bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tributyltin sorption to marine sedimentary black carbon and to amended activated carbon
Authors: Brändli Rahel C. , Breedveld Gijsbert D. , Cornelissen Gerard 
Published: October 2008

Abstract
Under marine conditions, tributyltin (TBT) is speciated mainly as an uncharged hydroxyl complex (TBTOH) that is expected to have a similar fate to hydrophobic organic contaminants. Earlier studies indicated that for the later compounds, sorption to black carbon (BC) can be more than two orders of magnitude stronger than sorption to organic carbon, notably at low and environmentally relevant concentrations. The aim of the present study was to investigate the sorption strength of spiked TBT to a sediment and its BC isolate. It was observed that carbon-normalized sorption coefficients were in the same range for the sediment total organic carbon (TOC) and for its BC (log KTOC 5.05 L/kgTOC and log KBC 5.09 L/kgBC, respectively). This indicates that TBT does not sorb as strongly to BC as other hydrophobic organic contaminants. Activated carbon (AC), a strong man-made sorbent, has the potential to be used for in situ remediation of contaminated sediments and soils, in particular for polycyclic aromatic hydrocarbons and polychlorinated biphenyls. In the present study, both granular and powdered AC were found to strongly sorb TBT under marine conditions, with a log sorption coefficient of 6.8 L/kgcarbon. Tributyl- and dibutyltin concentrations in the pore water of a natively contaminated sediment were reduced by more than 70% on addition of 2% of powdered AC, whereas granular AC did not show a similar reduction. The results indicate that powdered AC might be a feasible remediation agent for sediments contaminated by organotins.
Disposition of perfluorinated acid isomers in sprague-dawley rats; Part 1: Single dose
Authors: Benskin Jonathan P. , De Silva Amila O. , Martin Leah J. , Arsenault Gilles , McCrindle Robert , Riddell Nicole , Mabury Scott A. , Martin Jonathan W. 
Published: October 2008

Abstract
Perfluorinated acids (PFAs) and their precursors (PFA-precursors) exist in the environment as linear and multiple branched isomers. These isomers are hypothesized to have different biological properties, but no isomer-specific data are currently available. The present study is the first in a two-part project examining PFA isomer-specific uptake, tissue distribution, and elimination in a rodent model. Seven male Sprague-Dawley rats were administered a single gavage dose of approximately 500 μg/kg body weight perfluorooctane sulfonate (C8F17SO3−, PFOS), perfluorooctanoic acid (C7F15CO2H, PFOA), and perfluorononanoic acid (C8F17CO2H, PFNA) and 30 μg/kg body weight perfluorohexane sulfonate (C6F13SO3−, PFHxS). Over the subsequent 38 d, urine, feces, and tail-vein blood samples were collected intermittently, while larger blood volumes and tissues were collected on days 3 and 38 for isomer analysis by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). For all PFAs, branched isomers generally had lower blood depuration half-lives than the corresponding linear isomer. The most remarkable exception was for the PFOS isomer containing an alpha-perfluoromethyl branch (1m-PFOS), which was threefold more persistent than linear PFOS, possibly due to steric shielding of the hydrophilic sulfonate moiety. For perfluoromonomethyl-branched isomers of PFOS, a structure–property relationship was observed whereby branching toward the sulfonate end of the perfluoroalkyl chain resulted in increased half-lives. For PFHxS, PFOA, and PFOS, preferential elimination of branched isomers occurred primarily via urine, whereas for PFNA preferential elimination of the isopropyl isomer occurred via both urine and feces. Changes in the blood isomer profiles over time and their inverse correlation to isomer elimination patterns in urine, feces, or both provided unequivocal evidence of significant isomer-specific biological handling. Source assignment based on PFA isomer profiles in biota must therefore be conducted with caution, because isomer profiles are unlikely to be conserved in biological samples.
Mercury demethylation in waterbird livers: Dose–response thresholds and differences among species
Authors: Eagles-Smith Collin A. , Ackerman Joshua T. , Yee Julie , Adelsbach Terrence L. 
Published: October 2008

Abstract
We assessed methylmercury (MeHg) demethylation in the livers of adults and chicks of four waterbird species that commonly breed in San Francisco Bay: American avocets, black-necked stilts, Caspian terns, and Forster's terns. In adults (all species combined), we found strong evidence for a threshold model where MeHg demethylation occurred above a hepatic total mercury concentration threshold of 8.51 ± 0.93 μg/g dry weight, and there was a strong decline in %MeHg values as total mercury (THg) concentrations increased above 8.51 μg/g dry weight. Conversely, there was no evidence for a demethylation threshold in chicks, and we found that %MeHg values declined linearly with increasing THg concentrations. For adults, we also found taxonomic differences in the demethylation responses, with avocets and stilts showing a higher demethylation rate than that of terns when concentrations exceeded the threshold, whereas terns had a lower demethylation threshold (7.48 ± 1.48 μg/g dry wt) than that of avocets and stilts (9.91 ± 1.29 μg/g dry wt). Finally, we assessed the role of selenium (Se) in the demethylation process. Selenium concentrations were positively correlated with inorganic Hg in livers of birds above the demethylation threshold but not below. This suggests that Se may act as a binding site for demethylated Hg and may reduce the potential for secondary toxicity. Our findings indicate that waterbirds demethylate mercury in their livers if exposure exceeds a threshold value and suggest that taxonomic differences in demethylation ability may be an important factor in evaluating species-specific risk to MeHg exposure. Further, we provide strong evidence for a threshold of approximately 8.5 μg/g dry weight of THg in the liver where demethylation is initiated.
Liver microsomes and S9 from rainbow trout (Oncorhynchus mykiss): Comparison of basal-level enzyme activities with rat and determination of xenobiotic intrinsic clearance in support of bioaccumulation assessment
Authors: Han Xing , Nabb Diane L. , Yang Ching-Hui , Snajdr Suzanne I. , Mingoia Robert T. 
Published: October 2008

AbstractMetabolism plays an important role in bioaccumulation of xenobiotics in fish. The applicability of trout liver microsomes and S9 fraction in bioaccumulation assessment of xenobiotics in fish was investigated in the present study. Basal-level activities of 7-ethoxyresorufin-O-dealkylase, testosterone 6β-hydroxylase, glutathione-S-transferase, and uridine 5′-diphospho-glucuronosyl-transferase in trout liver microsomes and S9 were significantly lower than those in rat liver microsomes and S9. The in vitro–to–in vivo scaling factors, which are the values of liver microsomal and S9 protein contents per unit weight of trout liver, were determined to be 38.4 ±5.1 (mean ± standard deviation throughout) and 95.9 ±11.9 mg/g, respectively. Intrinsic clearance (CLint) values for a number of reference compounds obtained from trout liver S9 were lower than those from trout liver microsomes. After correction with the scaling factors, trout liver microsomes and S9 provided equivalent prediction of trout hepatic clearance (CLH) using the well-stirred liver model, but their CLH values were significantly lower than those obtained from freshly isolated trout hepatocytes. Consequently, trout liver microsomes and S9 showed poorer prediction of the bioconcentration factors of the reference compounds compared with trout hepatocytes. Unit conversion revealed that CLint values obtained from trout liver microsomes and S9 were 6.3 to 22.4% of those from trout hepatocytes, which explained, to a large extent, the differences in their CLH and bioconcentration factor prediction.
Oil dispersion increases the apparent bioavailability and toxicity of diesel to rainbow trout (Oncorhynchus mykiss)
Authors: Schein Allison , Scott Jason A. , Mos Lizzy , Hodson Peter V. 
Published: October 2008

AbstractDiesel is a complex mixture containing polycyclic aromatic hydrocarbons, which persist after a spill, pass readily from water into tissues, and are toxic to early life stages of fish. The bioavailability and chronic toxicity of hydrocarbons dissolved into water from floating diesel (water-accommodated fraction) and chemically dispersed diesel (chemically enhanced water-accommodated fraction) were measured by the extent of ethoxyresorufin-O-deethylase (EROD) induction in juvenile rainbow trout (Oncorhynchus mykiss) and by the severity of blue sac disease in embryos. The water-accommodated fraction of floating diesel was virtually nontoxic to embryos at nominal concentrations up to 1,000 mg/L, causing only small weight changes. Liver EROD induction in juvenile trout was only observed at the highest nominal water-accommodated fraction concentration (10,000 mg/L). Chemical dispersion increased the bioavailability and toxicity of diesel to trout by 100-fold. Diesel chemically enhanced water-accommodated fraction induced EROD activity, caused blue sac disease, and impaired development and growth of embryonic trout at nominal concentrations as low as 10 mg/L; 88% mortality occurred at 100 mg/L. However, when total hydrocarbon concentrations were measured, differences between dispersed and undispersed diesel disappeared, with a median lethal concentration of 8 mg/L of total hydrocarbons and sublethal median effective concentrations ranging from 1.3 to 6.1 mg/L. Dispersion of diesel by high-energy mechanical mixing was recently reported to cause acute lethality to juvenile trout between 40 and 200 mg/L. Therefore, dispersion of oil by any means increases the bioavailability and apparent toxicity of diesel to fish embryos without changing the toxicity of its components. Nevertheless, in an actual spill, dispersion of diesel increases the effects of oil on fish populations.
A nonlethal microsampling technique to monitor the effects of mercury on wild bird eggs
Authors: Stebbins Katherine R. , Klimstra Jon D. , Eagles-Smith Collin A. , Ackerman Joshua T. , Heinz Gary H. 
Published: October 2008

Abstract
Methylmercury is the predominant chemical form of mercury reported in the eggs of wild birds, and the embryo is the most sensitive life stage to methylmercury toxicity. Protective guidelines have been based mainly on captive-breeding studies with chickens (Gallus gallus), mallards (Anas platyrhynchos), and ring-necked pheasants (Phasianus colchicus) or on field studies where whole eggs were collected and analyzed and the effects of the mercury were measured based on the reproductive success of the remaining eggs. However, both of these methods have limitations. As an alternative, we developed a technique that involves extracting a small sample of albumen from a live egg, sealing the egg, returning the egg to its nest to be naturally incubated by the parents, and then relating the hatching success of this microsampled egg to its mercury concentration. After first developing this technique in the laboratory using chicken and mallard eggs, we selected the laughing gull (Larus atricilla) and black-necked stilt (Himantopus mexicanus) as test subjects in the field. We found that 92% of the microsampled laughing gull eggs met our reproductive endpoint of survival to the beginning of hatching compared to 100% for the paired control eggs within the same nests. Microsampled black-necked stilt eggs exhibited 100% hatching success compared to 93% for the paired control eggs. Our results indicate that microsampling is an effective tool for nonlethally sampling mercury concentrations in eggs and, as such, can be used for monitoring sensitive species, as well as for improving studies that examine the effects of mercury on avian reproduction.
Genotoxic effect of 2,4,6-trichlorophenol onP53gene in zebrafish liver
Authors: Yin Daqiang , Zhu Hankai , Hu Ping , Zhao Qingshun 
Published: October 2008

AbstractTrichlorophenol (2,4,6-trichlorophenol [TCP]), a probable human carcinogen, is widely present in the environment. Employing denaturing high-performance liquid chromatography and DNA sequencing analyses, we demonstrated that 10-d exposure of zebrafish to TCP at 5 μg/L resulted in elevated point mutations of p53 gene in the liver genome. The result suggests that TCP might be involved in carcinogenesis by inducing point mutations in the somatic genome.
In vitro study of DNA damage induced by acid orange 52 and its biodegradation derivatives
Authors: Mansour Hedi Ben , Barillier Daniel , Corroler David , Ghedira Kamel , Chekir-Ghedira Leila , Mosrati Ridha 
Published: October 2008

Abstract
Mutagenicity of acid orange 52 (AO52) and its degradation products by Pseudomonas putida mt-2 was evaluated with the use of Salmonella Typhimurium TA102 and TA104 with and without the metabolic activation system (S9). No mutagenicity was observed in the absence of S9 and in the presence of S9 for biodegradation under shaking conditions, but it increased significantly in the presence of S9 after biodegradation under static conditions. In addition, the ability of tested compounds to induce DNA damage in vitro was evaluated with the DNA strand scission assay. The toxicity generated by the pure azo dye and the corresponding azoreduction products (4-aminobenzenesulfonic acid and N,N′-dimethyl-p-phenylenediamine) were compared. We suggest that the mutagenicity mechanism of these molecules occurs through free radical generation processes. In this study, we demonstrate that P. putida mt-2 incubated under aerobic conditions undergoes catabolism that enables it to degrade AO52 completely and, especially, to detoxify the dye mixtures.
Ketanserin reduces the postischemic EEG and behavioural changes following Endothelin-1-induced occlusion of the middle cerebral artery in conscious rats
Authors: Moyanova Slavianka , Kortenska Lidia , Kirov Roumen , Itzev Dimitar , Usunoff Kamen 
Published: October 2008

Abstract
We modeled the common clinical conditions of human stroke in fully conscious rats through an occlusion of the middle cerebral artery (MCAO) by means of unilateral microinjection of Endothelin-1 (ET1) in the vicinity of the artery (EMCAO model). Since the role of serotonin (5-HT) system in the regulation of the cerebral blood flow has been known for long time and no data are available at present for the effects of 5-HT antagonists in focal ischemia models, we further tested whether a blockade of the serotonin-2A (5-HT2A) receptors by ketanserin (20 min post-ET1) would diminish the late EMCAO-induced functional and morphological changes. The long-term neurological (postural reflex) and electroencephalogram (EEG) changes in the somatosensory cortical region (S1FL) were used to assess the effects of ketanserin on the post-ischemic changes. The study was supplemented by a histopathological examination of S1FL area and striatum of both hemispheres. The EMCAO/ ketanserin-treated rats showed much smaller neurological deficits than the EMCAO rats treated with vehicle. This effect was observed on day 3 and lasted until the end of experiments-14 days after EMCAO. The depression of alpha and beta EEG frequencies found after EMCAO was significantly and earlier restored following ketanserin. Notably, there was not augmentation of the pathological slow EEG waves at day 3 post-ET1 in the EMCAO ketanserin-treated rats compared with that observed in the EMCAO vehicle-treated rats. Although there were mild morphological changes in the penumbral S1FL cortical region after EMCAO, ketanserin reduced the histopathological difference between the ipsilateral and contralateral cortical S1FL regions, but did not change the difference between striatum of both sides. Ketanserin reduced the infarct size in ipsilateral hemisphere (mainly cortex). In conclusion, the results showed that treatment with ketanserin at the early stage of stroke may reduce the consequences of ischemia by improvement of functional and morphological recovery at later stages. Ketanserin appears to be a promising candidate for mitigating the consequences of stroke.
Henoch-Schönlein purpura presenting with multiplex gastrointestinal manifestations and massive nephrotic syndrome in adulthood — a case report
Authors: Klaudia Farkas , Tamás Molnár , Ferenc Nagy , László Tiszlavicz , István Németh , Éva Kemény , Erika Varga , Tibor Wittmann 
Published: October 2008

Abstract
Henoch-Schönlein purpura (HSP) is a systemic small vessel vasculitis mainly affecting children. We report a case of a 49-year-old woman with severe gastrointestinal and renal involvement of HSP. Endoscopy revealed more characteristic findings in the terminal ileum than in the gastric antrum. Histological examinations of the biopsy samples from the ileum, antrum, skin and kidney confirmed the diagnosis of HSP. Parenteral corticosteroid therapy led to a rapid improvement of the gastrointestinal symptoms, but because of the excessive proteinuria intravenous cyclophosphamide therapy had to be introduced.
Optimizing the degree of distension and reducing discomfort in CT colonography by means of a microprocessor interface system for air insufflation
Authors: Sirakov Nikolay , Kristev Athanas , Zagorchev Plamen , Nikolov Russin , Sirakov Vladimir , Velkova Kichka 
Published: October 2008

Abstract
The patients’ discomfort during CT colonography determines which method is used and its frequency of use. The discomfort is largely associated with the colon’s insufflation with gas. A system for an automatic room-air insufflation has been developed that ensures a continuous and steady air insufflation and an increase in colonic pressure and enables a relatively fast decompression. This system provides constant pressure monitoring and can alert the operator, if necessary. The degree of discomfort was evaluated for 36 patients, who were subjected to manual and automated air insufflation. The degree of the colonic distension achieved by the two methods was compared. The data analysis showed a significantly lower level of discomfort in patients with automated air insufflation. The degree of colonic distension was evaluated by comparing the diameters of similar segments of the colon, as well as by the subjective opinion of the operator. The distension with automated air insufflation was higher than that with manual air insufflation. In some cases there was a significant difference (P<0,05). In conclusion, the results show that the automatic insufflation of air at room temperature can be used to optimize CT colonography.
Chronic pain in urological diseases: a clinical review
Authors: Prezioso Domenico , Galasso Raffaele , Iapicca Gennaro , Annunziata Emanuele , Martino Mario , Iacono Fabrizio 
Published: October 2008

Abstract
Chronic pain is the central problem in a variety of urological diseases. Pain is an unpleasant sensory and emotional experience associated with either actual or potential tissue damage, or described in terms of such damage. The aim of this research was to update knowledge about the ultrastructural, clinical, psychological and therapeutic aspects of chronic pain in urological diseases, in particular in chronic pelvic syndrome. In this paper we have revisited the most significant and discussed articles published in the last twenty five years, with particular references on the 2008 European Guidelines, searching key words (chronic pelvic pain syndrome, chronic pelvic pain, chronic prostatitis, interstitial cystitis, prostatodynia, urological disease) and data with a high level of evidence. The articles that we have analyzed show that pain is characterized by an initial tissue injury that can lead to sensitization, which is a decrease in the intensity of the stimulus needed to elicit a response by the nerve, involving the peripheral and central nervous systems. The chronic pain state is characterized by loss of inhibitory interneurons, establishment of aberrant excitatory synaptic connections and long-term potentiation of response due to changes in sensitivity of nerve synapses. Stress and hormones might also play a role in central sensitization. Pain also has a cognitive and emotional component. It is very difficult to treat, given the complex nature of the response and the interaction of physiological aspects
Genetic bottleneck among daghestan highlanders migrating to lowlands
Authors: Bulayeva Kazima , Marchani Elizabeth , Kurbatova Olga , Watkins Scott , Bulayev Oleg , Harpending Henry 
Published: October 2008

Abstract
We present results of Short tandem repeat polymorphisms (STRPs) analysis and epidemiology study of indigenous ethnic highlanders of Daghestan and of the migrants from highlands to the lowland area in 1944, in comparison with native lowlanders. Results obtained show that demographically ancient highland ethnics have achieved a relatively stable equilibrium in their native environment and are characterized by optimal level of the main viability parameters (fertility, mortality, lifespan and morbidity). Migrants from highlands to the lowlands experienced dramatically increased morbidity and mortality in 1944–1947: up to 65–70% of total migrants had suffered malaria, typhus and other new infections and about 35–37% of total migrants had died. Genetic-epidemiological study support that non-survived migrants were characterized by a higher inbreeding rate, lower heterozygosity and higher physiological sensitivity to the environmental stress. This inter-connected complex had advantage for adaptation of the highlanders to the native environment but diminished their adaptability in the new and/or changing environment. A detailed study using STRP we performed in 1995–1999 in one highland isolate of ethnic Avars of whom about 50% were moved to the lowland area. We found significant differences in genetic and demographical structures between these highland and migrant parts of the isolate: the genetic bottleneck among migrants had a great qualitative and quantitative impact on their gene pool, i.e., lost of rare native population alleles, as well as of about 1/3 of total migrants with certain genotypes. Survived migrants demonstrate shorter lifespan and higher morbidity rate that support their still ongoing genetic adaptation to the lowland environment.
Venous aneurysms — a neglected pathology
Authors: Turel Mazda , Stephen Edwin , Nayak Sukria , Agarwal Sunil 
Published: October 2008

Abstract
Venous aneurysms are not often recognised nor given importance due to the more serious and challenging nature of their arterial counterpart. They are uncommon entities that generally present as a painless swelling, can be accurately diagnosed by duplex venous scanning and are completely cured by surgical excision. We present a short report of 14 cases treated at a tertiary care centre in India over seven years from June 2001 to June 2008, to increase awareness of this easily treatable condition.