Acid–base regulatory ability of the cephalopod (Sepia officinalis) in response to environmental hypercapnia

Acidification of ocean surface waters by anthropogenic carbon dioxide (CO₂) emissions is a currently developing scenario that warrants a broadening of research foci in the study of acid–base physiology. Recent studies working with environmentally relevant CO₂ levels, indicate that some echinoderms and molluscs reduce metabolic rates, soft tissue growth and calcification during hypercapnic exposure. In contrast to all prior invertebrate species studied so far, growth trials with the cuttlefish Sepia officinalis found no indication of reduced growth or calcification performance during long-term exposure to 0.6 kPa CO₂. It is hypothesized that the differing sensitivities to elevated seawater pCO₂ could be explained by taxa specific differences in acid–base regulatory capacity. In this study, we examined the acid–base regulatory ability of S. officinalis in vivo, using a specially modified cannulation technique as well as ³¹P NMR spectroscopy. During acute exposure to 0.6 kPa CO₂, S. officinalis rapidly increased its blood [HCO₃ ⁻] to 10.4 mM through active ion-transport processes, and partially compensated the hypercapnia induced respiratory acidosis. A minor decrease in intracellular pH (pH_i) and stable intracellular phosphagen levels indicated efficient pH_i regulation. We conclude that S. officinalis is not only an efficient acid–base regulator, but is also able to do so without disturbing metabolic equilibria in characteristic tissues or compromising aerobic capacities. The cuttlefish did not exhibit acute intolerance to hypercapnia that has been hypothesized for more active cephalopod species (squid). Even though blood pH (pHe) remained 0.18 pH units below control values, arterial O₂ saturation was not compromised in S. officinalis because of the comparatively lower pH sensitivity of oxygen binding to its blood pigment. This raises questions concerning the potentially broad range of sensitivity to changes in acid–base status amongst invertebrates, as well as to the underlying mechanistic origins. Further studies are needed to better characterize the connection between acid–base status and animal fitness in various marine species.     

Biogenic and Risk Elements in Wines from the Slovak Market with the Estimation of Consumer Exposure

Wine consumption delivers macroelements and microelements necessary for the proper metabolism. On the other hand, wine can be an important source of toxic metals. The aim of this study was to estimate the concentrations of Ca, Cd, Cu, Fe, Hg, Mg, Ni, Pb, and Zn in the Slovak and non-Slovak wines. The concentration of metals was evaluated with respect to the type, the alcohol content, and the age of Slovak wine. The general scheme of concentrations found was as follows Ca > Mg > Fe > Zn > Pb > Cd > Ni > Cu > Hg. The type of wine and the alcohol content do not have a significant impact on metal concentrations. Also, the age of wine has no influence on the mean concentration of metals, except for Zn. Metal concentrations in Slovak and non-Slovak wines indicate similar contents of metals, except for Ni. The contribution to both dietary reference values (DRVs) and provisional tolerable weekly intake (PTWI) evaluations in the Slovak wine suggested low dietary exposure to Ca, Cu, Fe, Mg, Ni, Zn, Cd, Hg, and Pb, respectively. However, we do not suggest that the consumption of all Slovak wines is healthy. The maximum Pb concentrations in Slovak wines exceed the maximum permitted level proposed by the European Commission. This might be proved by the results of the margin of the exposure (MOE) value evaluation in the samples containing the maximum Pb concentrations, showing a high risk of CKD and SBP in high and extreme consumption groups.     

Tobacco Smoke Exposure During Pregnancy Increases Maternal Blood Lead Levels Affecting Neonate Birth Weight

To assess the effect of lead exposure from cigarette smoke on fetal growth, blood lead concentrations were measured using inductively coupled plasma mass spectrometry in 150 healthy pregnant women. Mean lead concentrations in plasma and whole blood were significantly higher in the smoking group compared with the nonsmoking group in each trimester of pregnancy (p?<?0.001). Logistic regression analysis showed the highest impact of the number of cigarettes smoked per day for serum lead concentration (β?=?0.238; p?<?0.05), while in whole blood, it was duration of smoking before conception (β?=?0.297; p?<?0.001). Birth weight of the smoking mothers' infants was significantly lower (mean?±?SEM, 3,192?±?50.8 and 3,569?±?49.6 g, respectively; p?<?0.001) and negatively correlated with lead levels in plasma (r?=??0.38; p?<?0.001) and in whole blood (r?=??0.27; p?<?0.001). Therefore, it is suggested that smoking during pregnancy increases lead concentrations in maternal blood. Fetal exposure to low doses of lead in utero may be a serious risk factor causing lower birth weight.     

Brachypodium distachyon: making hay with a wild grass

Brachypodium distachyon is a wild grass with a short life cycle. Although it is related to small grain cereals such as wheat, its genome is only a fraction of the size. A draft genome sequence is currently available, and molecular and genetic tools have been developed for transformation, mutagenesis and gene mapping. Accessions collected from across its ancestral range show a surprising degree of phenotypic variation in many traits, including those implicated in domestication of the cereals. Thus, given its rapid cycling time and ease of cultivation, Brachypodium will be a useful model for investigating problems in grass biology.     

The application of fluorescence spectroscopy to organic matter characterisation in drinking water treatment

Key to effective disinfection byproduct (DBP) management is source water control and management, and more specifically, organic matter (OM) control and management. However, the content and character of OM in source waters is spatially and temporally variable, and the prediction of its composition is challenging. Water treatment companies require adequate analytical techniques for OM characterisation to maintain the operation of the water supply and treatment systems adjusted to constantly changing environmental conditions. There is a requirement, therefore, for an improved understanding of OM composition and character in source water, how that composition and character varies with flow conditions, and how this impacts on drinking water treatment. This paper demonstrates that fluorescence spectroscopy offers a potential alternative to other analytical methods of OM characterisation. The advantages of fluorescence include rapid, sensitive and selective characterisation of OM, no sample pre-treatment, small sample volume, and the potential for on-line monitoring incorporation. Fluorescence can provide useful information on OM reactivity and treatability together with an indication of the OM sources (allochthonous or autochthonous). The paper discusses a body of literature which has identified relationships between fluorescence spectra and OM physico-chemical properties (i.e. degree of hydrophobicity, microbial content), has applied fluorescence spectroscopy to characterise the changes in OM upon disinfection, and has related the fluorescence properties to DBP formation. Further work is required in the robust management of data arising from fluorescence spectroscopy analysis and, in particular, Excitation Emission Matrices. Consideration must be given as to how the data might best be employed to greatest effect on a routine basis at WTW.     

Structural studies of the exopolysaccharide consisting of a nonasaccharide repeating unit isolated from Lactobacillus rhamnosus KL37B

A novel structure of exopolysaccharide from the lactic acid bacteria (LAB) Lactobacillus rhamnosus KL37B, from the human intestinal flora, is described. During the structural investigation of the exopolysaccharide it was found that the repeating unit is a nonasaccharide, which is the largest repeating unit found in LAB exopolysaccharides to date. The polysaccharide material was prepared by TCA extraction of a bacterial cell mass, purified by anion-exchange and gel permeation chromatography and characterized using chemical and enzymatic methods. On the basis of monosaccharide and methylation analysis and also 1D and 2D ¹H and ¹³C NMR spectroscopy the exopolysaccharide was shown to be composed of the following nonasaccharide repeating unit:The physicochemical cell surface study and adhesive properties indicated distinct surface properties of Lactobacillus rhamnosus strain KL37B with high adhesive abilities to Caco-2 cells, hydrophobicity and slime production, in comparison to other Lactobacillus strains used as controls.