Search

The use of road deicing salts in regions that experience cold winters is increasing the salinity of freshwater ecosystems, which threatens freshwater resources. Yet, the impacts of environmentally relevant road salt concentrations on freshwater organisms are not well understood, particularly in stream ecosystems where salinization is most severe. We tested the impacts of deicing salts—sodium chloride (NaCl), magnesium chloride (MgCl 2 ), and calcium chloride (CaCl 2 )—on the growth and development of newly hatched rainbow trout ( Oncorhynchus mykiss ). We exposed rainbow trout to a wide range of environmentally relevant chloride concentrations (25, 230, 860, 1500, and 3000 mg Cl − L −1 ) over an ecologically relevant time period (25 d). We found that the deicing salts studied had distinct effects. MgCl 2 did not affect rainbow trout growth at any concentration. NaCl had no effects at the lowest three concentrations, but rainbow trout length was reduced by 9% and mass by 27% at 3000 mg Cl − L −1 . CaCl 2 affected rainbow trout growth at 860 mg Cl − L −1 (5% reduced length; 16% reduced mass) and these effects became larger at higher concentrations (11% reduced length; 31% reduced mass). None of the deicing salts affected rainbow trout development. At sub-lethal and environmentally relevant concentrations, our results do not support the paradigm that MgCl 2 is the most toxic deicing salt to fish, perhaps due to hydration effects on the Mg 2+ cation. Our results do suggest different pathways for lethal and sub-lethal effects of road salts. Scaled to the population level, the reduced growth caused by NaCl and CaCl 2 at critical early-life stages has the potential to negatively affect salmonid recruitment and population dynamics. Our findings have implications for environmental policy and management strategies that aim to reduce the impacts of salinization on freshwater organisms. [ABSTRACT FROM AUTHOR]

We studied the avoidance behaviour of the earthworm Eisenia fetida towards Cd, Cu, and Zn, trace elements (TEs) tested as chloride, nitrate and sulphate salts. Sub adults were exposed individually using dual-cell chambers at 20 + 2 °C in the dark. Recordings were realised at different dates from 2 h to 32 h. We used filter paper and extruded water agar gel as exposure media to evaluate the contribution of the dermal and the digestive exposure routes on the avoidance reactions. Exposures to Cu or Cd (10 mg metal ion L −1 ) resulted in highly significant avoidance reactions through the exposure duration. Worms avoided Zn poorly and reactions towards Zn salts varied along the exposure. Worm sensitivity towards TEs differed between salts and this could result from differential toxicity or accessibility of these TE salts to earthworms. The anion in itself was not the determinant of the avoidance reactions since exposures to similar concentrations of these anions using calcium salts did not result in significant avoidance worm behaviour. Avoidance responses towards TEs were higher in the case of water agar exposures than in filter paper exposures. Thus, dermal contacts with TE solutions would elicit worm avoidance but signals from receptors located inside the digestive tract could reinforce this behaviour. The use of extruded water agar gels as the substrate allows checking the real sensitivity of earthworm species towards TEs since the TE concentrations leading to significant avoidance reactions were below those reported in the literature when using TE-spiked soils. [ABSTRACT FROM AUTHOR]

Abstract: Objective: Recent data would suggest pre-menopausal insulin resistant women are more prone to diastolic dysfunction than men, yet it is unclear why. We and others have reported that transgenic (mRen2)27 (Ren2) rats overexpressing the murine renin transgene are insulin resistant due to oxidative stress in insulin sensitive tissues. As increased salt intake promotes inflammation and oxidative stress, we hypothesized that excess dietary salt would promote diastolic dysfunction in transgenic females under conditions of excess tissue Ang II and circulating aldosterone levels. Materials/methods: For this purpose we evaluated cardiac function in young female Ren2 rats or age-matched Sprague–Dawley (SD) littermates exposed to a high (4%) salt or normal rat chow intake for three weeks. Results: Compared to SD littermates, at 10weeks of age, female Ren2 rats fed normal chow showed elevations in left ventricular (LV) systolic pressures, LV and cardiomyocyte hypertrophy, and displayed reductions in LV initial filling rate accompanied by increases in 3-nitrotyrosine content as a marker of oxidant stress. Following 3weeks of a salt diet, female Ren2 rats exhibited no further changes in LV systolic pressure, insulin resistance, or markers of hypertrophy but exaggerated increases in type 1 collagen, 3-nitrotryosine content, and diastolic dysfunction. These findings occurred in parallel with ultrastructural findings of pericapillary fibrosis, increased LV remodeling, and mitochondrial biogenesis. Conclusion: These data suggest that a diet high in salt in hypertensive female Ren2 rats promotes greater oxidative stress, maladaptive LV remodeling, fibrosis, and associated diastolic dysfunction without further changes in LV systolic pressure or hypertrophy. [Copyright &y& Elsevier]

Radiation accelerates ageing, producing telomere shortening, metabolic ageing, cell apoptosis, immunological decline, mitochondrial damage, free radical damage and oxidative stress. Salts of iodine, strontium and caesium may reverse ageing induced by nuclear radiation. The American Thyroid Association (ATA) has established that potassium iodide (KI) needs to be accessible to those within 50 miles of nuclear reactors. Despite ATA recommendations, if you distribute KI at the time of explosion, it may not be effective; thus, it is a preventive measure, not a tertiary treatment. KI treatment is most successful when used prior to radioactive iodine exposure. Weekly supplementation of KI reduces hypothyroidism and thyroid nodules; strontium carbonate (SrCO3) reduces osteopenia and inadequate bone development; and caesium chloride (CsCl) reduces brain cell apoptosis and anxiety. Low doses of radiation may result in hormesis and improved health. A radiation cleanup plan with further investigation could be implemented as a preventive measure. [ABSTRACT FROM AUTHOR]

Abstract: Perennial ryegrass (Lolium perenne L.) is a popular turfgrass species. To understand the molecular mechanisms of salinity tolerance, a suppression subtractive cDNA library was constructed for a salinity-tolerant ryegrass accession, with NaCl-treated (255mM) plants as the tester. Differentially expressed cDNA fragments were cloned and screened. BLAST search revealed that 268 clones exhibited significant homologies to known genes. These genes could be categorized into 11 different functional groups, including metabolism, energy transfer, detoxification, compatible solute, cellular transport, transcription, signal transduction, etc. The salinity-regulated expression of selected genes was confirmed by RT-PCR analysis. The results suggested that these putatively salinity up-regulated genes may play a vital role in the salinity tolerance of perennial ryegrass. They can be used as candidate genes for creating stress-tolerant grasses and for understanding molecular mechanisms of plant adaptation to salinity stress. [Copyright &y& Elsevier]

Abstract: Gill is the primary osmoregulatory organ for euryhaline fish to acclimate salinity change. The effect of salinity on gill proteome in ayu, Plecoglossus altivelis, was investigated by two-dimensional gel electrophoresis (2-DE) and matrix assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS/MS). Eight of eighteen altered proteins were successfully identified. They are involved in osmoregulation, cytoskeleton, energy metabolism, and stress response. Our results showed that vinculin, echinoderm microtubule-associated protein like protein 1, pyruvate kinase, betaine–homocysteine methyltransferase (BHMT), transaldolase, glyceraldehyde 3-phosphate dehydrogenase, and heat shock protein 70 (HSP70) were down-regulated, whereas cofilin was up-regulated when ayu transferred from fresh water (FW) to brackish water (BW). Partial cDNA sequences of BHMT, HSP70, Na+/K+ ATPase (NKA) α-subunit and 18S rRNA genes were subsequently determined and used for 2-DE data verification by real-time PCR. Gill BHMT and HSP70 mRNAs decreased significantly in BW-transferred ayu, while NKA α-subunit mRNA had no significant change. It was suggested that cell volume-regulatory response, especially the protection by the BHMT/betaine system might play an important role in ayu acclimation to salinity change. [ABSTRACT FROM AUTHOR]

Abstract: As the life cycle of ayu spans river, brackish and seawater environments, it would be a suitable fish model for studying the responses to salinity changes in aquatic animals. We investigated the effect of salinity on trunk kidney proteome in ayu (Plecoglossus altivelis) using two-dimensional gel electrophoresis and mass spectrometry. The proteins involved in the process of energy metabolism, biosynthesis, DNA methylation and cell differentiation were mainly affected, and 10 significantly changed proteins were identified. Our result showed that isocitrate dehydrogenase (ICD), pyruvate dehydrogenase (E1), O-glycosyl hydrolase, mitochondrial precursor of ATP synthase subunit beta, mitochondrial ferrtin (MtF), retinol binding protein (RBP) were down-regulated, whereas aldehyde dehydrogenase, cytokeratin 1, S-adenosylhomocysteine hydrolase, Cys-Met metabolism PLP-dependent enzyme were up-regulated when ayu transferred from freshwater to brackish water. Partial coding sequences of E1, ICD, MtF and RBP genes were determined, and the effects of salinity on their mRNA expression in ayu trunk kidney were tested by real-time PCR subsequently. Their possible direct or indirect roles in the adaptation of ayu to salinity are discussed. [Copyright &y& Elsevier]

In this work we aimed to test the antibacterial effect of many copper and bismuth powders (salts) on Gram positive and Gram negative bacterial species. Eight samples of [(xB2O3(1-x)Bi2O3]10%CuO and another eight of [(xB2O3(1-x)Bi2O3] with various granulations (0.07≤x≤0.8), were tested in laboratory conditions on four bacterial strains (Staphylococcus aureus, Bacillus cereus Pseudomonas aeruginosa and Escherichia coli), determining minimum inhibitory concentration (MIC) using diffusimethrical method. It was proved that both copper and bismuth salts had inhibitory effect on the tested bacterial species. Gram positive bacteria (Staphylococcus aureus and Bacillus cereus) were sensitive to the activity of cooper salts combined with bismuth. Gram negative bacteria (Pseudomonas aeruginosa and Escherichia coli) were also sensitive to the activity of the two powder categories but the inhibitory effect was more reduced comparatively to the effect obtained for Gram positive strains. A reduced dimension of the powders increases the inhibitory effect. [ABSTRACT FROM AUTHOR]