bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modern adjuncts and technologies in microsurgery: An historical and evidence‐based review
Authors: Pratt George F. , Rozen Warren M. , Chubb Daniel , Whitaker Iain S. , Grinsell Damien , Ashton Mark W. , Acosta Rafael 
Published: August 2010

AbstractBackground:While modern reconstructive surgery was revolutionized with the introduction of microsurgical techniques, microsurgery itself has seen the introduction of a range of technological aids and modern techniques aiming to improve dissection times, anastomotic times, and overall outcomes. These include improved preoperative planning, anastomotic aides, and earlier detection of complications with higher salvage rates. Despite the potential for substantial impact, many of these techniques have been evaluated in a limited fashion, and the evidence for each has not been universally explored. The purpose of this review was to establish and quantify the evidence for each technique.Methods:A search of relevant medical databases was performed to identify literature providing evidence for each technology. Levels of evidence were thus accumulated and applied to each technique.Results:There is a relative paucity of evidence for many of the more recent technologies described in the field of microsurgery, with no randomized controlled trials, and most studies in the field comprising case series only. Current evidence‐based suggestions include the use of computed tomographic angiography (CTA) for the preoperative planning of perforator flaps, the intraoperative use of a mechanical anastomotic coupling aide (particularly the Unilink® coupler), and postoperative flap monitoring with strict protocols using clinical bedside monitoring and/or the implantable Doppler probe.Conclusion:Despite the breadth of technologies introduced into the field of microsurgery, there is substantial variation in the degree of evidence presented for each, suggesting the role for much future research, particularly from emerging technologies such as robotics and modern simulators. © 2010 Wiley‐Liss, Inc. Microsurgery, 2010.
NMR quantification using an artificial signal
Authors: Farrant Roger D. , Hollerton John C. , Lynn Sean M. , Provera Stefano , Sidebottom Philip J. , Upton Richard J. 
Published: August 2010

AbstractWe have developed QUANTAS (QUANTification by Artificial Signal), which is a software‐based protocol for concentration measurement by NMR. QUANTAS is an absolute intensity external standard method for quantification by NMR that compensates for various experimental parameters. It is applicable to all nuclei and modern spectrometers. QUANTAS is demonstrated here for 1H and 19F NMR, enabling heteronuclear integrals to be compared. It can be applied using fixed probe tuning, matching and pulse length, for samples with the same effective loading on the probe coil as the appropriate reference spectrum. Otherwise, an optimised tuning and matching approach is adopted for every sample together with explicit PULCON (PUlse Length‐based CONcentration measurements) absolute intensity corrections. Copyright © 2010 John Wiley & Sons, Ltd.
Enhanced chromatographic NMR with polyethyleneglycol. A novel resolving agent for diffusion ordered spectroscopy
Authors: Kavakka Jari S. , Parviainen Viktor , Wähälä Kristiina , Kilpeläinen Ilkka , Heikkinen Sami 
Published: August 2010

AbstractNMR analysis of complex mixtures can be significantly simplified using polyethyleneglycol (PEG) as resolving additive in DOSY NMR technique, which allows the extraction of individual spectra of mixture components with differing polarity. Resolving power of PEG‐assisted DOSY was demonstrated with natural product mixtures. Copyright © 2010 John Wiley & Sons, Ltd.
Sperm status and DNA dose play key roles in sperm/ICSI‐mediated gene transfer in caprine
Authors: Shadanloo Farshad , Najafi Mohammad Hasan , Hosseini Sayed Morteza , Hajian Mehdi , Forouzanfar Mohsen , Ghaedi Kamran , Abedi Parvaneh , Ostadhosseini Somaye , Hosseini Laleh , Eskandari‐Nasab Morad‐Pasha , Esfahani Mohammad Hossein Nasr 
Published: August 2010

AbstractIn relation to the growing recent interest in the establishment of sperm‐mediated gene transfer (SMGT) technology as a convenient and effective method for the simple production of transgenic animals, in this study the possibility of using SMGT to produce transgenic caprine embryos was investigated for the first time. Buck sperm were directly incubated with different concentrations (0–500 ng) of pcDNA/his/Lac‐Z plasmid and used for IVF or ICSI. Sperm used for ICSI were categorized into motile or live‐immotile group before being injected into oocytes. In a separate experiment, dead sperm prepared by repeated freezing/thawing were used for DNA‐incubation before ICSI. Sham injection was carried out by intracytoplasmic injection of approximately the same volume of media containing different doses of DNA using an ICSI needle. Transgene expression and transmission were detected by X‐Gal staining and PCR analysis of developed embryos, respectively. A reasonable blastocyst rate was observed in all the groups. Only embryos in the sham group were negative for transgene transmission. Transgene expression was completely dependent on the delivery technique and status of sperm, and was only observed in the live‐immotile and dead ICSI groups. The results of this study showed that the technique (IVF vs. ICSI vs. sham injection), sperm status (motile vs. live‐immotile vs. dead) and to some extent DNA concentration affect embryo development, transgene transmission and expression. Mol. Reprod. Dev. 77:868–875, 2010. © 2010 Wiley‐Liss, Inc.
Caffeine treatment of ovine cytoplasts regulates gene expression and foetal development of embryos produced by somatic cell nuclear transfer
Authors: Choi Inchul , Lee Joon‐Hee , Fisher Pat , Campbell Keith H.S. 
Published: August 2010

AbstractTreatment of ovine oocytes during the latter stages of maturation in vitro with caffeine, a phosphodiesterase inhibitor, can increase the activities of maturation promoting factor and mitogen‐activated protein kinases at metaphase II. When used as cytoplast recipients for somatic cell nuclear transfer (NT), caffeine‐treated oocytes produced blastocysts with increased cell numbers. The objectives of these studies were to determine the effects of caffeine treatment on the expression profile of genes involved in early embryonic development and whether induction or maintenance of pregnancy was subsequently altered. No differences in overall expression patterns were observed between fertilised, caffeine‐treated fertilised and parthenogenetic embryos. In control NT embryos, altered levels of gene expression were found for OCT4, five genes regulated by OCT4 (H2AF.Z, NANOG, SOX2, FGF4 and INFT) and the heat‐shock response genes (HSP27 and HSP70.1). Levels of OCT4, H2AF.Z, NANOG, HSP 27 and FGF4 decreased, while those of INFT, HSP70.1 and SOX2 increased. In contrast, expression levels of these genes in caffeine‐treated NT embryos were similar to those in fertilised controls. Following transfer to surrogate recipients no differences were observed in the frequency of pregnancy; however, ewes receiving caffeine‐treated embryos maintained pregnancies for longer periods and delivered a live lamb. Taken together, these results suggest that treatment of ovine oocytes with caffeine can affect gene expression and improve developmental competence. Further studies on the mechanisms behind this alteration of gene expression are required and will aid in understanding the molecular mechanisms involved in nuclear reprogramming. Mol. Reprod. Dev. 77:876–887, 2010. © 2010 Wiley‐Liss, Inc.
MRI contrast from relaxation along a fictitious field (RAFF)
Authors: Liimatainen Timo , Sorce Dennis J. , O'Connell Robert , Garwood Michael , Michaeli Shalom 
Published: August 2010

AbstractA new method to measure rotating frame relaxation and to create contrast for MRI is introduced. The technique exploits relaxation along a fictitious field (RAFF) generated by amplitude‐ and frequency‐modulated irradiation in a subadiabatic condition. Here, RAFF is demonstrated using a radiofrequency pulse based on sine and cosine amplitude and frequency modulations of equal amplitudes, which gives rise to a stationary fictitious magnetic field in a doubly rotating frame. According to dipolar relaxation theory, the RAFF relaxation time constant (TRAFF) was found to differ from laboratory frame relaxation times (T1 and T2) and rotating frame relaxation times (T1ρ and T2ρ). This prediction was supported by experimental results obtained from human brain in vivo and three different solutions. Results from relaxation mapping in human brain demonstrated the ability to create MRI contrast based on RAFF. The value of TRAFF was found to be insensitive to the initial orientation of the magnetization vector. In the RAFF method, the useful bandwidth did not decrease as the train length increased. Finally, as compared with an adiabatic pulse train of equal duration, RAFF required less radiofrequency power and therefore can be more readily used for rotating frame relaxation studies in humans. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Contrast‐enhanced in vivo magnetic resonance microscopy of the mouse brain enabled by noninvasive opening of the blood‐brain barrier with ultrasound
Authors: Howles Gabriel P. , Bing Kristin F. , Qi Yi , Rosenzweig Stephen J. , Nightingale Kathryn R. , Johnson G. Allan 
Published: August 2010

AbstractThe use of contrast agents for neuroimaging is limited by the blood‐brain barrier (BBB), which restricts entry into the brain. To administer imaging agents to the brain of rats, intracarotid infusions of hypertonic mannitol have been used to open the BBB. However, this technically challenging approach is invasive, opens only a limited region of the BBB, and is difficult to extend to mice. In this work, the BBB was opened in mice, using unfocused ultrasound combined with an injection of microbubbles. This technique has several notable features: it (a) can be performed transcranially in mice; (b) takes only 3 min and uses only commercially available components; (c) opens the BBB throughout the brain; (d) causes no observed histologic damage or changes in behavior (with peak‐negative acoustic pressures of 0.36 MPa); and (e) allows recovery of the BBB within 4 h. Using this technique, Gadopentetate Dimeglumine (Gd‐DTPA) was administered to the mouse brain parenchyma, thereby shortening T1 and enabling the acquisition of high‐resolution (52 × 52 × 100 micrometers3) images in 51 min in vivo. By enabling the administration of both existing anatomic contrast agents and the newer molecular/sensing contrast agents, this technique may be useful for the study of mouse models of neurologic function and pathology with MRI. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Noninvasive detection of pulmonary tissue destruction in a mouse model of emphysema using hyperpolarized 129Xe MRS under spontaneous respiration
Authors: Imai Hirohiko , Kimura Atsuomi , Iguchi Satoshi , Hori Yuki , Masuda Shoko , Fujiwara Hideaki 
Published: August 2010

AbstractIn the present study, a chemical shift saturation recovery method in hyperpolarized 129Xe MR spectroscopy measurements was applied to two groups of spontaneously breathing mice, an elastase‐induced emphysema model and a control group. Parameters detected were those related to lung structures and functions, such as alveolar septal thickness, h, the ratio of the alveolar septal volume relative to gas space volume, Vs/Va, and the transit time of blood through the gas exchange region, τ. To investigate the potential of these parameters as biomarkers, an attempt was made to detect physiologic changes in the lungs of elastase‐treated mice. Our results showed that Vs/Va was significantly reduced in elastase‐treated mice, reflecting emphysema‐like destruction of the alveolar wall. Compared with histologic results, this degree of reduction was shown to reflect the severity of wall destruction. On the other hand, significant changes in other parameters, h and τ, were not shown. This study is the first application of hyperpolarized 129Xe MR spectroscopy to a mouse model of emphysema and shows that the Vs/Va volume ratio is an effective biomarker for emphysema that could become useful in drug research and development through noninvasive detection of pathologic changes in small rodents. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Ongoing dual‐angle measurements for the correction of partial saturation in 31P MR spectroscopy
Authors: Tyler Damian J. , Lopez Orlando , Cole Mark A. , Carr Carolyn A. , Stuckey Daniel J. , Lakatta Edward , Clarke Kieran , Spencer Richard G. 
Published: August 2010

AbstractUse of a repetition time similar to, or shorter than, metabolite T1s is common in NMR spectroscopy of biological samples to improve the signal‐to‐noise ratio. Conventionally, the partial saturation that results from this is corrected using saturation factors. However, this can lead to erroneous results in the presence of chemical exchange or nonconstant T1s. We describe an alternative approach to correction for saturation, based on ongoing dual‐angle T1 measurement. Using 31P magnetic resonance spectroscopy of the perfused rat heart undergoing ischemia‐reperfusion, we demonstrate that signal alternations in the data acquired by the dual‐angle approach are eliminated by the ongoing dual‐angle T1 measurement correction scheme, meaning that metabolite concentration and T1 measurement can be made throughout the course of the ischemia‐reperfusion protocol. Simulations, based on parameters pertinent to the perfused rat heart, demonstrate that accurate saturation correction is possible with this method except at times of rapid concentration change. Additionally, compared to the conventional saturation factor correction method, the ongoing dual‐angle T1 measurement correction scheme results in improved accuracy in determining the [phosphocreatine] recovery time constant. Thus, the ongoing dual‐angle T1 measurements procedure permits accurate monitoring of metabolite concentrations even in the setting of chemical exchange and T1 changes and allows more accurate analysis of bioenergetic status. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Human brain atlas‐based volumetry and relaxometry: Application to healthy development and natural aging
Authors: Hasan Khader M. , Walimuni Indika S. , Kramer Larry A. , Frye Richard E. 
Published: August 2010

AbstractThis work investigated the feasibility and utility of using T2‐weighted or dual spin‐echo data to provide volume and T2 relaxation time for regional and global gray and white matter using standardized brain templates and anatomically labeled atlases. A total of 130 healthy males and females (age range 15–59 years) were included. Dual echo magnetic resonance imaging data were acquired and analyzed using standardized International Consortium for Human Brain Mapping atlas‐based tissue segmentation procedures implemented in the statistical parametric mapping toolbox to obtain the age trajectories of volume and corresponding T2 relaxation time in whole brain white and gray matter, in the caudate nucleus and in the anterior limb of internal capsule. Whole brain gray matter and caudate nucleus volumes linearly decreased with age while whole brain white matter and anterior limb internal capsule volume increased slowly with age bilaterally in males and females. The relation between T2 relaxation time and age of whole brain gray and white matter, and caudate nucleus and anterior limb internal capsule followed a quadratic U‐curve. The T2 relaxation times of the human brain followed a U curve both globally and regionally in both white and gray matter. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Strain and torsion quantification in mouse hearts under dobutamine stimulation using 2D multiphase MR DENSE
Authors: Zhong Jia , Yu Xin 
Published: August 2010

AbstractIn this study, a 2D multiphase magnetic resonance displacement encoding with stimulated echoes (DENSE) imaging and analysis method was developed for direct quantification of Lagrangian strain in the mouse heart. Using the proposed method, <10 ms temporal resolution and 0.56 mm in‐plane resolution were achieved. A validation study that compared strain calculation by displacement encoding with stimulated echoes and by magnetic resonance tagging showed high correlation between the two methods (R2 > 0.80). Regional ventricular wall strain and twist were characterized in mouse hearts at baseline and under dobutamine stimulation. Dobutamine stimulation induced significant increase in radial and circumferential strains and torsion at peak systole. A rapid untwisting was also observed during early diastole. This work demonstrates the capability of characterizing cardiac functional response to dobutamine stimulation in the mouse heart using 2D multiphase magnetic resonance displacement encoding with stimulated echoes. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Performance of external and internal coil configurations for prostate investigations at 7 T
Authors: Metzger Gregory J. , van de Moortele Pierre‐Francois , Akgun Can , Snyder Carl J. , Moeller Steen , Strupp John , Andersen Peter , Shrivastava Devashish , Vaughan Tommy , Ugurbil Kamil , Adriany Gregor 
Published: August 2010

AbstractThree different coil configurations were evaluated through simulation and experimentally to determine safe operating limits and evaluate subject size‐dependent performance for prostate imaging at 7 T. The coils included a transceiver endorectal coil (trERC), a 16‐channel transceiver external surface array (trESA) and a trESA combined with a receive‐only ERC (trESA+roERC). Although the transmit B1 (B) homogeneity was far superior for the trESA, the maximum achievable B is subject size dependent and limited by transmit chain losses and amplifier performance. For the trERC, limitations in transmit homogeneity greatly compromised image quality and limited coverage of the prostate. Despite these challenges, the high peak B close to the trERC and subject size‐independent performance provides potential advantages especially for spectroscopic localization where high‐bandwidth radiofrequency pulses are required. On the receive side, the combined trESA+roERC provided the highest signal‐to‐noise ratio and improved homogeneity over the trERC resulting in better visualization of the prostate and surrounding anatomy. In addition, the parallel imaging performance of the trESA+roERC holds strong promise for diffusion‐weighted imaging and dynamic contrast‐enhanced MRI. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Reference‐based linear curve fitting for bolus arrival time estimation in 4D MRA and MR perfusion‐weighted image sequences
Authors: Forkert Nils Daniel , Fiehler Jens , Ries Thorsten , Illies Till , Möller Dietmar , Handels Heinz , Säring Dennis 
Published: August 2010

AbstractThe bolus arrival time (BAT) based on an indicator dilution curve is an important hemodynamic parameter. As the direct estimation of this parameter is generally problematic, various parametric models have been proposed that describe typical physiological shapes of indicator dilution curves, but it remains unclear which model describes the real physiological background. This article presents a method that indirectly incorporates physiological information derived from the data available. For this, a patient‐specific hemodynamic reference curve is extracted, and the corresponding reference BAT is determined. To estimate a BAT for a given signal curve, the reference curve is fitted linearly to the signal curve. The parameters of the fitting process are then used to transfer the reference BAT to the signal curve. The validation of the method proposed based on Monte Carlo simulations showed that the approach presented is capable of improving the BAT estimation precision compared with standard BAT estimation methods by up to 59% while at the same time reduces the computation time. A major benefit of the method proposed is that no assumption about the underlying distribution of indicator dilution has to be made, as it is implicitly modeled in the reference curve. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Protein polymer MRI contrast agents: Longitudinal analysis of biomaterials in vivo
Authors: Karfeld‐Sulzer Lindsay S. , Waters Emily A. , Kohlmeir Ellen K. , Kissler Hermann , Zhang Xiaomin , Kaufman Dixon B. , Barron Annelise E. , Meade Thomas J. 
Published: August 2010

AbstractDespite recent advances in tissue engineering to regenerate biological function by combining cells with material supports, development is hindered by inadequate techniques for characterizing biomaterials in vivo. Magnetic resonance imaging is a tomographic technique with high temporal and spatial resolution and represents an excellent imaging modality for longitudinal noninvasive assessment of biomaterials in vivo. To distinguish biomaterials from surrounding tissues for magnetic resonance imaging, protein polymer contrast agents were developed and incorporated into hydrogels. In vitro and in vivo images of protein polymer hydrogels, with and without covalently incorporated protein polymer contrast agents, were acquired by magnetic resonance imaging. T1 values of the labeled gels were consistently lower when protein polymer contrast agents were included. As a result, the protein polymer contrast agent hydrogels facilitated fate tracking, quantification of degradation, and detection of immune response in vivo. For the duration of the in vivo study, the protein polymer contrast agent‐containing hydrogels could be distinguished from adjacent tissues and from the foreign body response surrounding the gels. The hydrogels containing protein polymer contrast agent have a contrast‐to‐noise ratio 2‐fold greater than hydrogels without protein polymer contrast agent. In the absence of the protein polymer contrast agent, hydrogels cannot be distinguished by the end of the gel lifetime. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Highly localized positive contrast of small paramagnetic objects using 3D center‐out radial sampling with off‐resonance reception
Authors: Seevinck Peter R. , de Leeuw Hendrik , Bos Clemens , Bakker Chris J. G. 
Published: August 2010

AbstractIn this article, we present a 3D imaging technique, applying center‐out RAdial Sampling with Off‐Resonance reception, to accurately depict and localize small paramagnetic objects with high positive contrast while suppressing long T2* components. The center‐out RAdial Sampling with Off‐Resonance reception imaging technique is a fully frequency‐encoded 3D ultrashort echo time acquisition method, which uses a large excitation bandwidth and off‐resonance reception. By manually introducing an offset, Δf0, to the central reception frequency (f0), the typical radial signal pileup observed in 3D center‐out sampling caused by a dipolar magnetic field disturbance can be shifted toward the source of the field disturbance, resulting in a hyperintense signal at the magnetic center of the small paramagnetic object. This was demonstrated both theoretically and using 1D time domain simulations. Experimental verification was done in a gel phantom and in inhomogeneous porcine tissue containing various objects with very different geometry and susceptibility, namely, subvoxel stainless steel spheres, a puncture needle, and paramagnetic brachytherapy seeds. In all cases, center‐out RAdial Sampling with Off‐Resonance reception was shown to generate high positive contrast exactly at the location of the paramagnetic object, as was confirmed by X‐ray computed tomography. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.