bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glial Dysfunction in Parkin Null Mice: Effects of Aging
Authors: Solano Rosa M. , Casarejos Maria J. , Menéndez-Cuervo Jamie , Rodriguez-Navarro Jose A. , García de Yébenes Justo , Mena Maria A. 
Published: January 2008

Parkin mutations in humans produce parkinsonism whose pathogenesis is related to impaired protein degradation, increased free radicals, and abnormal neurotransmitter release. The role of glia in parkin deficiency is little known. We cultured midbrain glia from wild-type (WT) and parkin knock-out (PK-KO) mice. After 18–20 din vitro, PK-KO glial cultures had less astrocytes, more microglia, reduced proliferation, and increased proapoptotic protein expression.PK-KO glia had greater levels of intracellular glutathione (GSH), increased mRNA expression of the GSH-synthesizing enzyme γ-glutamylcysteine synthetase, and greater glutathioneS-transferase and lower glutathione peroxidase activities than WT. The reverse happened in glia cultured in serum-free defined medium (EF12) or in old cultures. PK-KO glia was more susceptible than WT to transference to EF12 or neurotoxins (1-methyl-4-phenylpyridinium, blockers of GSH synthesis or catalase, inhibitors of extracellular signal-regulated kinase 1/2 and phosphatidylinositol 3 kinases), aging of the culture, or combination of these insults. PK-KO glia was less susceptible than WT to Fe2+plus H2O2and less responsive to protection by deferoxamine.Old WT glia increased the expression of heat shock protein 70, but PK-KO did not. Glia conditioned medium (GCM) from PK-KO was less neuroprotective and had lower levels of GSH than WT. GCM from WT increased the levels of dopamine markers in midbrain neuronal cultures transferred to EF12 more efficiently than GCM from PK-KO, and the difference was corrected by supplementation with GSH. PK-KO-GCM was a less powerful suppressor of apoptosis and microglia in neuronal cultures. Our data prove that abnormal glial function is critical in parkin mutations, and its role increases with aging.
Seasonal variation of polychlorinated biphenyl congeners in surficial sediment, trapped settling material, and suspended particulate material in Lake Michigan, USA
Authors: Robinson Sander D , Landrum Peter F , van Hoof Patricia L , Eadie Brian J 
Published: January 2008

Abstract
A unique time series of surface sediment, trapped settling material, and suspended particulate material polychlorinated biphenyl (PCB) samples were collected at a 45-m deep site off Grand Haven (MI, USA) over a 14-month period. Both concentrations and congener distributions remained constant for the sediments, although there were seasonal and interannual variability in the other matrices. Trapped settling material and suspended particulate material PCB concentrations were substantially lower (∼50%) in 1997 than in the samples from December 1997 through July 1998. The cause could not be determined from the data collected, but there were some very large storms during the winter–spring period of 1998, resulting in major sediment resuspension throughout the southern basin. Observed seasonal variation in PCB concentration and congener distribution on particles likely was due to the changes in particle composition. These include particle size and the source of particles (such as the amount of resuspended sediment in trapped settling material), and the role of diagenesis of the organic matter on particles.
Ultra-trace analysis of multiple endocrine-disrupting chemicals in municipal and bleached kraft mill effluents using gas chromatography–high-resolution mass spectrometry
Authors: Ikonomou Michael G , Cai Sheng-Suan , Fernandez Marc P , Blair Joel D , Fischer Maike 
Published: January 2008

Abstract
A comprehensive gas chromatographic–high-resolution mass spectrometric (GC-HRMS)–based method was developed that permitted the simultaneous determination of 30 estrogenic endocrine-disrupting chemicals (EDCs) and related compounds, including surfactants, biogenic and synthetic steroids, fecal sterols, phytoestrogens, and plasticizers, in wastewater. Features of the method include low sample volume (∼40 ml), optimized Florisil® cleanup to minimize matrix interferences and optimized analyte derivatization to improve sensitivity via GC-HRMS. Detection limits were in the low- to mid-ng/L range, and recoveries were greater than 60% for most target analytes. This new method allows for high throughput analysis of many organic wastewater contaminants in a complex matrix with relative standard deviation of less than 15% for most measurable compounds. The applicability of the method was demonstrated by examining wastewater samples from different origins. Compounds such as di(2-ethylhex-yl)phthalate, cholesterol, cholestanol, and other cholesterol derivatives were measured in much higher concentrations in untreated sewage and were reduced substantially in concentration by the treatment process. However, steroidal compounds, particularly estrone (E1), 17β-estradiol (E2), and estriol (E3), as well as plant sterols (except stigmastanol), were greater in the treated municipal wastewater versus the untreated effluent. Plant and fungi sterols, stigmastanol and ergosterol, were found largely associated with bleached kraft mill effluent (BKME) as compared to the municipal effluents.
Relative impact of coexposure compared to single-substance exposure on the biotransformation and toxicity of benzo[a]pyrene and fluoranthene in the marine polychaete Capitella sp. I
Authors: Palmqvist Annemette , Rasmussen Lene Juel , Forbes Valery E 
Published: January 2008

Abstract
Most biotransformation studies to date have concentrated on single-substance exposures. The biotransformation ability of organisms exposed to a single substance, however, may differ from that of organisms coexposed to binary or complex mixtures. The marine polychaete Capitella sp. I was exposed to either 31 μg/g dry weight sediment of benzo[a]pyrene (BaP) in a single-substance exposure or to a mixture of 31 and 28 μg/g dry weight sediment of BaP and fluoranthene (Flu), respectively (coexposure). Biotransformation capability and DNA damage were compared between treatments. Worms exposed to BaP alone accumulated total BaP equivalents to a significantly higher degree than coexposed worms (final body burden: 117.14 ± 3.52 μg BaP equivalents/g dry wt tissue and 69.78 ± 8.58 μg BaP equivalents/g dry wt tissue, respectively), probably because of a higher degree of BaP biotransformation in the latter. In addition, a larger percentage of the accumulated BaP equivalents was in the form of parent compound in worms exposed to BaP alone compared to coexposed worms on day 10 (87 and 56%, respectively). In coexposed worms, Flu was both accumulated and biotransformed to a considerably greater degree than BaP (final Flu body burden: 181.85 ± 18.46 μg Flu equivalents/g dry wt tissue, 24% as parent compound). Neither treatment resulted in significant effects on growth or DNA damage. The present study shows that the extent to which bioaccumulation factors estimated from single-substance exposures have relevance for the field situation will depend on the degree to which accumulation is influenced by the presence of other contaminants. These results therefore are relevant for assessing risks from contaminated sediments.
Early life-stage toxicity test for copper pyrithione and induction of skeletal anomaly in a teleost, the mummichog (Fundulus heteroclitus)
Authors: Mochida Kazuhiko , Ito Katsutoshi , Harino Hiroya , Onduka Toshimitsu , Kakuno Akira , Fujii Kazunori 
Published: January 2008

Abstract
We used a teleost fish, the mummichog (Fundulus heteroclitus), to conduct early life-stage toxicity testing for copper pyrithione (CuPT). Fertilized mummichog eggs were exposed to CuPT at various concentrations for 50 d under continuous flow-through conditions. Hatchability, survival, growth, and morphologic abnormalities were measured. Hatchability did not differ significantly between any experimental group and control groups. Survival and growth were significantly reduced at 50 d in the groups exposed to 2 or 4 μg/L CuPT. During the test, morphologic abnormalities, such as vertebral deformity and formation of inflammatory masses in the lateral muscles, occurred in fish exposed to CuPT. Light and electron microscopic studies indicated that muscle dysfunction played a role in the vertebral deformity and revealed that the inflammatory mass was composed mainly of macrophages and necrotic myocytes. We consider that macrophages infiltrated and phagocytized necrotic cells, thus forming the inflammatory mass. In addition, acetylcholinesterase activity was markedly decreased in the 2- and 4-μg/L exposure groups, suggesting the skeletal deformity was due to mechanisms similar to those proposed for organophosphorous pesticide exposure.
Effects of dietary selenium on reproduction and body mass of captive lesser scaup
Authors: DeVink Jean-Michel A , Clark Robert G , Slattery Stuart M , Scheuhammer Tony M 
Published: January 2008

Abstract
The continental population of scaup has declined over the last three decades to levels that remain well below conservation goals. One proposed hypothesis for this decline is that increasing exposure to contaminants has led to decreased fitness in scaup, and selenium (Se) has been identified as a contaminant of concern. We conducted an experiment with captive scaup to simulate late spring migration exposure to environmentally relevant doses of dietary Se (control [&lt;1 μg/g total Se], and 7.5 μg/g and 15 μg/g Se as selenomethionine) for 30 d, after which excess Se was removed from the diets prior to laying. Overall, we found no treatment effect on body mass, breeding probability, or clutch initiation dates. Egg Se concentrations of the 15 μg/g and 7.5 μg/g groups decreased rapidly after Se-supplemented diets were removed and within 12 and 8 d post treatment, respectively, were below the suggested egg teratogenicity threshold of 9 μg/g (dry wt). We found no significant intraclutch variation in egg Se deposition. Blood Se concentrations differed between groups in proportion to dose, with a half-life of 16 and 22 d for females when removed from the 15 and 7.5 μg/g treatments, respectively. Our findings suggest that exposure to dietary Se concentrations representative of spring-staging environments is insufficient to adversely affect body mass or reproduction in scaup that subsequently migrate to uncontaminated breeding areas (e.g., in prairie-parklands and boreal forest). Further studies of Se effects on scaup should focus on wintering birds in contaminated habitats.
Intercalibration exercise using a stickleback endocrine disrupter screening assay
Authors: Allen Yvonne T , Katsiadaki Ioanna , Pottinger Tom G , Jolly Cecile , Matthiessen Peter , Mayer Ian , Smith Andy , Scott Alexander P , Eccles Paul , Sanders Matthew B , Pulman Kim G.T , Feist Stephen 
Published: January 2008

AbstractThe Organisation for Economic Cooperation and Development (OECD) is currently validating a short-term fish screening protocol for endocrine disrupters (estrogens, androgens, and their antagonists and aromatase inhibitors), using three core species: fathead minnow, Japanese medaka, and zebrafish. The main endpoints proposed for the first phase of validation of the screen are vitellogenin (VTG) concentration, gross morphology (secondary sexual characteristics and gonado-somatic index), and gonadal histopathology. A similar protocol is concurrently being developed in the United Kingdom using the three-spined stickleback, with identical endpoints to those for the core species and, in addition, a unique androgen-specific endpoint in the form of spiggin (glue protein) induction. To assess the suitability of this species for inclusion in the OECD protocol alongside the core species, an intercalibration was conducted using 17β-estradiol (a natural estrogen) and trenbolone (a synthetic androgen), thus mimicking a previous intercalibration with the core species. All three participating laboratories detected statistically significant increases in VTG in males after 14 d exposure to nominal concentrations of 100 ng/L 17β-estradiol and statistically significant increases in spiggin in females after 14 d exposure to nominal concentrations of 5,000 ng/L trenbolone. The stickleback screen is reliable, possessing both relevant and reproducible endpoints for the detection of potent estrogens and androgens. Further work is underway to assess the relevance and suitability of the screen for weakly acting estrogens, anti-androgens, and aromatase inhibitors.
Comparison of pesticide concentrations in streams at low flow in six metropolitan areas of the United States
Authors: Sprague Lori A , Nowell Lisa H 
Published: January 2008

Abstract
To examine the effect of urban development on pesticide concentrations in streams under low-flow conditions, water samples were collected at stream sites along an urban land use gradient in six environmentally heterogeneous metropolitan areas of the United States. In all six metropolitan areas, total insecticide concentrations generally increased significantly as urban land cover in the basin increased, regardless of whether the background land cover in the basins was agricultural, forested, or shrub land. In contrast, the response of total herbicide concentrations to urbanization varied with the environmental setting. In the three metropolitan areas with predominantly forested background land cover (Raleigh–Durham, NC, USA; Atlanta, GA, USA; Portland, OR, USA), total herbicide concentrations increased significantly with increasing urban land cover. In contrast, total herbicide concentrations were not significantly related to urban land cover in the three remaining metropolitan areas, where total herbicide concentrations appeared to be strongly influenced by agricultural as well as urban sources (Milwaukee–Green Bay, WI, USA; Dallas–Fort Worth, TX, USA), or by factors not measured in the present study, such as water management (Denver, CO, USA). Pesticide concentrations rarely exceeded benchmarks for protection of aquatic life, although these low-flow concentrations are likely to be lower than at other times, such as during peak pesticide-use periods, storm events, or irrigation discharge. Normalization of pesticide concentrations by the pesticide toxicity index—an index of relative potential toxicity—for fish and cladocerans indicated that the pesticides detected at the highest concentrations (herbicides in five of the six metropolitan areas) were not necessarily the pesticides with the greatest potential to adversely affect aquatic life (typically insecticides such as carbaryl, chlorpyrifos, diazinon, and fipronil).
Changes in serum biochemical parameters of freshwater fish Oreochromis niloticus following prolonged metal (Ag, Cd, Cr, Cu, Zn) exposures
Authors: Öner Muazzez , Atli Gülüzar , Canli Mustafa 
Published: January 2008

Abstract
Fish serum may reflect status of many biochemical processes in the metabolism. Heavy metals, as environmental stressors, may alter serum biochemical parameters in fishes. Thus, freshwater fish, Oreochromis niloticus, were exposed to low levels (0.05 mg/L) of metals (silver [Ag], cadmium [Cd], copper [Cu], chromium [Cr], zinc [Zn]) to investigate responses of serum biochemical parameters over different exposure periods (0, 5, 10, 20, 30 d). Fish mortality occurred only in Ag exposure, as all fish died between days 12 to 16. Activities of alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate transaminase (AST) were altered only in Cu- and Cd-exposed fish. Both Cd and Cu exposures decreased the activity of ALP, although they increased the activities of ALT and AST. Glucose concentrations increased in Ag-, Cd-, and Cu-exposed fish, with a sharp increase occurring in Ag-exposed fish before mortality began. Total protein and triglyceride concentrations increased in Ag-exposed fish, although they decreased in Cu-exposed ones. However, all metal exposures increased cholesterol concentration in the serum. Concentration of blood urea nitrogen increased in Ag-, Cd-, and Cu-exposed fish, although it decreased in Cr-exposed ones. Calcium level decreased only in Cu-exposed fish, and Cl− level decreased in Ag-exposed fish. Silver and Cu exposures also decreased Na+ level in the serum. Cadmium and Cu exposures increased serum K+ levels. The present study, investigating the effects of environmentally realistic metal exposures on serum biochemical parameters, demonstrated that fish serum could sensitively reflect environmental metal stress. Thus, it suggests that serum biochemical parameters could be used as important and sensitive biomarkers in ecotoxicological studies concerning the effects of metal contamination and fish health.
Influence of contamination by organochlorine pesticides and polychlorinated biphenyls on the breeding of the Spanish Imperial Eagle (Aquila adalberti)
Authors: Hernández Mauro , González Luis M , Oria Javier , Sánchez Roberto , Arroyo Beatriz 
Published: January 2008

Abstract
We evaluated temporal and regional trends of organochlorine (OC) pesticide (including polychlorinated biphenyl [PCB]) levels in eggs of the Spanish Imperial Eagle (Aquila adalberti) collected in Spain between 1972 and 2003. Levels of p,p′-dichlorodiphenyldichloroethylene (DDE) and PCBs varied significantly (p = 0.022) among regions (central, western, and Doñana), being higher in Doñana than in the central and western populations (DDE: 1.64 ± 5.56, 0.816 ± 1.70, and 1.1 ± 2.66 μg/g, respectively; PCBs: 1.189 ± 5.0, 0.517 ± 1.55, and 0.578 ± 1.75 μg/g, respectively). Levels of DDE decreased with time, but a significant interaction was observed between region and time. In Doñana, egg volume and breadth as well as Ratcliffe Index were significantly lower after DDT use (p = 0.0018) than during the pre-DDT period (p = 0.0018); eggs were significantly smaller overall than in the other two regions (p = 0.04) and were smaller when DDE levels increased, even when controlling for regional differences (p = 0.04). Productivity in Doñana was significantly lower than in the other regions (p &lt; 0.001). Clutch size in Doñana varied according to DDE concentrations (p = 0.01), with the highest DDE concentrations found in clutches consisting of one egg. When considering eggs with DDE levels greater than 3.5 μg/g, a significant effect of DDE on fertility was found (p = 0.03). Clutches with DDE levels greater than 4.0 μg/g had a higher probability of hatching failure (p = 0.07) and produced fewer fledglings (p = 0.03). If we consider 3.5 μg/g as the lowest-observable-adverse-effect level, the proportion of sampled clutches that exceeded that level in Doñana (29%) was significantly higher than in other regions (p &lt; 0.001). These eggs showed a mean percentage of thinning of 16.72%. Contamination by OCs, mainly DDE, could explain, at least in part, the low productivity of the Spanish Imperial Eagles in Doñana.
Toxicity of human pharmaceuticals and personal care products to benthic invertebrates
Authors: Dussault Ève B , Balakrishnan Vimal K , Sverko Ed , Solomon Keith R , Sibley Paul K 
Published: January 2008

Abstract
Despite concerns about potential risks associated with the presence of pharmaceuticals and personal care products (PPCPs) in the environment, few toxicological data address the effects of these compounds. In aquatic systems, which often represent the final repository for PPCPs, increasing toxicological information regarding aquatic biota is improving our capacity to assess potential risks. However, responses of key biota, such as benthic invertebrates, have not been investigated as widely. In the present study, we examined the toxicity of four PPCPs—the lipid regulator atorvastatin (ATO), the antiepileptic drug carbamazepine (CBZ), the synthetic hormone 17α-ethinylestradiol (EE2), and the antimicrobial triclosan (TCS)—to the midge Chironomus tentans and the freshwater amphipod Hyalella azteca in 10-d waterborne exposures. The toxicity of the four compounds varied between 0.20 and 47.3 mg/L (median lethal concentration), with a relative toxicity ranking of TCS &gt; EE2 &gt; ATO &gt; CBZ. Hyalella azteca was more sensitive than C. tentans to these compounds. The toxicity data were used in a hazard quotient approach to evaluate the risk posed by the four PPCPs to benthic invertebrates and other aquatic organisms. For each compound, a hazard quotient was calculated by dividing the lowest toxicity value by the highest exposure value found in the literature, to which an uncertainty factor was applied. With hazard quotients of 3.55 to 11.5, we conclude that potential risks exist toward benthic invertebrates for the toxicity of TCS and CBZ and that further investigations of these compounds are required to characterize more completely the risks to benthic organisms. In contrast, our data also indicate that considering the low concentrations currently detected in the environment, ATO and EE2 pose negligible risks to benthic invertebrates.
Envisioning the Future of Veterinary Medical Education: The Association of American Veterinary Medical Colleges Foresight Project, Final Report
Authors: Willis Norman G. , Monroe Fonda A. , Potworowski J. Andre , Halbert Gary , Evans Brian R. , Smith John E. , Andrews Kenneth J. , Spring Lynelle , Bradbrook Andrea 
Published: January 2008

This report of the Association of American Veterinary Medical Colleges’ 2006 Foresight Project, developed under the leadership of an AAVMC Steering Committee, drew on the experience, imagination, and energetic participation of more than 95 participants from across the United States and Canada. The environment of veterinary medicine is one of profound change. The current number of veterinarians is inadequate to address the present and future needs of society. To remain relevant, academic veterinary medicine must prepare veterinarians for what may come in the future. In order to be recognized and remunerated for their knowledge, compassion, integrity, and judgment, veterinarians must first demonstrate their relevance to new societal trends. The objective of the study reported here was to determine a future direction for academic veterinary medicine using Foresight technology. The tools employed were challenge questions and the development of eight future possible scenarios. The study supported the need for change. This report recommends an adaptive and responsive system of veterinary medical education, achieved by defining those areas of professional focus that would address all the anticipated needs of society. An area of professional focus signifies a pathway leading to a DVM degree. Colleges would choose to offer selected areas of professional focus most appropriate to their capabilities, according to a binational plan. Veterinary medicine is integral to the well-being of any future society. This is a pivotal moment for the veterinary profession and for veterinary medical education. Leadership, collaboration, and a shared vision will determine the destiny of the profession.