bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nicotinic receptors in the dorsal and ventral hippocampus differentially modulate contextual fear conditioning
Authors: Kenney Justin W. , Raybuck Jonathan D. , Gould Thomas J. 
Published: January 2012

AbstractNicotine administration alters various forms of hippocampus‐dependent learning and memory. Increasing work has found that the dorsal and ventral hippocampus differentially contribute to multiple behaviors. Thus, the present study examined whether the effects of nicotine in the dorsal and ventral hippocampus have distinct influences on contextual fear learning in male C57BL/6J mice. Direct infusion of nicotine into the dorsal hippocampus resulted in an enhancement of contextual fear learning, whereas nicotine infused into the ventral hippocampus resulted in deficits. Nicotine infusions into the ventral hippocampus did not alter hippocampus‐independent cued fear conditioning or time spent in the open arm of the elevated plus maze, a measure of anxiety, suggesting that the effects are due to alterations in contextual learning and not other general processes. Finally, results from using direct infusions of MLA, a low‐affinity α7 nicotinic acetylcholine receptor (nAChR) antagonist, in conjunction with systemic nicotine, provide evidence that α7‐nAChRs in the ventral hippocampus mediate the detrimental effect of ventral hippocampal nicotine on contextual fear learning. These results suggest that with systemic nicotine administration, competition exists between the dorsal and ventral hippocampus for behavioral control over contextual learning. © 2012 Wiley Periodicals, Inc.
Improvement of the Noah land surface model for warm season processes: evaluation of water and energy flux simulation
Authors: Wei Helin , Xia Youlong , Mitchell Kenneth E. , Ek Michael B. 
Published: January 2012

AbstractThe Noah model is a land surface model of the National Centers for Environmental Prediction. It has been widely used in regional coupled weather and climate models (i.e. Weather Research and Forecasting Model, Eta Mesoscale Model) and global coupled weather and climate models (i.e. National Centers for Environmental Prediction Global Forecast System, Climate Forecast System). Therefore, its continued improvement and development are keys to enhancing our weather and climate forecast ability and water and energy flux simulation accuracy. North American Land Data Assimilation System phase 1 (NLDAS‐1) experiments indicated that the Noah model exhibited substantial bias in latent heat flux, total runoff and land skin temperature during the warm season, and such bias can significantly affect coupled weather and climate models. This paper presents a study to improve the Noah model by adding model parameterization processes such as including seasonal factor on leaf area index and root distribution and selecting optimal model parameters. We compared simulated latent heat flux, mean annual runoff and land skin temperature from the Noah control and test versions with measured latent heat flux, land surface skin temperature, mean annual runoff and satellite‐retrieved land surface skin temperature. The results show that the test version significantly reduces biases in latent heat, total runoff and land skin temperature simulation. The test version has been used for the NLDAS phase 2 (NLDAS‐2) to produce 30‐year water flux, energy flux and state variable products to support the US drought monitor of National Integrated Drought Information System. Copyright © 2012 John Wiley & Sons, Ltd.
Nine‐month‐olds' triangular interactive strategies with their parents' couple in low‐coordination families: A descriptive study
Authors: Fivaz‐Depeursinge E. , Cairo S. , Scaiola C. Lavanchy , Favez N. 
Published: January 2012

AbstractObserving infants in triadic situations has revealed their triangular competence; namely, their ability to interact with both parents by simultaneously sharing their attention and affects with them. Infants' triangular interaction is linked with the coparenting unit's degree of coordination; in high‐coordination (HC) families, parents act as a team in relation to the child, thus drawing clear and flexible boundaries with them; in low‐coordination (LC) families, parents either avoid direct interaction with each other and include the child in their unit or join together against the child and exclude him or her, thus drawing inconsistent boundaries with the child. We explored the interactive strategies of LC 9‐month‐olds (n = 15) with those of their parents, comparing them with HC parents (n = 23) in two conditions: playing with both parents at the same time and witnessing their parents' dialogue. LC infants' affects were less positive; they addressed fewer positive triangular bids to their parents and tended to use a less triangular interactive mode. Thus, LC infants had fewer opportunities than did HC infants to acquire skills necessary for coping with triangular interaction.
Development of parenting self‐efficacy in mothers of infants with high negative emotionality
Authors: Troutman Beth , Moran Tracy E. , Arndt Stephan , Johnson Ralph F. , Chmielewski Michael 
Published: January 2012

AbstractMaternal parenting self‐efficacy (PSE) is a potential target for infant mental health interventions because it is associated with a number of positive outcomes for children and mothers. Understanding the development of maternal PSE under conditions of increased parenting stress, such as parenting an infant who is easily distressed and difficult to soothe, will contribute to providing more effective interventions. This study examines the development of maternal PSE in mothers of infants with high negative emotionality (NE). The Neonatal Behavioral Assessment Scale (NBAS; T. Brazelton, 1973) was administered twice to 111 infants to select a sample of irritable (n = 24) and nonirritable (n = 29) infants for a prospective study comparing the development of PSE in mothers of infants differing in neonatal NE. Consistent with our hypotheses and previous research, at 8 weeks' postpartum, mothers of irritable infants have significantly lower domain‐specific PSE than do mothers of nonirritable infants. Contrary to our predictions, mothers of irritable infants exhibit a significant increase in domain‐specific and domain‐general PSE from 8 to 16 weeks' postpartum. The implications of these results for infant mental health screening, infant mental health interventions, and research on self‐efficacy theory are discussed.
Inter‐relationships between different classes of chemical allergens
Authors: Dearman R. J. , Basketter D. A. , Kimber I 
Published: January 2012

ABSTRACTAlthough allergic sensitization of the respiratory tract induced by chemicals is not as common as skin sensitization, it is nevertheless an important occupational health issue. Respiratory allergy to chemicals, characterized typically by rhinitis and asthma, is associated with considerable morbidity and with related socioeconomic costs. Several experimental approaches have been proposed for the prospective identification of chemical respiratory allergens, but none of these has yet been validated formally. In the absence of a widely accepted method for respiratory allergen identification, it is appropriate and relevant to explore their relationship with skin‐sensitizing chemicals. A series of chemicals known to cause immune‐mediated respiratory allergy in humans has been examined. The majority of the respiratory allergens tested were found to elicit positive responses in one or more standard tests used for the identification of skin‐sensitizing potential (guinea pig maximization test, the Buehler test and/or the local lymph node assay). We suggest that this observation might form the basis of a potentially useful paradigm for initial characterization of the respiratory‐sensitizing potential of chemicals. Specifically, chemicals that fail to elicit positive responses in accepted skin‐sensitization test methods might also be regarded as lacking the inherent potential to cause allergic sensitization of the respiratory tract. Copyright © 2012 John Wiley & Sons, Ltd.
Protective effects of emodin against cisplatin‐induced oxidative stress in cultured human kidney (HEK 293) cells
Authors: Waly Mostafa I. , Ali Badreldin H. , Al‐Lawati Intisar , Nemmar Abderrahim 
Published: January 2012

ABSTRACTEmodin (a rhubarb anthraquinone) has strong antioxidant and anticancer actions, and recent studies indicated that it reduces cellular oxidative stress induced by various insults and drugs. Cisplatin is an anticancer drug that is associated with nephrotoxicity and induces oxidative stress in cultured human kidney (HEK 293) cells. This study aimed to assess the in‐vitro antioxidant properties of the emodin against cisplatin‐induced oxidative stress in HEK 293 cells. Our study revealed that emodin acted as a potent free radical scavenger and provided nephroprotection against cisplatin‐induced oxidative stress. Emodin as low as 0.5 µm did not decrease cell viability and restored the cisplatin‐induced glutathione depletion and total antioxidant capacity in a dose‐dependent manner. Emodin augmented the cisplatin‐induced inhibition of antioxidant enzymes (catalase, glutathione peroxidase, glutathione S‐transferase, glutathione reductase and superoxide dismutase). These results suggest that emodin has the potential to be used as an adjunct therapeutic agent in patients receiving cisplatin treatment. Copyright © 2012 John Wiley & Sons, Ltd.
Mass spectrometric detection of CYP450 adducts following oxidative desulfuration of methyl parathion
Authors: Kyle Patrick B. , Smith Stanley V. , Baker Rodney C. , Kramer Robert E. 
Published: January 2012

ABSTRACTCytochrome P450 (CYP)‐mediated desulfuration of methyl parathion results in mechanism‐based inhibition of the enzyme. Although previous data suggest that reactive sulfur is released and binds to the apoprotein, the identities of neither the adduct(s) nor the affected amino acid(s) have been clearly determined. In this study, nanospray tandem mass spectroscopy was used to analyze peptide digests of CYP resolved by SDS–PAGE from liver microsomes of male rats following incubation in the absence or presence of methyl parathion. Oxidative desulfuration was confirmed by measurement of methyl paraoxon, and inhibition of specific CYP isozymes was determined by measurement of testosterone hydroxylation. Total CYP content was quantified spectrophotometrically. Incubation of microsomes with methyl parathion decreased CYP content by 58%. This effect was not associated with a comparable increase in absorbance at 420 nm, suggesting the displacement of heme from the apoprotein. Rates of testosterone 2β‐ and 6β‐hydroxylation, respectively, were reduced to 8 and 2%, implicating CYP3A and CYP2C11 in the oxidative desulfuration of methyl parathion. Mass spectrometric analysis identified 96 amu adducts to cysteines 64 and 378 of CYP3A1. In addition, a peptide containing cysteine 433 that coordinates with heme was possibly modified as it was detected in control, but not methyl parathion samples. A comparison of rat CYP3A1 with human CYP3A4 suggests that cysteines 64 and 378 reside along the substrate channel, remote from the active site. Alteration of these residues might modulate substrate entry to the binding pocket of the enzyme. Copyright © 2012 John Wiley & Sons, Ltd.
Multi‐walled carbon nanotubes induce cytotoxicity and genotoxicity in human lung epithelial cells
Authors: Cavallo Delia , Fanizza Carla , Ursini Cinzia Lucia , Casciardi Stefano , Paba Emilia , Ciervo Aureliano , Fresegna Anna Maria , Maiello Raffaele , Marcelloni Anna Maria , Buresti Giuliana , Tombolini Francesca , Bellucci Stefano , Iavicoli Sergio 
Published: January 2012

ABSTRACTThe increasing use of nanomaterials in consumer products highlights the importance of understanding their potential toxic effects. We evaluated cytotoxic and genotoxic/oxidative effects induced by commercial multi‐walled carbon nanotubes (MWCNTs) on human lung epithelial (A549) cells treated with 5, 10, 40 and 100 µg ml−1 for different exposure times. Scanning electron microscopy (SEM) analysis, MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide] and lactate dehydrogenase (LDH) assays were performed to evaluate cytotoxicity. Fpg‐modified comet assay was used to evaluate direct‐oxidative DNA damage. LDH leakage was detected after 2, 4 and 24 h of exposure and viability reduction was revealed after 24 h. SEM analysis, performed after 4 and 24 h exposure, showed cell surface changes such as lower microvilli density, microvilli structure modifications and the presence of holes in plasma membrane. We found an induction of direct DNA damage after each exposure time and at all concentrations, statistically significant at 10 and 40 µg ml−1 after 2 h, at 5, 10, 100 µg ml−1 after 4 h and at 10 µg ml−1 after 24 h exposure. However, oxidative DNA damage was not found. The results showed an induction of early cytotoxic effects such as loss of membrane integrity, surface morphological changes and MWCNT agglomerate entrance at all concentrations. We also demonstrated the ability of MWCNTs to induce early genotoxicity. This study emphasizes the suitability of our approach to evaluating simultaneously the early response of the cell membrane and DNA to different MWCNT concentrations and exposure times in cells of target organ. The findings contribute to elucidation of the mechanism by which MWCNTs cause toxic effects in an in vitro experimental model. Copyright © 2012 John Wiley & Sons, Ltd.
Tracking of nanoscale structural variations on a single amyloid fibril with tip‐enhanced Raman scattering
Authors: Deckert‐Gaudig Tanja , Kämmer Evelyn , Deckert Volker 
Published: January 2012

AbstractAmyloid fibrils are known to be responsible for diseases such as Alzheimer's disease. A detailed insight into the structure of amyloid fibrils is fundamental since it is not yet understood what triggers the misfolding of proteins to the fiber like structures. The molecular structure of fibril surfaces on a single amino acid level has not been revealed so far but would present a valuable contribution to this question. Here we demonstrate the direct molecular distinction of selected amino acids on insulin fibril surfaces with a lateral resolution better than 2 nm by applying tip‐enhanced Raman spectroscopy (TERS). This approach provides simultaneously a way to directly reveal conformational changes in the secondary structure, namely α‐helix, β‐sheet, on the fibril surface with nanometer resolution. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Human umbilical cord wharton's jelly stem cell (hWJSC) extracts inhibit cancer cell growth in vitro
Authors: Gauthaman Kalamegam , Yee Fong Chui , Cheyyatraivendran Suganya , Biswas Arijit , Choolani Mahesh , Bongso Ariff 
Published: January 2012

AbstractUmbilical cord mesenchymal stem cells (MSCs) have been shown to inhibit breast cancer cell growth but it is not known whether this effect is specific to only breast cancer cells. We compared the effects of human Wharton's jelly stem cell (hWJSC) extracts [conditioned medium (hWJSC‐CM) and cell lysate (hWJSC‐CL)] on breast adenocarcinoma (MDA‐MB‐231), ovarian carcinoma (TOV‐112D), and osteosarcoma (MG‐63) cells. The cells were treated with either hWJSC‐CM (50%) or hWJSC‐CL (15 µg/ml) for 48–72 h and changes in cell morphology, proliferation, cycle, gene expression, migration, and cell death studied. All three cancer cell lines showed cell shrinkage, blebbing, and vacuolations with hWJSC‐CL and hWJSC‐CM compared to controls. MTT and BrdU assays showed inhibition of cell growth by 2–6% and 30–60%, while Transwell migration assay showed inhibition by 20–26% and 31–46% for hWJSC‐CM and hWJSC‐CL, respectively, for all three cancer cell lines. Cell cycle assays showed increases in sub‐G1 and G2/M phases for all three cancer cell lines suggestive of apoptosis and metaphase arrest. AnnexinV‐FITC and TUNEL positive cells seen in TOV‐112D and MDA‐MB‐231 suggested that inhibition was via apoptosis while the presence of anti‐BECLIN1 and anti‐LC3B antibodies seen with MG‐63 indicated autophagy. Upregulation of pro‐apoptotic BAX and downregulation of anti‐apoptotic BCL2 and SURVIVIN genes were observed in all three cancer cell lines and additionally the autophagy genes (ATG5, ATG7, and BECLIN1) were upregulated in MG‐63 cells. hWJSCs possess tumor inhibitory properties that are not specific to breast cancer cells alone and these effects are mediated via agents in its extracts. J. Cell. Biochem. 113: 2027–2039, 2012. © 2012 Wiley Periodicals, Inc.
Sphingosine‐1‐phosphate is a mediator of TNF‐α action on the Na+/K+ ATPase in HepG2 cells
Authors: Dakroub Zeina , Kreydiyyeh Sawsan Ibrahim 
Published: January 2012

AbstractWe showed previously that TNF‐α down‐regulates the Na+/K+ ATPase in HepG2 cells. This work was undertaken to study the role of ceramide and its metabolites in TNF‐α action. Treating HepG2 cells with the cytokine in presence of an inhibitor of sphingomyelinase, abrogated the effect of TNF‐α on the ATPase. To confirm the involvement of ceramide or its metabolites, cells were incubated with exogenous ceramide. Ceramide reduced time‐dependently the activity of the ATPase and its effect disappeared in presence of CAY 10466 or SHKI, respective inhibitors of ceramidase and spingosine kinase, suggesting that ceramide acts via sphingosine or sphingosine‐1‐phosphate (S1P). However, HepG2 cells treated with exogenous sphingosine showed a higher Na+/K+ ATPase activity inferring that S1P is the one responsible for the down‐regulatory effect of TNF‐α and ceramide. This hypothesis was confirmed by the observed inhibitory effect of exogenous S1P on the pump, which was maintained when JNK and NF‐κB were inhibited separately or simultaneously. The concurrent, but not individual inhibition of the kinase and transcription factor in the absence of S1P imitated the effect of S1P. It was concluded that S1P down‐regulates the ATPase by inhibiting both JNK and NF‐κB. This conclusion was supported by the observed decrease in the phosphorylation of c‐jun and the enhanced protein expression of IκB and lower NK‐KB activity. J. Cell. Biochem. 113: 2077–2085, 2012. © 2012 Wiley Periodicals, Inc.
Transesterification of Soybean Oil Catalyzed by Calcium Hydroxide which Obtained from Hydrolysis Reaction of Calcium Carbide
Authors: Chen Ming‐Yi , Wang Jian‐Xun , Chen Kung‐Tung , Wen Bi‐Zhou , Lin Wei‐Chieh , Chen Chiing‐Chang 
Published: January 2012

AbstractCalcium carbide residue (CCR) was investigated in transesterification reaction of triglycerides to determine its viability as a solid catalyst for biodiesel synthesis. Literature survey showed that CCR has never been studied as a solid catalyst in the transesterification of triglyceride. The scope of the study includes the effects of CCR calcination temperature, calcination time, the alcohol/oil molar ratio, the catalyst amount (wt % of oil) and the reaction time. The relationship between chemical composition and catalytic activity of waste cement was also investigated. These CCR catalysts, thermally activated at 600 °C, can give rise to fatty acid methyl esters (FAME) purity higher than 99.5%, after 3 h of reaction, when oil/methanol molar ratio of 1/12 and 1 wt % of the catalyst were employed. Application of CCR as catalyst for biodiesel production in this study may not only provide a cost‐effective and environment friendly way of recycling CCR waste but also reduce hopefully the cost of biodiesel production.
Direct Determination of Azathioprine in Human Fluids and Pharmaceutical Formulation Using Flow Injection Chemiluminescence Analysis
Authors: Wang Jianbo , Zhao Pan , Han Suqin 
Published: January 2012

AbstractA simple, sensitive and inexpensive flow injection chemiluminescence method for the determination of azathioprine had been discovered. It was based on the fact that the weak chemiluminescent reaction of cerium(IV) with azathioprine in acidic medium, which was enhanced by the addition of rhodamine 6G. A lot of optimized experimental conditions had been studied in detail. The CL intensity was linearly related to the concentration of azathioprine in the range of 0.1–10.0 μM and the detection limit was 45.0 nM (3σ). The relative standard deviation (RSD) for the technique was 2.1% (n = 11). The method had high selectivity, sensitivity and good repeatability. The proposed method had been triumphantly applied to the determination of azathioprine in human fluids and pharmaceutical formulation with satisfactory results.
Pyrazinium Di(hydrogen sulfate) as a Novel, Highly Efficient and Homogeneous Catalyst for the Condensation of Enolizable Ketones with Aldehydes, Acetonitrile and Acetyl Chloride
Authors: Khazaei Ardeshir , Zolfigol Mohammad Ali , Mokhlesi Mohammad , Zare Abdolkarim , Derakhshan‐Panah Fatemeh , Merajoddin Maria , Keypour Hassan , Dehghani‐Firouzabadi Ahmad Ali 
Published: January 2012

AbstractA highly efficient protocol for the synthesis of β‐acetamido ketone or ester derivatives in the presence of pyrazinium di(hydrogen sulfate) {Py(OSO3H)2} as a novel, green and homogeneous solid acid catalyst at room temperature is described. One‐pot multi‐component condensation of enolizable ketones or alkyl acetoacetates with aldehydes, acetonitrile and acetyl chloride affords the title compounds in high to excellent yields and in relatively short reaction times. In this work, the efficiency of our recently reported solid acid catalyst, saccharin sulfonic acid (Sa‐SO3H), in the synthesis of β‐acetamido ketones/esters is also studied. Moreover, in this research, some new β‐acetamido ketones and esters (i.e. one complex structure) are prepared.
1,3‐Dibromo 5,5‐Dimethylhydantoin (DBH) Catalyzed, Microwave‐assisted Rapid Synthesis of 1‐Amidoalkyl‐2‐naphthols
Authors: Habibzadeha Setareh , Ghasemnejad‐bosra Hassan 
Published: January 2012

AbstractAn expeditious synthesis of 1‐amidoalkyl‐2‐naphthols by the condensation of 2‐naphthole with various araldehydes and acetamide is described. This greener protocol is catalyzed by 1,3‐dibromo 5,5‐dimethylhydantoin (DBH), and proceeds efficiently in the absence of any organic solvent under thermal condition and microwave irradiation in high.
A Powder Based Polyaniline Carbon Paste Electrode for Urea Analysis
Authors: Shu Hun‐Chi , Lu Shu‐Pe 
Published: January 2012

AbstractA new polyaniline carbon paste electrode prepared by mixing polyaniline (emeraldine), nafion, graphite powder and urease for urea analysis was exploited. The ratio of polyaniline, nafion, urease and graphite for the construction of the electrodes and the optimal conditions for urea determination were studied. The detection limit of this sensor for urea is 5 μM and the linearity from 5 μM to 7.5 mM is obtained in FIA. This sensor has a response time of 90s and shows good reproducibility and stability (RSD, 6.3%, n = 43). The blood samples from a patient during blood dialysis were taken and analyzed. The urea concentrations in blood obtained from this sensor are comparable with urea test kit method.