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1.
Automated segmentation of midbrain structures with high iron content.
Garzón, B, Sitnikov, R, Bäckman, L, Kalpouzos, G
NeuroImage. 2018;:199-209
Abstract
The substantia nigra (SN), the subthalamic nucleus (STN), and the red nucleus (RN) are midbrain structures of ample interest in many neuroimaging studies, which may benefit from the availability of automated segmentation methods. The high iron content of these structures awards them high contrast in quantitative susceptibility mapping (QSM) images. We present a novel segmentation method that leverages the information of these images to produce automated segmentations of the SN, STN, and RN. The algorithm builds a map of spatial priors for the structures by non-linearly registering a set of manually-traced training labels to the midbrain. The priors are used to inform a Gaussian mixture model of the image intensities, with smoothness constraints imposed to ensure anatomical plausibility. The method was validated on manual segmentations from a sample of 40 healthy younger and older subjects. Average Dice scores were 0.81 (0.05) for the SN, 0.66 (0.14) for the STN and 0.88 (0.04) for the RN in the left hemisphere, and similar values were obtained for the right hemisphere. In all structures, volumes of manual and automatically obtained segmentations were significantly correlated. The algorithm showed lower accuracy on R2* and T2-weighted Fluid Attenuated Inversion Recovery (FLAIR) images, which are also sensitive to iron content. To illustrate an application of the method, we show that the automated segmentations were comparable to the manual ones regarding detection of age-related differences to putative iron content.
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2.
Serum zinc, copper and iron status of children with coeliac disease on three months of gluten-free diet with or without four weeks of zinc supplements: a randomised controlled trial.
Negi, K, Kumar, R, Sharma, L, Datta, SP, Choudhury, M, Kumar, P
Tropical doctor. 2018;(2):112-116
Abstract
Data about the effect of zinc supplementation with gluten-free diet on normalisation of plasma zinc, copper and iron in patients with coeliac disease are scanty. We evaluated the effect of zinc supplementation on serum zinc, copper and iron levels in patients with coeliac disease, by randomising 71 children newly diagnosed with coeliac disease into two groups: Group A = gluten-free diet (GFD); and Group B = gluten-free diet with zinc supplements (GFD +Zn). The rise in iron and zinc was significantly higher in the latter, but the mean rise of copper levels was slightly higher in the former, but the difference was not significant.
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3.
Bioavailability of Mineral-Bound Iron to a Snow Algal-Bacterial Coculture and Implications for Albedo-Altering Snow Algal Blooms.
Harrold, ZR, Hausrath, EM, Garcia, AH, Murray, AE, Tschauner, O, Raymond, JA, Huang, S
Applied and environmental microbiology. 2018;(7)
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Abstract
Snow algae can form large-scale blooms across the snowpack surface and near-surface environments. These pigmented blooms can decrease snow albedo and increase local melt rates, and they may impact the global heat budget and water cycle. Yet, the underlying causes for the geospatial occurrence of these blooms remain unconstrained. One possible factor contributing to snow algal blooms is the presence of mineral dust as a micronutrient source. We investigated the bioavailability of iron (Fe)-bearing minerals, including forsterite (Fo90, Mg1.8Fe0.2SiO4), goethite, smectite, and pyrite as Fe sources for a Chloromonas brevispina-bacterial coculture through laboratory-based experimentation. Fo90 was capable of stimulating snow algal growth and increased the algal growth rate in otherwise Fe-depleted cocultures. Fo90-bearing systems also exhibited a decrease in the ratio of bacteria to algae compared to those of Fe-depleted conditions, suggesting a shift in microbial community structure. The C. brevispina coculture also increased the rate of Fo90 dissolution relative to that of an abiotic control. Analysis of 16S rRNA genes in the coculture identified Gammaproteobacteria, Betaproteobacteria, and Sphingobacteria, all of which are commonly found in snow and ice environments. Archaea were not detected. Collimonas and Pseudomonas, which are known to enhance mineral weathering rates, comprised two of the top eight (>1%) operational taxonomic units (OTUs). These data provide unequivocal evidence that mineral dust can support elevated snow algal growth under otherwise Fe-depleted growth conditions and that snow algal microbial communities can enhance mineral dissolution under these conditions.IMPORTANCE Fe, a key micronutrient for photosynthetic growth, is necessary to support the formation of high-density snow algal blooms. The laboratory experiments described herein allow for a systematic investigation of the interactions of snow algae, bacteria, and minerals and their ability to mobilize and uptake mineral-bound Fe. Results provide unequivocal and comprehensive evidence that mineral-bound Fe in Fe-bearing Fo90 was bioavailable to Chloromonas brevispina snow algae within an algal-bacterial coculture. This evidence includes (i) an observed increase in snow algal density and growth rate, (ii) decreased ratios of bacteria to algae in Fo90-containing cultures relative to those of cultures grown under similarly Fe-depleted conditions with no mineral-bound Fe present, and (iii) increased Fo90 dissolution rates in the presence of algal-bacterial cocultures relative to those of abiotic mineral controls. These results have important implications for the role of mineral dust in supplying micronutrients to the snow microbiome, which may help support dense snow algal blooms capable of lowering snow albedo and increasing snow melt rates on regional, and possibly global, scales.
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Iron status in the elderly: A review of recent evidence.
Wawer, AA, Jennings, A, Fairweather-Tait, SJ
Mechanisms of ageing and development. 2018;:55-73
Abstract
A comprehensive literature review of iron status in the elderly was undertaken in order to update a previous review (Fairweather-Tait et al, 2014); 138 summarised papers describe research on the magnitude of the problem, aetiology and age-related physiological changes that may affect iron status, novel strategies for assessing iron status with concurrent health conditions, hepcidin, lifestyle factors, iron supplements, iron status and health outcomes (bone mineral density, frailty, inflammatory bowel disease, kidney failure, cancer, cardiovascular, and neurodegenerative diseases). Each section of this review concludes with key points from the relevant papers. The overall findings were that disturbed iron metabolism plays a major role in a large number of conditions associated with old age. Correction of iron deficiency/overload may improve disease prognosis, but diagnosis of iron deficiency requires appropriate cut-offs for biomarkers of iron status in elderly men and women to be agreed. Iron deficiency (with or without anemia), anemia of inflammation, and anemia of chronic disease are all widespread in the elderly and, once identified, should be investigated further as they are often indicative of underlying disease. Management options should be reviewed and updated, and novel therapies, which show potential for treating anemia of inflammation or chronic disease, should be considered.
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Peripheral iron levels in children with attention-deficit hyperactivity disorder: a systematic review and meta-analysis.
Tseng, PT, Cheng, YS, Yen, CF, Chen, YW, Stubbs, B, Whiteley, P, Carvalho, AF, Li, DJ, Chen, TY, Yang, WC, et al
Scientific reports. 2018;(1):788
Abstract
There is growing recognition that the risk of attention-deficit hyperactivity disorder (ADHD) in children may be influenced by micronutrient deficiencies, including iron. We conducted this meta-analysis to examine the association between ADHD and iron levels/iron deficiency (ID). We searched for the databases of the PubMed, ScienceDirect, Cochrane CENTRAL, and ClinicalTrials.gov up to August 9th, 2017. Primary outcomes were differences in peripheral iron levels in children with ADHD versus healthy controls (HCs) and the severity of ADHD symptoms in children with/without ID (Hedges' g) and the pooled adjusted odds ratio (OR) of the association between ADHD and ID. Overall, seventeen articles met the inclusion criteria. Peripheral serum ferritin levels were significantly lower in ADHD children (children with ADHD = 1560, HCs = 4691, Hedges' g = -0.246, p = 0.013), but no significant difference in serum iron or transferrin levels. In addition, the severity of ADHD was significantly higher in the children with ID than those without ID (with ID = 79, without ID = 76, Hedges' g = 0.888, p = 0.002), and there was a significant association between ADHD and ID (OR = 1.636, p = 0.031). Our results suggest that ADHD is associated with lower serum ferritin levels and ID. Future longitudinal studies are required to confirm these associations and to elucidate potential mechanisms.
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Comparison of serum concentration of Ca, P, Mg, and Fe between hemifacial spasm patients and healthy controls; prospective randomized controlled study.
Ulusoy, EK, Ulusoy, DM, Kilic, S
Nigerian journal of clinical practice. 2018;(11):1537-1541
Abstract
PURPOSE In this study, we aimed to measure the serum vitamin D level in hemifacial spasmic (HFS) patients and show the role of HFS in the pathogenesis and place in etiology. MATERIALS AND METHODS This study included 43 prospective newly diagnosed HFS patients and 43 healthy volunteers in the neurology clinic. The serum (Ca, P, Mg, Fe) concentration of 4 essential elements was measured with a biochemical device. The groups were correlated in terms of four essential element concentrations. The severity of the disease was measured using Lee's Quality of Life Scale and correlated with the concentration of four trace elements. The results were compared using the independent t-test and Mann-Whitney U-test. RESULTS Concentration of serum Ca, P, and Mg in the HFS patients was found to be lower in the control group which was statistically significant (P < 0.05). There was no statistically difference between the groups in terms of Fe concentration (P > 0.05). There was no significant correlation between trace element concentration and severity of illness and daily life quality in the patient group. CONCLUSION These results show us the role of HFS in the pathogenesis of these four trace elements and the importance of its location in etiology. We think that changes in the concentration of trace elements in HFS can lead to demyelinization, which may lead to spasm.
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Impact of iron deficiency on exercise capacity and outcome in heart failure with reduced, mid-range and preserved ejection fraction.
Martens, P, Nijst, P, Verbrugge, FH, Smeets, K, Dupont, M, Mullens, W
Acta cardiologica. 2018;(2):115-123
Abstract
BACKGROUND Little information is available about the prevalence and impact on exercise capacity and outcome of iron deficiency in heart failure with mid-range (HFmrEF) and preserved (HFpEF) ejection fraction in comparison to heart failure with reduced ejection-fraction (HFrEF). Furthermore, no data is available about the progression of ID in patients without baseline anaemia. METHODS We evaluated baseline iron and haemoglobin-status in a single-centre, prospective heart failure database. Baseline functional status, VO2max, echocardiography and clinical-outcome (all-cause mortality and heart failure admissions) were evaluated. ID, anaemia, HFrEF, HFmrEF and HFpEF were defined according to established criteria. RESULTS A total of 1197 patients (71% male) were evaluated (HFrEF, n = 897; HFmrEF, n = 229; HFpEF, n = 72). The overall prevalence of ID was 53% (50% in HFrEF; 61% in HFmrEF; 64% in HFpEF) and 36% for anaemia. ID was associated with a lower VO2max in patients with HFrEF, HFmrEF and HFpEF (p < .001 in all). Iron status more closely related to a poor VO2max than anaemia status (p < .001). Furthermore, poor clinical-outcome was more strongly associated with iron status than anaemia status. Exposing eight patients without anaemia to iron deficiency for 39 months resulted in one patient developing new-onset anaemia (defined as progression of ID). Patients with progression of ID exhibited a significant higher risk of heart failure hospitalisation and all-cause mortality (HR = 1.4; CI = 1.01-1.94; p = .046) than patients without progression. CONCLUSIONS Iron deficiency is common in patients with HFrEF, HFmrEF and HFpEF, and negatively affects VO2max and clinical-outcome. Progression of iron deficiency parallels an increased risk for worsening of heart failure.
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Acidithiobacillus ferrooxidans and its potential application.
Zhang, S, Yan, L, Xing, W, Chen, P, Zhang, Y, Wang, W
Extremophiles : life under extreme conditions. 2018;(4):563-579
Abstract
The widely distributed Acidithiobacillus ferrooxidans (A. ferrooxidans) lives in extremely acidic conditions by fixing CO2 and nitrogen, and by obtaining energy from Fe2+ oxidation with either downhill or uphill electron transfer pathway and from reduced sulfur oxidation. A. ferrooxidans exists as different genomovars and its genome size is 2.89-4.18 Mb. The chemotactic movement of A. ferrooxidans is regulated by quorum sensing. A. ferrooxidans shows weak magnetotaxis due to formation of 15-70 nm magnetite magnetosomes with surface functional groups. The room- and low-temperature magnetic features of A. ferrooxidans are different from other magnetotactic bacteria. A. ferrooxidans has potential for removing sulfur from solids and gases, metals recycling from metal-bearing ores, electric wastes and sludge, biochemical production synthesizing, and metal workpiece machining.
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Fe(II) formation after interaction of the amyloid β-peptide with iron-storage protein ferritin.
Balejcikova, L, Siposova, K, Kopcansky, P, Safarik, I
Journal of biological physics. 2018;(3):237-243
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Abstract
The interaction of amyloid β-peptide (Aβ) with the iron-storage protein ferritin was studied in vitro. We have shown that Aβ during fibril formation process is able to reduce Fe(III) from the ferritin core (ferrihydrite) to Fe(II). The Aβ-mediated Fe(III) reduction yielded a two-times-higher concentration of free Fe(II) than the spontaneous formation of Fe(II) by the ferritin itself. We suggest that Aβ can also act as a ferritin-specific metallochaperone-like molecule capturing Fe(III) from the ferritin ferrihydrite core. Our observation may partially explain the formation of Fe(II)-containing minerals in human brains suffering by neurodegenerative diseases.
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Absorption Mechanisms of Iron, Copper, and Zinc: An Overview.
Nishito, Y, Kambe, T
Journal of nutritional science and vitaminology. 2018;(1):1-7
Abstract
Essential trace elements play pivotal roles in numerous structural and catalytic functions of proteins. Adequate intake of essential trace elements from the daily diet is indispensable to the maintenance of health, and their deficiency leads to a variety of conditions. However, excessive amounts of these trace elements may be highly toxic, and in some cases, may cause damage by the production of harmful reactive oxygen species. Homeostatic dysregulation of their metabolism increases the risk of developing diseases. Specific transport proteins that facilitate influx or efflux of trace elements play key roles in maintaining the homeostasis. Recent elucidation of their crucial functions significantly facilitated our understanding of the molecular mechanisms of iron (Fe), copper (Cu), and zinc (Zn) absorption in the small intestine. This paper summarizes their absorption mechanisms, with a focus on indispensable functions of the molecules involved in it, and briefly discusses the mechanisms of homeostatic control of each element at the cellular and systemic levels.