bluuebunny/crossref_metadata_2025_split huggingface dataset:
New C2‐ and C1‐Symmetric Phosphorus Ligands Based on Carbohydrate Scaffolds and Their Use in the Iridium‐Catalysed Hydrogenation of Ketimines
Authors: Guiu Ester , Aghmiz Mohamed , Díaz Yolanda , Claver Carmen , Meseguer Benjamí , Militzer Christian , Castillón Sergio 
Published: November 2005

AbstractThe C2‐symmetric diphosphinite ligands 10a–d, which have different electron‐donating or electron‐withdrawing groups in the aryl group, and C1‐symmetric phosphinite–phosphite ligands 11a,b, were directly prepared from glucosamine. Various procedures for synthesising the phosphinite function were explored in order to improve the yield of the reaction. Results were best when Ph2PNEt2 was used in the presence of tetrazol as catalyst. These ligands were added to iridium complexes to give catalyst precursors that are active in the hydrogenation of imines 17 and 19. Cationic iridium complexes gave rise to catalytic systems that were more active than the neutral iridium complexes. The use of additives was, in general, detrimental to both the conversion and the enantioselectivity. In the hydrogenation of 17, results were best with ligand 11a (76 % ee), but in the hydrogenation of 19 (70 % ee) they were best with ligand 10b. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Cover Picture: Synthesis and Properties of New Nucleotide Analogues Possessing Squaramide Moieties as New Phosphate Isosters (Eur. J. Org. Chem. 24/2005)
Authors: Seio Kohji , Miyashita Takuhei , Sato Kousuke , Sekine Mitsuo 
Published: November 2005

AbstractThe cover picture shows the electrostatic potential maps of methyl phosphate and N‐methylsquaramide. Various analogs of nucleotides and cyclic nucleotides were synthesized by use of the squaramide moiety as an isoelectronic mimic of the phosphate group. Details are discussed in the article by M. Sekine et al. on p. 5163 ff.
Recent advances in peptide and peptidomimetic stereoisomer separations by capillary electromigration techniques
Authors: Scriba Gerhard K. E. 
Published: November 2005

AbstractAs the stereochemistry of peptides determines their physicochemical properties and biological activities, analytical methods able to discriminate between peptide stereoisomers are important especially with regard to pharmaceutical peptides and peptidomimetics. The present review summarizes recent developments in peptide and peptidomimetic stereoisomer separations by capillary electromigration techniques. The majority of separations were performed by CE while only few reports have been published on the subject of electrochromatography. In addition to systematic studies on the applicability of certain buffer additives and the evaluation of specific experimental conditions, there have been attempts to understand the mechanistic aspects of peptide stereoisomer separations as well as to analyze the structure of peptide–CD complexes.
Progress in capillary electrophoresis of biomarkers and metabolites between 2002 and 2005
Authors: Huck Christian W. , Bakry Rania , Bonn Günther K. 
Published: November 2005

AbstractBiomarker discovery and metabolite research is a fast‐growing and extremely important domain not only for the early detection of certain diseases but also for controlling its progress as well as in pharmaceutical investigations. For the analytical separation and identification, CE plays an indisputable role. Capillary systems enhancing different selectivity are applied and connected to different kind of detection systems. As the choice of buffer and its composition is responsible for a successful separation, special emphasis is put on solvent effects in this review. Altogether the most important capillary electrophoretic techniques applied for biomarker and metabolites analysis published between 2002 and 2005 are summarized and discussed.
Recent applications of affinity interactions in capillary electrophoresis
Authors: Schou Christian , Heegaard Niels H. H. 
Published: November 2005

AbstractSystems biology depends on a comprehensive assignment and characterization of the interactions of proteins and polypeptides (functional proteomics) and of other classes of biomolecules in a given organism. High‐capacity screening methods are in place for ligand capture and interaction screening, but a detailed dynamic characterization of molecular interactions under physiological conditions in efficiently separated mixtures with minimal sample consumption is presently provided only by electrophoretic interaction analysis in capillaries, affinity CE (ACE). This has been realized in different fields of biology and analytical chemistry, and the resulting advances and uses of ACE during the last 2.5 years are covered in this review. Dealing with anything from small divalent metal ions to large supramolecular assemblies, the applications of ACE span from low‐affinity binding of broad specificity being exploited in optimizing selectivity, e.g., in enantiomer analysis to miniaturized affinity technologies, e.g., for fast processing immunoassay. Also, approaches that provide detailed quantitative characterization of analyte–ligand interaction for drug, immunoassay, and aptamer development are increasingly important, but various approaches to ACE are more and more generally applied in biological research. In addition, the present overview emphasizes that distinct challenges regarding sensitivity, parallel processing, information‐rich detection, interfacing with MS, analyte recovery, and preparative capabilities remain. This will be addressed by future technological improvements that will ensure continuing new applications of ACE in the years to come.
Recent applications of microemulsion electrokinetic chromatography
Authors: Huie Carmen W. 
Published: November 2005

AbstractCompared to MEKC, the presence of a water‐immiscible oil phase in the microemulsion droplets of microemulsion EKC (MEEKC) gives rise to some special properties, such as enhanced solubilization capacity and enlarged migration window, which could allow for the improved separation of various hydrophobic and hydrophilic compounds, with reduced sample pretreatment steps, unique selectivities and/or higher efficiencies. Typically, stable and optically clear oil‐in‐water microemulsions containing a surfactant (SDS), oil (octane or heptane), and cosurfactant (1‐butanol) in phosphate buffer are employed as separation media in conventional MEEKC. However, in recent years, the applicability of reverse MEEKC (water‐in‐oil microemulsions) has also been demonstrated, such as for the enhanced separation of highly hydrophobic substances. Also, during the past few years, the development and application of MEEKC for the separation of chiral molecules has been expanded, based on the use of enantioselective microemulsions that contained a chiral surfactant or chiral alcohol. On the other hand, the application of MEEKC for the characterization of the lipophilicity of chemical substances remains an active and important area of research, such as the use of multiplex MEEKC for the high‐throughput determination of partition coefficients (log P values) of pharmaceutical compounds. In this review, recent applications of MEEKC (covering the period from 2003 to 2005) are reported. Emphases are placed on the discussion of MEEKC in the separation of chiral molecules and highly hydrophobic substances, as well as in the determination of partition coefficients, followed by a survey of recent applications of MEEKC in the analysis of pharmaceuticals, cosmetics and health‐care products, biological and environmental compounds, plant materials, and foods.
Recent advances in the application of capillary electrophoresis with mass spectrometric detection
Authors: Klampfl Christian W. 
Published: November 2005

AbstractThis review gives an overview of applications of CE coupled to MS detection published in the literature of the last three years. The works discussed in this paper comprise a wide range of different fields of application. These include important sections such as the analysis of biomolecules, the analysis of pharmaceuticals and their metabolites in different matrices, environmental analysis, and also investigations on the composition of technical products.
Recent applications in capillary electrochromatography
Authors: Eeltink Sebastiaan , Kok Wim Th. 
Published: November 2005

AbstractIn this review research papers on the application of CEC are summarized that have been published between May 2003 and May 2005. First, a short overview is given of trends and developments in CEC that may increase the applicability of the separation technique. Next, application‐oriented research using CEC is described in biochemical studies, including proteomics and genomics, in the analysis of food and natural products, and in pharmaceutical, industrial, and environmental analysis.
Pharmacokinetic applications of capillary electrophoresis: A review on recent progress
Authors: Sung Wang‐Chou , Chen Shu‐Hui 
Published: November 2005

AbstractThis article covers recent publications from 2003 to 2005 on the subject of pharmacokinetic applications of CE. Many analytical methods were validated and more importantly, they were shown to have sufficient sensitivities to access pharmacokinetic data on different models. Because of unique advantages, such as simplified sample preparation methods, small sample amount required, high separation power, and speedy analysis, CE‐based assays were found to gain popularity not only as a second method but also as a major method for many pharmacokinetic studies.
The role of astragaloside in regeneration of the peripheral nerve system
Authors: Cheng Chun‐Yuan , Yao Chun‐Hsu , Liu Bai‐Shuan , Liu Chien‐Ju , Chen Guan‐Wei , Chen Yueh‐Sheng 
Published: November 2005

AbstractThe aim of this study was to evaluate peripheral nerve regeneration across a 15‐mm gap in the sciatic nerve of the rat, using a silicone rubber nerve guide filled with different concentrations of astragaloside (0, 50, 100, and 200 μM). Collagen was also filled in the chambers to prevent the astragaloside from leakage. At the end of 8 weeks, animals from the group treated with astragaloside, especially at the concentration of 50 μM, had a higher rate of successful regeneration across the wide gap, a significantly larger number of myelinated axons, and a greater evoked action potential than the control group. However, the high‐dose astragaloside (200 μM) completely reversed this positive effect of growth‐promoting capability and inhibited nerve regeneration. Thus, astragaloside plays a dual role in anastomosis, being salutary in aiding the growth of axons in peripheral nerve but also detrimental, terminating the nerve regenerative processes if improperly applied. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Investigation into the erosion mechanism of salicylate‐based poly(anhydride‐esters)
Authors: Whitaker‐Brothers Kenya , Uhrich Kathryn 
Published: November 2005

AbstractSalicylate‐based poly(anhydride‐esters), collectively referred to as PolyAspirin™, hydrolytically degrade into salicylic acid, a nonsteroidal anti‐inflammatory drug (NSAID). The variations of the poly(anhydride‐ester) investigated in this article are linked by adipic acid, suberic acid, or sebacic acid. To elucidate the erosion mechanism of these polymers, water uptake, mass loss, contact angle, and changes in device thickness were monitored as a function of in vitro degradation time. The polymers examined here appeared to primarily undergo surface erosion. The adipate homopolymer absorbed the most water and therefore swelled more than the other versions of the poly(anhydride‐ester). Additionally, the adipate homopolymer eroded most quickly. Increasing the length of the linker moiety decreased the driving force for hydrolysis, which prolonged the lifetime of the polymer sample. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Biocompatibility and degradation of aliphatic segmented poly(ester amide)s: In vitro and in vivo evaluation
Authors: Lips Priscilla A. M. , van Luyn Marja J. A. , Chiellini Federica , Brouwer Linda A. , Velthoen Ingrid W. , Dijkstra Piet J. , Feijen Jan 
Published: November 2005

AbstractAliphatic segmented poly(ester amide)s, comprising a crystallizable amide phase and a flexible amorphous ester phase, were investigated for potential use in biomedical applications. By varying the amide content and the type of crystallizable amide segments, the polymer's thermal and mechanical properties can readily be tuned. Polymers with 25 and 50 mol % of amide content are noncytotoxic and sustain growth of fibroblasts onto polymer films. The in vitro degradation of these polymers was followed in PBS (pH 7.4) at 37°C up to 7 months. The poly(ester amide)s showed the characteristics of bulk degradation with a gradual decrease in molecular weight and almost no mass loss. The in vivo degradation of these polymers, followed by subcutaneous implantation in rats up to 6 weeks, was slow and similar to the in vitro degradation. The tissue response upon implantation was followed over 6 weeks. A mild foreign‐body reaction, characterized by the presence of macrophages, and sporadically a lymphocyte, were observed in the first week of implantation. After 6 weeks the implant site is characterized by fibrous encapsulation with no signs of inflammation. The poly(ester amide)s tested are biocompatible, but their in vitro as well as in vivo degradation is very slow. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Chitosan monomer promotes tissue regeneration on dental pulp wounds
Authors: Matsunaga Tsunenori , Yanagiguchi Kajiro , Yamada Shizuka , Ohara Naoko , Ikeda Takeshi , Hayashi Yoshihiko 
Published: November 2005

AbstractThe present study was undertaken to evaluate the applicability of chitosan monomer (D‐glucosamine hydrochloride) as a pulp capping medicament. Bothin vitroandin vivoexperiments were carried out to study the cell metabolism and wound healing mechanisms following the application of chitomonosaccharide. After 3 days of osteoblast culture, alkaline phosphatase (ALP) activity significantly increased in the chitosan group. Reverse transcription polymerase chain reaction analysis revealed that chitosan induced an increase in the expression of ALP mRNA after 3 days and bone morphogenetic protein‐2 mRNA after 7 days of osteoblast incubation. Inflammatory cytokine, interleukin (IL)‐8, synthesis in fibroblasts was strongly suppressed in the medium supplemented with chitosan monomer. Histopathological effects were evaluated in rat experiments. After 1 day, inflammatory cell infiltrations were observed to be weak when compared with the application of chitosan polymer. After 3 days, a remarkable proliferation of fibroblasts was seen near the applied chitosan monomer. The inflammatory cell infiltration had almost completely disappeared. After 5 days, the fibroblastic proliferation progressed, and some odontoblastic cells appeared at the periphery of the proliferated fibroblasts. These findings indicate that the present study is the first report that chitosan monomer acts as a biocompatibly stable medicament even at the initial stage of wound healing in comparison with the application of chitosan polymer. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Rheological and cohesive properties of hyaluronic acid
Authors: Falcone Samuel J. , Palmeri David M. , Berg Richard A. 
Published: November 2005

AbstractHyaluronic acid (HA) is a naturally occurring polysaccharide with unique biomedical applications. We have studied the cohesive and rheological properties of HA of three molecular weights (0.35 × 106 –1.80 × 106 Da) and found that the cohesive nature of HA was highly dependent on molecular weight and solution concentration. To a first approximation, the cohesive nature of HA in solution correlates with concentration, independent of molecular weight. Several rheological parameters correlated with molecular weight: zero shear viscosity, complex viscosity, and the complex viscosity at the crossover point. The cohesive properties of the HA solutions, measured by dynamic aspiration (Poyer et al, J Cataract Refract Surg 1998;24:1130–1135), were found to decrease as the zero shear viscosity increases. The cohesive properties of HA polymer in solution were found to correlate with the high frequency complex viscosity and high frequency loss modulus independent of molecular weight. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Gene expression in the cell cycle of human T lymphocytes: I. Predicted gene and protein networks
Authors: Sivozhelezov V. , Giacomelli L. , Tripathi S. , Nicolini C. 
Published: November 2005

AbstractThe key genes involved in the cell cycle of human T lymphocytes were identified by iterative searches of gene‐related databases, as derived also from DNA microarray experimentation, revealing and predicting interactions between those genes, assigning scores to each of the genes according to numbers of interaction for each gene weighted by significance of each interaction, and finally applying several types of clustering algorithms to genes basing on the assigned scores. All clustering algorithms applied, both hierarchical and K‐means, invariably selected the same six “leader” genes involved in controlling the cell cycle of human T lymphocytes. Relations of the six genes to experimental data describing switching between stages of cell cycle of human T lymphocytes are discussed. J. Cell. Biochem. 97: 1137–1150, 2006. © 2005 Wiley‐Liss, Inc.
Gene expression in the cell cycle of human T‐lymphocytes: II. Experimental determination by DNASER technology
Authors: Nicolini Claudio , Spera Rosanna , Stura Enrico , Fiordoro Stefano , Giacomelli Luca 
Published: November 2005

AbstractHuman lymphocytes gene expression before and after PHA stimulation is monitored by DNASER technology, a novel bioinstrumentation entirely constructed in our laboratories as previously reported. The validity of the DNASER measurements is confirmed by standard fluorescence microscopy equipped with CCD. The human lymphocytes gene expression here experimentally probed using commercially available DNA microarrays such as Human Starter, appears compatible both with independent bioinformatic prediction and with existing experimental data, pointing to MYC as the key gene in the G0–G1 transition induced by PHA in resting lymphocytes. It does not escape our notice that in cell biology and cancer research DNASER technology based on microarray constructed with few leader genes identified from bioinformatics represents a meaningful cost‐effective route alternative to massive frequently misleading molecular genomics. J. Cell. Biochem. 97: 1151–1159, 2006. © 2005 Wiley‐Liss, Inc.
Regulation of DNA repair gene expression in human cancer cell lines
Authors: McGurk Claire J. , Cummings Michele , Köberle Beate , Hartley John A. , Oliver R. Timothy , Masters John R. 
Published: November 2005

AbstractAlthough most advanced cancers are incurable, the majority of testicular germ cell tumors can be cured using cisplatin‐based combination chemotherapy. The nucleotide excision repair (NER) pathway removes most DNA adducts produced by cisplatin, and the low levels of NER in testis tumor cells may explain why these cancers are curable. Three NER proteins: ERCC1, XPF, and XPA, are present at low levels in testis tumor cell lines, and addition of these proteins to protein extracts of testis tumor cells increases their in vitro DNA repair capacity to normal levels. The aim of this study was to identify the mechanism responsible for the low levels of these DNA repair proteins. The levels of the mRNA transcripts for ERCC1, XPF, and XPA were measured in a panel of 14 different human cancer cell lines, using real‐time PCR. Three ERCC1 splice variants were identified and quantitated. Three alternative transcription start points (TSPs) were identified for ERCC1 but none were testis‐specific. The significantly lower levels of ERCC1, XPF, and XPA protein in testis tumor cell lines cannot be explained solely by differences in transcriptional efficiency or mRNA stability. For ERCC1, post‐transcriptional control by alternative splicing does not account for the testis‐specific low levels of protein expression. Pulse‐chase experiments showed that the half‐life of ERCC1 protein in a testis tumor cell line was not significantly different to that in a prostate cancer cell line. Taken together, these results suggest that constitutive levels of these DNA repair proteins are controlled at the level of translation. J. Cell. Biochem. 97: 1121–1136, 2006. © 2005 Wiley‐Liss, Inc.
Osteogenic differentiation of human mesenchymal stem cells is regulated by bone morphogenetic protein‐6
Authors: Friedman Michael S. , Long Michael W. , Hankenson Kurt D. 
Published: November 2005

AbstractBone marrow‐derived mesenchymal stem cells (MSC) are multipotent, self‐renewing, mesodermal‐origin stem cells that are sequestered in the endosteal compartment. MSC are maintained in a relative state of quiescence in vivo but in response to a variety of physiological and pathological stimuli, proliferate and differentiate into osteoblasts, chondrocytes, adipocytes, or hematopoiesis‐supporting stromal cells. Little is understood regarding the cellular or molecular events underlying MSC fate decisions. We report that human MSC (hMSC) cultured in defined, serum‐free conditions respond to a narrow spectrum of growth factors with osteogenic commitment, differentiation, and hydroxyapatite deposition. Of the osteogenic factors we examined, only treatment with bone morphogenetic protein (BMP) results in osteoinduction under defined serum‐free conditions. Among BMP‐2, 4, 6, and 7, BMP‐6 is the most consistent and potent regulator of osteoblast differentiation and, of these BMPs, only BMP‐6 gene expression is detected prior to hMSC osteoblast differentiation. Addition of exogenous BMP‐6 to hMSC induces the expression or upregulation of a repertoire of osteoblast‐related genes including type I collagen, osteocalcin, bone sialoprotein, and their regulatory transcription factors Cbfa1/Runx2, and Osterix. This translates into increased production of osteogenic extracellular matrix (ECM) with subsequent hydroxyapatite deposition. J. Cell. Biochem. 98: 538–554, 2006. © 2005 Wiley‐Liss, Inc.
Intracellular proteolytic activity of cathepsin B is associated with capillary‐like tube formation by endothelial cells in vitro
Authors: Premzl Aleš , Turk Vito , Kos Janko 
Published: November 2005

AbstractThe lysosomal cysteine protease cathepsin B is implicated in degradation of extracellular matrix (ECM), a crucial step in a variety of physiological and pathological processes, including tumor dissemination and angiogenesis. In this study, we analyzed the contribution of extracellular and intracellular cathepsin B activity on the formation of capillary‐like tubular structures by human umbilical vein endothelial cells (HUVECs) grown on Matrigel matrix, using general and specific cysteine protease inhibitors. We demonstrated, by confocal assay using quenched fluorescent protein substrate DQ‐collagen IV, that endothelial cells degrade ECM both intracellularly and pericellularly. Intracellular cathepsin B activity detected by degradation of Z‐Arg‐Arg cresyl violet substrate was co‐localized with the products of DQ‐collagen IV degradation in the perinuclear region and in the capillary‐like tubular structures. Treatment of cells with membrane‐permeable CA‐074 Me effectively abolished intracellular cathepsin B activity, and resulted in reduced tube length (32.3 ± 9.4% at 10 µM), total tubule area (49.6 ± 12.4% at 10 µM), and the number of branch points of tubules (47.5 ± 7.7% at 10 µM) in a dose‐dependent manner. In contrast, CA‐074 (0.1–10 µM), a membrane‐impermeable cathepsin B specific inhibitor, general cysteine protease inhibitors chicken cystatin (5 µM) and E‐64 (10 µM), and the metalloprotease inhibitor Minocycline (10 µM) showed no significant inhibitory effect in our angiogenesis model. These results show that, besides multiple regulatory molecules, intracellular cathepsin B also contributes to the neovascularization process and should be considered as a potential therapeutic target. J. Cell. Biochem. 97: 1230–1240, 2006. © 2005 Wiley‐Liss, Inc.