bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tumor Necrosis Factor Receptors Support Murine Hematopoietic Progenitor Function in the Early Stages of Engraftment
Authors: Pearl-Yafe Michal , Mizrahi Keren , Stein Jerry , Yolcu Esma S. , Kaplan Ofer , Shirwan Haval , Yaniv Isaac , Askenasy Nadir 
Published: May 2010

AbstractTumor necrosis factor (TNF) family receptors/ligands are important participants in hematopoietic homeostasis, in particular as essential negative expansion regulators of differentiated clones. As a prominent injury cytokine, TNF-α has been traditionally considered to suppress donor hematopoietic stem and progenitor cell function after transplantation. We monitored the involvement of TNF receptors (TNF-R) 1 and 2 in murine hematopoietic cell engraftment and their inter-relationship with Fas. Transplantation of lineage-negative (lin−) bone marrow cells (BMC) from TNF receptor-deficient mice into wild-type recipients showed defective early engraftment and loss of durable hematopoietic contribution upon recovery of host hematopoiesis. Consistently, cells deficient in TNF receptors had reduced competitive capacity as compared to wild-type progenitors. The TNF receptors were acutely upregulated in bone marrow (BM)-homed donor cells (wild-type) early after transplantation, being expressed in 60%–75% of the donor cells after 6 days. Both TNF receptors were detected in fast cycling, early differentiating progenitors, and were ubiquitously expressed in the most primitive progenitors with long-term reconstituting potential (lin−c-kit+ stem cell antigen (SCA)-1+). BM-homed donor cells were insensitive to apoptosis induced by TNF-α and Fas-ligand and their combination, despite reciprocal inductive cross talk between the TNF and Fas receptors. The engraftment supporting effect of TNF-α is attributed to stimulation of progenitors through TNF-R1, which involves activation of the caspase cascade. This stimulatory effect was not observed for TNF-R2, and this receptor did not assume redundant stimulatory function in TNFR1-deficient cells. It is concluded that TNF-α plays a tropic role early after transplantation, which is essential to successful progenitor engraftment.
Glutathione‐S‐transferase in Nereis succinea (Polychaeta) and its induction by xeno‐estrogen
Authors: Ayoola James A. O. , García‐Alonso Javier , Hardege Jörg D. 
Published: May 2010

AbstractThe need to replace or at least to reduce the use of vertebrates in toxicity tests is a timely major concern in research and industry but to date, efforts made to minimize their use are still far from complete. Increasing demands for toxicity tests put considerable pressures upon the development of future fast and efficient test methods using invertebrates. In fact, to date, few studies provide links between biochemical and cellular effects of xeno‐estrogens in aquatic invertebrates. Glutathione‐S‐transferase (GST) activity, as a biomarker of stress exposure, was measured in the population of clamworms (Nereis succinea) from Cardiff Bay. In addition, we examined the effect of single exposure to nonylphenol (NP) on this enzymatic activity. Field study results showed a relationship between the worm's size, reproductive status, and GST activity from the field population. In addition, we show a significant increase in the GST activity at 100 μg/L NP with sex‐specific responses. The xeno‐estrogens, which could affect reproduction of nereid by interfering in normal endocrinological pathways, are eliminated through GST by conjugation with glutathione. This work shows for the first time that GST activity depends on sex and stage of the clamworms and also that the xeno‐estrogen NP induces its activity. This study supports the use of this species as a bioindicator of aquatic pollution and lays the foundation to causally link toxic exposure with reproductive output. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.
A new in vitro screening bioassay for the ecotoxicological evaluation of the estrogenic responses of environmental chemicals using roach (Rutilus rutilus) liver explant culture
Authors: Gerbron Marie , Geraudie Perrine , Rotchell Jeanette , Minier Christophe 
Published: May 2010

AbstractThere is growing evidence that many chemicals released in the environment are able to disturb the normal endocrinology of organisms affecting the structure and function of their reproductive system. This has prompted the scientific community to develop appropriate testing methods to identify active compounds and elucidate mechanisms of action. Of particular interest are in vitro screening methods that can document the effects of these endocrine disrupting compounds on fish. In this study, an in vitro bioassay was developed in the roach (Rutilus rutilus) for evaluating the estrogenicity or antiestrogenicity potency of environmental pollutants by measuring vitellogenin (VTG) induction in cultured liver explants. The cell viability was assessed by the measurement of nonspecific esterase activity using a fluorescein diacetate hydrolysis assay. Results showed that explants could be cultured for 72 h without any significant loss of activity. Dose‐dependent responses have been measured with estrogenic model compounds such as 17‐β‐estradiol (E2) and 17‐α‐ethynylestradiol (EE2) or antiestrogenic compounds such as tamoxifen. Lowest observable effective concentrations were 1 nM for E2, 1 nM for EE2, and 100 nM for tamoxifen, showing a good sensitivity of the test system. Estrogenicity of butyl 4‐hydroxybenzoate, 4‐nonylphenol, and bisphenol A was tested. bisphenol A (100 μM) or butylparaben induced a twofold increase in VTG production when compared with 100 nM E2, whereas this production was only 20% with 100 μM 4‐nonylphenol. Overall, this study shows that the bioassay could provide valuable information on endocrine disrupting chemicals including metabolites and mixtures of compounds. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.
ISTA 14—in‐situ accumulation of PAHs in low‐density polyethylene membranes in sediment
Authors: Devault Damien A. , Combe Matthieu , Gourlay‐Francé Catherine 
Published: May 2010

AbstractThe use of passive samplers for the assessment of organic contaminants has been extended to solid matrixes for the past decade. Passive sampling is usually applied to sediment in laboratory experiments involving significant upheaval, whereas in‐situ experiments remain rare. In this study, low‐density polyethylene (LDPE) strips were deployed within the sediments of a small river contaminated with polycyclic aromatic hydrocarbons (PAHs). LDPE strips were deployed in the 3‐cm depth sediment layer. Over a period of 36 days, LDPE strips were regularly retrieved and accumulated PAHs in LDPE were extracted and analyzed. Accumulations of hydrophobic contaminants in LDPE directly exposed in the sediment were observed. Accumulations in LDPE were observed for moderately hydrophobic PAHs with the highest concentrations in the sediment. Low accumulations were observed for more hydrophobic compounds, despite their presence in high concentrations in the sediment. This was explained by very low exchange rates and competitive interactions with particles in the sediment. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.
Hexavalent chromium‐induced multiple biomarker responses in liver and kidney of goldfish, Carassius auratus
Authors: Velma Venkatramreddy , Tchounwou Paul B. 
Published: May 2010

AbstractHexavalent chromium [Cr (VI)] is a constituent of chromite ore. Although it is known to have several industrial and technological applications, its release into the aquatic environment as a result of chemical spill or inadequate waste discharge may hamper the health of aquatic organisms. In this study, we have investigated the effects of Cr (VI) on multiple biomarkers responses in goldfish under subchronic exposure conditions. Laboratory‐acclimatized fish were exposed to 4.25 ppm and 8.57 ppm Cr (VI) for four weeks using a continuous flow‐through system. During exposure, fish samples were collected on a weekly basis and analyzed for multiple biomarkers including catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), metallothionein (MT), and total protein in liver and kidney. Study results indicated that the CAT activity and total protein levels in Cr (VI) ‐ treated goldfish did not significantly differ (P > 0.05) from their respective controls during experimentation. However, highly significant up‐regulations (P < 0.05) of SOD, GPx, and MT expression in Cr (VI) ‐ treated goldfish were recorded at different exposure times depending on Cr (VI) concentration, test organ, and/or biomarker of interest. For example, significantly higher liver GPx levels were found at weeks 2 and 3 in the 4.25 ppm concentration, and at weeks 3 and 4 in the 8.57 ppm, while kidney GPx levels were significantly higher at weeks 1, 2 and 3 in the 4.25 ppm concentration, and at weeks 2, 3 and 4 in the 8.57 ppm concentration. In summary, Cr (VI)‐induced oxidative stress was characterized by statistically significant increases in SOD, GPx, and MT expression in goldfish tissues; with the kidney showing a relatively higher sensitivity to Cr (VI) toxicity compared with the liver. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Brominated diphenyl ether (BDE) levels in liver, adipose, and milk from adult and juvenile rats exposed by gavage to the DE‐71 technical mixture
Authors: Bondy G. S. , Gaertner D. , Cherry W. , MacLellan E. , Coady L. , Arnold D. L. , Doucet J. , Rowsell P. R. 
Published: May 2010

AbstractBrominated diphenyl ethers (BDEs) are used as flame retardants in consumer products. Rodent studies indicate that the liver, thyroid, and nervous system of developing animals are targets of BDEs. To explore the relationship between exposure and health in developing animals, BDE accumulation in adult and juvenile rats was examined in conjunction with changes in liver weight and serum thyroxine (T4). Adult (F0) rats received the commercial BDE mixture DE‐71 by gavage at doses of 0.5, 5, and 25 mg kg−1 body weight (bw)/day for 21 weeks. F0 rats were mated and exposure continued throughout breeding, pregnancy, lactation, and postweaning until the pups (F1 generation) reached postnatal day (PND) 42. Milk was collected from lactating dams. Adipose and liver samples were collected from F0 and F1 males and females for BDE congener analysis. Congener prevalence in rat tissues mimicked congener prevalence in wildlife and humans. Tissue concentrations of all congeners except BDE‐153 were lower than would be expected based on dose proportionality, confirming that BDE‐153 has a high capacity for bioaccumulation. BDEs were transferred from maternal tissues to milk during lactation. Milk congener profiles differed from maternal tissue profiles indicating that degree of bromination and maternal sequestration influenced BDE transfer to milk. Female F1 rats accumulated more BDEs than F1 males, indicating that female rats were less able to metabolize and/or excrete BDEs. Significant effects on liver weight and serum T4 levels were observed in adults and juveniles in the middle and high dose groups, corresponding to BDE levels in the μg g−1 range. Although it remains to be determined how human liver and thyroid are affected by exposure to much lower BDE levels, the present study confirmed that gender and reproductive status influence BDE accumulation in tissues and BDE transfer to the neonate via milk. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Effect of tributyltin (TBT) in the metabolic activity of TBT‐resistant and sensitive estuarine bacteria
Authors: Cruz Andreia , Oliveira Vanessa , Baptista Inês , Almeida Adelaide , Cunha Ângela , Suzuki Satoru , Mendo Sónia 
Published: May 2010

AbstractThe effect of tributyltin (TBT) on growth and metabolic activity of three estuarine bacteria with different TBT resistance profiles was investigated in an organic‐rich culture medium (TSB) and in phosphate buffered saline (PBS) buffer. Exposure to TBT was assessed by determining its effect on growth (OD600 nm measurement), bacterial productivity (leucine incorporation), viability (CFU counts), aggregation and cell size (from Live/Dead analysis), ATP and NADH concentrations. TBT exposure resulted in decrease of bacterial density, cell size, and metabolic activity. In addition, cell aggregates were observed in the TBT‐treated cultures. TBT strongly affected bacterial cell metabolism and seemed to exert an effect on its equilibrium, interfering with cell activity. Also, TBT toxicity was lower when cells were grown in TSB than in PBS, suggesting that a nutrient‐rich growth medium can protect cells from TBT toxicity. This study contributes to our understanding of the TBT‐resistant cell behavior reflected in its physiology and metabolic activity. This information is of utmost importance for further studies of TBT bioremediation. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Bioassays and biochemical biomarkers for assessing olive mill and citrus processing wastewater toxicity
Authors: Karaouzas Ioannis , Cotou Efthimia , Albanis Triantafyllos A. , Kamarianos Athanasios , Skoulikidis Nikolaos T. , Giannakou Urania 
Published: May 2010

AbstractThe toxicity and the biochemical effects of olive mill wastewater and citrus processing wastewater were evaluated using acute toxicity bioassays (Gammarus pulex and Hydropsyche peristerica) and biochemical biomarkers (acetylcholinesterase [AChE] and glutathione S‐transferase [GST]). The bioassays indicated toxic properties of olive mill and citrus processing wastewaters. The 24 h LC50 values of olive mill wastewater ranged from 2.64% to 3.36% for G. pulex and 3.62% to 3.88% for H. peristerica, while the LC50 of citrus processing wastewater was 25.26% for G. pulex and 17.16% for H. peristerica. Based on a five‐class hazard classification system applied for wastewaters discharged into the aquatic environment, olive mill wastewater and citrus processing wastewater were classified as highly toxic and toxic, respectively. Results of the biochemical biomarkers showed that both agroindustrial effluents at increasing sublethal wastewater concentrations could cause inhibition of the AChE and induction of the GST activities. These first results showed that both species as well as their AChE and GST activities have the potential to be used as indicators and biomarkers for assessing olive mill and citrus processing wastewaters quality. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2011.
Genotoxic effects in fish induced by pharmacological agents present in the sewage of some Italian water‐treatment plants
Authors: Rocco Lucia , Frenzilli Giada , Zito Giovanna , Archimandritis Aristea , Peluso Carmela , Stingo Vincenzo 
Published: May 2010

AbstractThe presence of pharmaceutical substances in the municipal effluents is currently considered the principal source of bio‐active molecule emissions into aquatic environments. This study analyzes the genotoxic damage caused by gemfibrozil and atorvastatin, two regulators of the hematic level of lipids, and sildenafil citrate, a vasodilator, on the teleost Danio rerio. The genotoxicity of these three compounds was evaluated using the comet assay, diffusion assay, and RAPD‐PCR. The alkaline version (pH 12.1) of the comet assay was used for the erythrocytes of the zebrafish to evaluate the presence of single strand DNA breaks. Furthermore, the diffusion assay was used to estimate the number of apoptotic cells. The fish were treated with the three pharmacological agents at the average concentrations previously found at some Italian treatment plants and were then sacrificed from 5 to 35 days after exposure. The data of the comet assay showed a statistically significant loss of DNA integrity after 5 days of exposure to atorvastatin and after one week of exposure to gemfibrozil. This damage was, however, repaired after 14 days. Sildenafil citrate produced, instead, a statistically significant loss of DNA integrity at the concentrations found only after 35 days of exposure. The genotoxicity at the molecular level was tested by RAPD‐PCR. The results from this investigation are in agreement with those from two other tests, confirming the efficacy of the use of the three experimental approaches for the complete evaluation of genotoxic damage. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2012.
Synthesis and Characterization of a Novel Binuclear Cobalt(II) Complex with Discrete Water Clusters (H2O)8
Authors: Gao En‐Jun , Su Meng , Zhang Min , Huang Yun , Wang Lei , Zhu Ming‐Chang , Liu Lei , Zhang Yi‐Xing , Guo Mei‐Jun , Guan Feng , Dai Lei 
Published: May 2010

AbstractA new octameric water cluster was observed in the complex Co2(dptc)(bipy)2(H2O)6·4H2O (1) (H4dptc = diphenyl‐3,3′,4,4′‐tetracarboxylic acid; bipy = 2,2′‐bipyridine), which was characterized by single‐crystal X‐ray diffraction, elemental analysis and IR spectroscopy. The centrosymmetric octamer consists of a water hexamer in the chair form and two water molecules and brings to light a novel mode of the cooperative association of water molecules. Those complex units are connected into a 2D infinite layer framework through hydrogen bonding. Consequently, the 2D layers are further aggregated by hydrogen bonding with octameric subunits and π···π stacking interactions to form a 3D supramolecular architecture.
Synthesis, Structure, and Magnetic Properties of Three Novel Sandwich‐type Tungstobismuthates with Triethanolamine
Authors: Zhang Ling , Zhang Yi , Hao Zhaomin , Luo Fang 
Published: May 2010

AbstractThree novel sandwich‐type polyoxotungstates (1–3) were synthesized in good yield using an in‐situ conventional solution synthesis method by reaction in aqueous media below 80 °C. Compounds 1–3 represent the first structurally characterized β‐B‐BiW9 sandwich‐type polyoxometalates with triethanolamine cations. All three compounds have the same building unit [(X(H2O)3)2(X0.5W0.5O)2(β‐B‐BiW9O33)2)]10– [X = MnII (1), CoII (2), NiII (3)]. The adjacent units of 1 or 2 are joined by Na+ cations in different ways to construct 1D chains or 2D sheets. A 3D supramolecular structure is further formed by hydrogen bond interactions among water molecules and protonated triethanolamine cations. Meanwhile only compound 3 shows a 0D structure. The compounds were characterized by elemental analysis, IR spectroscopy, TG analysis, and single‐crystal X‐ray diffraction. Magnetic measurements on a sample of 1 show the presence of paramagnetic interactions.
Synthetic and Structural Studies on Methyl‐, tert‐Butyl‐ and Phenylmercury(II) Azide
Authors: Klapötke Thomas M. , Krumm Burkhard , Moll Richard 
Published: May 2010

AbstractThe reaction of organomercury(II) halogenides (RHgHal, Hal = Cl, I) with silver azide furnished the corresponding covalent organomercury(II) azides RHgN3 (R = Me (1), tBu (2), Ph (3)). In addition to the characterization by multinuclear NMR spectroscopy, IR and Raman spectroscopy as well as mass spectrometry, the mercury content was determined. A dependance on the solventpolarity for the 14N NMR resonances was observed. Furthermore, X‐ray diffraction studies were performed and the crystal structures for mercury(II) azides 1–3 are reported. A comparison of the bond lengths and angles with data from theoretical calculations is given.
From the Lithium‐2‐anilide‐2‐fluoro‐1,3‐diaza‐2‐sila‐cyclopentene‐GaCl3 Adduct to 1,4,6‐Triaza‐5‐gallium‐7‐sila‐cyclo‐3‐heptene ‐ Experimental and Quantum‐chemical Results
Authors: Fischer Andreas , Stern Daniel , Thorn Andrea , Abraham Sascha , Stalke Dietmar , Klingebiel Uwe 
Published: May 2010

AbstractThe lithium salt (HC–NCMe3)2SiFNLiR (1) R = C6H3(2,6‐CHMe2)2 reacts with trichlorogallium under displacement of the lithium ion by GaCl3 to give the adduct [(HC–NCMe3)2SiFN]– [(GaCl3)R·Li(thf)4]+ (1). Compound 1 thermally loses LiCl and forms the bicyclic ring intermediates V and VI. Compound VI adds the aniline H2NC6H3(2,6‐CHMe2)2 and the unsaturated, seven‐membered ring compound –NCMe3–CH2–CH=NCMe3GaCl2–NR–SiFNHR– (2) is obtained. The addition is accompanied by an enamine‐imine‐tautomerism and proves the Lewis acid character of the silicon atom in an unknown 3‐center‐2‐electron interaction of one nitrogen atom with the silicon and gallium atoms. Quantum chemical calculations of the thermal isomerisation process and crystal structures of 1 and 2 are reported.
Formation and Stability of Gaseous WS2Cl2, WS2Br2 and WS2I2 – A Combined Experimental and Theoretical Study
Authors: Milke Edgar , Köppe Ralf , Binnewies Michael 
Published: May 2010

AbstractGaseous WS2Cl2 and WS2Br2 are formed by the reaction of solid WS2 with chlorine resp. bromine at temperatures of about 1000 K. This could be shown by mass spectrometric measurements. The heats of formation and entropies of WS2Cl2 and WS2Br2 have been determined by means of mass spectrometry (MS) and quantum chemical calculations (QC). WS2I2 could not be detected by experimental methods. This is in line with the quantum chemically determined equilibrium constant of the formation reaction. The following values are given:, ΔfH0298(WS2Cl2) = –230.8 kJ·mol–1 (MS), ΔfH0298(WS2Cl2) = –235.0 kJ·mol–1 (QC),, S0298(WS2Cl2) = 370.7 J·K–1·mol–1 (QC) and, cp0T(WS2Cl2) = 103.78 + 7.07 × 10–3 T – 0.93 × 105 T–2 – 3.25 × 10–6 T2 (298.15 K < T < 1000 K) (QC). ΔfH0298(WS2Br2) = –141.9 kJ·mol–1 (MS), ΔfH0298(WS2Br2) = –131.5 kJ·mol–1 (QC),, S0298(WS2Br2) = 393.9 J·K–1·mol–1 (QC) and, cp0T(WS2Br2) = 104.84 + 5.32 × 10–3 T – 0.75 × 105 T–2 – 2.45 × 10–6 T2 (298.15 K < T < 1000 K) (QC). ΔfH0298(WS2I2) = –18.0 kJ·mol–1 (QC), S0298(WS2I2) = 409.9 J·K–1·mol–1 (QC) and, cp0T(WS2I2) = 105.17 + 4.77 × 10–3 T – 0.67 × 105 T–2 – 2.19 × 10–6 T2 (298.15 K < T < 1000 K) (QC). These molecules have the expected C2v‐symmetry.
Ternary Transition Metal Acetylides AI2M0C2 (AI = K, Rb; M0 = Pd, Pt): Neutron Diffraction Studies and Electronic Properties
Authors: Billetter Heinrich , Wallraff Tim , Schwarz Ulrich , Smith Ronald I. , Ruschewitz Uwe 
Published: May 2010

AbstractThe crystal structures of K2PdC2, K2PtC2, and Rb2PdC2 (P$\bar3$m1, Z = 1) were refined from time‐of‐flight powder neutron diffraction data (Polaris, ISIS/RAL) at room temperature and 4.5 K. The resulting C–C distances within the C22– anion are in the range 124.4–124.7 pm (295 K). This is distinctly longer than the expected distance for a C–C triple bond (120 pm). At low temperatures slightly longer C–C distances are found (125.0–126.7 pm), which is due to an increasing wobbling of the C2 dumbbells around their center of gravity with increasing temperature. This is also reflected in the temperature dependence of the lattice parameters a and c. Lattice parameter c, which is parallel to the C2 dumbbells, decreases with increasing temperature, whereas a shows a typical positive thermal expansion. Differing to previous work ternary palladium acetylides A2PdC2 were obtained as red (A = Na) and yellow powders (A = K, Rb) by using a slightly improved synthesis. By means of diffuse reflectivity direct bandgaps were determined to 2.09 eV (A = Na), 2.55 eV (A = K), and 2.77 eV (A = Rb). This is in good agreement with direct bandgaps obtained from band structure calculations. These band structure calculations indicate very small indirect bandgaps of only a few tenth of an eV.
Three New Supramolecular Complexes Based on 2‐Propyl‐1H‐imidazole‐4,5‐dicarboxylate: Synthesis, Structures and Properties
Authors: Li Xiao‐Xu , Yue Shan‐Tang , Wang Ning , Li Zhao‐Yang , Liu Ying‐Liang 
Published: May 2010

AbstractThree new complexes, namely, [Ni(L)2·2H2O]·3H2O (1), [Co(L)2·2H2O](2)and [Co(L′)2·2H2O] (3) (L= 2‐propyl‐1H‐imidazole‐4,5‐dicarboxylate andL′= 2‐methyl‐1H‐imidazole‐4,5‐dicarboxylate), were synthesized under hydrothermal conditions. X‐ray diffraction analysis revealed that these complexes have zero‐dimensional (0D) structures, which are extended into different multi‐dimensional structures through hydrogen‐bonding interactions. Their crystal structures were further characterized by elemental analysis, IR spectroscopy, and thermogravimetric analyses. In compound3, the propyl group ofLwas transformed into a methyl group (L′) byin‐situreactions. Temperature dependent magnetic susceptibility investigations revealed antiferromagnetic interactions for compound1.