bluuebunny/crossref_metadata_2025_split huggingface dataset:
The New Energetic Compounds 1,5‐Diaminotetrazolium and 5‐Amino‐1‐methyltetrazolium Dinitramide – Synthesis, Characterization and Testing
Authors: Klapötke Thomas M. , Stierstorfer Jörg 
Published: May 2008

AbstractThe new energetic compounds 1,5‐diamino‐1H‐tetrazol‐4‐ium dinitramide (1) and 5‐amino‐1‐methyl‐1H‐tetrazol‐4‐ium dinitramide (2) were synthesized by the reaction of potassium dinitramide with 1,5‐diamino‐1H‐tetrazolium perchlorate and 5‐amino‐1‐methyl‐1H‐tetrazolium perchlorate, respectively. Both compounds were fully characterized by single‐crystal X‐ray diffraction, IR and Raman spectroscopy, multinuclear (1H, 13C, 14N, 15N) NMR spectroscopy, differential scanning calorimetry, and mass spectrometry. In addition, their sensitivities towards impact, friction, and electrical discharge were investigated. The heats of formation were calculated (CBS‐4M) in an extensive computational study. The detonation parameters of 1 and 2 were calculated by using the EXPLO5 software. The calculations yielded auspicious values for potential application as highly explosive compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Chromosome aberrations and telomere length modulation in bone marrow and spleen cells of melphalan‐treated p53+/− mice
Authors: Sgura Antonella , De Amicis Andrea , Stronati Laura , Cinelli Serena , Pacchierotti Francesca , Tanzarella Caterina 
Published: May 2008

AbstractThe p53 gene regulates cell cycle and apoptotic pathways after induction of DNA damage. Telomeres, capping chromosome ends, are involved in maintaining chromosome stability; alterations of their length have been related to increased levels of chromosomal aberrations. To study a possible interaction between chromosome aberrations, telomere dysfunction, and p53, we investigated via painting analysis the induction and persistence of chromosome aberrations in bone marrow and spleen cells of p53+/− (and wild type) mice exposed for 4, 13, or 26 weeks to 2 mg/kg melphalan (MLP), a chemotherapeutic agent with carcinogenic potential. In addition, telomere length was evaluated in bone marrow cells by quantitative fluorescence in situ hybridization (Q‐FISH). Chromosome aberrations were significantly increased in both tissues after MLP treatment. The p53 genotype did not influence the response of spleen cells, whereas a slight but significant increase of the aberration frequency was measured in the bone marrow of p53+/− mice exposed to MLP for 13 weeks with respect to the level detected in the matched wild‐type group. The main finding of our still preliminary results on telomere length modulation was again a difference between the two genotypes. In bone marrow cells of wild‐type mice, MLP treatment was associated with telomere shortening, while in p53+/− mice telomere elongation was the prevalent response to MLP exposure. In agreement with previous literature data, our in vivo study suggests that even the lack of a single functional copy of the p53 gene might have an impact on the quantity and quality of chromosome alterations induced in cycling cells by a clastogenic exposure. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Brief novelty exposure facilitates dentate gyrus LTP in aged rats
Authors: Sierra‐Mercado Demetrio , Dieguez Dario , Barea‐Rodriguez Edwin J. 
Published: May 2008

AbstractAging is associated with a decreased capacity for dentate gyrus (DG) granule cell depolarization as well as reduced perforant path activation. Although it is well established that the maintenance of DG long‐term potentiation (LTP) over days is impaired in aged, as compared to young animals, the threshold for inducing this LTP has never been investigated in aged, awake animals. In addition, although exposure to novelty prior to θ‐burst stimulation (TBS) increases both the induction and longevity of DG LTP in adult rats, the effects of exposure to novelty on LTP in aged rats have never been investigated. Here, we report that although TBS delivered in the home cage induces robust and long‐lasting DG LTP in young rats, TBS fails to induce DG LTP in aged rats. Interestingly, delivery of TBS to aged rats exploring novel environments induces robust and long‐lasting LTP, with the induction, but not the longevity, of this LTP being similar in magnitude to that observed in young rats delivered TBS in the home cage. These results indicate that although TBS‐induced DG LTP is impaired in aged, as compared to young rats, TBS during exploration of novel environments is sufficient to rescue age‐related deficits in DG LTP. We discuss these observations in the context of previous findings suggesting that the facilitation of LTP by exposure to novel environments results as a consequence of reduced network inhibition in the DG and we suggest that, in spite of age‐related changes in the DG, this capacity persists in aged rats and represents a nondietary and nonpharmacological way to facilitate DG LTP during aging. © 2008 Wiley‐Liss, Inc.
Effects of aging on agmatine levels in memory‐associated brain structures
Authors: Liu Ping , Chary Sree , Devaraj Renuka , Jing Yu , Darlington Cynthia L. , Smith Paul F. , Tucker Ian G. , Zhang Hu 
Published: May 2008

AbstractAgmatine is a metabolite of L‐arginine by arginine decarboxylase. Recent evidence suggests that it exists in mammalian brain and is a novel neurotransmitter. The present study measured agmatine levels in several memory‐associated brain structures in aged (24‐month‐old), middle‐aged (12‐month‐old), and young (4‐month‐old) male Sprague Dawley rats using liquid chromatography/mass spectrometry. Agmatine levels were significantly decreased in the CA1, but increased in the CA2/3 and dentate gyrus, subregions of the hippocampus in aged and middle‐aged rats relative to the young adults. In the prefrontal cortex, a dramatic decrease in agmatine level was found in aged rats as compared with middle‐aged and young rats. There were significantly increased levels of agmatine in the entorhinal and perirhinal cortices in aged relative to middle‐aged and young rats. In the postrhinal and temporal cortices, agmatine levels were significantly increased in aged and middle‐aged rats as compared with young adults. The present findings, for the first time, demonstrate age‐related changes in agmatine levels in memory‐associated brain structures and raise a novel issue of the potential involvement of agmatine in the aging process. © 2008 Wiley‐Liss, Inc.
Distinct, but compensatory roles of PAK1 and PAK3 in spine morphogenesis
Authors: Boda Bernadett , Jourdain Lorena , Muller Dominique 
Published: May 2008

AbstractPAK1 and PAK3 belong to a family of protein kinases that are effectors of small Rho GTPases. In humans, mutations of PAK3 have been associated with mental retardation and result in in vitro studies in defects of spine morphogenesis. The functional specificities of PAK1 and PAK3 remain, however, unclear. Here, we investigated using loss and gain of function experiments how PAK1 and PAK3 affect spine morphology in hippocampal slice cultures. We find that while knockdown of PAK3 is associated with an increase in thin, elongated, immature‐type spines, downregulation of PAK1 does not alter spine morphology. Conversely, expression of a constitutively active form of PAK3 remains without effect, while expression of constitutively active PAK1 results in the formation of spines with smaller head diameters. Interestingly, expression of constitutively active PAK1 can rescue the long spine phenotype induced by suppression of PAK3. We conclude that while PAK1 and PAK3 share distinct roles in the regulation of spine morphogenesis, their activity may overlap allowing the compensation of the PAK3 deficit by PAK1. This result opens interesting perspectives in the context of reversing the spine defects associated with PAK3 mutations. © 2008 Wiley‐Liss, Inc.
Is α‐lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways that promote endogenous antioxidant capacity
Authors: Petersen Shay Kate , Moreau Régis F. , Smith Eric J. , Hagen Tory M. 
Published: May 2008

AbstractThe chemical reduction and oxidation (redox) properties of α‐lipoic acid (LA) suggest that it may have potent antioxidant potential. A significant number of studies now show that LA and its reduced form, dihydrolipoic acid (DHLA), directly scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) species and protect cells against a host of insults where oxidative stress is part of the underlying etiology. However, owing to its limited and transient accumulation in tissues following oral intake, the efficacy of nonprotein‐bound LA to function as a physiological antioxidant has been questioned. Herein, we review the evidence that the micronutrient functions of LA may be more as an effector of important cellular stress response pathways that ultimately influence endogenous cellular antioxidant levels and reduce proinflammatory mechanisms. This would promote a sustained improvement in cellular resistance to pathologies where oxidative stress is involved, which would not be forthcoming if LA solely acted as a transient ROS scavenger. © 2008 IUBMB IUBMB Life, 60(6): 362–367, 2008
Bcl‐2 family proteins: The sentinels of the mitochondrial apoptosis pathway
Authors: Wong W. Wei‐Lynn , Puthalakath Hamsa 
Published: May 2008

AbstractBcl‐2 family members are the arbiters of mitochondrial apoptotic pathway, which is conserved through evolution. The stoichiometry of pro‐ versus antiapoptotic Bcl‐2 family members in the cell determines whether the cell lives or dies. This fine balance is regulated at the transcriptional or posttranslational level in response to various cellular cues. These signals are transmitted through the upstream molecules in the pathway, that is, the BH3‐only molecules that results in the activation of the adaptor molecules, Bax and Bak, at the mitochondrial surface ensuing mitochondrial dysfunction and apoptosis. Understanding the activation process offers a great potential in the therapeutic intervention of many diseases such as cancer and autoimmune disorders. © 2008 IUBMB IUBMB Life, 60(6): 390–397, 2008
Prosaposin is an AR‐target gene and its neurotrophic domain upregulates AR expression and activity in prostate stromal cells
Authors: Koochekpour S. , Lee T.‐J. , Sun Y. , Hu S. , Grabowski G.A. , Liu Z. , Garay J. 
Published: May 2008

AbstractRecent studies have introduced prosaposin (PSAP) as a pleiotrophic growth factor for prostate cancer (PCa). We have previously reported that PSAP or one of its known active molecular derivatives, saposin C functions as an androgen‐agonist and androgen‐regulated gene (ARG) for androgen‐sensitive (AS) PCa cell lines. Due to the potential significance of androgen receptor (AR)‐expressing stroma in PCa, we evaluated a possible bi‐directional paracrine regulatory interactions between DHT and PSAP in AR‐positive prostate stromal (PrSt) cells. We report that saposin C in a ligand‐independent manner increased AR expression, its nuclear content, and tyrosine phosphorylation. DHT treatment of PrSt cells increased PSAP expression. We also demonstrated both serum‐ and androgen‐inducibility of a previously characterized hormone‐responsive element (HRE) located in the proximal region of PSAP promoter. In addition, conditioned‐media derived from PrSt cells and bone fibroblasts (i.e., MSF) differentially increased PSAP‐promoter activity in androgen‐independent (AI) PC‐3 and AS LNCaP cells. Our data for the first time demonstrate that not only saposin C or PSAP regulates AR expression/activity, but also function as an ARG in PrSt. Ligand‐independent activation of AR by PSAP or saposin C in PCa and stromal cells may contribute not only to prostate carcinogenesis at an early stage, but also in AI progression of the disease in an androgen‐deprived tumor microenvironment. J. Cell. Biochem. 104: 2272–2285, 2008. © 2008 Wiley‐Liss, Inc.
Neutralizing monoclonal antibody to human connective tissue growth factor ameliorates transforming growth factor‐β‐induced mouse fibrosis
Authors: Ikawa Yuka , Ng Poh‐Sing , Endo Koki , Kondo Miki , Chujo Sonoko , Ishida Wataru , Shirasaki Fumiaki , Fujimoto Manabu , Takehara Kazuhiko 
Published: May 2008

AbstractSkin fibrotic disorders such as systemic sclerosis (SSc) are characterized by an excessive accumulation of extracellular matrix (ECM) and are understood to develop under the influence of fibrogenic growth factors. To better understand the detailed mechanisms of persistent fibrosis in SSc, we have previously established an animal model of skin fibrosis induced by exogenous application of growth factors. In this model, transforming growth factor‐β (TGF‐β) transiently induced subcutaneous fibrosis and serial injections of connective tissue growth factor (CTGF) after TGF‐β caused persistent fibrosis. These results suggest that CTGF plays an important role in the development of persistent skin fibrosis and that CTGF may be a potential and specific therapeutic target in skin fibrosis. Therefore, the aim of the current study is to develop a neutralizing monoclonal antibody against human CTGF. We also investigated the neutralizing effect of the antibodies in our animal model. Firstly, by using the DNA immunization method, we developed a panel of anti‐CTGF antibodies recognizing the native conformation of human CTGF. Next, to examine the anti‐fibrosing effects of these antibodies, newborn B6 mice received subcutaneous injections of TGF‐β for 3 days with either anti‐CTGF neutralizing antibodies or control purified immunoglobulin. Anti‐CTGF antibodies significantly reduced skin fibrosis and collagen contents compared with the control group. These results suggest that our anti‐CTGF antibodies are capable of blocking the development of skin fibrosis at least partially and these anti‐CTGF neutralizing antibodies may be useful as the feasible strategy to treat skin fibrotic diseases as SSc. J. Cell. Physiol. 216: 680–687, 2008, © 2008 Wiley‐Liss, Inc.
Cancer stem cells in prostate adenocarcinoma: a target for new anticancer strategies
Authors: Fioriti D. , Mischitelli M. , Monaco F. Di , Silverio F. Di , Petrangeli E. , Russo G. , Giordano A. , Pietropaolo V. 
Published: May 2008

AbstractProstate cancer (PC) is major common malignancy in males in most industrialized Western countries, where it is the most commonly diagnosed cancer affecting men after middle age (>50 years). Over 90% of PC patients with incurable disease respond to primary treatment, which consists of intervention to lower serum testosterone. However, the duration of response is short (12–33 months) and in almost all patients, is followed by the emergence of a phenotype resistant to androgen deprivation in therapy (known as hormone or androgen‐resistant PC). Considerable research efforts have been directed towards the identification of markers associated with the initiation and progression of PC, yet there is little consensus about the target cell within prostate epithelium that is susceptible to malignant transformation. Stem cells may represent a major target for mutations leading to cancer as their longevity assures continued presence during the long latency between carcinogenic agents exposure and cancer development. Therefore in order to allow the development of more effective treatment strategies for PC, a better understanding of the molecular changes that underlie cancer stem cells is required. J. Cell. Physiol. 216: 571–575, 2008, © 2008 Wiley‐Liss, Inc.
Estradiol, a key endocrine signal in the sexual differentiation and activation of reproductive behavior in quail
Authors: Balthazart Jacques , Cornil Charlotte A. , Charlier Thierry D. , Taziaux Mélanie , Ball Gregory F. 
Published: May 2008

AbstractIn Japanese quail, estrogen's effects on sexual behavior can be divided into three classes based on the underlying mechanisms and time‐course of action and release. During embryonic life, the embryonic ovary secretes large amounts of estrogens. In contrast to what is observed in mammals where sexual differentiation essentially proceeds via masculinization of the males, in quail, females are demasculinized by their endogenous ovarian estrogens, an effect that can be blocked by injection of an aromatase inhibitor and mimicked in male embryos by an injection of estradiol. In adulthood, testosterone secreted by the testes is converted into estrogens by the preoptic aromatase. Locally produced estrogens activate male sexual behavior largely through the activation of estrogen receptors resulting in the transcription of a variety of genes, including brain aromatase (genomic effect). Both changes in estrogen production and action are observed within latencies ranging from a few hours to a few days, and are completely reversible. Additionally, brain aromatase activity can be modulated within minutes by calcium‐dependent phosphorylations, triggered by variations in glutamatergic neurotransmission. These rapid changes in aromatase activity affect with relatively short latencies (10–15 min) the expression of male sexual behavior in quail and also in mice. Overall, the effects of estrogens on sexual behavior can thus be categorized into three classes: organizational (irreversible genomic action during ontogeny), activational (reversible genomic action during adulthood) and rapid nongenomic effects. Rapid and slower changes in brain aromatase activity match well with the two modes of estrogen action on behavior and provide temporal variations in the estrogens' bioavailability that should be able to support the entire range of established effects for this steroid. J. Exp. Zool. 311A:323–345, 2009. © 2008 Wiley‐Liss, Inc.
Evolution of the placenta and associated reproductive characters in bats
Authors: Carter Anthony M. , Mess Andrea 
Published: May 2008

AbstractRecent advances in molecular phylogenetics indicate that the order Chiroptera is monophyletic and that one of four lineages of microbats (Rhinolophoidea) shares a common origin with megabats. Against this background we undertook a comprehensive analysis of placental evolution in bats. We defined a range of characters and character states associated with female reproduction, early development, placentation and the neonate. These were then mapped on a pre‐existing hypothesis of bat relationships that represents the current view from molecular studies. Our purpose was threefold. First, on the assumption of bat monophyly, we wished to establish the stem species pattern of extant chiropterans. Secondly, we asked whether there are derived character conditions in support of a common origin for Rhinolophoidea and the megabats. Thirdly, we looked for evolutionary character transformations that characterize higher‐level clades within Chiroptera, i.e. the megabats and the four lineages of microbats. The character condition occurring in the last common ancestor of Chiroptera was unequivocal for 21 of the 25 characters included in the analysis. The data did not offer support for a megabat‐rhinolophoid clade or the implication that microbats are paraphyletic. However, analysis of early development, placentation and other reproductive parameters resulted in derived character conditions for the megabats as well as for each of the four major lineages of microbats. J. Exp. Zool. (Mol. Dev. Evol.) 310B:428–449, 2008. © 2008 Wiley‐Liss, Inc.
Electrospun Zein Fibers Using Glutaraldehyde as the Crosslinking Reagent: Effect of Time and Temperature
Authors: Selling Gordon W. , Woods Kristen Kruger , Sessa David , Biswas Atanu 
Published: May 2008

AbstractGlutaraldehyde was used as a crosslinking reagent to produce electrospun zein fibers with improved physical properties and solvent resistance. Using 8% glutaraldehyde, round and ribbon fibers were produced with diameters between 1 and 70 µm. All fibers readily dissolved in acetic acid. Heating the zein/glutaraldehyde fibers at temperatures from 80 to 180 °C for different times provided various degrees of insolubility to the fibers. A model was developed relating the extent of dissolution with the amount of glutaraldehyde used and the temperature/time at which the fiber was exposed. The fibers were found to be birefringent; upon heating, the amount of α‐helix in the fiber was reduced.magnified image
Carbanions on Tap – Living Anionic Polymerization in a Microstructured Reactor
Authors: Wurm Frederik , Wilms Daniel , Klos Johannes , Löwe Holger , Frey Holger 
Published: May 2008

AbstractThe paper describes the living anionic polymerization of styrenes to homo‐ and diblock copolymers in continuous flow, using a microstructured mixing set‐up (“microreactor”). Reaction times and experimental effort are significantly reduced compared to classical batch methods that often require stringent reaction conditions and strict drying of the apparatus by “break‐seal” and “high vacuum” techniques. In continuous flow, residual impurities can be removed by purging the reactor with monomer and initiator solution before polymer samples are collected at the device outlet on a scale of up to 200 g · h−1. Facile molecular weight adjustment is achieved by variation of the flow rates of initiator or monomer solutions. The polymerization of styrene in THF and cyclohexane was studied with respect to control of molecular weight and polydispersity. Furthermore, diblock copolymers with different block lengths and low polydispersities, consisting of styrene‐ and 4‐tert‐butoxystyrene blocks were synthesized, employing a second micromixer for a delayed introduction of the additional monomer. All materials were investigated by NMR‐spectroscopy, SEC/MALLS, and MALDI‐TOF mass spectrometry, confirming narrow molecular weight distributions (MWDs; $\overline M _{\rm w} /\overline M _{\rm n}$ 1.09–1.25), molecular weights in the range of 500–70 000 g · mol−1, and complete end‐functionalization. No dimerization due to side reactions that would occur in the presence of oxygen was observed, evidencing efficient shielding of the apparatus from environmental influences.magnified image
Electrospray Deposition of Photoresist: A Low Impact Method for the Fabrication of Multilayered Films
Authors: Rietveld Ivo B. , Suganuma Naotoshi , Kobayashi Kei , Yamada Hirofumi , Matsushige Kazumi 
Published: May 2008

AbstractElectrospray deposition has been investigated as a substitute for photoresist spin coating. The morphology of Microposit S1813 photoresist films has been studied as a function of several spray conditions including resist concentration, substrate surface, and flow rate. Film morphology is controlled by three process parameters: the surface energy determines the equilibrium conditions of resist on the substrate; the viscosity and volume flux determine the relaxation time for the depositing resist solution after impact on the substrate. Electrosprayed photoresist films have been used for photolithographic patterning and it has been demonstrated that electrospray deposition is an effective method for deposition of photoresist on top of fragile, thin films, which can be used for multilayered thin film fabrication.magnified image
Self‐Assembling of SBS Block Copolymers as Templates for Conductive Silver Nanocomposites
Authors: Peponi Laura , Tercjak Agnieszka , Gutierrez Junkal , Stadler Hartmut , Torre Luigi , Kenny Josè M. , Mondragon Iñaki 
Published: May 2008

AbstractNovel nanocomposites based on conductive Ag nanoparticles and a self‐assembled polystyrene‐block‐polybutadiene‐block‐polystyrene (SBS) block copolymer were investigated. Good confinement of the nanoparticles into polystyrene microphase was achieved by the addition of DT as surfactant. The polymeric matrix kept its hexagonal order packed cylindrical structure up to 7 wt.‐% content of Ag nanoparticles. An electrostatic force microscopy (EFM) analysis of well‐dispersed metal‐organic hybrid Ag/SBS films was used to characterize the electric behavior of the conductive nanocomposites.magnified image