A comparison of three bacterial phosphonoacetate hydrolases from different environmental sources

Cleavage of the carbon-phosphorus bond of the xenobiotic phosphonoacetate by phosphonoacetate hydrolase: represents a novel route for the microbial metabolism of organophosphonates, and is unique in that it: is substrate-inducible and its expression is independent of the phosphate status of the cell. The enzyme has previously only been demonstrated in cell extracts of Pseudomonas fluorescens 23F. Phosphonoacetate hydrolase activity is now reported in extracts of environmental Curtobacterium sp. and Pseudomonas sp. isolates capable of the phosphate-insensitive mineralization of phosphonoacetate as the sole source of carbon, energy and phosphorus at concentrations up to 40 mmol l(-1) and 100 mmol l(-1), respectively. The enzymes in both strains were similarly inducible by phosphonoacetate and had a unique specificity ibr this substrate. However, they differed significantly from each other, and from the previously described Ps. fluorescens 23F enzyme, in respect of their apparent molecular masses, temperature optima, thermostability, sensitivity to inhibition by chelating agents and by structural analogues of phosphonoacetate, and in their affinities for the substrate.

Isotopic identification of the sources of lead contamination for white storks (Ciconia ciconia) in a marshland ecosystem (Doñana, S.W. Spain)

White storks (Ciconia ciconia) fed in contaminated waters resulting from the Aznacollar acid mining-sludge spillage into the R. Guadiamar, which feeds the eastern flank of the Guadalquivir marshes (Doñana), S.W. Spain. The sludge was rich in a range of toxic elements, and in organic pollutants such as the aromatic amines. Storks did not exhibit elevated metals in their blood immediately following the accident, but chick blood collected the year following the accident showed genotoxic damage compared to the controls. In this study lead isotope analysis was used to assess if the storks had ingested sludge-derived contaminants. The sludge lead isotope ratio was distinct from that of the Doñana sediments. The stork blood lead isotope ratios exactly matched that of the sludge. It was concluded that the storks had ingested sludge-derived contaminants. A detailed study of the lead contamination along the R. Guadiamar and the R. Guadalquivir (of which the Guadiamar is a tributary) was also conducted to place the white stork colony lead exposure in the context of the spatial contamination of the storks' habitat.

Age-related changes in non-receptor dependent generation of reactive oxygen species from phagocytes of healthy adults

Several authors have shown that neutrophil generation of reactive oxygen species (ROS) declines with advancing age. Similar changes have also been suggested in monocytes. In both cases alterations in second messenger activity have been implicated as the most likely explanation for these observations. The aim of this study was to investigate the effect of age on phagocyte ROS generation, stimulated by the direct activation of protein kinase C (PKC). Venous blood was drawn from normal healthy subjects, cells were separated on a double density gradient into mononuclear and polymorphonuclear (pmn) cells. Phorbol myristate acetate (PMA) was employed as a cell stimulus. Superoxide generation was measured by cytochrome c reduction and myeloperoxidase (MPO) products by measurement of peak luminol chemiluminescence (CL). Fifty-eight subjects, 25 males and 33 females, were studied, median age 49 years (range 26-88 years). Polymorphonuclear cell superoxide generation was significantly higher in males and there was a trend towards higher pmn MPO product generation in males. Using Spearman's ranked correlation coefficient, monocyte superoxide generation was negatively correlated with age (r = -0.473, P <0.001). No changes in the generation of MPO products was found. There were also trends towards a negative correlation of pmn cytochrome c reduction and peak luminol CL with age in males but not females. Since PMA directly activates protein kinase C, reduced monocyte superoxide generation with increasing age appears to be related to alterations in the ROS generating system downstream of the cell receptor. Impaired monocyte superoxide generation may have implications for non-specific defence against certain infections and early tumour growth in the elderly. Factors underlying these changes in monocyte function therefore require further study.

Uses of expertise:Sources, quotes, and voice in the reporting of genetics in the news

Science journalists call upon experts for background and for clarification and comment on scientific findings. This paper examines how science writers choose and use experts, and it focuses on several cases of reporting about genetics and behavior. Our research included two sources of data: interviews with 15 science reporters and three print media samples of coverage of genetics and behavior - alcoholism (between 1980-1995), homosexuality (in 1993 and 1995), and mental illness (between 1970-1995). Science reporters seek relevant and specific experts for nearly every story. Good sources are knowledgeable, are connected to prestigious institutions, are direct and articulate and don't overqualify statements, and they return phone calls. The mean number of experts quoted was 2.8 per story, differing for alcoholism (3.5), homosexuality (2.8), and mental illness (2.6). Researchers and scientists predominated among experts quoted. Quotes were used to provide context, give legitimization, as explication, to provide a kind of balance, and to outline implications. For the homosexuality sample, a significantly greater percentage of activists and advocates were quoted (21 percent compared with 5 percent and 1 percent in other samples, X <0.0001). "Lay" quotes for alcoholism and mental illness were minimal. Except for homosexuality, whose advocates are organized, those "affected" do not have a voice in genetics news stories.

From Negation to Agreement: Revisiting the Problem of Sources for Socio-Historical Linguistics

In this article we review recent work on the history of French negation in relation to three key issues in socio-historical linguistics: identifying appropriate sources, interpreting scant or anomalous data, and interpreting generational differences in historical data. We then turn to a new case study, that of verbal agreement with la plupart, to see whether this can shed fresh light on these issues. We argue that organising data according to the author’s date of birth is methodologically sounder than according to date of publication. We explore the extent to which different genres and text types reflect changing patterns of usage and suggest that additional, different case-studies are required in order to make more secure generalisations about the reliability of different sources.

Infection systems biology:from reactive to proactive (P4) medicine

This short review establishes the conceptual bases and discusses the principal aspects of P4-shorthand for predictive, preventive, personalized and participatory medicine-medicine, in the framework of infectious diseases. P4 medicine is a new way to approach medical care; instead of acting when the patient is sick, physicians will be able to detect early warnings of disease to take early action. Furthermore, people might even be able to adjust their lifestyles to prevent disease. P4 medicine is fuelled by systems approaches to disease, including methods for personalized genome sequencing and new computational techniques for building dynamic disease predictive networks from massive amounts of data from a variety of OMICs. An excellent example of the effectiveness of the P4 medicine approach is the change in cancer treatments. Emphasis is placed on early detection, followed by genotyping of the patient to use the most adequate treatment according to the genetic background. Cardiovascular diseases and perhaps even neurodegenerative disorders will be the next targets for P4 medicine. The application of P4 medicine to infectious diseases is still in its infancy, but is a promising field that will provide much benefit to both the patients and the health-care system.

Reactive dye adsorption onto a novel mesoporous carbon

A new mesoporous carbon (MCSG60) was developed using an inexpensive commercial mesoporous silica gel as a template and sucrose as the carbon source. The surface area, porosity and density of the carbon were determined. The material possesses a high specific surface area and pore volume accessible for most typical aqueous pollutants. The adsorbent material was tested in a batch dye adsorption system. The behaviour of three reactive dyes adsorbed onto MCSG60 was evaluated (Naphthol Blue Black, NBB; Reactive Black 5, RB5; and Remazol Brilliant Blue R, RBBR). The maximum adsorption capacities obtained for the dyes were: 270. mg/g for NBB; 270. mg/g for RB5; and 280. mg/g for RBBR. Kinetic studies indicated that the adsorption process onto the mesoporous carbon was rapid and that equilibrium was reached in less than 1. h for all the dye systems investigated. Further batch experiments showed MCSG60 successfully adsorbed the dyes over a wide pH range and at low adsorbate concentration. The adsorption potential of MCSG60 for dye removal was further evaluated using a fixed-bed adsorption column. © 2013 Elsevier B.V.

Removal of natural hormones in dairy farm wastewater using reactive and sorptive materials

The objective of this study was to examine the estrogen and androgen hormone removal efficiency of reactive (Connelly zero-valent iron (ZVI), Gotthart Maier ZVI) and sorptive (AquaSorb 101 granular activated carbon (GAC) and OrganoLoc PM-100 organo clay (OC)) materials from HPLC grade water and constructed wetland system (CWS) treated dairy farm wastewater. Batch test studies were performed and hormone concentration analysis carried out using highly sensitive reporter gene assays (RGAs). The results showed that hormonal interaction with these materials is selective for individual classes of hormones. Connelly ZVI and AquaSorb 101 GAC were more efficient in removing testosterone (Te) than 17?-estradiol (E2) and showed faster removal rates of estrogen and androgen than the other materials. Gotthart Maier ZVI was more efficient in removing E2 than Te. OrganoLoc PM-100 OC achieved the lowest final concentration of E2 equivalent (EEQ) and provided maximum removal of both estrogens and androgens.

Metabolomic Profiling of In Vivo Plasma Responses to DioxinAssociated Dietary Contaminant Exposure in Rats: Implications for Identification of Sources of Animal and Human Exposure

Dioxin contamination of the food chain typically occurs when cocktails of combustion residues or polychlorinated biphenyl (PCB) containing oils become incorporated into animal feed. These highly toxic compounds are bioaccumulative with small amounts posing a major health risk. The ability to identify animal exposure to these compounds prior to their entry into the food chain may be an invaluable tool to safeguard public health. Dioxin-like compounds act by a common mode of action and this suggests that markers or patterns of response may facilitate identification of exposed animals. However, secondary co-contaminating compounds present in typical dioxin sources may affect responses to compounds. This study has investigated for the first time the potential of a metabolomics platform to distinguish between animals exposed to different sources of dioxin contamination through their diet. Sprague-Dawley rats were given feed containing dioxin-like toxins from hospital incinerator soot, a common PCB oil standard and pure 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (normalized at 0.1 µg/kg TEQ) and acquired plasma was subsequently biochemically profiled using ultra high performance liquid chromatography (UPLC) quadropole time-of-flight-mass spectrometry (QTof-MS). An OPLS-DA model was generated from acquired metabolite fingerprints and validated which allowed classification of plasma from individual animals into the four dietary exposure study groups with a level of accuracy of 97-100%. A set of 24 ions of importance to the prediction model, and which had levels significantly altered between feeding groups, were positively identified as deriving from eight identifiable metabolites including lysophosphatidylcholine (16:0) and tyrosine. This study demonstrates the enormous potential of metabolomic-based profiling to provide a powerful and reliable tool for the detection of dioxin exposure in food-producing animals.

Electronic, structural, and reactive properties of ultrathin aluminum oxide films on Pt(111)

Low-energy electron diffraction, X-ray photoelectron spectroscopy, high-resolution electron energy-loss spectroscopy, scanning tunneling microscopy, and temperature-programmed reaction spectrometry results are reported for the structural and reactive behavior of alumina films grown on Pt(111) as a function of thickness and oxidation temperature. Submonolayer Al films undergo compete oxidation at 300 K, annealing at 1100 K resulting in formation of somewhat distorted crystalline gamma-alumina, Thicker deposits require 800 K oxidation to produce Al2O3, and these too undergo crystallization at 800 K, yielding islands of apparently undistorted gamma-alumina on the Pt(111) surface. Oxidation of a p(2 x 2) Pt3Al surface alloy occurs only at>800 K, resulting in Al extraction, These alumina films on Pt(lll) markedly increase the coverage of adsorbed SO4 resulting from SO2 chemisorption onto oxygen-precovered surfaces. This results in enhanced propane uptake and subsequent reactivity relative to SO4/Pt(111). A bifunctional mechanism is proposed to account for our observations, and the relevance of these to an understanding of the corresponding dispersed systems is discussed.

Cross-sectional associations of C-reactive protein with vascular risk factors and vascular complications in the DCCT/EDIC cohort

To determine the relationships between C-reactive protein (CRP) levels and features of Type 1 diabetes.