bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generation of cell diversity and segmental pattern in the embryonic central nervous system of Drosophila
Authors: Technau Gerhard M. , Berger Christian , Urbach Rolf 
Published: October 2005

AbstractDevelopment of the central nervous system (CNS) involves the transformation of a two‐dimensional epithelial sheet of uniform ectodermal cells, the neuroectoderm, into a highly complex three‐dimensional structure consisting of a huge variety of different neural cell types. Characteristic numbers of each cell type become arranged in reproducible spatial patterns, which is a prerequisite for the establishment of specific functional contacts. The fruitfly Drosophila is a suitable model to approach the mechanisms controlling the generation of cell diversity and pattern in the developing CNS, as it allows linking of gene function to individually identifiable cells. This review addresses aspects of the formation and specification of neural stem cells (neuroblasts) in Drosophila in the light of recent studies on their segmental diversification. Developmental Dynamics 235:861–869, 2006. © 2005 Wiley‐Liss, Inc.
Hoxa2 knockdown in Xenopus results in hyoid to mandibular homeosis
Authors: Baltzinger Mireille , Ori Michela , Pasqualetti Massimo , Nardi Irma , Rijli Filippo M. 
Published: October 2005

AbstractThe skeletal structures of the face and throat are derived from cranial neural crest cells (NCCs) that migrate from the embryonic neural tube into a series of branchial arches (BAs). The first arch (BA1) gives rise to the upper and lower jaw cartilages, whereas hyoid structures are generated from the second arch (BA2). The Hox paralogue group 2 (PG2) genes, Hoxa2 and Hoxb2, show distinct roles for hyoid patterning in tetrapods and fishes. In the mouse, Hoxa2 acts as a selector of hyoid identity, while its paralogue Hoxb2 is not required. On the contrary, in zebrafish Hoxa2 and Hoxb2 are functionally redundant for hyoid arch patterning. Here, we show that in Xenopus embryos morpholino‐induced functional knockdown of Hoxa2 is sufficient to induce homeotic changes of the second arch cartilage. Moreover, Hoxb2 is downregulated in the BA2 of Xenopus embryos, even though initially expressed in second arch NCCs, similar to mouse and unlike in zebrafish. Finally, Xbap, a gene involved in jaw joint formation, is selectively upregulated in the BA2 of Hoxa2 knocked‐down frog embryos, supporting a hyoid to mandibular change of NCC identity. Thus, in Xenopus Hoxa2 does not act redundantly with Hoxb2 for BA2 patterning, similar to mouse and unlike in fish. These data bring novel insights into the regulation of Hox PG2 genes and hyoid patterning in vertebrate evolution and suggest that Hoxa2 function is required at late stages of BA2 development. Developmental Dynamics 234:858–867, 2005. © 2005 Wiley‐Liss, Inc.
Zebrafish KLF4 is essential for anterior mesendoderm/pre‐polster differentiation and hatching
Authors: Gardiner Melissa R. , Daggett David F. , Zon Leonard I. , Perkins Andrew C. 
Published: October 2005

AbstractGene knockout studies of Krüppel‐like factors (KLFs) in mice have shown essential roles in organogenesis. A screen for KLF family members in zebrafish identified many KLFs. One of these, zebrafish KLF4 (zKLF4) is the homologue of neptune, a Xenopus laevis KLF. zKLF4 is expressed from approximately 80% epiboly a patch of dorsal/anterior mesendodermal cells called the pre‐polster and, subsequently, in the polster and hatching gland. Here we investigate the function of zKLF4 using morpholino‐based antisense oligonucleotides. Knockdown of zKLF4 resulted in complete absence of hatching gland formation and subsequent hatching in zebrafish. In addition, there was early knockdown of expression of the pre‐polster/anterior mesendoderm markers CatL, cap1, and BMP4. These results indicate zKLF4 is expressed within the pre‐polster, an early mesendodermal site, and that it plays a critical role in the differentiation of these cells into hatching gland cells. Developmental Dynamics 234:992–996, 2005. © 2005 Wiley‐Liss, Inc.
Tbx3, the ulnar‐mammary syndrome gene, and Tbx2 interact in mammary gland development through a p19Arf/p53‐independent pathway
Authors: Jerome‐Majewska Loydie A. , Jenkins Gerard P. , Ernstoff Elana , Zindy Frederique , Sherr Charles J. , Papaioannou Virginia E. 
Published: October 2005

AbstractThe closely related T‐box genes Tbx2 and Tbx3 are both expressed in the developing mammary glands of mouse embryos and both have been implicated in mammary carcinogenesis. Tbx3 is essential for induction of the mammary placodes in mice. In humans, mutations in TBX3 are responsible for ulnar‐mammary syndrome. Here, we show a haploinsufficiency effect of Tbx3 on maintenance of the mammary placodes and on the extent of branching of the ductal tree in mice. Loss or heterozygosity for Tbx2, on the other hand, has no effect on either induction or maintenance of the placodes, although a small effect was seen on branching morphogenesis in adult heterozygotes. However, the deficiency in maintenance of the mammary placodes in Tbx2, Tbx3 double heterozygous mice is more marked than in Tbx3 single heterozygotes, indicating a genetic interaction between the two genes. In spite of a large body of evidence implicating these genes in cell cycle control through the p19Arf/p53 pathways, we find no evidence for involvement of these pathways either in embryonic lethality of homozygous mutants or in the mammary gland phenotype of Tbx3 heterozygous mice. Developmental Dynamics 234:922–933, 2005. © 2005 Wiley‐Liss, Inc.
High‐Pressure Assisted Synthesis of Fused Norbornenes Containing Two7‐Metallonorbornene Units
Authors: Eckert‐Maksić Mirjana , Margetić Davor , Kirin Srećko , Milić Dalibor , Matković‐Čalogović Dubravka 
Published: October 2005

AbstractThe high‐pressure synthesis of new rod‐like and U‐shaped polycyclic compounds containing two 7‐metallonorbornene (silicon or germanium) units fused to the 7‐oxanorbornene rings is described. In addition, the structural features of adduct 9 established by X‐ray structure determination and DFT calculations of model compounds are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Consequences of P‐Chirality in Chimeric 2′‐O‐Methyloligoribonucleotides with Stereoregular Methylphosphonothioate Linkages
Authors: Wozniak Lucyna A. , Janicka Magdalena , Bukowiecka‐Matusiak Małgorzata 
Published: October 2005

AbstractStereoregular chimeric oligonucleotides modified with diastereomerically pure methylphosphonothioate linkages interact with complementary DNA or RNA templates in a stereodependent manner. There is an unprecedented large difference in the stability of duplexes of oligonucleotides modified with alternating methylphosphonothioate linkages (ΔTm = 34 °C) that is dependent only on the stereochemistry of the methylphosphonothioate phosphorus centres. The nature of these interactions was studied by circular dichroism and NMR spectroscopy, and a thermodynamic analysis was performed. The collected data indicate that the absolute configuration at the P‐chiral methylphosphonothioate linkages in chimeric 2′‐O‐methylribonucleotides could, in some cases, determine the global conformation of single–strand oligonucleotides and constrain the conformation of hybrid duplexes formed with RNA. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Chemoselective Lithiation of 1‐Bromo‐n‐chloroalkanes
Authors: Foubelo Francisco , Abou Abdeslam , Yus Miguel 
Published: October 2005

AbstractReactions between different 1‐bromo‐n‐chloroalkanes (1–3), lithium/naphthalene (1:2 molar ratio) and a carbonyl compound R1R2CO in THF at –78 °C provide, after hydrolysis with water, the corresponding chlorinated alcohols 4 through selective lithiation of the carbon–bromine bond. When an excess of lithium (1:7 molar ratio) is added to the reaction mixture before the hydrolysis, lithiation of the remaining carbon–chlorine bond takes place. The addition of a second carbonyl compound R3R4CO, followed by hydrolysis, affords the corresponding diols 7. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Application of Diffusion‐Ordered Spectroscopy (DOSY) as a Solvent Signal Filter for NMR in Neat Ionic Liquids
Authors: Giernoth Ralf , Bankmann Dennis 
Published: October 2005

AbstractThe use of common, that is nondeuterated, ionic liquids for NMR spectroscopic purposes as the only solvent causes large signals arising from solvent resonances. Ionic liquids (ILs) with long side chains possess signals throughout the spectral range of protons, thus rendering simple solvent signal suppression techniques ineffective. Here we present solvent signal suppression based on diffusion‐ordered NMR spectroscopy (DOSY). In contrast to the well established usage of DOSY to filter water resonances from biological systems, here we filter out the slower moving molecules. This method allows in many cases for the complete removal of the solvent signals from 1H spectra of solutes and may become a useful tool for in situ studies of reactions performed in ILs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A Novel Bis(zinc–porphyrin)–Oxoporphyrinogen Donor–Acceptor Triad: Synthesis, Electrochemical, Computational and Photochemical Studies
Authors: Hill Jonathan P. , Sandanayaka Atula S. D. , McCarty Amy L. , Karr Paul A. , Zandler Melvin E. , Charvet Richard , Ariga Katsuhiko , Araki Yasuyuki , Ito Osamu , D'Souza Francis 
Published: October 2005

AbstractThe first example of a porphyrin‐quinonoid donor–acceptor triad featuring (tetraphenylporphinato)zinc(II) moieties covalently attached to an oxoporphyrinogen through its macrocyclic nitrogen atoms is reported. This arrangement of chromophores results in an interesting interplay between the electron‐donating zinc–porphyrin(s) and the electron/energy accepting oxoporphyrinogen. The optical absorption of the triad reveals features corresponding to both the donor and acceptor entities. The geometry and electronic structure of the triad deduced from B3LYP/3‐21G(*) calculations reveal an absence of inter‐chromophoric interactions and localization of the HOMO on one zinc–porphyrin group and the LUMO on the oxoporphyrinogen scaffold. The electrochemical redox states of the triad were established from a comparative electrochemistry of the triad and the reference compounds. Both steady‐state and time‐resolved emission studies revealed quenching of the singlet excited state of zinc–porphyrin in the triad, and the free‐energy calculations performed using Weller’s approach indicate the possibility of electron transfer from the singlet excited zinc–porphyrin group to the oxoporphyrinogen in polar solvents. Time‐resolved fluorescence studies reveal excited state energy transfer from zinc–porphyrin to oxoporphyrinogen in nonpolar solvents, while nanosecond transient absorption studies combined with time‐resolved fluorescence studies in polar solvents are indicative of the occurrence of photoinduced charge separation from the singlet excited zinc–porphyrin to the oxoporphyrinogen. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Segregation of micron‐scale membrane sub‐domains in live murine sperm
Authors: Selvaraj Vimal , Asano Atsushi , Buttke Danielle E. , McElwee John L. , Nelson Jacquelyn L. , Wolff Collin A. , Merdiushev Tanya , Fornés Miguel W. , Cohen Alex W. , Lisanti Michael P. , Rothblat George H. , Kopf Gregory S. , Travis Alexander J. 
Published: October 2005

AbstractLipid rafts, membrane sub‐domains enriched in sterols and sphingolipids, are controversial because demonstrations of rafts have often utilized fixed cells. We showed in living sperm that the ganglioside GM1 localized to a micron‐scale membrane sub‐domain in the plasma membrane overlying the acrosome. We investigated four models proposed for membrane sub‐domain maintenance. GM1 segregation was maintained in live sperm incubated under non‐capacitating conditions, and after sterol efflux, a membrane alteration necessary for capacitation. The complete lack of GM1 diffusion to the post‐acrosomal plasma membrane (PAPM) in live cells argued against the transient confinement zone model. However, within seconds after cessation of sperm motility, GM1 dramatically redistributed several microns from the acrosomal sub‐domain to the post‐acrosomal, non‐raft sub‐domain. This redistribution was not accompanied by movement of sterols, and was induced by the pentameric cholera toxin subunit B (CTB). These data argued against a lipid–lipid interaction model for sub‐domain maintenance. Although impossible to rule out a lipid shell model definitively, mice lacking caveolin‐1 maintained segregation of both sterols and GM1, arguing against a role for lipid shells surrounding caveolin‐1 in sub‐domain maintenance. Scanning electron microscopy of sperm freeze‐dried without fixation identified cytoskeletal structures at the sub‐domain boundary. Although drugs used to disrupt actin and intermediate filaments had no effect on the segregation of GM1, we found that disulfide‐bonded proteins played a significant role in sub‐domain segregation. Together, these data provide an example of membrane sub‐domains extreme in terms of size and stability of lipid segregation, and implicate a protein‐based membrane compartmentation mechanism. © 2005 Wiley‐Liss, Inc.
Flavonoids inhibit melanoma lung metastasis by impairing tumor cells endothelium interactions
Authors: Piantelli Mauro , Rossi Cosmo , Iezzi Manuela , La Sorda Rossana , Iacobelli Stefano , Alberti Saverio , Natali Pier Giorgio 
Published: October 2005

AbstractFlavonoids comprise a class of low molecular weight compounds displaying a variety of biological activities including inhibition of tumor growth and metastasis. To gain insight into the mechanisms underlying metastasis inhibition, we have employed the B16‐BL6 murine melanoma metastasis model. B57BL/6N mice were injected i.v. with tumor cells and Apigenin, Quercetin, or Tamoxifen, each at 50 mg/kg given i.p., and lung tumor cell colonies counted 14–6 days thereafter. Three different injection schedules were used for each drug: (a) daily injection, starting 24 h before injection of the tumor cells; (b) single dose, 24 h preceding tumor challenge; (c) daily injection, starting 24 h after the injection of the tumor cells. All three compounds significantly reduced tumor lung deposits (Apigenin = Quercetin > Tamoxifen). However, when treatment was delayed by 24 h after tumor cells (schedule c), multiple daily doses of Apigenin or Quercetin were less effective that a single dose of the same compound given 24 h before tumor challenge (schedule b). Apigenin and Quercetin, but not Tamoxifen, were found to inhibit VCAM‐1 expression in a dose‐dependent manner in HUVEC and in murine pulmonary endothelial cells. In ex vivo experiments, the number of tumor cells adhering to lung vessels was significantly diminished in animals treated with a single dose of Apigenin and Quercetin. These findings indicate that the inhibition of tumor cell metastasis by Apigenin or Quercetin may significantly depend on the ability of these compounds to alter the host's microenvironment, further substantiating the role of the intravascular processes in the metastatic cascade. J. Cell. Physiol. 207: 23–29, 2006. © 2005 Wiley‐Liss, Inc.
D‐aspartic acid in the nervous system of Aplysia limacina: Possible role in neurotransmission
Authors: Spinelli Patrizia , Brown Euan R. , Ferrandino Gabriele , Branno Margherita , Montarolo Pier Giorgio , D'Aniello Enrico , Rastogi Rakesh K. , D'Aniello Biagio , Baccari Gabriella Chieffi , Fisher George , D'Aniello Antimo 
Published: October 2005

AbstractIn the marine mollusk Aplysia limacina, a substantial amount of endogenous D‐aspartic acid (D‐Asp) was found following its synthesis from L‐aspartate by an aspartate racemase. Concentrations of D‐Asp between 3.9 and 4.6 µmol/g tissue were found in the cerebral, abdominal, buccal, pleural, and pedal ganglia. In non nervous tissues, D‐Asp occurred at a very low concentration compared to the nervous system. Immunohistochemical studies conducted on cultured Aplysia neurons using an anti‐D‐aspartate antibody demonstrated that D‐Asp occurs in the soma, dendrites, and in synaptic varicosities. Synaptosomes and synaptic vesicles from cerebral ganglia were prepared and characterized by electron microscopy. HPLC analysis revealed high concentrations of D‐Asp together with L‐aspartate and L‐glutamate in isolated synaptosomes In addition, D‐Asp was released from synaptosomes by K+ depolarization or by ionomycin. D‐Asp was one of the principal amino acids present in synaptic vesicles representing about the 25% of total amino acids present in these cellular organelles. Injection of D‐Asp into live animals or addition to the incubation media of cultured neurons, caused an increase in cAMP content. Taken as a whole, these findings suggest a possible role of D‐Asp in neurotransmission in the nervous system of Aplysia limacina. © 2005 Wiley‐Liss, Inc.
Intracellular localization of ClC chloride channels and their ability to form hetero‐oligomers
Authors: Suzuki Tatsunori , Rai Tatemitsu , Hayama Atsushi , Sohara Eisei , Suda Shin , Itoh Tomohiro , Sasaki Sei , Uchida Shinichi 
Published: October 2005

AbstractClC chloride channels (ClCs) can be classified into two groups in terms of their cellular localizations: ClCs present in the plasma membranes and those residing in intracellular organelles. Members of the latter group, including ClC‐3, ClC‐4, ClC‐5, ClC‐6, and ClC‐7, are often co‐expressed in a variety of cell types in many organs. Although the localization of individual channels within cells has been investigated, the degree of overlap between the locations of different ClCs in the same cell has not been clarified. To address this question, different combinations of ClCs, engineered to encode specific epitope tags (FLAG or HA), were either transiently or stably transfected into HEK293 cells, and we then compared the intracellular localization of the expressed channel proteins by immunofluorescence microscopy. Immunofluorescence images of the alternatively labeled channels clearly showed significant co‐localization between all pair‐wise combinations of ClCs. In particular, ClC‐3, ClC‐4, and ClC‐5 showed a high degree of co‐localization. As a significant degree of co‐localization between ClCs was observed, we used co‐immunoprecipitation to evaluate oligomer formation, and found that each ClC tested could form homo‐oligomers, and that any pair‐wise combination of ClC‐3, ClC‐4, and ClC‐5 could also form hetero‐oligomers. Neither ClC‐6 nor ClC‐7 was co‐precipitated with any other channel protein. These results suggest that within cells ClC‐3, ClC‐4, and ClC‐5 may have combinatorial functions, whereas ClC‐6 and ClC‐7 are more likely to function as homo‐oligomers. © 2005 Wiley‐Liss, Inc.
Interleukin‐1β downregulates the L‐type Ca2+ channel activity by depressing the expression of channel protein in cortical neurons
Authors: Zhou Chen , Tai Chao , Ye Hai Hong , Ren Xi , Chen Jian Gou , Wang Shi‐Qiang , Chai Zhen 
Published: October 2005

AbstractInterleukin‐1β (IL‐1β), a proinflammatory cytokine, has been involved in various diseases of the central nervous system (CNS). Due to the diverse, “contradictory” effects of IL‐1β on neurons during insults to the brain, the mechanisms underlying these effects have not been elucidated. Calcium influx through the L‐type Ca2+ channels (LCCs) is believed to play a critical role in the cascade of biochemical events leading to neuron death in these pathophysiological conditions. So far, the mechanism of the interaction of IL‐1β and LCCs in the initiation and progression of these diseases is unclear. In this study, we investigate systemically the effects of IL‐1β on the LCCs current, which are believed to be implicated in the cascade of biochemical events leading to neuron death in neuropathological conditions. Using patch clamp, we observe that IL‐1β treatment (10 ng/ml, 24 h) suppresses LCC currents by ∼38%, which made up half of the whole‐cell Ca2+ current determined by nifedipine. IL‐1β does not alter the characteristics of single LCC including current amplitude, open probability, and conductance, but decreases the number of the functioning channel by 40%. Moreover, immunoblot assay exhibits that IL‐1β reduces the expression of LCC proteins by 38∼42% in both whole neuron and plasma membrane fraction, and demonstrates that IL‐1β downregulates the LCC activity via the reduction of LCC density. According to early research pretreatments longer than 12 h may play a crucial role in the neuroprotective effects of IL‐1β, our findings may establish an explanation for the protective effects of this interleukin on neurons in the late stage of injury, and could raise a new issue to clinical treatment for insults to brain. © 2005 Wiley‐Liss, Inc.
An approachable human adult stem cell source for hard‐tissue engineering
Authors: Laino Gregorio , Graziano Antonio , d'Aquino Riccardo , Pirozzi Giuseppe , Lanza Vladimiro , Valiante Salvatore , De Rosa Alfredo , Naro Fabio , Vivarelli Elisabetta , Papaccio Gianpaolo 
Published: October 2005

AbstractStem cells were obtained from deciduous dental pulp of healthy subjects, aged 6–10 years. This stem cell population was cultured, expanded, and specifically selected, detecting using a FACsorter, c‐kit, CD34, and STRO‐1 antigen expression. Then, c‐kit+/CD34+/STRO‐1+cells were replaced in the culture medium added of 20% FBS, leading to osteoblast differentiation. In fact, these cells, after a week, showed a large positivity for CD44, osteocalcin, and RUNX‐2 markers. To achieve an adipocytic differentiation, cells, after sorting, were challenged with dexamethason 10−8 mM in the same culture medium. To obtain myotube fusion, sorted cells were co‐cultured in ATCC medium with mouse myogenic C2C12 cells and, after a week, human stem cell nuclei were found to be able to fuse, forming myotubes. Differentiated osteoblasts, as assessed by a large positivity to several specific antibodies, after 30 days of culture and already in vitro, started to secrete an extracellular mineralized matrix, which, 2 weeks later, built a considerable number of 3D woven bone samples, which showed a strong positivity to alkaline phosphatase (ALP), alizarin red, calcein, other than to specific antibodies. These bone samples, after in vivo transplantation into immunosuppressed rats, were remodeled in a lamellar bone containing entrapped osteocytes. Therefore, this study provides strong evidence that human deciduous dental pulp is an approachable “niche” of stromal stem cells, and that it is an ideal source of osteoblasts, as well as of mineralized tissue, ready for bone regeneration, transplantation, and tissue‐based clinical therapies. © 2005 Wiley‐Liss, Inc.