Emerging organic compounds in European groundwater.

In Europe, emerging organic compounds (EOCs) in groundwater is a growing research area. Prioritisation for monitoring EOCs in Europe was formalised in 2019 through the development of the first voluntary groundwater watch list (GWWL). Despite this, groundwater occurrence data in the peer reviewed literature for Europe has not been reviewed to date. Questions surrounding the effect, toxicity, movement in the subsurface and unsaturated zone make the process of regulating EOC use difficult. The aim in Europe is to develop a unified strategy for the classification, and prioritisation of EOCs to be monitored in groundwater. This paper compiles evidence from the recent published studies from across Europe, since 2012, when the last major literature global review of EOCs in groundwater took place. A total of 39 studies were identified for review based on specific selection criteria (geography, publication date, sample size>10, inclusion of EOCs data). Data on specific compounds, and associated meta-data, are compiled and reviewed. The two most frequently detected EOCs, carbamazepine and caffeine, occurred in groundwater at concentrations of up to 2.3 and 14.8 µg/L, respectively. The most frequently reported category of compounds were 'Pharmaceuticals'; a highly studied group with 135 compounds identified within 31 of the 39 studies. In Europe, the majority of reviewed studies (23) were at a regional scale, looking specifically at EOCs in a specific city or aquifer. The use of analytical methods is not uniform across Europe, and this inevitably influences the current assessment of EOCs in groundwater. A correlation between the number of compounds analysed for, and the number detected in groundwater highlights the need for further studies, especially larger-scale studies throughout Europe. For the development of EU and national regulation, further work is required to understand the occurrence and impacts of EOCs in groundwater throughout Europe and elsewhere.

Metabolic blood profile of beef heifers during oestrous and non-oestrous states.

Haematological metabolic profiles in heifers could contribute to the development of proxies for oestrous detection and provide clues to further characterize biological changes during oestrus. One hundred and seven beef heifers were observed for oestrous behaviour twice daily for 124 days. Feed intake and productive performance (body weight and composition) traits were measured, and feed efficiency was determined using residual feed intake (kg DM/day). Blood plasma samples were collected when signs of oestrus were observed and every 30 ± 2 days. Heifers were considered in oestrus (n = 71) when plasma progesterone concentrations were <0.6 ng/ml. Least square means of blood metabolic parameters were compared between oestrous and non-oestrous states and within oestrous groups according to performance traits and age. Heifers in oestrus exhibited higher concentrations of alkaline phosphatase, aspartate aminotransferase (AST), beta-hydroxybutyric acid, creatine kinase (CK) and triiodothyronine (T3) than heifers in non-oestrus. Heifers in oestrus revealed lower osmolality and concentrations of calcium, sodium and total protein than during non-oestrus. Younger (and smaller) heifers had greater concentrations of CK, gamma-glutamyl transferase (GGT), glucose and sodium than the older heifers. Heifers with lower fatness had increased osmolality and concentrations of cholesterol, CK, phosphorus, sodium and reduced T3 levels. Feed efficient heifers had greater levels of AST, cholesterol and GGT than inefficient heifers. Blood plasma parameters may be complementary to oestrous detection upon further validation; effects of age, feed efficiency, body size and body composition should be considered to optimize this haematological assessment.

Nitrogen losses in anoxic marine sediments driven by Thioploca-anammox bacterial consortia.

Ninety per cent of marine organic matter burial occurs in continental margin sediments, where a substantial fraction of organic carbon escapes oxidation and enters long-term geologic storage within sedimentary rocks. In such environments, microbial metabolism is limited by the diffusive supply of electron acceptors. One strategy to optimize energy yields in a resource-limited habitat is symbiotic metabolite exchange among microbial associations. Thermodynamic and geochemical considerations indicate that microbial co-metabolisms are likely to play a critical part in sedimentary organic carbon cycling. Yet only one association, between methanotrophic archaea and sulphate-reducing bacteria, has been demonstrated in marine sediments in situ, and little is known of the role of microbial symbiotic interactions in other sedimentary biogeochemical cycles. Here we report in situ molecular and incubation-based evidence for a novel symbiotic consortium between two chemolithotrophic bacteria--anaerobic ammonium-oxidizing (anammox) bacteria and the nitrate-sequestering sulphur-oxidizing Thioploca species--in anoxic sediments of the Soledad basin at the Mexican Pacific margin. A mass balance of benthic solute fluxes and the corresponding nitrogen isotope composition of nitrate and ammonium fluxes indicate that anammox bacteria rely on Thioploca species for the supply of metabolic substrates and account for about 57 ± 21 per cent of the total benthic N2 production. We show that Thioploca-anammox symbiosis intensifies benthic fixed nitrogen losses in anoxic sediments, bypassing diffusion-imposed limitations by efficiently coupling the carbon, nitrogen and sulphur cycles.

Radiofrequency ablation of osteoid osteoma: outcomes from the West of Scotland.

BACKGROUND: Osteoid osteoma is a classically described benign bone tumour. Traditionally, the surgical treatment of choice was excision, but this can have significant morbidity. Percutaneous radiofrequency ablation (RFA) has grown in popularity as an alternative treatment. This study reports the outcomes using this technique in our regional bone tumour unit. METHODS: Between May 2003 and October 2007, 14 patients underwent CT-guided RFA. All patients were subsequently offered follow-up in the out-patient clinic. Outcomes were taken from the Scottish Bone Tumour Registry database. RESULTS: Eleven patients (78.6%) had complete resolution of symptoms after one RFA. Three (21.4%) cases were unsuccessful but one of these was due to technical failure. All three of the above patients had complete relief of symptoms after one further RFA. One (7.1%) patient initially had complete relief of symptoms, but suffered recurrence after 9 months. This patient also had a second curative treatment. CONCLUSION: Percutaneous RFA for osteoid osteoma is an attractive treatment due to its efficacy and low morbidity. Our results showed a primary success rate of 78.6%, a secondary success rate of 100% (after one additional procedure). Our results add to the growing literature supporting RFA as the preferred treatment for osteoid osteoma.

Enhancing patient recovery following lower limb arthroplasty with a modern wound dressing: a prospective, comparative audit.

OBJECTIVE: To assess current wound care practice, implement a potentially improved regimen and re-evaluate practice. METHOD: Two prospective clinical audits were performed over a 6-month period, involving 100 patients undergoing hip or knee arthroplasty. Fifty consecutive patients with traditional dressings (Mepore; Mölnlycke) were evaluated prior to a change in practice to a modern dressing (Aquacel Surgical; ConvaTec). Fifty consecutive patients were then evaluated with the new dressing to complete the audit cycle. Clinical outcome measures were wear time, number of changes, blister rate and length of hospital stay. Statistical comparisons were performed using Mann Whitney or Fisher's exact test (statistical significance p < 0.05). RESULTS: Wear time for the traditional dressing (2 days) was significantly shorter than for the modern dressing (7 days; p < 0.001), and required more changes (0 vs 3; p < 0.001). Twenty per cent of patients developed blisters with the traditional dressing compared with 4% with the modern dressing (p=0.028). Median length of stay was the same for the modern dressing (4 days) compared with the traditional dressing (4 days). In the modern dressing group, 75% of patients were discharged by day 4, whereas in the traditional group this took until day 6. CONCLUSION: This audit highlights the problems associated with traditional dressings with frequent early dressing changes, blistering and delayed discharge. These adverse outcomes can be minimised with a modern dressing specifically designed for the demands of lower limb arthroplasty. Units planning to implement enhanced recovery regimens should consider adopting this dressing to avoid compromising patient discharge. DECLARATION OF INTEREST: There were no external sources of funding for this audit; however, one author (JC) received reimbursement of expenses to attend and present work at educational conferences from ConvaTec.

Emergency department visits involving nonmedical use of selected prescription drugs in the United States, 2004-2008.

This report, adapted from the lead article in the June 10, 2010, issue of Morbidity and Mortality Weekly Reports, describes the alarming increase in overdose deaths involving prescription drugs. Oxycodone, hydrocodone, and methadone were the drugs most highly implicated. Data were derived from the federal Drug Abuse Warning Network (Dawn). Other drugs commonly used in managing pain patients, including benzodiazepines and muscle relaxants, also were implicated.

The NADH oxidase from Pyrococcus furiosus. Implications for the protection of anaerobic hyperthermophiles against oxidative stress.

A wealth of H(2)O-producing NADH oxidase (NOX) homologues have been discovered in the genomes of the hyperthermophilic Archaea, including two homologues in the genome of Pyrococcus furiosus which have been designated as NOX1 and NOX2. In order to investigate the function of NOX1, the structural gene encoding NOX1 was cloned from the genome of P. furiosus and expressed in Escherichia coli, and the resulting recombinant enzyme (rNOX1) was purified to homogeneity. The enzyme is a thermostable flavoprotein that can be reconstituted only with FAD. rNOX1 catalyzes the oxidation of NADH, producing both H(2)O(2) and H(2)O as reduction products of O(2) (O(2) + 1-2NADH + 1-2H(+) --> 1-2NAD(+) + H(2)O(2) or 2H(2)O). To our knowledge, this is the first NADH oxidase found to produce both H(2)O(2) and H(2)O. The enzyme exhibits a low K(m) for NADH (< 4 microm), and shows little or no reaction with NADPH. Transcriptional analyses demonstrated that NOX1 is constitutively expressed regardless of the carbon source and a single promoter was identified 25 bp upstream of the nox1 gene by primer extension. Although P. furiosus is a strict anaerobe, it may tolerate oxygen to some extent and we anticipate NOX1 to be involved in the response to oxygen at high temperatures.

Additive fabrication and the mechanisms of nucleation and growth in chemical vapor deposition processes.

In this Account, we present several representative studies of thin-film growth by chemical vapor deposition, with particular emphasis given to elucidating the mechanistic, energetic, and structural aspects of nucleation and growth. These understandings have allowed us to develop new methods to deposit patterned, as opposed to blanket, thin films. We show how such procedures can be exploited to effect the directed assembly (i.e., the additive fabrication) of a device architecture.

Analysis of the kinetic and redox properties of the NADH peroxidase R303M mutant: correlation with the crystal structure.

The crystal structure of the flavoprotein NADH peroxidase shows that the Arg303 side chain forms a hydrogen bond with the active-site His10 imidazole and is therefore likely to influence the catalytic mechanism. Dithionite titration of an R303M mutant [E(FAD, Cys42-sulfenic acid)] yields a two-electron reduced intermediate (EH(2)) with enhanced flavin fluorescence and almost no charge-transfer absorbance at pH 7.0; the pK(a) for the nascent Cys42-SH is increased by over 3.5 units in comparison with the wild-type EH(2) pK(a) of Cys42-SOH. The crystal structure of the R303M peroxidase has been refined at 2.45 A resolution. In addition to eliminating the Arg303 interactions with His10 and Glu14, the mutant exhibits a significant change in the conformation of the Cys42-SOH side chain relative to FAD and His10 in particular. These and other results provide a detailed understanding of Arg303 and its role in the structure and mechanism of this unique flavoprotein peroxidase.

Protein-sulfenic acids: diverse roles for an unlikely player in enzyme catalysis and redox regulation.

While it has been known for more than 20 years that unusually stable cysteine-sulfenic acid (Cys-SOH) derivatives can be introduced in selected proteins by mild oxidation, only recently have chemical and crystallographic evidence for functional Cys-SOH been presented with native proteins such as NADH peroxidase and NADH oxidase, nitrile hydratase, and the hORF6 and AhpC peroxiredoxins. In addition, Cys-SOH forms of protein tyrosine phosphatases and glutathione reductase have been suggested to play key roles in the reversible inhibition of these enzymes during tyrosine phosphorylation-dependent signal transduction events and nitrosative stress, respectively. Substantial chemical data have also been presented which implicate Cys-SOH in redox regulation of transcription factors such as Fos and Jun (activator protein-1) and bovine papillomavirus-1 E2 protein. Functionally, the Cys-SOHs in NADH peroxidase, NADH oxidase, and the peroxiredoxins serve as either catalytically essential redox centers or transient intermediates during peroxide reduction. In nitrile hydratase, the active-site Cys-SOH functions in both iron coordination and NO binding but does not play any catalytic redox role. In Fos and Jun and the E2 protein, on the other hand, a key Cys-SH serves as a sensor for intracellular redox status; reversible oxidation to Cys-SOH as proposed inhibits the corresponding DNA binding activity. These functional Cys-SOHs have roles in diverse cellular processes, including signal transduction, oxygen metabolism and the oxidative stress response, and transcriptional regulation, as well as in the industrial production of acrylamide, and their detailed analyses are beginning to provide the chemical foundation necessary for understanding protein-SOH stabilization and function.

13C NMR analysis of the cysteine-sulfenic acid redox center of enterococcal NADH peroxidase.

In order to characterize the native Cys42-sulfenic acid redox center of the flavoprotein NADH peroxidase by NMR, an expression protocol has been developed which yields the [3-13C]Cys42-labeled protein in 100 mg quantities. Difference spectra of the labeled minus unlabeled oxidized enzyme (E) give a peak at 41.3 ppm (relative to dioxane) which represents the Cys42-sulfenic acid. Reduction of labeled E with 1 equiv of NADH gives the air-stable two-electron reduced (EH2) species, and oxidized minus reduced difference spectra give maxima and minima at 41.3 and 30.8 ppm, respectively, corresponding to the Cys42-sulfenic acid and -thiolate species. Peroxide inactivation of E, which has previously been attributed to oxidation of the Cys42-sulfenic acid to the Cys42-sulfinic and/or sulfonic acid states, gives rise to a new maximum in the difference spectrum of Einactive minus E at 57.0 ppm. A similar expression protocol was used to obtain the [ring-2-13C]His-labeled peroxidase HHAA mutant (His10His23Ala87Ala258); the spectral change over the pH range 5.8-7. 8 is attributed to deprotonation of the surface-exposed His23. Furthermore, replacement of Arg303, which is hydrogen bonded to His10, has no effect on the 13C spectrum. These results provide direct evidence in support of the peroxidase Cys42-sulfenic acid/thiol redox cycle and add significantly to our structure-based understanding of protein-sulfenic acid stabilization and function.

The active-site histidine-10 of enterococcal NADH peroxidase is not essential for catalytic activity.

In order to test the proposal [Stehle, T., Claiborne, A., & Schulz, G. E. (1993) Eur. J. Biochem. 211, 221-226] that the active-site His10 of NADH peroxidase functions as an essential acid-base catalyst, we have analyzed mutants in which this residue has been replaced by Gln or Ala. The k(cat) values for both H10Q and H10A peroxidases, and the pH profile for k(cat) with H10Q, are very similar to those observed with wild-type peroxidase. Both mutants, however, exhibit K(m)(H2O2) values much higher (50-70-fold) than that for wild-type enzyme, and stopped-flow analysis of the H2O2 reactivity of two-electron reduced H10Q demonstrates that this difference is due to a 150-fold decrease in the second-order rate constant for this reaction with the mutant. Stopped-flow analyses also confirm that reduction of the enzyme by NADH is essentially unaffected by His10 replacement and remains largely rate-limiting in turnover; the formation of an E.NADH intermediate in the conversion of E-->EH2 is confirmed by diode-array spectral analyses with H10A. Both H10Q and H10A mutants, in their oxidized E(FAD, Cys42-sulfenic acid) forms, exhibit enhanced long-wavelength absorbance bands (lambda(max) = 650 nm and 550 nm, respectively), which most likely reflect perturbations in a charge-transfer interaction between the Cys42-sulfenic acid and FAD. Combined with the 50-fold increase in the second-order rate constant for H2O2 inactivation (via Cys42-sulfenic acid oxidation) of the H10Q mutant, these observations support the proposal that His10 functions in part to stabilize the unusual Cys42-sulfenic acid redox center within the active-site environment.

Mechanism of reconstitution of brewers' yeast pyruvate decarboxylase with thiamin diphosphate and magnesium.

Reconstitution of apo-pyruvate decarboxylase isozymes (PDC, EC 4.1.1.1) from Saccharomyces carlsbergensis was investigated by determination of the steady-state kinetics of the reaction with thiamin diphosphate (TDP) and Mg2+ in the presence and absence of substrate (pyruvate) or allosteric effector (pyruvamide). Reconstitution of the PDC isozyme mixture and alpha 4 isozyme (alpha 4-PDC) exhibits biphasic kinetics with 52 +/- 11% of the PDC reacting with k1 = (1.0 +/- 0.3) x 10(-2) s-1 and 48 +/- 12% of the PDC reacting with k2 = (1.1 +/- 0.6) x 10(-1) s-1 when TDP (KTDP = 0.5 +/- 0.2 mM) is added to apo-PDC equilibrated with saturating Mg2+. PDC reconstitution exhibits first-order kinetics with k1 = (1.6 +/- 0.5) x 10(-2) s-1 upon addition of Mg2+ (KMg2+ = 0.2 +/- 0.1 mM) to apo-PDC equilibrated with saturating TDP. Biphasic kinetics for the PDC isozymes provides evidence that apo-PDC reconstitution with TDP and Mg2+ involves two pathways, TDP binding followed by Mg2+ (k1) or Mg2+ binding followed by TDP (k2). This is supported by a change in reconstitution pathway with the order of cofactor addition and is inconsistent with a single pathway involving ordered binding of the metal ion followed by TDP. The presence of pyruvamide has no significant effect on the rate constants for apo-PDC reconstitution and favors the k2 pathway; pyruvate decreases the value of k2 < or = 3-fold and has no effect on the value of k1.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of the kinetic mechanism of enterococcal NADH peroxidase reveals catalytic roles for NADH complexes with both oxidized and two-electron-reduced enzyme forms.

Anaerobic titrations of the two-electron-reduced NADH peroxidase (EH2) with NADH and 3-acetylpyridine adenine dinucleotide (AcPyADH) yield the respective complexes without significant formation of the four-electron-reduced enzyme (EH4). Further analysis of the EH2/EH4 redox couple, however, yields a midpoint potential of -312 mV for the free enzyme at pH 7. The catalytic mechanism of the peroxidase has been evaluated with a combination of kinetic and spectroscopic approaches, including initial velocity and enzyme-monitored turnover measurements, anaerobic stopped-flow studies of the reactions of both oxidized enzyme (E) and EH2 with NADH and AcPyADH, and diode-array spectral analyses of both the reduction of E-->EH2 by NADH and the formation of EH2.NADH. Overall, these results are consistent with rapid formation of an E.NADH complex with distinct spectral properties and a rate-limiting hydride transfer step that yields EH2, with no direct evidence for intermediate FADH2 formation. The EH2.NADH complex described previously [Poole, L. B., & Claiborne, A. (1986) J. Biol. Chem. 261, 14525-14533] is not catalytically competent and reacts relatively slowly with H2O2. Stopped-flow analyses do, however, support the very rapid formation of an EH2.NADH* intermediate, with spectral properties that distinguish it from the static EH2.NADH form, and yield a first-order rate constant for the conversion between the two species that is smaller than kcat. The combined rapid-reaction and steady-state data are best accommodated by a limiting type of ternary complex mechanism very similar to that proposed previously [Parsonage, D., Miller, H., Ross, R.P., & Claiborne, A. (1993) J. Biol. Chem. 268, 3161-3167].

Qualitative research with a Kenyan flavour.

PIP: The Essential Drugs Program in Kenya's Ministry of Health included a qualitative research phase of focus group discussions (FGDs) to assess the communication needs in educating the public about responsible essential drug use. This article discusses the general parameters of FGDs, and specific outcomes of essential drug FGDs and the evaluation of the health education tools generated in the FGDs. The purpose of the pilot project was to develop effective materials on the correct use of drug regimens and promoting authorized drug providers. FGDs were used as a quick and relatively inexpensive means of gauging a target audience's beliefs and practices. The facilitator of the group directed discussion and probed for participants views on the community's needs, and forms of expression. (Drawing on positive social customs within a culture helps bridge the difference between local perceptions and knowledge.) Pretesting of draft materials in FGDs assured the ability to reach the target audience. These 2 methods contributed to the project's success by involving the target group as experts in providing useful information, fostering a sense of ownership and commitment, and building a relationship between the staff and target group that renewed dedication and willingness to cooperate. Program staff conducted 19 FGDs with 171 clients and 9 FGDs with 63 providers, and also interviewed 36 providers and observed in 4 locations client/provider exchanges. The results showed that client were unaware of the importance of strict compliance with a drug regimen, and consequences of ineffectiveness. Clients were uneasy about side effects, and purchased drugs from unauthorized dealers. The 3 messages to be promoted were 1) return to the clinic or hospital if drug problems arise, 2) use only authorized providers, and 3) follow directions carefully and completely. It was also decided that posters and audio cassette were the communication modes. A description of the materials developed is described. 24 health centers in 3 districts received the materials. A 3 month evaluation was conducted, after which time quantitative information was analyzed. Behavioral changes were observed in the returns to the clinic for more information, and closing of some unauthorized clinics and loss of business, and fewer complaints of lingering illness. Communication, trust, and good health care resulted.^ieng

Assessing the acceptability of NORPLANT implants in four countries: findings from focus group research.

In 1986-87, a qualitative research project was conducted in the Dominican Republic, Egypt, Indonesia, and Thailand to expand understanding of the acceptability of NORPLANT contraceptive implants beyond inferences made on the basis of continuation rates. In each of the four study sites, focus group discussions or in-depth interviews were held with potential acceptors, current NORPLANT users, discontinuers, husbands of women in these three groups, and service providers. Nonclinical participants generally had little formal education and lived primarily in urban or semi-urban areas where NORPLANT has been available for at least five years. The study focused on attitudes, perceptions, and experiences of each group regarding NORPLANT implants. Results suggest that factors having an impact on the acceptability of NORPLANT implants fall into three general categories: medical/technical, cultural/religious, and informational/educational. This article discusses each of these categories, including programmatic implications of the findings, and puts forward recommendations for enhancing NORPLANT introduction efforts on the basis of these findings.

PIP: In 1986-87, a qualitative research project was done in Thailand, Egypt, Indonesia, and the Dominican Republic to expand knowledge of the acceptability of NORPLANT contraceptive implants beyond continuation rates. In each of the 4 studies, in-depth interviews or focus group discussions were held with current NORPLANT users, potential acceptors, discontinuers, husband of women in the 3 groups, and service providers. The 4 countries were chosen because of their diverse cultures and religions. Most participants favored family planning. Many had used other contraceptives. Men and women in all countries were worried that oral female contraceptive agents (the pill) caused cancer. There were many objections to the IUD. In all countries but Thailand, there was little knowledge of NORPLANT. In the Dominican Republic, NORPLANT was used mostly as a child spacing method. In Indonesia, it was used for child spacing and termination of childbearing. Perceived advantages were alike in all countries. Pain during insertion and removal was a big concern of potential users. Men and women in all countries said that religion and traditional beliefs did not influence their family planning decisions. But many said that religion influenced their tolerance of side effects. In Egypt and Indonesia sterilization is unpopular because it is seen as violating Islamic law. Irregular bleeding was the major side effect and the main reason for discontinuation. Many satisfied users felt that the advantaged outweighed the side effects. Primary reasons for removal in all countries were irregular bleeding, amenorrhea, and the desire to give birth. The need for information was mentioned in all countries. In Egypt, Indonesia, and Thailand services providers reported the need for more thorough training in insertion and removal as well as continuing education sessions.