Zinc and infant nutrition Ackland, M. Leigh; Michalczyk, Agnes A.
Archives of biochemistry and biophysics,
12/2016, Letnik:
611
Journal Article
Recenzirano
Zinc is essential for a wide variety of cellular processes in all cells. It is a critical dietary nutrient, particularly in the early stages of life. In the early neonatal period, adequate sources of ...zinc can be obtained from breast milk. In rare circumstances, the mammary gland produces zinc deficient milk that is potentially lethal for exclusively breast-fed infants. This can be overcome by zinc supplementation to the infant. Alterations to key zinc transporters provide insights into the mechanisms of cellular zinc homeostasis. The bioavailability of zinc in food depends on the presence of constituents that may complex zinc. In many countries, zinc deficiency is a major health issue due to poor nourishment. Young children are particularly affected. Zinc deficiency can impair immune function and contributes to the global burden of infectious diseases including diarrhoea, pneumonia and malaria. Furthermore, zinc deficiency may extend its influence across generations by inducing epigenetic effects that alter the expression of genes. This review discusses the significance of adequate zinc nutrition in infants, factors that influence zinc nutrition, the consequences of zinc deficiency, including its contribution to the global burden of disease, and addresses some of the knowledge gaps in zinc biology.
•Zinc is critical for infant growth and development.•Zinc nutrition depends on zinc bioavailability.•Zinc deficiency is a major global health issue that affects young children.•Alterations in zinc transporters can cause zinc-deficient breast milk.
Abstract Epithelial ovarian cancer (EOC) has a relatively high mortality rate (∼ 55%). One of the presiding causes is that the current chemotherapeutic regimes are unable to achieve sustained ...remission, despite frequently producing a positive response at first treatment. One of the reasons that EOC is difficult to treat is that the mechanism of dissemination is unusual. EOC dissemination characteristically involves local invasion of pelvic and abdominal organs. Unlike many epithelial cancers, initial dissemination rarely requires the vasculature, although the vasculature is often implicated in the advanced stages of disease. Recently, it has become apparent that aggregates of malignant cells (spheroids) contained within malignant ascites represent a significant impediment to efficacious treatment of late stage EOC. In vivo , spheroids are present in the malignant ascites of EOC patients, while in vitro cultured spheroids are capable of tumorgenesis in vivo and display a reduced response to chemotherapeutic drugs when compared to monolayers. A major problem associated with the current generation of chemotherapy agents is that they do not address the anchorage- and vascular-independent growth conditions associated with a 3-dimensional structure that has formed and/or grown in suspension. Thus, spheroid formation may represent a key component of platinum/taxane-sensitive recurrence. If this is correct, a better understanding of spheroid biology may contribute to the identification of new treatment opportunities for the sustained treatment of metastatic EOC. This review article outlines the key biological features of spheroids, specifically discussing their role in EOC dissemination and chemo-response as well as providing insights into spheroid functionality.
Field trials contribute practical information towards the development of phytoremediation strategies that cannot be provided by laboratory tests. We conducted field experiments utilizing the Cd ...hyperaccumulator plant
Solanum nigrum L., on farmland contaminated with 1.91 mg kg
−1 Cd in the soil. Our study showed that
S. nigrum has a relatively high biomass. Planting density had a significant effect on the plant biomass and thus on overall Cd accumulation. For double harvesting, an optimal cutting position influenced the amount of Cd extracted from soils. Double cropping was found to significantly increase the amount of Cd extracted by
S. nigrum. Fertilizing had no significant effect on plant biomass or on the Cd remediation of the soil over the short-term period. Our study indicates that
S. nigrum can accumulate Cd from soils where the concentrations are relatively low, and thus has application for use in decontamination of slightly to moderately Cd-contaminated soil.
►
S. nigrum L. is an effective phytoremediation plant for Cd-polluted soils. ►Agronomy practices that increase harvested biomass improve bioremediation efficiency. ►Double cropping of
S. nigrum L. is an effective phytoremediation strategy. ►Field experiments are necessary to effectively assess phytoremediation techniques.
Agronomic practice for the phytoremediation potential of
Solanum nigrum L. for Cd uptake was demonstrated in field contaminated soils.
Microbial Nanowires: An Electrifying Tale Sure, Sandeep K; Ackland, Leigh M; Torriero, Angel A ...
Microbiology (Society for General Microbiology),
12/2016, Letnik:
162, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Electromicrobiology has gained momentum in the last ten years with advances in microbial fuel cells and the discovery of microbial nanowires (MNWs). The list of MNWs producing microorganisms is ...growing and providing intriguing insights into the presence of such microorganisms in diverse environments and the potential roles MNWs can perform. This review discusses the MNWs produced by different microorganisms, including their structure, composition and role in electron transfer through MNWs. Two hypotheses, metallic-like conductivity and an electron hopping model, have been proposed for electron transfer and we present a current understanding of both these hypotheses. MNWs are not only poised to change the way we see microorganisms but may also impact the fields of bioenergy, biogeochemistry and bioremediation, hence their potential applications in these fields are highlighted here.
Neuroendocrine neoplasms (NENs) are relatively rare neoplasms occurring predominantly in the gastrointestinal tract and pancreas. Their heterogeneity poses challenges for diagnosis and treatment. ...There is a paucity of markers for characterisation of NEN tumours. For routine diagnosis, immunohistochemistry of the NEN-specific markers CgA and synaptophysin and the proliferation marker Ki-67 are used. These parameters, however, are qualitative and lack the capacity to fully define the tumour phenotype. Molecules of epithelial–mesenchymal transition (EMT) are potential candidates for improved tumour characterisation. Using qRT-PCR, we measured mRNA levels of 27 tumour markers, including 25 EMT-associated markers, in tumour tissue and matched non-tumour tissues for 13 patients with pancreatic NENs. Tissue from patients with three different grades of tumour had distinctly different mRNA profiles. Of the 25 EMT-associated markers analysed, 17 were higher in G3 tissue relative to matched non-tumour tissue, including CD14, CD24, CD31, CD44, CD45, CD56, CK6, CK7, CK13, CK20, NSE, CDX2, CgA, DAXX, PCNA, laminin and Ki-67. The differences in levels of seven EMT-associated markers, Ki-67, DAXX, CD24, CD44, vimentin, laminin and PDX1 plus CgA and NSE (neuroendocrine markers) enabled a distinct molecular signature for each tumour grade to be generated. EMT molecules differentially expressed in three tumour grades have potential for use in tumour stratification and prognostication and as therapeutic targets for treatment of neuroendocrine cancers, following validation with additional samples.
Microalgae are important renewable feedstock to produce biodiesel and high‐value chemicals. Different wavelengths of light influence the growth and metabolic activities of algae. Recent research has ...identified the light‐sensing proteins called photoreceptors that respond to blue or red light. Structural elucidations of algal photoreceptors have gained momentum over recent years. These include channelrhodopsins, PHOT proteins, animal‐like cryptochromes, and blue‐light sensors utilizing flavin‐adenine dinucleotide proteins. Pulsing light has also been investigated as a means to optimize energy inputs into bioreactors. This study summarizes the current structural and functional basis of photoreceptor modulation to optimize the growth, production of carotenoids and other high‐value metabolites from microalgae. The review also encompasses novel photobioreactor designs that implement different light regimes including light wavelengths and time to optimize algal growth and desired metabolite profiles for high‐value products.
Microalgae consist of a plethora of photoreceptors receptive to different wavelengths of light. Shankar et al explained the importance of combining flashing light technology to map to the timescales of the photoreceptors which will lead to higher growth and metabolite productivity. These photoreceptors have been found to have an impact on the metabolites (especially carotenoids) at the molecular level. Novel photobioreactor designs with flashing light would help achieve this leading to improved microalgal strains.
Intracellular zinc homeostasis is strictly regulated by zinc binding proteins and zinc transporters. In the present study, we quantified in a first global view the expression of all characterized ...human zinc exporters (hZnT‐1‐9) in different leukocyte subsets in response to zinc supplementation and depletion and analyzed their influence on alterations in the intracellular zinc concentration. We found that hZnT‐1 is the most regulated zinc exporter. Furthermore, we discovered that hZnT‐4 is localized in the plasma membrane similar to hZnT‐1. hZnT‐4 is most highly expressed in Molt‐4, up‐regulated after treatment with PHA and is responsible for the measured decrease of intracellular zinc content after high zinc exposure. In addition, we found that hZnT‐5, hZnT‐6, and hZnT‐7 in Raji as well as hZnT‐6 and hZnT‐7 in THP‐1 are up‐regulated in response to cellular zinc depletion. Those zinc exporters are all localized in the Golgi network, and this type of regulation explains the observed zinc increase in both cell types after up‐regulation of their expression during zinc deficiency and, subsequently, high zinc exposure. Furthermore, we detected, for the first time, the expression of hZnT‐8 in peripheral blood lymphocytes, which varied strongly between individuals. While hZnT‐2 was not detectable, hZnT‐3 and hZnT‐9 were expressed at low levels. Further on, the amount of expression was higher in primary cells than in cell lines. These data provide insight into the regulation of intracellular zinc homeostasis in cells of the immune system and may explain the variable effects of zinc deficiency on different leukocyte subsets.
Cr(VI) tolerance in Aspergillus flavus, strain SFL, isolated from tannery effluent was measured and compared with a reference strain of A. flavus, A1120. On solid medium, SFL had a high level of ...Cr(VI) tolerance (1,600 mg/L), which was 16 times that of A1120 and greater than most previously analyzed fungal strains. When in 100 mg/L of Cr(VI), SFL completely depleted Cr(VI) within 72 h while A1120 depleted 85% of Cr(VI). SFL was more effective in reducing extracellular Cr(VI) than A1120. While A1120 showed greater biosorption of Cr(VI) than SFL, intracellular accumulation was approximately 50% greater in SFL and was more energy‐dependent than A1120. Cr(VI) modified the external surface of the hyphae. Cr speciation detected the presence of only Cr(III), corresponding to Cr(OH)3, which precipitated on the hyphal surface. Cr(VI) bound to the functional groups carboxyl, amine, and hydroxyl in both SFL and A1120. Transmission electron microscopy energy‐dispersive X‐ray detected Cr on the fungal wall and within membrane‐bound organelles of the cytoplasm. In conclusion, the greater tolerance of SFL to Cr(VI) relative to A1120 is due to more effective energy‐dependant uptake of Cr(VI) into the cell and increased capacity of SFL to store Cr in intracellular vacuoles compared with A1120.
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Molecular interactions between 4-OH-cinnamate and cetrimonium in solution result in improved adsorption of the cinnamate on mild steel, developing a protective mechanism against the ...diffusion of corrosive chloride to the oxide surface. Fundamental understanding of this mechanism should allow new design routes for the development of eco-friendly corrosion inhibitors.
Via classic molecular dynamics, simulations were carried out for cetrimonium and 4-OH-cinnamate in aqueous solutions at different ionic strengths and the results were validated with experimental SAXS data. Self-aggregation of cetrimonium 4-OH-cinnamate on a hydrated hematite surface was then simulated and results were compared with cryo-TEM imaging for the same compound. Finally, the effect of the adsorbed aggregates on chloride diffusion to the oxide surface was modelled.
Simulations showed the encapsulation of 4-OH-cinnamate into cetrimonium micelles, consistent with experiments. The newly formed micelles adsorb onto a hydrated iron oxide surface by forming hydrogen bonds between their carboxylate outer-shell groups and the surface hydroxyls. As the adsorbate concentrations increase, there is a morphological transition from spherical to wormlike adsorbed aggregates. The wormlike structure can block chloride ions, demonstrating a synergistic inhibitory mechanism between both cetrimonium and 4-OH-cinnamate. Encapsulation and delivery of active compounds to certain targets, such as carcinogenic tumors, have been well studied in biochemistry research, we demonstrate that the same mechanism can be applied to the design of efficient corrosion inhibitors, optimizing their delivery to the metal surface.
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