bluuebunny/crossref_metadata_2025_split huggingface dataset:
First Observation by Fluorescence Polarization of Complexation between mRNA and the Natural Polysaccharide Schizophyllan
Authors: Karinaga Ryouji , Mizu Masami , Koumoto Kazuya , Anada Takahisa , Shinkai Seiji , Kimura Taro , Sakurai Kazuo 
Published: April 2004

AbstractSchizophyllan is a natural β‐(1→3)‐D‐glucan that exists as a triple helix in H2O and as a single chain in dimethylsulfoxide (DMSO) or basic solution (pH >13). As we have already reported, when a homo‐polynucleotide (e.g., poly(dA), poly(A), or poly(C)) is added to a schizophyllan/DMSO solution, and, subsequently, DMSO is exchanged for H2O, the single chain of schizophyllan forms a complex with the polynucleotide. Since eukaryotic mRNAs have poly(A) tails, we hypothesized that schizophyllan can bind to mRNA by interacting with this tail. However, we have not yet observed complexation between schizophyllan and mRNA after exchanging DMSO for H2O. In this report, we show that the complexation can be accelerated when the solution pH is changed from 13 to 7–8 in the presence of schizophyllan and polynucleotides. By this approach, we found that schizophyllan forms a complex with a yeast mRNA.
Micromonosporin A, a Novel 24‐Membered Polyene Lactam Macrolide from Micromonospora sp. Isolated from Peat Swamp Forest
Authors: Thawai Chitti , Kittakoop Prasat , Tanasupawat Somboon , Suwanborirux Khanit , Sriklung Kanlayanee , Thebtaranonth Yodhathai 
Published: April 2004

AbstractA novel 24‐membered polyene lactam macrolide, micromonosporin A (=(3E,5E,7Z,15E,17E,19E,21E)‐9,11,13‐trihydroxy‐14,19,24‐trimethyl‐1‐azacyclotetracosa‐3,5,7,15,17,19,21‐heptaen‐2‐one; 1) was isolated from the actinomycete, Micromonospora sp. strain TT1‐11, which was isolated from a very acidic peat swamp forest.
In vivo evidence suggesting a role for purine‐catabolizing enzymes in the pathogenesis of cisplatin‐induced nephrotoxicity in rats and effect of erdosteine against this toxicity
Authors: Söğüt Sadık , Kotuk Mahir , Yılmaz H. Ramazan , Ulu Ramazan , Özyurt Hüseyin , Yıldırım Zeki 
Published: April 2004

AbstractThe aim of this experimental study was to investigate the possible role of adenosine deaminase (AD) and xanthine oxidase (XO) in the pathogenesis of cisplatin‐induced nephrotoxicity and the effect of erdosteine in decreasing the toxicity. The intraperitoneal injection of cisplatin (7 mg kg−1 body weight) induced a significant increase in plasma creatinine level and blood urea nitrogen (BUN), and plasma and damaged renal tissue activities of AD and XO in rats. Co‐treatment with erdosteine (10 mg kg−1day−1) attenuated the increase in the plasma creatinine and BUN levels, and significantly prevented the increase in tissue and plasma AD and XO activities (P<0.05). The results of this study revealed that XO and AD may play an important role in the pathogenesis of cisplatin‐induced nephrotoxicity. The potent free radical scavenger erdosteine may have protective potential in this process and it will become a promising drug in the prevention of this undesired side‐effect of cisplatin, but further studies are needed to illuminate the exact protection mechanism of erdosteine against cisplatin‐induced nephrotoxicity. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of endorphin exposure at weaning on the endorphin and serotonin content of white blood cells and mast cells in adult rat
Authors: Csaba György , Kovács Péter , Pállinger Éva 
Published: April 2004

AbstractHormonal imprinting takes place perinatally at the first encounter between the developing receptor and its target hormone, resulting in the accomplishment of normal receptor development. In the presence of an excess of target hormone or the absence of it, or an excess of related molecules which can be bound by the receptor, faulty imprinting develops with life‐long consequences. In previous experiments neonatal endorphin exposure caused a decrease in endorphin and serotonin content of peritoneal mast cells of adult animals. In the present experiment 25‐day‐old (weaned) female rats received 2 μg endorphin, and the endorphin as well as serotonin content of adult mast cells and white blood cells was studied by flow cytometry and confocal microscopy. Peritoneal lymphocytes and blood monocytes contained significantly (p<0.01) less endorphin and peritoneal mast cells less serotonin (p<0.07, i.e. of questionable significance) than the untreated control. The results bring attention to the possibility of durable imprinting of differentiating cells later in life and to the durable (possibly life‐long) effect of an endorphin excess (perhaps caused by injury) manifested in the change of endorphin and serotonin content of immune cells. Copyright © 2004 John Wiley & Sons, Ltd.
Prolonged effect of an H1‐receptor blocker antihistamine on the histamine content of white blood cells and mast cells
Authors: Csaba G. , Kovács P. , Pállinger Éva 
Published: April 2004

AbstractHormonal imprinting usually takes place perinatally at the first encounter between the developing receptor and its target hormone, determining the future binding capacity of the receptor for life. Molecules similar to a hormone can cause faulty imprinting also with life‐long consequences. Hormone production of the imprinted cell is also durably influenced. In cytogenic organs imprinting can also be provoked in adulthood. At present the effect of a single terfenadine treatment in adult rats on the histamine content of peritoneal cells (lymphocytes, mast cells and the monocyte–macrophage–granulocyte group), white blood cells (lymphocytes, granulocytes, monocytes) and thymic lymphocytes was studied 3 weeks after treatment to clarify the effect of prolonged treatment with an antihistamine in adulthood.The cells were studied by flow cytometric analysis. Peritoneal mast cells contained significantly more and thymic lymphocytes significantly less histamine than controls. In the other cells the differences were not significant. The results support earlier observations on the effect of antihistamines on mast cell histamine release (inhibition) and call attention to the fact that this effect is durable (hormonal imprinting provoked in adults). Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis of 2,4‐Diaryl‐3,4‐dihydro‐2H‐naphth[2,1‐e][1,3]oxazines and Study of the Effects of the Substituents on Their Ring‐Chain Tautomerism
Authors: Szatmári István , Martinek Tamás A. , Lázár László , Fülöp Ferenc 
Published: April 2004

AbstractA number of 2‐(α‐amino‐Y‐substituted‐benzyl)‐1‐naphthol hydrochlorides were prepared by a convenient Mannich‐type aminoalkylation. 2,4‐Diaryl‐3,4‐dihydro‐2H‐naphth[2,1‐e][1,3]oxazines were prepared through the ring‐closure reactions of the starting aminonaphthols with aromatic aldehydes, which proved to furnish three‐component (ring1−open−ring2) tautomeric mixtures in CDCl3 at 300 K. The electronic effects of the 2‐aryl groups on the ratios of the ring‐chain tautomeric forms at equilibrium could be described by Equation (1). Study of the effects of substituents X and Y on the tautomeric equilibria [by the aid of the multiple linear regression analysis of Equations (2) and (3)] revealed that the trans‐chain equilibrium constants are significantly influenced by the inductive effect (σF) of substituent Y on the 4‐phenyl ring. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Electronic Effects in Olefin Oxidation by Imidoosmium(VIII) Compounds
Authors: Muñiz Kilian 
Published: April 2004

AbstractImido osmium(VIII) complexes are versatile oxidants for C−C double bond functionalisation. Despite their structural similarity with OsO4 their reactivity cannot always be compared with this seminal reagent. Detailed investigations including kinetic competition experiments are presented that uncover the electronic and steric preferences of osmium imido complexes. The different behaviour of OsO4 and its imido derivatives towards tertiary amines and diamines is clarified. Hammett correlation studies reveal that the reactivity spectrum of the respective oxidants ranges from a strongly electrophilic behaviour in the case of OsO4 to a rather nucleophilic character as encountered for OsO(NtBu)3. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
A New and Convenient Route to Optically Active 2‐Phosphoryl‐3‐oxo‐5‐alkyl/‐aryltetrahydrofurans and Their Reactions
Authors: Xu Chengfu , Zhang Yonghui , Yuan Chengye 
Published: April 2004

AbstractThe two enantiomers of 4‐hydroxy‐2‐oxo‐4‐alkyl/‐arylalkylphosphonates were prepared chemoenzymatically and converted to chiral 2‐phosphoryl‐3‐oxo‐5‐alkyl/‐aryl tetrahydrofurans using an intramolecular O−H insertion reaction catalyzed by rhodium(II) acetate. The potential biological activity of the resulting tetrahydrofurans is of much interest. The presence of the β‐ketophosphonate skeleton in these heterocycles allowed their use as substrate in the cyclic Horner−Wadsworth−Emmons reaction with aldehydes or ketones furnishing chiral α,β‐unsaturated ketones − a new class of building block in organic synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Structure Elucidation of the Highly Heterogeneous Lipid A from the Lipopolysaccharide of the Gram‐Negative Extremophile Bacterium Halomonas Magadiensis Strain 21 M1
Authors: Silipo Alba , Sturiale Luisa , Garozzo Domenico , Castro Cristina de , Lanzetta Rosa , Parrilli Michelangelo , Grant William D. , Molinaro Antonio 
Published: April 2004

AbstractHalomonas magadiensis (formerly named Halomonas magadii) is a Gram‐negative extremophilic and alkaliphilic bacterium isolated from Lake Magadi, which is located in the East African Rift Valley. Several members of the halomonad group of bacteria have been shown to inhabit the alkaline brines, including a new member, Halomonas magadiensis strain 21 M1 (NCIMB 13595), an organism that grows at high pH and relatively high salt concentration. The unusual structure of the lipid A family derived from the lipopolysaccharide of Halomonas magadiensis is reported herein. The structure was determined using chemical analysis, NMR spectroscopy and MALDI‐TOF mass spectrometry. Lipid A was also analysed after either de‐O‐acylation or dephosphorylation. The resultant mixture was very heterogeneous in fatty acid substitution, from heptaacyl to triacyl species. The various lipid A molecules obtained by the removal of one or more acyl substituents from the heptaacyl species are described below. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Angiogenesis and skin carcinomas with skull base invasion: a case–control study
Authors: Cernea Claudio R. , Ferraz Alberto R. , de Castro Inês V. , Sotto Miriam N. , Logullo Ângela F. , Bacchi Carlos E. , Potenza André S. 
Published: April 2004

AbstractBackground.Some skin carcinomas may be very aggressive. Intensity of angiogenesis, measured by intratumoral vessel density using expression of CD34, has been associated with tumor aggressiveness. In this study, the expression of CD34 in basal cell carcinomas ( BCCs) and squamous cell carcinomas (SCCs) with skull base invasion was compared with that in tumors with good outcome.Methods.Expression of CD34 was graded as mild, moderate, and intense, in 24 BCCs and 11 SCCs with skull base invasion. The control group included 23 BCCs and 10 SCCs.Results.Intense expression of CD34 was noted in 25.00% of BCCs with skull base invasion, compared with 4.35% in the control group (p = .058). Regarding SCCs, intense expression of CD34 was found in 54.55% of aggressive tumors, compared with 10.00% in the control group (p = .133).Conclusions.A trend toward denser microvascular angiogenesis was observed in both BCCs and SCCs with skull base invasion compared with less aggressive controls. © 2004 Wiley Periodicals, Inc. Head Neck 26: 396–400, 2004
{2, 3}‐perfect m‐cycle systems are equationally defined for m = 5, 7, 8, 9, and 11 only
Authors: Marzi E. M. Li , Lindner C. C. , Rania F. , Wilson R. M. 
Published: April 2004

AbstractAn m‐cycle system (S,C) of order n is said to be {2,3}‐perfect provided each pair of vertices is connected by a path of length 2 in an m‐cycle of C and a path of length 3 in an m‐cycle of C. The class of {2,3}‐perfect m‐cycle systems is said to be equationally defined provided, there exists a variety of quasigroups V with the property that a finite quasigroup (Q, $\circ$, \, /) belongs to V if and only if its multiplicative (Q, $\circ$) part can be constructed from a {2,3}‐perfect m‐cycle system using the 2‐construction (a $\circ$ a = a for all a ∈ Q and if a ≠ b, a $\circ$ b = c and b $\circ$ a = d if and only if the m‐cycle (…, d, x, a, b, y, c, …) ∈ C). The object of this paper is to show that the class of {2,3}‐perfect m‐cycle systems cannot be equationally defined for all m ≥ 10, m ≠ 11. This combined with previous results shows that {2, 3}‐perfect m‐cycle systems are equationally defined for m = 5, 7, 8, 9, and 11 only. © 2004 Wiley Periodicals, Inc.
Functional characterization of Cx43 based gap junctions during spermatogenesis
Authors: Decrouy X. , Gasc J.‐M. , Pointis G. , Segretain D. 
Published: April 2004

AbstractIn the testis, spermatogenesis is a highly regulated process that includes germ cell multiplication and differentiation supported by Sertoli cells. Gap junction intercellular communication (GJIC), that is known to play an important role in the control of cell proliferation and differentiation, allows communication between adjacent cells. Gap junctions are present within the seminiferous epithelium but the precise nature of coupled cells is not yet identified. By applying a dye‐transfer assay to testis, we demonstrated that coupling was basally located in the tubular compartment between adjacent Sertoli cells, between Sertoli cells and spermatogonia and early and late spermatocytes, but not between Sertoli cells and spermatids. Furthermore, no dye transfer occurred from germ cells to Sertoli cells. Specificity of the gap junction coupling was verified with known gap junction inhibitors such as oleamide, heptanol, and glycyrrhetinic acid. We developed a sophisticated assay that allows correlating the in vivo dye transfer with cell morphological identification and Cx43 expression. This approach demonstrated the Cx43 participation in the coupling. Interestingly Cx43 expression and dye‐coupling varied with the stages of spermatogenesis. Our results suggest that Cx43 based gap junctions form a transversal and longitudinal intercellular communication network within seminiferous tubules, and that specific communication territories are formed within the seminiferous tubules to ensure the synchronization of germ cell proliferation and differentiation. © 2003 Wiley‐Liss, Inc.
Site‐matched papillary and reticular human dermal fibroblasts differ in their release of specific growth factors/cytokines and in their interaction with keratinocytes
Authors: Sorrell J. Michael , Baber M.A. , Caplan A.I. 
Published: April 2004

AbstractThe interfollicular dermis of adult human skin is partitioned into histologically and physiologically distinct papillary and reticular zones. Each of these zones contains a unique population of fibroblasts that differ in respect to their proliferation kinetics, rates at which they contract type I collagen gels, and in their relative production of decorin and versican. Here, site‐matched papillary and reticular dermal fibroblasts couples were compared to determine whether each population interacted with keratinocytes in an equivalent or different manner. Papillary and reticular fibroblasts grown in monolayer culture differed significantly from each other in their release of keratinocyte growth factor (KGF) and granulocyte‐macrophage colony stimulating factor (GM‐CSF) into culture medium. Some matched fibroblast couples also differed in their constitutive release of interleukin‐6 (IL‐6). Papillary fibroblasts produced a higher ratio of GM‐CSF to KGF than did corresponding reticular fibroblasts. Interactions between site‐matched papillary and reticular couples were also assayed in a three‐dimensional culture system where fibroblasts and keratinocytes were randomly mixed, incorporated into type I collagen gels, and allowed to sort. Keratinocytes formed distinctive cellular masses in which the keratinocytes were organized such that the exterior most layer of cells exhibited characteristics of basal keratinocytes and the interior most cells exhibited characteristics of terminally differentiated keratinocytes. In the presence of papillary dermal fibroblasts, keratinocyte masses were highly symmetrical and cells expressed all levels of differentiation markers. In contrast, keratinocyte masses that formed in the presence of reticular fibroblasts tended to have irregular shapes, and terminal differentiation was suppressed. Furthermore, basement membrane formation was retarded in the presence of reticular cells. These studies indicate that site‐matched papillary and reticular dermal fibroblasts qualitatively differ in their support of epidermal cells, with papillary cells interacting more effectively than corresponding reticular cells. © 2003 Wiley‐Liss, Inc.
Molecular tools for a molecular medicine: analyzing genes, transcripts and proteins using padlock and proximity probes
Authors: Landegren Ulf , Schallmeiner Edith , Nilsson Mats , Fredriksson Simon , Banér Johan , Gullberg Mats , Jarvius Jonas , Gustafsdottir Sigrun , Dahl Fredrik , Söderberg Ola , Ericsson Olle , Stenberg Johan 
Published: April 2004

AbstractProcedures and reagents are needed to specifically detect all the macromolecules that are being identified in the course of genome projects. We discuss how this challenge may be met using a set of ligation‐based reagents termed padlock probes and proximity ligation probes. These probes include elements with affinity for specific nucleic acid and protein molecules, respectively, along with unique identifier DNA sequence elements that encode the identity of the recognized target molecules. The information content of DNA strands that form in the detection reactions are recorded after amplification, allowing the recognized target molecules to be identified. The procedures permit highly specific solution‐phase or localized analyses of large sets of target molecules as required in future molecular analyses. Copyright © 2004 John Wiley & Sons, Ltd.
Unique interaction of scorpion toxins with the hERG channel
Authors: Korolkova Yuliya V. , Tseng Gea‐Ny , Grishin Eugene V. 
Published: April 2004

AbstractERG potassium channels specify one component of the delayed rectifier in the heart and are likely to play an important functional role in other excitable cells. Compared to other K+ channels, the human ERG (hERG) channel possesses an unusually long S5‐P linker that presumably forms an alpha‐helix important for channel function. hERG‐specific toxins bind to the outer mouth of the hERG channel. Channel residues in the middle of the S5‐P linker and at the pore entrance are critical for toxin binding. One of these scorpion toxins is BeKm‐1. Residues critical for BeKm‐1 binding to the hERG channel are located in the alpha‐helix and the following loop, whereas the ‘traditional’ interaction surface of other short scorpion toxins is formed by residues on the β‐sheet. This unique localization of BeKm‐1's interaction surface and its specific action on the hERG channel suggest a unique outer mouth structure of the hERG channel. We used the mutant cycle analysis approach to define contacts in the toxin–channel complex. This information provides critical constraints and is important for molecular modeling of the hERG pore structure. Copyright © 2004 John Wiley & Sons, Ltd.
Proteins, recognition networks and developing interfaces for macromolecular biosensing
Authors: Sergi Mauro , Zurawski John , Cocklin Simon , Chaiken Irwin 
Published: April 2004

AbstractGenomics and proteomics discovery is leading to the identification of all proteins and to the opportunity, and challenge, to reveal the protein recognition networks that drive virtually all biological processes. Over the past decade, biosensors have emerged as a key technology for detection and analysis of biomolecular interactions. An important limitation in developing such biosensors is that the focus has been mainly on sensor platforms, the transducing hardware that converts interaction signals into recorded data, without adequately considering the role of molecular interfaces, the elements of sensors that interact with analytes to produce signals. We have investigated this alternative focus by identifying and, where necessary, designing molecular interfaces that will more effectively drive new biosensor development and utilization in biomedical and biotechnological investigations. Here we describe our recent studies of coiled coil and lipid bilayer interfaces and the potential to use these to expand sensing technologies for multiplexed target detection and analysis in increasingly biologically relevant membrane like environments. Copyright © 2004 John Wiley & Sons, Ltd.
On‐chip single‐cell‐based microcultivation method for analysis of genetic information and epigenetic correlation of cells
Authors: Yasuda Kenji 
Published: April 2004

AbstractWe have developed an on‐chip single‐cell based microcultivation method for analyzing the variability of genetic information stored in single cells and their epigenetic correlations. The method uses four systems: an on‐chip cell sorter for purifying the cells in a non‐destructive manner; an on‐chip single‐cell cultivation chip for isolating single cells; an on‐chip agarose microchamber system for constructive cell‐cell network formation during cultivation; and an on‐chip single‐cell‐based expression analysis system. Using these systems, we could measure the variability of prokaryotic cells and eukaryotic cells having the same DNA and found that, although prokaryotic cells have a large variability in their interdivision times, sister eukaryotic cells having the same DNA synchronized well. We also measured the dynamics of synchronization of beating cardiac myocytes and found that two isolated cells synchronize by one cell following the other after a short pause in beating. These results showed the potential of the on‐chip microcultivation method's constructive approach to analyzing cell systems. Copyright © 2004 John Wiley & Sons, Ltd.
Supramolecular architectures featuring stereoisomeric cluster complexes of the [Re6(μ3‐Se)8]2+ core
Authors: Selby Hugh D. , Roland Bryan K. , Cole Jenine R. , Zheng Zhiping 
Published: April 2004

AbstractThe [Re6(μ3‐Se)8]2+ core‐containing cluster complexes of the general formula [Re6(μ3‐Se)8(PEt3)4L2]2+ (both trans‐ and cis‐isomers) site‐differentiated with inert PEt3 and functional L ligands that are capable of hydrogen bonding or secondary (with respect to primary coordination with the cluster core) metal‐ligand coordination interactions have been prepared. The applications of such stereospecific cluster isomers as building blocks for supramolecular construction have been studied. A great variety of multicluster arrays mediated by intercluster hydrogen bonding or cluster ligand coordination with secondary metal ions have been obtained and structurally characterized. The findings from this research clearly establish the superior utility of these novel building blocks for the creation of structurally sophisticated architectures and possibly functional materials.