bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pharmacokinetics and Pharmacodynamics of Oral and Intravenous Cimetidine in Seriously III Patients
Authors: Sandborn William J. , Forland Steven C. , Cutler Ralph E. , Strong Richard M. 
Published: March 2013

This study was done to determine if the pharmacokinetics and gastric pH response of intravenous cimetidine are superior to oral dosing in seriously ill patients. A paired study of intravenous followed by oral liquid cimetidine was given to eight men and two women who were inpatients in a VA Hospital. Treatment was prescribed for either upper gastrointestinal (GI) bleeding or prophylaxis against GI bleeding. All patients received cimetidine 300 mg every 6 hours intravenously on day 1 and orally on day 2. After the fourth dose each day, venous blood samples and gastric pH measurements were taken serially for 6 hours. Peak serum cimetidine concentration was 2.0 ± 0.5 mg/L for the intravenous dose and 1.5 ± 0.3 mg/L for the oral dose (P = .001). Area under the curve (AUC) of cimetidine concentration was 3.81 ± 1.1 mg/hr/L for the intravenous dose and 4.19 ± 1.22 mg/hr/L for the oral dose (P > .30). Bioavailability (AUCpo/AUCiv) was 1.13 ± 0.25, demonstrating complete oral absorption. The time during a 6‐hour dosing interval that the gastric pH remained above 3.0 was 3.3 ± 2.1 hours for the intravenous dose and 2.5 ± 2.3 hours for the oral dose, P = .171). The time that the serum cimetidine concentration remained above 0.5 mg/L was 2.0 ± 0.9 hours for the intravenous dose and 2.7 ± 1.0 hours for the oral dose (P = .055).We concluded that bioavailability, time that gastric pH is maintained >3.0, and time that the serum cimetidine concentration is >0.5 mg/L for intravenous cimetidine are not significantly different from oral cimetidine in seriously ill patients.
No Pharmacokinetic or Pharmacodynamic Interaction Between Rivastatin and Warfarin
Authors: Schall Robert , Müller F. Otto , Hundt H. K. L. , Ritter W. , Duursema Linda , Groenewoud Gerhard , Middle Michelle V. 
Published: March 2013

Twenty‐one healthy, male volunteers completed this double‐blind, randomized, two‐period, crossover study to determine the possible pharmacodynamic and pharmacokinetic interaction of the concomitant administration of rivastatin and warfarin sodium in healthy volunteers. The study comprised 2 treatment periods of 8 days each, with a medication‐free period of 14 days between the 2 treatment periods.According to the randomization, the volunteers received either 300 μg of rivastatin or matching placebo once daily during the treatment periods. On day 4 of each treatment period, the volunteers also received a single oral dose of 25 mg of warfarin sodium together with rivastatin or matching placebo. The effect of rivastatin on both the pharmacokinetics and pharmacodynamics (prothrombin time and clotting factor VII activity) of warfarin sodium, and the effect of warfarin sodium on the pharmacokinetics of rivastatin were investigated. Blood sample assays included the analysis of both R‐ and S‐warfarin, because it is known that the enantiomers differ in anticoagulant potency.The study results indicate that the concomitant administration of rivastatin and warfarin does not affect the pharmacokinetics of R‐ and S‐warfarin, or the pharmacodynamics of warfarin. Furthermore, the administration of warfarin sodium does not affect the pharmacokinetics of rivastatin.
Comparative ultrastructure of the spermatozoa of three crayfish species: Austropotamobius torrentium, Pacifastacus leniusculus, and Astacus astacus (Decapoda: Astacidae)
Authors: Niksirat Hamid , Kouba Antonín , Rodina Marek , Kozák Pavel 
Published: March 2013

AbstractThis study reports about the spermatozoal ultrastructure of three species of astacid crayfish, i.e., the stone crayfish Austropotamobius torrentium, signal crayfish Pacifastacus leniusculus, and noble crayfish Astacus astacus. The acrosome is a cup shaped and electron‐dense structure at the anterior of the spermatozoon and comprises three layers of differing electron densities filled with parallel filaments that extend from the base to the apical zone. The acrosome was significantly longer in A. astacus than in P. leniusculus and the shortest acrosome belongs to A. torrentium. The width of the acrosome was significantly narrower in A. torrentium than in P. leniusculus and the widest acrosome belongs to A. astacus. The L:W ratio was significantly greater in A. torrentium than in P. leniusculus and the lowest ratio belongs to A. astacus. Radial arms are visible on each side of the acrosome or nucleus in sagittal view and wrap around the spermatozoon. Each radial arm comprises a parallel bundle of microtubules arranged along the long axis within a sheath. The nucleus, with decondensed material, is located in the posterior of the cell. All parts of the spermatozoon are tightly enclosed within an extracellular capsule. Despite a well‐conserved general structure and similarity of pattern among these spermatozoa, differences in the dimensions of the acrosome within the studied species may be useful to help distinguish the different crayfish species. J. Morphol., 2013. © 2013 Wiley Periodicals, Inc.
Soluble soy protein peptic hydrolysate stimulates adipocyte differentiation in 3T3‐L1 cells
Authors: Goto Tsuyoshi , Mori Ayaka , Nagaoka Satoshi 
Published: March 2013

ScopeThe molecular mechanisms underlying the potential health benefit effects of soybean proteins on obesity‐associated metabolic disorders have not been fully clarified. In this study, we investigated the effects of soluble soybean protein peptic hydrolysate (SPH) on adipocyte differentiation by using 3T3‐L1 murine preadipocytes.Methods and resultsThe addition of SPH increased lipid accumulation during adipocyte differentiation. SPH increased the mRNA expression levels of an adipogenic marker gene and decreased that of a preadipocyte marker gene, suggesting that SPH promotes adipocyte differentiation. SPH induced antidiabetic and antiatherogenic adiponectin mRNA expression and secretion. Moreover, SPH increased the mRNA expression levels of insulin‐responsive glucose transporter 4 and insulin‐stimulated glucose uptake. The expression levels of peroxisome proliferator‐activated receptor γ (PPARγ), a key regulator of adipocyte differentiation, during adipocyte differentiation were up‐regulated in 3T3‐L1 cells treated with SPH, and lipid accumulation during adipocyte differentiation induced by SPH was inhibited in the presence of a PPARγ antagonist. However, SPH did not exhibit PPARγ ligand activity.ConclusionThese findings indicate that SPH stimulates adipocyte differentiation, at least in part, via the up‐regulation of PPARγ expression levels. These effects of SPH might be important for the health benefit effects of soybean proteins on obesity‐associated metabolic disorders.
The drug resistance suppression induced by curcuminoids in colon cancer SW‐480 cells is mediated by reactive oxygen species‐induced disruption of the microRNA‐27a‐ZBTB10‐Sp axis
Authors: Noratto Giuliana D. , Jutooru Indira , Safe Stephen , Angel‐Morales Gabriela , Mertens‐Talcott Susanne U. 
Published: March 2013

ScopeMechanisms involving the curcuminoids effects in decreasing the prooncogenic specificity protein (Sp) transcription factors, and Sp‐regulated genes in SW‐480 colon cancer cells and how the multidrug resistance protein (MDR1) inhibition is mediated by Sp suppression.Methods and resultsHT‐29 and SW‐480 colon cancer and normal CCD‐18Co colon fibroblast cells were treated with curcuminoids previously analyzed by HPLC. Gene and protein expression regulation were assessed by RT‐PCR, transfections with expression constructs, and Western blots. Curcuminoids (2.5–10 μg/mL) suppressed preferentially the growth of SW‐480 and HT‐29 compared to CCD‐18Co cells and enhanced the anticancer activity of the chemotherapeutic drug 5‐fluorouracil due to the suppression of MDR1. Additionally, Sp1, Sp3, and Sp4 and Sp‐regulated genes were downregulated by curcuminoids in SW‐480 and this was accompanied by suppression of microRNA‐27a (miR‐27a) and induction of ZBTB10, an mRNA target of miR‐27a and a transcriptional repressor of Sp expression. This mechanism was mediated by the induction of ROS. RNA‐interference and transfection with ZBTB10‐expression plasmid demonstrated that MDR1 was regulated by Sp1 and Sp3 and the disruption of the miR‐27a‐ZBTB10‐Sp axis.ConclusionColon cancer treatment with curcuminoids will enhance the therapeutic effects of drugs in patients who have developed drug resistance.
In vivo 1HMR spectroscopic imaging of aggressive prostate cancer: Can we detect lactate?
Authors: Kobus Thiele , Wright Alan J. , Van Asten Jack J. A. , Heerschap Arend , Scheenen Tom W. J. 
Published: March 2013

PurposeA semi‐LASER sequence was optimized for in vivo lactate detection in the prostate.MethodsThe ethical committee waived the need for informed consent to measure 17 patients with high grade prostate cancer on a 3T system. A semi‐LASER sequence was used with an echo time of 144 ms and optimized interpulse timing for a spectral citrate shape with high signal intensity. An LCModel basis set was developed for fitting choline, creatine, spermine, citrate, and lactate and was used to fit all spectra in tumor‐containing voxels. For patients without detectable lactate, the minimal detectable lactate concentration was determined by adding in all spectra of tumor tissue a simulated lactate signal. The amplitude of the simulated lactate signal was iteratively decreased until its fit reached a Cramér Rao lower bound >20%, which was then set as the patient‐specific detection limit.ResultsIn none of the patients a convincing lactate signal was found. We estimated that on average the lactate levels in high grade prostate cancer are below 1.5 mM (range 0.9–3.5 mM), Interestingly, in one patient with extensive necrosis in the tumor biopsy samples (Gleason score 5+5), large lipid resonances were observed, which originated from the tumor.ConclusionThe minimal detectable lactate concentration of 1.5 mM in high grade prostate cancer indicates that if lactate is increased it remains at low concentrations. Magn Reson Med 71:26–34, 2014. © 2013 Wiley Periodicals, Inc.
Non‐invasive quantification of absolute cerebral blood volume during functional activation applicable to the whole human brain
Authors: Ciris Pelin Aksit , Qiu Maolin , Constable Robert Todd 
Published: March 2013

PurposeCerebral blood volume (CBV) changes in many diverse pathologic conditions, and in response to functional challenges along with changes in blood flow, blood oxygenation, and the cerebral metabolic rate of oxygen. The feasibility of a new method for non‐invasive quantification of absolute cerebral blood volume that can be applicable to the whole human brain was investigated.MethodsMulti‐slice data were acquired at 3 T using a novel inversion recovery echo planar imaging (IR‐EPI) pulse sequence with varying contrast weightings and an efficient rotating slice acquisition order, at rest and during visual activation. A biophysical model was used to estimate absolute cerebral blood volume at rest and during activation, and oxygenation during activation, on data from 13 normal human subjects.ResultsCerebral blood volume increased by 21.7% from 6.6 ± 0.8 mL/100 mL of brain parenchyma at rest to 8.0 ± 1.3 mL/100 mL of brain parenchyma in the occipital cortex during visual activation, with average blood oxygenation of 84 ± 2.1% during activation, comparing well with literature.ConclusionThe method is feasible, and could foster improved understanding of the fundamental physiological relationship between neuronal activity, hemodynamic changes, and metabolism underlying brain activation; complement existing methods for estimating compartmental changes; and potentially find utility in evaluating vascular health. Magn Reson Med 71:580–590, 2014. © 2013 Wiley Periodicals, Inc.
Use of a computer‐controlled motion phantom to investigate the temporal and spatial fidelity of HYPR processing
Authors: Keith Lauren , Rahimi Mahdi , Holmes James , Brittain Jean , Korosec Frank 
Published: March 2013

PurposeIn this work, we investigate the spatial and temporal fidelity of highly constrained backPRojection (HYPR) processing using a computer‐controlled motion phantom. The goal of this experimental set‐up was to provide not only well‐defined temporal dynamics and spatial characteristics of the motion phantom, but also circumstances that imitate in vivo scenarios.MethodsThe phantom was designed to represent an artery flanked on both sides by vein. Both arterial and venous components have different temporal dynamics but are confluent, which corresponds to a difficult scenario for HYPR. Spatial and temporal fidelity was investigated by measuring signal intensity profiles through the phantom both orthogonal to as well as along the direction of motion.ResultsSpatial fidelity profiles measured from the HYPR processed images yielded full‐width‐at‐half‐maximum values very similar to those measured in non‐HYPR‐processed images. Furthermore, there was no significant spreading of the motion phantom leading edge in HYPR processed images.ConclusionAlthough HYPR processing has certain characteristic artifacts that are discussed, the technique can be used to improve image quality of highly undersampled time frame images with minimal loss of spatial or temporal fidelity. Magn Reson Med 71:702–710, 2014. © 2013 Wiley Periodicals, Inc.
Improved precision in CHARMED assessment of white matter through sampling scheme optimization and model parsimony testing
Authors: De Santis S. , Assaf Y. , Evans C. J. , Jones D. K. 
Published: March 2013

PurposeThe composite hindered and restricted model of diffusion provides microstructural indices that are potentially more specific than those from diffusion tensor imaging. However, in comparison to diffusion tensor imaging, the acquisition time is longer, limiting clinical applications. Moreover, the model requires several parameters to be estimated whose confidence intervals can be large. Here, the composite hindered and restricted model of diffusion acquisition and data processing pipelines are optimized to extend the utility of this approach.MethodsA multishell sampling scheme was optimized using the electrostatic repulsion algorithm, combined with optimal ordering. The optimal protocol, using as few measurements as possible, was determined through leave‐n‐out analyses. Parsimonious model selection criteria were used to select between nested models, comprising up to three restricted compartments. The schemes were evaluated using both through Monte‐Carlo simulations and in vivo data.ResultsThe optimization/model selection procedure resulted in increased accuracy and precision on the estimated parameters, allowing for a reduction in acquisition time and marked improvements in data quality. The final protocol provided whole brain coverage data in only 12 min.ConclusionThrough careful optimization of the acquisition and analysis pipeline for the composite hindered and restricted model of diffusion, it is possible to reduce acquisition time for whole brain datasets to a time that is clinically applicable. Magn Reson Med 71:661–671, 2014. © 2013 Wiley Periodicals, Inc.
Detecting neuronal currents with MRI: A human study
Authors: Huang Jie 
Published: March 2013

PurposeRecently developed neuronal current magnetic resonance imaging aims to directly detect neuronal currents associated with brain activity, but controversial results have been reported in different studies on human subjects. Although there is no dispute that local neuronal currents produce weak transient magnetic fields that would attenuate local MR signal intensity, there is not yet consensus as to whether this attenuation is detectable with present magnetic resonance imaging techniques. This study investigates the magnitude of neuronal current‐induced signal attenuation in human visual cortex.TheoryA temporally well‐controlled visual stimulation paradigm with a known neuronal firing pattern in monkey visual cortex provides a means of detecting and testing the magnitude of the neuronal current‐induced attenuation in neuronal current magnetic resonance imaging.MethodsPlacing a series of acquisition windows to fully cover the entire response duration enables a thorough detection of any detectable MR signal attenuation induced by the stimulus‐evoked neuronal currents.ResultsNo significant neuronal current‐induced MR signal attenuation was observed in the putative V1 in any participated subjects.ConclusionThe present magnetic resonance imaging technique is not sensitive enough to detect neuronal current‐induced MR signal attenuation, and the upper limit of this attenuation was found to be less than 0.07% under the study condition. Magn Reson Med 71:756–762, 2014. © 2013 Wiley Periodicals, Inc.
Extension of GKB‐FP algorithm to large‐scale general‐form Tikhonov regularization
Authors: Viloche Bazán Fermín S. , Cunha Maria C.C. , Borges Leonardo S. 
Published: March 2013

SUMMARYIn a recent paper an algorithm for large‐scale Tikhonov regularization in standard form called GKB‐FP was proposed and numerically illustrated. In this paper, further insight into the convergence properties of this method is provided, and extensions to general‐form Tikhonov regularization are introduced. In addition, as alternative to Tikhonov regularization, a preconditioned LSQR method coupled with an automatic stopping rule is proposed. Preconditioning seeks to incorporate smoothing properties of the regularization matrix into the computed solution. Numerical results are reported to illustrate the methods on large‐scale problems. Copyright © 2013 John Wiley & Sons, Ltd.
The Z‐eigenvalues of a symmetric tensor and its application to spectral hypergraph theory
Authors: Li Guoyin , Qi Liqun , Yu Gaohang 
Published: March 2013

SUMMARYIn this paper, using variational analysis and optimization techniques, we examine some fundamental analytic properties of Z‐eigenvalues of a real symmetric tensor with even order. We first establish that the maximum Z‐eigenvalue function is a continuous and convex function on the symmetric tensor space and so provide formulas of the convex conjugate function and ε‐subdifferential of the maximum Z‐eigenvalue function. Consequently, for an mth‐order N‐dimensional tensor , we show that the normalized eigenspace associated with maximum Z‐eigenvalue function is ρth‐order Hölder stable at with . As a by‐product, we also establish that the maximum Z‐eigenvalue function is always at least ρth‐order semismooth at . As an application, we introduce the characteristic tensor of a hypergraph and show that the maximum Z‐eigenvalue function of the associated characteristic tensor provides a natural link for the combinatorial structure and the analytic structure of the underlying hypergraph. Finally, we establish a variational formula for the second largest Z‐eigenvalue for the characteristic tensor of a hypergraph and use it to provide lower bounds for the bipartition width of a hypergraph. Some numerical examples are also provided to show how one can compute the largest/second‐largest Z‐eigenvalue of a medium size tensor, using polynomial optimization techniques and our variational formula. Copyright © 2013 John Wiley & Sons, Ltd.
Mechanical characterization in laminated composite for cryogenic application
Authors: Oh Bong Taek , Lagoudas Dimitris C. , Moon SungCheal 
Published: March 2013

AbstractDamage in cryogenic composite fuel tanks induced during manufacturing and advanced by thermomechanical cycling can accelerate leakage of the propellant. Whether the leakage exceeds tolerable levels depends on many factors, including pressure gradients, microcrack density, other damage such as delamination, connectivity of the cracks, residual stresses from manufacture, service‐induced stresses from thermal and mechanical loads, and composite lay‐up. This article is concerned with the creation and the detection of damage in cryogenic composites due to thermomechanical loading. The first part deals with cryocycling (cycling between two temperatures) test procedures, that were developed to understand the damage produced in cryogenic composite laminates under thermomechanical loading. An apparatus was developed to thermomechanically cycle coupon test specimens under different thermomechanical loadings. IM7/977‐2 and IM7/5250‐4 graphite/epoxy cross‐ply [902/02]S and angle‐ply [0/‐45/90/45/0/45090/‐45/0]S laminates were tested using these systems. Ply‐by‐ply microcrack density was measured as a function of thermomechanical cycles. The second part of this article deals with effect of thermal gradients due to sudden exposure to a cryogenic temperature. The sudden exposure to cryogenic temperatures may have caused the microcracks, due to large temperature variations through the thickness and the resulting thermal stresses. In this work, an investigation of the sudden exposure to cryogenic temperatures is conducted experimentally with and without an insulating layer. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
Dependence of electrical properties of polyethylene nanocomposites on aspect ratio of carbon nanotubes
Authors: Rahaman Mostafizur , Thomas Selvin P. , Hussein Ibnelwaleed A. , De S.K. 
Published: March 2013

AbstractLow density polyethylene nanocomposites filled with carbon nanotubes (CNT) having three different aspect ratios have been prepared by melt mixing technique. The effects of CNT loading, its aspect ratio, and frequency of electric field on electrical and dielectric properties of the nanocomposites have been investigated. DC and AC electrical resistivity are found to decrease with the increase in CNT loading in the composites, while the dielectric constant and loss increase with the increase in CNT loading in the composites. AC electrical resistivity, dielectric constant, and dielectric loss decrease with the increase in frequency. Furthermore, the electrical resistivity decreases with the increase in aspect ratio of CNT, whereas the dielectric constant and loss increase with the increase in aspect ratio of CNT. While probable mechanisms for electrical conduction have been proposed, dielectric results have been explained by considering CNT as nanocapacitors. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
Crystal structure of the dimer of two essential Salmonella typhimurium proteins, YgjD & YeaZ and calorimetric evidence for the formation of a ternary YgjD–YeaZ–YjeE complex
Authors: Nichols C. E. , Lamb H.K. , Thompson P. , Omari K. El , Lockyer M. , Charles I. , Hawkins A. R. , Stammers D. K. 
Published: March 2013

AbstractYgjD from COG0533 is amongst a small group of highly conserved proteins present in all three domains of life. Various roles and biochemical functions (including sialoprotease and endonuclease activities) have been ascribed to YgjD and orthologs, the most recent, however, is involvement in the post transcriptional modification of certain tRNAs by formation of N6‐threonyl‐adenosine (t6A) at position 37. In bacteria, YgjD is essential and along with YeaZ, YjeE, and YrdC has been shown to be ‘necessary and sufficient’ for the tRNA modification. To further define interactions and possible roles for some of this set of proteins we have undertaken structural and biochemical studies. We show that formation of the previously reported heterodimer of YgjD–YeaZ involves ordering of the C‐terminal region of YeaZ which extends along the surface of YgjD in the crystal structure. ATPγS or AMP is observed in YgjD while no nucleotide is bound on YeaZ. ITC experiments reveal previously unreported binary and ternary complexes which can be nucleotide dependent. The stoichiometry of the YeaZ–YgjD complex is 1:1 with a KD of 0.3 µM. YgjD and YjeE interact only in the presence of ATP, while YjeE binds to YgjD‐YeaZ in the presence of ATP or ADP with a KD of 6 µM. YgjD doesn't bind the precursors of t6A, threonine, and bicarbonate. These results show a more complex set of interactions than previously thought, which may have a regulatory role. The understanding gained should help in deriving inhibitors of these essential proteins that might have potential as antibacterial drugs.