255 research outputs found

    No Effect of Folic Acid Supplementation on Global DNA Methylation in Men and Women with Moderately Elevated Homocysteine

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    A global loss of cytosine methylation in DNA has been implicated in a wide range of diseases. There is growing evidence that modifications in DNA methylation can be brought about by altering the intake of methyl donors such as folate. We examined whether long-term daily supplementation with 0.8 mg of folic acid would increase global DNA methylation compared with placebo in individuals with elevated plasma homocysteine. We also investigated if these effects were modified by MTHFR C677T genotype. Two hundred sixteen participants out of 818 subjects who had participated in a randomized double-blind placebo-controlled trial were selected, pre-stratified on MTHFR C677T genotype and matched on age and smoking status. They were allocated to receive either folic acid (0.8 mg/d; n = 105) or placebo treatment (n = 111) for three years. Peripheral blood leukocyte DNA methylation and serum and erythrocyte folate were assessed. Global DNA methylation was measured using liquid chromatography-tandem mass spectrometry and expressed as a percentage of 5-methylcytosines versus the total number of cytosine. There was no difference in global DNA methylation between those randomized to folic acid and those in the placebo group (difference = 0.008, 95%CI = −0.05,0.07, P = 0.79). There was also no difference between treatment groups when we stratified for MTHFR C677T genotype (CC, n = 76; CT, n = 70; TT, n = 70), baseline erythrocyte folate status or baseline DNA methylation levels. In moderately hyperhomocysteinemic men and women, long-term folic acid supplementation does not increase global DNA methylation in peripheral blood leukocytes

    Hyperthermia treatment planning including convective flow in cerebrospinal fluid for brain tumour hyperthermia treatment using a novel dedicated paediatric brain applicator

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    Hyperthermia therapy (40–44 \ub0C) is a promising option to increase efficacy of radiotherapy/chemotherapy for brain tumours, in particular paediatric brain tumours. The Chalmers Hyperthermia Helmet is developed for this purpose. Hyperthermia treatment planning is required for treatment optimisation, but current planning systems do not involve a physically correct model of cerebrospinal fluid (CSF). This study investigates the necessity of fluid modelling for treatment planning. We made treatments plans using the Helmet for both pre-operative and post-operative cases, comparing temperature distributions predicted with three CSF models: A convective “fluid” model, a non-convective “solid” CSF model, and CSF models with increased effective thermal conductivity (“high-k”). Treatment plans were evaluated by T90, T50 and T10 target temperatures and treatment-limiting hot spots. Adequate heating is possible with the helmet. In the pre-operative case, treatment plan quality was comparable for all three models. In the post-operative case, the high-k models were more accurate than the solid model. Predictions to within \ub11 \ub0C were obtained by a 10–20-fold increased effective thermal conductivity. Accurate modelling of the temperature in CSF requires fluid dynamics, but modelling CSF as a solid with enhanced effective thermal conductivity might be a practical alternative for a convective fluid model for many applications

    Thermal dosimetry for bladder hyperthermia treatment. An overview.

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    The urinary bladder is a fluid-filled organ. This makes, on the one hand, the internal surface of the bladder wall relatively easy to heat and ensures in most cases a relatively homogeneous temperature distribution; on the other hand the variable volume, organ motion, and moving fluid cause artefacts for most non-invasive thermometry methods, and require additional efforts in planning accurate thermal treatment of bladder cancer. We give an overview of the thermometry methods currently used and investigated for hyperthermia treatments of bladder cancer, and discuss their advantages and disadvantages within the context of the specific disease (muscle-invasive or non-muscle-invasive bladder cancer) and the heating technique used. The role of treatment simulation to determine the thermal dose delivered is also discussed. Generally speaking, invasive measurement methods are more accurate than non-invasive methods, but provide more limited spatial information; therefore, a combination of both is desirable, preferably supplemented by simulations. Current efforts at research and clinical centres continue to improve non-invasive thermometry methods and the reliability of treatment planning and control software. Due to the challenges in measuring temperature across the non-stationary bladder wall and surrounding tissues, more research is needed to increase our knowledge about the penetration depth and typical heating pattern of the various hyperthermia devices, in order to further improve treatments. The ability to better determine the delivered thermal dose will enable clinicians to investigate the optimal treatment parameters, and consequentially, to give better controlled, thus even more reliable and effective, thermal treatments

    DNA methylation and cognitive functioning in healthy older adults

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    Long-term supplementation with folic acid may improve cognitive performance in older individuals. The relationship between folate status and cognitive performance might be mediated by changes in methylation capacity, as methylation reactions are important for normal functioning of the brain. Although aberrant DNA methylation has been implicated in neurodevelopmental disorders, the relationship between DNA methylation status and non-pathological cognitive functioning in human subjects has not yet been investigated. The present study investigated the associations between global DNA methylation and key domains of cognitive functioning in healthy older adults. Global DNA methylation, defined as the percentage of methylated cytosine to total cytosine, was measured in leucocytes by liquid chromatography-MS/MS, in 215 men and women, aged 50-70 years, who participated in the Folic Acid and Carotid Intima-Media Thickness (FACIT) study (clinical trial registration number NCT00110604). Cognitive performance was assessed by means of the Visual Verbal Word Learning Task, the Stroop Colour-Word Interference Test, the Concept Shifting Test, the Letter-Digit Substitution Test and the Verbal Fluency Test. Using hierarchical linear regression analyses adjusted for age, sex, level of education, alcohol consumption, smoking status, physical activity, erythrocyte folate concentration and 5,10-methylenetetrahydrofolate reductase 677C→T genotype, we found that global DNA methylation was not related to cognitive performance on any of the domains measured. The present study results do not support the hypothesis that global DNA methylation, as measured in leucocytes, might be associated with cognitive functioning in healthy older individual

    Heating technology for malignant tumors: a review

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    The therapeutic application of heat is very effective in cancer treatment. Both hyperthermia, i.e., heating to 39-45 degrees C to induce sensitization to radiotherapy and chemotherapy, and thermal ablation, where temperatures beyond 50 degrees C destroy tumor cells directly are frequently applied in the clinic. Achievement of an effective treatment requires high quality heating equipment, precise thermal dosimetry, and adequate quality assurance. Several types of devices, antennas and heating or power delivery systems have been proposed and developed in recent decades. These vary considerably in technique, heating depth, ability to focus, and in the size of the heating focus. Clinically used heating techniques involve electromagnetic and ultrasonic heating, hyperthermic perfusion and conductive heating. Depending on clinical objectives and available technology, thermal therapies can be subdivided into three broad categories: local, locoregional, or whole body heating. Clinically used local heating techniques include interstitial hyperthermia and ablation, high intensity focused ultrasound (HIFU), scanned focused ultrasound (SFUS), electroporation, nanoparticle heating, intraluminal heating and superficial heating. Locoregional heating techniques include phased array systems, capacitive systems and isolated perfusion. Whole body techniques focus on prevention of heat loss supplemented with energy deposition in the body, e.g., by infrared radiation. This review presents an overview of clinical hyperthermia and ablation devices used for local, locoregional, and whole body therapy. Proven and experimental clinical applications of thermal ablation and hyperthermia are listed. Methods for temperature measurement and the role of treatment planning to control treatments are discussed briefly, as well as future perspectives for heating technology for the treatment of tumors

    Determinants of radiographic progression in early psoriatic arthritis:Insights from a real-world cohort

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    Objective Persistent articular inflammation in psoriatic arthritis (PsA) is associated with radiographic damage. Despite advances in diagnosis and therapy, radiographic structural damage remains prevalent in PsA. To elucidate this topic, we studied which baseline clinical characteristics determine radiographic progression. Methods For this analysis, data were used from DEPAR (Dutch South West Psoriatic Arthritis) Study, a real-world cohort of patients with newly diagnosed PsA. Radiographic changes were assessed using the modified Total Sharp/van der Heijde Score (mTSS) for PsA. Univariable-multivariable mixed-effects negative binomial regression analysis was applied to define baseline predictors for radiographic progression over time. Results The study included 476 patients with early PsA with 1660 hand and feet radiographs from four different time points (baseline, first, second and third year). The progressive group (n=71) had a higher mTSS compared with the non-progressive group (n=405) at diagnosis (17 (3-36) vs 0 (0-1)). A comparison of the two groups revealed that the progressive group had significantly older (59 (12) vs 49 (13)) and a higher rate of the presence of swollen joints (93% vs 78%) at diagnosis. Multivariable analysis identified age (incidence rate ratio (IRR)=1.10, p=0.000), sex (female) (IRR=0.48, p=0.043) and baseline mTSS (IRR=1.11, p=0.000) as significant determinants of radiographic change over time. For the progressive subset, additionally, the multivariable analysis highlighted baseline Disease Activity in PSoriatic Arthritis (IRR=1.05, p=0.006) and swollen joint count (IRR=1.07, p=0.034) as predictors. Conclusions According to this real-world cohort, patients with early PsA exhibit minimal radiographic progression under current treatment protocols. This study indicates that while old age and initial radiographic damage predict progression, female sex confers a protective effect on it. Furthermore, disease activity score and swollen joints emerged as predictors for radiographic changes during the follow-up in progressive patients.</p

    Determinants of radiographic progression in early psoriatic arthritis:Insights from a real-world cohort

    Get PDF
    Objective Persistent articular inflammation in psoriatic arthritis (PsA) is associated with radiographic damage. Despite advances in diagnosis and therapy, radiographic structural damage remains prevalent in PsA. To elucidate this topic, we studied which baseline clinical characteristics determine radiographic progression. Methods For this analysis, data were used from DEPAR (Dutch South West Psoriatic Arthritis) Study, a real-world cohort of patients with newly diagnosed PsA. Radiographic changes were assessed using the modified Total Sharp/van der Heijde Score (mTSS) for PsA. Univariable-multivariable mixed-effects negative binomial regression analysis was applied to define baseline predictors for radiographic progression over time. Results The study included 476 patients with early PsA with 1660 hand and feet radiographs from four different time points (baseline, first, second and third year). The progressive group (n=71) had a higher mTSS compared with the non-progressive group (n=405) at diagnosis (17 (3-36) vs 0 (0-1)). A comparison of the two groups revealed that the progressive group had significantly older (59 (12) vs 49 (13)) and a higher rate of the presence of swollen joints (93% vs 78%) at diagnosis. Multivariable analysis identified age (incidence rate ratio (IRR)=1.10, p=0.000), sex (female) (IRR=0.48, p=0.043) and baseline mTSS (IRR=1.11, p=0.000) as significant determinants of radiographic change over time. For the progressive subset, additionally, the multivariable analysis highlighted baseline Disease Activity in PSoriatic Arthritis (IRR=1.05, p=0.006) and swollen joint count (IRR=1.07, p=0.034) as predictors. Conclusions According to this real-world cohort, patients with early PsA exhibit minimal radiographic progression under current treatment protocols. This study indicates that while old age and initial radiographic damage predict progression, female sex confers a protective effect on it. Furthermore, disease activity score and swollen joints emerged as predictors for radiographic changes during the follow-up in progressive patients.</p

    Paternal inflammatory arthritis is associated with a higher risk of miscarriage:results of a large multicentre study (iFAME-Fertility)

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    OBJECTIVES: Paternal preconception health is recognized as an important contributor to pregnancy outcomes. Nonetheless, pregnancy outcomes of partners of men with inflammatory arthritis (IA) have never been studied. Our objective was to describe the pregnancy outcomes of partners of men diagnosed with IA.METHODS: We performed a multicentre cross-sectional retrospective study conducted in the Netherlands. Men with IA who were over 40 years old that reported at least one positive pregnancy test were included. To analyse the impact of IA on pregnancy outcomes, pregnancies were classified into two groups: pregnancies conceived after the diagnosis of IA and before the diagnosis of IA.RESULTS: In total, 408 male participants diagnosed with IA reported 897 singleton pregnancies that resulted in 794 live births. Pregnancies conceived after the diagnosis of IA had higher rate of miscarriage (12.27 vs 7.53%, P = &lt;0.05). This increased risk was still present after adjusting for confounders [OR 2.03 (95% CI 1.12, 3.69) P = 0.015].CONCLUSIONS: This is the largest study to describe the pregnancy outcomes of partners of men diagnosed with IA and the first to demonstrate that paternal IA is associated with a higher risk of miscarriage. Notwithstanding, the overall rate of miscarriage reported in our study could be comparable to previously reported population estimates.</p

    Serum Iron Parameters, HFE C282Y Genotype, and Cognitive Performance in Older Adults: Results From the FACIT Study

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    Although iron homeostasis is essential for brain functioning, the effects of iron levels on cognitive performance in older individuals have scarcely been investigated. In the present study, serum iron parameters and hemochromatosis (HFE) C282Y genotype were determined in 818 older individuals who participated in a 3-year randomized, placebo-controlled double-blind trial examining the effects of folic acid on carotid intima-media thickness. All participants had slightly elevated homocysteine levels and were vitamin B12 replete. Cognitive functioning was assessed at baseline and after 3 years by means of a neuropsychological test battery. At baseline, increased serum ferritin was associated with decreased sensorimotor speed, complex speed, and information-processing speed and increased serum iron was associated with decreased sensorimotor speed. Cognitive performance over 3 years was not associated with HFE C282Y genotype or iron parameters. In conclusion, serum iron parameters do not show a straightforward relationship with cognitive functioning, although elevated iron levels may decrease cognitive speed in older individuals susceptible to cognitive impairmen
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