bluuebunny/crossref_metadata_2025 huggingface dataset:
Time‐resolved MR angiography with limited projections
Authors: Huang Yuexi , Wright Graham A.
Published: July 2007

A method for reconstruction of time‐resolved MRI called highly‐constrained backprojection (HYPR) has been developed. To evaluate the HYPR reconstruction in relation to data sparsity and temporal dynamics, computer simulations were performed, investigating signal modulations under different situations that reflect dynamic contrast‐enhanced MR angiography (MRA). In vivo studies were also performed with gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) for abdominal MRA in a canine model to demonstrate the application of HYPR for three‐dimensional (3D) time‐resolved MRA. When contrast dynamics vary over space, large vessels (e.g., veins) tend to introduce signal interference to small vessels (e.g., arteries) in HYPR, particularly when the vessels are in close proximity. The enhancement of background tissue signals may also alter the arterial and venous temporal profiles in HYPR. However, the artifacts are manifest as intensity modulation rather than structural interference, and therefore have little impact on structural diagnosis. Increasing the number of projections per time point increases temporal blur while reducing corruption of temporal behavior from adjacent tissues. Uniformly interleaved acquisition order, such as the bit‐reversed order, is important to reduce artifacts. With high signal‐to‐noise ratio (SNR) and limited artifacts, HYPR reconstruction has potential to greatly improve time‐resolved MRA in clinical practice. Magn Reson Med 58:316–325, 2007. © 2007 Wiley‐Liss, Inc.
T1 relaxation in in vivo mouse brain at ultra‐high field
Authors: van de Ven Rob C.G. , Hogers Bianca , van den Maagdenberg Arn M.J.M. , de Groot Huub J.M. , Ferrari Michel D. , Frants Rune R. , Poelmann Robert E. , van der Weerd Louise , Kiihne Suzanne R.
Published: July 2007

Accurate knowledge of relaxation times is imperative for adjustment of MRI parameters to obtain optimal signal‐to‐noise ratio (SNR) and contrast. As small animal MRI studies are extended to increasingly higher magnetic fields, these parameters must be assessed anew. The goal of this study was to obtain accurate spin‐lattice (T1) relaxation times for the normal mouse brain at field strengths of 9.4 and 17.6 T. T1 relaxation times were determined for cortex, corpus callosum, caudate putamen, hippocampus, periaqueductal gray, lateral ventricle, and cerebellum and varied from 1651 ± 28 to 2449 ± 150 ms at 9.4 T and 1824 ± 101 to 2772 ± 235 ms at 17.6 T. A field strength–dependent increase of T1 relaxation times is shown. The SNR increase at 17.6 T is in good agreement with the expected SNR increase for a sample‐dominated noise regime. Magn Reson Med 58:390–395, 2007. © 2007 Wiley‐Liss, Inc.
A noniterative method to design large‐tip‐angle multidimensional spatially‐selective radio frequency pulses for parallel transmission
Authors: Xu Dan , King Kevin F. , Zhu Yudong , McKinnon Graeme C. , Liang Zhi‐Pei
Published: July 2007

Recently, theoretical and experimental work has shown that parallel transmission of RF pulses can be used to shorten the duration of multidimensional spatially‐selective pulses and compensate for B1 field inhomogeneity. However, all the existing noniterative methods can design only excitation pulses for parallel transmission with a small flip angle (e.g., 30°, or at most 90°) and cannot design large‐tip‐angle inversion/refocusing pulses, because these methods are based on the small‐tip‐angle (STA) approximation of the Bloch equation. In this work, a method to design large‐tip‐angle multidimensional spatially‐selective pulses for parallel transmission is proposed, based on an extension of the single‐channel linear‐class large‐tip‐angle (LCLTA) theory. Design examples of 2D refocusing and inversion parallel transmit pulses and magnetization profiles from Bloch equation simulations demonstrate the strength of the proposed method. A 2D spin‐echo parallel transmission experiment on a slab phantom using a 180° refocusing pulse with an eight‐channel transmit‐only array further validates the effectiveness of the proposed method. Magn Reson Med 58:326–334, 2007. © 2007 Wiley‐Liss, Inc.
Noninvasive diffusion tensor imaging of evolving white matter pathology in a mouse model of acute spinal cord injury
Authors: Kim Joong Hee , Loy David N. , Liang Hsiao‐Fang , Trinkaus Kathryn , Schmidt Robert E. , Song Sheng‐Kwei
Published: July 2007

We examined in vivo measurements of directional diffusivity derived from diffusion tensor imaging (DTI) to study the evolution of ventrolateral white matter (VWM) changes following contusive spinal cord injury (SCI) in C57BL/6 mice at 1, 3, 7, and 14 days postinjury. Relative anisotropy maps provided excellent gray matter (GM)/white matter (WM) contrast for characterization of evolving WM injury at all time points. Longitudinal DTI measurements clearly demonstrated rostral‐caudal injury asymmetry. Axial diffusivity provided a sensitive, noninvasive measure of axonal integrity within the injury epicenter and at remote levels. Quantitative measurements of axial and radial diffusivities in VWM showed a trend of acute primary axonal injury followed by delayed, subacute myelin damage at the impact site, with good histological correlation. Magn Reson Med 58:253–260, 2007. © 2007 Wiley‐Liss, Inc.
What levels of precision are achievable for quantification of perfusion and capillary permeability surface area product using ASL?
Authors: Carr John P. , Buckley David L. , Tessier Jean , Parker Geoff J.M.
Published: July 2007

We examine the use of arterial spin labeling (ASL) in normal brains of rats and humans to measure perfusion (F) and capillary permeability surface area product (PS) using a previously described two‐compartment model. We investigate the experimental limits on F and PS quantification using simulations and experimental verification in rat brain at 9.4T. A sensitivity analysis on the two‐compartment model is presented to estimate optimal experimental inversion times (TIs) for F and PS quantification and indicate how sensitive the model would be to changes in F and PS. We present the expected error on flow‐sensitive alternating inversion recovery (FAIR)‐based F and PS measurements and quantify the precision with which these parameters could be estimated at various signal‐to‐noise ratios (SNRs). Perfusion was measured in four rat brains using FAIR ASL, and we conclude that perfusion could be quantified with an acceptable level of precision using this technique. However, we found that to measure PS with even a 100% coefficient of variation (CV) would require an SNR increase of approximately 2 orders of magnitude over our acquired data. We conclude that with current MR capabilities and with the experimental approach used in this study, acceptable levels of precision in the measurement of PS are not possible. Magn Reson Med 58:281–289, 2007. © 2007 Wiley‐Liss, Inc.
Functional imaging with FENSI: Flow‐enhanced signal intensity
Authors: Sutton Bradley P. , Ouyang Cheng , Ching Bryce L. , Ciobanu Luisa
Published: July 2007

Flow measurement methods for functional MRI (fMRI) are desirable as they are more closely tied to neuronal activity than the commonly used blood oxygenation techniques. In this work we introduce a flow‐based functional imaging method. The method, called flow enhancement of signal intensity (FENSI), is an extension of the diffusion enhancement of signal and resolution (DESIRE) method from MR microscopy. The FENSI method offers a localized flow‐weighted signal across a very thin slice (0.4 mm in this study) that provides a signal enhancement that is dependent on the velocity and direction of the flow. The FENSI method was implemented on a human 3 T system and applied to a blocked visual cognitive task. Activation maps showed good localization and the measured signal changes of around 10% were in good agreement with the predicted enhancements. Magn Reson Med 58:396–401, 2007. © 2007 Wiley‐Liss, Inc.
Optimization of fast spiral chemical shift imaging using least squares reconstruction: Application for hyperpolarized 13C metabolic imaging
Authors: Levin Y.S. , Mayer D. , Yen Y.‐F. , Hurd R.E. , Spielman D.M.
Published: July 2007

A least‐squares–based optimization and reconstruction algorithm has been developed for rapid metabolic imaging in the context of hyperpolarized 13C. The algorithm uses a priori knowledge of resonance frequencies, J‐coupling constants, and T2* values to enable acquisition of high‐quality metabolic images with imaging times of approximately 100 ms for an 8‐cm field of view (FOV) and 0.5 cm isotropic resolution. A root‐mean‐square error (rMSE) analysis is introduced to optimize metabolic image quality by appropriate choice of pulse sequence parameters, echo times, and signal model. By performing the reconstruction in k‐space, the algorithm also allows the inclusion of the effect of chemical shift evolution during the readout period. Single‐interleaf multiecho spiral chemical shift imaging (spCSI) is analyzed in detail as an illustrative example for the use of the new reconstruction and optimization algorithm. Simulation of the in vivo spectrum following the bolus injection of hyperpolarized 13C1 pyruvate shows that single‐interleaf spiral spectroscopic imaging can achieve image quality in 100 ms, comparable to the performance of a 13‐s phase‐encoded chemical shift imaging (FIDCSI) experiment. Single‐interleaf spCSI was also tested at a 3‐T MR scanner using a phantom containing approximately 0.5‐M solutions of alanine, lactate, and a pyruvate‐pyruvate hydrate C1‐C2 ester at thermal equilibrium polarization, all enriched to 99% 13C in the C1 carbonyl positions. Upon reconstruction using the k‐space–based least‐squares technique, metabolite ratios obtained using the spCSI method were comparable to those obtained using a reference FIDCSI acquisition. Magn Reson Med 58:245–252, 2007. © 2007 Wiley‐Liss, Inc.
MRI estimation of contrast agent concentration in tissue using a neural network approach
Authors: Bagher‐Ebadian Hassan , Nagaraja Tavarekere N. , Paudyal Ramesh , Whitton Polly , Panda Swayamprava , Fenstermacher Joseph D. , Ewing James R.
Published: July 2007

Using an MRI T1 by multiple readout pulses (TOMROP) image set, an adaptive neural network (ANN) was trained to directly estimate the concentration of a contrast agent (CA), gadolinium‐bovine serum albumin (Gd‐BSA), in tissue. In nine rats implanted with a 9L cerebral tumor, MRI acquisition of TOMROP inversion‐recovery data was followed by quantitative autoradiography (QAR) using radioiodinated serum albumin (RISA). QAR autoradiograms were used as a training set for the ANN. Precontrast and 25 min postcontrast TOMROP image sets were shown to the ANN in the form of a physical feature set related to 24 inversion‐recovery images; QAR autoradiograms at 30 min after injection of RISA were taken as the training standard for the network. After training and optimization, the ANN produced a map of Gd‐BSA concentration [g‐moles/liter]. The prediction by the ANN of CA concentration at 25 min after injection was well correlated (r = 0.82, P < 0.0001) with the corresponding autoradiogram's measure of CA concentration. Magn Reson Med 58:290–297, 2007. © 2007 Wiley‐Liss, Inc.
Response of choline metabolites to docetaxel therapy is quantified in vivo by localized 31P MRS of human breast cancer xenografts and in vitro by high‐resolution 31P NMR spectroscopy of cell extracts
Authors: Morse David L. , Raghunand Natarajan , Sadarangani Pooja , Murthi Shiva , Job Constantin , Day Sam , Howison Christine , Gillies Robert J.
Published: July 2007

Choline‐containing compounds (CCCs) are elevated in breast cancer, and detected in vivo by the 1H MRS total choline (tCho) resonance (3.25 ppm) and the 31P MRS phosphomonoester (PME) resonance (3.8 ppm). Both the tCho and PME resonances decrease early after initiation of successful therapy. The single major component of these composite resonances, phosphocholine (PCho), also responds to therapy by decreasing. The ability to resolve and quantify PCho in vivo would thus increase the sensitivity of this biomarker for early detection of therapeutic response.Herein, the in vivo resolution and quantification of PCho is reported in human mouse xenograft tumors of the human breast cancer cell lines MCF‐7 and MDA‐mb‐231. Significant decreases in tumor PCho are observed within 2 to 4 d posttreatment with the antimicrotubule drug, docetaxel. To determine whether these decreases are a general tumor response or an intracellular metabolic response, high‐resolution NMR spectroscopy was performed on extracts of cells treated with docetaxel. Significant decreases in intracellular PCho and increases in glycerophosphocholine (GPC) were observed. These decreases are coincident with other tumor and cellular responses such as tumor growth delay (TGD), cell‐cycle arrest, and modes of cell death such as mitotic catastrophe, necrosis, and apoptosis, with mitotic catastrophe predominating. Magn Reson Med 58:270–280, 2007. © 2007 Wiley‐Liss, Inc.
On the identifiability of pharmacokinetic parameters in dynamic contrast‐enhanced imaging
Authors: Lopata Richard G.P. , Backes Walter H. , van den Bosch Paul P.J. , van Riel Natal A.W.
Published: July 2007

The so‐called “Kety model” is a two‐compartment pharmacokinetic model describing tumor perfusion kinetics. Its parameters, the transendothelial transfer constant (Ktrans), extravascular extracellular volume fraction (υe), and microvascular plasma volume fraction (υp), can be estimated with dynamic contrast‐enhanced magnetic resonance imaging (DCE‐MRI). However, the results obtained by current methods show large variation in predictability and reliability. Here, the aim was to examine which experimental conditions have to be fulfilled to avoid large uncertainties and mutual dependencies of the parameters. Using frequency response analysis and simulation, the identifiability of the model was examined. The requirements and influence of contrast enhancement measurements, such as temporal resolution, signal to noise ratio, and contrast injection rate, on the accuracy of the parameters were analyzed. Tissue response characteristics revealed a low‐frequency system with a cutoff frequency equal to Ktrans/υe, which confines the required temporal resolution. For malignant tissue with hyperpermeable vasculature (high Ktrans) a higher sampling frequency is required to accurately estimate Ktrans than for normal tissue. Too low sampling rates or too low injection rates resulted in inaccurate Ktrans values and hereby unreliable classification of malignant tissue. Magn Reson Med 58:425–429, 2007. © 2007 Wiley‐Liss, Inc.
Synemin expression in brain
Authors: Mizuno Yuji , Guyon Jeffrey R. , Okamoto Koichi , Kunkel Louis M.
Published: July 2007

β‐Synemin has been identified as an α‐dystrobrevin–interacting protein in human muscle, although at least two synemin transcripts are expressed in brain. To understand synemin's function in neural tissue, in situ and immunohistochemical analyses were performed to identify where α‐ and β‐synemin are expressed in the brain of C57BL/6 and mdx (dystrophin null) mice. This analysis shows that the α‐ and β‐synemin transcripts and their encoded proteins colocalize in neurons, especially in the midbrain and pons. Since α‐dystrobrevin‐1 and synemin do not colocalize in brain as in muscle, this suggests that another member of the dystrophin‐associated protein complex might interact with synemin in brain. In support of this, synemin mRNA expression was decreased in mdx mice, suggesting that synemin transcription is linked to dystrophin expression. Our findings show where synemin is expressed in brain and allow one to speculate with regard to its function in neural tissue. Muscle Nerve, 2007
Multiple measures of axonal excitability in peripheral sensory nerves: An in vivo rat model
Authors: George Annette , Bostock Hugh
Published: July 2007

Excitability measurements on human motor and sensory nerves have provided new insights into axonal membrane changes in peripheral nerve disorders. The aim of this study was to establish an in vivo rat preparation suitable for threshold tracking of sensory nerve action potentials (SNAPs) to model clinical sensory nerve excitability studies. In Sprague–Dawley rats anesthetized with ketamine and xylazine, current stimuli were applied to the base of the tail and SNAPs recorded from distal needle electrodes. Multiple excitability data were obtained as previously described for human nerves and compared to recordings from the motor tail axons and to sensory recordings from human median and ulnar nerves. The pattern of excitability changes in rats was broadly similar to that in humans, although some parameters differed significantly. Individual recordings were stable for at least 3 h. These data show that the rat tail enables excitability properties of sensory as well as motor axons to be studied experimentally, e.g., in models of nerve disease and during pharmacological interventions. Muscle Nerve, 2007
Comparative efficacy of repetitive nerve stimulation, exercise, and cold in differentiating myotonic disorders
Authors: Michel Patrik , Sternberg Damien , Jeannet Pierre‐Yves , Dunand Murielle , Thonney Francine , Kress Wolfram , Fontaine Bertrand , Fournier Emmanuel , Kuntzer Thierry
Published: July 2007

The decremental response of the compound muscle action potential (CMAP) to provocative tests is not characterized in genetically verified myotonic disorders. We therefore studied the relationship between decremental responses and mutation type in 10 patients with recessive myotonia congenita (rMC), two with paramyotonia congenita (PMC), nine with myotonic dystrophy type 1 (DM1), four with DM2, and 14 healthy people. CMAPs were measured at rest, just after a short exercise test (SET), and during short, 5‐ and 10‐HZ, repetitive nerve stimulation (RNS) trains at 32°C and at 20°C. The degree of decrement was not related to the severity of clinical myotonia. Controls and PMC patients had similar responses when warm, but with cooling PMC patients had a persistent decrement of CMAPs. In the rMC patients the decremental responses were related to the type of mutation of the CLCN1 gene, as a decrement was encountered in the T268M, R894X, IVS17+1 G>T, K248X, and 2149 del G, but not with the IVS1+3 A>T, F167L, or dominant A313T mutations. In DM1 patients there was no relationship between decrement and CTG repeats. The degree of partial inexcitability in myotonic muscle membrane therefore depends on the mutation type rather than degree of clinical myotonia. RNS at 10 HZ is more sensitive than SET for demonstrating abnormalities in rMC patients when warm; differences are less marked when cold, which is useful to diagnose PMC. Provocative tests are therefore useful in myotonias to demonstrate muscle inexcitability, which depends on the chloride or sodium channelopathy. Muscle Nerve, 2007
Inflections in threshold electrotonus to depolarizing currents in sensory axons
Authors: Burke David , Howells James , Trevillion Louise , Kiernan Matthew C. , Bostock Hugh
Published: July 2007

Threshold electrotonus involves tracking the changes in axonal excitability produced by subthreshold polarizing currents and is the only technique that allows insight into the function of internodal conductances in human subjects in vivo. There is often an abrupt transient reversal of the threshold change as excitability increases in response to conditioning depolarizing currents (S1 phase). In recordings from motor axons, it has been recently demonstrated that this notch or inflection is due to activation of low‐threshold axons. We report that a notch is frequently seen in sensory recordings (in 33 of 50 healthy subjects) using the standard threshold electrotonus protocol. When large, the notch can distort subsequent phases of threshold electrotonus and could complicate quantitative measurements and modeling studies. Muscle Nerve, 2007
Finite element analyses of layered visco‐elastic system under vertical circular loading
Authors: Xu Q. , Rahman M. S.
Published: July 2007

Analyses for the response of a linear visco‐elastic system subjected to axi‐symmetric vertical circular loading are presented. Hankel transforms with respect to the radial spatial coordinate are used to reduce the three‐dimensional problem to that involving only a single spatial dimension, which is then discretized using the finite element method. Three techniques are employed to handle the time factor in the visco‐elastic material: (i) direct time integration; (ii) Fourier transforms; and (iii) Laplace transforms. These methods are compared and evaluated through their numerical results. Copyright © 2007 John Wiley & Sons, Ltd.
Some results about f‐critical graphs
Authors: Liu Guizhen , Hou Jianfeng , Cai Jiansheng
Published: July 2007

An f‐coloring of a multigraph G is a coloring of the edges of E such that each color appears at each vertex v ∈ V at most f(v) times. The minimum number of colors needed to f‐color G is called the f‐chromatic index of G and is denoted by χ′f(G). Various scheduling problems on networks are reduced to finding an f‐coloring of a multigraph. Any simple graph G has f‐chromatic index equal to Δf(G) or Δf(G)+ 1, where Δf(G) = max v∈V{⌈
${d(v)\over f(v)}$⌉} and d(v) is the degree of vertex v. A connected graph G is called f‐critical if χ′f(G)=Δf(G)+1 and χ′f(G)=Δf(G−e) < χ′f(G) for any edge e ∈ E. Some results about f‐critical graphs are given. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(3), 197–202 2007
The vehicle rescheduling problem: Model and algorithms
Authors: Li Jing‐Quan , Mirchandani Pitu B. , Borenstein Denis
Published: July 2007

When a vehicle on a scheduled trip breaks down, one or more vehicles need to be rescheduled to serve the customers on that trip with minimum operating and delay costs. The problem of reassigning vehicles in real‐time to this cut trip as well as to other scheduled trips with given starting and ending times, is referred to as the vehicle rescheduling problem (VRSP). This paper considers modeling, algorithmic, and computational aspects of the single‐depot VRSP. The paper formulates a model for this problem and develops several fast algorithms to solve it, including parallel synchronous auction algorithms. The concept of the common feasible network (CFN) is introduced to find a good set of initial “prices” for speeding up the auction algorithm. Computational experiments on randomly generated problems are described. Computational results show that, for small problems, all of the developed algorithms demonstrate very good computational performances. For large problems, parallel CFN‐based auction algorithms provide the optimal solution with much smaller computation times. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 50(3), 211–229 2007
A meta‐analysis of studies of nurses' job satisfaction
Authors: Zangaro George A. , Soeken Karen L.
Published: July 2007

Although several variables have been correlated with nursing job satisfaction, the findings are not uniform across studies. Three commonly noted variables from the nursing literature are: autonomy, job stress, and nurse–physician collaboration. This meta‐analysis examined the strength of the relationships between job satisfaction and autonomy, job stress, and nurse–physician collaboration among registered nurses working in staff positions. A meta‐analysis of 31 studies representing a total of 14,567 subjects was performed. Job satisfaction was most strongly correlated with job stress (ES = −.43), followed by nurse–physician collaboration (ES = .37), and autonomy (ES = .30). These findings have implications for the importance of improving the work environment to increase nurses' job satisfaction. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:445–458, 2007.
Wellness motivation in cardiac rehabilitation: The role of self‐knowledge in cardiovascular risk modification
Authors: Fleury Julie , Sedikides Constantine
Published: July 2007

Understanding the factors that motivate behavioral change is central to health promotion efforts. We used qualitative descriptive methods in an effort to understand the role of self‐knowledge in the process of risk factor modification. The sample consisted of 17 men and 7 women with diagnosed coronary heart disease, who were attempting to initiate and sustain programs of cardiovascular risk modification. Participants described self‐knowledge in terms of three contextually situated patterns: representational, evaluative, and behavioral action. Results reinforce the motivational role of the self and highlight the importance of understanding dimensions of self‐knowledge relevant to cardiovascular risk reduction. © 2007 Wiley Periodicals, Inc. Res Nurs Health 30:373–384, 2007.
High‐performance liquid chromatographic separation and identification of polyphenolic compounds from the infusion of Davilla elliptica St. Hill
Authors: Rodrigues Clenilson M. , Rinaldo Daniel , Sannomiya Miriam , Santos Lourdes C. dos , Montoro Paola , Piacente Sonia , Pizza Cosimo , Vilegas Wagner
Published: July 2007

The isolation of polyphenolic compounds from an infusion of the Brazilian plant Davilla elliptica (Dilleniaceae), used as tea by virtue of its digestive properties, is described. An improved preparative HPLC method was used in order to isolate pure polyphenols from the complex mixture. Liquid–liquid extraction and solid‐phase extraction were employed to minimise the interference of polymeric compounds and to provide an enriched fraction of the compounds of interest. The identification of the isolated compounds was performed using analytical HPLC as well as direct injection electrospray ionisation ion trap tandem mass spectrometry (ESI‐IT‐MS/MS). The high flavonoid content suggests that D. elliptica may be a promising source of compounds to produce natural phytomedicines. Copyright © 2007 John Wiley & Sons, Ltd.
Preparative separation of four triterpene saponins from radix astragali by high‐speed counter‐current chromatography coupled with evaporative light scattering detection
Authors: Peng Jinyong , Dong Fuqiu , Qi Yan , Han Xu , Xu Youwei , Xu Lina , Xu Qiwei , Liu Kexin , Zhu Zhenyu
Published: July 2007

Four triterpene saponins, including astragaloside IV, astragaloside II, astragaloside I and acetylastragaloside I, were successfully isolated and separated by high‐speed counter‐current chromatography coupled with evaporative light scattering detection from Radix Astragali using stepwise elution with a pair of solvent systems composed of n‐hexane:ethyl acetate:ethanol:water in volume ratios of 1:0.6:0.6:1 and 1:1:1:1 (by volume). The isolation produced 26.5 mg astragaloside IV, 28.2 mg astragaloside II, 48.7 mg astragaloside I and 17.6 mg acetylastragaloside I with purities of 97.6, 96.4, 98.8 and 96.8%, respectively, determined by high‐performance liquid chromatography from 250 mg crude extract. The chemical structures of the isolated compounds were identified by UV, NMR and MS, and confirmed by authentic standards. Copyright © 2007 John Wiley & Sons, Ltd.
In‐gel detection of urease activity by nitroprusside–thiol reaction
Authors: Sharma Vineet , Chaudhary Rajesh , Khurana J. M. , Muralidhar K.
Published: July 2007

A new staining method for urease activity in non‐denaturing polyacrylamide gels is described. The increase in local pH of the gel, resulting from ureolytic activity of urease, causes a purple red coloured band after incubation of the polyacrylamide gel with urea. Staining of urease activity using this method is very specific for catalytically active urease even in crude preparations. Detection of urease activity by this method is rapid, simple and economical. The described method is also more sensitive than existing methods of urease staining. A minimum of 0.25 mU of urease activity can be detected after 5 min of incubation with the substrate. The method has been used to demonstrate the presence of different charge isoforms of urease in a member of the plant family Cucurbitaceae. Copyright © 2007 John Wiley & Sons, Ltd.
Simultaneous quantification of five triterpenoid saponins in Clematis L. Spp. by high‐performance liquid chromatography with evaporative light scattering detection
Authors: Sun Feng , He Qing , Xiao Peigen , Muhammad Ishtiaq , Cheng Yiyu
Published: July 2007

A simple and accurate method involving high‐performance liquid chromatography with evaporative light scattering detection was developed for the simultaneous determination of five triterpenoid saponin components in Clematis L. spp. for the first time. The analysis was performed on a Zorbax SB‐C18 column and gradient elution with acetonitrile and water with 0.1% formic acid was utilised. All the calibration curves exhibited good linear characteristics with correlation coefficients in the range from 0.9979 to 0.9997. The limits of detection and limits of quantification were less than 0.152 and 0.506 µg, respectively. The overall recoveries for the five analytes were between 91.3 and 99.5%. A total of 10 samples from Clematis L. spp. were analysed under optimised conditions and the chemical profiles provided information for the identification of botanical origin, the development of new medicinal resources and chemotaxonomic investigation. Copyright © 2007 John Wiley & Sons, Ltd.
Primary flavonoids in marigold dye: extraction, structure and involvement in the dyeing process
Authors: Guinot Pauline , Gargadennec Annick , Valette Gilles , Fruchier Alain , Andary Claude
Published: July 2007

Flavonoids extracted from marigold flowers were investigated for their dyeing potential. Patulitrin (1) and patuletin (2) were isolated and their structures established using NMR and HPLC‐MS. These compounds were identified as the main flavonoids present in the dyeing bath. Following the dyeing process, it was demonstrated that aglycone 2 bound more strongly to wool fibres than its glucoside 1. Moreover, analysis focused on 1 and 2 dynamics during plant growth revealed that these components were only found in flowers during and after flowering. The influence of growing location was also investigated and it appeared that cultivation under Mediterranean conditions enhanced biosynthesis of 1 and 2 . Finally, several solvents were tested for their potential to extract the flavonoids: the use of a water–ethanol mixture gave a high extraction efficiency and allowed selective extraction of 1 and 2. The implications of these results are discussed in relation to the development of marigold as a potential dyeing plant. Copyright © 2007 John Wiley & Sons, Ltd.
Proteome of mesenchymal stem cells
Authors: Park Hye Won , Shin Jun‐Seop , Kim Chan‐Wha
Published: July 2007

Proteomics has evolved, in recent years, into effective tools for basic and applied stem cell research, and has been extensively used to facilitate the identification of changes in signal transduction components, especially with regard to plasticity, proliferation, and differentiation. Several recent reports have also employed proteomic strategies to characterize human mesenchymal stem cells (hMSC) and their differentiated derivatives. Although these approaches have yielded valuable data, the results highlight the fact that only the limited numbers of proteins are characterized at the protein level in these cells, thus necessitating expandable MSC proteome dataset. This review presents, for the first time, an expandable list of MSC proteins, which will function as a starting point for the generation of a comprehensive reference map of their proteome. Also, the better way to bridge current gap between genomics and proteomics study such as integrated proteomic and transcriptomic analyses is discussed.
Mammalian plasma membrane proteomics
Authors: Josic Djuro , Clifton James G.
Published: July 2007

Plasma membrane proteins serve essential functions for cells, interacting with both cellular and extracellular components, structures and signaling molecules. Additionally, plasma membrane proteins comprise more than two‐thirds of the known protein targets for existing drugs. Consequently, defining membrane proteomes is crucial to understanding the role of plasma membranes in fundamental biological processes and for finding new targets for action in drug development. MS‐based identification methods combined with chromatographic and traditional cell‐biology techniques are powerful tools for proteomic mapping of proteins from organelles. However, the separation and identification of plasma membrane proteins remains a challenge for proteomic technology because of their hydrophobicity and microheterogeneity. Creative approaches to solve these problems and potential pitfalls will be discussed. Finally, a representative overview of the impressive achievements in this field will also be given.
Public proteomic MS repositories and pipelines: available tools and biological applications
Authors: Mead Jennifer A. , Shadforth Ian P. , Bessant Conrad
Published: July 2007

As proteomic MS has increased in throughput, so has the demand to catalogue the increasing number of peptides and proteins observed by the community using this technique. As in other ‘omics’ fields, this brings obvious scientific benefits such as sharing of results and prevention of unnecessary repetition, but also provides technical insights, such as the ability to compare proteome coverage between different laboratories, or between different proteomic platforms. Journals are also moving towards mandating that proteomics data be submitted to public repositories upon publication. In response to these demands, several web‐based repositories have been established to store protein and peptide identifications derived from MS data, and a similar number of peptide identification software pipelines have emerged to deliver identifications to these repositories. This paper reviews the latest developments in public domain peptide and protein identification databases and describes the analysis pipelines that feed them. Recent applications of the tools to pertinent biological problems are examined, and through comparing and contrasting the capabilities of each system, the issues facing research users of web‐based repositories are explored. Future developments and mechanisms to enhance system functionality and user‐interfacing opportunities are also suggested.
Proteoglycanomics: tools to unravel the biological function of glycosaminoglycans
Authors: Gesslbauer Bernd , Rek Angelika , Falsone Fabio , Rajkovic Erich , Kungl Andreas J.
Published: July 2007

Glycosylation is the most frequent PTM and contributes significantly to the function of proteins depending on the type of glycosylation. Especially glycan structures like the glycosaminoglycans are considered to constitute themselves the major function of the glycoconjugate which is therefore termed proteoglycan. Here we review recent views on and novel tools for analysing the proteoglycanome, which are directly related to the type of glycanation under investigation. We define the major function of the proteoglycanome to be its interaction with various proteins in many different (patho‐)physiological conditions. This is exemplified by the differential glycosaminoglycan‐interactome of healthy versus arthritic patient sera.
Bayesian methods for proteomics
Authors: Alterovitz Gil , Liu Jonathan , Afkhami Ehsan , Ramoni Marco F.
Published: July 2007

Biological and medical data have been growing exponentially over the past several years [1, 2]. In particular, proteomics has seen automation dramatically change the rate at which data are generated [3]. Analysis that systemically incorporates prior information is becoming essential to making inferences about the myriad, complex data [4–6]. A Bayesian approach can help capture such information and incorporate it seamlessly through a rigorous, probabilistic framework. This paper starts with a review of the background mathematics behind the Bayesian methodology: from parameter estimation to Bayesian networks. The article then goes on to discuss how emerging Bayesian approaches have already been successfully applied to research across proteomics, a field for which Bayesian methods are particularly well suited [7–9]. After reviewing the literature on the subject of Bayesian methods in biological contexts, the article discusses some of the recent applications in proteomics and emerging directions in the field.
Transient absorption investigation of the photophysical properties of new photochromic 3H‐naphtho[2,1‐b]pyran
Authors: Moine B. , Buntinx G. , Poizat O. , Rehault J. , Moustrou C. , Samat A.
Published: July 2007

The photophysical and photochemical properties of two 3,3‐diphenyl‐3H‐naphtho[2,1‐b]pyrans substituted in position 8 by phenylethynyl and p‐nitrophenylethynyl groups, respectively, are investigated by femtosecond and nanosecond transient absorption spectroscopy. The spectral characteristics and dynamics of the lowest excited singlet and triplet states are determined. The ring‐opening reaction responsible for the photochromism is observed to occur in the S1 state. Copyright © 2007 John Wiley & Sons, Ltd.
Characterization of electron beam irradiation blends based on metallocene ethylene‐1‐octene copolymer
Authors: Cárdenas Miguel Angel , Villarreal Norky , Gobernado‐Mitre Isabel , Merino Juan Carlos , Pastor José María
Published: July 2007

Binary blends using metallocene ethylene‐1‐octene copolymer as matrix were prepared and subjected to electron beam (EB) irradiation (50, 100, and 200 kGy). Gel content and melt flow index values indicated that the blends were crosslinking. Fourier transform infrared‐ATR spectroscopy was used to study the crosslinking and oxidative degradation of the blends via tertiary carbon and carboxyl group formation, respectively. Thermal and mechanical properties were studied showing that the crystallinity of both matrix and dispersed phase decreased with irradiation dose, and that the thermoplastic elastomers with good mechanical properties may be obtained by EB irradiation. Chain branching and scission were also detected at all irradiation doses, although at the highest doses (200 kGy) a crosslinking reaction was the most predominantly observed effect. The successive self‐nucleation annealing technique was used to determine the EB irradiation effects on crystallization of some blends in which crosslinking and chain branching take place, modifying the chain's structure and therefore crystalline regions in the matrix and the dispersed phase. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2432–2440, 2007
High melting thermoplastic/epoxy resin blends: Influence of the curing reaction on the crystallization and melting behavior
Authors: Goossens S. , Groeninckx G.
Published: July 2007

The influence of the cure process and the resulting reaction‐induced phase separation (RIPS) on the crystallization and melting behavior of polyoxymethylene (POM) in epoxy resin diglycidylether of bisphenol A (DGEBA) blends has been studied at different cure temperatures (180 and 145 °C). The crystallization and melting behavior of POM was studied with DSC and the simultaneous blend morphology changes were studied using OM. At first, the influence of the epoxy monomer on the dynamically crystallized POM was investigated. Secondly, a cure temperature above the melting point of POM (Tcure = 180 °C) was applied for blends with curing agent to study the influence of resulting phase morphology types on the crystallization behavior of POM in the epoxy blends. Large differences between particle/matrix and phase‐inverted structures have been observed. Thirdly, the cure temperature was lowered below the melting temperature of POM, inducing isothermal crystallization prior to RIPS. As a consequence, a distinction was made between dynamically and isothermally crystallized POM. Concerning the dynamically crystallized material, a clear difference could be made between the material crystallized in the homogeneous sample and that crystallized in the phase‐separated structures. The isothermally crystallized POM was to a large extent influenced by the conversion degree of the epoxy resin. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2456–2469, 2007
Clinical correlations and pulmonary function at 8 years of age after severe neonatal respiratory failure
Authors: Majaesic Carina M. , Jones Richard , Dinu Irina A. , Montgomery Mark D. , Sauve Reginald S. , Robertson Charlene M.T.
Published: July 2007

Objectives:

The aim of this study was to determine the pulmonary sequelae of severe neonatal respiratory failure.

Study Design:

This was a multicenter, prospective study. Fifty‐four survivors of neonatal respiratory failure (oxygenation indices >25 on two occasions), completed pulmonary function testing at 8 years of age. Thirty‐one (57%) received extracorporeal membrane oxygenation (ECMO). Pulmonary outcome was based on spirometry and lung volume data. Pulmonary outcome for each diagnostic and treatment group is reported as mean and as percent predicted. Individually subjects were also classified based on spirometry, as either normal, obstructed (defined as forced expiratory volume (FEV1) in 1 sec:forced vital capacity (FVC) of <80 % predicted, or with reduced FVC (FCV of <80% predicted) with normal FEV1/FVC. Risk for adverse outcome was determined using univariate analysis.

Results:

Mean FVC, FEV1 and FEV25–75 were reduced in the total cohort. The reduction was greatest in the subgroup with CDH and the group treated with ECMO. Assessed individually, 54% of subjects had normal spirometry and lung volumes, 19% airflow obstruction, and 27% reduced FVC. Poorer pulmonary outcome was linked to ECMO, congenital diaphragmatic hernia (CDH), birth weight for gestational age <10th percentile, duration of hospitalization, or need for prolonged supplemental oxygen.

Conclusion:

Neonates with severe respiratory failure due to CDH or needing ECMO and small for gestation are at increased risk of poorer pulmonary outcome and require close follow‐up. Pediatr Pulmonol. 2007; 42:829–837. © 2007 Wiley‐Liss, Inc.
Human kallikrein‐related peptidase 12: Antibody generation and immunohistochemical localization in prostatic tissues
Authors: Memari Nader , Diamandis Eleftherios P. , Earle Tammy , Campbell Alison , Van Dekken Herman , Van der Kwast Theodore H.
Published: July 2007

Background

Human tissue kallikrein‐related peptidases (genes, KLKs; proteins, KLKs) are a subgroup of serine proteases present in a variety of tissues and biological fluids. A number of human tissue KLKs are established or candidate serologic biomarkers for prostate cancer. Human kallikrein‐related peptidase 12 (KLK12, KLK12), recently identified in our laboratory, is a novel member of the KLK gene family. Here, we report generation of antibodies against the full‐length recombinant KLK12 (classical form) and the immunohistological localization of this KLK in normal and malignant prostate tissues.

Methods

The mature form of KLK12 cDNA was amplified using PCR and cloned into a plasmid vector for protein production in E. coli. Following identification by mass spectroscopy, recombinant KLK12 was purified and used as immunogen in rabbits. Anti‐ KLK12 antibody was used for immunostaining of paraffin‐embedded sections of human prostate tissue. Immunoexpression of KLK12 in benign and malignant prostate tissue was evaluated using a prostate cancer tissue array.

Results

Anti‐KLK12 antibody showed a predominantly apical and membranous staining of the luminal cells of the normal prostate in contrast with the predominantly diffuse cytoplasmic staining observed in both prostatic intra‐epithelial neoplasia and adenocarcinomas. This was occasionally associated with an intense granular supranuclear staining. More than 95% of the prostate cancers on the tissue microarray were KLK12 positive.

Conclusion

Higher levels of KLK12 in malignant prostatic glands, and the shift in subcellular localization of KLK12 in prostate cancer observed in this study point to the potential role of this kallikrein during prostate carcinogenesis. Prostate 67: 1465–1474, 2007. © 2007 Wiley‐Liss, Inc.
Statistical recombinant mapping in extended high‐risk Utah pedigrees narrows the 8q24 prostate cancer locus to 2.0 Mb
Authors: Camp Nicola J. , Farnham James M. , Allen‐Brady Kristina , Cannon‐Albright Lisa A.
Published: July 2007

Background

Chromosome 8q24 is a region of compelling interest for prostate cancer (PRCA). Linkage, association, and admixture analysis initially indicated the region. Subsequently, several variants at 8q24 have been found to independently associate with PRCA. One compelling hypothesis is allelic heterogeneity, whereby multiple variants affect the regulation of the same gene. In addition to potential allelic heterogeneity, 8q24 exhibits strong linkage disequilibrium over vast distances and is prone to chromosomal aberrations.

Methods

Allelic heterogeneity and complex chromosomal structure are factors that hinder progress towards gene identification using association. Linkage techniques, however, are robust to allelic heterogeneity and therefore can contribute important localization information. We have used a linkage‐based localization technique to perform recombinant mapping in eight high‐risk Utah pedigrees.

Results

Using pedigree‐based recombinant mapping we identify a 5.7 Mb region at 8q24.21–22, between markers D8S1774 and D8S557. Considering our region with the localization previously presented, we can delimit the 8q24 PRCA locus to a 2.0 Mb consensus interval from 127.5 to 129.5 Mb.

Conclusion

We have used a linkage‐based, recombinant mapping technique in extended high‐risk Utah pedigrees to successfully narrow the 8q24 PRCA locus. The region we present halves the 95% credible interval previously described using admixture analysis and contains only three annotated genes: FAM84B, MYC, and TMEM75. It should be noted that LD stretches far beyond the interval we describe, and hence this region adds important information about where to focus future efforts to isolate the causal variants and underlying gene, whether by linkage or association techniques. Prostate 67: 1456–1464, 2007. © 2007 Wiley‐Liss, Inc.
Therapeutic integration of c‐myc and bcl‐2 antisense molecules with docetaxel in a preclinical model of hormone‐refractory prostate cancer
Authors: Leonetti Carlo , Biroccio Annamaria , D'Angelo Carmen , Semple Sean. C. , Scarsella Marco , Zupi Gabriella
Published: July 2007

Background

The response of hormone‐refractory prostate cancer (HRPC) to chemotherapy remains modest, necessitating the search for new forms of treatment to improve the prognosis. Since an increased expression of oncogenes, including c‐myc and bcl‐2, accompanies the transition to HRPC, we evaluated whether the concomitant downregulation of these oncogenes by antisense strategy sensitized HRPC to chemotherapy.

Methods

PC‐3 prostate cancer cells were exposed in vitro to c‐myc (INX‐6295) and bcl‐2 (G3139) antisense oligodeoxynucleotides (ODNs) and docetaxel given alone or in combination. Therapeutic efficacy of the different treatments was also evaluated in xenografts.

Results

We show that the triple combination of drugs given in the sequence G3139/docetaxel/INX‐6295 was the most active in reducing the survival of PC‐3. Likewise, the combination triggered apoptosis in more than 80% of cells. A marked tumor weight inhibition was observed in PC‐3 xenografts after G3139/docetaxel/INX‐6295 treatment, with a complete tumor regression being noted in half the mice. A 111% overall increase in life survival and a complete cure in two out of eight mice was also reported. This treatment remained effective even when started at a very late stage of tumor growth producing about 80% tumor weight inhibition (TWI), with tumor regression being maintained for 1 month. Finally, the antitumor effect resulted in a significant increase (70%) in mice survival.

Conclusions

These data indicate that the combined targeting of genes involved in uncontrolled proliferation and evasion of apoptosis renders HRPC responsive to chemotherapy making this treatment a promising antineoplastic strategy. Prostate 67: 1475–1485, 2007. © 2007 Wiley‐Liss, Inc.