bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of Type 2 Diabetes and Outcomes in Patients With Heart Failure: A Nested Case–Control Study From the U.K. General Practice Research Database
Authors: MacDonald Michael R. , Eurich Dean T. , Majumdar Sumit R. , Lewsey James D. , Bhagra Sai , Jhund Pardeep S. , Petrie Mark C. , McMurray John J.V. , Petrie John R. , McAlister Finlay A.
Published: March 2010

OBJECTIVE

Diabetes and heart failure commonly coexist, and prior studies have suggested better outcomes with metformin than other antidiabetic agents. We designed this study to determine whether this association reflects a beneficial effect of metformin or a harmful effect of other agents.

RESEARCH DESIGN AND METHODS

We performed a case-control study nested within the U.K. General Practice Research Database cohort in which diagnoses were assigned by each patient's primary care physician. Case subjects were patients 35 years or older, newly diagnosed with both heart failure and diabetes after January 1988, and who died prior to October 2007. Control subjects were matched to case subjects based on age, sex, clinic site, calendar year, and duration of follow-up. Analyses were adjusted for comorbidities, A1C, renal function, and BMI.

RESULTS

The duration of concurrent diabetes and heart failure was 2.8 years (SD 2.6) in our 1,633 case subjects and 1,633 control subjects (mean age 78 years, 53% male). Compared with patients who were not exposed to antidiabetic drugs, the current use of metformin monotherapy (adjusted odds ratio 0.65 [0.48–0.87]) or metformin with or without other agents (0.72 [0.59–0.90]) was associated with lower mortality; however, use of other antidiabetic drugs or insulin was not associated with all-cause mortality. Conversely, the use of ACE inhibitors/angiotensin receptor blockers (0.55 [0.45–0.68]) and β-blockers (0.76 [0.61–0.95]) were associated with reduced mortality.

CONCLUSIONS

Our results confirm the benefits of trial-proven anti-failure therapies in patients with diabetes and support the use of metformin-based strategies to lower glucose.
Alterations in Retinal Microvascular Geometry in Young Type 1 Diabetes
Authors: Sasongko Muhammad Bayu , Wang Jie Jin , Donaghue Kim C. , Cheung Ning , Benitez-Aguirre Paul , Jenkins Alicia , Hsu Wynne , Lee Mong-Li , Wong Tien Y.
Published: March 2010

OBJECTIVE

To describe retinal microvascular geometric parameters in young patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Patients with type 1 diabetes (aged 12–20 years) had clinical assessments and retinal photography following standardized protocol at a tertiary-care hospital in Sydney. Retinal microvascular geometry, including arteriolar and venular tortuosity, branching angles, optimality deviation, and length-to-diameter ratio (LDR), were measured from digitized photographs. Associations of these geometric characteristics with diabetes duration, A1C level, systolic blood pressure (SBP), and other risk factors were assessed.

RESULTS

Of 1,159 patients enrolled, 944 (81.4%) had gradable photographs and 170 (14.7%) had retinopathy. Older age was associated with decreased arteriolar (P = 0.024) and venular (P = 0.002) tortuosity, and female subjects had larger arteriolar branching angle than male subjects (P = 0.03). After adjusting for age and sex, longer diabetes duration was associated with larger arteriolar branching angle (P ≤ 0.001) and increased arteriolar optimality deviation (P = 0.018), higher A1C was associated with increased arteriolar tortuosity (>8.5 vs. ≤8.5%, P = 0.008), higher SBP was associated with decreased arteriolar LDR (P = 0.002), and higher total cholesterol levels were associated with increased arteriolar LDR (P = 0.044) and decreased venular optimality deviation (P = 0.044). These associations remained after controlling for A1C, retinal vessel caliber, and retinopathy status and were seen in subjects without retinopathy.

CONCLUSIONS

Key diabetes-related factors affect retinal microvascular geometry in young type 1 diabetes, even in those without evidence of retinopathy. These early retinal alterations may be markers of diabetes microvascular complications.
Physical Therapists' Perceptions of Ease of Care in Patients Receiving 2 Forms of Analgesia After Total Hip Arthroplasty
Authors: Bourne Michael H. , Chelly Jacques E. , Damaraju C.V. , Nelson Winnie W. , Schein Jeff R. , Hewitt David J.
Published: March 2010

Background

Pain management modalities that facilitate patient mobility may contribute to recovery after total hip replacement (THR) surgery.

Objective

The aim of this study was to evaluate the impact of morphine intravenous (IV) patient-controlled analgesia (PCA) and the fentanyl iontophoretic transdermal system (fentanyl ITS) on physical therapists' ability to complete care tasks for patients after THR.

Design

The data were from an open-label, randomized, multicenter, active-control phase IIIb clinical trial.

Methods

The settings were 52 US-based teaching and community hospitals. The patients were ≥18 years of age (mean [SEM]: 62.8 [0.6] years in the fentanyl ITS group and 62.9 [0.6] years in the morphine IV PCA group); had an American Society of Anesthesiologists physical status of I, II, or III; and were scheduled to undergo primary unilateral THR surgery. The patients were randomized to receive analgesia for up to 72 hours via the fentanyl ITS (40 μg of fentanyl over 10 minutes for up to 6 doses per hour for 24 hours or 80 doses per system, whichever occurred first) or morphine IV PCA (1-mg bolus doses [with a 5-minute lockout interval between doses] for up to 10 doses per hour for 24 hours). All patients received the usual treatment administered by physical therapists. After each therapy session, physical therapists completed a validated Physical Therapist Ease-of-Care Questionnaire, which included time efficiency and convenience subscales (lower scores indicated more positive responses) and a satisfaction subscale (a higher score indicated a more positive response). Therapists whose average scores were ≤2 on all items of the time efficiency and convenience subscales or ≥4 on both items of the satisfaction subscale were considered responders.

Results

Higher percentages of physical therapists were responders for the fentanyl ITS than for morphine IV PCA on the subscales that assessed time efficiency (84.9% and 59.1%, respectively), convenience (86.6% and 71.2%, respectively), and satisfaction (54.3% and 30.5%, respectively). Higher percentages of physical therapists favored the fentanyl ITS than favored morphine IV PCA.

Limitations

The trial was limited by its open-label design, and physical therapists were more familiar with IV PCA than with the fentanyl ITS.

Conclusions

The findings demonstrate benefits to physical therapists of using the fentanyl ITS over morphine IV PCA in terms of time efficiency, convenience, and satisfaction.
Spondyloarthritis in a Patient With Unilateral Buttock Pain and History of Crohn Disease
Authors: Coronado Rogelio A. , Sheets Charles Z. , Cook Chad E. , Boissonnault William G.
Published: March 2010

Background and Purpose

Patients with inflammatory spinal conditions related to spondyloarthritis are rarely seen by primary care practitioners. However, patients with a history of inflammatory bowel disease and chronic low back or buttock pain should be examined carefully for the presence of spondyloarthritis, as proper management may include referral to a rheumatologist and appropriate medical intervention.

Case Description

A 27-year-old woman with a 6-month history of posterior buttock pain was referred for physical therapy with a diagnosis of piriformis syndrome. During the second physical therapy visit, a nonmechanical source of lumbopelvic pain was suspected, and the patient was referred for medical consultation. The patient underwent evaluation by a rheumatologist and was eventually diagnosed with spondyloarthritis associated with inflammatory bowel disease.

Outcomes

The patient initiated treatment with anti-tumor necrosis factor medication to address the spondyloarthritis. Medical management resulted in significant improvement in all outcome measures.

Discussion

Clinical suspicion of spondyloarthritis is raised when specific historical, examination, and imaging findings are present. The posttest probability of spondyloarthritis is increased with the presence of inflammatory back pain and specific spondyloarthritic features, such as a positive history of inflammatory bowel disease, radiographic evidence of sacroiliitis, and improvement with anti-inflammatory medication. Referral of patients with these findings for a rheumatological evaluation is warranted, as these diseases are managed effectively with specific treatment.
Treatment of Molluscum Contagiosum with Cantharidin: A Practical Approach
Authors: Mathes Erin F.D. , Frieden Ilona J.
Published: March 2010

Molluscum contagiosum is very common. In this article we discuss the use of cantharidin as a treatment option for molluscum contagiosum and give detailed information about distribution sources, how to apply it, and caveats regarding its use. Molluscum contagiosum is a common viral disease of childhood caused by a poxvirus, which presents with small, firm, dome-shaped, umbilicated papules. It is generally benign and self-limited, with spontaneous resolution within 6 months to several years. Watchful waiting can often be an appropriate management strategy; however, some patients either desire or require treatment. Reasons for actively treating molluscum contagiosum may include alleviation of discomfort and itching (particularly in patients where an eczematous eruption — the so-called “molluscum eczema” — is seen in association) or in patients with ongoing atopic dermatitis where more lesions are likely to be present. Other reasons for treatment include limitation of spread to other areas and people, prevention of scarring and superinfection, and elimination of the social stigma of visible lesions. No one treatment is uniformly effective.

Treatment options include destructive therapies (curettage, cryotherapy, cantharidin, and keratolytics, among others), immunomodulators (imiquimod, cimetidine, and
Candida
antigen), and antivirals (cidofovir). In this article we discuss and describe our first-line treatment approach for those molluscum needing treatment — cantharidin.
Practical Application of the Nutrition Recommendations for the Prevention and Treatment of Obesity in Pediatric Primary Care
Authors: Parks Elizabeth Prout , Kumanyika Shiriki , Stettler Nicolas
Published: March 2010

CME EDUCATIONAL OBJECTIVES

1.

Identify the nutrition recommendations for the prevention and treatment of childhood overweight and obesity.

2.

Discuss the best use of behavioral strategies to implement changes in nutrition and feeding behaviors.

3.

Define the major challenges to adhering to nutrition recommendations and provide strategies to address these challenges.
Metabolic Syndrome in the Pediatric Population: A Short Overview
Authors: Varda Natasa Marcun , Gregoric Alojz
Published: March 2010

The metabolic syndrome (MS) in adults is defined as a concurrence of obesity, disturbed glucose and insulin metabolism, hypertension and dyslipidemia, and is associated with increased morbidity and mortality from cardiovascular diseases and type 2 diabetes. Studies now indicate that many of its components are also present in children and adolescents. Moreover, the clustering of these risk factors has been documented in some children, who are at increased cardiovascular risk in adulthood. The MS is highly prevalent among overweight children and adolescents. Identifying these children is important for early prevention and treatment of different components of the syndrome. The first-line treatment comprises lifestyle modification consisting of diet and exercise. The most effective tool for prevention of the MS is to stop the development of childhood obesity. The first attempt of consensus-based pediatric diagnostic criteria was published in 2007 by the International Diabetes Federation. Nevertheless, national prevalence data, based on uniform pediatric definition, protocols for prevention, early recognition and effective treatment of pediatric MS are still needed. The aim of this article is to provide a short overview of the diagnosis and treatment options of childhood MS, as well as to present the relationships between MS and its individual components.
Methylenetetrahydrofolate Reductase Homozygous Mutation in a Young Boy with Cerebellar Infarction
Authors: Spalice Alberto , Del Balzo Francesca , Perla Francesco Massimo , Properzi Enrico , Carducci Carla , Antonozzi Italo , Iannetti Paola
Published: March 2010

Posterior circulation vascular occlusive disease in children is a rare and uncommonly reported event. Among the numerous risk factors, the methylenetetrahydrofolate reductase (MTHFR) mutation is considered to be a common genetic cause of thrombosis in adults and children. Recently, a link between the MTHFR mutation and cerebrovascular disorders was reported in children. Diffusion tensor imaging (DTI) is a great improvement on magnetic resonance imaging (MRI), making the in vivo anatomical and pathological study of the brain and its fibers possible. In our patient cerebellar infarction was associated with MTHFR mutation and, in a standard neurological examination, DTI revealed normal white matter tracts.
A 5-year Old Male with “leukemic Form” of Disseminated Post-Transplant Lymphoproliferative Disorder
Authors: Haque Saadiya A. , Kallakury Bhaskar , Shad Aziza , Snyder Kristen
Published: March 2010

Post-transplant lymphoproliferative disorder (PTLD) represents an abnormal lymphoid proliferation that occurs in recipients of solid organ or bone marrow allograft[...]
More Variations on the Sierpiński Sieve
Authors: Hare Kevin G.
Published: March 2010

This paper answers a question of Broomhead, Montaldi and Sidorov about the existence of gaskets of a particular type related to the Sierpiński sieve. These gaskets are given by iterated function systems that do not satisfy the open set condition. We use the methods of Ngai and Wang to compute the dimension of these gaskets.
Predicting the toxicity of major ions in seawater to mysid shrimp (Mysidopsis bahia), sheepshead minnow (Cyprinodon variegatus), and inland silverside minnow (Menidia beryllina)
Authors: Pillard David A , DuFresne Doree L , Caudle Dan D , Tietge Joseph E , Evans James M
Published: March 2010

Although marine organisms are naturally adapted to salinities well above those of freshwater, elevated concentrations of specific ions have been shown to cause adverse effects on some saltwater species. Because some ions are also physiologically essential, a deficiency of these ions can also cause significant effects. To provide a predictive tool to assess toxicity associated with major ions, mysid shrimp (Mysidopsis bahia), sheepshead minnows (Cyprinodon variegatus), and inland silverside minnows (Menidia beryllina) were exposed to saline solutions containing calcium, magnesium, potassium, strontium, bicarbonate, borate, bromide, and sulfate at concentrations above and below what would be found in seawater. Solution salinity was maintained at approximately 31‰ by increasing or decreasing sodium and chloride concentrations. Logistic regression models were developed with both the ion molar concentrations and ion activity. Toxicity to all three species was observed when either a deficiency or an excess of potassium and calcium occurred. Significant mortality occurred in all species when exposed to excess concentrations of magnesium, bicarbonate, and borate. The response to the remaining ions varied with species. Sheepshead minnows were the most tolerant of both deficient and elevated levels of the different ions. Mysid shrimp and inland silverside minnows demonstrated similar sensitivities to several ions, but silverside minnow response was more variable. As a result, the logistic models that predict inland silverside minnow survival generally were less robust than for the other two species.
Influence of complexation with chloride on the responses of a lux-marked bacteria bioassay to cadmium, copper, lead, and mercury
Authors: Sarin Charoon , Hall Jennifer M , Cotter-Howells Janet , Killham Ken , Cresser Malcolm S
Published: March 2010

The toxicity of a heavy metal in solution to a microorganism depends not only on its concentration but also on pH and the concentrations of any aqueous complexing ligands in the microorganism's environment. This paper reports on the use of different inorganic resuscitation media and effect of the chloride ion, Cl−, on the bioluminescence response of a bacterial biosensor, Escherichia coli HB101 (pUCD607), to four metals: Cd, Cu, Hg, and Pb. The toxicity tests were conducted at pH 4, using 0.1 M KNO3 as resuscitation medium and adding KCl to investigate effect of Cl− concentration. The species distributions of metals as a function of Cl− concentration were calculated using GeoChem-PC. Resuscitation in 0.1 M KC1 gave significantly higher light output than that in 0.1 M KNO3, demonstrating that Cl− in the resuscitation medium has a direct effect on the bioluminescence response of the E. coli biosensor. Increasing concentrations of Cl− ions increased the toxicity of Hg, apparently because of the formation of HgCl−3, and increased the toxicity of Pb because of PbCl+ formation. The toxicity of Cu decreased at high Cl− concentrations as free Cu2+ decreased, in accordance with the free ion model. Concentrations of Cl− had no significant effect on the toxicity of Cd. This study clearly demonstrates that the chloro-complexes of some heavy metals can be toxic and, for Pb and Hg, more toxic than the free ion.
Correlating environmental partitioning properties of organic compounds: The three solubility approach
Authors: Cole John G , Mackay Donald
Published: March 2010

It is suggested that in addition to correlating the environmental partitioning characteristics of chemicals as partition coefficients, it is also valuable to correlate them as solubilities or pseudo-solubilities. These solubilities are essentially convenient, readily understood, and in many cases, measurable expressions of single-phase activity coefficients. To illustrate this approach, a novel, three solubility, quantitative structure-property relationships (or QSAR) approach is described for correlating the physico-chemical parameters in which the solubilities or pseudo-solubilities of individual chemicals in the liquid or super-cooled liquid state, both individually and as homologous series, are compiled and correlated as a function of temperature in the three primary media of air, water, and octanol and possibly in other relevant media. These quantities, which are deduced from measured partition coefficients, solubilities, and vapor pressures, comprise a consistent data set that can be used to estimate a variety of environmentally relevant partition coefficients. The approach is demonstrated in detail for the chlorobenzenes and in a preliminary fashion for a variety of persistent and hydrophobic substances. The merits of this approach as a supplement to the conventional use of partition coefficients are discussed.
Toxic responses of medaka, D-rR strain, to polychlorinatednaphthalene mixtures after embryonic exposure by in ovo nanoinjection: A partial life-cycle assessment
Authors: Villalobos Sergio A , Papoulias Diana M , Meadows John , Blankenship Alan L , Pastva Stephanie D , Kannan Kurunthachalam , Hinton David E , Tillitt Donald E , Giesy John P
Published: March 2010

Polychlorinated naphthalenes (PCNs) are organic compounds with some chemical properties and uses similar to polychlo-rinated biphenyls. Polychlorinated naphthalenes have been detected in biota from certain aquatic environments. The toxicities of several PCN technical mixtures (Halowax) to medaka (Oryzias latipes) were determined by use of an embryo nanoinjection method. Medaka eggs (early gastrula) were injected with 0.5 nl of triolein (vehicle control) or 0.5 nl of four to five graded doses (0.3–30 ng/egg) of Halowax 1014, Halowax 1013, or Halowax 1051 in triolein. Following exposure, embryos developed, and fry were reared to sexual maturity (4 months), at which time they were euthanized. Responses were evaluated as early life stage (ELS) and early adult life stage (EALS) assessments. For ELS, lethality and sublethal alterations in embryos and larvae (<16 d old), such as craniofacial, cardiovascular, and myoskeletal deformities and abnormal or delayed hatch, were monitored for the first 9 d, and a dose severity index was computed. The EALS assessment examined the survival of 16-d-old larvae until early adulthood (123 ± 3 d old), including gonadosomatic index (GSI) and morphometry. Halowax 1014 was found to be the most toxic mixture (LD50 4.2 ng/egg), whereas Halowax 1013 and 1051 were significantly less toxic (LD50s could not be determined). The gonadosomatic index of females was significantly less in fish dosed with Halowax 1014 or 1051. The LD50 for medaka embryos nanoinjected with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is about 0.75 pg/egg. Thus, Halowax 1014 was 5,585-fold less potent than TCDD. For Halowax 1014, ELS assessments accurately predicted the results of EALS assessments.
Biochemical and developmental effects of dietary exposure to polychlorinated biphenyls 126 and 153 in common tern chicks (Sterna hirundo)
Authors: Bosveld Albertus T. C. , Nieboer Ruud , de Bont Alex , Mennen Judith , Murk Albertinka J , Feyk Lori A , Giesy John P , van den Berg Martin
Published: March 2010

Effects of PCBs weres studied in common terns (Sterna hirundo). Hatchlings from eggs collected from Dutch breeding colonies and incubated artificially were raised to an age of 21 d. The birds were fed fish spiked with PCB 126 alone or in combination with PCB 153 (1:1,000), resulting in concentrations in the food ranging from 0.01 to 1.2 ng toxic equivalents (TEQs)/g wet weight. The most sensitive effect parameter was induction of hepatic CYP1A-associated ethoxyresorufin-O-deethylation (EROD) activity, and a nonlinear concentration–effect relationship could be determined with the TEQ concentration (r = 0.967, p < 0.001). Induction of pentoxyresorufin-O-depenthylation and methoxyresorufin-O-demethylation activities was observed at dose levels similar to those that induced EROD activity. The estimated lowest-observed-effect level for induction of CYP1A in the common tern was approx. 25 ng TEQ/g liver lipid, which was caused by concentrations in the food of approx. 0.6 ng TEQ/g fish wet weight. At these concentrations, a 50% reduction in plasma total thyroxine compared with controls also was observed. Concentrations of plasma total thyroxine were negatively correlated with hepatic TEQ concentrations (r = 0.523, p < 0.01), but the shape of the nonlinear concentration–effect relationship did not allow determination of a lowest-observed-effect level. No changes were found for hepatic hydroxylation of testosterone. Bursa weight decreased proportionally to hepatic concentrations of TEQs (r = 0.433, p < 0.05) and showed a similar sensitivity as that observed for EROD activity. Concentrations of TEQs in The Netherlands are approx. 0.1 ng TEQ/g wet weight fish, which is approximately six times lower than the lowest-observed-effect level for CYP1A induction in terns as estimated in this study. It is concluded that no overt effects on growth and development in the common tern are expected with this background exposure during the posthatch period.
Seasonal concentrations of organic contaminants at the fall line of the Susquehanna River basin and estimated fluxes to northern Chesapeake Bay, USA
Authors: Foster Gregory D , Lippa Katrice A , Miller Cherie V
Published: March 2010

Riverine fluxes of several pesticides and other organic contaminants from above the fall line of the Susquehanna River basin to northern Chesapeake Bay, USA, were quantified in 1994. Base flow and storm flow samples collected at the fall line of the river from February to December 1994 were analyzed for both dissolved and particulate phase contaminants. Measured concentrations of the organonitrogen and organophosphorus pesticides varied mainly in response to the timing of their application to agricultural fields. Conversely, the concentrations of the more particle-sorptive contaminants such as polychlorinated biphenyls (PCBs), organochlorine (OC) insecticides, and polycyclic aromatic hydrocarbons (PAHs) were more directly correlated with river flow throughout the year. Annual fluxes were almost entirely in the dissolved phase for the organonitrogen and organophosphorus pesticides, distributed between the dissolved and particulate phases for the PCBs and OC insecticides, and primarily in the particulate phase for the PAHs.
Development and evaluation of consensus-based sediment effect concentrations for polychlorinated biphenyls
Authors: MacDonald Donald D , Dipinto Lisa M , Field Jay , Ingersoll Christopher G , Lvong Edward R , Swartz Richard C
Published: March 2010

Sediment-quality guidelines (SQGs) have been published for polychlorinated biphenyls (PCBs) using both empirical and theoretical approaches. Empirically based guidelines have been developed using the screening-level concentration, effects range, effects level, and apparent effects threshold approaches. Theoretically based guidelines have been developed using the equilibrium-partitioning approach. Empirically-based guidelines were classified into three general categories, in accordance with their original narrative intents, and used to develop three consensus-based sediment effect concentrations (SECs) for total PCBs (tPCBs), including a threshold effect concentration, a midrange effect concentration, and an extreme effect concentration. Consensus-based SECs were derived because they estimate the central tendency of the published SQGs and, thus, reconcile the guidance values that have been derived using various approaches. Initially, consensus-based SECs for tPCBs were developed separately for freshwater sediments and for marine and estuarine sediments. Because the respective SECs were statistically similar, the underlying SQGs were subsequently merged and used to formulate more generally applicable SECs. The three consensus-based SECs were then evaluated for reliability using matching sediment chemistry and toxicity data from field studies, dose-response data from spiked-sediment toxicity tests, and SQGs derived from the equilibrium-partitioning approach. The results of this evaluation demonstrated that the consensus-based SECs can accurately predict both the presence and absence of toxicity in field-collected sediments. Importantly, the incidence of toxicity increases incrementally with increasing concentrations of tPCBs. Moreover, the consensus-based SECs are comparable to the chronic toxicity thresholds that have been estimated from dose-response data and equilibrium-partitioning models. Therefore, consensus-based SECs provide a unifying synthesis of existing SQGs, reflect causal rather than correlative effects, and accurately predict sediment toxicity in PCB-contaminated sediments.
Importance of contamination history for understanding toxicity of copper to earthworm Eisenia fetica (Oligochaeta: Annelida), using neutral-red retention assay
Authors: Scott-Fordsmand Janeck J , Weeks Jason M , Hopkin Stephen P
Published: March 2010

Eisenia fetida was exposed in the laboratory to a range of elevated soil copper (Cu) concentrations under two different contamination histories. An EC10 for reproduction was observed at 34 mg Cu/kg for soil spiked with Cu 1 d prior to running the experiment (newly spiked soil). Soil contaminated with Cu in the field more than 70 years previously (field-contaminated soil) caused a 10% decrease in reproduction at 248 mg Cu/kg. Survival and cocoon wet weights were not affected by soil concentrations up to 1,400 mg Cu/kg under either contamination history. Adult growth was reduced at 428 mg Cu/kg (EC10) in newly spiked soil but not in field-contaminated soil at concentrations up to 1,400 mg Cu/kg. The contamination history, as well as the toxicological parameter, was important in the interpretation of the outcome of a standard laboratory toxicity test. The lysosomal membrane stability of coelomocytes, measured as neutral-red retention time (NRR-time), was reduced at soil Cu concentrations lower than those affecting reproduction and demonstrated a dose–response relationship. The NRR-time was more severely reduced in worms exposed to newly Cu-spiked soil (EC10 = 8 mg Cu/kg) than worms exposed to field-contaminated soil (EC10 = 69 mg Cu/kg). The NRR-time reflected the bioactive Cu fraction, showing a good correlation with reproduction under both contamination histories.
A study of the structure and metal tolerance of the soil microbial community six years after cessation of sewage sludge applications
Authors: Witter Ernst , Gong Ping , Bååth Erland , Marstorp Håkan
Published: March 2010

Changes in soil microbial community structure and development of metal tolerance as a result of past applications of unamended sewage sludge and metal-amended sewage sludge were found in soils of a long-term field experiment at Braunschweig, Germany. Both the rate of sewage sludge application and metal amendment affected the size and activity of the microbial biomass and had caused changes in microbial community structure as seen by differences in phospholipid fatty acid (PLFA) profiles. Past sewage sludge additions and metal amendment had an effect on the microbial respiratory response to 15 different C substrates, but both the magnitude and the direction of this response were substrate dependent. Differences between the soils in the respiratory response to the substrates were therefore probably largely determined by differences in the composition of the microbial consortia utilizing the substrates. The level of metal tolerance of the soil bacterial community determined by the thymidine incorporation technique and that of the microbial consortium growing on glucose in situ (determined from respiration measurements) increased with the level of metal contamination of the soil. Metal tolerance measurements could identify the metal with the largest toxicity effect in this experiment with multiple metal-polluted sewage sludge.
Inhibition of methanogenesis by C1- and C2-polychlorinated aliphatic hydrocarbons
Authors: Yu Zhongtang , Smith Geoffrey B
Published: March 2010

Inhibition of methanogenesis in ananaerobic wastewater digester sample by four common polychlorinated aliphatic hydrocarbons (dichloromethane, chloroform, trichloroethylene, and perchloroethylene) was investigated. Chloroform was shown to be the most inhibitory, and an aqueous concentration of chloroform as low as 0.09 mg/L completely inhibited methanogenesis. Dichloromethane inhibited methanogenesis at 3.9 mg/L, trichloroethylene at 18 mg/L, but 14.5 mg/L of perchloroethylene did not inhibit methanogenesis. The following order of inhibition was determined (in descending potencies): chloroform ≫ dichloromethane > trichloroethylene > perchloroethylene. The wastewater consortium dechlorinated chloroform, trichloroethylene, and perchloroethylene but not dichloromethane. Our results suggest that inhibition of methanogenesis and dechlorination is determined by both the extent of chlorination and the molecular structure of polychlorinated hydrocarbons. A model is presented, proposing that polychlorinated hydrocarbons inhibit methanogenesis directly and/or indirectly by binding to corrinoid/porphinoid enzymes and free corrinoids/porphinoids in the cell, respectively. Polychlorinated methanes would lead to both direct and indirect inhibition, whereas polychlorinated ethylenes would only inhibit methanogenesis indirectly. The model predicts that direct inhibition of methanogenesis is more potent than indirect inhibition.
Ecological and human health risks at an outdoor firing range
Authors: Peddicord Richard K , LaKind Judy S
Published: March 2010

This is the first report in the refereed literature of a quantitative ecological and human health risk assessment at an outdoor recreational shooting range. Contaminants of concern (COC) included lead, other metals, and polycyclic aromatic hydrocarbons (PAH) associated with the clay targets on the shotgun range. Ecological receptors included raptors, deer, foxes, birds, and small mammals. The risk associated with potential incidental ingestion of lead shot by mammals was estimated for the first time. With the exception of lead, risks were minimal to all ecological receptors from all COC acting through all exposure pathways. Lead posed minimal risk to raptors, foxes, or deer. Lead in dietary items posed a small risk to individual birds. The only substantive risk was to individual small mammals and gritingesting birds from the incidental ingestion of lead shot within the shotfall zone at the trap and skeet range. Although effects associated with lead ingestion may occur at the level of individual organisms, ecological impacts are not expected at the population, community, or ecosystem level. This is because density-dependent compensation mechanisms would likely offset any site-related loss of a few individuals that might occur. Human receptors included shooters, range workers, and trespassers. Cancer risks to all receptors from all COC via all exposure pathways were less than 10−4, generally considered an acceptable upper bound excess lifetime cancer risk to an individual. The only noncarcinogenic risk of HQ > 1 was associated with inhalation of copper by those engaged in the voluntary activity of shooting. Two approaches were taken to modeling blood lead in children associated with intermittent exposure. Under the most likely exposure scenario, the mean blood lead level of trespassing children was approx. 2 μg/dL, with less than 1% of children exceeding the 10-μg/dL level of concern. Higher blood lead levels could be possible if children were to trespass in off-limit areas of the shooting range.
Modeling the photolysis of ammonium dinitramide in natural waters
Authors: Beretvas Michelle K , Hassett John P , Burns Susan E , Basford Trisha M
Published: March 2010

Photolytic rate constants for the novel energetic compoundammonium dinitramide(ADNweredetermined in order to understand the fate of ADN in natural bodies of water. Quantum yields were measured between 290 and 400 nm using a lamp system, and these values were combined with absorption of light in a water column to model photolysis rates as a function of depth. The validity of this model was tested in field trials in Onondaga Lake, Syracuse, New York, USA. For a summertime irradiation, half-lives ranged from ∼6 min at the surface to —15 years at a depth of 2 m. The predicted and observed degradation rates of ADN were sufficiently similar to justify use of this simple model. It was also found that the degradation of ADN is not enhanced to any measurable degree by sensitized photoreactions in humic solutions. Thus, the photodegradation of ADN can be predicted throughout the water column of a body of water.
Induction of hepatic cytochrome p450 activities by toxaphene in rat and japanese quail
Authors: Drenth Henk-Jan , Van Oevelen Chris J C , Buitenhuis Christian J K , Berg Martin Van Den
Published: March 2010

Several organochlorine compounds can induce hepatic cytochrome P450 activities. We exposed female Japanese quail and female rats to a single oral dose of technical toxaphene ranging from 0.012 to 40 mg/kg body weight to investigate a possible dose-response relationship for P450 activity induction. The hepatic microsomal alkoxyresorufin dealkylation and steroid hydrox-ylation activities (testosterone, 17β-estradiol) were determined. Only in the highest dose groups (40 mg/kg) of rats and Japanese quail were some P450 activities induced. Pentoxyresorufin-O-dealkylation, formation of 15β-hydroxytestosterone, and formation of 2-hydroxyestradiol were induced significantly (p ≤ 0.05) in rat hepatic microsomes with a factor of 3.9, 3.1, and 2.4, respectively. In Japanese quail hepatic microsomes, the formation rates of 6β-, 15α-, 16β-hydroxytestosterone and androstenedione were induced significantly (p ≤ 0.05) with a factor of 2.4, 6.5, 3.3, and 1.6, respectively. It is concluded that exposure to toxaphene can lead to specific P450 activity induction in rats and Japanese quail but only at doses near reported LD50 values. Because reported toxaphene levels in biota are lower compared with liver residue levels that we have measured in our study, we conclude that it is unlikely that P450 activity induction occurs in wildlife higher in the food chain due to environmental toxaphene exposure.
Contaminant-related disruption of vitamin a dynamics in free-ranging harbor seal (Phoca vitulina) pups from british columbia, canada, and washington state, usa
Authors: Simms Wendy , Jeffries Steven , Ikonomou Michael , Ross Peter S
Published: March 2010

Marine mammals can bioaccumulate high concentrations of lipophilic environmental contaminants, such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-para-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), through the diet. Both laboratory and wildlife studies have shown that these persistent chemicals can disrupt the regulation of vitamin A (retinol), a dietary hormone required for immune function, reproduction, growth, and development. To determine whether environmental contaminants affect the circulatory vitamin A dynamics of free-ranging harbor seals (Phoca vitulina), we live-captured 61 pups from British Columbia, Canada, and Washington State, USA, and obtained blood and blubber biopsy samples. Harbor seal pups from Washington State were six times more contaminated with total PCBs than pups from British Columbia and had significantly lower circulatory retinol levels. However, when data were corrected for differences in nursing status and analyzed as ungrouped sets of data, circulatory retinol levels were positively correlated with contaminant levels in the blubber of nonnursing pups. This increase in retinol may have resulted from a mobilization of liver vitamin A stores into circulation following exposure to milk-derived contaminants; this has been observed in laboratory animals exposed experimentally. The contaminant-related disruption of vitamin A dynamics observed in our study occurs at a time when vitamin A is required for growth and development.
Morphological and metabolic changes in common carp,Cyprinus carpio, during short-term copper exposure: Interactions between Cu2+ and plasma cortisol elevation
Authors: De Boeck Gudrun , Vlaeminck Andrea , Balm Paul H M , Lock Robert A C , De Wachter Bart , Blust Ronny
Published: March 2010

The effects of increased endogenous cortisol levels were compared with those of sublethal copper exposurein the freshwater common carp, Cyprinus carpio. Fish were exposed to either increased levels of endogenous cortisol (200 ng/ml) or sublethal copper (1.9 μM) alone or were pretreated by elevating plasma cortisol levels prior to copper exposure to assess whether interactions between both treatments occurred. Effects induced by increased cortisol levels included increased Na+/K+-adenosine triphosphate (ATPase) activity and increased plasma Na+ and plasma osmolarity, while copper exposure induced anaerobic metabolism, gill damage, decreasing Na+/K+-ATPase activity, decreasing plasma ion levels, and blood thickening. Pretreatment of copperexposed fish with cortisol partially protected these fish by reducing the copper-induced decrease in Na+/K+-ATPase activity. Overall, the results obtained in this study argue against a major role for cortisol as an intermediate for the toxic effects of copper.
Anaerobic biodegradation of alkanes by enriched consortia under four different reducing conditions
Authors: So Chi Ming , Young Lily Y
Published: March 2010

Enrichments of alkane-degrading microorganisms were established under sulfate-reducing, denitrifying, iron-reducing, and methanogenic conditions using an estuarine sediment. The sulfate-reducing and denitrifying enrichments mineralized [1-14C]hexadecane to 14CO2. Degradation was coupled to sulfate reduction and denitrification, as indicated by the ratios of hexadecane degraded to the electron acceptors reduced. Dependence of hexadecane degradation by the sulfate-reducing enrichments on sulfate reduction was also shown. The results indicate the existence of diverse microbial communities capable of alkane degradation in the sediment studied.
Probabilistic risk assessment of cotton pyrethroids: IV. Landscape-Level exposure characterization
Authors: Travis Kim Z , Hendley Paul
Published: March 2010

Aquatic exposure arising from the use of pyrethroid insecticides on cotton in the United States was estimated as part of an extensive pyrethroid aquatic risk assessment. The exposure analysis was based on the standard U.S. Environmental Protection Agency tier II regulatory scenario for cotton, which assumes a 1-ha pond surrounded by 10 ha of treated crop, with high levels of runoff, erosion, and drift entering the pond. This regulatory scenario was modified to include simplified landscape-level information on the proximity of cotton to ponds derived from a remote sensing study. This scenario also accounts for the no-spray buffers between pyrethroid applications and surface waters mandated on all cotton pyrethroid labels (which differentiate applications made by air and by ground-based equipment), and for the percentage of cotton area that is treated with pyrethroids. Incorporation of these landscape-level factors into the analysis reduced the predicted aquatic exposure concentrations approximately 50- to 100fold. Because many other conservative assumptions in the original tier II exposure analysis were not revised, the modified exposure predictions are still overestimates of true field exposure concentrations.
The relation between extrapolated risk, expressed as potentially affected fraction, and community effects, expressed as pollution-induced community tolerance
Authors: Van Beelen Patrick , Fleuren-Kemilä Arja K , Aldenberg Tom
Published: March 2010

The results of toxicity tests can be used to calculate the potentially affected fraction (PAF) of species in an ecosystem at a given pollutant concentration using statistical extrapolation methods. The PAF curve indicates the fraction of species from the original community that may become inhibited at each elevated pollutant concentration and is a measure of the ecotoxicological risk. Pollution-induced community tolerance (PICT) is a true community response that is measured under controlled conditions in the laboratory, using organisms from contaminated field sites. Microorganisms from experimental field plots with added Zn were exposed to various concentrations of Zn in the laboratory and the mineralization of 14C acetate was monitored. Microorganisms from plots with Zn concentrations above 124 mg/kg showed a significant increase in the effect concentration 10% (EC10) and, therefore, had a significant PICT. The pore-water concentrations of Zn in these field soils were in the same magnitude as the EC10 of the microorganisms from these soils. The PAF curve was calculated from previously reported toxicity tests with five different microbial species using the average and the standard deviation of the logarithmically transformed EC10 values. The average sensitivity of this PAF curve was similar to the EC50 of the acetate mineralization curve from the field plot without added Zn2+, but the PAF curve was less steep. Our experiments indicated that 27 to 84% of the original microbial species were inhibited at Zn concentrations from 334 to 1,858 mg/kg soil, respectively. Our results suggest that the PICT method can now also be used to quantify the fraction of the original species composition that is inhibited at a specific pollutant concentration.
Bioavailability of lab-contaminated and native polycyclic aromatic hydrocarbons to the amphipodCorophium volutatorrelates to chemical desorption
Authors: Kraaij Rik (H.) , Ciarelli Silvana , Tolls Johannes , Kater Belinda J , Belfroid Angelique
Published: March 2010

In the present study, the relationship between bioavailability of polycyclic aromatic hydrocarbons (PAHs) to benthic amphipods and the PAH desorption kinetics was examined. To that end, field-contaminated sediment was treated in three different ways. One subsample had no addition of PAHs and contained native PAHs only. To a second subsample, six PAHs (phenanthrene, fluoranthene, anthracene, pyrene, benzo[b]fluoranthene, and benzo[k]fluoranthene) were added in the laboratory. Two of the PAHs were added at higher concentrations to a third subsample, serving as a control for concentration-dependent uptake. Marine amphipods (Corophium volutator) were exposed to the three subsamples for a maximum of 25 d and were subsequently analyzed. Desorption kinetics were determined for both the lab-contaminated and the native PAHs. The biota-to-sediment accumulation factor (BSAF) values of the individual native and lab-contaminated PAHs correlated well with the rapidly desorbing fraction (R2 = 0.76). The BSAFs were 1.4 to 3.3 higher for the lab-contaminated PAHs compared with the native PAHs, while the difference between the rapidly desorbing fractions was a factor of 1.1 to 1.8. The BSAFs of the lab-contaminated PAHs in the second and third subsample were equal, indicating concentration-independent accumulation. The results suggest that lab-contaminated PAHs are more available to amphipods than native PAHs and that differences in bioavailability of lab-contaminated and native PAHs to marine amphipods are related to differences in desorption behavior.
Selectivity assessment of chlorfenvinphos reevaluated by including physiological and behavioral effects on an important beneficial insect
Authors: Alix Anne , Cortesero Anne Marie , Nénon Jean Pierre , Anger Jean Pierre
Published: March 2010

Selectivity is an important factor in identifying candidate pesticides to be used in crop protection since it characterizes chemicals that, while being effective against target pests, exert an acceptable impact on the other components of the environment. Extrapolated to an integrated pest management (IPM) context, selectivity implies that candidate pesticides may preserve the ability of beneficial insects to significantly control target pest populations. In the present study, we assess the physiological selectivity of the organophosphate chlorfenvinphos, used to protect cruciferous crops against the cabbage root fly, Delia radicum (Diptera: Anthomyiidae), by investigating both the lethal and sublethal effects exerted on its main parasitoid Trybliographa rapae (Hymenoptera: Figitidae). The comparison of the median lethal doses showed that T. rapae was at least seven times less sensitive than D. radicum to chlorfenvinphos. However, longevity of parasitoids surviving a sublethal dose was reduced by half. The potential fecundity of females was decreased by 9.6 to 22.8%. Chlorfenvinphos also induced important behavioral changes in both sexes and reduced the chances for parasitoids to mate by more than 70%. While most behavioral changes were reversible, effects on mating and on fecundity were not, thereby suggesting long-term effects on the reproduction of the parasitoid. These cumulative effects of chlorfenvinphos would have dramatic consequences on the efficacy of parasitoids contacting such doses of chlorfenvinphos in the field and therefore there is question about the intrinsic selectivity of this insecticide.