bluuebunny/crossref_metadata_2025_split huggingface dataset:
Binding of Acetaldehyde to a Glutathione Metabolite: Mass Spectrometric Characterization of an Acetaldehyde‐Cysteinylglycine Conjugate
Authors: Anni Helen , Pristatsky Pavlo , Israel Yedy 
Published: November 2003

Background: Ethanol administration decreases hepatic glutathione levels and increases urinary sulfhydryl excretion. Ethanol‐induced liver injury is blunted by the administration of glutathione precursors. Acetaldehyde generated in the metabolism of ethanol binds to a number of amino acid residues in proteins and peptides, but it does not react readily with glutathione. Due to the possible role of acetaldehyde in cysteine and glutathione homeostasis, we investigated the reaction of acetaldehyde to cysteinylglycine, the dipeptide generated in vivo in the hydrolysis of glutathione by γ‐glutamyltransferase.Methods: A conjugate between acetaldehyde and cysteinylglycine was generated under physiologically relevant conditions, both in vitro and in vivo. It was separated by a new reverse‐phase high‐performance liquid chromatography method and identified by electrospray ionization/ion trap tandem mass spectrometric analysis.Results: The conjugate with a stoichiometry of 1:1 between cysteinylglycine and acetaldehyde is most rapidly generated in vitro and was identified by mass spectroscopy as 2‐methyl‐thiazolidine‐4‐carbonyl‐glycine. This thiazolidine derivative is stable in vitro and in biological fluids of rats. The conjugate was present in high concentrations in the bile of rats pretreated with ethanol and an inhibitor of aldehyde dehydrogenase.Conclusions: The sequestering of cysteinylglycine by acetaldehyde occurs rapidly under physiologic conditions. Long‐lived sulfur‐containing biomolecules that incorporate acetaldehyde might affect cysteine and glutathione homeostasis and may also play a protective role by reducing circulating acetaldehyde levels. The acetaldehyde conjugate or its metabolic products could potentially serve as markers of ethanol consumption.
Reverse Selection for Differential Response to the Locomotor Stimulant Effects of Ethanol Provides Evidence for Pleiotropic Genetic Influence on Locomotor Response to Other Drugs of Abuse
Authors: Bergstrom Hadley C. , Palmer Abraham A. , Wood Robin D. , Burkhart‐Kasch Sue , McKinnon Carrie S. , Phillips Tamara J. 
Published: November 2003

Background: Addictive drugs share the ability to induce euphoria, which may be associated with their potential for abuse. Replicate mouse lines with high (FAST‐1, FAST‐2) and low (SLOW‐1, SLOW‐2) sensitivity to ethanol‐induced psychomotor stimulation (a possible animal model for the euphoria experienced by humans) have provided evidence for common genetic influences (pleiotropy) on sensitivity to the effects of ethanol and of GABA‐A receptor acting compounds on locomotor activity. Differences between FAST and SLOW mice in locomotor response to certain other drugs were found later in selection. Reverse selection produced lines (r‐FAST‐1, r‐FAST‐2, r‐SLOW‐1, r‐SLOW‐2) with similar locomotor responses to ethanol. These lines are well suited for asking whether the same alleles that influence sensitivity to ethanol are also responsible for these later arising differences in drug sensitivity.Methods: Two replicate sets of forward‐ and reverse‐selected FAST and SLOW lines were tested for the effects of multiple doses of morphine, cocaine, methamphetamine, nicotine, and scopolamine on their locomotor behavior. We predicted that differences in drug sensitivity between the FAST and SLOW lines would be reduced or eliminated in the reverse‐selected lines.Results: Differences in sensitivity to morphine, cocaine, methamphetamine, and nicotine that arose in earlier generations of the FAST‐1 and SLOW‐1 lines ultimately also appeared in the FAST‐2 and SLOW‐2 lines. However, some differences between the FAST‐2 and SLOW‐2 lines (those in response to cocaine and methamphetamine) were not seen until several generations after selection had been relaxed. In lines reverse‐selected for sensitivity to ethanol, differences in sensitivity to the other drugs were decreased, eliminated, or even reversed. No differences in scopolamine response were found in the replicate 1 forward‐ or reverse‐selected lines. However, a small difference in scopolamine response in the replicate 2 lines was reversed.Conclusions: Genes that influence the locomotor response to ethanol also influence locomotor response to other drugs with stimulant effects in the FAST and SLOW mice. The current data most strongly support this conclusion for sensitivity to morphine and nicotine.
Assessing Drinking Outcomes in Alcohol Treatment Efficacy Studies: Selecting a Yardstick of Success
Authors: Sobell Linda Carter , Sobell Mark B. , Connors Gerard J. , Agrawal Sangeeta 
Published: November 2003

Background: Although the number of alcohol treatment efficacy trials has mushroomed, there is no consensus on how best to measure outcomes. To advance the goal of establishing cross‐trial consistency in measuring outcomes in clinical efficacy studies, the National Institute on Alcohol Abuse and Alcoholism convened a panel of experts and charged them with exploring, debating, and, ultimately, selecting a “sentinel” or “optimal” outcome measure to be used in future alcohol treatment studies. The goal of this article, one in a series of several presented at the National Institute on Alcohol Abuse and Alcoholism conference, is to discuss (1) the rationale underlying selection of an optimal outcome measure, (2) the necessary characteristics of an optimal outcome measure, (3) the utility of selecting an optimal measure, and (4) which drinking assessment methods could be used to collect data to portray the optimal outcome measure.Methods: At a minimum, the criteria for an “optimal” measure include that it be psychometrically sound. In addition, it should have considerable currency in the field, thereby increasing its prospects for adoption. The measure should also be consistent with the concepts of greatest interest and relevance to the field (e.g., directly reflect the fundamental goal of alcohol treatment). In light of these highly desired features, percent of days heavy drinking was chosen at the conference as a practical and relevant measure of alcohol treatment outcome.Conclusions: Percent of days heavy drinking should be the optimal measure of alcohol treatment outcome. Currently, daily drinking estimation methods are the most useful for gathering data that can reflect the optimal measure. In addition, data gathered by daily drinking estimation methods can be used to study a variety of other outcome variables of interest to clinical researchers.
Clinical and Methodological Utility of a Composite Outcome Measure for Alcohol Treatment Research
Authors: Zweben Allen , Cisler Ron A. 
Published: November 2003

Background: How to capture different response patterns resulting from alcohol treatment has been a troublesome issue for alcohol researchers. A composite measure is one approach to capturing multiple treatment outcomes among diverse client populations. This article provides the rationale, development, and work conducted thus far on the composite outcome index and discusses the clinical utility of the measure.Methods: With the use of Project MATCH data, the composite outcome measure was examined in relation to self‐reported alcohol consumption and alcohol problems and biological markers as well as in relation to other areas of functioning, such as psychiatric dysfunction and quality of life. Also, for assessing the stability of the measure, different composite outcomes statuses were assessed over time.Results: Individuals with better scores on composite outcome index had fewer percent days abstinent, consumed more alcohol when they drank, had a greater number of alcohol problems, and evidenced higher blood levels as measured by γ‐glutamyltranspeptidase and carbohydrate‐deficient transferrin. Individuals with poorer composite outcome statuses had poorer social and behavioral role functioning and mental and physical health–related quality of life. Findings on short‐ and long‐term composite outcome statuses revealed that only a minority of clients (30%) sustained a remitted status (i.e., abstinent or moderate drinking without problems) over the 1‐year follow‐up, and fully 70% of the clients had reached a nonremitted status (i.e., heavy drinking and/or problems) on the composite measure at one or more time points during the 12‐month follow‐up.Conclusions: The composite outcome index could be used usefully along with singular measures of consumption to obtain a more complete picture of what has occurred among clients posttreatment. Future work will involve the testing of the composite outcome index with other client populations and/or different treatments to further our understanding of the varying response patterns found among alcohol‐dependent clients.
Distinct Regions of the slo Subunit Determine Differential BKCa Channel Responses to Ethanol
Authors: Liu Pengchong , Liu Jianxi , Huang Weihua , Li Ming D. , Dopico Alejandro M. 
Published: November 2003

Background: Ethanol at clinically relevant concentrations increases BKCa channel activity in dorsal root ganglia neurons, GH3 cells, and neurohypophysial terminals, leading to decreases in cell excitability and peptide release. In contrast, ethanol inhibits BKCa channels from aortic myocytes, which likely contributes to alcohol‐induced aortic constriction. The mechanisms that determine differential BKCa channel responses to ethanol are unknown. We hypothesized that nonconserved regions in the BKCa channel‐forming subunit (slo) are major contributors to the differential alcohol responses of different BKCa channel phenotypes.Methods: We constructed chimeras by interchanging the core and the tail domains of two BKCa channel‐forming subunits (mslo and bslo) that, after expression, differentially respond to ethanol (activation and inhibition, respectively), and studied ethanol action on these mbslo and bmslo chimeric channels using single‐channel, patch‐clamp techniques.Results and Conclusion: Data from cell‐free membranes patches demonstrate that the activity of channels that share a mslo‐type core‐linker (wt mslo and the mbslo chimera) is consistently and significantly potentiated by acute exposure to ethanol. Thus, a mslo tail is not necessary for ethanol potentiation of slo channels. In contrast, the activity of channels that share a bslo‐type core‐linker (wt bslo and the bmslo chimera) display heterogenous responses to ethanol: inhibition (in the majority of cases), refractoriness, or activation. Overall, our data indicate that the slo core‐linker is a critical region likely contributing to the differential responses of BKCa channels to ethanol.
The Eukaryotic Translation Initiation Factor 4GI Is Cleaved by Different Retroviral Proteases
Authors: Álvarez Enrique , Menéndez-Arias Luis , Carrasco Luis 
Published: November 2003

ABSTRACT

The initiation factor eIF4G plays a central role in the regulation of translation. In picornaviruses, as well as in human immunodeficiency virus type 1 (HIV-1), cleavage of eIF4G by the viral protease leads to inhibition of protein synthesis directed by capped cellular mRNAs. In the present work, cleavage of both eIF4GI and eIF4GII has been analyzed by employing the proteases encoded within the genomes of several members of the family
Retroviridae
, e.g., Moloney murine leukemia virus (MoMLV), mouse mammary tumor virus, human T-cell leukemia virus type 1, HIV-2, and simian immunodeficiency virus. All of the retroviral proteases examined were able to cleave the initiation factor eIF4GI both in intact cells and in cell-free systems, albeit with different efficiencies. The eIF4GI hydrolysis patterns obtained with HIV-1 and HIV-2 proteases were very similar to each other but rather different from those obtained with MoMLV protease. Both eIF4GI and eIF4GII were cleaved very efficiently by the MoMLV protease. However, eIF4GII was a poor substrate for HIV proteases. Proteolytic cleavage of eIF4G led to a profound inhibition of cap-dependent translation, while protein synthesis driven by mRNAs containing internal ribosome entry site elements remained unaffected or was even stimulated in transfected cells.
Transgenic Mouse with the Herpes Simplex Virus Type 1 Latency-Associated Gene: Expression and Function of the Transgene
Authors: Mador Nurith , Braun Efrat , Haim Hillel , Ariel Ilana , Panet Amos , Steiner Israel 
Published: November 2003

ABSTRACT
During herpes simplex virus type 1 (HSV-1) latent infection in human peripheral sensory ganglia, the major viral gene transcribed is the latency-associated transcript (LAT) gene. In order to facilitate the study of this gene, we generated a transgenic mouse that contains the DNA fragment that transcribes the LAT RNAs (2.0 kb and its 1.5-kb spliced transcript) under control of the cytomegalovirus promoter. The tissue distribution of these transcripts and their effects upon HSV-1 replication, latency, and reactivation in the transgenic-mouse model were examined. Different steady-state amounts of both transcripts were found in various tissues. While the highest levels of the 2.0-kb RNA were detected in heart and skeletal muscle, the 1.5-kb transcript was found at elevated levels in the brain and at much higher levels in the trigeminal ganglia (TG). Replication of both the wild-type and a LAT-negative mutant virus was suppressed in primary embryonic fibroblasts obtained from LAT-expressing transgenic mice compared to that in cells obtained from normal mice. HSV-1 DNA amounts in latently infected TG of transgenic mice were similar to those in normal mice. Reactivation of latent HSV-1 LAT-negative mutants by explant cocultivation of TG from transgenic mice was more efficient than reactivation from normal-mouse TG. Considering our present and previous results, we propose that the significantly higher steady-state level of the 1.5-kb RNA in the TG may link this transcript to latency functions and that by inhibition of virus replication, the LAT gene may protect ganglion cells and thereby increase the probability of reactivation.
Methylation Patterns of Papillomavirus DNA, Its Influence on E2 Function, and Implications in Viral Infection
Authors: Kim Kitai , Garner-Hamrick Peggy A. , Fisher Chris , Lee Denis , Lambert Paul F. 
Published: November 2003

ABSTRACTThe biological activities of the papillomavirus E2 protein in transcription, replication, and maintenance of the papillomavirus genome rely on the E2 protein's ability to bind that genome specifically. The E2 binding sites (E2BSs), located within the long control region (LCR) of human papillomavirus (HPV) genomes, contain potential sites for 5′methylation at cytosine (CpG) residues. The E2 protein's capacity to bind E2BS in vitro is inhibited by methylation of these cytosines (59). Herein, we describe experiments to assess the influence of methylation on E2 function in cells. E2's ability to activate transcription was inhibited by the global methylation of CpG dinucleotides in E2-responsive transcriptional templates or when only the CpG dinucleotides within the E2BSs of a transcriptional template were methylated. Thus at least one biological activity of E2 that is dependent on its ability to bind DNA in a site-specific manner is influenced by the methylation status of its cognate binding site. The activity of DNA methylases is influenced by the differentiation status of mammalian cells. The life cycle of HPVs is tied to the differentiation of its host cells within stratified squamous epithelia. To investigate whether methylation of the papillomavirus genomes is influenced by the differentiation status of host epithelial cells, we analyzed HPV16 DNA harvested from a cervical epithelial cell line that was isolated from an HPV16-infected patient. We found, using bisulfite treatment to discriminate between methylated and unmethylated cytosines, that the HPV16 LCR was selectively hypomethylated in highly differentiated cell populations. In contrast, the HPV16 LCR from poorly differentiated, basal cell-like cells contained multiple methylated cytosines and were often methylated at E2BSs, particularly E2BS2. These experiments indicate that the methylation state of the viral genome, and particular that of E2BSs, may vary during the viral life cycle, providing a novel means for modulating E2 function. These studies also uncovered an extensive pattern of methylation at non-CpG dinucleotides indicative of de novo methylation. The potential implications of this de novo methylation pattern are discussed.
Retrospective Analysis of a Local Cessation of Vaccination against Poliomyelitis: a Possible Scenario for the Future
Authors: Korotkova Ekaterina A. , Park Renee , Cherkasova Elena A. , Lipskaya Galina Y. , Chumakov Konstantin M. , Feldman Esfir V. , Kew Olen M. , Agol Vadim I. 
Published: November 2003

ABSTRACT
The global eradication of poliomyelitis will require substantial changes in immunization practices. One of the proposed scenarios includes cessation of vaccination with live oral poliovirus vaccine (OPV) and the creation of an OPV stockpile for emergency response in case of the reintroduction of poliovirus into circulation. We describe here a retrospective analysis of the cessation of OPV usage in a region of the Byelorussian Republic of the former Soviet Union in 1963 to 1966. During this period, a widespread circulation and evolution of independent lineages of vaccine-derived polioviruses took place in the region. Some of these lineages appeared to originate from OPV given to 40 children in the community during this period of essentially no vaccinations. The data demonstrate very high risks associated with both the local cessation of OPV vaccination and the proposed use of OPV to control a possible reemergence of poliovirus in the postvaccination period. The high transmissibility of OPV-derived viruses in nonimmune population, documented here, and the known existence of long-term OPV excretors should be also considered in assessing risks of the synchronized global cessation of OPV usage.
Modulation of Minute Virus of Mice Cytotoxic Activities through Site-Directed Mutagenesis within the NS Coding Region
Authors: Daeffler Laurent , Hörlein Rita , Rommelaere Jean , Nüesch Jürg P. F. 
Published: November 2003

ABSTRACT
Late in infection, parvovirus minute virus of mice (MVMp) induces the lysis of mouse A9 fibroblasts. This effect depends on the large nonstructural phosphoprotein NS1, which plays in addition a major role in viral DNA replication and progeny particle production. Since the NS1 C-terminal region is subjected to late phosphorylation events and protein kinase C (PKC) family members regulate NS1 replicative activities, the present study was conducted to determine the impact of PKCs on NS1 cytotoxic functions. To this end, we performed site-directed mutagenesis, substituting alanine residues for two consensus PKC-phosphorylation sites located within the NS1 C-terminal region, T585 and S588. Although these substitutions had no detectable effect on virus multiplication in a single-round infection, the NS1-585A mutant virus was significantly less toxic to A9 cells than wild-type MVMp, whereas the NS1-588A mutant virus was endowed with a higher killing potential. These alterations correlated with specific changes in the late phosphorylation pattern of the mutant NS1 proteins compared to the wild-type polypeptide. Since the mutations introduced in this region of the viral genome also made changes in the minor nonstructural protein NS2, a contribution of this polypeptide to the above-mentioned phenotypes of mutant viruses cannot be excluded at present. However, the involvement of NS1 in these phenotypes was directly supported by the respective reduced and enhanced capacity of NS1-585A and NS1-588A recombinant proteins for inducing morphological alterations and cell detachment in transfected A9 cultures. Altogether, these data suggest that late-occurring phosphorylation of NS1 specifically regulates the cytotoxic functions of the viral product and that residues T585 and S588 contribute to this control in an antagonistic way.
Kinetics of Lymphocyte Proliferation during Primary Immune Response in Macaques Infected with Pathogenic Simian Immunodeficiency Virus SIVmac251: Preliminary Report of the Effect of Early Antiviral Therapy
Authors: Benlhassan-Chahour Kadija , Penit Claude , Dioszeghy Vincent , Vasseur Florence , Janvier Geneviève , Rivière Yves , Dereuddre-Bosquet Nathalie , Dormont Dominique , Le Grand Roger , Vaslin Bruno 
Published: November 2003

ABSTRACTThe aim of this study was to evaluate the kinetics of lymphocyte proliferation during primary infection of macaques with pathogenic simian immunodeficiency virus (SIV) and to study the impact of short-term postexposure highly active antiretroviral therapy (HAART) prophylaxis. Twelve macaques were infected by intravenous route with SIVmac251 and given treatment for 28 days starting 4 h postexposure. Group 1 received a placebo, and groups 2 and 3 received combinations of zidovudine (AZT), lamivudine (3TC), and indinavir. Macaques in group 2 received AZT (4.5 mg/kg of body weight), 3TC (2.5 mg/kg), and indinavir (20 mg/kg) twice per day by the oral route whereas macaques in group 3 were given AZT (4.5 mg/kg) and 3TC (2.5 mg/kg) subcutaneously twice per day, to improve the pharmacokinetic action of these drugs, and a higher dose of indinavir (60 mg/kg). The kinetics of lymphocyte proliferation were analyzed by monitoring 5-bromo-2′-deoxyuridine (BrdU) uptake ex vivo and by fluorescence-activated cell sorting analysis. HAART did not protect against SIV infection but did strongly impact on virus loads: viremia was delayed and lowered during antiviral therapy in group 2, with better control after treatment was stopped, and in group 3, viremia was maintained at lower levels during treatment, with virus even undetectable in the blood of some macaques, but there was no evidence of improved control of the virus after treatment. We provide direct evidence that dividing NK cells are detected earlier than dividing T cells in the blood (mostly in CD45RA−T cells), mirroring plasma viremia. Dividing CD8+T cells were detected earlier than dividing CD4+T cells, and the highest percentages of proliferating T cells coincided with the first evidence of partial control of peak viremia and with an increase in the percentage of circulating gamma interferon-positive CD8+T cells. The level of cell proliferation in the blood during SIV primary infection was clearly associated with viral replication levels because the inhibition of viral replication by postexposure HAART strongly reduced lymphocyte proliferation. The results and conclusions in this study are based on experiments in a small numbers of animals and are thus preliminary.
Bystander Killing during Avian Leukosis Virus Subgroup B Infection Requires TVB
S3
Signaling
Authors: Diaz-Griffero Felipe , Hoschander Steven A. , Brojatsch Jürgen 
Published: November 2003

ABSTRACT

Cell killing by avian leukosis virus subgroup B (ALV-B) in cultures has been extensively studied, but the molecular basis of this process has not been established. Here we show that superinfection, which has been linked to cell killing by ALV-B, plays no crucial role in cell death induction. Instead, we show that signaling by the ALV-B receptor, TVB
S3
, a member of the tumor necrosis factor receptor family, is essential for ALV-B-mediated cell death. TVB
S3
activated caspase-dependent apoptosis during ALV-B infection. Strikingly, apoptosis induction occurred predominantly in uninfected cells, while ALV-B-infected cells were protected against cell death. This bystander killing phenomenon was reproduced in a virus-free system by cocultivating ALV-B Env-expressing cells with TVB
S3
-expressing cells. Taken together, our results indicated that ALV-B-mediated apoptosis is triggered by ALV-B Env-TVB
S3
interactions.