bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of the genotoxicity of river sediments from industrialized and unaffected areas using a battery of short‐term bioassays
Authors: Aouadene Assia , Di Giorgio Carole , Sarrazin Luc , Moreau Xavier , De Jong Laetitia , Garcia Fabrice , Thiery Alain , Botta Alain , De Méo Michel 
Published: March 2008

AbstractThe present investigation evaluated the capacity of the Salmonella mutagenicity test, the comet assay, and the micronucleus assay to detect and characterize the genotoxic profile of river sediments. Three stations were selected on an urban river (Bouches du Rhône, France) exposed to various sources of industrial and urban pollution (StA, StB, and StC) and one station on its tributary (StD). One station in a nonurban river was included (REF). The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined by HPLC, and the genotoxicity of the sediments was monitored by the Salmonella mutagenicity test (TA98 + S9, YG1041 ± S9), the comet assay, and the micronucleus assay on CHO cells. Chemical analysis showed that the total PAH concentrations ranged from 23 μg kg−1 dw (REF) to 1285 μg kg−1 dw (StD). All the sediments were mutagenic in the Salmonella mutagenicity test. The mutagenicity was probably induced by the presence of nitroarenes (StA, StB, StC, and StD) and aromatic amines (REF) as deduced from the mutagenicity profiles of strains YG1041 ± S9 and TA98 + S9. The comet assay revealed direct DNA lesions in REF, StA, and StB sediments and metabolization‐dependent DNA damage in StC and StD. The micronucleus assay showed an absence of clastogenicity for StA ± S9 and StC‐S9, and a significant clastogenicity ± S9 for the three other stations. The genotoxicity ranking determined by the comet assay + S9 matched the ranking of total and carcinogenic PAH concentrations, and this assay was found to be the most sensitive. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Comparative analysis of genetic toxicity of AZT and ddI antiretrovirals in somatic cells of Drosophila melanogaster
Authors: Guimarães Nilza Nascimento , de Castro Pereira Karla , de Andrade Heloísa Helena Rodrigues , Lehmann Maurício , Silva Cunha Kênya 
Published: March 2008

AbstractAntiretroviral therapies based on nucleoside reverse transcriptase inhibitors, like zidovudine (3′‐azido‐3′‐deoxythymidine; AZT) and didanosine (2′,3′‐dideoxyinosine; ddI), markedly reduce human immunodeficiency virus loads. The Somatic Mutation And Recombination Test in Drosophila melanogaster (wing SMART), in its standard version, was applied to compare AZT and ddI genetic toxicity expressed as point and chromosomal mutation as well as homologous mitotic recombination. The present findings provide evidence that the mechanistic basis underlying the genetic toxicity of these antiretrovirals is mainly related to mitotic recombination. However, a genotoxic pattern can correspondingly be discerned: AZT is able to induce recombination (∼85%) and mutation (∼15%), and ddI causes only homologous recombination (100%) in the wing SMART assay. Another point to be considered is the fact that ddI is 3.8 times less active to induce mutant clones per mg/ml unit as compared to AZT. The clinical significance of these observations has to be interpreted in the light of data obtained from long‐term toxicity in patients treated with the above mentioned agents. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Confirmation of the chromosome damaging effects of lamivudine in in vitro human peripheral blood lymphocytes
Authors: Bayram Süleyman , Topaktaş Mehmet 
Published: March 2008

AbstractThe aim of this study was to investigate genotoxic effects of lamivudine (an analogue of cytidine) using in vitro sister chromatid exchange (SCE), chromosome aberration (CA), and micronucleus (MN) tests in human peripheral lymphocytes. The cells were treated with 75, 100, 125, and 150 μg/ml concentrations of lamivudine (roughly 30–60 times higher than plasma levels achieved in patients receiving this drug) for two (24‐ and 48‐hr) treatment periods. Lamivudine induced SCEs at the highest concentration (150 μg/ml) in the 24‐hr treatment, and at 125 and 150 μg/ml in the 48‐hr treatment, when compared to the solvent control. During both treatment periods, structural chromosome aberrations were significantly increased at 100, 125, and 150 μg/ml lamivudine concentrations. However, the increases of SCEs (22%) and CAs (50%) were weak. In addition, lamivudine reduced both the proliferation index (PI) and the mitotic index (MI) significantly at all concentrations for the two treatment periods. The MI was reduced by lamivudine in a dose‐dependent manner during both the 24‐ and 48‐hr treatment periods. In contrast, the PI was reduced by lamivudine only during the 48‐hr treatment period. A weak but significant increase in MN formation was observed following lamivudine treatment at 100, 125, and 150 μg/ml for 48 hr, but no significant increase in micronuclei were observed following 24‐hr treatment. In conclusion, lamivudine has a weak genotoxic effect at elevated doses on human peripheral lymphocytes. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Oxidative DNA damage in gastric cancer: CagA status and OGG1 gene polymorphism
Authors: Farinati Fabio , Cardin Romilda , Bortolami Marina , Nitti Donato , Basso Daniela , de Bernard Marina , Cassaro Mauro , Sergio Adriana , Rugge Massimo 
Published: March 2008

AbstractOxidative DNA damage is thought to play an important part in the pathogenesis of H. pylori‐induced mucosal damage. 8‐OHdG is a sensitive marker of DNA oxidation and is repaired by a polymorphic glycosylase (OGG1) more effectively than by OGG1‐Cys326. The aims of this study were to ascertain the respective roles of H. pylori, cagA status and OGG1 polymorphism in determining 8‐OHdG levels in benign and premalignant stomach diseases and in gastric cancer (GC). The study involved 50 GC patients (for whom both neoplastic tissue and surrounding mucosa were available), 35 with intestinal metaplasia and atrophy (IMA) and 43 controls. H. pylori and cagA status were determined by histology and polymerase chain reaction for urease and cagA. 8‐OHdG was assayed using HPLC with an electrochemical detector (HPLC‐ED). The OGG1 1245C→G transversion was identified using RFLP analyses. 8‐OHdG levels were significantly higher in GC, with no differences in relation to H. pylori or cagA status. OGG1 polymorphism was documented in 34% of GC (15 Ser/Cys, 2 Cys/Cys). OGG1 1245C→G polymorphism was detected in 54% of IMA patients, but only 16% of controls (p = 0.0004) and coincided with significantly higher 8‐OHdG levels. In the multivariate analysis, 8‐OHdG levels were predicted by histotype and OGG1 status. OGG1 1245C→G polymorphism was common in both GC and IMA, but very rare in controls, and correlated more closely with 8‐OHdG levels than do H. pylori infection or cagA status. © 2008 Wiley‐Liss, Inc.
The role of maternal responsiveness in predicting infant affect during the still face paradigm with infants born very low birth weight
Authors: Erickson Sarah J. , Lowe Jean R. 
Published: March 2008

AbstractThere is limited empirical literature addressing infants' response to a standardized stressor with infants born very low birth weight (VLBW). The purpose of this study was to assess the relative strength of maternal responsiveness in predicting infant affect in response to the Still Face (SF) paradigm in a cross‐sectional cohort of ethnically diverse infants born VLBW and their mothers (N = 50; infants 6–8 months old). Infant affect and maternal responsiveness were coded in 1‐s intervals while dyads participated in the SF. In addition, perinatal medical status, developmental status, and infant temperament were assessed. Findings revealed that positive infant affect during and after the SF stressor were strongly associated with baseline infant positive affect and maternal responsiveness at the reunion episode, respectively. In contrast, when predicting negative infant affect during and after the SF stressor, prior infant negative affect was strongly and uniquely significant. Infant positive affect, negative affect, and maternal responsiveness were not significantly associated with gender, infant perinatal medical history, developmental status, or temperament. Future research is warranted to determine how these findings relate to infants' stress reactions in naturalistic settings and if relationship‐focused interventions may reverse infant negative emotionality, enhance positive emotionality, and thereby improve self‐regulation and longer term social and cognitive developmental outcomes in medically at‐risk infants.
Energy‐based prediction of amino acid‐nucleotide base recognition
Authors: Marabotti Anna , Spyrakis Francesca , Facchiano Angelo , Cozzini Pietro , Alberti Saverio , Kellogg Glen E. , Mozzarelli Andrea 
Published: March 2008

AbstractDespite decades of investigations, it is not yet clear whether there are rules dictating the specificity of the interaction between amino acids and nucleotide bases. This issue was addressed by determining, in a dataset consisting of 100 high‐resolution protein‐DNA structures, the frequency and energy of interaction between each amino acid and base, and the energetics of water‐mediated interactions. The analysis was carried out using HINT, a non‐Newtonian force field encoding both enthalpic and entropic contributions, and Rank, a geometry‐based tool for evaluating hydrogen bond interactions. A frequency‐ and energy‐based preferential interaction of Arg and Lys with G, Asp and Glu with C, and Asn and Gln with A was found. Not only favorable, but also unfavorable contacts were found to be conserved. Water‐mediated interactions strongly increase the probability of Thr‐A, Lys‐A, and Lys‐C contacts. The frequency, interaction energy, and water enhancement factors associated with each amino acid–base pair were used to predict the base triplet recognized by the helix motif in 45 zinc fingers, which represents an ideal case study for the analysis of one‐to‐one amino acid–base pair contacts. The model correctly predicted 70.4% of 135 amino acid–base pairs, and, by weighting the energetic relevance of each amino acid–base pair to the overall recognition energy, it yielded a prediction rate of 89.7%. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Stereoelectronic properties of spiroquinazolinones in differential PDE7 inhibitory activity
Authors: Daga Pankaj R. , Doerksen Robert J. 
Published: March 2008

AbstractA detailed computational study on a series of spiroquinazolinones showing phosphodiesterase 7 (PDE7) inhibitory activity was performed to understand the binding mode and the role of stereoelectronic properties in binding. Our docking studies reproduced the essential hydrogen bonding and hydrophobic interactions for inhibitors of this class of enzymes. The N1 proton of the quinazolinone scaffold was involved in H‐bonding to an amide side chain of the conserved glutamine residue in the active site. The central bicyclic ring of the molecules showed hydrophobic and π‐stacking interactions with hydrophobic and aromatic amino acid residues, respectively, present in the PDE7 active site. The docked conformations were optimized with density functional theory (DFT) and DFT electronic properties were calculated. Comparison of molecular electrostatic potential (MEP) plots of inhibitors with the active site of PDE7 suggested that the electronic distribution in the molecules is as important as steric factors for binding of the molecules to the receptor. The hydrogen bonding ability and nucleophilic nature of N1 appeared to be important for governing the interaction with PDE7. For less active inhibitors (pIC50 < 6.5), the MEP maximum at N1 of the spiroquinazolinone ring was high or low based on the electronic properties of the substituents. All the more active molecules (pIC50 > 6.5) had MEP highest at N3, not N1. Efficient binding of these inhibitors may need some rearrangement of side chains of active‐site residues, especially Asn365. This computational modeling study should aid in design of new molecules in this class with improved PDE7 inhibition. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
The PI 3‐kinase and mTOR signaling pathways are important modulators of epithelial tubule formation
Authors: Walid Shereaf , Eisen Randi , Ratcliffe Don R. , Dai Kezhi , Hussain M. Mahmood , Ojakian George K. 
Published: March 2008

AbstractUsing MDCK cells as a model system, evidence is presented demonstrating that the signaling pathways mammalian target of rapamycin (mTOR) and phosphoinositide 3‐kinase (PI 3‐kinase) play important roles in the regulation of epithelial tubule formation. Incubation of cells with collagen gel overlays induced early (4–8 h) reorganization of cells (epithelial remodeling) into three‐dimensional multicellular tubular structures over 24 h. An MDCK cell line stably expressing the PH domain of Akt, a PI 3‐kinase downstream effector, coupled to green fluorescent protein (GFP‐Akt‐PH) was used to determine the distribution of phosphatidyl inositol‐3,4,5‐P3 (PIP3), a product of PI 3‐kinase. GFP‐Akt‐PH was associated with lateral membranes in control cells. After incubation with collagen gel overlays, GFP‐Akt‐PH redistributed into the lamellipodia of migrating cells suggesting that PIP3 plays a role in epithelial remodeling. Using the small molecule inhibitor LY‐294002 that inhibits both mTOR and PI 3‐kinase, we demonstrated that kinase activity was required for epithelial remodeling, disruption of cell junctions and subsequent modulation of tubule formation. Since the mTOR signaling pathway is downstream of PI 3‐kinase, the effects of rapamycin, a specific mTOR inhibitor, on tubule formation were assessed. Rapamycin did not affect epithelial remodeling or GFP‐Akt‐PH redistribution but inhibited elongated tubule formation that occurred later (24 h) in morphogenesis. These results were further supported by using RNA interference to down‐regulate mTOR and inhibit tubule formation. Our studies demonstrate that PI 3‐kinase regulates early epithelial remodeling stages while mTOR modulates latter stages of tubule development. J. Cell. Physiol. 216: 469–479, 2008. © 2008 Wiley‐Liss, Inc.
Physiological implications of DLX homeoproteins in enamel formation
Authors: Lézot Frédéric , Thomas Bethan , Greene Scott R. , Hotton Dominique , Yuan Zhi‐An , Castaneda Beatriz , Bolaños Alba , Depew Michael , Sharpe Paul , Gibson Carolyn W. , Berdal Ariane 
Published: March 2008

AbstractTooth development is a complex process including successive stages of initiation, morphogenesis, and histogenesis. The role of the Dlx family of homeobox genes during the early stages of tooth development has been widely analyzed, while little data has been reported on their role in dental histogenesis. The expression pattern of Dlx2 has been described in the mouse incisor; an inverse linear relationship exists between the level of Dlx2 expression and enamel thickness, suggesting a role for Dlx2 in regulation of ameloblast differentiation and activity. In vitro data have revealed that DLX homeoproteins are able to regulate the expression of matrix proteins such as osteocalcin. The aim of the present study was to analyze the expression and function of Dlx genes during amelogenesis. Analysis of Dlx2/LacZ transgenic reporter mice, Dlx2 and Dlx1/Dlx2 null mutant mice, identified spatial variations in Dlx2 expression within molar tooth germs and suggests a role for Dlx2 in the organization of preameloblastic cells as a palisade in the labial region of molars. Later, during the secretory and maturation stages of amelogenesis, the expression pattern in molars was found to be similar to that described in incisors. The expression patterns of the other Dlx genes were examined in incisors and compared to Dlx2. Within the ameloblasts Dlx3 and Dlx6 are expressed constantly throughout presecretory, secretory, and maturation stages; during the secretory phase when Dlx2 is transitorily switched off, Dlx1 expression is upregulated. These data suggest a role for DLX homeoproteins in the morphological control of enamel. Sequence analysis of the amelogenin gene promoter revealed five potential responsive elements for DLX proteins that are shown to be functional for DLX2. Regulation of amelogenin in ameloblasts may be one method by which DLX homeoproteins may control enamel formation. To conclude, this study establishes supplementary functions of Dlx family members during tooth development: the participation in establishment of dental epithelial functional organization and the control of enamel morphogenesis via regulation of amelogenin expression. J. Cell. Physiol. 216: 688–697, 2008, © 2008 Wiley‐Liss, Inc.
Sonographic diagnosis of the entrapment of the flexor digitorum profundus tendon complicating a fracture of the index finger
Authors: Pandey Tarun , Al Kandari Salwa Ramadan , Al Shammari Salem Awad 
Published: March 2008

AbstractFlexor digitorum tendon entrapment is a known complication of proximal phalangeal fractures and is commonly diagnosed clinically. However, it can sometimes be subtle and may not be suspected initially. A case of proximal phalangeal fracture of the index finger complicated by entrapment of the flexor digitorum profundus tendon is presented in which the diagnosis was made based on sonographic findings subsequently confirmed by CT and later surgical findings. This case demonstrates that tendon entrapment complicating phalangeal fractures can be diagnosed using sonography. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008.
Determination of the expression of fish antifreeze protein (AFP) in 7th generation transgenic mice tissues and serum
Authors: Bagis Haydar , Tas Arzu , Kankavi Orhan 
Published: March 2008

AbstractIn this study, the presence of antifreeze protein (AFP) gene expression through successive generations in transgenic mice carrying the chimeric gene construct of the coding sequence for the AFP protein from ocean pout was investigated. AFP transgenic hemizygote mice were used for AFP gene expression. AFP genome expressions in transgenic mice were analyzed by Western blotting, and tissue location of AFP protein was shown by immunohistochemical and immunofluorescence techniques. Seventh transgenic mice from the established founders demonstrated the expression of AFP in organs such as the skin, oviduct, lung, kidney and liver tissues and serum except for the heart. Our results demonstrate successful expression of AFP gene products in several tissues and serum of transgenic mice, the association of in vivo expressed AFP protein, for the first time. These results indicate that the coding sequence for the AFP protein gene (ocean pout type III AFP gene) could be integrated and stably transcribed and expressed in the 7th generation of transgenic mice. In conclusion transgenic mouse lines would be a good model for the cryostudy of AFP and for the determination of AFP roles in several organs and tissues. J. Exp. Zool. 309A:255–261, 2008. © 2008 Wiley‐Liss, Inc.
The antioxidant effect of a diet rich in Maillard reaction products is attenuated after consumption by healthy male adolescents. In vitro and in vivo comparative study
Authors: Seiquer Isabel , Ruiz‐Roca Beatriz , Mesías Marta , Muñoz‐Hoyos Antonio , Galdó Gabriel , Ochoa Julio J , Navarro María Pilar 
Published: March 2008

AbstractBACKGROUND: Maillard reaction products (MRPs) are widely consumed as a part of the human diet. A 2 week randomised two‐period crossover trial to determine whether MRP intake affects the antioxidant defence system in male adolescents (11–14 years, n = 18) was carried out using two diets rich and poor in MRPs (brown diet, BD, and white diet, WD, respectively). Fasting blood samples were collected after the dietary intervention periods to measure oxidative status. The in vitro antioxidant activity of the diets was also assessed.RESULTS: The BD had stronger in vitro antioxidant activity to scavenge free radicals and greater ability to reduce lipid peroxidation. However, in the in vivo assay, markers of oxidative damage (serum thiobarbituric acid‐reactive substances and erythrocyte hydroperoxides) and antioxidant defence parameters (serum antioxidants and enzymatic activities of catalase, superoxide dismutase and glutathione peroxidase) were unchanged after the dietary treatments. Only treatment of biological samples with external oxidants revealed higher values of the antioxidant capacity after consumption of the MRP‐rich diet.CONCLUSION: In spite of the higher antioxidant activity of the BD shown in vitro, consumption of diets rich in MRPs does not seem to modify oxidative status in healthy male adolescents. However, a protective effect against induced oxidation was shown. Copyright © 2008 Society of Chemical Industry
Voltammetric analysis of DL‐α‐tocopherol with a paste electrode
Authors: Ly Suw Young 
Published: March 2008

AbstractBACKGROUND: A voltammetric study of vitamin E (DL‐α‐tocopherol) detection using square wave stripping and cyclic voltammetry is discussed in this paper. The working sensor was made by mixing carbon nanotube powder with DNA (double‐stranded calf thymus DNA) and mineral oil. In this electrode, the anodic peak was obtained for − 0.6 V in a 0.1 mol L−1 phosphate electrolyte solution.RESULTS: Under optimized stripping conditions, analytical linear working ranges of 0.5–4.0 µg L−1 and 40.0–160.0 µg L−1 were obtained. The RSD precision was pegged at 0.105% with seven points using an 80 µg L−1 spike. The detection limit (S/N) was found to be 0.056 µg L−1 (1.30 × 10−10 mol L−1).CONCLUSION: The developed method was found to be applicable to quality control analysis in the food, pharmaceutical and other manufacturing sectors. Copyright © 2008 Society of Chemical Industry
Analytical scale supercritical fluid fractionation and identification of single polar lipids from deoiled soybean lecithin
Authors: Yip Shiu‐Hang Henry , Ashraf‐Khorassani Mehdi , Taylor Larry T. 
Published: March 2008

AbstractThe phosphatidylcholine (PC)‐enriched fraction from soybean lecithin is of interest due to its critical role in both the pharmaceutical and industrial field. In this work, enhancement of the purity of the PC fraction along with other individual polar lipid fractions was achieved from crude soybean lecithin by using supercritical fluid extraction (SFE) with methanol‐modified SC‐CO2. Neutral lipids were first removed from the crude sample using pure CO2. Then, the effect of CO2 pressure, temperature, and modifier percentage on phospholipid (PL) fractionation from deoiled lecithin was compared with and without silica gel mixed with the lecithin. Pure fractions of phosphatidylethanolamine (PE) and PC were obtained by varying the modifier concentration of the extraction fluid at 460 atm and 40°C with silica gel added to the deoiled lecithin. Without silica gel, coextraction of PE and PC was observed. A total of six components were isolated and tentatively identified in the extract of deoiled crude soybean lecithin.
Modeling of supercritical fluid extraction of phenanthrene from clayey soil
Authors: Elektorowicz Maria , El‐Sadi Haifa , Ayadat Tahar 
Published: March 2008

AbstractThe supercritical fluid (SFC) extraction efficiency of phenanthrene from clayey soils was modeled. The model accounts for effective diffusion of the phenanthrene in the solid pores, axial dispersion in the fluid phase, and external mass transfer to the fluid phase from the particle surface. This model, involving partial differential equations, was solved using the finite difference. The model showed the relationship between diffusivity, mass transfer coefficient, and properties of porous media (clay texture). The porous media analysis was performed with a microscope and by an image analysis. The proposed model compared well with the experimental data available in the literature.