bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevalence of antiphospholipid antibodies in Chilean patients with rheumatoid arthritis
Authors: Palomo Iván , Pinochet Carmen , Alarcón Marcelo , Sandoval Rodrigo , Gonzalez Jaime , Monsalves Francisco , Forastiero Ricardo 
Published: September 2006

AbstractAntiphospholipid (aPL) antibodies found in patients with autoimmune diseases are also detected in those with inflammatory diseases. The purpose of this study was to examine the prevalence of these antibodies in patients with rheumatoid arthritis (RA), and to evaluate the association of these antibodies with thrombosis and/or other clinical characteristics of this inflammatory disorder. Eighty‐four patients with RA and 82 normal controls were studied. Anticardiolipin (aCL), anti‐β2 glycoprotein I (anti‐β2GPI), and antiprothrombin (aPT) antibodies and the lupus anticoagulant (LA) activity were determined. Seven out of 84 (8.3%) patients were positive for aCL, six out of 84 (7.2%) for anti‐β2GPI, and six out of 84 (7.2%) for aPT, while in controls the overall prevalence of aPL antibodies was 3.6% (3 out of 82). All patients and controls were LA negative. There was no correlation between the presence of aPL with thrombosis and/or other clinical features of the antiphospholipid syndrome. We found aPL antibodies in 19.1% (16 out of 84) of the patients with rheumatoid arthritis and this prevalence was statistically higher than in normal controls (P<0.003). In this study, the presence of aPL antibodies was not associated with the development of thrombosis and/or thrombocytopenia. Whether the presence of aPL antibodies implies an increased risk for thrombosis and atherosclerosis in these patients should be studied further. J. Clin. Lab. Anal. 20:190–194, 2006. © 2006 Wiley‐Liss, Inc.
Adenoviral vector platform for transduction of constitutive and regulated tricistronic or triple‐transcript transgene expression in mammalian cells and microtissues
Authors: Gonzalez‐Nicolini Valeria , Sanchez‐Bustamante Carlota Diaz , Hartenbach Shizuka , Fussenegger Martin 
Published: September 2006

AbstractBackgroundAdenoviral particles can efficiently transduce a broad spectrum of cell types, so they are widely used in basic research and clinical trials.MethodsWe have developed a novel adenoviral vector platform for delivery of constitutive or streptogramin‐inducible expression of up to three therapeutic transgenes into a variety of murine and human cell lines, primary cells and microtissues.ResultsCoordinated expression of three independent transgenes in a compact genetic format was achieved by two different expression configurations: (i) The multicistronic expression format consisting of a single constitutive (simian virus 40 promoter, PSV40; murine or human cytomegalovirus immediate‐early promoter, PmCMV, PhCMV) or regulated (streptogramin‐inducible) promoters (PPIRON2) driving the expression of a single multicistronic transcript of which the first cistron is translated in a cap‐dependent manner and the two subsequent ones by internal ribosome entry site (IRES)‐mediated translation initiation. (ii) The triple‐transcript expression configuration, in which a combination of well‐established (PSV40, PhCMV, PmCMV) and novel synthetic constitutive promoters (PGTX) control transcription of three expression units. The constitutive multigene expression design enabled coordinated high‐level expression of the Bacillus stearothermophilus‐derived secreted α‐amylase (SAMY), the human vascular endothelial growth factor 121 (VEGF121) and the human placental secreted alkaline phosphatase (SEAP) in monolayer populations and microtissues of Chinese hamster ovary cells (CHO‐K1), human fibrosarcoma cells (HT‐1080), primary neonatal rat cardiomyocytes (NRCs) and primary human aortic fibroblasts (HAFs). Streptogramin‐inducible tricistronic SAMY‐VEGF121‐SEAP expression provided excellent regulation performance—high‐level induction in the presence of the streptogramin antibiotic pristinamycin I (PI), near‐undetectable basal expression in the absence of PI, optimal adjustability and perfect reversibility—in all cell types, in particular in NRCs and NRC‐derived myocardial microtissues.ConclusionsTriple‐transcript and tricistronic expression configurations conserve the DNA packaging capacity of the size‐constrained viral transduction systems and enable coordinated and regulated expression of up to three therapeutic transgenes for concerted clinical interventions in future gene therapy scenarios. Copyright © 2006 John Wiley & Sons, Ltd.
The Raman noncoincidence effect of the ν(CO) band of ME6N liquid crystal across the nematic–isotropic phase transition studied by a micro‐spectroscopy experiment
Authors: Giorgini M. G. , Arcioni A. , Venditti G. , Musso M. 
Published: September 2006

AbstractThe Raman spectroscopic noncoincidence effect (NCE) of the ν(CO) band of the liquid crystal ME6N (4‐cyanophenyl‐4′‐hexylbenzoate) has been measured at different temperatures (47–52 °C) around the nematic‐isotropic phase transition (47.8 °C) employing a micro‐Raman experiment under confocal conditions and performed on a homogeneously aligned thin sample. The low value of NCE (0.9 cm−1) obtained over the whole temperature range suggests that the orientational structure of the liquid crystal in both phases is governed by the steric hindrances in the proximity of the carbonyl group, rather than by dipolar interactions. This hypothesis is supported by the results of a supplementary investigation of the NCE of the ν(CO) Raman band in liquid ketones and esters, made progressively more hampered by the insertion of bulky (phenyl) groups in proximity of the carbonyl group. The NCE of the ν(CO) band, in fact, decreases from 5.5 cm−1 in acetone (the less hampered) to 0.7 cm−1 in benzophenone (the most hampered among the studied ketones), and from 6.2 cm−1 in methyl acetate (the less hampered) to 2.2 cm−1 in phenyl benzoate (the most hampered among the studied esters). To our best knowledge, this represents the first attempt to analyze the NCE in terms of steric hindrance of the substituents around the target oscillator. A parallel analysis of the difference between the anisotropic and the isotropic bandwidths of the ν(CO) Raman band in these molecular liquids indicates that reorientational dynamics plays only a marginal role, if any. Copyright © 2006 John Wiley & Sons, Ltd.
Dynamic magnetic resonance inverse imaging of human brain function
Authors: Lin Fa‐Hsuan , Wald Lawrence L. , Ahlfors Seppo P. , Hämäläinen Matti S. , Kwong Kenneth K. , Belliveau John W. 
Published: September 2006

AbstractMRI is widely used for noninvasive hemodynamic‐based functional brain imaging. In traditional spatial encoding, however, gradient switching limits the temporal resolution, which makes it difficult to unambiguously identify possible fast nonhemodynamic changes. In this paper we propose a novel reconstruction approach, called dynamic inverse imaging (InI), that is capable of providing millisecond temporal resolution when highly parallel detection is used. To achieve an order‐of‐magnitude speedup in generating time‐resolved contrast estimates and dynamic statistical parametric maps (dSPMs), the spatial information is derived from an array of detectors rather than by time‐consuming gradient‐encoding methods. The InI approach was inspired by electroencephalography (EEG) and magnetoencephalography (MEG) source localization techniques. Dynamic MR InI was evaluated by means of numerical simulations. InI was also applied to measure BOLD hemodynamic time curves at 20‐ms temporal resolution in a visual stimulation experiment using a 90‐channel head array. InI is expected to improve the time resolution of MRI and provide increased flexibility in the trade‐off between spatial and temporal resolution for studies of dynamic activation patterns in the human brain. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
On restoring motion‐induced signal loss in single‐voxel magnetic resonance spectra
Authors: Gabr Refaat E. , Sathyanarayana Shashank , Schär Michael , Weiss Robert G. , Bottomley Paul A. 
Published: September 2006

AbstractDestructive interference from phase fluctuations caused by motion during 1H magnetic resonance spectroscopy (MRS) stimulated‐echo acquisition mode (STEAM) and point‐resolved spectroscopy (PRESS) acquisitions can significantly diminish the traditional √N‐gain in signal‐to‐noise ratio (SNR) afforded by averaging N signals, especially in the torso. The SNR loss is highly variable among individuals, even when identical acquisition protocols are used. This paper presents a theory for the SNR loss, assuming that the phase fluctuates randomly. It is shown that SNR in conventional averaging is reduced by the factor sinc(σϕ√3/π), where σϕ is the standard deviation (SD) of the phase. “Constructive averaging,” whereby each individual acquisition is phase‐corrected using the phase of a high‐SNR peak before averaging, reverses the SNR loss from motion‐induced dephasing, resulting in a {1/sinc(σϕ√3/π)}‐fold SNR improvement. It is also shown that basing phase corrections on an average of √N adjacent points both improves correction accuracy and effectively eliminates false signal artifacts when corrections are based on low‐SNR peaks. The theory is validated over a sevenfold range of variation in signal loss due to motion observed in 1H STEAM and PRESS data acquired from 17 human subjects (heart: N = 16; leg: N = 1). Constructive averaging should be incorporated as a routine tool for in vivo 1H MRS. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Enhanced T2 contrast for MR histology of the mouse brain
Authors: Sharief Anjum Ali , Johnson G. Allan 
Published: September 2006

AbstractA 3D Carr‐Purcell‐Meiboom‐Gill (CPMG) sequence was implemented to obtain enhanced T2 contrast in actively stained (perfusion with fixative and contrast agent) mouse brains at 9.4 T. Short interecho spacing was used to minimize diffusion and susceptibility losses. The sequence produced 16 3D volumes with an interecho spacing of 7 ms for isotropic 43‐μ‐resolution images of the mouse brains in a scan time of 4 hr. To enhance the signal‐to‐noise ratio (SNR) and contrast, the multiecho frequency domain image contrast (MEFIC) method was applied, resulting in a composite image with T2‐weighted contrast. The high SNR and contrast thus achieved revealed aspects of mouse brain morphology, such as multiple cortical layers, groups of thalamic nuclei, layers of the inferior and superior colliculus, and molecular and granular layers of the cerebellum, with a high degree of definition and contrast that was not previously achieved in T2‐weighted acquisitions at high fields. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Age and gender dependence of human cardiac phosphorus metabolites determined by SLOOP 31P MR spectroscopy
Authors: Köstler Herbert , Landschütz Wilfried , Koeppe Sabrina , Seyfarth Tobias , Lipke Claudia , Sandstede Jörn , Spindler Matthias , von Kienlin Markus , Hahn Dietbert , Beer Meinrad 
Published: September 2006

AbstractThe aim of this study was to apply 31P magnetic resonance spectroscopy (MRS) using spatial localization with optimal point spread function (SLOOP) to investigate possible age and gender dependencies of the energy metabolite concentrations in the human heart. Thirty healthy volunteers (18 males and 12 females, 21–67 years old, mean = 40.7 years) were examined with the use of 31P‐MRS on a 1.5 T scanner. Intra‐ and interobserver variability measures (determined in eight of the volunteers) were both 3.8% for phosphocreatine (PCr), and 4.7% and 8.3%, respectively, for adenosine triphosphate (ATP). High‐energy phosphate (HEP) concentrations in mmol/kg wet weight were 9.7 ± 2.4 (age < 40 years, N = 16) and 7.7 ± 2.5 (age ≥ 40 years, N = 14) for PCr, and 5.1 ± 1.0 (age < 40 years) and 4.1 ± 0.8 (age ≥ 40 years) for ATP, respectively. Separated by gender, PCr concentrations of 9.2 ± 2.4 (men, N = 18) and 8.0 ± 2.8 (women, N = 12) and ATP concentrations of 4.9 ± 1.0 (men) and 4.2 ± 0.9 (women) were measured. A significant decrease of PCr and ATP was found for volunteers older than 40 years (P < 0.05), but the differences in metabolic concentrations between both sexes were not significant. In conclusion, age has a minor but still significant impact on cardiac energy metabolism, and no significant gender differences were detected. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Optimized detection of lactate at high fields using inner volume saturation
Authors: Edden Richard A.E. , Schär Michael , Hillis Argye E. , Barker Peter B. 
Published: September 2006

AbstractIn localized proton MR spectroscopy (1H‐MRS) in vivo, the detection of lactate (Lac) is affected by modulation of its resonances due to homonuclear scalar couplings (J). A simple and convenient way to distinguish Lac from lipids is to set the TE to 1/J so that the Lac signal is inverted while other resonances (such as lipid) remain in‐phase. However, at high field strengths, such as 3 Tesla or above, the modulation of the Lac signal is complicated by chemical shift effects that cause modulation patterns to vary within different subregions of the localized volume. Under some conditions the Lac signal may even disappear completely. In this note we introduce the concept of inner volume saturation (IVS), which makes use of high bandwidth spatial pulses to remove the signal corresponding to the regions of the localized volume that contribute unwanted modulation patterns. The method is described theoretically and demonstrated experimentally at 3 Tesla in a phantom and a patient with acute stroke. The phantom measurements indicate that virtually 100% of the Lac signal can be recovered using this method. The method should be feasible at magnetic fields above 3 Tesla, and may also be applied to other coupled spin systems in which modulation effects are important. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Pulsed magnetization transfer imaging with body coil transmission at 3 Tesla: Feasibility and application
Authors: Smith Seth A. , Farrell Jonathan A.D. , Jones Craig K. , Reich Daniel S. , Calabresi Peter A. , van Zijl Peter C.M. 
Published: September 2006

AbstractPulsed magnetization transfer (MT) imaging has been applied to quantitatively assess brain pathology in several diseases, especially multiple sclerosis (MS). To date, however, because of the high power deposition associated with the use of short, rapidly repeating MT prepulses, clinical application has been limited to lower field strengths. The contrast‐to‐noise ratio (CNR) of MT is limited, and this method would greatly benefit from the use of higher magnetic fields and phased‐array coil reception. However, power deposition is proportional to the square of the magnetic field and scales with coil size, and MT experiments are already close to the SAR limit at 1.5T even when smaller transmit coils are used instead of the body coil. Here we show that these seemingly great obstacles can be ameliorated by the increased T1 of tissue water at higher field, which allows for longer maintenance of sufficiently high saturation levels while using a reduced duty cycle. This enables a fast (5–6 min) high‐resolution (1.5 mm isotropic) whole‐brain MT acquisition with excellent anatomical visualization of gray matter (GM) and white matter (WM) structures, and even substructures. The method is demonstrated in nine normal volunteers and five patients with relapsing remitting MS (RRMS), and the results show a clear delineation of heterogeneous lesions. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
The role of altered acetyl‐CoA carboxylase in conferring resistance to fenoxaprop‐P‐ethyl in Chinese sprangletop (Leptochloa chinensis (L.) Nees)
Authors: Pornprom Tosapon , Mahatamnuchoke Parnuwat , Usui Kenji 
Published: September 2006

AbstractFrom paddy field observations in 2002 and 2004, fenoxaprop‐P‐ethyl resistance in Chinese sprangletop (Leptochloa chinensis (L.) Nees) has been studied using information collected from 11 sites in the Saphan‐Sung district of Bangkok, Thailand. The resistant Chinese sprangletop was found in nine rice fields, whereas the susceptible Chinese sprangletop was found in only two rice fields. In greenhouse experiments, both fenoxaprop‐P‐ethyl‐resistant and susceptible Chinese sprangletop from the same location were investigated for 50% growth reduction based on phytotoxicity, plant height and fresh and dry weight. The resistant Chinese sprangletop showed apparent resistance at 14–21 days after herbicide application at a rate of 21.1–337.6 g AI ha−1. The resistance index of resistant Chinese sprangletop was 10–25 times higher than that of the susceptible Chinese sprangletop. In addition, Chinese sprangletop did not exhibit multiple resistance to oxadiazon, propanil and quinclorac. According to acetyl‐CoA carboxylase (ACCase) assays, the level of ACCase specific activity in the resistant Chinese sprangletop was significantly higher than that in the susceptible Chinese sprangletop. Similarly, the ACCase activity of the resistant Chinese sprangletop was 10 times less sensitive to fenoxaprop‐P‐ethyl than that of the susceptible Chinese sprangletop, based on the I50 values. The present study of the mechanism responsible for resistance in the biotypes investigated indicated that there was a close association between the concentration–response at the whole‐plant level and ACCase sensitivity to fenoxaprop‐P‐ethyl, and resistance to fenoxaprop‐P‐ethyl was conferred by a modified ACCase at the target site, as suggested by higher specific activity and less sensitivity to the herbicide. Copyright © 2006 Society of Chemical Industry
The role of medical simulation: an overview
Authors: Kunkler Kevin 
Published: September 2006

AbstractRobotic surgery and medical simulation have much in common: both use a mechanized interface that provides visual “patient” reactions in response to the actions of the health care professional (although simulation also includes touch feedback); both use monitors to visualize the progression of the procedure; and both use computer software applications through which the health care professional interacts. Both technologies are experiencing rapid adoption and are viewed as modalities that allow physicians to perform increasingly complex minimally invasive procedures while enhancing patient safety. A review of the literature and industry developments concludes that medical simulators can be useful tools in determining a physician's understanding and use of best practices, management of patient complications, appropriate use of instruments and tools, and overall competence in performing procedures.Future use of these systems depends on their impact on patient safety, procedure completion time and cost efficiency. The sooner simulation training can be used to support developing technologies and procedures, the earlier, and typically the better, the results. Continued studies are needed to identify and ensure the ongoing applicability of these systems for both training and certification. Copyright © 2006 John Wiley & Sons, Ltd.
Long‐distance robotic telesurgery: a feasibility study for care in remote environments
Authors: Rayman R. , Croome K. , Galbraith N. , McClure R. , Morady R. , Peterson S. , Smith S. , Subotic V. , Van Wynsberghe A. , Primak S. 
Published: September 2006

AbstractBackgroundBasic telesurgical manoeuvres were conducted with signal delays.MethodsEight test subjects conducted four manoeuvres. Time delays of 0–1000 ms were investigated. Time to task completion and error rate were recorded in sequential delays of 0–600 ms. Additionally, blinded random delays of 0–1000 ms were studied.ResultsIn the sequential trials (0–600 ms), there were no significant differences in average task time compared to zero latency. The error rate remained low despite increasing time delay, and was significantly less at 500 ms (p< 0.05). In the random trials, task time was significantly greater at delays of 500, 600, 800 and 1000 ms (p< 0.05). There were no significant differences in error rates (p= 0.252).ConclusionsOperators are capable of performing surgical exercises at significant delays. Latent video feedback is difficult for telesurgery. Visual or virtual reality cues should be implemented to aid the operator in a high‐cadence telesurgery environment. Copyright © 2006 John Wiley & Sons, Ltd.
Analysing multicentre competing risks data with a mixed proportional hazards model for the subdistribution
Authors: Katsahian Sandrine , Resche‐Rigon Matthieu , Chevret Sylvie , Porcher Raphaël 
Published: September 2006

AbstractIn the competing‐risks setting, to test the effect of a covariate on the probability of one particular cause of failure, the Fine and Gray model for the subdistribution hazard can be used. However, sometimes, competing risks data cannot be considered as independent because of a clustered design, for instance in registry cohorts or multicentre clinical trials. Frailty models have been shown useful to analyse such clustered data in a classical survival setting, where only one risk acts on the population. Inclusion of random effects in the subdistribution hazard has not been assessed yet.In this work, we propose a frailty model for the subdistribution hazard. This allows first to assess the heterogeneity across clusters, then to incorporate such an effect when testing the effect of a covariate of interest. Based on simulation study, the effect of the presence of heterogeneity on testing for covariate effects was studied. Finally, the model was illustrated on a data set from a registry cohort of patients with acute myeloid leukaemia who underwent bone marrow transplantation. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of pinealectomy and melatonin replacement on morphological and biochemical recovery after traumatic brain injury
Authors: Ates Ozkan , Cayli Suleyman , Gurses Iclal , Yucel Neslihan , Iraz Mustafa , Altinoz Eyup , Kocak Ayhan , Yologlu Saim 
Published: September 2006

AbstractNumerous studies showed that melatonin, a free radical scavenger, is neuroprotective. In this study, we investigated the effect of pinealectomy and administration of exogenous melatonin on oxidative stress and morphological changes after experimental brain injury.The animals were divided into six groups, each having 12 rats. Group 1 underwent craniotomy alone. Group 2 underwent craniotomy followed by brain trauma and received no medication. Group 3 underwent craniotomy followed by brain trauma and received melatonin. Group 4 underwent pinealectomy and craniotomy alone. Group 5 underwent pinealectomy and craniotomy followed by brain injury and received no medication. Group 6 underwent pinealectomy and craniotomy followed by brain trauma and received melatonin. Melatonin (100 mg/kg) was given intraperitoneally immediately after trauma to the rats in Groups 3 and 6.Pinealectomy caused a significant increase in the malondialdehyde (MDA), nitric oxide (NO), glutathione (GSH), and xanthine oxidase (XO) levels, and a decrease in GSH levels as compared to the control group. Trauma to pinealectomized rats causes significantly higher oxidative stress. Exogeneous melatonin administration significantly reduced MDA, XO and NO levels, increased GSH levels, and attenuated tissue lesion area. These findings suggest that reduction in endogenous melatonin after pinealectomy makes the rats more vulnerable to trauma, and exogenous melatonin administration has an important neuroprotective effect.