bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using peptides to study the interaction between the p53 tetramerization domain and HIV‐1 tat
Authors: Gabizon Ronen , Mor Michal , Rosenberg Masha M. , Britan Lena , Hayouka Zvi , Kotler Moshe , Shalev Deborah E. , Friedler Assaf 
Published: January 2008

AbstractPeptides are valuable tools for studying protein–protein interactions, especially in cases of isolated protein domains and natively unfolded proteins. Here, we used peptides to quantitatively characterize the interaction between the natively unfolded HIV‐1 Tat protein and the tetramerization domain of the cellular tumor suppressor protein p53. We used peptide mapping, fluorescence anisotropy, and NMR spectroscopy to perform a detailed structural and biophysical characterization of the interaction between the two proteins and elucidate its molecular mechanism, which have so far been studied using cell‐based methods. We show that the p53 tetramerization domain, p53(326–355), binds directly to residues 1–35 and 47–57 in Tat. We have characterized the interaction between p53(326–355) and Tat(47–57) in detail. The p53 residues that are mainly involved in binding to Tat(47–57) are E343 and E349, which bind to the positively charged arginine‐rich motif of Tat by a partly electrostatic mechanism. All oligomerization states of p53(326–355) bind Tat(47–57) without inhibiting p53 tetramerization, since the residues in p53(326–355) that bind Tat(47–57) face away from the tetramerization interface. We conclude that p53 is able to bind Tat as a transcriptionally active tetramer. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 105–116, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Reviewing the vascular supply of the anterior abdominal wall: Redefining anatomy for increasingly refined surgery
Authors: Rozen W.M. , Ashton M.W. , Taylor G.I. 
Published: January 2008

AbstractThe abdominal wall integument is becoming the standard donor tissue for postmastectomy breast reconstruction, with its vascular supply of key importance to the reconstructive surgeon. Refinements in tissue transfer, from pedicled to free flaps and musculocutaneous to perforator flaps, have required increasing understanding of finer levels of this vascular anatomy. The widespread utilization of the deep inferior epigastric artery (DIEA) perforator flap, particularly for breast reconstruction, has rekindled clinical interest in further levels of anatomical detail, in particular the location and course of the musculocutaneous perforators of the DIEA. Advances in operative techniques, and anatomical and imaging technologies, have facilitated an increase in this understanding. The current review comprises an appraisal of both the anatomical and clinical literature, with a view to highlighting the key anatomical features of the abdominal wall vasculature as related to reconstructive flaps. Clin. Anat. 21:89–98, 2008. © 2008 Wiley‐Liss, Inc.
Probing Defect Sites on TiO2 with [Re3(CO)12H3]: Spectroscopic Characterization of the Surface Species
Authors: Suriye Kongkiat , Lobo‐Lapidus Rodrigo J. , Yeagle Gregory J. , Praserthdam Piyasan , Britt R. David , Gates Bruce C. 
Published: January 2008

AbstractSamples of the anatase phase of titania were treated under vacuum to create Ti3+ surface‐defect sites and surface O− and O2− species (indicated by electron paramagnetic resonance (EPR) spectra), accompanied by the disappearance of bridging surface OH groups and the formation of terminal Ti3+OH groups (indicated by IR spectra). EPR spectra showed that the probe molecule [Re3(CO)12H3] reacted preferentially with the Ti3+ sites, forming Ti4+ sites with OH groups as the [Re3(CO)12H3] was adsorbed. Extended X‐ray absorption fine structure (EXAFS) spectra showed that these clusters were deprotonated upon adsorption, with the triangular metal frame remaining intact; EPR spectra demonstrated the simultaneous removal of surface O− and O2− species. The data determined by the three complementary techniques form the basis of a schematic representation of the surface chemistry. According to this picture, during evacuation at 773 K, defect sites are formed on hydroxylated titania as a bridging OH group is removed, forming two neighboring Ti3+ sites, or, when a Ti4+O bond is cleaved, forming a Ti3+ site and an O− species, with the Ti4+OH group being converted into a Ti3+OH group. When the probe molecule [Re3(CO)12H3] is adsorbed on a titania surface with Ti3+ defect sites, it reacts preferentially with these sites, becoming deprotonated, removing most of the oxygen radicals, and healing the defect sites.
Molecular characterization of axonemal proteins and signaling molecules responsible for chemoattractant‐induced sperm activation in Ciona intestinalis
Authors: Hozumi Akiko , Padma Potturi , Toda Tosifusa , Ide Hiroyuki , Inaba Kazuo 
Published: January 2008

AbstractSpermatozoa undergo dramatic physiological changes at fertilization. In the ascidian Ciona intestinalis, an egg‐derived substance named SAAF induces both sperm activation and chemotaxis to the egg. To elucidate the molecular mechanism underlying these phenomena, whole sperm proteins before and after SAAF‐treatment were analyzed by two‐dimensional gel electrophoresis. By comparison of spot patterns before and after activation, we found twelve proteins that changed the isoelectric points. Seven proteins were shown to be axonemal proteins and others were suggested to be non‐axonemal components. Analysis of these proteins by MS‐based proteomic system revealed that components of several substructures of the axonemes underwent the changes in isoelectric point at sperm activation, including WD‐repeat intermediate chains of outer and inner arm dyneins and a radial spoke protein LRR37, as well as novel axonemal proteins with armadillo repeats or SMC domain. Molecules for cell signaling such as 14‐3‐3 proteins, Skp1 and VCP/p97 also showed isoelectric changes at sperm activation. These results show a comprehensive feature for signaling mechanism of the activation of spermatozoa at fertilization and also shed new lights on the regulation of ciliary and flagellar movements. Cell Motil. Cytoskeleton 2008. © 2008 Wiley‐Liss, Inc.
Retinal cone topography of artiodactyl mammals: Influence of body height and habitat
Authors: Schiviz Alexandra Nathalie , Ruf Thomas , Kuebber‐Heiss Anna , Schubert Christian , Ahnelt Peter Kurt 
Published: January 2008

AbstractThis study addresses the correlation of retinal topography with factors such as the visual environment, life style, and behavior for a major mammalian group, the artiodactyls. To provide a broader basis for semiquantitative comparison, short‐wavelength‐sensitive (S)‐ and middle‐to‐long‐wavelength‐sensitive (M)‐opsin cone receptor populations from 25 species from five artiodactyl families and of the African elephant were labeled and sampled. The resulting topographic maps were analyzed with respect to the position and extension of high‐density regions. For better parameter differentiation, systematic relationships were statistically normalized. In all species examined, two classes of cones have been detected. In most species, the S‐cone maxima were located in the temporodorsal retina, but there are exceptions such as the roe deer with accumulation in the ventral retina. For M‐cones, as a consequence of their role in terrain/food assessment and predator detection, the standard topography is L‐shaped: a horizontal visual streak including a temporal area centralis is extended by a temporal rim. Its extension is correlated with the animal's body height (P = 0.0017): small species (pudu, mouse deer) tend to have a visual streak only, whereas the giraffe shows a complete dorsal arch of elevated densities. Furthermore, a size‐independent habitat correlation was revealed for a similar M‐cone pattern (P < 0.0001): mountainous species show a striking specialization around the dorsal retina, pointing to the importance of the inferior visual field in precipitous terrain. J. Comp. Neurol. 507:1336–1350, 2008. © 2008 Wiley‐Liss, Inc.
Singlet and Triplet Excited States and Intersystem Crossing in Free‐Base Porphyrin: TDDFT and DFT/MRCI Study
Authors: Perun Serhiy , Tatchen Jörg , Marian Christel M. 
Published: January 2008

AbstractExtensive time‐dependent DFT (TDDFT) and DFT/multireference configuration interaction (MRCI) calculations are performed on the singlet and triplet excited states of free‐base porphyrin, with emphasis on intersystem crossing processes. The equilibrium geometries, as well as the vertical and adiabatic excitation energies of the lowest singlet and triplet excited states are determined. Single and double proton‐transfer reactions in the first excited singlet state are explored. Harmonic vibrational frequencies are calculated at the equilibrium geometries of the ground state and of the lowest singlet and triplet excited states. Furthermore, spin–orbit coupling matrix elements of the lowest singlet and triplet states and their numerical derivatives with respect to nuclear displacements are computed. It is shown that opening of an unprotonated pyrrole ring as well as excited‐state single and double proton transfer inside the porphyrin cavity lead to crossings of the potential energy curves of the lowest singlet and triplet excited states. It is also found that displacements along out‐of‐plane normal modes of the first excited singlet state cause a significant increase of the <T2|Hso|S1>, <T1|Hso|S1>, and <T1|Hso|S0> spin–orbit coupling matrix elements. These phenomena lead to efficient radiationless deactivation of the lowest excited states of free‐base porphyrin via intercombination conversion. In particular, the S1→T1 population transfer is found to proceed at a rate of ≈107 s−1 in the isolated molecule.
A flow cytometer for the measurement of Raman spectra
Authors: Watson Dakota A. , Brown Leif O. , Gaskill Daniel F. , Naivar Mark , Graves Steven W. , Doorn Stephen K. , Nolan John P. 
Published: January 2008

AbstractMultiparameter measurements in flow cytometry are limited by the broad emission spectra of fluorescent labels. By contrast, Raman spectra are notable for their narrow spectral features. To increase the multiparameter analysis capabilities of flow cytometry, we investigated the possibility of measuring Raman signals in a flow cytometry‐based system. We constructed a Raman Spectral Flow Cytometer, substituting a spectrograph and CCD detector for the traditional mirrors, optical filters, and photomultiplier tubes. Excitation at 633 nm was provided by a HeNe laser, and forward‐angle light scatter is used to trigger acquisition of complete spectra from individual particles. Microspheres were labeled with nanoparticle surface enhanced Raman scattering (SERS) tags and measured using the RSFC. Fluorescence and Raman spectra from labeled microspheres were acquired using the Raman Spectral Flow Cytometer. SERS spectral intensities were dependent on integration time, laser power, and detector pixel binning. Spectra from particles labeled with one each of four different SERS tags could be distinguished by either a virtual bandpass approach using commercial flow cytometry data analysis software or by principal component analysis. Raman flow cytometry opens up new possibilities for highly multiparameter and multiplexed measurements of cells and other particles using a simple optical design and a single detector and light source. © 2008 International Society for Analytical Cytology
Cellular volume and marker expression in human peripheral blood apheresis stem cells
Authors: Sharma Siddharth , Cabana Raquel , Shariatmadar Sherry , Krishan Awtar 
Published: January 2008

AbstractCoulter volume is far more accurate measure of cell volume than forward angle light scatter. In this report, we have used Coulter volume to determine the mean cell volume and diameter of normal human peripheral blood cells and hematopoietic progenitor cells obtained by apheresis (HPC‐A) from patients with hematological malignancies. Fresh peripheral blood samples (treated with Beckman Coulter IMMUNOPrep erythrocyte lysis solution), HPC‐A samples (treated with BD Biosciences FACSLysing solution), or processed by Ficoll Hypaque sedimentation method were stained with CD45‐FITC and PE‐labeled CD34, CD90, CD117, and CD133 antibodies and analyzed for electronic volume and two color fluorescence. The mean electronic volume and diameter of mononuclear cells from fresh peripheral blood samples prepared with IMMUNOPrep were lymphocytes (191 μm3, 7.16 μm), monocytes (370 μm3, 9.91 μm), and granulocytes (328 μm3, 8.56 μm). In mononuclear cells of HPC‐A samples prepared by Histopaque‐1077 sedimentation, the lymphocytes had volume and diameter of 311 μm3, 8.4 μm, monocytes were 486 μm3, 9.76 μm, and granulocytes were 515 μm3, 9.95 μm. In contrast, HPC‐A samples prepared after lysis with FACSLysing solution had mean electronic volume and diameter of lymphocytes (414 μm3, 9.25 μm), monocytes (797 μm3, 11.5 μm), and granulocytes (670 μm3, 10.85 μm). Cell volume of mononuclear cells in the HPC‐A samples prepared by Histopaque‐1077 sedimentation method was correlated with the expression of stem cell markers CD34, CD90, CD117, and CD133. CD90 positive cells had the smallest mean electronic volume of 299.93 μm3 when compared with cells with positive expression of CD133 (322 μm3), CD117 (349 μm3), CD34 (407 μm3), and CD45 (453 μm3). Correlation of cell volume with stem cell marker expression may allow for the identification of small stem cells, which may not express the conventional markers used for the identification of stem cells in HPC‐A samples. © 2008 International Society for Analytical Cytology
Recent Approaches in the Synthesis of Conformationally Restricted Nucleoside Analogues
Authors: Mathé Christophe , Périgaud Christian 
Published: January 2008

AbstractThis review describes some approaches in the synthesis of conformationally restricted nucleoside analogues. The focus is on the preparation of nucleosides as monomers modified only on the pentofurano sugar moiety, with an additional linkage capable of modulating the dynamic conformational equilibrium of natural nucleosides. The results of the different structural modifications in terms of pseudorotational analysis, as well as the potential use of such conformationally restricted nucleoside analogues, are briefly presented.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Microscale solution IEF combined with 2‐D DIGE substantially enhances analysis depth of complex proteomes such as mammalian cell and tissue extracts
Authors: Han Mee‐Jung , Herlyn Meenhard , Fisher Aron B. , Speicher David W. 
Published: January 2008

AbstractCurrent gel‐based protein profiling methods such as 2‐DE and fluorescent 2‐D difference in gel electrophoresis (DIGE) evaluate small portions of complex proteomes. Hence, sample prefractionation is essential for more comprehensive proteome coverage and detection of low‐abundant proteins. In this study, we describe the combination of DIGE labeling with microscale solution IEF (MicroSol‐IEF) fractionation and subsequent analysis on slightly overlapping narrow pH range 2‐D gels. By fluorescently tagging and mixing samples and controls prior to prefractionation, complications resulting from minor run‐to‐run variations during MicroSol‐IEF separations of multiple samples are avoided. This greatly improves the reliability of quantitative comparisons. To illustrate its utility, this 3‐D DIGE strategy was applied to analysis of human melanoma cells and mouse lung tissue extracts. Approximately 1000 reproducible spots can be obtained from narrow range 2‐D gels of individual MicroSol‐IEF fractions, and approximately 6000 spots can be obtained from entire proteomes. Quantitative changes in closely related samples could be more reliably detected and the method has a greatly increased capacity to distinguish between closely related protein isoforms. Thus the 3‐D DIGE strategy produces a powerful method for more comprehensive and more reliable quantitative comparisons of protein profiles of very complex proteomes.
Determination of linear response in the detection of mixtures of aroma compounds by atmospheric pressure ionization–mass spectrometry (API–MS)
Authors: Buffo Roberto A. , Reineccius Gary A. 
Published: January 2008

AbstractThe linearity of atmospheric pressure ionization–mass spectrometry (API–MS) response in mixtures of aroma compounds was determined for a ‘homogeneous’ system (four esters) and a ‘heterogeneous’ system (five compounds of different chemical functionality). All combinations analysed within each system followed a saturation pattern as concentration increased. Total linear responses were determined by the linear behaviour of individual compounds. Ionization patterns within each mixture were explained by proton affinity data (i.e. the species' ability to accept protons), molecular reaction rates (defined by molecular weight), and product ion distribution (according to fragmentation of the corresponding parent ion). Copyright © 2007 John Wiley & Sons, Ltd.
Distributional consequences of the transition from age‐based to income‐based prescription drug coverage in British Columbia, Canada
Authors: Hanley Gillian E. , Morgan Steve , Hurley Jeremiah , van Doorslaer Eddy 
Published: January 2008

AbstractIn May, 2003, British Columbia transitioned from an age‐based public drug program, with public subsidy primarily based on age, to an age‐irrelevant income‐based drug program, in which public subsidy is based primarily on household income. As one of the specific aims of the policy change was to improve fairness by increasing the extent to which payment for drugs is based on ability to pay, we measure the progressivity of pharmaceutical financing before and after the policy change in BC using Kakwani indices. Our results suggest that pharmaceutical financing became less regressive after the policy change. However, this decrease in regressivity arose primarily because high‐income seniors were making greater direct contributions to pharmaceutical financing and not because low‐income households were making smaller direct contributions. Our results also suggest that if the public financing of pharmaceuticals were maintained or increased, a change from age‐based to income‐based eligibility can unambiguously improve equity in finance. As populations in developed countries age, governments will increasingly consider reforms to publicly financed health‐care programs with age‐based eligibility. In assessing policy options, financial equity is likely to be a key consideration. These results suggest that income‐based pharmacare can improve financial equity especially when implemented with a commitment to maintain or increase public funding for prescription drugs. Copyright © 2008 John Wiley & Sons, Ltd.
Potential effects of a low‐molecular‐weight fucoidan extracted from brown algae on bone biomaterial osteoconductive properties
Authors: Changotade S. Igondjo Tchen , Korb G. , Bassil J. , Barroukh B. , Willig C. , Colliec‐Jouault S. , Durand P. , Godeau G. , Senni K. 
Published: January 2008

AbstractIn this work, we first tested the influence of low‐molecular‐weight (LMW) fucoidan extracted from pheophicae cell wall on bidimensional cultured normal human osteoblasts' behaviors. Second, by impregnation procedure with LMW fucoidan of bone biomaterial (Lubboc®), we explored in this bone extracellular matrix context its capabilities to support human osteoblastic behavior in 3D culture. In bidimensionnal cultures, we evidenced that LMW fucoidan promotes human osteoblast proliferation and collagen type I expression and favors precocious alkaline phosphatase activity. Furthermore, with LMW fucoidan, von Kossa's staining was positive at 30 days and positive only at 45 days in the absence of LMW fucoidan. In our three‐dimensional culture models with the biomaterial pretreated with LMW fucoidan, osteoblasts promptly overgrew the pretreated biomaterial. We also evidenced that osteoblasts increased proliferation with pretreated biomaterial when compared with untreated biomaterial. Osteoblasts secreted osteocalcin and expressed BMP2 receptor on control material as well as with LMW fucoidan impregnated biomaterial. In conclusion, in our experimental conditions, LMW fucoidan stimulated expression of osteoblastic markers differentiation such as alkaline phosphatase activity, collagen type I expression, and mineral deposition; furthermore, cell proliferation was favored. These findings suggest that fucoidan could be clinically useful for bone regeneration and bone substitute design. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Decreased DMT1 and increased ferroportin 1 expression is the mechanisms of reduced iron retention in macrophages by erythropoietin in rats
Authors: Kong Wei‐Na , Zhao Shu‐E , Duan Xiang‐Lin , Yang Zhe , Qian Zhong‐Ming , Chang Yan‐Zhong 
Published: January 2008

AbstractRecycled iron from reticuloendothelial macrophages to erythroid precursors is important to maintain the iron homeostasis. However, the molecular mechanisms underlying iron homeostasis in macrophages are poorly understood. In this study, male Sprague–Dawley rats were treated with recombinant human erythropoietin (rHuEpo, 500 IU/day, s.c.) for 3 days. At the fifth day, peritoneal exudate macrophages were harvested, and then 55Fe uptake and release were measured by liquid scintillation counting method. The expression of divalent metal transporter 1 (DMT1) and ferroportin 1 (FPN1) in peritoneal exudate macrophages was detected by RT‐PCR and Western blot. In order to exclude the direct effect of rHuEpo on macrophages, the parallel experiments were performed with incubation normal peritoneal exudate macrophages with rHuEpo (2 IU/ml). Our results showed rHuEpo injection reduced the peritoneal exudate macrophages iron retention. The uptake of Fe(II) was decreased via the suppression of DMT1 (+IRE) expression and the release of Fe(II) was increased with increasing the expression of FPN1 in macrophages. Moreover, the expression of HAMP mRNA was four times lower in rHuEpo‐treated liver of rats than control group (CG). HAMP mRNA expression was increased; the synthesis of DMT1 had no significant change, whereas the FPN1 was decreased in normal peritoneal exudate macrophages after treatment with rHuEpo in vitro. We conclude that hepcidin may play a major, causative role in the change of FPN1 synthesis and that decreased the iron retention in macrophages of rHuEpo‐treated rats. J. Cell. Biochem. 104: 629–641, 2008. © 2008 Wiley‐Liss, Inc.