bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inducible and Reversible Transgene Expression in Human Stem Cells After Efficient and Stable Gene Transfer
Authors: Zhou Betty Ying , Ye Zhaohui , Chen Guibin , Gao Zhigang Peter , Zhang Yu A. , Cheng Linzhao 
Published: December 2006

Abstract
We report here a lentiviral vector system for regulated transgene expression. We used the tetracycline repressor fused with a transcriptional suppression domain (tTS) to specifically suppress transgene expression. Human cells were first transduced with a tTS-expressing vector and subsequently transduced with a second lentiviral vector-containing transgene controlled by a regular promoter adjacent to a high-affinity tTS-binding site (tetO). After optimizing the location of the tetO site in the latter vector, we achieved a better inducible transgene expression than the previous lentiviral vectors using the tetracycline repressor systems. In this new system, the transgene transcription from a cellular promoter such as EF1α or ubiquitin-C promoter is suppressed by the tTS bound to the nearby tetO site. In the presence of the tetracycline analog doxycycline (Dox), however, the tTS binding is released from the transgene vector and transcription from the promoter is restored. Thus, this system simply adds an extra level of regulation, suitable for any types of promoters (ubiquitous or cell-specific). We tested this tTS-suppressive, Dox-inducible system in 293T cells, human multipotent hematopoietic progenitor cells, and three human embryonic stem cell lines, using a dual-gene vector containing the green fluorescent protein reporter or a cellular gene. We observed a tight suppression in the uninduced state. However, the suppression is reversible, and transgene expression was restored at 5 ng/ml Dox. The lentiviral vectors containing the tTS-suppressive, Dox-inducible system offer a universal, inducible, and reversible transgene expression system in essentially any mammalian cell types, including human embryonic stem cells.
Progression of mycosis of the auditory tube diverticulum (guttural pouch) after arterial occlusion in a horse with contralateral temporohyoid osteoarthropathy
Authors: Ernst Nicolas S. , Freeman David E. , MacKay Robert J. 
Published: December 2006

Abstract
Case Description—A 6-year-old Appaloosa mare was examined because of inappetance, difficulty eating, and swelling and mucopurulent discharge in the right eye.
Clinical Findings—Results of a CBC and serum bio-chemical analysis revealed no important findings. Ophthalmologic examination revealed scarring and ulcer-ation of the superficial layers of the cornea. Endoscopic examination of the upper portion of the respiratory tract and auditory tube diverticula (guttural pouches) revealed abnormal thickness of the right stylohyoid bone and a plaque suggestive of mycotic growth on the left internal carotid artery. Radiographic examination revealed right-sided otitis media. Temporohyoid osteoarthropathy in the right guttural pouch and mycosis in the left guttural pouch were diagnosed.
Treatment and Outcome—Ceratohyoidectomy of the right stylohyoid bone was performed, and the left internal carotid artery was occluded via placement of stainless steel spring embolization coils. The mare regained the ability to eat without difficulty and improved clinically for approximately 4 weeks. However, the mare returned to the medical center 53 days after surgery with left-sided Horner syndrome, atrophy of the right side of the tongue, and a 3-week history of dysphagia and weight loss. Endoscopic evaluation revealed progression of mycotic growth in the left guttural pouch. The mare was euthanatized.
Clinical Relevance—Although the mycotic lesion in the left guttural pouch was an incidental finding at the time of initial examination, the lesion progressed to cause dysphagia and Horner syndrome after occlusion of the left internal carotid artery, a treatment that is typically associated with resolution of guttural pouch mycosis. Arterial occlusion is not necessarily a reliable method of resolving guttural pouch mycosis.
Nanostructures by self‐assembling peptide amphiphile as potential selective drug carriers
Authors: Accardo Antonella , Tesauro Diego , Mangiapia Gaetano , Pedone Carlo , Morelli Giancarlo 
Published: December 2006

AbstractThe self‐assembling behavior, at physiological pH, of the amphiphile peptide (C18)2L5CCK8 in nanostructures is reported. Stable aggregates presenting a critical micellar concentration of 2 × 10−6 mol kg−1, and characterized by water exposed CCK8 peptide in β‐sheet conformation, are obtained. Small angle neutron scattering experiments are indicative for a 3D structure with dimensions ≥100 nm. AFM images confirm the presence of nanostructures. Fluorescence experiments indicating the sequestration of pyrene, chosen as drug model, and the anticancer Doxorubicin within the nanostructures are reported. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 88: 115–121, 2007.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Solvent Polarity Controls the Helical Conformation of Short Peptides Rich in Cα‐Tetrasubstituted Amino Acids
Authors: Bellanda Massimo , Mammi Stefano , Geremia Silvano , Demitri Nicola , Randaccio Lucio , Broxterman Quirinus B. , Kaptein Bernard , Pengo Paolo , Pasquato Lucia , Scrimin Paolo 
Published: December 2006

AbstractThe two peptides, rich in Cα‐tetrasubstituted amino acids, Ac‐[Aib‐L‐(αMe)Val‐Aib]2‐L‐His‐NH2 (1) and Ac‐[Aib‐L‐(αMe)Val‐Aib]2‐O‐tBu (2 a) are prevalently helical. They present the unique property of changing their conformation from the α‐ to the 310‐helix as a function of the polarity of the solvent: α in more polar solvents, 310 in less polar ones. Conclusive evidence of this reversible change of conformation is reported on the basis of the circular dichroism (CD) spectra and a detailed two‐dimensional NMR analysis in two solvents (trifluoroethanol and methanol) refined with molecular dynamics calculations. The X‐ray diffractometric analysis of the crystals of both peptides reveals that they assume a prevalent 310‐helix conformation in the solid state. This conformation is practically superimposable on that obtained from the NMR analysis of 1 in methanol. The NMR results further validate the reported CD signature of the 310‐helix and the use of the CD technique for its assessment.
3D Architectures of Iron Molybdate: Phase Selective Synthesis, Growth Mechanism, and Magnetic Properties
Authors: Ding Yi , Yu Shu‐Hong , Liu Chen , Zang Zheng‐An 
Published: December 2006

AbstractMonoclinic and orthorhombic Fe2(MoO4)3 microsized particles with complex 3D architectures have been selectively prepared by a template‐free hydrothermal process. The pH value, reaction time, temperature, and molybdenian source have crucial influence on the phase formation, shape evolution, and microstructures. Monoclinic Fe2(MoO4)3 particles obtained at pH 1 and pH 1.65 display ferromagnetic ordering at 10.4 K and 10.5 K, respectively, and the ferromagnetic component is determined to be 0.0458 μB and 0.0349 μB per Fe‐ion at 10 K, respectively. For orthorhombic β‐Fe2(MoO4)3, antiferromagnetic ordering was observed about 12 K. At higher temperatures, β‐Fe2(MoO4)3 began to follow the Curie–Weiss law with θ=−70 K. Such 3D architectures of monoclinic and orthorhombic β‐Fe2(MoO4)3 microparticles with unique shapes and structural characteristics may find applications as catalysts and as well as in other fields.
Drosophila photoreceptors express cysteine peptidase tan
Authors: Wagner Stefanie , Heseding Christiane , Szlachta Kamila , True John R. , Prinz Heino , Hovemann Bernhard T. 
Published: December 2006

AbstractThe Drosophila mutant tan (t) shows reciprocal pigmentation defects compared with the ebony (e) mutant. Visual phenotypes, however, are similar in both flies: Electroretinogram (ERG) recordings lack “on” and “off” transients, an indication of impaired synaptic transmission to postsynaptic cells L1 and L2. Cloning of tan revealed transcription of the gene in the retina, apparently in photoreceptor cells. We expressed Tan in Escherichia coli and confirmed by Western blotting and mass spectroscopic analyses that Tan is expressed as preprotein, followed by proteolytic cleavage into two subunits at a conserved —Gly—Cys— motif like its fungal ortholog isopenicillin‐N N‐acyltransferase (IAT). Tan thus belongs to the large family of cysteine peptidases. To discriminate expression of Tan and Ebony in retina and optic neuropils, we raised antisera against specific Tan peptides. Testing for colocalization with GMR‐driven n‐Syb‐GFP labeling revealed that Tan expression is confined to the photoreceptor cells R1–R8. A close proximity of Tan and Ebony expression is evident in lamina cartridges, where three epithelial glia cells envelop the six photoreceptor terminals R1–R6. In the medulla, R7/R8 axonal terminals appeared lined up side by side with glial extensions. This local proximity supports a model for Drosophila visual synaptic transmission in which Tan and Ebony interact biochemically in a putative histamine inactivation and recycling pathway in Drosophila. J. Comp. Neurol. 500:601–611, 2007. © 2006 Wiley‐Liss, Inc.
Expression of GATA3 and tenascin in the avian vestibular maculae: Normative patterns and changes during sensory regeneration
Authors: Warchol Mark E. , Speck Judith D. 
Published: December 2006

AbstractSensory receptors in the vestibular organs of birds can regenerate after ototoxic injury. Notably, this regenerative process leads to the restoration of the correct patterning of hair cell phenotype and afferent innervation within the repaired sensory epithelium. The molecular signals that specify cell phenotype and regulate neuronal guidance during sensory regeneration are not known, but they are likely to be similar to the signals that direct these processes during embryonic development. The present study examined the recovery of hair cell phenotype during regeneration in the avian utricle, a vestibular organ that detects linear acceleration and head orientation. First, we show that Type I hair cells in the avian vestibular maculae are immunoreactive for the extracellular matrix molecule tenascin and that treatment with the ototoxic antibiotic streptomycin results in a nearly complete elimination of tenascin immunoreactivity. Cells that express tenascin begin to recover after about 2 weeks and are then contacted by calyx terminals of vestibular neurons. In addition, our previous work had shown that the zinc finger transcription factor GATA3 is uniquely expressed within the striolar reversal zone of the utricle (Hawkins et al. [2003] Hum Mol Genet 12:1261–1272), and we show here that this regionalized expression of GATA3 is maintained after severe hair cell lesions and after transplantation of the sensory epithelium onto a chemically defined substrate. In contrast, the expression of three other supporting cell markers—α‐ and β‐tectorin and SCA—is reduced following ototoxic injury. These observations suggest that GATA3 expression may maintain positional information in the maculae during sensory regeneration. J. Comp. Neurol. 500:646–657, 2007. © 2006 Wiley‐Liss, Inc.
Effects of double and triple bonds on the spatial representations of odorants in the rat olfactory bulb
Authors: Johnson Brett A. , Ong Joan , Lee Kaman , Ho Sabrina L. , Arguello Spart , Leon Michael 
Published: December 2006

AbstractMany naturally occurring volatile chemicals that are detected through the sense of smell contain unsaturated (double or triple) carbon‐carbon bonds. These bonds can affect odors perceived by humans, yet in a prior study of unsaturated hydrocarbons we found only very minor effects of unsaturated bonds. In the present study, we tested the possibility that unsaturated bonds affect the recognition of oxygen‐containing functional groups, because humans perceive odor differences between such molecules. We therefore compared spatial activity patterns across the entire glomerular layer of the rat olfactory bulb evoked by oxygen‐containing odorants differing systematically in the presence, position, number, and stereochemistry of unsaturated bonds. We quantified activity patterns by mapping [14C]2‐deoxyglucose uptake into anatomically standardized data matrices, which we compared statistically. We found that the presence and number of unsaturated bonds consistently affected activity patterns, with the largest effect related to the presence of a triple bond. Effects of bond saturation included a loss of activity in glomeruli strongly activated by the corresponding saturated odorants and/or the presence of activity in areas not stimulated by the corresponding saturated compounds. The position of double bonds also affected patterns of activity, but cis vs. trans configuration had no measurable impact in all five sets of stereoisomers that we studied. These results simultaneously indicate the importance of interactions between carbon‐carbon bond types and functional groups in the neural coding of odorant chemical information and highlight the emerging concept that the rat olfactory system is more sensitive to certain types of chemical differences than others. J. Comp. Neurol. 500:720–733, 2007. © 2006 Wiley‐Liss, Inc.
Entorhinal cortex of the monkey: VII. Intrinsic connections
Authors: Chrobak James J. , Amaral David G. 
Published: December 2006

AbstractThe organization of intrinsic connections within the entorhinal cortex was investigated in Macaca fascicularis monkeys. Anterograde tracers (3H‐amino acids, Phaseolus vulgaris‐leucoagglutinin, biotinylated dextran amine, or Fluoro‐Ruby) were injected into the deep or superficial layers of the entorhinal cortex in 24 animals. These injections labeled extensive intrinsic projections that terminated throughout all layers of the entorhinal cortex. Labeling was typically continuous i.e., there was no evidence of a patchy or columnar organization. Each injection produced a rostrocaudally oriented band of labeled fibers and terminals that extended for one‐third to one‐half of the length of the entorhinal cortex. The more extensive distributions of labeled fibers were more typical of caudally placed injection sites. Taken together, the projections identified at least two mediolaterally differentiated bands: a lateral band that encompasses fields Elr, Elc, and the most lateral aspect of fields Ec and Ecl and a wider, medially situated band that encompasses much of fields Er, Ei, Ec, and Ecl. We obtained some evidence that field Eo constitutes a third, very medially placed band. The rostrocaudal organization of labeled fibers and the extent of labeling within the deep and superficial layers were unrelated to the laminar position of the injection. These data suggest that intrinsic associatonal connections in the monkey entorhinal cortex are organized into separate associational networks. Our findings are discussed with reference to the role of interlaminar connections in mediating physiological interactions between the neocortex and the hippocampus. J. Comp. Neurol. 500:612–633, 2007. © 2006 Wiley‐Liss, Inc.
Diversity of glycine receptors in the mouse retina: Localization of the α4 subunit
Authors: Heinze Liane , Harvey Robert J. , Haverkamp Silke , Wässle Heinz 
Published: December 2006

AbstractGlycine and γ‐aminobutyric acid (GABA) are the major inhibitory neurotransmitters in the retina. Approximately half of the amacrine cells release glycine at their synapses with bipolar, other amacrine, and ganglion cells. Whereas the retinal distributions of glycine receptor (GlyR) subunits α1, α2, and α3 have been mapped, the role of the α4 subunit in retinal circuitry remains unclear. A rabbit polyclonal antiserum was raised against a peptide that comprises the C‐terminal 14 amino acids of the mouse GlyR α4 subunit. Using immunocytochemistry, we localized the α4 subunit in the inner plexiform layer (IPL) in brightly fluorescent puncta, which represent postsynaptically clustered GlyRs. This was shown by double‐labeling sections for GlyR α4 and synaptic markers (bassoon, gephyrin). Double‐labeling sections for GlyR α4 and the other GlyR α subunits shows that they are mostly clustered at different synapses; however, ∼30% of the α4‐containing synapses also express the α2 subunit. We also studied the pre‐ and postsynaptic partners at GlyR α4‐containing synapses and found that displaced (ON‐) cholinergic amacrine cells prominently expressed the α4 subunit. The density of GlyR α4‐expressing synapses in wildtype, Glra1ot/ot, and Glra3−/− mouse retinas did not differ significantly. Thus, there is no apparent compensation of the loss of α1 or α3 subunits by an upregulation of α4 subunit gene expression; however, the α2 subunit is moderately upregulated. J. Comp. Neurol. 500:693–707, 2007. © 2006 Wiley‐Liss, Inc.
Hypothalamic and brainstem sources of pituitary adenylate cyclase‐activating polypeptide nerve fibers innervating the hypothalamic paraventricular nucleus in the rat
Authors: Das Mahasweta , Vihlen Christopher S. , Legradi Gabor 
Published: December 2006

AbstractThe hypothalamic paraventricular nucleus (PVN) coordinates major neuroendocrine and behavioral mechanisms, particularly responses to homeostatic challenges. Parvocellular and magnocellular PVN neurons are richly innervated by pituitary adenylate cyclase‐activating polypeptide (PACAP) axons. Our recent functional observations have also suggested that PACAP may be an excitatory neuropeptide at the level of the PVN. Nevertheless, the exact localization of PACAP‐producing neurons that project to the PVN is not understood. The present study examined the specific contribution of various brain areas sending PACAP innervation to the rat PVN by using iontophoretic microinjections of the retrograde neuroanatomical tracer cholera toxin B subunit (CTb). Retrograde transport was evaluated from hypothalamic and brainstem sections by using multiple labeling immunofluorescence for CTb and PACAP. PACAP‐containing cell groups were found to be retrogradely labeled from the PVN in the median preoptic nucleus; preoptic and lateral hypothalamic areas; arcuate, dorsomedial, ventromedial, and supramammillary nuclei; ventrolateral midbrain periaqueductal gray; rostral and midlevel ventrolateral medulla, including the C1 catecholamine cell group; nucleus of the solitary tract; and dorsal motor nucleus of vagus. Minor PACAP projections with scattered double‐labeled neurons originated from the parabrachial nucleus, pericoeruleus area, and caudal regions of the nucleus of the solitary tract and ventrolateral medulla. These observations indicate a multisite origin of PACAP innervation to the PVN and provide a strong chemical neuroanatomical foundation for interaction between PACAP and its potential target neurons in the PVN, such as parvocellular CRH neurons, controlling physiologic responses to stressful challenges and other neuroendocrine or preautonomic PVN neurons. J. Comp. Neurol. 500:761–776, 2007. © 2006 Wiley‐Liss, Inc.
Steady‐state 3D rolling‐contact using boundary elements
Authors: Abascal R. , Rodríguez‐Tembleque L. 
Published: December 2006

Abstract
This work presents a new approach to the steady‐state rolling contact problem for 3D elastic bodies. The problem solution is achieved by minimizing a general function representing the equilibrium equation and the rolling‐contact restrictions. The boundary element method is used to compute the elastic influence coefficients of the surface points involved in the contact (equilibrium equations); while the contact conditions are represented with the help of projection functions. Finally, the minimization problem is solved by the generalized Newton's method with line search. Classic rolling problems are also solved and commented. Copyright © 2006 John Wiley & Sons, Ltd.
TBid mediated activation of the mitochondrial death pathway leads to genetic ablation of the lens in Xenopus laevis
Authors: Du Pasquier D. , Chesneau A. , Ymlahi‐Ouazzani Q. , Boistel R. , Pollet N. , Ballagny C. , Sachs L.M. , Demeneix B. , Mazabraud A. 
Published: December 2006

AbstractXenopus is a well proven model for a wide variety of developmental studies, including cell lineage. Cell lineage in Xenopus has largely been addressed by injection of tracer molecules or by micro‐dissection elimination of blastomeres. Here we describe a genetic method for cell ablation based on the use of tBid, a direct activator of the mitochondrial apoptotic pathway. In mammalian cells, cross‐talk between the main apoptotic pathways (the mitochondrial and the death domain protein pathways) involve the pro‐death protein BID, the active form of which, tBID, results from protease truncation and translocation to mitochondria. In transgenic Xenopus, restricting tBID expression to the lens‐forming cells enables the specific ablation of the lens without affecting the development of other eye structures. Thus, overexpression of tBid can be used in vivo as a tool to eliminate a defined cell population by apoptosis in a developing organism and to evaluate the degree of autonomy or the inductive effects of a specific tissue during embryonic development. genesis 45:1–10, 2007. © 2006 Wiley‐Liss, Inc.
Transient expression of FOXP3 in human activated nonregulatory CD4+ T cells
Authors: Wang Jun , Ioan‐Facsinay Andreea , van der Voort Ellen I. H. , Huizinga Tom W. J. , Toes René E. M. 
Published: December 2006

AbstractFoxp3 plays a key role in CD4+CD25+ Treg cell function in mice and represents a specific marker for these cells. Despite the strong association between FOXP3 expression and regulatory function in fresh human T cells, little is known about the dynamics of endogenous FOXP3 expression and its relation to the suppressive function in activated human T cells. Here, we addressed the dynamics of FOXP3 expression during human CD4+ T cell activation by plate‐bound anti‐CD3 Ab as well as the relationship between its expression and regulatory function at the single‐cell level. Our data show that FOXP3 is expressed in a high percentage of activated T cells after in vitro stimulation of human CD4+CD25– cells. FOXP3 expression is strongly associated with hyporesponsiveness of activated T cells, but is not directly correlated with their suppressive capabilities, as we demonstrate that it is also expressed in activated nonsuppressive T cells. However, in this nonsuppressive T cell population, FOXP3 expression is transient, while it is stably expressed in activated T cells that do display suppressive function, and in natural CD4+CD25++ Treg cells. These data indicate that expression of endogenous FOXP3, in humans, is not sufficient to induce regulatory T cell activity or to identify Treg cells.See accompanying commentary http://dx.doi.org/10.1002/eji.200636929
Activation of CD4+CD25+ regulatory T cell suppressor function by analogs of the selecting peptide
Authors: Larkin Joseph , Picca Cristina Cozzo , Caton Andrew J. 
Published: December 2006

AbstractCD4+CD25+Foxp3+ regulatory T (Treg) cells can undergo both thymic selection and peripheral expansion in response to self peptides that are agonists for their T cell receptors (TCR). However, the specificity by which these TCR must recognize peptide:MHC complexes to activate Treg cell function is not known. We show that CD4+CD25+Foxp3+ Treg cells can mediate suppression in response to peptides that are only weakly cross‐reactive with the self peptide that induced their formation in vivo. Moreover, suppression could be efficiently activated by peptide analogs that were inefficient at inducing CD69 up‐regulation, and that also induced little or no proliferation of naïve CD4+CD25–Foxp3– T cells expressing the same TCR. These findings provide evidence that self peptide‐specific CD4+CD25+Foxp3+ Treg cells can exert regulatory function in response to self‐ and/or pathogen‐derived peptides with which they are only weakly cross‐reactive.