872 resultados para Hymns, Welsh.
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Wnt family members are critical to many developmental processes, and components of the Wnt signaling pathway have been linked to tumorigenesis in familial and sporadic colon carcinomas. Here we report the identification of two genes, WISP-1 and WISP-2, that are up-regulated in the mouse mammary epithelial cell line C57MG transformed by Wnt-1, but not by Wnt-4. Together with a third related gene, WISP-3, these proteins define a subfamily of the connective tissue growth factor family. Two distinct systems demonstrated WISP induction to be associated with the expression of Wnt-1. These included (i) C57MG cells infected with a Wnt-1 retroviral vector or expressing Wnt-1 under the control of a tetracyline repressible promoter, and (ii) Wnt-1 transgenic mice. The WISP-1 gene was localized to human chromosome 8q24.1–8q24.3. WISP-1 genomic DNA was amplified in colon cancer cell lines and in human colon tumors and its RNA overexpressed (2- to >30-fold) in 84% of the tumors examined compared with patient-matched normal mucosa. WISP-3 mapped to chromosome 6q22–6q23 and also was overexpressed (4- to >40-fold) in 63% of the colon tumors analyzed. In contrast, WISP-2 mapped to human chromosome 20q12–20q13 and its DNA was amplified, but RNA expression was reduced (2- to >30-fold) in 79% of the tumors. These results suggest that the WISP genes may be downstream of Wnt-1 signaling and that aberrant levels of WISP expression in colon cancer may play a role in colon tumorigenesis.
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Human β-defensins (HBDs) are antimicrobial peptides that may play a role in mucosal defense. Diminished activity of these peptides has been implicated in the pathogenesis of cystic fibrosis (CF) lung disease. We show that HBD-1 and HBD-2 mRNAs are expressed in excised surface and submucosal gland epithelia from non-CF and CF patients. The pro-inflammatory cytokine interleukin-1β stimulated the expression of HBD-2 but not HBD-1 mRNA and peptide in primary cultures of airway epithelia. HBD-1 was found in bronchoalveolar lavage (BAL) fluid from normal volunteers, CF patients, and patients with inflammatory lung diseases, whereas HBD-2 was detected in BAL fluid from patients with CF or inflammatory lung diseases, but not in normal volunteers. Both HBD-1 and HBD-2 were found in BAL fluid in concentrations of several ng/ml, and both recombinant peptides showed salt-sensitive bactericidal activity. These data suggest that in the lung HBD-2 expression is induced by inflammation, whereas HBD-1 may serve as a defense in the absence of inflammation.
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Phosphorylation of the regulatory (R) domain initiates cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel activity. To discover how the function of this domain is determined by its structure, we produced an R domain protein (R8) that spanned residues 708–831 of CFTR. Phosphorylated, but not unphosphorylated, R8 stimulated activity of CFTR channels lacking this domain, indicating that R8 is functional. Unexpectedly, this functional R8 was predominantly random coil, as revealed by CD and limited proteolysis. The CD spectra of both phosphorylated and nonphosphorylated R8 were similar in aqueous buffer. The folding agent trimethylamine N-oxide induced only a small increase in the helical content of nonphosphorylated R8 and even less change in the helical content of phosphorylated R8. These data, indicating that the R domain is predominantly random coil, may explain the seemingly complex way in which phosphorylation regulates CFTR channel activity.
Resumo:
Opening and closing of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel is regulated by the interaction of ATP with its two cytoplasmic nucleotide-binding domains (NBD). Although ATP hydrolysis by the NBDs is required for normal gating, the influence of ATP binding versus hydrolysis on specific steps in the gating cycle remains uncertain. Earlier work showed that the absence of Mg2+ prevents hydrolysis. We found that even in the absence of Mg2+, ATP could support channel activity, albeit at a reduced level compared with the presence of Mg2+. Application of ATP with a divalent cation, including the poorly hydrolyzed CaATP complex, increased the rate of opening. Moreover, in CFTR variants with mutations that disrupt hydrolysis, ATP alone opened the channel and Mg2+ further enhanced ATP-dependent opening. These data suggest that ATP alone can open the channel and that divalent cations increase ATP binding. Consistent with this conclusion, when we mutated an aspartate thought to bind Mg2+, divalent cations failed to increase activity compared with ATP alone. Two observations suggested that divalent cations also stabilize the open state. In wild-type CFTR, CaATP generated a long duration open state, whereas ATP alone did not. With a CFTR variant in which hydrolysis was disrupted, MgATP, but not ATP alone, produced long openings. These results suggest a gating cycle for CFTR in which ATP binding opens the channel and either hydrolysis or dissociation leads to channel closure. In addition, the data suggest that ATP binding and hydrolysis by either NBD can gate the channel.
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Two different attentional networks have been associated with visuospatial attention and conflict resolution. In most situations either one of the two networks is active or both are increased in activity together. By using functional magnetic resonance imaging and a flanker task, we show conditions in which one network (anterior attention system) is increased in activity whereas the other (visuospatial attention system) is reduced, showing that attentional conflict and selection are separate aspects of attention. Further, we distinguish between neural systems involved in different forms of conflict. Specifically, we dissociate patterns of activity in the basal ganglia and insula cortex during simple violations in expectancies (i.e., sudden changes in the frequency of an event) from patterns of activity in the anterior attention system specifically correlated with response conflict as evidenced by longer response latencies and more errors. These data provide a systems-level approach in understanding integrated attentional networks.
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Tumor necrosis factor receptors (TNFR) are single transmembrane-spanning glycoproteins that bind cytokines and trigger multiple signal transduction pathways. Many of these TNFRs rely on interactions with TRAF proteins that bind to the intracellular domain of the receptors. CD40 is a member of the TNFR family that binds to several different TRAF proteins. We have determined the crystal structure of a 20-residue fragment from the cytoplasmic domain of CD40 in complex with the TRAF domain of TRAF3. The CD40 fragment binds as a hairpin loop across the surface of the TRAF domain. Residues shown by mutagenesis and deletion analysis to be critical for TRAF3 binding are involved either in direct contact with TRAF3 or in intramolecular interactions that stabilize the hairpin. Comparison of the interactions of CD40 with TRAF3 vs. TRAF2 suggests that CD40 may assume different conformations when bound to different TRAF family members. This molecular adaptation may influence binding affinity and specific cellular triggers.
Resumo:
ATP-binding cassette (ABC) transporters bind and hydrolyze ATP. In the cystic fibrosis transmembrane conductance regulator Cl− channel, this interaction with ATP generates a gating cycle between a closed (C) and two open (O1 and O2) conformations. To understand better how ATP controls channel activity, we examined gating transitions from the C to the O1 and O2 states and from these open states to the C conformation. We made three main observations. First, we found that the channel can open into either the O1 or O2 state, that the frequency of transitions to both states was increased by ATP concentration, and that ATP increased the relative proportion of openings into O1 vs. O2. These results indicate that ATP can interact with the closed state to open the channel in at least two ways, which may involve binding to nucleotide-binding domains (NBDs) NBD1 and NBD2. Second, ATP prolonged the burst duration and altered the way in which the channel closed. These data suggest that ATP also interacts with the open channel. Third, the channel showed runs of specific types of open–closed transitions. This finding suggests a mechanism with more than one cycle of gating transitions. These data suggest models to explain how ATP influences conformational transitions in cystic fibrosis transmembrane conductance regulator and perhaps other ABC transporters.
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Several DEG/ENaC cation channel subunits are expressed in the tongue and in cutaneous sensory neurons, where they are postulated to function as receptors for salt and sour taste and for touch. Because these tissues are exposed to large temperature variations, we examined how temperature affects DEG/ENaC channel function. We found that cold temperature markedly increased the constitutively active Na+ currents generated by epithelial Na+ channels (ENaC). Half-maximal stimulation occurred at 25°C. Cold temperature did not induce current from other DEG/ENaC family members (BNC1, ASIC, and DRASIC). However, when these channels were activated by acid, cold temperature potentiated the currents by slowing the rate of desensitization. Potentiation was abolished by a “Deg” mutation that alters channel gating. Temperature changes in the physiologic range had prominent effects on current in cells heterologously expressing acid-gated DEG/ENaC channels, as well as in dorsal root ganglion sensory neurons. The finding that cold temperature modulates DEG/ENaC channel function may provide a molecular explanation for the widely recognized ability of temperature to modify taste sensation and mechanosensation.
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We have analyzed the developmental molecular programs of the mouse hippocampus, a cortical structure critical for learning and memory, by means of large-scale DNA microarray techniques. Of 11,000 genes and expressed sequence tags examined, 1,926 showed dynamic changes during hippocampal development from embryonic day 16 to postnatal day 30. Gene-cluster analysis was used to group these genes into 16 distinct clusters with striking patterns that appear to correlate with major developmental hallmarks and cellular events. These include genes involved in neuronal proliferation, differentiation, and synapse formation. A complete list of the transcriptional changes has been compiled into a comprehensive gene profile database (http://BrainGenomics.Princeton.edu), which should prove valuable in advancing our understanding of the molecular and genetic programs underlying both the development and the functions of the mammalian brain.
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Este artículo se centra en el análisis de la tipología, características y evolución de algunos de los diversos rituales de movilización y símbolos desplegados en el espacio público por las distintas organizaciones y núcleos de militantes de signo confederal y anarquista en España durante los años de la Segunda República, antes del estallido de la sublevación militar de julio de 1936. Entre ellos: huelgas, insurrecciones revolucionarias, mítines, manifestaciones, excursiones, entierros de militantes, etc. El propósito de estas acciones era claro: tanto la cohesión y reafirmación identitaria internas, como la proyección externa del movimiento. Con estas estrategias de acción colectiva, que suponían una “salida” al espacio público, se trataba de hacer visible allí la fuerza del movimiento y reafirmar la presencia física de este, sus reivindicaciones y aspiraciones. Esta visibilidad se reforzaba mediante el despliegue de los símbolos propios: himnos, canciones, banderas, etc.
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Written by unidentified scribe in Church Slavic of Serbian recension, in semiuncial book hand in brown ink on vellum, headings and initials in red ink; front pages are missing; pagination in pencil starts on f. 1.
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This volume contains a fair copy of minutes from Corporation meetings held from May 5, 1778 through October 14, 1803. It begins with an alphabetical index and contains entries related to a wide range of topics, including changes in the College laws; lists of Harvard graduates; historical information about the College and its governance; memorials to the Massachusetts General Court about currency concerns, the West Boston Bridge, and other matters; the establishment of medical professorships and selection of professors to fill them; land and property belonging to Harvard; the settlement of accounts with former College Treasurer John Hancock; support of missionaries to several Indian tribes; the establishment of a student dress code; the Charlestown Ferry, and its revenue troubles following the construction of the West Boston Bridge; the purchase of a wooden sloop for transporting students' "fuel" (presumably firewood); the creation and distribution of library catalogs; the commission of a lucernal microscope for the College Apparatus; Oneida Indian Isaac Solegwaston and Harvard's financial support of his studies at the Hamilton Oneida Academy; transcriptions of a letter (October 23, 1789) from the Corporation to President George Washington and of Washington's response; a petition to the General Court for the establishment of a public infirmary to serve the indigent; individuals who were granted permission to instruct Harvard students in the French language outside the established curriculum; and Thomas Welsh's excused absence from his Harvard graduation, granted June 14, 1798, because of his imminent departure for Berlin to serve as Secretary to John Quincy Adams, then Minister Plenipotentiary to Berlin.
Resumo:
John Pierce kept this journal while he was a student at Harvard College. It consists of manuscript musical scores with annotations indicating the occasions at which the music was performed. These occasions included commencements, public exhibitions and Dudleian lectures. A note indicates that one anthem was prepared by Samuel Holyoke at Pierce's request, to be performed at Pierce's class commencement exercises, held on July 13, 1793. Several annotations were made in May 1794, the year following Pierce's graduation. There is a table of contents on the last page.
Resumo:
By Thomas Walter, M.A. ; Recommended by several ministers. ; [One line from Psalms]
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Contains entries on a variety of topics arranged alphabetically and compiled by several individuals. Includes an index at the end.