Biomarkers of Nutrition for Development (BOND)—Iron Review

This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health. The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation

Normal and Premature Rupture of Fetal Membranes at Term Delivery Differ in Regional Chemotactic Activity and Related Chemokine/Cytokine Production

A gradient of immunological mediators exists in the fetal membranes from the periplacental zone (PZ) to the rupture zone (RZ) at term delivery (rupture of fetal membranes [ROM]). However, it is unknown if this gradient is different in premature rupture of these tissues (premature rupture of fetal membranes [PROM]). We therefore analyzed leukocyte chemotactic activity and chemokine/cytokine production in fetal membrane zones in ROM and PROM. In ROM, leukocyte chemotactic activity increased from the PZ to the RZ; however, this did not occur in PROM. This was due to consistently elevated leukocyte chemotactic activity in PROM compared to ROM tissues. In the RZ, ROM was characterized by increased T-cell attraction and high levels of chemokine (C-X-C motif) ligand 8 (CXCL-8)/interleukin 8, and PROM by increased granulocyte attraction and high levels of granulocyte-macrophage colony-stimulating factor and CXCL-10/interferon gamma-induced protein 10. We conclude that normal and premature rupture of fetal membranes differ in regional chemotactic activity and related chemokine/cytokine production, which may represent evidence for differential mechanisms of rupture at term delivery.Nardhy Gomez-Lopez, Susana Hernandez-Santiago, Andrew P. Lobb, David M. Olson, and Felipe Vadillo-Orteg

A multilevel assessment of sediment bioremediation with bioturbating macrofauna

Estuaries and coastal intertidal environments supply important ecosystem services and resources. Within these systems, sediments play a crucial role in processing organic inputs and providing nutrients for local food webs. Benthic macrofauna and sediment microbial communities participate actively in these processes and can interact to influence overall ecosystem function. Through different bioturbation processes, macrofauna can affect biogeochemical cycling in sediments and influence microbial communities. However, anthropogenic derived eutrophication has increased globally in recent years and has been found to negatively impact these systems. Excess inputs of anthropogenic contaminants can disrupt key sediment processes involving macrofauna and microbial communities. Current options for sediment remediation are costly and may result in further impacts on communities. An alternative method for sediment bioremediation involves the application of macrofaunal bioturbators to stimulate microbial processes including contaminant removal. However, to confidently apply such an alternative requires clarity on the effect of macrofauna on contaminants, the contaminant concentrations at which macrofauna will actively affect the sediments, the potential effects of bioturbators on microbial communities, and whether these applications can be applied in situ at large scales. Here I used a systematic review and meta-analysis to analyse current knowledge on the effect of bioturbating macrofauna on contaminants and quantify how this interaction changes depending on relevant biotic and abiotic variables. Secondly, I used an experimental approach with sediment mesocosms to further explore the contaminant thresholds for effective remediation by macrofauna bioturbation and interactions with microbial communities in highly enriched sediments. Finally, a large-scale field experiment was done to explore the influence in situ nitrogen enrichment on microbial communities in the sediment and within macrofauna burrows under variable environmental contexts. The combined results here demonstrate that the effect of macrofauna bioturbation on stimulating bacterial communities in organically enriched sediments is highly taxa driven and additional factors such as macrofauna intraspecific variations in body size, temperature, animal density, magnitude of contamination and site specific organic matter content need to be considered for potential bioremediation and coastal management plans