1,158 research outputs found

    Transient caloric restriction and cancer risk (The Netherlands)

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    Over the past century, many animal experiments have shown that caloric restriction can reduce the risk of cancer, a finding that proved to be highly reproducible. Many papers have been published on its potential for human health, but until know little evidence is available on its actual effects in humans. In Utrecht, The Netherlands, we have been investigating the effects of the 1944–1945 Dutch famine on breast cancer risk factors and breast cancer risk, and paradoxically the relatively short-term famine seemed to be related to increased breast cancer risk in later life. One of the differences between the famine situation and the large body of evidence from animal experiments is the duration of caloric restriction. Almost all animal experiments investigated sustained caloric restriction and information on the effects of short-term transient caloric restriction is very scarce. A search in the literature identified some animal experiments on short-term transient caloric restriction and these seemed to be at least supportive to the famine findings. Because caloric restriction in humans for preventive health measures would be mostly short-term, it is important to extend animal research on short-term caloric restriction

    Escherichia coli bacteriuria in female adults is associated with the development of hypertension

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    AbstractObjectiveTo investigate whether Escherichia coli bacteriuria is associated with the development of hypertension during a long-term follow-up.MethodsA prospective cohort study was performed among the participants of two population-based studies. Between 1974 and 1986 all women aged 39 to 68 years old, who lived in Utrecht, the Netherlands, were invited to participate in a breast cancer screening program. The participants completed a questionnaire, underwent a medical examination, and collected a morning urine sample that remained stored. From 1993 to 1997 another population-based study was performed. We performed a full cohort analysis for 444 women who participated in both studies. E. coli bacteriuria was diagnosed by a real-time PCR. Hypertension was defined as the use of antihypertensive medication and/or a measured systolic blood pressure of at least 160 mmHg or a diastolic blood pressure of 95 mmHg or higher. The mean follow-up was 11.5±1.7 years.ResultsForty women (9%) had E. coli bacteriuria at baseline. Women who had bacteriuria at baseline had a mean blood pressure at study endpoint of 133±20 mmHg systolic and 78±11 mmHg diastolic, and women without bacteriuria had values of 129±20 and 78±11 mmHg, respectively (p-values for difference 0.33 and 0.88). Although E. coli bacteriuria was not associated with the blood pressure as a continuous variable, it was associated with the development of hypertension during follow-up (OR 2.8, 95% CI 1.4–5.5).ConclusionE. coli bacteriuria may increase the risk of future hypertension

    Volumetric breast density affects performance of digital screening mammography

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    PURPOSE: To determine to what extent automatically measured volumetric mammographic density influences screening performance when using digital mammography (DM). METHODS: We collected a consecutive series of 111,898 DM examinations (2003-2011) from one screening unit of the Dutch biennial screening program (age 50-75 years). Volumetric mammographic density was automatically assessed using Volpara. We determined screening performance measures for four density categories comparable to the American College of Radiology (ACR) breast density categories. RESULTS: Of all the examinations, 21.6% were categorized as density category 1 ('almost entirely fatty') and 41.5, 28.9, and 8.0% as category 2-4 ('extremely dense'), respectively. We identified 667 screen-detected and 234 interval cancers. Interval cancer rates were 0.7, 1.9, 2.9, and 4.4‰ and false positive rates were 11.2, 15.1, 18.2, and 23.8‰ for categories 1-4, respectively (both p-trend < 0.001). The screening sensitivity, calculated as the proportion of screen-detected among the total of screen-detected and interval tumors, was lower in higher density categories: 85.7, 77.6, 69.5, and 61.0% for categories 1-4, respectively (p-trend < 0.001). CONCLUSIONS: Volumetric mammographic density, automatically measured on digital mammograms, impacts screening performance measures along the same patterns as established with ACR breast density categories. Since measuring breast density fully automatically has much higher reproducibility than visual assessment, this automatic method could help with implementing density-based supplemental screening

    Single-conformation spectroscopy of hydrogen bonding networks: Solvation, synthetic foldamers, and neurodegenerative diseases

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    The hydrogen bond is one of the most important interactions in natural processes ranging from protein folding to chemical reactions. Two complementary methodologies are applied to understanding this important interaction: top-down and bottom-up. Top-down methods use large molecules, such as proteins, revealing secondary structure information. Bottom-up experiments are performed on small molecules, utilizing high-resolution spectroscopy to reveal underlying quantum mechanical effects. The complexity gap is formed between these two experimental regimes; between large and small molecules; between bulk and individual solvent molecules; between classical mechanics calculations and quantum chemical calculations. This dissertation will focus on the application of gas phase, single-conformation ultraviolet (UV) and infrared (IR) spectroscopies to the study of molecules and clusters in the size and solvation complexity gap, with the goal of bridging the gulf between the two experimental approaches. Single-conformation spectroscopy is perfectly suited to study solvation. Solvent molecules, in many instances water, can be frozen onto the solute in a stepwise manner. Here, we solvate a prototypical flexible bichromophore—1,2-diphenoxyethane (DPOE)—by stepwise addition of water molecules. Single-conformation spectroscopy reveals both the structural perturbations associated with water molecule addition and their effect on DPOE’s pair of closely spaced excited electronic states. These experimental studies provide excellent insight into solvent effects on vibronic and excitonic coupling, and can be used to further develop the models used to describe such processes. Similarly, single-conformation spectroscopy can reveal the effects of conformational flexibility on the innate conformational preferences and hydrogen bonding motifs in peptides. Results obtained from a study of a cyclically constrained γ peptide, γACHC, reveal that increased conformational flexibility can be controlled by synthetic chemists in order to direct folding into pre-programmed secondary structures and that these structures are stabilized with intramolecular rather than intermolecular hydrogen bonds. This theme of conformational flexibility is continued in studies of glutamine containing peptides. Glutamine—with its flexible, hydrogen bond forming sidechain—is intimately involved with neurodegenerative diseases such as Huntington’s disease. Single-conformation studies help reveal the delicate interplay between three different types of hydrogen bonds within the molecule: backbone-backbone, sidechain-backbone, and sidechain-sidechain hydrogen bonds. The importance of these competing hydrogen bonds on the conformational preferences will be discussed both locally and within the larger context of disease pathogenesis

    Associations between lifestyle factors and an unhealthy diet.

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    : Unhealthy dietary patterns have been associated with other unhealthy lifestyle factors such as smoking and physical inactivity. Whether these associations are similar in high- and low-educated individuals is currently unknown

    Effect of diet with or without exercise on abdominal fat in postmenopausal women:A randomised trial

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    Background: We assessed the effect of equivalent weight loss with or without exercise on (intra-) abdominal fat in postmenopausal women in the SHAPE-2 study. Methods: The SHAPE-2 study is a three-armed randomised controlled trial conducted in 2012-2013 in the Netherlands. Postmenopausal overweight women were randomized to a diet (n = 97), exercise plus diet (n = 98) or control group (n = 48). Both intervention groups aimed for equivalent weight loss (6-7%) following a calorie-restricted diet (diet group) or a partly supervised intensive exercise programme (4 h per week) combined with a small caloric restriction (exercise plus diet group). Outcomes after 16 weeks are amount and distribution of abdominal fat, measured by magnetic resonance imaging (MRI) with the use of the three-point IDEAL Dixon method. Results: The diet and exercise plus diet group lost 6.1 and 6.9% body weight, respectively. Compared to controls, subcutaneous and intra-abdominal fat reduced significantly with both diet (- 12.5% and - 12.0%) and exercise plus diet (- 16.0% and - 14.6%). Direct comparison between both interventions revealed that the reduction in subcutaneous fat was statistically significantly larger in the group that combined exercise with diet: an additional 10.6 cm 2 (95%CI -18.7; - 2.4) was lost compared to the diet-only group. Intra-abdominal fat loss was not significantly larger in the exercise plus diet group (- 3.8 cm 2 , 95%CI -9.0; 1.3). Conclusions: We conclude that weight loss of 6-7% with diet or with exercise plus diet reduced both subcutaneous and intra-abdominal fat. Only subcutaneous fat statistically significantly reduced to a larger extent when exercise is combined with a small caloric restriction. Trial register: NCT01511276 (clinicaltrials.gov), prospectively registered

    Socio-ecological correlates of physical activity in breast and colon cancer survivors 4 years after participation in a randomized controlled exercise trial (PACT study)

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    Having a physically active lifestyle after cancer diagnosis is beneficial for health, and this needs to be continued into survivorship to optimize long-term benefits. We found that patients, who participated in an 18-week exercise intervention, reported significant higher physical activity (PA) levels 4 years after participation in a randomized controlled trial of supervised exercise delivered during chemotherapy (PACT study). This study aimed to identify social-ecological correlates of PA levels in breast and colon cancer survivors 4 years after participation in the PACT study. Methods Self-reported PA levels and potential correlates (e.g. physical fitness, fatigue, exercise history, and built environment) were assessed in 127 breast and colon cancer survivors shortly after diagnosis (baseline), post-intervention and 4 years later. Multivariable linear regression analyses were performed to identify social-ecological correlates of PA 4 years postbaseline. Results The final model revealed that lower baseline physical fatigue (ÎČ =-0.25, 95% CI-0.26;-0.24) and higher baseline total PA (0.06, 95% CI, 0.03; 0.10) were correlated with higher total PA levels 4 years post-baseline. Higher baseline leisure and sport PA (0.02, 95% CI 0.01; 0.03), more recreational facilities within a buffer of 1 km (4.05, 95% CI = 1.28; 6.83), lower physical fatigue at 4-year follow-up (-8.07, 95% CI-14.00;-2.1,3), and having a positive change in physical fatigue during the intervention period (0.04, 95% CI 0.001; 0.07) were correlates of sport and leisure PA levels 4 years post-baseline. Conclusions This study suggests that baseline and 4-year post-baseline physical fatigue, and past exercise behaviour, were significant correlates of PA 4 years after participation in an exercise trial. Additionally, this study suggests that the built environment should be taken into account when promoting PA. Understanding of socio-ecological correlates of PA can provide insights into how future exercise interventions should be designed to promote long-term exercise behaviour

    Lifestyle, dietary factors and antibody levels to oral bacteria in cancer-free participants of a European cohort study

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    Background—Increasing evidence suggests that oral microbiota play a pivotal role in chronic diseases, in addition to the well-established role in periodontal disease. Moreover, recent studies suggest that oral bacteria may also be involved in carcinogenesis; periodontal disease has been linked several cancers. In this study, we examined whether lifestyle factors have an impact on antibody levels to oral bacteria. Methods—Data on demographic characteristics, lifestyle factors, and medical conditions were obtained at the time of blood sample collection. For the current analysis, we measured antibody levels to 25 oral bacteria in 395 cancer-free individuals using an immunoblot array. Combined total immunglobin G (IgG) levels were obtained by summing concentrations for all oral bacteria measured. Results—IgG antibody levels were substantially lower among current and former smokers (1697 and 1677 ng/mL, respectively) than never smokers (1960 ng/mL; p-trend = 0.01), but did not vary by other factors, including BMI, diabetes, physical activity, or by dietary factors, after adjusting for age, sex, education, country and smoking status. The highest levels of total IgG were found among individuals with low education (2419 ng/mL). Conclusions—Our findings on smoking are consistent with previous studies and support the notion that smokers have a compromised humoral immune response. Moreover, other major factors known to be associated with inflammatory markers, including obesity, were not associated with antibody levels to a large number of oral bacteria
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