bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Advances and Future Prospects in Peptaibiotics, Hydrophobin, and Mycotoxin Research, and Their Importance for Chemotaxonomy of Trichoderma and Hypocrea
Authors: Degenkolb Thomas , von Döhren Hans , Fog Nielsen Kristian , Samuels Gary J. , Brückner Hans
Published: May 2008

Fungi of the genus Trichoderma with teleomorphs in Hypocrea are abundant producers of a group of amphiphilic, non‐ribosomal peptide antibiotics, which are rich in the non‐proteinogenic amino acid Aib (α‐aminoisobutyric acid). They are referred to as peptaibiotics, or peptaibols, if a 1,2‐amino alcohol is present at the C‐terminus. Trichoderma/Hypocrea, like other ascomycetous fungi, also produce hydrophobins, a class of small, cysteine‐rich proteins. Advanced soft ionization mass spectrometric techniques such as LC‐CID‐MS, LC‐ESI‐MSn, and IC‐MALDI‐TOF‐MS enabled the high‐throughput analysis, simultaneous detection and sequence determination of peptaibiotics and hydrophobins from minute quantities of fungal materials. Some Trichoderma species have been recognized to produce peptaibiotics as well as simple mycotoxins of the trichothecene group. The combination of sequence data of both groups of peptides with the pattern of low‐molecular‐weight secondary metabolites, including trichothecene‐type mycotoxins, independently confirmed the results of morphological, molecular, and phylogenetic analyses. This approach established a new lineage in Trichoderma/Hypocrea, the Brevicompactum clade, comprising four new and one redescribed species. Notably, commercial preparations of single or mixed cultures of Trichoderma species, in particular T. harzianum, and T. koningii, are registered as biocontrol agents for soil and plant pathogens. In this context, it is emphasized that the four mycotoxin‐producing species of the recently established Brevicompactum clade (T. brevicompactum, T. arundinaceum, T. turrialbense, and T. protrudens) are not closely related to any of the Trichoderma species currently used as biocontrol agents. Furthermore, possible health concerns about release of peptaibiotics in the biosphere are discussed with respect to their bioactivities and their use as drugs in human and veterinary medicine. Finally, future prospects regarding novel bioactivities and further research needs, including interdisciplinary taxonomic approaches, are outlined.
Natural Cyclopeptaibiotics and Related Cyclic Tetrapeptides: Structural Diversity and Future Prospects
Authors: Degenkolb Thomas , Gams Walter , Brückner Hans
Published: May 2008

Linearity is not considered a prerequisite anymore, and extension of the current definition of ‘peptaibiotics’ to cyclic, Aib‐containing peptides is proposed. Sequences and bioactivities, together with ecophysiological importance of cyclopeptaibiotics and related cyclic tetrapeptides, and their fungal‐taxonomic relationships, are discussed.
Comparative Study of Cyperus rotundus Essential Oil by a Modified GC/MS Analysis Method. Evaluation of Its Antioxidant, Cytotoxic, and Apoptotic Effects
Authors: Kilani Soumaya , Ledauphin Jérôme , Bouhlel Ines , Sghaier Mohamed Ben , Boubaker Jihed , Skandrani Inès , Mosrati Ridha , Ghedira Kamel , Barillier Daniel , Chekir‐Ghedira Leila
Published: May 2008

Gas chromatography coupled with mass spectrometry (GC/MS), using both electron impact (EI) and chemical ionization (CI) detection modes on apolar and polar stationary phases, led to the determination of the volatile composition of the essential oil obtained from tubers of Cyperus rotundus (Cyperaceae). In this study, more than 33 compounds were identified and then compared with the results obtained in our previous work. Cyperene, α‐cyperone, isolongifolen‐5‐one, rotundene, and cyperorotundene were the principal compounds comprising 62% of the oil. An in vitro cytotoxicity assay with MTT indicated that this oil was very effective against L1210 leukaemia cells line. This result correlates with significantly increased apoptotic DNA fragmentation. The oxidative effects of the essential oil were evaluated using the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), xanthine/xanthine oxidase assays, and the scavenging of superoxide radical assay generated by photo‐reduction of riboflavin. The antimutagenic activity of essential oil has been examined by following the inhibition of H2O2 UV photolysis which induced strand‐break formation in pBS plasmid DNA scission assay. Based on all these results, it is concluded that C. rotundus essential‐oil composition established by GC/MS analysis, in EI‐ and CI‐MS modes, presents a variety of a chemical composition we were not able to detect with only GC/MS analysis in our previous work. This essential oil exhibited antioxidant, cytotoxic, and apoptotic properties.
Bioactive Marine Prostanoids from Octocoral Clavularia viridis
Authors: Lin Yun‐Sheng , Taha Khalil Ashraf , Chiou Shih‐Hwa , Kuo Yuh‐Chi , Cheng Yuan‐Bin , Liaw Chia‐Ching , Shen Ya‐Ching
Published: May 2008

Chemical investigation of the nonpolar extract of soft coral Clavularia viridis resulted in isolation of five new prostanoids, designated as claviridic acids A–E (1–5, resp.), in addition to the known clavulones I–III. Their structures were determined on the basis of spectroscopic techniques, especially HR‐ESI‐MS, CD, and 2D‐NMR experiments. The isolated marine prostanoids exhibited potent inhibitory effect on PHA‐induced proliferation of peripheral blood mononuclear cells (PBMC), as well as significant cytotoxic activity against human gastric cancer cells (AGS).
Preparation and Recognition Study on the Peptides in Aqueous Media of Poly(pyridine derivative‐co‐acrylamide)
Authors: ZHAO Jian‐Xin , QIAO Yi‐Tao , FENG Jing , YUAN Zhi
Published: May 2008

Three copolymers (bearing metal ion coordinated sites) P1, P2 and P3 were synthesized and their recognition behavior on predetermined peptide sequences was studied by isothermal titration calorimetry.
Identification of four Engrailed genes in the Japanese lamprey, Lethenteron japonicum
Authors: Matsuura Manami , Nishihara Hidenori , Onimaru Koh , Kokubo Nobuhiro , Kuraku Shigehiro , Kusakabe Rie , Okada Norihiro , Kuratani Shigeru , Tanaka Mikiko
Published: May 2008

We have isolated four homologs of Engrailed genes from the Japanese lamprey, Lethenteron japonicum, an agnathan that occupies a critical phylogenic position between cephalochordates and gnathostomes. We named these four genes LjEngrailedA, LjEngrailedB, LjEngrailedC, and LjEngrailedD. LjEngrailedA, LjEngrailedB, and LjEngrailedD share a major expression domain in the presumptive midbrain–hindbrain boundary region of the central nervous system, although their levels and timing of expression differed. On the other hand, LjEngrailedC transcripts were in the pharyngeal ectoderm and the ventral ectoderm of the body wall. In addition, LjEngrailedA was expressed in the ventral side of the epibranchial muscle precursors. LjEngrailedD transcripts were seen in the mesodermal cells of the mandibular arch and later in a group of cells responsible for the formation of the upper lip, lower lip, and velum. Our results provide clues to the evolution of these structures as well as a possible scenario for duplication events of Engrailed genes. Developmental Dynamics 237:1581–1589, 2008. © 2008 Wiley‐Liss, Inc.
Adiponectin and adiponectin receptor genes are coexpressed during zebrafish embryogenesis and regulated by food deprivation
Authors: Nishio Shin‐Ichi , Gibert Yann , Bernard Laure , Brunet Frédéric , Triqueneaux Gérard , Laudet Vincent
Published: May 2008

Adiponectin is an adipocytokine that plays important roles in glucose and lipid homeostasis. Adiponectin binds to two types of transmembrane receptors: Adiponectin receptor (AdipoR) type 1 and 2. We isolated and characterized the two adiponectin genes (adiponectin A and B) and the three adiponectin receptors in zebrafish. In adult, adiponectin A is only detected in the kidney while adiponectin B mRNAs are widely expressed and are detected in the liver, adipose tissue, muscle, and brain. The receptors are found in many tissues such as the brain, gut, liver, adipose tissue, kidney, and ovary. Interestingly, we detect embryonic synexpression of all genes in the pharyngeal region. We observed that adiponectin B expression in adult liver is reduced while the expression of the receptors is increased in fasted fish. These data indicate that the upstream members of the Adiponectin pathway have complex expression patterns and are regulated by food deprivation in zebrafish. Developmental Dynamics 237:1682–1690, 2008. © 2008 Wiley‐Liss, Inc.
What's left in asymmetry?
Authors: Aw Sherry , Levin Michael
Published: May 2008

Left–right patterning is a fascinating problem of morphogenesis, linking evolutionary and cellular signaling mechanisms across many levels of organization. In the past 15 years, enormous progress has been made in elucidating the molecular details of this process in embryos of several model species. While many outside the field seem to believe that the fundamental aspects of this pathway are now solved, workers on asymmetry are faced with considerable uncertainties over the details of specific mechanisms, a lack of conceptual unity of mechanisms across phyla, and important questions that are not being pursued in any of the popular model systems. Here, we suggest that data from clinical syndromes, cryptic asymmetries, and bilateral gynandromorphs, while not figuring prominently in the mainstream work on LR asymmetry, point to crucial and fundamental gaps of knowledge about asymmetry. We identify 12 big questions that provide exciting opportunities for fundamental new advances in this field. Developmental Dynamics 237:3453–3463, 2008. © 2008 Wiley‐Liss, Inc.
Expression and function of BMP3 during chick limb development
Authors: Gamer Laura W. , Ho Victoria , Cox Karen , Rosen Vicki
Published: May 2008

Bone morphogenetic proteins (BMPs) play diverse roles in many aspects of skeletal development and bone homeostasis. During endochondral ossification, tight regulation of BMP activity is required to assure proper survival, proliferation and differentiation of skeletal progenitor cells into chondrocytes and osteoblasts. BMP3, a structurally divergent member of the BMP family, acts as a negative regulator of bone formation by limiting BMP signal transduction. In this study, we focus on the chick limb where we find BMP3 has a unique localization pattern with strong expression in the developing perichondrium. Overexpression of BMP3 in chick wing bud at the onset of chondrogenesis, using replication competent retrovirus, reduces BMP signaling leading to increased cell proliferation and delayed cell differentiation, resulting in expanded skeletal elements and joint fusions. Our results suggest that BMP3 expression in the perichondrium may serve to regulate cartilage cell proliferation by modulating the levels of BMP signaling, thus ensuring proper endochondral ossification. Developmental Dynamics 237:1691–1698, 2008. © 2008 Wiley‐Liss, Inc.
Cardiac expression patterns of endothelin‐converting enzyme (ECE): Implications for conduction system development
Authors: Sedmera David , Harris Brett S. , Grant Elizabeth , Zhang Ning , Jourdan Jane , Kurkova Dana , Gourdie Robert G.
Published: May 2008

The spatiotemporal distribution of the endothelin‐converting enzyme (ECE) protein in the embryonic chick heart and the association of this polypeptide with the developing cardiac conduction system is described here for the first time. Further, we show how cardiac hemodynamic load directly affects ECE level and distribution. Endothelin (ET) is a cytokine involved in the inductive recruitment of Purkinje fibers. ET is produced by proteolytic cleavage of Big‐ET by ECE. We generated an antibody against chick ECE recognizing a single band at ∼70 kD to correlate the cardiac expression of this protein with that reported previously for its mRNA. ECE protein expression was more widespread compared to its mRNA, being present in endothelial cells, mesenchymal cells, and myocytes, and particularly enriched in the trabeculae and nascent ventricular conduction system. The myocardial expression was significantly modified under experimentally altered hemodynamic loading. In vivo, ET receptor blockade with bosentan delayed activation sequence maturation. These data support a role for ECE in avian cardiac conduction system differentiation and maturation. Developmental Dynamics 237:1746–1753, 2008. © 2008 Wiley‐Liss, Inc.
IL‐2 induces in vivo suppression by CD4+CD25+Foxp3+ regulatory T cells
Authors: Brandenburg Susan , Takahashi Takeshi , de la Rosa Maurus , Janke Marko , Karsten Gabriele , Muzzulini Till , Orinska Zane , Bulfone‐Paus Silvia , Scheffold Alexander
Published: May 2008

Interleukin‐2 (IL‐2) treatment is currently used to enhance T cell‐mediated immune responses against tumors or in viral infections. At the same time, IL‐2 is essential for the peripheral homeostasis of CD4+CD25+Foxp3+ regulatory T cells (Treg). In our study, we show that IL‐2 is also an important activator of Treg suppressive activity in vivo. IL‐2 treatment induces Treg expansion as well as IL‐10 production and increases their suppressive potential in vitro. Importantly, in vivo application of IL‐2 via gene‐gun vaccination using IL‐2 encoding DNA plasmids (pIL‐2) inhibited naive antigen‐specific T cell proliferation as well as a Th1‐induced delayed type hypersensitivity response. The suppressive effect can be transferred onto naive animals by Treg from IL‐2‐treated mice and the suppression depends on the synergistic action of IL‐10 and TGF‐β. These data highlight that during therapeutic treatment with IL‐2 the concomitant activation of Treg may indeed counteract the intended activation of cellular immunity.
Human CD4+ T cells maintain specific functions even under conditions of extremely restricted ATP production
Authors: Tripmacher Robert , Gaber Timo , Dziurla René , Häupl Thomas , Erekul Kerem , Grützkau Andreas , Tschirschmann Miriam , Scheffold Alexander , Radbruch Andreas , Burmester Gerd‐Rüdiger , Buttgereit Frank
Published: May 2008

We investigated the energy‐adaptive potential of human CD4+ T cells under conditions of impaired oxidative phosphorylation (OXPHOS) and/or low glucose (inhibiting glycolysis). These cells often encounter these conditions when executing their functions in injured/inflamed tissues, even though T cells themselves require constant and adequate energy supply via ATP. We assessed two specific functions, cytokine synthesis and proliferation, and addressed whether adaptive characteristics also emerged in vivo. In glucose‐containing medium, both cytokine production and proliferation were unaffected, even under complete OXPHOS suppression. Only when glucose was also absent were these functions significantly decreased. Partial recovery of OXPHOS and induced glycolysis were crucial for the maintenance of cellular energy supply. Adaptive regulatory mechanisms are clinically relevant because hypoxia up‐regulates glycolytic genes but down‐regulates OXPHOS genes in vivo. Our data demonstrate an unexpectedly high, clinically relevant adaptive potential of human CD4+ T cells to maintain specific functions even under severely impaired bioenergetic conditions.

Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/200838047_s.pdf
IFN‐γ activation of mesenchymal stem cells for treatment and prevention of graft versus host disease
Authors: Polchert David , Sobinsky Justin , Douglas GW , Kidd Martha , Moadsiri Ada , Reina Eduardo , Genrich Kristyn , Mehrotra Swati , Setty Suman , Smith Brett , Bartholomew Amelia
Published: May 2008

Graft versus host disease (GVHD), mediated by donor T cells, is a significant source of morbidity and mortality following allogeneic stem cell transplantation. Mesenchymal stem cells (MSC) can successfully treat ongoing graft versus host disease, presumably due to their ability to suppress donor T cell proliferation. Little is known about the potential of MSC to prevent GVHD. Here we show that bone marrow‐isolated MSC can suppress the development of GVHD if given after donor T cell recognition of antigen. IFN‐γ was required to initiate MSC efficacy. Recipients of IFN‐γ–/– T cells did not respond to MSC treatment and succumbed to GVHD. MSC, pre‐treated with IFN‐γ, became immediately active and could suppress GVHD more efficiently than a fivefold‐greater number of MSC that were not activated. When given at the time of bone marrow transplantation, activated MSC could prevent GVHD mortality (100% survival, p=0.006). MSC activation was dependent on the magnitude of IFN‐γ exposure, with increased IFN‐γ exposure leading to increased MSC suppression of GVHD. Activated MSC present a new strategy for preventing GVHD using fewer MSC.

See accompanying commentary: http://dx.doi.org/10.1002/eji.200838433
Bacillus anthracis spores and lethal toxin induce IL‐1β via functionally distinct signaling pathways
Authors: Kang Tae Jin , Basu Subhendu , Zhang Lei , Thomas Karen E. , Vogel Stefanie N. , Baillie Les , Cross Alan S.
Published: May 2008

Previous reports suggested that lethal toxin (LT)‐induced caspase‐1 activity and/or IL‐1β accounted for Bacillus anthracis (BA) infection lethality. In contrast, we now report that caspase‐1‐mediated IL‐1β expression in response to BA spores is required for anti‐BA host defenses. Caspase‐1–/– and IL‐1β–/– mice are more susceptible than wild‐type (WT) mice to lethal BA infection, are less able to kill BA both in vivo and in vitro, and addition of rIL‐1β to macrophages from these mice restored killing in vitro. Non‐germinating BA spores induced caspase‐1 activity, IL‐1β and nitric oxide, by which BA are killed in WT but not in caspase‐1–/– mice, suggesting that the spore itself stimulated inflammatory responses. While spores induced IL‐1β in LT‐susceptible and ‐resistant macrophages, LT induced IL‐1β only in LT‐susceptible macrophages. Cooperation between MyD88‐dependent and ‐independent signaling pathways was required for spore‐induced, but not LT‐induced, IL‐1β. While both spores and LT induced caspase‐1 activity and IL‐1β, LT did not induce IL‐1β mRNA, and spores did not induce cell death. Thus different components of the same bacterium each induce IL‐1β by distinct signaling pathways. Whereas the spore‐induced IL‐1β limits BA infection, LT‐induced IL‐1β enables BA to escape host defenses.

Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/2008/38141_s.pdf
Cover Picture: Mast cell regulation of epithelial TSLP expression plays an important role in the development of allergic rhinitis – Eur. J. Immunol. 6/2008
Authors: Miyata Masanori , Hatsushika Kyosuke , Ando Takashi , Shimokawa Naomi , Ohnuma Yuko , Katoh Ryohei , Suto Hajime , Ogawa Hideoki , Masuyama Keisuke , Nakao Atsuhito
Published: May 2008

The cover shows thymic stromal lymphopoietin (TSLP) expression in the nasal epithelium in an OVA‐based murine model of allergic rhinitis. This image was taken from the article by Miyata pp.

1487–1492

, et al. (pp. 1487–1492), in which the authors demonstrate that mast cells are critical regulators of allergic rhinitis development through regulation of TSLP expression, possibly mediated via FcεRI.
Metal Halide/N‐Donor Organic Ligand Hybrid Materials with Confined Energy Gaps and Emissions
Authors: Wang Wei , Qiao Juan , Dong Guifang , Wang Liduo , Duan Lian , Zhang Deqiang , Qiu Yong
Published: May 2008

Four group 12 metal halide/N‐donor organic ligand hybrid materials, ZnCl2(AEC)2 (1), ZnI2(AEC)2 (2), CdI2(AEC)2 (3), and HgI2(AEC)2 (4) [AEC=N‐(2‐aminoethyl)carbazole] were synthesized and characterized. Single crystals of ZnCl2(AEC)2·CH3CN (1·CH3CN) and ZnI2(AEC)2·CH3CN (2·CH3CN) were obtained from solutions. Single‐crystal X‐ray diffraction analysis revealed that 1·CH3CN and 2·CH3CN form quasi‐1D structures of (ZnCl2)n and (ZnI2)n chains. The two AEC ligands in one hybrid molecule are dissymmetric due to the steric hindrance effect of the AEC moiety and the hydrogen bonding of the CH3CN guest molecules. The UV/Vis spectra of compounds 1–4 were measured, and the optical energy gaps (Eg) of compounds 1–3 are very close to that of AEC; the value of Eg for compound 4 is a little smaller. Steady and transient photoluminescence studies revealed that the emissions of compounds 1–3 are attributed to the AEC ligands, whereas compound 4 does not emit light owing to the heavy‐atom effect. Theoretical studies of the electronic structures confirmed that the optical energy gaps and emissions of the hybrid materials are almost confined by the AEC organic ligand rather than the metal halides.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The Fabrication and Magnetic Properties of Ni Fibers Synthesized Under External Magnetic Fields
Authors: Gong Chunhong , Yu Laigui , Duan Yuping , Tian Juntao , Wu Zhishen , Zhang Zhijun
Published: May 2008

One‐dimensional (1D) nanocrystallites Ni fibers with different lengths were fabricated by the reduction of Ni2+ ions by hydrazine hydrate in the presence of external magnetic fields. The effect of the reaction conditions and magnetic field intensity on the microstructures and magnetic properties of the Ni fibers were systematically investigated by scanning electron microscopy (SEM), X‐ray diffraction (XRD), and measurement of hysteresis loops at room temperature. It was found that both the intensity of the external magnetic field and the concentration of the nickel salt solution played key roles in governing the microstructures and magnetic properties of the Ni fibers. Namely, the mean length of the Ni fibers increased markedly with increasing Ni2+ ion concentration and intensity of the external magnetic field as well. Moreover, the Ni fiber samples prepared under external magnetic fields had higher squareness and coercivity values than those synthesized in the absence of the external magnetic field. Therefore, a relatively high intensity of the external magnetic field and concentration of the Ni2+ ions was selected for the preparation of the desired Ni fibers with improved microstructures and magnetic properties. The present approach has the advantages of having a fast reaction rate and low cost and might be promising for the effective control of the shape and magnetic properties of magnetic materials and for large‐scale production as well. The resulting Ni fibers might be potential catalysts, magnetic storage materials, and conductive fillers for shielding of electromagnetic interference (EMI). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Straightforward Synthesis of Fluorinated Amphiphilic Thiols
Authors: Gentilini Cristina , Boccalon Mariangela , Pasquato Lucia
Published: May 2008

C8‐perfluoroalkyl thiols bearing a polyoxyethylene chain of variable length were prepared in good yields following a straightforward synthetic strategy. These thiols are soluble in organic solvents of different polarities from chloroform to methanol. The thiol with a PEG550 chain shows very good solubility in water. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of 1‐Silabicyclo[4.4.0]dec‐5‐en‐4‐ones: A Model of the A and B Rings of 10‐Silatestosterone
Authors: Díez‐González Silvia , Paugam Renée , Blanco Luis
Published: May 2008

1‐Silabicyclo[4.4.0]dec‐5‐en‐4‐ones, a novel type of organosilicon compound, have been prepared from 2‐methylidene‐1‐(3‐oxopropyl)‐1‐silacyclohexanes by an ene reaction as the key transformation. Various routes to the starting aldehydes from 3‐halopropyl, allyl, or 3‐(4‐methoxybenzyloxy)propylsilanes have been investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Intermolecular Hydrogen‐Bonding Pattern of a Glycosyl Donor: The Key to Understanding the Outcome of Sialylation
Authors: Kononov Leonid O. , Malysheva Nelly N. , Kononova Elena G. , Orlova Anna V.
Published: May 2008

Changes in the hydrogen‐bonding pattern in solutions of glycosyl donor induced by the addition of external amides/imides or by concentration changes influence the yield and stereoselectivity of sialylation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Predicting mating flights through meteorological cues using multi‐scale logistic regression
Authors: Kim MyungSuk , Lim Johan , Wang Suojin
Published: May 2008

The red imported fire ant is one of the most destructive animals in the US. Its prolific ability through mating flights has aggravated the situation. Understanding the environmental cues triggering mating flights would be important for a comprehensive control solution. Fire ant colony activities related to mating flights were daily monitored from April 2001 to March 2002, and the associated weather data were documented. The method of logistic regression is used to identify environmental factors associated with mating flight where multi‐scale decomposition of the meteorological variables is considered to identify the within and the between cues for mating flights. Our empirical results indicate that ambient temperature, relative humidity, wind speed, barometric pressure, and recent rain are significant factors that trigger or influence fire ant mating flights. Among those factors, the ambient temperature, the change in barometric pressure, relative humidity, wind speed, and recent rain are found to be the macro‐scale cues, whereas the ambient temperature is also found to be the micro‐scale cues. Copyright © 2008 John Wiley & Sons, Ltd.
Special issue on biofluid dynamics
Authors: Nithiarasu P.
Published: May 2008

A total of 10 papers in the area of computational biofluid dynamics are collated and presented in this special issue. Copyright © 2008 John Wiley & Sons, Ltd.
Running increases neurogenesis without retinoic acid receptor activation in the adult mouse dentate gyrus
Authors: Åberg Elin , Perlmann Thomas , Olson Lars , Brené Stefan
Published: May 2008

Both vitamin A deficiency and high doses of retinoids can result in learning and memory impairments, depression as well as decreases in cell proliferation, neurogenesis and cell survival. Physical activity enhances hippocampal neurogenesis and can also exert an antidepressant effect. Here we elucidate a putative link between running, retinoid signaling, and neurogenesis in hippocampus. Adult transgenic reporter mice designed to detect ligand‐activated retinoic acid receptors (RAR) or retinoid X receptors (RXR) were used to localize the distribution of activated RAR or RXR at the single‐cell level in the brain. Two months of voluntary wheel‐running induced an increase in hippocampal neurogenesis as indicated by an almost two‐fold increase in doublecortin‐immunoreactive cells. Running activity was correlated with neurogenesis. Under basal conditions a distinct pattern of RAR‐activated cells was detected in the granule cell layer of the dentate gyrus (DG), thalamus, and cerebral cortex layers 3–4 and to a lesser extent in hippocampal pyramidal cell layers CA1–CA3. Running did not change the number of RAR‐activated cells in the DG. There was no correlation between running and RAR activation or between RAR activation and neurogenesis in the DG of hippocampus. Only a few scattered activated retinoid X receptors were found in the DG under basal conditions and after wheel‐running, but RXR was detected in other areas such as in the hilus region of hippocampus and in layer VI of cortex cerebri. RAR agonists affect mood in humans and reduce neurogenesis, learning and memory in animal models. In our study, long‐term running increased neurogenesis but did not alter RAR ligand activation in the DG in individually housed mice. Thus, our data suggest that the effects of exercise on neurogenesis and other plasticity changes in the hippocampal formation are mediated by mechanisms that do not involve retinoid receptor activation. © 2008 Wiley‐Liss, Inc.
PLC‐β1 knockout mice as a model of disrupted cortical development and plasticity: Behavioral endophenotypes and dysregulation of RGS4 gene expression
Authors: McOmish Caitlin E. , Burrows Emma L. , Howard Monique , Hannan Anthony J.
Published: May 2008

The complexity of the genetics underlying schizophrenia is highlighted by the multitude of molecular pathways that have been reported to be disrupted in the disorder including muscarinic, serotonergic, and glutamatergic signaling systems. It is of interest, therefore, that phospholipase C‐β1 (PLC‐β1) acts as a point of convergence for these pathways during cortical development and plasticity. These signaling pathways, furthermore, are susceptible to modulation by RGS4, one of the more promising candidate genes for schizophrenia. PLC‐β1 knockout mice were behaviorally assessed on tests including fear conditioning, elevated plus maze, and the Y maze. In situ hybridization was used to assess RGS4 expression. We found that PLC‐β1 knockout mice display abnormal anxiety profiles on some, but not all measures assessed, including decreased anxiety on the elevated plus maze. We also show memory impairment and a complete absence of acquisition of hippocampal‐dependent fear conditioning. Furthermore, at a molecular level, we demonstrate dramatic changes in expression of RGS4 mRNA in selective regions of the PLC‐β1 knockout mouse brain, particularly the CA1 region of the hippocampus. These results validate the utility of the PLC‐β1 knockout mouse as a model of schizophrenia, including molecular and cellular evidence for disrupted cortical maturation and associated behavioral endophenotypes. © 2008 Wiley‐Liss, Inc.
Propagation of specific network patterns through the mouse hippocampus
Authors: Both Martin , Bähner Florian , von Bohlen und Halbach Oliver , Draguhn Andreas
Published: May 2008

Network oscillations bind neurons into transient assemblies with coherent activity, enabling temporal coding. In the mammalian hippocampus, spatial relationships are represented by sequences of action potentials of place cells. Such patterns are established during memory acquisition and are re‐played during sharp wave‐ripple complexes in CA1 in subsequent sleep episodes. These events originate in CA3 and travel towards CA1 and downstream cortical areas. It is unclear, however, whether specific sequences of ripple‐associated firing are solely defined within the CA1 network or whether these patterns are directly entrained by preceding activities of neurons within CA3. Using a model of sharp wave‐ripple oscillations (SPW‐R) in mouse hippocampal slices we analyzed the propagation of these signals between CA3 and CA1. We found tight coupling between high‐frequency network activity in CA3 and CA1. Propagation of ripples through the hippocampal loop maintained precise temporal relationships at the network and cellular level, as indicated by coupling of field potentials, multiunit and single cell activity between major portions of CA3 and CA1. Moreover, SPW‐R‐like activity in CA1 could be elicited by electrical stimulation within area CA3 while antidromic activation of CA1 failed to induce organized high‐frequency oscillations. Our data show that the specificity of neuronal assemblies is maintained with cell‐to‐cell precision while SPW‐R propagate along the hippocampal loop. © 2008 Wiley‐Liss, Inc.
Status epilepticus during old age is not associated with enhanced hippocampal neurogenesis
Authors: Rao Muddanna S. , Hattiangady Bharathi , Shetty Ashok K.
Published: May 2008

Increased production of new neurons in the adult dentate gyrus (DG) by neural stem/progenitor cells (NSCs) following acute seizures or status epilepticus (SE) is a well known phenomenon. However, it is unknown whether NSCs in the aged DG have similar ability to upregulate neurogenesis in response to SE. We examined DG neurogenesis after the induction of continuous stages III‐V seizures (SE) for over 4 h in both young adult (5‐months old) and aged (24‐months old) F344 rats. The seizures were induced through 2–4 graded intraperitoneal injections of the excitotoxin kainic acid (KA). Newly born cells in the DG were labeled via daily intraperitoneal injections of the 5′‐bromodeoxyuridine (BrdU) for 12 days, which commenced shortly after the induction of SE in KA‐treated rats. New cells and neurons in the subgranular zone (SGZ) and the granule cell layer (GCL) were analyzed at 24 h after the last BrdU injection using BrdU and doublecortin (DCX) immunostaining, BrdU‐DCX and BrdU‐NeuN dual immunofluorescence and confocal microscopy, and stereological cell counting. Status epilepticus enhanced the numbers of newly born cells (BrdU+ cells) and neurons (DCX+ neurons) in young adult rats. In contrast, similar seizures in aged rats, though greatly increased the number of newly born cells in the SGZ/GCL, failed to increase neurogenesis due to a greatly declined neuronal fate‐choice decision of newly born cells. Only 9% of newly born cells in the SGZ/GCL differentiated into neurons in aged rats that underwent SE, in comparison to the 76% neuronal differentiation observed in age‐matched control rats. Moreover, the number of newly born cells that migrate abnormally into the dentate hilus (i.e., ectopic granule cells) after SE in the aged hippocampus is 92% less than that observed in the young adult hippocampus after similar SE. Thus, SE fails to increase the addition of new granule cells to the GCL in the aged DG, despite a considerable upregulation in the production of new cells, and SE during old age leads to much fewer ectopic granule cells. These results have clinical relevance because earlier studies have implied that both increased and abnormal neurogenesis occurring after SE in young animals contributes to chronic epilepsy development. © 2008 Wiley‐Liss, Inc.
Multiple signals of recognition memory in the medial temporal lobe
Authors: Yassa Michael A. , Stark Craig E.L.
Published: May 2008

The medial temporal lobe (MTL) is known to play an essential role in recognition memory (the ability to judge the prior occurrence of a stimulus). Electrophysiological studies in nonhuman primates have suggested the presence of more than one type of recognition signal in the medial temporal lobe (e.g., novelty, familiarity, and recency). It has also been suggested that the perirhinal cortex plays an essential role in visual recognition memory. Here, we present fMRI results from 16 college‐aged participants who underwent a continuous yes/no recognition task of novel and familiar pictures with multiple stimulus presentations. Our goal was to understand the dynamics of recognition in the MTL over multiple trials. We hypothesized that we could see changes in signal with repeated exposure that carry information related to novelty, familiarity, and recency. Whole brain activation maps demonstrated a strong novelty effect, marked by activity in several frontal and occipital regions that decreases with increasing number of presentations. The opposite pattern was observed in several other regions that include the supramarginal gyrus and inferior parietal lobule. In the MTL region, we observed monotonic decreases in activity across trials in the parahippocampal cortex as well as the anterior perirhinal cortex. We also observed monotonic increases in activity in the posterior perirhinal cortex with increasing memory strength. In addition, we observed clear effects of pre‐experimental familiarity with the stimulus in several regions. Consistent with previously reported electrophysiological data, we found evidence for several medial temporal lobe signals carrying recency, familiarity, and novelty information. © 2008 Wiley‐Liss, Inc.
Evaluating the differential roles of the dorsal dentate gyrus, dorsal CA3, and dorsal CA1 during a temporal ordering for spatial locations task
Authors: Hunsaker Michael R. , Kesner Raymond P.
Published: May 2008

It has been demonstrated that the dorsal CA1 subregion of the hippocampus mediates temporal processing of information, that dorsal CA3 participates in the spatiotemporal processing of memory, and the dorsal dentate gyrus (DG) mediates spatial pattern separation. A temporal ordering of spatial locations task was developed to test the role of the dorsal DG, CA3, and CA1 for the temporal processing of spatial information with either high or low levels of spatial interference. The results indicate that animals with DG lesions showed difficulty performing the task at high levels of spatial interference, but were able to perform the task well when there was low spatial interference. Animals with lesions to CA3 did not show a preference for either spatial location presented during the study phase during the preference test, suggesting impaired spatiotemporal processing. Animals with lesions to CA1 showed a preference for a later presented spatial location over the earlier, the opposite preference to that shown by control animals. © 2008 Wiley‐Liss, Inc.
Diazodiphenylmethane and Monosubstituted Butadienes: Kinetics and a New Chapter of Vinylcyclopropane Chemistry
Authors: Ohta Akihiro , Dahl Klaus , Raab Rainer , Geittner Jochen , Huisgen Rolf
Published: May 2008

Diazodiphenylmethane (DDM) undergoes cycloadditions to 1‐substituted buta‐1,3‐dienes exclusively at the C(3)C(4) bond. At room temperature, the N2 loss from the initially formed 4,5‐dihydro‐3H‐pyrazoles 2 is faster than the cycloaddition and furnishes the vinylcyclopropane derivatives 7 and 9 with structural retention at the C(1)C(2) bond. 2‐Substituted butadienes react with DDM at the C(3)C(4) bond to give 12; isoprene, however, affords 3,4/1,2 products in the ratio of 86 : 14. DDM is a nucleophilic 1,3‐dipole: 1‐Cyanobutadiene reacts 400 times faster than 1‐methoxybuta‐1,3‐diene (DMF, 40°). The log k2 for the additions to six 1‐substituted butadienes show a linear correlation with σp (Hammett) and ϱ=+2.9; the log k2 of five 2‐substituted butadienes are linearly related to Taft's σI (ϱ=+1.7). The structures of the vinylcyclopropanes 7, 9, and 12 are established by NMR spectra and oxidation. A cyclopropyl carbinyl cation is made responsible for the isomerization of 12, R=Ph, Me, by acetic acid to 4‐substituted 1,1‐diphenylpenta‐1,3‐dienes 25 and 29; TsOH at 200° converts 25 further to 9,10‐dihydro‐9‐methyl‐10‐phenyl‐9,10‐ethanoanthracene (27). Thermal rearrangement of 7, 9, and 12 at 200–300° produces the 3‐ or 1‐substituted 4,4‐diphenylcyclopentenes 30 and 31. These give the same mass spectra as the vinylcyclopropanes, and an open‐chain distonic radical cation is suggested as common intermediate. Besides spectroscopic evidence for the cyclopentene structures, hydrogenation and epoxidation are described; NMR data support the trans‐attack by perbenzoic acid.
Stability of Hoogsteen‐Type Triplexes – Electrostatic Attraction between Duplex Backbone and Triplex‐Forming Oligonucleotide (TFO) Using an Intercalating Conjugate
Authors: Globisch Daniel , Bomholt Niels , Filichev Vyacheslav V. , Pedersen Erik B.
Published: May 2008

Syntheses are described for two novel twisted intercalating nucleic acid (TINA) monomers where the intercalator comprises a benzene ring linked to a naphthalimide moiety via an ethynediyl bridge. The intercalators Y and Z have a 2‐(dimethylamino)ethyl and a methyl residue on the naphthalimide moiety, respectively. When used as triplex‐forming oligonucleotides (TFOs), the novel naphthalimide TINAs show extraordinary high thermal stability in Hoogsteen‐type triplexes and duplexes with high discrimination of mismatch strands. DNA Strands containing the intercalator Y show higher thermal triplex stability than DNA strands containing the intercalator Z. This observation can be explained by the ionic interaction of the protonated dimethylamino group under physiological conditions, targeting the negatively charged phosphate backbone of the duplex. This interaction leads to an extra binding mode between the TFO and the duplex, in agreement with molecular‐modeling studies. We believe that this is the first example of an intercalator linking the TFO to the phosphate backbone of the duplex by an ionic interaction, which is a promising tool to achieve a higher triplex stability.
Constituents from Leaves of Scolopia chinensis
Authors: Lu Ya‐Nan , Xie Guang‐Bo , Bi Dan , Shi Hai‐Ming , Tu Peng‐Fei
Published: May 2008

Two new phenolic glycosides, scolochinenosides A and B (1 and 2), and a new flavonoid glycoside, scoloside A (3), were isolated from the leaves of Scolopia chinensis (Lour.) Clos, together with eight known compounds. The structures of the new compounds were established on the basis of chemical and spectroscopic evidences.
Crystal Structure of Akuammigine Picrate Hydrate
Authors: Laus Gerhard , Wurst Klaus
Published: May 2008

The single‐crystal X‐ray data of akuammigine picrate hydrate (1⋅Picr⋅H2O) confirm the relative configuration of the indole alkaloid akuammigine (1) as epiallo (Fig. 1). With reference to the known (15S)‐configuration due to biosynthesis, the absolute configuration of the other stereogenic centers is thus given by (3R,19S,20S). Four crystallographically independent molecules are observed in the asymmetric unit (Fig. 2). Each of the alkaloid cations forms H‐bonds to a H2O and a picrate anion (Fig. 3). The H2O molecules are further associated by a H‐bond as indicated by the short O⋅⋅⋅O distance (Table 2). The conformation in the solid state of the picrate hydrate is now firmly established, and a cute H‐bonding motif is observed.
Yunnandaphninines F and G, New C30 Alkaloids from Daphniphyllum yunnanense
Authors: Di Ying‐Tong , Liu Ling‐Li , Li Chun‐Shun , Zhang Yu , Zhang Qiang , Mu Shu‐Zhen , Sun Qian‐Yun , Yang Fu‐Mei , Liu Hai‐Yang , Hao Xiao‐Jiang
Published: May 2008

Eight C30 Daphniphyllum alkaloids, including two new ones, yunnandaphninines F and G (1 and 2, resp.), were isolated from the leaves and stems of Daphniphyllum yunnanense. Their structures were elucidated on the basis of the spectroscopic data.
Triterpenoids from the Mangrove Plant Hibiscus tiliaceus
Authors: Feng Chao , Li Xiao‐Ming , Ji Nai‐Yun , Wang Bin‐Gui
Published: May 2008

Three new triterpenoids with the rarely occurring nigrum skeleton, namely (20E)‐22‐hydroxynigrum‐20‐en‐3‐one (1), 21β‐hydroxynigrum‐22(29)‐en‐3‐one (2), and 21α‐hydroxynigrum‐22(29)‐en‐3‐one (3), were isolated from the mangrove plant Hibiscus tiliaceus. Additionally, five known triterpenoids including friedelin (4), 12‐oleanen‐3β‐ol (5), 3β‐hydroxy‐12‐oleanen‐28‐oic acid (6), 20(29)‐lupen‐3β,28‐diol (7), and cucurbita‐5,23‐dien‐3β,25‐diol (8) were also isolated and identified. The latter structures were elucidated by a detailed NMR and MS analyses, as well as by comparison with reported literature data.
Six New Cembranolides from the Hainan Soft Coral Lobophytum sp.
Authors: Chen Si‐Han , Guo Yue‐Wei , Huang Hui , Cimino Guido
Published: May 2008

Six new cembrane diterpenes, lobophytolides A–F (1–6, resp.), along with six known related cembranoids, 7–12, were isolated from the Hainan soft coral Lobophytum sp. Their structures, including their relative configuration, were elucidated by extensive analyses of the spectroscopic data and by comparison with related known compounds.
Correlation of Hydrolysis and Desilylation of 2‐[(Trimethylsilyl)methyl]acrylate Derivatives in Aqueous Alkali Solutions
Authors: Kuroda Chiaki , Sunakawa Takeshi , Muguruma Yuichi
Published: May 2008

Hydrolysis and desilylation reaction of 2‐[(trimethylsilyl)methyl]acrylate (=2‐[(trimethylsilyl)methyl]prop‐2‐enoate) derivatives were studied to evaluate the effect of the presence/absence of a further conjugating substituent (Schemes 3 and 4 and Tables 1 and 2). The substrates having a nonconjugating substituent at the acrylate moiety were stable to dilute alkali conditions, and afforded simple hydrolysis products under concentrated alkali conditions. In contrast, both hydrolysis and desilylation occurred from the substrates bearing conjugated substituents at the acrylate skeleton. The difference in reactivity can be explained in terms of the stabilization of the intermediate anion.
Five New Xanthenone O‐Glycosides from the Roots of Polygala sibirica L.
Authors: Zhou Yu‐Hong , Jiang Yong , Shi Hai‐Ming , Chen Yu‐Ping , Tu Peng‐Fei
Published: May 2008

Five new xanthenone O‐glycosides, sibiricaxanthone C (1), sibiricaxanthone D (2), sibiricaxanthone E (3), sibiricaxanthone F (4), and sibiricaxanthone G (5) were isolated from the roots of Polygala sibirica L., together with the six known xanthenone glycosides 6–11. The structures of new compounds were elucidated on the basis of spectral data and acid hydrolysis.
Daphnoldines A and B, Two New Yuzurine Alkaloids with a Four‐Ring System, from the Fruits of Daphniphyllum oldhami
Authors: Zhang Qiang , Di Ying‐Tong , Liu Hai‐Yang , Kong Ning‐Chuan , Gao Suo , Li Chun‐Shun , Zhang Yu , Li Shun‐Lin , Hao Xiao‐Jiang
Published: May 2008

Two new yuzurine alkaloids, daphnoldines A (1) and B (2), possessing a rare four‐ring system, were isolated from the fruits of Daphniphyllum oldhami. Their structures were established on the basis of extensive spectroscopic analyses. Daphnoldine A (1) is the first example of Daphniphyllum alkaloids bearing a hydroxymethyl group at C(14).
Five New Eremophilane Sesquiterpenes from Ligularia przewalskii
Authors: Xu Ji‐Qing , Hu Li‐Hong
Published: May 2008

Five new eremophilane‐type sesquiterpenes, 3β‐(acetyloxy)‐7‐hydroxynoreremophila‐6,9‐dien‐8‐one (1), 8β‐hydroxy‐2‐dehydroxyliguhodgsonal (2), 3β‐(acetyloxy)‐11‐methoxy‐8‐oxoeremophila‐6,9‐dien‐12‐oic acid (3), 3β‐(acetyloxy)‐11‐(2′‐methylbutanoyloxy)‐8‐oxoeremophila‐6,9‐dien‐12‐oic acid (4), and 3β‐(acetyloxy)‐6α‐hydroxyligularenolide (5), along with the three known compounds 6–8, were isolated from the roots of Ligularia przewalskii. The structures of the new compounds were elucidated through spectral studies including HR‐EI‐MS, IR, and NMR data.
Cassane‐Type Diterpenoids from the Seeds of Caesalpinia magnifoliolata
Authors: Yin Yinhua , Ma Lei , Hu Li‐Hong
Published: May 2008

Two novel cassane‐type diterpenes, named magnicaesalpin (1) and neocaesalpin O (2), together with three known compounds, caesalmin D (3), caesalmin E (4), and neocaesalpin L (5), were isolated from the MeOH extract of seeds of Caesalpinia magnifoliolata Metc. Their structures were determined by spectroscopic methods, (1D‐ and 2D‐NMR, HR‐EI‐MS) and X‐ray analysis, as well as by comparison of their spectral data with those of related compounds.
Two New Furanoid Diterpenoids from Tinospora sagittata
Authors: Shi Lin‐Mei , Li Rong‐Qun , Liu Wen‐Hong
Published: May 2008

Two new clerodane‐based furanoid diterpenoids, tinosagittones A and B (1 and 2, resp.), were isolated from the roots of Tinospora sagittata, together with five known diterpenoids, i.e., columbin (3), its glucoside palmatoside C (4), isocolumbin (5), 6‐hydroxycolumbin (6), and tinophylloloside (7). Their structures were established by mass spectrometry and spectroscopic methods, especially 2D‐NMR techniques.
Regulation of nitrogen metabolism in Mycobacterium tuberculosis: A comparison with mechanisms in Corynebacterium glutamicum and Streptomyces coelicolor
Authors: Harper Catriona , Hayward Don , Wiid Ian , van Helden Paul
Published: May 2008

The mechanisms governing the regulation of nitrogen metabolism in Corynebacterium glutamicum and Streptomyces coelicolor have been extensively studied. These Actinomycetales are closely related to the Mycobacterium genus and may therefore serve as a models to elucidate the cascade of nitrogen signalling in other mycobacteria. Some factors involved in nitrogen metabolism in Mycobacterium tuberculosis have been described, including glutamine synthetase and its adenylyltransferase, but not much data concerning the other components involved in the signalling cascade is available. In this review a comparative study of factors involved in nitrogen metabolism in C. glutamicum and S. coelicolor is made to identify similarities with M. tuberculosis on both a genomic and proteomic level. This may provide insight into a potential global mechanism of nitrogen control in Mycobacterium tuberculosis. © 2008 IUBMB IUBMB Life, 60(10): 643–650, 2008