bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma and cellular markers of 3′‐azido‐3′‐dideoxythymidine (AZT) metabolism as indicators of DNA damage in cord blood mononuclear cells from infants receiving prepartum NRTIs
Authors: Meng Quanxin , Olivero Ofelia A. , Fasco Michael J. , Bellisario Ronald , Kaminsky Laurence , Pass Ken A. , Wade Nancy A. , Abrams Elaine J. , Nesel Carol J. , Ness Roberta B. , Bigbee William L. , O'Neill J. Patrick , Walker Dale M. , Poirier Miriam C. , Walker Vernon E. ,   for the Study Team
Published: March 2007

AbstractSeveral systemic and cellular markers of 3′‐azido‐3′‐dideoxythymidine (AZT) metabolism and AZT incorporation into nuclear DNA were measured in cord blood from uninfected infants born to HIV‐1‐infected mothers receiving prepartum therapies based on AZT or AZT in combination with 2′,3′‐dideoxy‐3′‐thiacytidine (3TC). In addition, the relationships among these pharmacological end points, levels of AZT‐DNA incorporation, and the previously reported mutagenic responses in these infants were evaluated. AZT‐ and 3TC‐specific radioimmunoassays (RIAs), or HPLC coupled with AZT‐RIA, were used to measure plasma levels of AZT and the AZT‐glucuronide, and cellular levels of AZT, phosphorylated AZT, and DNA incorporation of AZT or 3TC in cord blood mononuclear cells from treated infants compared with unexposed controls born to HIV‐uninfected mothers. Fewer infants had detectable AZT‐DNA incorporation levels in the group exposed to AZT (71%; n = 7) compared with those receiving AZT‐3TC (100%; n = 21), and the mean AZT‐DNA incorporation for AZT‐exposed infants (14.6 ± 6.3 AZT/106 nucleotides) was significantly lower than that in AZT‐3TC exposed infants (51.6 ± 10.2 AZT/106 nucleotides; P = 0.028). Low levels of 3TC‐DNA incorporation found in a few AZT‐3TC‐exposed newborns correlated with AZT‐DNA incorporation values in the same samples. Among the metabolites studied, there were positive correlations between levels of AZT‐diphosphate and AZT‐triphosphate, and AZT‐triphosphate and AZT‐DNA incorporation, in nucleoside analog‐exposed infants. Levels of AZT‐DNA incorporation, however, did not correlate well with the reported frequencies of somatic mutations in the same population of nucleoside analog‐treated children. While these data support the continued use of AZT‐based therapies during pregnancy, infants receiving prepartum AZT should be monitored long‐term for adverse health effects. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
Effect of self‐weight and vertical acceleration on the behaviour of tall structures during earthquake
Authors: Iyengar R. N. , Shinozuka M. 
Published: March 2007

AbstractThe effect of self‐weight and vertical ground acceleration during earthquakes on vertical cantilevers has been studied. The input is taken to be a bivariate normal random process, digitally simulated on a computer. The tip deflection, base moment and shear force have been obtained numerically for three structures of different natural frequencies. It is found that the presence of self‐weight and vertical ground excitation could alter these three quantities considerably. This leads to the conclusion that with tall structures a refined analysis, similar to the one presented here, is advisable.
Earthquake design considerations in reinforced concrete columns
Authors: Hisada Toshihiko , Ohmori Nobutsugu , Bessho Satoshi 
Published: March 2007

AbstractDamages resulting from the Tokachi‐Oki earthquake of 1968 demonstrated that many code‐designed reinforced concrete columns do not have adequate earthquake resistance. A review of Japanese research revealed that the axial force ratio, the moment arm ratio, and the type and ratio of transverse reinforcement control the resistance and ductility of concrete columns. A recent experimental study at the Kajima Institute of Construction Technology evaluated the resistance of columns with three types of transverse reinforcement and three reinforcement ratios subjected to repeated alternating loads. Tied and spiral columns proved to be superior to hooped columns.
Measurements of sonic boom responses of structures due to concorde
Authors: Webb D. R. B. 
Published: March 2007

AbstractMeasurements have been made of the responses of twelve different buildings and one cliff to the sonic booms produced during ten supersonic flights by Concorde 002 along the west coast route. Measurements were made of the levels of induced vibration and of any permanent movements of existing defects. The dynamic measurements show that, with the exception of roof structures, the vibration levels were generally similar to those produced by environmental loads. On roof structures, the sonic boom causes vibrations some two to three times those of the normal environment. The static measurements show that slow movements occur in the buildings due to temperature changes but none could be related to the sonic boom. No significant damage was observed at the monitored sites.
Desert pavement dynamics: numerical modeling and field‐based calibration
Authors: Pelletier Jon D. , Cline Michael , DeLong Stephen B. 
Published: March 2007

AbstractDesert pavements are widely used as a relative surface‐dating tool because they are progressively better developed on surfaces ranging from thousands to hundreds of thousands of years in age. Recent work, however, has highlighted the dynamic nature of pavements and undermined their use as surface‐age indicators. Quade (2001) proposed that latest Pleistocene vegetation advances destroyed all Mojave Desert pavements above 400 m elevation, making all such pavements Holocene in age. In an effort to reconcile young‐pavement evidence with their widespread use as Pleistocene surface‐age indicators, we developed a numerical model based on the classic conceptual model in which pavements co‐evolve with their underlying eolian epipedons over millennial timescales. In this co‐evolutionary process, fine‐grained eolian deposition and Av‐horizon development within the eolian epipedon promotes surface clast motion and pavement development, enhancing the eolian‐sediment‐trapping ability of the pavement in a positive feedback. Model results illustrate the multi‐scale nature of pavement dynamics: pavements may require tens of thousands of years to fully develop from a newly abandoned alluvial surface, but may heal over timescales of decades to centuries if a mature eolian epipedon is present. As such, there is no inconsistency between rapid pavement healing and a Pleistocene age for the underlying alluvial surface.To calibrate the model, we conducted surficial geologic mapping and pavement‐sedimentological analysis on two desert piedmonts. Our study areas include both proximal and distal fan environments, illustrating the role of parent‐material texture in controlling the mode of pavement formation. Using available geochronology, our work provides a rigorous calibration of pavement formation rates in our study areas and provides evidence supporting the use of pavements as local relative surface‐age indicators over Holocene to late Pleistocene timescales. Copyright © 2007 John Wiley & Sons, Ltd.
Sandstone response to salt weathering following simulated fire damage: a comparison of the effects of furnace heating and fire
Authors: McCabe S. , Smith B. J. , Warke P. A. 
Published: March 2007

AbstractFire has long been recognized as an agent of rock weathering. Our understanding of the impact of fire on stone comes either from early anecdotal evidence, or from more recent laboratory simulation studies, using furnaces to simulate the effects of fire. This paper suggests that knowledge derived from simulated heating experiments is based on the pre‐conceptions of the experiment designer – when using a furnace to simulate fire, the operator decides on the maximum temperature and the duration of the experiment. These are key factors in determining the response of the stone to fire, and if these are removed from real‐world observations then knowledge based on these simulations must be questioned.To explore the differences between heating sandstone in a furnace and a real fire, sample blocks of Peakmoor Sandstone were subjected to different stress histories in combination (lime rendering and removal, furnace heating or fire, frost and salt weathering). Block response to furnace heating and fire is discussed, with emphasis placed on the non‐uniformity of the fire and of block response to fire in contrast to the uniform response to surface heating in a furnace.Subsequent response to salt weathering (by a 10% solution of sodium chloride and magnesium sulphate) was then monitored by weight loss. Blocks that had experienced fire showed a more unpredictable response to salt weathering than those that had undergone furnace heating – spalling of corners and rapid catastrophic weight loss were evidenced in blocks that had been subjected to fire, after periods of relative quiescence. An important physical side‐effect of the fire was soot accumulation, which created a waxy, relatively impermeable layer on some blocks. This layer repelled water and hindered salt ingress, but eventually detached when salt, able to enter the substrate through more permeable areas, concentrated and crystallized behind it, resulting in rapid weight loss and accelerated decay. Copyright © 2007 John Wiley & Sons, Ltd.
Hedging under the influence of transaction costs: An empirical investigation on FTSE 100 index options
Authors: Gregoriou Andros , Healy Jerome , Ioannidis Christos 
Published: March 2007

AbstractThe Black–Scholes (BS; F. Black & M. Scholes, 1973) option pricing model, and modern parametric option pricing models in general, assume that a single unique price for the underlying instrument exists, and that it is the mid‐ (the average of the ask and the bid) price. In this article the authors consider the Financial Times and London Stock Exchange (FTSE) 100 Index Options for the time period 1992–1997. They estimate the ask and bid prices for the index, and show that, when substituted for the mid‐price in the BS formula, they provide superior option price predictors, for call and put options, respectively. This result is reinforced further when they .t a non‐parametric neural network model to market prices of liquid options. The empirical .ndings in this article suggest that the ask and bid prices of the underlying asset provide a superior fit to the mid/closing price because they include market maker's, compensation for providing liquidity in the market for constituent stocks of the FTSE 100 index. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:471–494, 2007
Long memory in commodity futures volatility: A wavelet perspective
Authors: Elder John , Jin Hyun J. 
Published: March 2007

AbstractThe authors reexamine the volatility of agricultural commodity futures for evidence of fractional integration, providing new empirical results and extending the extant literature in important dimensions. First, they utilize two relatively new estimators based on wavelets, which are generally superior to, for example, the popular estimator by J. Geweke and S. Porter‐Hudak (GPH; 1983) and exact maximum likelihood estimators (MLEs) on the basis of mean squared error (MSE). Second, they provide simulations to contrast their point estimates with those obtained by a fractionally integrated GARCH (generalized autoregressive conditional heteroscedasticity) model. Third, they conduct a wavelet coef.cient decomposition of futures volatility. They .nd that futures volatilities display the self‐similarity property consistent with long memory and that futures volatilities exhibit persistent long memory with .nite unconditional variance. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:411–437, 2007
DNA repair pathways involved in anaphase bridge formation
Authors: Acilan Ceyda , Potter Douglas M. , Saunders William S. 
Published: March 2007

AbstractCancer cells frequently exhibit gross chromosomal alterations such as translocations, deletions, or gene amplifications an important source of chromosomal instability in malignant cells. One of the better‐documented examples is the formation of anaphase bridges—chromosomes pulled in opposite directions by the spindle apparatus. Anaphase bridges are associated with DNA double strand breaks (DSBs). While the majority of DSBs are repaired correctly, to restore the original chromosome structure, incorrect fusion events also occur leading to bridging. To identify the cellular repair pathways used to form these aberrant structures, we tested a requirement for either of the two major DSB repair pathways in mammalian cells: homologous recombination (HR) and nonhomologous end joining (NHEJ). Our observations show that neither pathway is essential, but NHEJ helps prevent bridges. When NHEJ is compromised, the cell appears to use HR to repair the break, resulting in increased anaphase bridge formation. Moreover, intrinsic NHEJ activity of different cell lines appears to have a positive trend with induction of bridges from DNA damage. © 2007 Wiley‐Liss, Inc.
Genetic variation of antigen processing machinery components and association with cervical carcinoma
Authors: Mehta Akash M. , Jordanova Ekaterina S. , van Wezel Tom , Uh Hae‐Won , Corver Willem E. , Kwappenberg Kitty M. C. , Verduijn Willem , Kenter Gemma G. , van der Burg Sjoerd H. , Fleuren Gert J. 
Published: March 2007

AbstractThe antigen processing machinery (APM) plays an important role in immune recognition of virally infected and transformed cells. Defective expression of several APM components is associated with progression and clinical outcome in cervical carcinoma. Genetic variation in the genes encoding APM components is known to be associated with risk of occurrence of several malignancies. However, only limited evidence exists supporting the role of single nucleotide polymorphisms (SNPs) in APM components in cervical carcinoma. We have therefore investigated the occurrence of APM component SNP genotypes and haplotypes in cervical carcinoma. Thirteen coding SNPs in the LMP2, LMP7, TAP1, TAP2, and ERAP1 genes were genotyped in 127 cervical carcinoma patients and 124 controls. Individual genotype and allele distributions were assessed by single‐marker analysis. Effects of various SNP combinations were estimated by haplotype construction and subsequent haplotype interaction analysis. Significant haplotypes were modeled on disease risk. Allele distributions at the LMP7‐145, TAP2‐651, ERAP1‐127, and ERAP1‐730 loci differed significantly between cases and controls with the major allele at the LMP7 and TAP2 loci and the minor allele at both ERAP1 loci associated with increased cervical carcinoma risk. A combination of the two haplotypes spanning these loci was associated with a three‐fold increased risk (OR = 3.024; P << 0.001); approximately 12% of all cervical carcinoma occurrences were attributable to this combination. Our data indicate that combined genetic variation in the TAP2, LMP7, and ERAP1 genes is associated with increased cervical carcinoma risk. © 2007 Wiley‐Liss, Inc.
Measuring head and neck cancer symptom burden: The development and validation of the M. D. Anderson symptom inventory, head and neck module
Authors: Rosenthal David I. , Mendoza Tito R. , Chambers Mark S. , Asper Joshua A. , Gning Ibrahima , Kies Merrill S. , Weber Randal S. , Lewin Jan S. , Garden Adam S. , Ang K. Kian , S. Wang Xin , Cleeland Charles S. 
Published: March 2007

AbstractBackground.The aim of this study was to develop and validate a symptom inventory for patients with head and neck cancer and to assess the occurrence and severity of symptoms, the overall symptom burden, and the interference the symptoms cause in daily life.Methods.Items were generated from a comprehensive literature review, our prior work, and focus groups with head and neck cancer patients, symptom researchers, and a multidisciplinary group of head and neck cancer health care workers. We selected 11 provisional head and neck cancer‐specific items for addition to the core M. D. Anderson Symptom Inventory (MDASI), and conducted a cross‐sectional validation study among patients with head and neck cancer.Results.Construct validity was established using principal axis factoring with direct oblimin rotation, and tests of concurrent and known‐groups validity were conducted. Two items were dropped because of low severity scores and low frequency of complaint, leaving 9 final head and neck cancer‐specific items. The coefficient α reliabilities were 0.88, 0.83, and 0.92 for the 13 core MDASI items, the 9 head and neck cancer‐specific items, and the 6 interference items, respectively. The most prevalent severe symptoms were problems with mucus, mouth/throat sores, tasting food, difficulty with chewing or swallowing, dry mouth, pain, and fatigue.Conclusions.The M. D. Anderson Symptom Inventory‐Head and Neck (MDASI‐HN) is a reliable and valid instrument to measure head and neck cancer symptom burden, and the interference symptoms cause in the major aspects of a patient's daily life. A subset of specifically distressing symptoms was identified, many of which are not included in commonly used head and neck cancer quality of life instruments. © 2007 Wiley Periodicals, Inc. Head Neck 2007
Hydrology of cave drip waters at varying bedrock depths from a karst system in southeastern Australia
Authors: McDonald Janece , Drysdale Russell 
Published: March 2007

AbstractThe study of how cave drip‐water discharge responds to recharge events is fundamental to evaluating the potential of actively forming speleothems as high‐resolution climate archives. Most previous research has focused on caves of the Northern Hemisphere middle latitudes, where recharge is strongly seasonal. Few studies have explored drip‐water behaviour from regions where the expected seasonal rainfall pattern is significantly perturbed on an irregular basis by changing regional atmospheric circulation patterns. Here, we report the results of a 4‐year study of cave drip‐water–climate relationships from two caves in eastern Australia. The discharge of 10 drip sites located beneath bedrock thicknesses of 12, 22 and 45 m was monitored either continuously (using automated infrared sensors) or at discrete approximately monthly intervals and compared with local rainfall and water balance data. The study period traversed two major droughts, including the severe 2002–2003 El Niño. Drips at 12 and 22 m depths responded almost simultaneously to individual recharge events, although the time lag between individual events varied according to the volume of recharge and pre‐event storage. Overall, a steady decline in discharge is evident through the moisture‐deficit period, with increased flows through phases of positive water balance. Speleothems growing at these and similar shallow‐chamber sites have potential for reconstructing palaeo‐rainfall trends at high‐resolution, although the highly variable nature of year‐to‐year recharge would make it difficult to obtain data on a calendrical time‐scale. Drips at 45 m depth did not respond consistently to individual recharge events and displayed hydrological behaviour markedly dissimilar to one another and to the near‐surface drip sites, indicating great complexity in karst architecture and the absence of fissure flow. Although speleothems at this depth may well preserve information on longer‐term rainfall trends, their potential to encode a palaeo‐rainfall variability signal at interannual resolution is poor. Copyright © 2007 John Wiley & Sons, Ltd.
Preventive effect of rutin on lipids, lipoproteins, and ATPases in normal and isoproterenol‐induced myocardial infarction in rats
Authors: Stanely Mainzen Prince P. , Karthick M. 
Published: March 2007

AbstractThe present study was designed to evaluate the preventive role of rutin on lipids, lipoproteins, and ATPases in normal and isoproterenol (ISO)‐induced myocardial infarction in rats. Rutin (40 and 80 mg/kg) was orally administered to rats for a period of 42 days. After that period, isoproterenol (150 mg/kg) was injected subcutaneously to male wistar rats at an interval of 24 h for 2 days. The weight of heart and the concentrations of total cholesterol, triglycerides, and free fatty acids were increased significantly (p < 0.05), and the concentration of phospholipids was decreased significantly (p < 0.05) in the heart of ISO‐treated rats. ISO‐treated rats also showed a significant increase (p < 0.05) in the levels of total cholesterol, triglycerides, phospholipids, low‐density lipoprotein cholesterol (LDL‐C), and very low‐density lipoprotein cholesterol (VLDL‐C) with a significant decrease (p < 0.05) in high‐density lipoprotein cholesterol (HDL‐C) level in serum. The activities of sodium potassium dependent adenosine triphosphatase (Na+/K+ ATPase) and magnesium‐dependent adenosine triphosphatase (Mg2+ ATPase) were decreased significantly (p < 0.05), and the activity of calcium‐dependent adenosine triphosphatase (Ca2+ATPase) was increased significantly (p < 0.05) in the heart in ISO‐treated rats. Pretreatment with rutin at doses of 40 or 80 mg/kg to ISO‐treated rats showed a significant (p < 0.05) effect in all the parameters studied. Oral administration of rutin to normal rats did not show any significant effect. Thus, the results of our study show that pretreatment with rutin maintained the levels of lipids, lipoproteins, and ATPases in ISO‐induced myocardial infarcted rats. The observed effects might be due to the antioxidant potential of rutin. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:1–6, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20151
Inactivation of phospholipase A2 and metalloproteinase from Crotalus atrox venom by direct current
Authors: Panfoli Isabella , Ravera Silvia , Calzia Daniela , Dazzi Elisa , Gandolfo Simona , Pepe Isidoro M. , Morelli Alessandro 
Published: March 2007

AbstractTo achieve our aim of understanding the interactions between direct current and enzymes in solution, we exposed reconstituted Crotalus atrox venom to direct electric current by immersing two platinum thread electrodes connected to a voltage generator (between 0 and 8 V) into a reaction mixture for a few seconds. Then, we assayed the residual activity of phospholipases A2 (PLA2),metalloproteinases, and phosphodiesterases, abundant in crotaline snake venoms and relevant in the pathophysiology of envenomation, characterized by hemorrhage, pain, and tissue damage. C. atrox venom phospholipase A2 and metalloproteinases were consistently and irreversibly inactivated by direct current (between 0 and 0.7 mA) exposure. In contrast, C. atrox venom phosphodiesterases were not affected. Total protein content and temperature of the sample remained the same. Secretory pancreatic phospholipase A2, homologue to snake venom phospholipases A2, was also inactivated by direct current treatment. In order to understand the structural reasoning behind PLA2 inactivation, circular dichroism measurements were conducted on homogeneous commercial pancreatic phospholipase A2, and it was found that the enzyme undergoes structural alterations upon direct current exposure. © 2007 Wiley Periodicals, Inc. J Biochem Mol Toxicol 21:7–12, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20152