443 research outputs found
Brief communication:getting Greenland’s glaciers right – a new data set of all official Greenlandic glacier names
Place names in Greenland can be difficult to get right, as they are a mix of
Greenlandic, Danish, and other foreign languages. In addition, orthographies
have changed over time. With this new data set, we give the researcher
working with Greenlandic glaciers the proper tool to find the correct name
for glaciers and ice caps in Greenland and to locate glaciers described in
the historic literature with the old Greenlandic orthography. The data set
contains information on the names of 733 glaciers, 285 originating from the
Greenland Ice Sheet (GrIS) and 448 from local glaciers and ice caps (LGICs)
Body mass index trajectories in early childhood in relation to cardiometabolic risk profile and body composition at 5 years of age
BACKGROUND: Both impaired and accelerated postnatal growth have been associated with adult risks of obesity and cardiometabolic diseases, like type 2 diabetes and cardiovascular disease. However, the timing of the onset of cardiometabolic changes and the specific growth trajectories linking early growth with later disease risks are not well understood. OBJECTIVES: The aim of this study was to identify distinct trajectories of BMI growth from 0 to 5 y and examine their associations with body composition and markers of cardiometabolic risk at age 5 y. METHODS: In a prospective birth cohort study of 453 healthy and term Ethiopian children with BMIs assessed a median of 9 times during follow-up, we identified subgroups of distinct BMI trajectories in early childhood using latent class trajectory modeling. Associations of the identified growth trajectories with cardiometabolic markers and body composition at 5 y were analyzed using multiple linear regression analyses in 4 adjustment models for each outcome. RESULTS: We identified 4 heterogeneous BMI growth trajectories: stable low BMI (19.2%), normal BMI (48.8%), rapid catch-up to high BMI (17.9%), and slow catch-up to high BMI (14.1%). Compared with the normal BMI trajectory, children in the rapid catch-up to high BMI trajectory had higher triglycerides (TGs) (range of β-coefficients in Models 1-4: 19-21%), C-peptides (23-25%), fat masses (0.48-0.60 kg), and fat-free masses (0.50-0.77 kg) across the 4 adjustment models. Children in the stable low BMI trajectory had lower LDL cholesterol concentrations (0.14-0.17 mmol/L), HDL cholesterol concentrations (0.05-0.09 mmol/L), fat masses (0.60-0.64 kg), and fat-free masses (0.35-0.49 kg), but higher TGs (11-13%). CONCLUSIONS: The development of obesity and cardiometabolic risks may be established already in early childhood; thus, our data provide a further basis for timely interventions targeted at young children from low-income countries with unfavorable growth patterns. The birth cohort was registered at ISRCTN as ISRCTN46718296
TDP-43 loss of function inhibits endosomal trafficking and alters trophic signaling in neurons
Nuclear clearance of TDP-43 into cytoplasmic aggregates is a key driver of neurodegeneration in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), but the mechanisms are unclear. Here, we show that TDP-43 knockdown specifically reduces the number and motility of RAB11-positive recycling endosomes in dendrites, while TDP-43 overexpression has the opposite effect. This is associated with delayed transferrin recycling in TDP-43-knockdown neurons and decreased 2-transferrin levels in patient CSF. Whole proteome quantification identified the upregulation of the ESCRT component VPS4B upon TDP-43 knockdown in neurons. Luciferase reporter assays and chromatin immunoprecipitation suggest that TDP-43 represses VPS4B transcription. Preventing VPS4B upregulation or expression of its functional antagonist ALIX restores trafficking of recycling endosomes. Proteomic analysis revealed the broad reduction in surface expression of key receptors upon TDP-43 knockdown, including ErbB4, the neuregulin 1 receptor. TDP-43 knockdown delays the surface delivery of ErbB4. ErbB4 overexpression, but not neuregulin 1 stimulation, prevents dendrite loss upon TDP-43 knockdown. Thus, impaired recycling of ErbB4 and other receptors to the cell surface may contribute to TDP-43-induced neurodegeneration by blocking trophic signaling
Children with moderate acute malnutrition have inflammation not explained by maternal reports of illness and clinical symptoms: a cross-sectional study in Burkina Faso
Background
Morbidity plays an important role in the development of and recovery from malnutrition. Morbidity in children with moderate acute malnutrition (MAM) has not been described in detail and it is unclear how morbidity compares to serum levels of acute phase proteins (APPs) which indicate systemic inflammation and which can impede response to therapeutic nutritional interventions. The objective of this study was to describe morbidity in children with MAM and to assess to what extent maternally reported and clinically diagnosed morbidity explain the variation in APPs.
Methods
A cross-sectional sub study was conducted as part of a nutrition intervention trial among 6–23 months old children with MAM residing in Burkina Faso. Morbidity data collection at baseline included 2 week maternal recalls and physical examinations. Multivariate ANCOVA models were used to explore the associations between morbidity and C-reactive protein (CRP) as well as α1-acid glycoprotein (AGP). These models were also used to determine to what extent morbidity explains variation in APPs.
Results
In the 2 weeks prior to the study inclusion visit, 38 % of children were ill according to mothers. Furthermore, 71.8 % of children had a symptom or infection identified during the physical examination and 24.2 and 66.4 % of children had elevated CRP and AGP, respectively. Among children without any identified symptom or illness at the inclusion visit, 10.7 and 46.5 % had elevated CRP and AGP, respectively. History of fever as well as nurse-documented fever, malaria, respiratory tract infections and skin infections were associated with higher levels of both APPs. History of cough and diarrhoea at the inclusion visit was associated with higher α1-acid glycoprotein only. Overall, morbidity data only explained a small amount of the variation in APP levels (adjusted R2 below 0.2 in all tested models).
Conclusion
Morbidity among children with MAM in this setting is common, but maternal reports and clinical examination explained only a small proportion of the variation in APPs, indicating a presence of subclinical inflammation. We recommend further research into the causes of this subclinical inflammation as it could affect nutritional status and success of MAM treatment.BioMed Central open acces
Associations of fat mass and fat-free mass accretion in infancy with body composition and cardiometabolic risk markers at 5 years: The Ethiopian iABC birth cohort study
BACKGROUND: Accelerated growth in early childhood is an established risk factor for later obesity and cardiometabolic disease, but the relative importance of fat mass (FM) and fat-free mass (FFM) accretion is not well understood. We aimed to study how FM and FFM at birth and their accretion during infancy were associated with body composition and cardiometabolic risk markers at 5 years. METHODS AND FINDINGS: Healthy children born at term were enrolled in the Infant Anthropometry and Body Composition (iABC) birth cohort between December 2008 and October 2012 at Jimma University Specialized Hospital in the city of Jimma, Ethiopia. FM and FFM were assessed using air displacement plethysmography a median of 6 times between birth and 6 months of age. In 507 children, we estimated individual FM and FFM at birth and their accretion over 0-3 and 3-6 months of age using linear-spline mixed-effects modelling. We analysed associations of FM and FFM at birth and their accretion in infancy with height, waist circumference, FM, FFM, and cardiometabolic risk markers at 5 years using multiple linear regression analysis. A total of 340 children were studied at the 5-year follow-up (mean age: 60.0 months; girls: 50.3%; mean wealth index: 45.5 out of 100; breastfeeding status at 4.5 to 6 months post-partum: 12.5% exclusive, 21.4% almost exclusive, 60.6% predominant, 5.5% partial/none). Higher FM accretion in infancy was associated with higher FM and waist circumference at 5 years. For instance, 100-g/month higher FM accretion in the periods 0-3 and 3-6 months was associated with 339 g (95% CI: 243-435 g, p < 0.001) and 367 g (95% CI: 250-484 g, p < 0.001) greater FM at 5 years, respectively. Higher FM at birth and FM accretion from 0 to 3 months were associated with higher FFM and cholesterol concentrations at 5 years. Associations for cholesterol were strongest for low-density lipoprotein (LDL)-cholesterol, and remained significant after adjusting for current FM. A 100-g higher FM at birth and 100-g/month higher FM accretion from 0 to 3 months were associated with 0.16 mmol/l (95% CI: 0.05-0.26 mmol/l, p = 0.005) and 0.06 mmol/l (95% CI: 0.01-0.12 mmol/l, p = 0.016) higher LDL-cholesterol at 5 years, respectively. Higher FFM at birth and FFM accretion in infancy were associated with higher FM, FFM, waist circumference, and height at 5 years. For instance, 100-g/month higher FFM accretion in the periods 0-3 and 3-6 months was associated with 1,002 g (95% CI: 815-1,189 g, p < 0.001) and 624 g (95% CI: 419-829 g, p < 0.001) greater FFM at 5 years, respectively. We found no associations of FM and FFM growth with any of the other studied cardiometabolic markers including glucose, HbA1c, insulin, C-peptide, HOMA-IR, triglycerides, and blood pressure. Non-attendance at the 5-year follow-up visit was the main limitation of this study, which may have introduced selection bias and limited the power of the regression analyses. CONCLUSIONS: FM accretion in early life was positively associated with markers of adiposity and lipid metabolism, but not with blood pressure and cardiometabolic markers related to glucose homeostasis. FFM accretion was primarily related to linear growth and FFM at 5 years
Expanding the Versatility of Phage Display II: Improved Affinity Selection of Folded Domains on Protein VII and IX of the Filamentous Phage
Background: Phage display is a leading technology for selection of binders with affinity for specific target molecules. Polypeptides are normally displayed as fusions to the major coat protein VIII (pVIII) or the minor coat protein III (pIII). Whereas pVIII display suffers from drawbacks such as heterogeneity in display levels and polypeptide fusion size limitations, toxicity and infection interference effects have been described for pIII display. Thus, display on other coat proteins such as pVII or pIX might be more attractive. Neither pVII nor pIX display have gained widespread use or been characterized in detail like pIII and pVIII display.
Methodology/Principal Findings: Here we present a side-by-side comparison of display on pIII with display on pVII and pIX. Polypeptides of interest (POIs) are fused to pVII or pIX. The N-terminal periplasmic signal sequence, which is required for phage integration of pIII and pVIII and that has been added to pVII and pIX in earlier studies, is omitted altogether. Although the POI display level on pIII is higher than on pVII and pIX, affinity selection with pVII and pIX display libraries is shown to be particularly efficient.
Conclusions/Significance: Display through pVII and/or pIX represent platforms with characteristics that differ from those of the pIII platform. We have explored this to increase the performance and expand the use of phage display. In the paper, we describe effective affinity selection of folded domains displayed on pVII or pIX. This makes both platforms more attractive alternatives to conventional pIII and pVIII display than they were before.
© 2011 Wälchli et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Preserved Morphology and Physiology of Excitatory Synapses in Profilin1-Deficient Mice
Profilins are important regulators of actin dynamics and have been implicated in activity-dependent morphological changes of dendritic spines and synaptic plasticity. Recently, defective presynaptic excitability and neurotransmitter release of glutamatergic synapses were described for profilin2-deficient mice. Both dendritic spine morphology and synaptic plasticity were fully preserved in these mutants, bringing forward the hypothesis that profilin1 is mainly involved in postsynaptic mechanisms, complementary to the presynaptic role of profilin2. To test the hypothesis and to elucidate the synaptic function of profilin1, we here specifically deleted profilin1 in neurons of the adult forebrain by using conditional knockout mice on a CaMKII-cre-expressing background. Analysis of Golgi-stained hippocampal pyramidal cells and electron micrographs from the CA1 stratum radiatum revealed normal synapse density, spine morphology, and synapse ultrastructure in the absence of profilin1. Moreover, electrophysiological recordings showed that basal synaptic transmission, presynaptic physiology, as well as postsynaptic plasticity were unchanged in profilin1 mutants. Hence, loss of profilin1 had no adverse effects on the morphology and function of excitatory synapses. Our data are in agreement with two different scenarios: i) profilins are not relevant for actin regulation in postsynaptic structures, activity-dependent morphological changes of dendritic spines, and synaptic plasticity or ii) profilin1 and profilin2 have overlapping functions particularly in the postsynaptic compartment. Future analysis of double mutant mice will ultimately unravel whether profilins are relevant for dendritic spine morphology and synaptic plasticity
Effectiveness of food supplements on fat-free tissue accretion in children with moderate acute malnutrition: a randomized 2x2x3 factorial trial in Burkina Faso
BACKGROUND:
Children with moderate acute malnutrition (MAM) are treated with lipid-based nutrient supplement (LNS) or corn-soy blend (CSB). We assessed the effectiveness of (a) matrix, i.e., LNS or CSB, (b) soy quality, i.e., soy isolate (SI) or dehulled soy (DS), and (c) percentage of total protein from dry skimmed milk, i.e., 0%, 20%, or 50%, in increasing fat-free tissue accretion.
METHODS AND FINDINGS:
Between September 9, 2013, and August 29, 2014, a randomised 2 × 2 × 3 factorial trial recruited 6- to 23-month-old children with MAM in Burkina Faso. The intervention comprised 12 weeks of food supplementation providing 500 kcal/day as LNS or CSB, each containing SI or DS, and 0%, 20%, or 50% of protein from milk. Fat-free mass (FFM) was assessed by deuterium dilution technique. By dividing FFM by length squared, the primary outcome was expressed independent of length as FFM index (FFMI) accretion over 12 weeks. Other outcomes comprised recovery rate and additional anthropometric measures. Of 1,609 children, 4 died, 61 were lost to follow-up, and 119 were transferred out due to supplementation being switched to non-experimental products. No children developed allergic reaction. At inclusion, 95% were breastfed, mean (SD) weight was 6.91 kg (0.93), with 83.5% (5.5) FFM. In the whole cohort, weight increased 0.90 kg (95% CI 0.88, 0.93; p 0.05). LNS compared to CSB resulted in 128 g (95% CI 67, 190; p < 0.01) greater weight gain if both contained SI, but there was no difference between LNS and CSB if both contained DS (mean difference 22 g; 95% CI −40, 84; p = 0.49) (interaction p = 0.017). Accordingly, SI compared to DS increased weight by 89 g (95% CI 27, 150; p = 0.005) when combined with LNS, but not when combined with CSB. A limitation of this and other food supplementation trials is that it is not possible to collect reliable data on individual adherence.
CONCLUSIONS:
Based on this study, children with MAM mainly gain fat-free tissue when rehabilitated. Nevertheless, LNS yields more fat-free tissue and higher recovery rates than CSB. Moreover, current LNSs with DS may be improved by shifting to SI. The role of milk relative to soy merits further research
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