194 research outputs found

    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

    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

    Molecular imaging in oncology: the acceptance of PET/CT and the emergence of MR/PET imaging

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    In the last decade, PET-only systems have been phased out and replaced with PET-CT systems. This merger of a functional and anatomical imaging modality turned out to be extremely useful in clinical practice. Currently, PET-CT is a major diagnostic tool in oncology. At the dawn of the merger of MRI and PET, another breakthrough in clinical imaging is expected. The combination of these imaging modalities is challenging, but has particular features such as imaging biological processes at the same time in specific body locations

    Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with γ\gamma Beams of High Intensity and Large Brilliance

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    We study the production of radioisotopes for nuclear medicine in (γ,xn+yp)(\gamma,x{\rm n}+y{\rm p}) photonuclear reactions or (γ,γ\gamma,\gamma') photoexcitation reactions with high flux [(1013101510^{13}-10^{15})γ\gamma/s], small diameter (100μ\sim (100 \, \mum)2)^2 and small band width (ΔE/E103104\Delta E/E \approx 10^{-3}-10^{-4}) γ\gamma beams produced by Compton back-scattering of laser light from relativistic brilliant electron beams. We compare them to (ion,xxn+y + yp) reactions with (ion=p,d,α\alpha) from particle accelerators like cyclotrons and (n,γ\gamma) or (n,f) reactions from nuclear reactors. For photonuclear reactions with a narrow γ\gamma beam the energy deposition in the target can be managed by using a stack of thin target foils or wires, hence avoiding direct stopping of the Compton and pair electrons (positrons). (γ,γ)(\gamma,\gamma') isomer production via specially selected γ\gamma cascades allows to produce high specific activity in multiple excitations, where no back-pumping of the isomer to the ground state occurs. We discuss in detail many specific radioisotopes for diagnostics and therapy applications. Photonuclear reactions with γ\gamma beams allow to produce certain radioisotopes, e.g. 47^{47}Sc, 44^{44}Ti, 67^{67}Cu, 103^{103}Pd, 117m^{117m}Sn, 169^{169}Er, 195m^{195m}Pt or 225^{225}Ac, with higher specific activity and/or more economically than with classical methods. This will open the way for completely new clinical applications of radioisotopes. For example 195m^{195m}Pt could be used to verify the patient's response to chemotherapy with platinum compounds before a complete treatment is performed. Also innovative isotopes like 47^{47}Sc, 67^{67}Cu and 225^{225}Ac could be produced for the first time in sufficient quantities for large-scale application in targeted radionuclide therapy.Comment: submitted to Appl. Phys.

    Non-Hodgkin's lymphoma presenting as a primary bladder tumor: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Primary lymphoma of the bladder represents 0.2% of all bladder malignancies. Secondary involvement of the bladder by malignant lymphoma occurs in 10% to 50% of cases. Most lymphomas of the bladder are non-Hodgkin's lymphomas of the B-cell type, with preponderance among women. The impact of positron emission tomography (PET) on tumor staging has recently become very important due to its use in the study of diagnosis extension and individual therapy design.</p> <p>Case presentation</p> <p>We report the case of a 79-year-old Caucasian man with intermittent haematuria as the presenting symptom of non-Hodgkin's lymphoma of the bladder. He was first diagnosed with primary lymphoma of the bladder using the current staging method, but a positron emission tomography study subsequently revealed that he instead had a secondary involvement of the bladder.</p> <p>Conclusion</p> <p>The staging of non-Hodgkin's lymphomas, which is useful in order to plan accurate therapy, has been changing since the introduction of positron emission tomography scanning. Primary lymphomas of the bladder, although very rare, may be even more uncommon when this imaging technique is used to assess the extension of the disease. Although the interpretation of this technique has some limitations that should be taken into account, the extensive use of positron emission tomography should nonetheless help improve the diagnosis of this disease.</p
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