bluuebunny/crossref_metadata_2025_split huggingface dataset:
Outcome Variables and Their Assessment in Alcohol Treatment Studies: 1968‐1998
Authors: Finney John W. , Moyer Anne , Swearingen Carolyn E. 
Published: November 2003

Background: This article provides a historical overview of the assessment of outcome variables in alcohol treatment studies that were first published between 1968 and 1998. The review focuses on changes over time in (1) the number of outcome variables and the number of different types of outcome variables assessed, (2) the likelihood of assessing specific types of outcome variables, (3) the methods used to assess outcome variables, and (4) the status of outcome assessment in more recent studies first published between 1990 and 1998.Methods: Reports of 357 alcohol treatment trials with two or more treatment/control groups were coded with respect to the number and types of outcome variables assessed, sources of outcome data, and methodological aspects of outcome assessment.Results: Although the number of outcome variables assessed in studies, on average, did not increase significantly over time, the number of different types of outcome variables did increase. An expected decrease in the assessment of categorical abstinence was not found, but another categorical variable, global ratings of drinking improvement, did decrease over time. More recent studies were more likely to assess such continuous variables as time abstinent, alcohol consumption, time drinking, dependence symptoms, and drinking‐related problems. Physiological markers of drinking/alcohol misuse also were assessed more frequently in later years. Some aspects of outcome assessment methods exhibited improvement over time; validity data were more likely to be provided or cited, and self‐reports of drinking behaviors were more likely to be corroborated in studies first published in more recent years. However, the percentages of studies that provided/cited reliability data for outcome measures, indicated that follow‐up data collectors were not affiliated with treatment and were unaware of respondents' treatment conditions, and reported that respondents were alcohol‐free at follow‐up did not rise significantly over time.Conclusions: Although the methods of outcome assessment improved between 1968 and 1998, much room for improvement remains.
Pavlovian Conditioning With Ethanol: Sign‐Tracking (Autoshaping), Conditioned Incentive, and Ethanol Self‐Administration
Authors: Krank Marvin D. 
Published: November 2003

Background: Conditioned incentive theories of addictive behavior propose that cues signaling a drug's reinforcing effects activate a central motivational state. Incentive motivation enhances drug‐taking and drug‐seeking behavior. We investigated the behavioral response to cues associated with ethanol and their interaction with operant self‐administration of ethanol.Methods: In two experiments, rats received operant training to press a lever for a sweetened ethanol solution. After operant training, the animals were given Pavlovian pairings of a brief and localized cue light with the sweetened ethanol solution (no lever present). Lever pressing for ethanol was then re‐established, and the behavioral effects of the cue light were tested during an ethanol self‐administration session.Results: The conditioned responses resulting from pairing cue lights with the opportunity to ingest ethanol had three main effects: (1) induction of operant behavior reinforced by ethanol, (2) stimulation of ethanol‐seeking behavior (magazine entries), and (3) signal‐directed behavior (i.e., autoshaping, or sign‐tracking). Signal‐directed behavior interacted with the other two effects in a manner predicted by the location of the cue light. These conditioned responses interact with operant responding for ethanol reinforcement.Conclusions: These findings demonstrate the importance of Pavlovian conditioning effects on ethanol self‐administration and are consistent with conditioned incentive theories of addictive behavior.
Effects of Ethanol on the Rat Glutamate Excitatory Amino Acid Transporter Type 3 Expressed in Xenopus Oocytes: Role of Protein Kinase C and Phosphatidylinositol 3‐Kinase
Authors: Kim Jin‐Hee , Lim Young‐Jin , Ro Young‐Jin , Min Seong‐Won , Kim Chong‐Soo , Do Sang‐Hwan , Kim Yong‐Lak , Zuo Zhiyi 
Published: November 2003

Background: Glutamate is a major excitatory neurotransmitter in the central nervous system. Glutamate transporters play a critical role in maintaining extracellular glutamate concentrations. We investigated the effects of ethanol on a neuronal glutamate transporter, excitatory amino acid transporter type 3 (EAAT3), and the role of protein kinase C (PKC) and phosphatidylinositol 3‐kinase (PI3 K) in mediating these effects.Methods: EAAT3 was expressed in Xenopus oocytes by injection of EAAT3 messenger RNA. By using a two‐electrode voltage clamp, membrane currents were recorded after the application of l‐glutamate. Responses were quantified by integration of the current trace and reported as microcoulombs. Data are mean ± SEM.Results: Ethanol enhanced EAAT3 activity in a concentration‐dependent manner. At 25, 50, 100, and 200 mM of ethanol, the responses were significantly increased compared with control values. Kinetic study demonstrated that ethanol (50 mM) significantly increased Vmax (3.48 ± 0.2 μC for control versus 4.16 ± 0.24 μC for ethanol; n= 19; p < 0.05) without a significant change in the Km (65.6 ± 11.1 μM for control versus 55.8 ± 9.6 μM for ethanol; n= 19; p > 0.05) of EAAT3 for glutamate. Preincubation of the oocytes with phorbol‐12‐myristate‐13‐acetate (PMA) significantly increased EAAT3 activity (0.98 ± 0.08 μC for control versus 1.28 ± 0.09 μC for ethanol; n= 19; p < 0.05). However, there was no statistical difference among the responses of EAAT3 to PMA, ethanol, or PMA plus ethanol. Although the PKC inhibitors chelerythrine and staurosporine did not decrease the basal EAAT3 activity, they abolished the enhancement of EAAT3 activity by ethanol. Pretreatment with wortmannin, a PI3 K inhibitor, also abolished the ethanol‐enhanced EAAT3 activity.Conclusions: These results suggest that acute ethanol exposure increases EAAT3 activity at clinically relevant concentrations and that PKC and PI3 K may be involved in mediating these ethanol effects.
Identification of Sequential Viral Escape Mutants Associated with Altered T-Cell Responses in a Human Immunodeficiency Virus Type 1-Infected Individual
Authors: Geels Mark J. , Cornelissen Marion , Schuitemaker Hanneke , Anderson Kiersten , Kwa David , Maas Jolanda , Dekker John T. , Baan Elly , Zorgdrager Fokla , van den Burg Remco , van Beelen Martijn , Lukashov Vladimir V. , Fu Tong-Ming , Paxton William A. , van der Hoek Lia , Dubey Sheri A. , Shiver John W. , Goudsmit Jaap 
Published: November 2003

ABSTRACTControl of viremia in natural human immunodeficiency virus type 1 (HIV-1) infection in humans is associated with a virus-specific T-cell response. However, still much is unknown with regard to the extent of CD8+cytotoxic T-lymphocyte (CTL) responses required to successfully control HIV-1 infection and to what extent CTL epitope escape can account for rises in viral load and ultimate progression to disease. In this study, we chose to monitor through full-length genome sequence of replication-competent biological clones the modifications that occurred within predicted CTL epitopes and to identify whether the alterations resulted in epitope escape from CTL recognition. From an extensive analysis of 59 biological HIV-1 clones generated over a period of 4 years from a single individual in whom the viral load was observed to rise, we identified the locations in the genome of five CD8+CTL epitopes. Fixed mutations were identified within the p17, gp120, gp41, Nef, and reverse transcriptase genes. Using a gamma interferon ELIspot assay, we identified for four of the five epitopes with fixed mutations a complete loss of T-cell reactivity against the wild-type epitope and a partial loss of reactivity against the mutant epitope. These results demonstrate the sequential accumulation of CTL escape in a patient during disease progression, indicating that multiple combinations of T-cell epitopes are required to control viremia.
ORF73 of Herpesvirus Saimiri Strain C488 Tethers the Viral Genome to Metaphase Chromosomes and Binds to
cis
-Acting DNA Sequences in the Terminal Repeats
Authors: Verma Subhash C. , Robertson Erle S. 
Published: November 2003

ABSTRACT

Kaposi's sarcoma (KS)-associated herpesvirus (KSHV), a human oncogenic gamma-2-herpesvirus, transforms human endothelial cells and establishes latent infection at a low efficiency in vitro. During latent infection, only a limited number of genes are expressed, and the circularized viral genome is maintained as a multicopy episome. Latency-associated nuclear antigen (LANA), exclusively expressed during latency, has been shown to have a multifunctional role in KS pathogenesis. LANA tethers the viral episome to the host chromosome, thus ensuring efficient persistence of the viral genome during successive rounds of cell division. Besides episome maintenance, LANA modulates the expression of genes of various cellular and viral pathways, including those of retinoblastoma protein and p53. Herpesvirus saimiri (HVS), another gamma-2-herpesvirus, primarily infects New World primates. Orf73, encoding the nuclear antigen of HVS, is the positional homolog of the LANA gene, and the ORF73 protein has some sequence homology to KSHV LANA. However, the function of ORF73 of HVS has not been thoroughly investigated. In this report, we show that HVS ORF73 may be important for episome persistence and colocalizes with the HVS genomic DNA on metaphase chromosomes. Furthermore, HVS terminal repeats (TRs) contain a
cis
-acting sequence similar to that in KSHV TRs, suggesting that the LANA binding sequence is conserved between these two viruses. This
cis
-acting element is sufficient to bind HVS ORF73 from strains C488 and A11, and plasmids containing the HVS C488 TR element are maintained and replicate in HVS C488 ORF73-expressing cells.
Role for Influenza Virus Envelope Cholesterol in Virus Entry and Infection
Authors: Sun Xiangjie , Whittaker Gary R. 
Published: November 2003

ABSTRACT
Enveloped viruses are highly dependent on their lipid envelopes for entry into and infection of host cells. Here, we have examined the role of cholesterol in the virus envelope, using methyl-β-cyclodextrin depletion. Pretreatment of virions with methyl-β-cyclodextrin efficiently depleted envelope cholesterol from influenza virus and significantly reduced virus infectivity in a dose-dependent manner. A nonenveloped virus, simian virus 40, was not affected by methyl-β-cyclodextrin treatment. In the case of influenza virus, infectivity could be partially rescued by the addition of exogenous cholesterol. Influenza virus morphology, binding, and internalization were not affected by methyl-β-cyclodextrin depletion, whereas envelope cholesterol depletion markedly affected influenza virus fusion, as measured by a specific reduction in the infectivity of viruses induced to fuse at the cell surface and by fluorescence-dequenching assays. These data suggest that envelope cholesterol is a critical factor in the fusion process of influenza virus.
Human Immunodeficiency Virus Type 1 N-Terminal Capsid Mutants Containing Cores with Abnormally High Levels of Capsid Protein and Virtually No Reverse Transcriptase
Authors: Tang Shixing , Murakami Tsutomu , Cheng Naiqian , Steven Alasdair C. , Freed Eric O. , Levin Judith G. 
Published: November 2003

ABSTRACT
We previously described the phenotype associated with three alanine substitution mutations in conserved residues (Trp23, Phe40, and Asp51) in the N-terminal domain of human immunodeficiency virus type 1 capsid protein (CA). All of the mutants produce noninfectious virions that lack conical cores and, despite having a functional reverse transcriptase (RT), are unable to initiate reverse transcription in vivo. Here, we have focused on elucidating the mechanism by which these CA mutations disrupt virus infectivity. We also report that cyclophilin A packaging is severely reduced in W23A and F40A virions, even though these residues are distant from the cyclophilin A binding loop. To correlate loss of infectivity with a possible defect in an early event preceding reverse transcription, we modeled disassembly by generating viral cores from particles treated with mild nonionic detergent; cores were isolated by sedimentation in sucrose density gradients. In general, fractions containing mutant cores exhibited a normal protein profile. However, there were two striking differences from the wild-type pattern: mutant core fractions displayed a marked deficiency in RT protein and enzymatic activity (<5% of total RT in gradient fractions) and a substantial increase in the retention of CA. The high level of core-associated CA suggests that mutant cores may be unable to undergo proper disassembly. Thus, taken together with the almost complete absence of RT in mutant cores, these findings can account for the failure of the three CA mutants to synthesize viral DNA following virus entry into cells.
Human Immunodeficiency Virus Type 1 Infection Inhibits Granulocyte-Macrophage Colony-Stimulating Factor-Induced Activation of STAT5A in Human Monocyte-Derived Macrophages
Authors: Warby Tammra J. , Crowe Suzanne M. , Jaworowski Anthony 
Published: November 2003

ABSTRACTHuman immunodeficiency virus type 1 (HIV-1) infects cells of the monocyte/macrophage lineage. While infection of macrophages by HIV-1 is generally not cytopathic, it does impair macrophage function. In this study, we examined the effect of HIV-1 infection on intracellular signaling in human monocyte-derived macrophages (MDM) stimulated with the growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF). GM-CSF is an important growth factor for cells of both the macrophage and granulocyte lineages and enhances effector functions of these cells via the heterodimeric GM-CSF receptor (GM-CSFR). A major pathway which mediates the effects of GM-CSF on macrophages involves activation of the latent transcription factor STAT5A via a Janus kinase 2 (JAK2)-dependent pathway. We demonstrate that GM-CSF-induced activation of STAT5A is inhibited in MDM after infection in vitro with the laboratory-adapted R5 strain of HIV-1, HIV-1Ba-L, but not after infection with adenovirus. HIV-1 infection of MDM did not decrease the STAT5A or JAK2 mRNA level or STAT5A protein level or result in increased constitutive activation of STAT5A. Surface expression of either the α-chain or common βc-chain of GM-CSFR was also unaffected. We conclude that HIV-1 inhibits GM-CSF activation of STAT5A without affecting expression of the known components of the signaling pathway. These data provide further evidence of disruption of cellular signaling pathways after HIV-1 infection, which may contribute to immune dysfunction and HIV-1 pathogenesis.
Functional Interaction between the Herpes Simplex Virus Type 1 Polymerase Processivity Factor and Origin-Binding Proteins: Enhancement of UL9 Helicase Activity
Authors: Trego Kelly S. , Parris Deborah S. 
Published: November 2003

ABSTRACT
The origin (ori)-binding protein of herpes simplex virus type 1 (HSV-1), encoded by the UL9 open reading frame, has been shown to physically interact with a number of cellular and viral proteins, including three HSV-1 proteins (ICP8, UL42, and UL8) essential for ori-dependent DNA replication. In this report, it is demonstrated for the first time that the DNA polymerase processivity factor, UL42 protein, provides accessory function to the UL9 protein by enhancing the 3′-to-5′ helicase activity of UL9 on partially duplex nonspecific DNA substrates. UL42 fails to enhance the unwinding activity of a noncognate helicase, suggesting that enhancement of unwinding requires the physical interaction between UL42 and UL9. UL42 increases the steady-state rate for unwinding a 23/38-mer by UL9, but only at limiting UL9 concentrations, consistent with a role in increasing the affinity of UL9 for DNA. Optimum enhancement of unwinding was observed at UL42/UL9 molecular ratios of 4:1, although enhancement was reduced when high UL42/DNA ratios were present. Under the assay conditions employed, UL42 did not alter the rate constant for dissociation of UL9 from the DNA substrate. UL42 also did not significantly reduce the lag period which was observed following the addition of UL9 to DNA, regardless of whether UL42 was added to DNA prior to or at the same time as UL9. Moreover, addition of UL42 to ongoing unwinding reactions increased the steady-state rate for unwinding, but only after a 10- to 15-min lag period. Thus, the increased affinity of UL9 for DNA most likely is the result of an increase in the rate constant for binding of UL9 to DNA, and it explains why helicase enhancement is observed only at subsaturating concentrations of UL9 with respect to DNA. In contrast, ICP8 enhances unwinding at both saturating and subsaturating UL9 concentrations and reduces or eliminates the lag period. The different means by which ICP8 and UL42 enhance the ability of UL9 to unwind DNA suggest that these two members of the presumed functional replisome may act synergistically on UL9 to effect initiation of HSV-1 DNA replication in vivo.
Convergence of RNA
cis
Elements and Cellular Polyadenylation Factors in the Regulation of Human Cytomegalovirus UL37 Exon 1 Unspliced RNA Production
Authors: Su Yan , Adair Richard , Davis Candice N. , DiFronzo Nancy L. , Colberg-Poley Anamaris M. 
Published: November 2003

ABSTRACT

The human cytomegalovirus (HCMV) UL36-38 immediate early (IE) locus encodes proteins required for its growth. The UL37 promoter drives production of an unspliced and several alternatively spliced RNAs. The UL37 exon 1 (UL37x1) unspliced RNA is abundant from IE to late times of HCMV infection, whereas the UL37 spliced RNAs are markedly less abundant. Production of the UL37x1 unspliced RNA requires polyadenylation (PA) at nucleotide 50998, which lies within intron 1, upstream of the UL37 exon 2 (UL37x2) acceptor. The physical proximity of its
cis
elements suggests steric hindrance between PA and splicing machineries for UL37 pre-mRNA. To test this possibility, we generated site-specific mutants in Target 1 PA and RNA splicing
cis
elements and compared the PA and splicing efficiencies of mutant RNAs with those of wild-type RNA. The mutually exclusive processing events of UL37x1 PA and UL37x1-UL37x2 splicing have been accurately recapitulated in transfected permissive human fibroblasts (HFFs) expressing a Target 1 minigene RNA, which contains the required splicing and PA
cis
elements. Two mutants in the invariant PA signal dramatically decreased UL37x1 PA as expected and, concomitantly, increased the efficiency of UL37x1-UL37x2 RNA splicing. Consistent with these results, changes to consensus UL37x1 donor and UL37x2 acceptor sites increased the efficiency of UL37x1-UL37x2 RNA splicing but decreased the efficiency of UL37x1 PA. Moreover, HCMV infection of HFFs increased the abundance of the PA cleavage stimulatory factor CstF-64, the potent splicing suppressor PTB, and the hypophosphorylated form of the splicing factor SF2 at 4 h postinfection. Induction of these factors further favors production of the UL37x1 unspliced RNA over that of the spliced RNAs. Taken together, these results suggest that there is a convergence in UL37 RNA regulation by
cis
elements and cellular proteins which favors production of the UL37x1 unspliced RNA during HCMV infection at the posttranscriptional level.
Replication-Defective Adenoviral Vaccine Vector for the Induction of Immune Responses to Dengue Virus Type 2
Authors: Jaiswal Smita , Khanna Navin , Swaminathan S. 
Published: November 2003

ABSTRACT
A recombinant replication-defective adenovirus vector that can overexpress the ectodomain of the envelope protein of dengue virus type 2 (NGC strain) has been constructed. This virus was immunogenic in mice and elicited dengue virus type 2 specific B- and T-cell responses. Sera from immunized mice contained neutralizing antibodies that could specifically recognize dengue virus type 2 and neutralize its infectivity in vitro, indicating that this approach has the potential to confer protective immunity. In vitro stimulation of splenocytes (from immunized mice) with dengue virus type 2 resulted in a significant proliferative response accompanied by the production of high levels of gamma interferon but did not show significant changes in interleukin-4 levels. This is suggestive of a Th1-like response (considered to be important in the maturation of cytotoxic T lymphocytes that are essential for the elimination of virus-infected cells). The data show that adenovirus vectors offer a promising alternative strategy for the development of dengue virus vaccines.
Anti-Human Immunodeficiency Virus Activity of Tau Interferon in Human Macrophages: Involvement of Cellular Factors and β-Chemokines
Authors: Rogez Christine , Martin Marc , Dereuddre-Bosquet Nathalie , Martal Jacques , Dormont Dominique , Clayette Pascal 
Published: November 2003

ABSTRACTTau interferon (IFN-τ) is a noncytotoxic type I IFN responsible for maternal recognition of the fetus in ruminants. IFN-τ inhibits human immunodeficiency virus (HIV) replication more strongly than human IFN-α, particularly in human monocyte-derived macrophages. In this study performed in human macrophages, IFN-τ efficiently inhibited the early steps of the biological cycle of HIV, decreasing intracellular HIV RNA and inhibiting the initiation of the reverse transcription of viral RNA into proviral DNA. Two mechanisms induced by IFN-τ treatment in macrophages may account for this inhibition: (i) the synthesis of the cellular antiviral factors such as 2′,5′-oligoadenylate synthetase/RNase L and MxA protein and (ii) an increased production of MIP-1α, MIP-1β, and RANTES, which are natural ligands of CCR5, the principal coreceptor of HIV on macrophages. Our results suggest that IFN-τ induces the same antiviral pathways in macrophages as other type I IFNs but without associated toxicity.
Hypo-osmotic or Ca2+-rich external conditions trigger extra contractile vacuole complex generation inParamecium multimicronucleatum
Authors: Iwamoto Masaaki , Allen Richard D. , Naitoh Yutaka 
Published: November 2003

SUMMARYThe freshwater ciliated protozoan, Paramecium multimicronucleatum,usually possesses two contractile vacuole complexes (CVCs). The number of CVCs in a single cell, however, may vary from 1 to 7. We found that the number of cells that have more than two CVCs increased after the cells were exposed to a hypo-osmotic or a high Ca2+ condition. It is assumed that the biological significance of this increase in the number of CVCs is to enhance the cell's ability to eliminate excess water or Ca2+ from the cytosol. An extra CVC was either generated de novo in the posterior region of the cell or, when in the anterior region, by binary fission of the anterior CVC. Generation of these extra CVCs was not inhibited by aphidicolin,a potent inhibitor of DNA synthesis in the micronuclei of Paramecium,even though normal duplication of the CVC that accompanies normal cell division was completely inhibited by this inhibitor. These results suggest that generation of extra CVCs is controlled by a hypothetical regulatory mechanism that is activated either by a hypo-osmotic or by a Ca2+-rich condition and that differs from the regulatory mechanism that governs normal CVC duplication during cell division.