control hypertension (aged 45–74 years) admitted for renal nerve ablation. All patients received ≥3 antihypertensive medications at full doses, including a diuretic. Electrocardiogram, respiration, brachial and finger arterial blood pressure, and muscle sympathetic nerve activity were recorded before and 3 to 6 months after renal nerve ablation. Heart rate and blood pressure variability were analyzed in the time and frequency domain. Pharmacological baroreflex slopes were determined using the modified Oxford bolus technique. Resting heart rate was 61±3 bpm before and 58±2 bpm after ablation (P=0.4). Supine blood pressure was 157±7/85±4 mm Hg before and 157±6/85±4 mm Hg after ablation (P=1.0). Renal nerve ablation did not change resting muscle sympathetic nerve activity (before, 34±2 bursts per minute; after, 32±3 bursts per minute P=0.6), heart rate variability, or blood pressure variability. Pharmacological baroreflex control of heart rate and muscle sympathetic nerve activity did not change. We conclude that reduced central sympathetic inhibition may be the exception rather than the rule after renal nerve ablation in unselected patients with difficult-to-control arterial hypertension.


Psychoneuroendocrinology | 1998

Cardiovascular and endocrine responses to experimental stress: Effects of mental effort and controllability

Madelon L. Peters; Guido L. R. Godaert; Rudy E. Ballieux; Marja van Vliet; Jacques J. Willemsen; Fred C.G.J. Sweep; Cobi J. Heijnen

The objective of the study was to investigate the unique and interactive effects of the controllability of a task and mental effort required by that task on cardiovascular and endocrine reactivity, when both were manipulated independently. A 2 x 2 factorial design was used, with two levels of mental effort and two levels of control. Twenty-four healthy male subjects participated in each experimental condition. Heart rate, blood pressure, catecholamine and cortisol responses were determined. High effort lead to greater increases in heart rate, blood pressure and norepinephrine levels. Uncontrollability lead to higher cortisol, blood pressure and norepinephrine responses. In addition, there was an effort x control interaction effect on the diastolic blood pressure response. In conclusion, effort has clear sympathetic effects, whereas control influences both the sympathetic nervous system and the release of cortisol. Having control seems to be most beneficial in high effort situations, at least with respect to sympathetic reactivity.


AIDS Research and Human Retroviruses | 2008

Vitamin D Deficiency among HIV Type 1-Infected Individuals in the Netherlands: Effects of Antiretroviral Therapy

Carolien J.P. Van Den Bout-Van Den Beukel; Lydia Fievez; Meta Michels; Fred C.G.J. Sweep; A.R.M.M. Hermus; Marjolein Bosch; David M. Burger; Bert Bravenboer; Peter P. Koopmans; Andre van der Ven

Vitamin D regulates bone metabolism but has also immunoregulatory properties. In HIV-infected patients bone disorders are increasingly observed. Furthermore, low 1,25(OH)(2)D(3) levels have been associated with low CD4(+) counts, immunological hyperactivity, and AIDS progression rates. Few studies have examined the vitamin D status in HIV-infected patients. This study will specifically focus on the effects of antiretroviral agents on vitamin D status. Furthermore, the effect of vitamin D status on CD4 cell recovery after initiation of HAART will be evaluated. Among 252 included patients the prevalence of vitamin D deficiency (<35 nmol/liter from April to September and <25 nmol/liter from October to March) was 29%. Female sex, younger age, dark skin, and NNRTI treatment were significant risk factors in univariate analysis, although in multivariate analyses skin pigmentation remained the only independent risk factor. Median 25(OH)D(3) levels were significantly lower in white NNRTI-treated patients [54.5(27.9-73.8) nmol/liter] compared to white PI-treated patients [77.3 (46.6-100.0) nmol/liter, p = 0.007], while among nonwhites no difference was observed. Both PI- and NNRTI-treated patients had significantly higher blood PTH levels than patients without treatment. Moreover, NNRTI treatment puts patients at risk of elevated PTH levels (>6.5 pmol/liter). Linear regression analysis showed that vitamin D status did not affect CD4 cell recovery after initiation of HAART. In conclusion, 29% of the HIV-1-infected patients had vitamin D deficiency, with skin color as an independent risk factor. NNRTI treatment may add more risk for vitamin D deficiency. Both PI- and NNRTI-treated patients showed higher PTH levels and might therefore be at risk of bone problems. Evaluation of 25(OH)D(3) and PTH levels, especially in NNRTI-treated and dark skinned HIV-1-infected patients, is necessary to detect and treat vitamin D deficiency early.


Blood | 2011

Serum hepcidin: reference ranges and biochemical correlates in the general population.

Tessel E. Galesloot; Sita H. Vermeulen; Anneke Geurts-Moespot; Siem M. Klaver; Joyce J.C. Kroot; D. van Tienoven; Jack F.M. Wetzels; Lambertus A. Kiemeney; Fred C.G.J. Sweep; M. den Heijer; Dorine W. Swinkels

To date, concentrations of the promising biomarker hepcidin have only been assessed in serum of relatively small series of healthy volunteers and patients. We assessed age- and sex-stratified reference ranges of serum hepcidin concentration in a selected reference set and performed regression analyses to study associations between hepcidin and (biochemical) variables in a large, well-phenotyped sample of the general population (n = 2998). All participants filled out a questionnaire on lifestyle, health status, and medical history. Serum measurements of iron parameters, liver enzyme alanine aminotransferase, creatinine and C-reactive protein were available. Serum hepcidin concentrations were lower for premenopausal than for postmenopausal women (median, 4.1 nM vs 8.5 nM, respectively). Hepcidin concentrations in men were constant over age (median, 7.8 nM). Serum hepcidin was strongly associated with serum ferritin in men and women: β-coefficient of log-transformed variables (95% confidence interval): 0.78 (0.74-0.82) and 0.83 (0.78-0.88), respectively. Additional significant, though less strong, associations were observed for C-reactive protein and total iron binding capacity in men and for total iron binding capacity, alanine aminotransferase, and glomerular filtration rate in women. Our study provides age- and sex-specific reference ranges of serum hepcidin concentration and indicates ferritin as the primary correlate of serum hepcidin concentration.

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Paul N. Span

Radboud University Nijmegen

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John A. Foekens

Erasmus University Rotterdam

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Chris M.G. Thomas

Radboud University Nijmegen

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A.R.M.M. Hermus

Radboud University Nijmegen

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Johan Bussink

Radboud University Nijmegen Medical Centre

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John W.M. Martens

Erasmus University Rotterdam

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H. Alec Ross

Radboud University Nijmegen Medical Centre

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Maxime P. Look

Erasmus University Rotterdam

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