bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of 8 Different NR1 Splice Variants on the Ethanol Inhibition of Recombinant NMDA Receptors
Authors: Jin Chun , Woodward John J. 
Published: March 2006

Background:N‐Methyl‐d‐aspartate (NMDA) receptors are glutamate‐activated ion channels that are assembled from NR1 and NR2 subunits. These receptors are highly enriched in brain neurons and are considered to be an important target for the acute and chronic effects of ethanol. NR2 subunits (A–D) arise from separate genes and are expressed in a developmental and brain region‐specific manner. The NR1 subunit has 8 isoforms that are generated by alternative splicing of a single gene. The heteromeric subunit makeup of the NMDA receptor determines the pharmacological and biophysical properties of the receptor and provides for functional receptor heterogeneity. Although results from previous studies suggest that NR2 subunits affect the ethanol sensitivity of NMDA receptors, the role of the NR1 subunit and its multiple splice variants is less well known.Methods:In this study, all 8 NR1 splice variants were individually coexpressed with each NR2 subunit in human embryonic kidney 293 (HEK293) cells and tested for inhibition by ethanol using patch‐clamp electrophysiology.Results:All 32 subunit combinations tested gave reproducible glutamate‐activated currents and all receptors were inhibited to some degree by 100 mM ethanol. The sensitivity of individual receptors to ethanol was affected by the specific NR1 splice variant expressed with receptors containing the NR1‐3 and NR1‐4 subunits among the least inhibited by ethanol.Conclusions:These results suggest that regional, developmental, or compensatory changes in the expression of NR1 splice variants may significantly affect ethanol inhibition of NMDA receptors.
A Pilot Study of Oxcarbazepine Versus Acamprosate in Alcohol‐Dependent Patients
Authors: Croissant Bernhard , Diehl Alexander , Klein Oliver , Zambrano Sergio , Nakovics Helmut , Heinz Andreas , Mann Karl 
Published: March 2006

Objectives: This pilot study has been designed to collect preliminary data on the use of a new antiepileptic drug in the management of alcoholic patients. Oxcarbazepine (OXC) blocks voltage‐sensitive sodium channels. Its metabolite reduces high‐voltage–activated calcium currents in striatal and cortical neurons, thus reducing glutamatergic transmission at corticostriatal synapses. This reduction is of interest in the treatment of alcohol dependence, as acamprosate (ACP) modulates NMDA receptors, resulting in an inhibition of glutamatergic transmission. Furthermore, OXC has revealed a mood‐stabilizing effect in bipolar affective disorders. We have compared OXC with ACP in relapse prevention in recently withdrawn alcohol‐dependent patients.Methods: We investigated the efficacy and safety of OXC (vs ACP) by conducting a 24‐week randomized, parallel‐group, open‐label, clinical trial on 30 acutely detoxified alcoholic patients. Survival analyses (Kaplan–Meier) were performed to look for evidence of a longer “survival” of patients receiving OXC. We assessed time to first severe relapse and additional secondary endpoints.Results: After withdrawal, time to severe relapse and time to first consumption of any ethanol by OXC patients were not longer than for ACP patients. Abstinent patients in both study groups showed a significantly lower obsessive compulsive drinking scale—German version (OCDS‐G) than relapsed patients. No undesired effects occurred when OXC patients consumed alcohol.Conclusion: Our findings indicate that it could be worthwhile to test relapse prevention using OXC in an adequate sample. While the current sample size clearly limits further conclusions from this pilot study, it is noteworthy that OXC is well tolerated, even when alcohol is on board. Thus, in medication‐based relapse prevention, OXC could be a promising alternative for alcoholic patients unable to benefit from ACP or naltrexone or those who have affective liability. OXC certainly merits a larger placebo‐controlled trial.
Pamphlets and Body‐Related Metaphors in Thomas Nashe's Pierce Penilesse and Strange Newes
Authors: Chen Chloe 
Published: March 2006

Abstract This essay was runner‐up in the 2005 Literature Compass Graduate Essay Prize, Renaissance Section. This essay explores how Thomas Nashe's Pierce Penilesse and Strange Newes describe pamphlet culture in bodily terms. Firstly, the writing of pamphlets can be understood as a type of childbirth, with the book serving as a substitute for the physical presence and the assumed voices of the author. Next, pamphlets can be considered as having to remain financially viable; if they are not, they will die. To keep the book alive, the pen must feed. Its source of food can be the rich material Nashe finds in observing fellow Londoners, or even other textual works. Nashe shows how this may be done when he performs an act of cannibalism on Gabriel Harvey's Foure Letters with his own Strange Newes. Lastly this essay compares Nashe's conception of the printing industry with Bakhtin's notion of the Rabelaisian belly as a centre of life, death, nourishment and excretion. While Nashe represents urination as a creative act, defecation becomes a metaphor for the indifferent writings sold by printers to the public. So does he regard the pamphlet industry as an ailing body which can no longer produce works of literary brilliance and intellectual substance.
In Such a State of Ink: Adolescents in the Novels of Charles Dickens
Authors: Welburn Elizabeth 
Published: March 2006

Abstract This essay won the 2005 Literature Compass Graduate Essay Prize, Victorian Section. Although Charles Dickens is known for illuminating the social issues of his time with his portrayals of children, his adolescent characters have been largely neglected by critics. Since the concept of adolescence arguably emerged for the first time in Victorian England, this article identifies the adolescents in Dickens's novels and examines their characterization in light of their historical context. In particular, this article explores Dickens's attitudes toward the political efficacy of youth and the nature of healthy personal development.
Seed Dispersal by Kerama Deer (Cervus nippon keramae) on Aka Island, the Ryukyu Archipelago, Japan1
Authors: Yamashiro Asuka , Yamashiro Tadashi 
Published: March 2006

ABSTRACTEndozoochorous seed dispersal by kerama deer (Cervus nippon keramae) was investigated at four sites on Aka Island, the Ryukyu Archipelago, Japan. Kerama deer feces contained seeds of 35 plant species. Most of the germinated seeds were small (1.3 ± 0.18 mm) and had a hard coat, comparable to the germinated seeds in several other studies of endozoochorous seed dispersal by herbivores. Both the numbers and species compositions of seeds differed among the four sites, reflecting differences in the food available to kerama deer among habitats. Although many graminoid seeds were found in the two open habitats (Sites A and B) and in the adjoining forest habitat (Site C), woody plant seeds dispersed endozoochorously by birds and mammals were dominant in the forest (Site D), away from the marsh. Although a majority of the graminoid species was growing in open habitats such as the marsh and open fields, few were growing in the forest. Therefore, the kerama deer spread many open‐habitat graminoid seeds to the open and forest habitats. If a high density of kerama deer persists for a long time and gaps in forests are created by browsing kerama deer or by other means, graminoid species may spread substantially on Aka Island. Therefore, it is possible that seed dispersal by forest deer contributes to the expansion of grasslands.
Induction of G
2
Arrest and Binding to Cyclophilin A Are Independent Phenotypes of Human Immunodeficiency Virus Type 1 Vpr
Authors: Ardon Orly , Zimmerman Erik S. , Andersen Joshua L. , DeHart Jason L. , Blackett Jana , Planelles Vicente 
Published: March 2006

ABSTRACT

Cyclophilin A (CypA) is a member of a family of cellular proteins that share a peptidyl prolyl
cis-trans
isomerase (PPIase) activity. CypA was previously reported to be required for the biochemical stability and function (specifically, induction of G
2
arrest) of the human immunodeficiency virus type 1 (HIV-1) protein R (Vpr). In the present study, we examine the role of the Vpr-CypA interaction on Vpr-induced G
2
arrest. We find that Vpr coimmunoprecipitates with CypA and that this interaction is disrupted by substitution of proline-35 of Vpr as well as incubation with the CypA inhibitor cyclosporine A (CsA). Surprisingly, the presence of CypA or its binding to Vpr is dispensable for the ability of Vpr to induce G
2
arrest. Vpr expression in CypA
−/−
cells leads to induction of G
2
arrest in a manner that is indistinguishable from that in CypA
+
cells. CsA abolished CypA-Vpr binding but had no effect on induction of G
2
arrest or Vpr steady-state levels. In view of these results, we propose that the interaction with CypA is independent of the ability of Vpr to induce cell cycle arrest. The interaction between Vpr and CypA is intriguing, and further studies should examine its potential effects on other functions of Vpr.
Systemic Immunization with an ALVAC-HIV-1/Protein Boost Vaccine Strategy Protects Rhesus Macaques from CD4+T-Cell Loss and Reduces both Systemic and Mucosal Simian-Human Immunodeficiency Virus SHIVKU2RNA Levels
Authors: Pal Ranajit , Venzon David , Santra Sampa , Kalyanaraman Vaniambadi S. , Montefiori David C. , Hocker Lindsey , Hudacik Lauren , Rose Nicolas , Nacsa Janos , Edghill-Smith Yvette , Moniuszko Marcin , Hel Zdeněk , Belyakov Igor M. , Berzofsky Jay A. , Parks Robyn Washington , Markham Phillip D. , Letvin Norman L. , Tartaglia Jim , Franchini Genoveffa 
Published: March 2006

ABSTRACTTransmission of human immunodeficiency virus type 1 (HIV-1) occurs primarily via the mucosal route, suggesting that HIV-1 vaccines may need to elicit mucosal immune responses. Here, we investigated the immunogenicity and relative efficacy of systemic immunization with two human ALVAC-HIV-1 recombinant vaccines expressing Gag, Pol, and gp120 (vCP250) or Gag, Pol, and gp160 (vCP1420) in a prime-boost protocol with their homologous vaccine native Env proteins. The relative efficacy was measured against a high-dose mucosal exposure to the pathogenic neutralization-resistant variant SHIVKU2(simian-human immunodeficiency virus). Systemic immunization with both vaccine regimens decreased viral load levels not only in blood but unexpectedly also in mucosal sites and protected macaques from peripheral CD4+T-cell loss. This protective effect was stronger when the gp120 antigen was included in the vaccine. Inclusion of recombinant Tat protein in the boosting phase along with the Env protein did not contribute further to the preservation of CD4+T cells. Thus, systemic immunization with ALVAC-HIV-1 vaccine candidates elicits anti-HIV-1 immune responses able to contain virus replication also at mucosal sites in macaques.
Vpu and Tsg101 Regulate Intracellular Targeting of the Human Immunodeficiency Virus Type 1 Core Protein Precursor Pr55

gag
Authors: Harila Kirsi , Prior Ian , Sjöberg Mathilda , Salminen Antti , Hinkula Jorma , Suomalainen Maarit 
Published: March 2006

ABSTRACT

Assembly of human immunodeficiency virus type 1 (HIV-1) is directed by the viral core protein Pr55

gag

. Depending on the cell type, Pr55

gag

accumulates either at the plasma membrane or on late endosomes/multivesicular bodies. Intracellular localization of Pr55

gag

determines the site of virus assembly, but molecular mechanisms that define cell surface or endosomal targeting of Pr55

gag

are poorly characterized. We have analyzed targeting of newly synthesized Pr55

gag

in HeLa H1 cells by pulse-chase studies and subcellular fractionations. Our results indicated that Pr55

gag

was inserted into the plasma membrane and, when coexpressed with the viral accessory protein Vpu, Pr55

gag

remained at the plasma membrane and virions assembled at this site. In contrast, Pr55

gag

expressed in the absence of Vpu was initially inserted into the plasma membrane, but subsequently endocytosed, and virus assembly was partially shifted to internal membranes. This endocytosis of Pr55

gag

required the host protein Tsg101. These results identified a previously unknown role for Vpu and Tsg101 as regulators for the endocytic uptake of Pr55

gag

and suggested that the site of HIV-1 assembly is determined by factors that regulate the endocytosis of Pr55

gag

.
Stable Association of Herpes Simplex Virus with Target Membranes Is Triggered by Low pH in the Presence of the gD Receptor, HVEM
Authors: Whitbeck J. Charles , Zuo Yi , Milne Richard S. B. , Cohen Gary H. , Eisenberg Roselyn J. 
Published: March 2006

ABSTRACT
Using a liposome-binding assay, we investigated the requirements for activation of herpes simplex virus (HSV) into a state capable of membrane interaction. Virions were mixed with liposomes along with the ectodomain of one of three gD receptors (HVEMt, nectin-1t, or nectin-2t) and incubated under different pH and temperature conditions. Virions failed to associate with liposomes in the presence of nectin-1 or nectin-2 at any temperature or pH tested. In contrast, HVEMt triggered association of HSV with liposomes at pH 5.3 or 5.0 when incubated at 37°C, suggesting that HVEM binding and mildly acidic pH at a physiological temperature provide coactivation signals, allowing virus association with membranes. Virions incubated with HVEMt at 37°C without liposomes rapidly lost infectivity upon exposure to pH 5.0, suggesting that these conditions lead to irreversible virus inactivation in the absence of target membranes. Consistent with the idea that soluble receptor molecules provide a trigger for HSV entry, HVEMt promoted virus entry into receptor-deficient CHO K1 cells. However, in B78H1 cells, HVEMt promoted virus entry with markedly lower efficiency. Interestingly, HSV entry into receptor-bearing CHO K1 cells has been shown to proceed via a pH-dependent manner, whereas HSV entry into receptor-bearing B78H1 cells is pH independent. Based on these observations, we propose that the changes triggered by HVEM and mildly acidic pH that allow liposome association are similar or identical to changes that occur during pH-dependent HSV entry.
Cap-Independent Translation Mechanism of
Red Clover Necrotic Mosaic Virus
RNA2 Differs from That of RNA1 and Is Linked to RNA Replication
Authors: Mizumoto Hiroyuki , Iwakawa Hiro-oki , Kaido Masanori , Mise Kazuyuki , Okuno Tetsuro 
Published: March 2006

ABSTRACT

The genome of
Red clover necrotic mosaic virus
(RCNMV) in the genus
Dianthovirus
is divided into two RNA molecules of RNA1 and RNA2, which have no cap structure at the 5′ end and no poly(A) tail at the 3′ end. The 3′ untranslated region (3′ UTR) of RCNMV RNA1 contains an essential RNA element (3′TE-DR1), which is required for cap-independent translation. In this study, we investigated a cap-independent translational mechanism of RNA2 using a firefly luciferase (Luc) gene expression assay system in cowpea protoplasts and a cell-free lysate (BYL) prepared from evacuolated tobacco BY2 protoplasts. We were unable to detect
cis
-acting RNA sequences in RNA2 that can replace the function of a cap structure, such as the 3′TE-DR1 of RNA1. However, the uncapped reporter RNA2, RNA2-Luc, in which the Luc open reading frame (ORF) was inserted between the 5′ UTR and the movement protein ORF, was effectively translated in the presence of p27 and p88 in protoplasts in which RNA2-Luc was replicated. Time course experiments in protoplasts showed that the translational activity of RNA2-Luc did not reflect the amount of RNA2. Mutations in
cis
-acting RNA replication elements of RNA2 abolished the cap-independent translational activity of RNA2-Luc, suggesting that the translational activity of RNA2-Luc is coupled to RNA replication. Our results show that the translational mechanism differs between two segmented genomic RNAs of RCNMV. We present a model in which only RNA2 that is generated de novo through the viral RNA replication machinery functions as mRNA for translation.
Identification of Functional Domains in Herpes Simplex Virus 2 Glycoprotein B
Authors: Li Wei , Minova-Foster Tanja J. , Norton Daniel D. , Muggeridge Martin I. 
Published: March 2006

ABSTRACT
Glycoprotein B (gB) is one of four membrane proteins that are essential for the entry of herpes simplex viruses (HSV) into cells, and coexpression of the same combination of proteins in transfected cells results in cell fusion. The latter effect is reminiscent of the ability of virus infection to cause cell fusion, particularly since the degree of fusion is greatly increased by syncytial mutations in gB. Despite intensive efforts with the gB homologs of HSV and some other herpesviruses, information about functionally important regions in the 700-amino-acid ectodomain of this protein is very limited at present. This is largely due to the misfolding of the majority of the mutants examined. It was shown previously that the percentage of correctly folded mutants could be increased by targeting only predicted loop regions (i.e., not alpha-helix or beta-strand), and by using this approach new functional domains in HSV-2 gB have now been identified.
Evidence that the Human Cytomegalovirus IE2-86 Protein Binds mdm2 and Facilitates mdm2 Degradation
Authors: Zhang Zhigang , Evers David L. , McCarville Joseph F. , Dantonel Jean-Christophe , Huong Shu-Mei , Huang Eng-Shang 
Published: March 2006

ABSTRACT
Levels of the p53 tumor suppressor protein are increased in human cytomegalovirus (HCMV)-infected cells and may be important for HCMV pathogenesis. In normal cells p53 levels are kept low due to an autoregulatory feedback loop where p53 activates the transcription of mdm2 and mdm2 binds and ubiquitinates p53, targeting p53 for proteasomal degradation. Here we report that, in contrast to uninfected cells, mdm2 was undetectable upon treatment of infected fibroblasts with the proteasome inhibitor MG132. Cellular depletion of mdm2 was reproducible in p53-null cells transfected with the HCMV IE2-86 protein, but not with IE172, independently of the endogenous mdm2 promoter. IE2-86 also prevented the emergence of presumably ubiquitinated species of p53. The regions of IE2-86 important for mdm2 depletion were those containing the sequences corresponding to the putative zinc finger and C-terminal acidic motifs. mdm2 and IE2-86 coimmunoprecipitated in transfected and infected cell lysates and in a cell-free system. IE2-86 blocked mdm2's p53-independent transactivation of the cyclin A promoter in transient-transfection experiments. Pulse-chase experiments revealed that IE2-86 but not IE1-72 or several loss-of-function IE2-86 mutants increased the half-life of p53 and reduced the half-life of mdm2. Short interfering RNA-mediated depletion of IE2-86 restored the ability of HCMV-infected cells to accumulate mdm2 in response to proteasome inhibition. Taken together, the data suggest that specific interactions between IE2-86 and mdm2 cause proteasome-independent degradation of mdm2 and that this may be important for the accumulation of p53 in HCMV-infected cells.
Characterization of Functional Domains of Equine Infectious Anemia Virus Rev Suggests a Bipartite RNA-Binding Domain
Authors: Lee Jae-Hyung , Murphy Sean C. , Belshan Michael , Sparks Wendy O. , Wannemuehler Yvonne , Liu Sijun , Hope Thomas J. , Dobbs Drena , Carpenter Susan 
Published: March 2006

ABSTRACT

Equine infectious anemia virus (EIAV) Rev is an essential regulatory protein that facilitates expression of viral mRNAs encoding structural proteins and genomic RNA and regulates alternative splicing of the bicistronic
tat/rev
mRNA. EIAV Rev is characterized by a high rate of genetic variation in vivo, and changes in Rev genotype and phenotype have been shown to coincide with changes in clinical disease. To better understand how genetic variation alters Rev phenotype, we undertook deletion and mutational analyses to map functional domains and to identify specific motifs that are essential for EIAV Rev activity. All functional domains are contained within the second exon of EIAV Rev. The overall organization of domains within Rev exon 2 includes a nuclear export signal, a large central region required for RNA binding, a nonessential region, and a C-terminal region required for both nuclear localization and RNA binding. Subcellular localization of green fluorescent protein-Rev mutants indicated that basic residues within the KRRRK motif in the C-terminal region of Rev are necessary for targeting of Rev to the nucleus. Two separate regions of Rev were necessary for RNA binding: a central region encompassing residues 57 to 130 and a C-terminal region spanning residues 144 to 165. Within these regions were two distinct, short arginine-rich motifs essential for RNA binding, including an RRDRW motif in the central region and the KRRRK motif near the C terminus. These findings suggest that EIAV Rev utilizes a bipartite RNA-binding domain.
Adaptive Evolution and Antiviral Activity of the Conserved Mammalian Cytidine Deaminase
APOBEC3H
Authors: OhAinle Molly , Kerns Julie A. , Malik Harmit S. , Emerman Michael 
Published: March 2006

ABSTRACT

The
APOBEC3
genes encode cytidine deaminases that act as components of an intrinsic immune defense that have potent activity against a variety of retroelements. This family of genes has undergone a rapid expansion from one or two genes in nonprimate mammals to at least seven members in primates. Here we describe the evolution and function of an uncharacterized antiviral effector,
APOBEC3H
, which represents the most evolutionarily divergent
APOBEC3
gene found in primates. We found that
APOBEC3H
has undergone significant adaptive evolution in primates. Consistent with our previous findings implicating adaptively evolving
APOBEC3
genes as antiviral effectors, APOBEC3H from Old World monkeys (OWMs) has efficient antiviral activity against primate lentiviruses, is sensitive to inactivation by the simian immunodeficiency virus Vif protein, and is capable of hypermutating retroviral genomes. In contrast, human APOBEC3H is inherently poorly expressed in primate cells and is ineffective at inhibiting retroviral replication. Both OWM and human APOBEC3H proteins can be expressed in bacteria, where they display significant DNA mutator activity. Thus, humans have retained an
APOBEC3H
gene that encodes a functional, but poorly expressed, cytidine deaminase with no apparent antiviral activity. The consequences of the lack of antiviral activity of human APOBEC3H are likely to be relevant to the current-day abilities of humans to combat retroviral challenges.
Inactivating a Cellular Intrinsic Immune Defense Mediated by Daxx Is the Mechanism through Which the Human Cytomegalovirus pp71 Protein Stimulates Viral Immediate-Early Gene Expression
Authors: Saffert Ryan T. , Kalejta Robert F. 
Published: March 2006

ABSTRACTHuman cytomegalovirus (HCMV) masterfully evades adaptive and innate immune responses, allowing infection to be maintained and periodically reactivated for the life of the host. Here we show that cells also possess an intrinsic immune defense against HCMV that is disarmed by the virus. In HCMV-infected cells, the promyelocytic leukemia nuclear body (PML-NB) protein Daxx silences viral immediate-early gene expression through the action of a histone deacetylase. However, this antiviral tactic is efficiently neutralized by the viral pp71 protein, which is incorporated into virions, delivered to cells upon infection, and mediates the proteasomal degradation of Daxx. This work demonstrates the mechanism through which pp71 activates viral immediate-early gene expression in HCMV-infected cells. Furthermore, it provides insight into how a PML-NB protein institutes an intrinsic immune defense against a DNA virus and how HCMV pp71 inactivates this defense.