bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformational studies of hexapeptides containing two dehydroamino acid residues in positions 2 and 5 in peptide chain
Authors: Latajka Rafal , Jewginski Michal , Makowski Maciej , Krezel Artur , Paluch Slawomir 
Published: March 2008

AbstractConformational preferences of a group of hexapeptides containing two dehydroamino acid residues in Positions 2 and 5 in peptide chain were investigated by means of spectroscopic methods (NMR and CD) and theoretical calculations. In the case of dimethylsulfoxide (DMSO) solution, only peptide with free N‐termini adopted rigid 310‐helical conformation, for the rest of examined peptides extended and “zig‐zag” conformers were predominant. CD measurements showed that only in chloroform solution the conformational freedom of investigated peptides was restricted. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 691–699, 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
Lipopolysaccharide‐induced monocyte chemotactic protein‐1 is enhanced by suppression of nitric oxide production, which depends on poor CD14 expression on the surface of skeletal muscle
Authors: Kawanishi Noriaki , Tanaka Yohei , Kato Yasuko , Shiva Daisuke , Yano Hiromi 
Published: March 2008

AbstractIt is known that lipopolysaccharide (LPS)‐induced monocyte chemotactic protein (MCP)‐1 secretion from tissues recruits monocytes from the circulation, but the mechanism of the LPS‐induced MCP‐1 production in skeletal muscle is largely unexplained. To clarify the effect of LPS on MCP‐1 production in skeletal muscle cells, C2C12 cells from a mouse skeletal muscle cell line, and RAW 264.7 cells from a mouse macrophage cell line, were used to assess production of LPS‐induced MCP‐1, nitric oxide (NO) and interferon (IFN)‐β. In addition, we evaluated inducible NO synthases (iNOS) mRNA expression using RT‐PCR, and cell surface expression of CD14 and toll‐like receptor (TLR) 4 using flow cytometry. In C2C12 cells, LPS stimulation increased MCP‐1 production (p < 0.01), but combined treatment with LPS and NO inducer, diethylammonium (Z)‐1‐(N,N‐diethylamino) diazen‐1‐ium‐1,2‐diolate (NONOate), significantly inhibited its production (p < 0.01). LPS stimulation neither induced production of NO nor of IFN‐β, which is an NO inducer. Recombinant IFN‐β stimulation, on the other hand, enhanced LPS‐induced NO production (p < 0.01). Interestingly, we found that surface expression of CD14, which regulates IFN‐β production, in C2C12 cells was much lower than that in RAW 264.7 cells, although TLR4 expression on C2C12 cells was similar to that on RAW 264.7 cells. These data suggest that the reduced NO production in response to LPS may depend on low expression of CD14 on the cell surface of skeletal muscle, and that it may enhance LPS‐induced MCP‐1 production. Together, these functions of skeletal muscle could decrease the risk of bacterial infection by recruitment of monocytes. Copyright © 2008 John Wiley & Sons, Ltd.
Self‐Organization of Dendritic Supermolecules, Based on Isocyanide–Gold(I), –Copper(I), –Palladium(II), and –Platinum(II) Complexes, into Micellar Cubic Mesophases
Authors: Coco Silverio , Cordovilla Carlos , Donnio Bertrand , Espinet Pablo , García‐Casas María Jesús , Guillon Daniel 
Published: March 2008

AbstractFirst‐ and second‐generation dendrimers with an isocyanide group as the focal functional point (CN‐Gn; n: 1,2) and their corresponding organometallic complexes [MCl(CN‐Gn)] (M: Au, Cu), [{CuCl(CN‐Gn)2}2], and trans‐[MI2(CN‐Gn)2] (M: Pd, Pt) have been synthesized. The free ligands and the first‐generation complexes do not show mesogenic behavior, but all of the second‐generation complexes display a thermotropic micellar cubic mesophase, over a large temperature range, and some of them directly at room temperature. The structure of the mesophase consists of the packing of two, discrete polyhedral micellar aggregates in a three‐dimensional cubic Im$\bar 3$m lattice.
68Ga‐PET: a powerful generator‐based alternative to cyclotron‐based PET radiopharmaceuticals
Authors: Fani Melpomeni , André João P. , Maecke Helmut R. 
Published: March 2008

AbstractPET (positron emission tomography) is a powerful diagnostic and imaging technique which requires short‐lived positron emitting isotopes. The most commonly used are accelerator‐produced 11C and 18F. An alternative is the use of metallic positron emitters. Among them 68Ga deserves special attention because of its availability from long‐lived 68Ge/68Ga generator systems which render 68Ga radiopharmacy independent of an onsite cyclotron. The coordination chemistry of Ga3+ is dominated by its hard acid character. A variety of mono‐ and bifunctional chelators have been developed which allow the formation of stable 68Ga3+complexes and convenient coupling to biomolecules. 68Ga coupling to small biomolecules is potentially an alternative to 18F‐ and 11C‐based radiopharmacy. In particular, peptides targeting G‐protein coupled receptors overexpressed on human tumour cells have shown preclinically and clinically high and specific tumour uptake. Kit‐formulated precursors along with the generator may be provided, similar to the 99Mo/99mTc‐based radiopharmacy, still the mainstay of nuclear medicine. Copyright © 2008 John Wiley & Sons, Ltd.
Functional imaging of neuroendocrine tumors with combined PET/CT using 68Ga‐DOTATATE (DOTA‐DPhe1,Tyr3‐octreotate) and 18F‐FDG
Authors: Kayani Irfan , Bomanji Jamshed B. , Groves Ashley , Conway Gerard , Gacinovic Sveto , Win Thida , Dickson John , Caplin Martyn , Ell Peter Joseph 
Published: March 2008

AbstractBACKGROUND.The aim was to assess the relevant distribution of the novel PET tracer 68Ga‐DOTATATE in neuroendocrine tumors (NETs) with combined positron emission tomography / computed tomography (PET/CT) and compare its performance with that of 18F‐FDG PET/CT.METHODS.The imaging findings with 68Ga‐DOTATATE and 18F‐FDG on 38 consecutive patients with a diagnosis of primary or recurrent NET were compared and correlated with tumor grade on histology based on ki67 and mitotic index.RESULTS.The sensitivity of 68Ga‐DOTATATE PET/CT was 82% (31 of 38) and that of 18F‐FDG PET/CT was 66% (25 of 38). The sensitivity of combined 68Ga‐DOTATATE and 18F‐FDG PET/CT was 92% (35 of 38). There was greater uptake of 68Ga‐DOTATATE than 18F‐FDG in low‐grade NET (median SUV 29 vs 2.9, P < .001). In high‐grade NET there was higher uptake of 18F‐FDG over 68Ga‐DOTATATE (median SUV 11.7 vs 4.4, P = .03). There was a significant correlation with predominant tumor uptake of 68Ga‐DOTATATE or 18F‐FDG and tumor grade on histology (P < .0001).CONCLUSIONS.68Ga‐DOTATATE PET/CT is a useful novel imaging modality for NETs and is superior to 18F‐FDG for imaging well‐differentiated NET. Functional imaging with both 68Ga‐DOTATATE and 18F‐FDG has potential for a more comprehensive tumor assessment in intermediate‐ and high‐grade tumors. Cancer 2008. ©2008 American Cancer Society.
Antiandrogen withdrawal in castrate‐refractory prostate cancer
Authors: Sartor A. Oliver , Tangen Catherine M. , Hussain Maha H. A. , Eisenberger Mario A. , Parab Minoti , Fontana Joseph A. , Chapman Robert A. , Mills Glenn M. , Raghavan Derek , Crawford E. David 
Published: March 2008

AbstractBACKGROUND.Antiandrogen withdrawal is a potential therapeutic maneuver for patients with progressive prostate cancer. This study was designed to examine antiandrogen withdrawal effects within the context of a large multi‐institutional prospective trial.METHODS.Eligibility criteria included progressive prostate adenocarcinoma despite combined androgen blockade. Eligible patients received prior initial treatment with an antiandrogen plus orchiectomy or luteinizing hormone‐releasing hormone (LHRH) agonist. Patients were stratified according to type of antiandrogen, type of progression (prostate‐specific antigen [PSA] or radiographic), presence or absence of metastatic disease, and prior LHRH agonist versus surgical castration.RESULTS.A total of 210 eligible and evaluable patients had a median follow‐up of 5.0 years; 64% of patients previously received flutamide, 32% bicalutamide, and 3% nilutamide. Of the 210 patients, 21% of patients had confirmed PSA decreases of ≥50% (95% CI, 16% to 27%). No radiographic responses were recorded. Median progression‐free survival (PFS) was 3 months (95% CI, 2 months to 4 months); however, 19% had 12‐month or greater progression‐free intervals. Median overall survival (OS) after antiandrogen withdrawal was 22 months (20 and 40 months for those with and without radiographic evidence of metastatic disease, respectively). Multivariate analyses indicated that longer duration of antiandrogen use, lower PSA at baseline, and PSA‐only progression at study entry were associated with both longer PFS and OS. Longer antiandrogen use was the only significant predictor of PSA response.CONCLUSIONS.These data indicate a relatively modest rate of PSA response in patients who were undergoing antiandrogen withdrawal; however, PFS can be relatively prolonged (≥1 year) in approximately 19% of patients. Cancer 2008. © 2008 American Cancer Society.
Experimental study on the extraction and distribution of textual domain keywords
Authors: Luo Xiangfeng , Fang Ning , Xu Weimin , Yu Sheng , Yan Kai , Xiao Huizhe 
Published: March 2008

AbstractDomain keywords of text play a primary role in text classifying, clustering and personalized services. This paper proposes a term frequency inverse document frequency (TFIDF) based method called TDDF (TFIDF direct document frequency of domain) to extract domain keywords from multi‐texts. First, we discuss the optimal parameters of TFIDF, which are used to extract textual keywords and domain keywords. Second, TDDF is proposed to extract domain keywords from multi‐texts, which takes document frequency of domain into account. Finally, the distribution of domain keywords on scientific texts is studied. Experiments and applications show that TDDF is more effective than the optimal TFIDF in the extraction of domain keywords. Domain keywords accord with normal distribution on a single text after deleting the ubiquitous domain keywords. Copyright © 2008 John Wiley & Sons, Ltd.
From synapses to behavior: Development of a sensory‐motor circuit in the leech
Authors: Marin‐Burgin Antonia , Kristan William B. , French Kathleen A. 
Published: March 2008

AbstractThe development of neuronal circuits has been advanced greatly by the use of imaging techniques that reveal the activity of neurons during the period when they are constructing synapses and forming circuits. This review focuses on experiments performed in leech embryos to characterize the development of a neuronal circuit that produces a simple segmental behavior called “local bending.” The experiments combined electrophysiology, anatomy, and FRET‐based voltage‐sensitive dyes (VSDs). The VSDs offered two major advantages in these experiments: they allowed us to record simultaneously the activity of many neurons, and unlike other imaging techniques, they revealed inhibition as well as excitation. The results indicated that connections within the circuit are formed in a predictable sequence: initially neurons in the circuit are connected by electrical synapses, forming a network that itself generates an embryonic behavior and prefigures the adult circuit; later chemical synapses, including inhibitory connections, appear, “sculpting” the circuit to generate a different, mature behavior. In this developmental process, some of the electrical connections are completely replaced by chemical synapses, others are maintained into adulthood, and still others persist and share their targets with chemical synaptic connections. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
Imaging second messenger dynamics in developing neural circuits
Authors: Dunn Timothy A. , Feller Marla B. 
Published: March 2008

AbstractA characteristic feature of developing neural circuits is that they are spontaneously active. There are several examples, including the retina, spinal cord, and hippocampus, where spontaneous activity is highly correlated among neighboring cells, with large depolarizing events occurring with a periodicity on the order of minutes. One likely mechanism by which neurons can “decode” these slow oscillations is through activation of second messenger cascades that either influence transcriptional activity or drive posttranslational modifications. Here, we describe recent experiments where imaging has been used to characterize slow oscillations in the cAMP/PKA second messenger cascade in retinal neurons. We review the latest techniques in imaging this specific second messenger cascade, its intimate relationship with changes in intracellular calcium concentration, and several hypotheses regarding its role in neurodevelopment. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
Molecular MALDI imaging: An emerging technology for neuroscience studies
Authors: Wisztorski Maxence , Croix Dominique , Macagno Eduardo , Fournier Isabelle , Salzet Michel 
Published: March 2008

AbstractMass spectrometry (MS) has become an essential tool for the detection, identification, and characterization of the molecular components of biological processes, such as those responsible for the dynamic properties of the nervous system. Generally, the application of these powerful techniques requires the destruction of the specimen under study, but recent technological advances have made it possible to apply the matrix‐assisted laser desorption/ionization (MALDI) MS technique directly to tissue sections. The major advantage of direct MALDI analysis is that it enables the acquisition of local molecular expression profiles, while maintaining the topographic integrity of the tissue and avoiding time‐consuming extraction, purification, and separation steps, which have the potential for introducing artifacts. With automation and the ability to display complex spectral data using imaging software, it is now possible to create multiple 2D maps of selected biomolecules in register with tissue sections, a method now known as MALDI Imaging, or MSI (for Mass Spectrometry Imaging). This creates, for example, an opportunity to correlate functional states, determined a priori with live recording or imaging, with the corresponding molecular maps obtained at the time the tissue is frozen and analyzed with MSI. We review the increasing application of MALDI Imaging to the analysis of molecular distributions of proteins and peptides in nervous tissues of both vertebrates and invertebrates, focusing in particular on recent studies of neurodegenerative diseases and early efforts to implement assays of neuronal development. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
Local control of photovoltaic distributed generation for voltage regulation in LV distribution networks and simulation tools
Authors: Conti Stefania , Greco Andrea Maria , Raiti Salvatore 
Published: March 2008

AbstractThe increasing connection of distributed generation (DG) in distribution networks may affect the quality of power offered to customers. One of the most relevant issues is the possibility to have unacceptable voltage rise at the point of common coupling (PCC). This work focuses on the problem of voltage control in LV distribution networks in the presence of photovoltaic (PV) DG. The paper presents a local voltage control method based on PV generation curtailment as an alternative to ‘on/off’ operation, typically required by distribution operators to prevent overvoltage at the PCCs by means of overvoltage protections embedded in the PV unit. To show the effect of the proposed local voltage control, a simulation tool, developed in MATLAB®–Simulink® environment, is presented. Appropriate numerical models for network components and PV generators are provided in order to describe computer simulation implementation of the test system. The final results show that the control system is able to adjust the active power output of local generators to keep the voltage profile of the feeder, in which DG is installed, within the range allowed by Norm EN 50160. Copyright © 2008 John Wiley & Sons, Ltd.
Microsomal epoxide hydrolase genotypes and the risk for head and neck cancer
Authors: Lacko Martin , Roelofs Hennie M. J. , te Morsche Rene H. M. , Voogd Adri C. , Oude Ophuis Michael B. , Peters Wilbert H. M. , Manni Johannes J. 
Published: March 2008

AbstractBackground.Microsomal epoxide hydrolase (mEH) is an enzyme involved in the metabolism of (pre)carcinogens in tobacco smoke. We investigated whether functional genetic polymorphisms in mEH may have a risk‐modifying effect on head and neck carcinogenesis.Methods.Blood from 429 patients with oral, pharyngeal, and laryngeal carcinoma and 419 healthy subjects was investigated for mEH polymorphisms.Results.Logistic regression analysis did not show differences in mEH genotype distributions between patients and controls, when categorized according to predicted mEH enzyme activity. Also no differences were found when evaluated according to tumor localization, sex, or tobacco consumption. A significantly higher incidence of the 139Arg/Arg variant was found in patients with hypopharyngeal carcinoma compared with controls (OR = 4.39, 95% CI = 1.45 to 13.35).Conclusion.In contrast to earlier reports, we could not demonstrate a risk‐modifying effect of genetic polymorphisms in mEH on head and neck carcinogenesis, except for the predicted high activity variant in patients with hypopharyngeal carcinoma. © 2008 Wiley Periodicals, Inc. Head Neck 2008
Photo‐crosslinkable, biomimetic, and thermo‐sensitive pluronic grafted hyaluronic acid copolymers for injectable delivery of chondrocytes
Authors: Lee Hyukjin , Park Tae Gwan 
Published: March 2008

AbstractHyaluronic acid (HA) grafted with Pluronic F127 copolymer was used as biomimetic hydrogels for cell delivery. The graft copolymer was synthesized by conjugating amine end‐capped Pluronic F127 to carboxylic groups of HA using coupling agents. The synthesized HA‐g‐Pluronic exhibited thermo‐sensitive sol–gel transition behaviors over the temperature range of 20–40°C. HA‐g‐Pluronic copolymers with vinyl groups were photo‐crosslinked to prepare more robust hydrogels for cell cultivation. For improved cellular adhesion and proliferation, cell adhesive peptide (Arg‐Gly‐Asp (RGD)) was additionally conjugated to the HA backbone. The resultant thermo‐sensitive, photocrosslinkable, and RGD modified HA‐g‐Pluronic copolymers were used to encapsulate and cultivate bovine chondrocytes in vitro. A tissue containing cartilage‐like components such as GAG and type II collagen was successfully produced within the hydrogels, indicating that the synthesized HA‐g‐Pluronic copolymers can be potentially used as an injectable cell carrier. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Induction correction model for rotation of two or three dihedral angles
Authors: Holt Asbjørn , Karlstrøm Gunnar 
Published: March 2008

AbstractIn a previous work we have introduced an intramolecular induction correction model. In this work we have used the model to calculate the total dipol moment of six molecules as a function of two or three dihedral angles that are simultaneously varied in the molecules. It is found that the induction model behaves very well for the systems studied when compared with a regular force field model where fixed charges and dipoles are rotated along with the atoms of the molecules. This suggests that the proposed induction correction model can be used to model systems containing several dihedral angles around which rotations are performed. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008
Inhibition of SNAP25 expression by HIV‐1 Tat involves the activity of mir‐128a
Authors: Eletto Davide , Russo Giuseppe , Passiatore Giovanni , Del Valle Luis , Giordano Antonio , Khalili Kamel , Gualco Elisa , Peruzzi Francesca 
Published: March 2008

AbstractMicroRNAs (miRs) are short endogenous RNAs that regulate gene expression by incomplete pairing with messenger RNAs. An increasing number of studies show that mammalian microRNAs play fundamental roles in various aspects of cellular function including differentiation, proliferation, and cell death. Recent findings demonstrating the presence of microRNAs in mature neuronal dendrites suggest their possible involvement in controlling local protein translation and synaptic function. HIV‐1 Encephalopathy (HIVE) is a manifestation of HIV‐1 infection that often results in neuronal damage and dysfunction. While neurons are rarely, if ever, infected by HIV‐1, they are exposed to cytotoxic viral and cellular factors including the HIV‐1 transactivating factor Tat. In this study, we show that Tat deregulates expression levels of selected microRNAs, including the neuronal mir‐128, in primary cortical neurons. We further show that mir‐128a inhibits expression of the pre‐synaptic protein SNAP25, whereas the anti‐mir‐128a partially restores Tat/mir‐128a‐induced downregulation of SNAP25 expression. Altogether, our data provide a novel mechanism by which HIV‐Tat perturbs neuronal activity. J. Cell. Physiol. 216: 764–770, 2008, © 2008 Wiley‐Liss, Inc.
A fusogenic segment of glycoprotein H from herpes simplex virus enhances transfection efficiency of cationic liposomes
Authors: Tu Ying , Kim Ji‐seon 
Published: March 2008

AbstractBackgroundLow cellular uptake and endosomal escape are regarded as major limitations for nonviral gene delivery. In the present study, we use cationic liposomes incorporating fusogenic peptides from glycoprotein H of herpes simplex virus to improve cellular internalization and endosomal release of cationic liposome‐DNA complexes.MethodsA synthetic analogue of a fusogenic peptide domain in glycoprotein H from herpes simplex virus was evaluated for in vitro gene delivery. The fusogenicity of the peptide was evaluated by a lipid mixing assay in neutral and acidic environments. The influence of the peptide on cellular internalization and subcellular distribution of Lipofectamine‐pGL3 complexes were evaluated by flow cytometry, fluorescence microscopy, and confocal laser scanning microscopy. The effect of the peptide on transfection efficiency of cationic liposomes was also evaluated by luciferase assay in human cell lines.ResultsA pH‐sensitive fusogenicity of the wild‐type peptide was observed. In the lipid mixing assay, the peptide mediated 80% membrane fusion at pH 7.4 at a 0.05 : 1 (peptide : lipid) mole ratio. At pH 4.5, 100% of membrane fusion was observed at a 0.005 : 1 ratio. Adding the peptide to Lipofectamine‐pGL3 complexes significantly increased cellular uptake and, thus, increased transgene expression up to 30‐fold in human cell lines. Nuclear localization of the DNA complex by the fusogenic peptide was observed by confocal microscopy.ConclusionsA synthetic analogue of a fusogenic peptide domain from herpes simplex virus has been proven to improve cationic lipid‐mediated transfection in vitro. The application of this fusogenic peptide will lead to improved strategies for transfection and successful gene therapy. Copyright © 2008 John Wiley & Sons, Ltd.