bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of aging or left ventricular hypertrophy on the human heart: Contents of phosphorus metabolites measured by 31P MRS
Authors: Okada Mamoru , Mitsunami Kenichi , Inubushi Toshiro , Kinoshita Masahiko 
Published: March 2007

AbstractAlthough both aging and hypertrophy are extremely important factors for cardiac performance, their influence on cardiac metabolism, especially that of high‐energy phosphates, has not been fully elucidated as yet. Quantitative measurements of high‐energy phosphates were attempted by comparing myocardial 31P NMR spectra with an external reference using depth‐resolved surface‐coil spectroscopy. The voxel size of the region of interest (ROI) was disk‐shaped with 15‐cm diameter and 25‐mm thickness, but the left ventricular weight actually involved in the ROI was estimated to be between 22 and 66 g using MRI. Myocardial phosphocreatine (PCr) content and adenosine triphosphate (ATP) content for the 30 normal volunteers showed significant age dependence since both decreased in relation to increasing age. Myocardial PCr content and ATP content in patients with hypertension did not differ significantly from the age‐matched control group. PCr content (6.1 ± 2.2 μmol/g wet tissue, n=10) and ATP content (4.1 ±1.3 μmol/g wet tissue) in patients with hypertrophic cardiomyopathy were less than the age‐matched control group (n = 15; PCr: 9.7 ± 2.5 μmol/g wet tissue, P <0.01; ATP: 6.4 ±1.8 μmol/g wet tissue, P <0.05), respectively. These results indicate that quantitative 31P MRS may be valuable in the assessment of changes in high‐energy phosphate metabolism caused by aging or hypertrophy.
Quantitative assessment of bone marrow hematopoiesis using parametric magnetic resonance imaging
Authors: Ballon Douglas , Jakubowski Ann A. , Tulipano Paola K. , Graham Martin C. , Schneider Erika , Aghazadeh Behzad , Chen Qin‐Sheng , Koutcher Jason A. 
Published: March 2007

AbstractSpatial maps of the percentage cellularity in pelvic bone marrow were calculated at a resolution of 15.6 mm3 from six volunteers and 10 patients treated for documented hematologic disease using a three‐point Dixon MRI pulse sequence. The percentage cellularity calculation was aided by analyzing a two‐dimensional feature space consisting of the apparent water fraction (Wa), and the T2 relaxation time of water (T2w). An extracellular water fraction was assigned to each voxel on the basis of a two‐component T2w algorithm. In six cases, the method was compared to results obtained from core biopsies or aspirates of the posterior iliac crest. The results indicate that segmentation schemes that combine high‐quality phase‐contrast imaging with nuclear relaxation time measurements can potentially identify the true fractional marrow volume occupied by hematopoietic elements in a variety of clinical situations.
Pattern recognition analysis of 1H NMR spectra from perchloric acid extracts of human brain tumor biopsies
Authors: Maxwell Ross J. , Martínez‐Pérez Irene , Cerdán Sebastián , Cabañas Miquel E. , Arús Carles , Moreno Àngel , Capdevila Antoni , Ferrer Enrique , Bartomeus Frederic , Aparicio Alberto , Conesa Gerard , Roda José María , Carceller Fernando , Pascual José María , Howells Siǎn L. , Mazucco Roy , Griffiths John R. 
Published: March 2007

AbstractPattern recognition techniques (factor analysis and neural networks) were used to investigate and classify human brain tumors based on the 1H NMR spectra of chemically extracted biopsies (n = 118). After removing information from lactate (because of variable ischemia times), unsupervised learning suggested that the spectra separated naturally into two groups: meningiomas and other tumors. Principal component analysis reduced the dimensionality of the data. A back‐propagation neural network using the first 30 principal components gave 85% correct classification of meningiomas and nonmeningiomas. Simplification by vector rotation gave vectors that could be assigned to various metabolites, making it possible to use or to reject their information for neural network classification. Using scores calculated from the four rotated vectors due to creatine and glutamine gave the best classification into meningiomas and nonmeningiomas (89% correct). Classification of gliomas (n = 47) gave 62% correct within one grade. Only inositol showed a significant correlation with glioma grade.
Magnetic resonance microimaging for noninvasive quantification of myocardial function and mass in the mouse
Authors: Ruff Jan , Wiesmann Frank , Hiller Karl‐Heinz , Voll Sabine , von Kienlin Markus , Bauer Wolfgang R. , Rommel Eberhard , Neubauer Stefan , Haase Axel 
Published: March 2007

AbstractThe purpose of this work was to develop high‐resolution cardiac magnetic resonance imaging techniques for the in vivo mouse model for quantification of myocardial function and mass. Eight male mice were investigated on a 7‐Tesla MRI scanner. High‐quality images in multiple short axis slices (in‐plane resolution 117 μm2, slice thickness 1 mm) were acquired with an ECG‐gated cine sequence. Left ventricular end‐diastolic and end‐systolic volumes and mass were calculated from segmented slice volumes. There was precise agreement of left ventricular mass determined ex vivo and by MRI. lntraobserver (5%) and interobserver (5%) variability of in vivo MR measurements were low.
A spiral volume coil for improved RF field homogeneity at high static magnetic field strength
Authors: Alsop David C. , Connick Thomas J. , Mizsei Gabor 
Published: March 2007

AbstractBiological samples have a high dielectric constant that can shorten RF wavelengths by a factor of 8 relative to the vacuum. At high field strengths, finite wavelength effects within larger samples are the dominant cause of RF field nonunifor‐mity. A coil design is presented that can reduce and even eliminate this inhomogeneity; 4‐T images in phantoms and in the head of a normal volunteer are presented, which demonstrate improved homogeneity relative to a standard coil. This coil design should aid in realizing the potential advantages of imaging large samples at high field strengths.
Magnetic field changes in the human brain due to swallowing or speaking
Authors: Birn Rasmus M. , Bandettini Peter A. , Cox Robert W. , Jesmanowicz Andrzej , Shaker Reza 
Published: March 2007

AbstractVariations in the magnetic field in the human brain caused by the processes of swallowing or speaking are measured. In both processes, motion of the pharyngeal muscles, especially the tongue and jaw, alter the susceptibility‐induced magnetic field distribution at the brain slice being imaged. This leads to image warping, compromising the analysis of a time series of images, such as in functional magnetic resonance imaging (fMRI). These dynamic changes are assessed by acquiring a time series of images using a gradient‐echo asymmetric‐spin‐echo sequence (GREASE), a technique in which two images are acquired for each excitation–one during the gradient echo, and one during the latter part of the spin echo. The NMR phase difference between the two images is a measure of the magnetic field distribution. A series of brain images, acquired with this sequence while the subject either swallows or speaks, indicated negative magnetic field changes of up to O.087 ppm in the inferior region of the brain for both speaking and swallowing, and in some speech, additional positive changes of up to O.056 ppm in the frontal region of the brain were indicated.
Integrated analysis of diffusion and relaxation of water in blood
Authors: Li Jonathan G. , Stanisz Greg J. , Henkelman R. Mark 
Published: March 2007

AbstractDiffusion and T2 relaxation of water both inside and outside red blood cells (RBCs) in human blood were investigated using a hybrid NMR pulse sequence to obtain a more quantitative understanding of the diffusion and relaxation behavior of water in paramagnetic‐doped blood samples. The data were analyzed by both examining the relaxation properties of the system after each diffusion weighting and looking at the diffusion properties at each echo time. The results illustrate how diffusion‐sensitizing gradients affect the T2 spectra of blood and how relaxation weighting changes the curvature of the diffusion curves, thereby demonstrating the close coupling between diffusion and T2 relaxation. A three‐pool model, consisting of RBCs, plasma, and macromolecular protons, was used to model the data from the diffusion‐relaxation hybrid experiments. The model was found to describe all the characteristic features of the experimental data well and was used to evaluate the approximations involved in the conventional analysis methods and elucidate the nature of the relaxing and diffusing components. Compared with the separate diffusion and relaxation experiments, the diffusion‐relaxation hybrid experiments are less time‐consuming, result in better parameter determinations, and may be useful in analyzing diffusion‐T2 coupling in tissues with more complicated multi‐exponential T2 behavior.
Proteomic analysis of Burkholderia cepacia MBA4 in the degradation of monochloroacetate
Authors: Kwok Sui‐Yi , Siu Annie Fung‐Ming , Ngai Sai‐Ming , Che Chi‐Ming , Tsang Jimmy S. H. 
Published: March 2007

AbstractBurkholderia cepacia MBA4 is a bacterium that degrades 2‐haloacids by removing the halogen and subsequent metabolism of the product for energy. In this study, 2‐DE, MS/MS, and N‐terminal amino acid sequencing were used to investigate the protein expression profiles of MBA4 grown in a 2‐haloacid (monochloroacetate, MCA) and in the corresponding metabolic product (glycolate). Glycolate was used as a control to eliminate the proteins induced by it. Five proteins were found to be up‐regulated and five proteins were down‐regulated in response to MCA. The differentially expressed proteins were examined, seven of them were identified by MS/MS and two of them were sequenced by Edman degradation. Our results definitely provide an insight for understanding the physiology of B. cepacia MBA4 in response to organohalide contaminated site.
Detection of transient protein–protein interactions by bimolecular fluorescence complementation: The Abl‐SH3 case
Authors: Morell Montse , Espargaró Alba , Avilés Francesc X. , Ventura Salvador 
Published: March 2007

AbstractProtein–protein interactions are essential in most biological processes. Many proteomic approaches have succeeded in the identification of strong and obligatory interactions but the study of weak and transient protein–protein interactions is still a challenge. The aim of the present study was to test the ability of bimolecular fluorescence complementation to detect and discriminate in vivo weak intracellular protein interactions. As a test case, the interaction of the SH3 domain from the c‐Abl tyrosine kinase with both natural and designed targets has been chosen. The reassociation of functional yellow fluorescent protein (YFP) from its fragments requires previous binding between the SH3 domain and its partners; but once this occurs, the complex is trapped, turning transient SH3 interactions into stable, easily detectable ones. The method is very sensitive and can be implemented for proteomic analysis of weak protein interactions using flow cytometry. The fluorescence emission is dependent on the strength of the interaction, in such a way that it can be used, at least qualitatively, to screen for best binding candidates among similar proline‐rich peptides. In addition, it is illustrated how this method can be used to gain structural insights into particular c‐Abl SH3 interactions.
Shotgun immunoproteomics to identify disease‐associated bacterial antigens: Application to human colon cancer
Authors: Tjalsma Harold , Lasonder Edwin , Schöller‐Guinard Marie , Swinkels Dorine W. 
Published: March 2007

AbstractCirculating antibodies reflect a mirror view of invading antigens that are related to infection and cancer. This was recently exemplified by using serum antibodies to capture Streptococcus bovis antigens followed by MS to generate antigen profiles that were diagnostic for colon cancer. These bacterial antigen profiles have a high potential to aid in the immuno‐diagnosis of this disease, as the magnitude of the immune response to bacterial antigens is, in general, superior to the immune response against tumor (self) antigens. In this study, the identity of individual colon cancer‐associated streptococcal antigens was revealed by enrichment of these “diagnostic” antigens by selected patient antibodies followed by high‐accuracy nanoLC‐MS/MS peptide identification. This showed that both the histone‐like protein HlpA and the ribosomal protein Rp L7/L12 are members of the colon cancer‐associated S. bovis immunome. Both antigens also seem to belong to the group of anchorless surface proteins, like 14 additional proteins that were co‐identified in S. bovis cell wall extracts. Among these were the known streptococcal anchorless surface proteins GAPDH and Enolase. Taken together, these data show that shotgun immunoproteomics, combining immunocapture in‐line with LC MS/MS, is a convenient approach for the rapid identification of disease‐associated bacterial antigens.
The structural properties of magainin in water, TFE/water, and aqueous urea solutions: Molecular dynamics simulations
Authors: Mehrnejad Faramarz , Naderi‐Manesh Hossein , Ranjbar Bijan 
Published: March 2007

AbstractHere, the MD simulations and comparative structural analysis of Magainin in water, TFE/water, and 2M, 4M, and BM urea solutions is reported. For MAG‐TFE/water and MAG‐2M urea the largely alpha helical conformation of the peptide is maintained throughout the 9‐ns simulation. While in water, 4M urea, and 8M urea, the helix length decreases and at the same time helix radius increases. This suggests a more destabilized magainin secondary structure. Our simulation data reveals that the stabilizing effect of TFE is induced by preferential accumulation of TFE molecules around the alpha helical peptide. These results indicate that an aqueous urea solution solvates the sutface of polypeptide chain more favorably than pure water. Urea molecules interact more favorably with nonpolar groups of the peptide in comparison with water, and the presence of urea improves the interactions of water molecules with the hydrophilic groups of the peptide. At 8M urea, there are more direct interactions between the urea and solute, and the helix is destabilized. At 2M urea, the interaction of urea molecules and nonpolar residues are weak, therefore, the presence of urea molecules decreases the interactions of water molecules with hydrophilic groups. Urea could not deteriorate the peptide secondary structure with time from an initial helix structure. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Proteochemometric modeling reveals the interaction site for Trp9 modified α‐MSH peptides in melanocortin receptors
Authors: Lapinsh Maris , Prusis Peteris , Petrovska Ramona , Uhlén Staffan , Mutule Ilze , Veiksina Santa , Wikberg Jarl E. S. 
Published: March 2007

AbstractThe interactions of α‐MSH peptides with melanocortin receptors (MCRs) were located by proteochemometric modeling. Nine α‐MSH peptide analogues were constructed by exchanging the Trp9 residue in the α‐MSH core with the natural or artificial amino acids Arg, Asp, Cys, Gly, Leu, Nal, d‐Nal, Pro, or d‐Trp. The nine peptides created, and α‐MSH itself, were evaluated for their interactions with the 4 wild‐type MC1,3–5Rs and 15 multichimeric MCRs, each of the latter being constructed from three sequence segments, each taken from a different wild‐type MC1,3–5R. The segments of the chimeric MCRs were selected according to the principles of statistical molecular design and were arranged so as to divide the receptors into five parts. By this approach, a set of 19 maximally diverse MC receptor proteins was obtained for which the interaction activity with the 10 peptides were measured by radioligand binding thus creating data for 190 ligand–protein pairs, which were subsequently analyzed by use of proteochemometric modeling. In proteochemometrics, the structural or physicochemical properties of both interaction partners, which represent the complementarity of the interacting entities, are used to create multivariate mathematical descriptions. (Here, physicochemical property descriptors of the receptors' and peptides' amino acids were used). A valid, highly predictive (Q2 = 0.74) and easily interpretable model was then obtained. The model was further validated by its ability to correctly predicting the affinity of α‐MSH for new point and cassette‐mutated MC4/MC1Rs, and it was then used to identify the receptor residues that are important for affording the high affinity and selectivity of α‐MSH for the MC1R. It was revealed that these residues are located in several quite distant parts of the receptors' transmembrane cavity and must therefore cause their influence at various stages of the dynamic ligand‐binding process, such as by affecting the conformation of the ligand at the vicinity of the receptor and taking part in the path of the ligand's entry into its binding pocket. Our study can be used as a template how to create high resolution proteochemometric models when there are a limited number of natural proteins and ligands available. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Non‐invasive predictors of survival in cardiac amyloidosis
Authors: Kristen Arnt V. , Perz Jolanta B. , Schonland Stefan O. , Hegenbart Ute , Schnabel Philipp A. , Kristen Joern H. , Goldschmidt Hartmut , Katus Hugo A. , Dengler Thomas J. 
Published: March 2007

AbstractBackground:Patients with cardiac amyloidosis (CA) have increased mortality.Aims:Clinical, electrocardiographic, and echocardiographic parameters were assessed for risk‐stratification of CA.Methods and results:CA was confirmed by endomyocardial biopsy in 59 patients (54.8±1.2 years) with light‐chain (n = 43) or transthyretin amyloidosis (n = 16). Six patients without CA served as controls (NCA). Clinical symptoms, electrocardiographic, and echocardiographic parameters were analyzed for prognostic significance. Of the patients with light‐chain amyloidosis, 14 died and 2 underwent heart transplantation. 1‐/3‐year survival was 68%/63%. Survival depended on left ventricular function (LV‐EF), LV mass, radius/wall thickness, septum thickness, low voltage pattern (LVP), conduction delay, NYHA class, and stem cell transplantation. A multivariate model only contained LV‐EF and LVP; the beneficial effect of stem cell transplantation was cancelled out as this treatment was withheld in patients with highest cardiac risk. Survival was most limited if both risk factors occurred. Cardiac involvement in transthyretin amyloidosis showed better survival (2 deaths, 1‐/3‐year survival 91%/83%). Analysis of prognostic risk factor utility in all amyloid patients (light‐chain and transthyretin) again revealed LVP and LV‐EF, and aetiology of amyloidosis as independent survival parameters.Conclusion:Prognosis of CA is poor, but aetiology of amyloid, LVP, and LV‐EF allows identification of patients at highest risk of death, who may require individual treatment approaches (heart transplantation prior to causative therapy).
Otitis media with effusion: what parents want to know
Authors: Vlastos I M , Hajiioannou J , Houlakis M 
Published: March 2007

AbstractIntroduction:Otitis media with effusion is a common condition of childhood. The development of an information leaflet for parents of children with the condition, and its impact on clinical management, have not previously been examined.Patients and methods:Eighteen doctors and 38 parents assessed the content of an information leaflet on otitis media with effusion, by applying two rounds of the modified Delphi technique. A qualitative assessment of content items was also performed.Results:From the 23-item list used in the first assessment round, four items had a low doctor–parent agreement and seven were excluded. Differences were also noticed in comments on the value of such leaflets, with parents being more positive about the value of leaflet distribution.Conclusion:During the consultation, doctors may not tell parents what they want to know, especially regarding daily care of their child. An information leaflet, developed using the Delphi technique, can help reduce this discrepancy and increase parents' satisfaction.
The Quantum Hall Effect—in Pentacene?
Authors: Levi Barbara Goss 
Published: March 2007

Organic materials have long held promise as possible inexpensive semiconductors in field-effect transistors (FETs) for electronic circuits. No one, however, had dreamed that one might use them to create a two-dimensional gas of electrons or holes and with it to study fundamental electronic behavior. Thus, Bertram Batlogg of Bell Laboratories, Lucent Technologies, stunned an audience at the March Meeting of the American Physical Society in Minneapolis by showing textbook curves of the fractional and integer quantum Hall effects and of an apparent metal-insulator transition—all seen in FETs made with tetracene and pentacene (chains of four and five benzene rings, respectively).
The following news story reports on work that has since been discredited. An independent committee commissioned by Bell Laboratories, Lucent Technologies, found evidence of scientific misconduct in the papers on which it was based (see Physics Today, November 2002, page 15 http://dx.doi.org/10.1063/1.1534995 ). The authors have withdrawn the papers in questions.
Magnaporthe griseaInfection Triggers RNA Variation and Antisense Transcript Expression in Rice
Authors: Gowda Malali , Venu R.-C. , Li Huameng , Jantasuriyarat Chatchawan , Chen Songbiao , Bellizzi Maria , Pampanwar Vishal , Kim HyeRan , Dean Ralph A. , Stahlberg Eric , Wing Rod , Soderlund Cari , Wang Guo-Liang 
Published: March 2007

AbstractRice blast disease, caused by the fungal pathogen Magnaporthe grisea, is an excellent model system to study plant-fungal interactions and host defense responses. In this study, comprehensive analysis of the rice (Oryza sativa) transcriptome after M. grisea infection was conducted using robust-long serial analysis of gene expression. A total of 83,382 distinct 21-bp robust-long serial analysis of gene expression tags were identified from 627,262 individual tags isolated from the resistant (R), susceptible (S), and control (C) libraries. Sequence analysis revealed that the tags in the R and S libraries had a significant reduced matching rate to the rice genomic and expressed sequences in comparison to the C library. The high level of one-nucleotide mismatches of the R and S library tags was due to nucleotide conversions. The A-to-G and U-to-C nucleotide conversions were the most predominant types, which were induced in the M. grisea-infected plants. Reverse transcription-polymerase chain reaction analysis showed that expression of the adenine deaminase and cytidine deaminase genes was highly induced after inoculation. In addition, many antisense transcripts were induced in infected plants and expression of four antisense transcripts was confirmed by strand-specific reverse transcription-polymerase chain reaction. These results demonstrate that there is a series of dynamic and complex transcript modifications and changes in the rice transcriptome at the M. grisea early infection stages.