bluuebunny/crossref_metadata_2025 huggingface dataset:
Association of Age at First Drink With Current Alcohol Drinking Variables in a National General Population Sample
Authors: York James L. , Welte John , Hirsch Judith , Hoffman Joseph H. , Barnes Grace
Published: September 2004

Background: Age at first drink has been found to be associated with alcohol problems in adulthood, but little is known regarding the relationship of age at first drink and current alcohol intake variables. This study was designed to determine the relationship of age at first drink to traditional drinking variables as well as novel current drinking variables assessed for the first time in a national general population sample.

Method: Data on age of first drink, pathological drinking (DSM‐IV alcohol abuse or dependence) and alcohol intake on typical drinking occasions were collected on a national general population sample of 2631 subjects by means of computerized telephone interviewing. Variables assessed for the first time in a national survey included the duration of the typical drinking episode and the predicted peak blood alcohol levels achieved during those episodes.

Results: Data from 2276 subjects who reported an age at first drink were used in this study. Men and lifetime pathological drinkers reported an earlier age at first drink than did, respectively, women or lifetime nonpathological drinkers. There were significant regression coefficients between age at first drink and several current drinking measures. The largest coefficients were usually found within younger age groups.

Conclusions: Age at first drink may be a useful predictive variable for some current drinking measures, including predicted peak blood alcohol levels as well as lifetime alcohol pathology. Further support was provided for the “convergence” hypothesis that the drinking habits of women have become more like those of men.
Multicenter Validation Study of the %CDT TIA Kit in Alcohol Abuse and Alcohol Dependence
Authors: Schwan Raymund , Loiseaux Marie‐Nadia , Schellenberg François , Albuisson Eliane , Favre Jean‐Dominique , Rigaud Alain , Llorca Pierre‐Michel , Gillet Claudine , Reynaud Michel
Published: September 2004

Background: Carbohydrate‐deficient transferrin (CDT) and γ‐glutamyl transferase (GGT) are used as biomarkers of alcohol misuse. The aim of this study was to evaluate, in terms of sensitivity and specificity, the performance of the new Bio‐Rad %CDT TIA kit and GGT assay for identifying alcohol abuse and alcohol dependence (according to the DSM‐IV criteria).

Methods: An open multicenter study (30 centers) over 3 months, including patient groups of “abusers,”“dependents,” and controls, was conducted in France.

Results: In alcohol abuse, the sensitivity of GGT was 0.56, and that of CDT was 0.80; in alcohol dependence, the sensitivity of GGT was 0.86, and that of CDT was 0.91. The specificity of GGT was 0.77, and that of CDT was 0.83. The association of GGT with CDT increased sensitivity for alcohol abuse to 0.90 and for alcohol dependence to 0.99, but it appreciably decreased specificity (0.63).

Conclusions: %CDT is the better screening marker for alcohol abuse and dependence, but GGT is still a useful marker for the detection of alcohol dependence. As an assay method, the second‐generation Bio‐Rad %CDT immunoassay can be recommended for routine CDT measurement.
Executive Functioning Early in Abstinence From Alcohol
Authors: Zinn Sandra , Stein Roy , Swartzwelder H Scott
Published: September 2004

Background:Executive dysfunction is among the cognitive impairments that may persist after abstinence in alcohol‐dependent persons. The type(s) and extent of executive dysfunction early in abstinence have not been well characterized, but they may have important implications for the evolution of behavioral treatment strategies.

Methods:To determine which aspects of executive functioning were impaired in early abstinence, we administered memory and executive function tests to veterans who successively presented for treatment at an outpatient substance abuse clinic. We then compared the neuropsychological performance of these recovering alcoholics (n= 27) with that of age‐matched primary care outpatients (n= 18). We also examined group differences in self‐evaluation of cognitive decline and evaluated associations between drinking history and cognitive impairment in the index group.

Results:We found that the normal and alcohol‐dependent groups differed on abstract reasoning, memory discrimination, and effectiveness on timed tasks. Patients in the alcohol‐dependent sample were also more likely to perceive themselves as cognitively impaired. It is interesting to note that the duration of alcohol use did not relate to neuropsychological test performance, but recent quantity consumed and days of sobriety were associated with nonverbal abstract reasoning ability.

Conclusions:Executive functions are impaired early in abstinence and should, therefore, be taken into account when early behavioral treatments are being developed.
A Review of Genetic, Biological, Pharmacological, and Clinical Factors That Affect Carbohydrate‐Deficient Transferrin Levels
Authors: Fleming Michael F. , Anton Raymond F. , Spies Claudia D.
Published: September 2004

Background: Carbohydrate‐deficient transferrin (CDT) is an alcohol biomarker recently approved by the U.S. Food and Drug Administration. This test is increasingly being used to detect and monitor alcohol use in a variety of health care, legal, and industrial settings. The goal of this study is to review the genetic, biological, pharmacological, and clinical factors that may affect CDT levels.

Methods: A review of the literature identified 95 research articles that met the authors’ criteria and reported potential interactions of a variety of factors on percent and total CDT levels. The review established 12 categories of variables that may affect CDT levels. These categories include (1) alcohol use, (2) genetic factors, (3) race, (4) gender, (5) age, (6) liver disease, (7) iron levels, (8) tobacco use, (9) medication such as estrogen and anticonvulsants, (10) metabolic factors such as body mass index and total body water, (11) chronic medical conditions such as rheumatoid arthritis, and (12) surgical patients.

Results: There is evidence that %CDT levels are affected by alcohol use, end‐stage liver disease, and genetic variants. In addition to these three factors, total CDT levels (CDTect) are also affected by factors that raise transferrin levels such as iron deficiency, chronic illnesses, and menopausal status. Other potential factors such as tobacco and age appear to be confounded by alcohol use. The roles of female gender, low body mass index, chronic inflammatory diseases, and medication on CDT levels require further study. False negatives are associated with female gender, episodic lower level alcohol use, and acute trauma with blood loss.

Conclusions: This review suggests that a number of factors are associated with false‐positive CDTect and %CDT levels. CDT offers great promise to assist physicians in the care of patients to detect and monitor heavy alcohol use.
Differential Effects of Ethanol on γ‐Aminobutyric Acid‐A Receptor‐Mediated Synaptic Currents in Congenic Strains of Inbred Long and Short‐Sleep Mice
Authors: Proctor William R. , Wu Peter H. , Bennett Beth , Johnson Thomas E.
Published: September 2004

Background: Ethanol enhances γ‐aminobutyric acid (GABA)A receptor‐mediated responses in the brain, and this enhancement is greater in a mouse line behaviorally more sensitive to ethanol (long sleep) than in a line (short sleep) behaviorally less ethanol sensitive (assayed by loss of righting; sleep time). Quantitative trait locus (QTL) analysis of inbred long sleep (ILS) and inbred short sleep (ISS) phenotypes revealed four chromosomal regions (Lore1, Lore2, Lore4, and Lore5) that together account for approximately 50% of ethanol‐induced sleep‐time variance. Congenic strains were generated, each of which is homozygous for one of four ISS Lore QTLs on the ILS background. These congenic mouse strains are ideally suited for asking which QTL regions might correlate with other phenotypes that differ between ILS and ISS mice. Here we used the congenics to investigate altered GABAA responses to ethanol.

Methods: Evoked GABAA receptor‐mediated inhibitory postsynaptic currents (IPSCs) were measured by whole‐cell voltage‐clamp recording procedures in CA1 pyramidal neurons in hippocampal brain slices.

Results: GABAA IPSC responses in hippocampal brain slices from ILS mice were significantly enhanced by 80 mM ethanol, whereas those from ISS mice were not affected. ILS.Lore2S and ILS.Lore5S congenic strains were significantly enhanced by 80 mM ethanol, similar to the background (control) ILS mice. However, ethanol had no significant effect on GABAA responses in ILS.Lore1S and ILS.Lore4S congenic mice, similar to the ISS mice, thus reflecting the influence of ISS alleles on the ILS phenotype.

Conclusions: Our results suggest that alleles located in the Lore1 and Lore4 QTL regions confer ethanol sensitivity of GABAA receptor‐mediated IPSCs. Thus, for these QTLs, GABAA IPSCs may represent an endophenotype of sedative/hypnotic sensitivity to ethanol. Although the Lore2 and Lore5 QTL regions have a significant effect on sleep time, they do not play a significant role in the differential ethanol enhancement of GABAA IPSCs between ILS and ISS mice.
Acute Ethanol‐Induced Adenosine Diphosphate Ribosylation Regulates the Functional Activity of Rat Striatal Pertussis Toxin–Sensitive G Proteins
Authors: Dar M Saeed , Meng Z ‐H.
Published: September 2004

Background: We demonstrated previously that striatal adenosine modulates ethanol‐induced motor incoordination (EIMI) via adenosine A1 receptors coupled to pertussis toxin (PT)‐sensitive G protein and adenylyl cyclase‐cyclic adenosine monophosphate (cAMP). Additionally, intrastriatal (IST) PT antagonizes EIMI and its potentiation by the adenosine A1 agonist N6‐cyclohexyladenosine; it also inhibits cAMP concentration.

Methods: Guide cannulas were stereotaxically implanted for IST pretreatment with PT followed 5 days later by IST of N6‐cyclohexyladenosine and intraperitoneal ethanol. The adenosine diphosphate (ADP) ribosylation reaction involved PT‐catalyzed [32P]nicotinamide adenine dinucleotide (NAD) labeling of rat striatal membranes. Antagonism of EIMI (Rotorod method) after IST microinfusion of PT was investigated to determine whether it was due to a decrease in the functional activity of G proteins due to ADP ribosylation of the Giα subunit caused it.

Results: Striatal membranes from IST PT (0.5 μg)–treated animals exhibited significantly attenuated (up to 90%) in vitro ADP ribosylation with [32P]NAD. Striatal membranes from animals injected with ethanol (1.5 g/kg intraperitoneally) exhibited statistically significant increase (11%) in in vitro ADP ribosylation. Similarly, ethanol (50 mM) added to striatal membranes from untreated animals produced significant stimulation of in vitro ADP ribosylation. The decrease in the functional activity of G proteins due to ADP ribosylation of the Giα subunit after IST PT was functionally correlated with marked attenuation in EIMI, as observed previously. This finding suggests a blockade of functional activity of PT‐sensitive striatal Gi/Go proteins (i.e., fewer available sites for labeled NAD incorporation). The in vivo ethanol results indicate that it must have caused an increase in the ribosylation capacity of Giα in vivo (i.e., increased Gi activity). Increased ADP ribosylation by in vitro ethanol increases Gi/Go activity, consistent with EIMI, as previously reported.

Conclusions: The results provide biochemical evidence of an ethanol‐induced increase in ADP ribosylation of Giα causing a decrease in the functional activity of G proteins coupled via Gi/Go to adenylyl cyclase‐cAMP. These results confirm the previously observed antagonism of EIMI by PT (IST).
CDT Values Are Not Influenced by Epithelial Cell Apoptosis in Chronic Alcoholic Patients—Preliminary Results
Authors: Ramskogler Katrin , Brunner Markus , Hertling Ines , Dvorak Alexander , Kapusta Nestor , Krenn Claus , Moser Bernhard , Roth Georg , Lesch Otto Michael , Ankersmit Hendrik Jan , Walter Henriette
Published: September 2004

Carbohydrate‐deficient transferrin (CDT) has been well established as a marker for high alcohol consumption. As studies concerning the specificity of CDT in patients with liver disease have shown controversial outcomes, efforts to illuminate mechanisms leading to impaired CDT specificity in this patient group cannot yet be considered successful. Evidence of apoptosis as examined in 72 alcohol‐dependent patients using serum contents of caspase‐related M30 monoclonal antibody significantly correlated with aspartate aminotransferase, alanine aminotransferase, and γ‐glutamyl transpeptidase but did not influence CDT levels. These results suggest that impairment of CDT specificity is brought forth by derangement of hepatic metabolism rather than by acute hepatocellular damage.
Trends in Drinking Among Americans Age 18 and Younger: 1975–2002
Authors: Faden Vivian B. , Fay Michael P.
Published: September 2004

Background: Although changes over time in the prevalence of drinking by youth under 18 have been previously reported, we present results based on data from multiple surveys, using recently developed software for trend analyses. In this study, we applied joinpoint statistical methodology to three national data sets to analyze trends in drinking by youth, age 18 and under, for the period 1975 to 2002.

Methods: Information was obtained from three national data sets, Monitoring the Future for the years 1975 to 2002, the Youth Risk Behavior Survey for the years 1991 to 2001, and the National Household Survey on Drug Abuse for 1979, 1985, and 1991 to 2001.

Approximately 80,000 persons between 12 and 18 were included in the most recent survey years. The alcohol consumption measures examined over time were any use of alcohol, consumption of five or more drinks on one occasion, and daily consumption.

Results: Alcohol consumption by 8th, 10th and 12th graders decreased substantially since the 1970s according to joinpoint trend analyses. It remains disturbingly high, however, according to data from three national surveys (e.g., 12.4% of 8th and 28.6% of 12th graders drinking five or more drinks in a row in the past 2 weeks), although prevalence rates have been relatively stable for the last 5 to 10 years.

Conclusions: Since the early 1990s, rates of drinking by youth under 18 remained relatively stable according to the Youth Risk Behavior Survey and National Household Survey on Drug Abuse and moved up and then down according to Monitoring the Future, underscoring the need for continued surveillance and enhanced understanding of this long‐standing problem.
Ethanol Operant Self‐Administration in Rats Is Regulated by Adenosine A2 Receptors
Authors: Arolfo Maria Pia , Yao Lina , Gordon Adrienne S. , Diamond Ivan , Janak Patricia H.
Published: September 2004

Background: Recent findings suggest that adenosine is involved in the neural and behavioral effects of ethanol (EtOH). Studies in neural cell culture show that EtOH, via activation of adenosine A2 receptors, triggers cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signaling and CRE (cAMP regulatory element)‐mediated gene expression and that this effect is blocked by inhibiting G‐protein βγ subunits. Recently, we reported that expression of a βγ inhibitor in the nucleus accumbens (NAc) reduces EtOH drinking in rats. The NAc expresses high levels of the adenosine A2A receptor in GABAergic medium spiny neurons. If the reinforcing effects of EtOH are mediated through an A2 activation of cAMP/PKA signaling via βγ, then A2 receptor blockade should attenuate EtOH consumption. Here we tested this hypothesis. Because adenosine A2 and dopamine D2 receptors are coexpressed in neurons of the NAc, we compared the effects of A2 blockade with those of D2 receptor blockade.

Methods: Male Long‐Evans rats were trained to self‐administer 10% EtOH in daily 30‐min sessions with an active and an inactive lever. Separate groups of rats were given the D2 antagonist eticlopride (0.005, 0.007, and 0.01 mg/kg), the A2 antagonist 3,7‐dimethyl‐1‐propargylxanthine (DMPX; 1, 3, 5, 7, 10, and 20 mg/kg), and the A1 antagonist 8‐cyclopentyl‐1,3‐dipropylxanthine (DPCPX; 0.125, 0.25, and 0.5 mg/kg) by systemic injection.

Results: Eticlopride dose‐dependently reduced EtOH drinking. DMPX showed a bimodal effect: 10 and 20 mg/kg decreased, but 1 mg/kg increased, EtOH consumption. DPCPX was without effect.

Conclusions: In support of our hypothesis, the A2 antagonist DMPX attenuated EtOH self‐administration. Low doses of the A2 antagonist enhanced EtOH drinking, consistent with the possibility that rats increase EtOH self‐administration to overcome partial A2 blockade. The D2 antagonist eticlopride also decreased EtOH self‐administration. These data provide the first evidence that pharmacological modulation of adenosine A2 receptors can regulate EtOH consumption in rats.
Does an Energy Drink Modify the Effects of Alcohol in a Maximal Effort Test?
Authors: Ferreira Sionaldo Eduardo , de Mello Marco Túlio , Rossi Marcio Vinicius , Souza‐Formigoni Maria Lucia O.
Published: September 2004

Background: There are popular reports on the combined use of alcohol and energy drinks (such as Red Bull® and similar beverages, which contain caffeine, taurine, carbohydrates, etc.) to reduce the depressant effects of alcohol on central nervous system, but no controlled studies have been performed. The main purpose of this study was to verify the effects of alcohol, and alcohol combined with energy drink, on the performance of volunteers in a maximal effort test (cycle ergometer) and also on physiological indicators (oxygen uptake, ventilatory threshold, respiratory exchange rate, heart rate, and blood pressure), biochemical variables (glucose, lactate, insulin, cortisol, ACTH, dopamine, noradrenaline, and adrenaline), and blood alcohol levels.

Methods: Fourteen healthy subjects completed a double‐blind protocol made up of four sessions: control (water), alcohol (1.0 g/kg), energy drink (3.57 ml/kg Red Bull®), and alcohol + energy drink, each 1 week apart. The effort test began 60 min after drug or control ingestion, and the dependent variables were measured until 60 min after the test.

Results: Heart rate at the ventilatory threshold was higher in the alcohol and alcohol + energy drink sessions in comparison with control and energy drink sessions. Although in comparison to the control session, the peak oxygen uptake was 5.0% smaller after alcohol ingestion, 1.4% smaller after energy drink, and 2.7% smaller after the combined ingestion, no significant differences were detected. Lactate levels (30 min after drug ingestion, 30 and 60 min after the effort test) and noradrenaline levels (30 min after the effort test) were higher in the alcohol and alcohol + energy drink sessions compared with the control session.

Conclusions: The performance in the maximal effort test observed after alcohol + energy drink ingestion was similar to that observed after alcohol only. No significant differences between alcohol and alcohol + energy drink were detected in the physiological and biochemical parameters analyzed. Our findings suggest that energy drinks, at least in the tested doses, did not improve performance or reduce alterations induced by acute alcohol ingestion.
Serum Levels of Tissue Polypeptide Specific Antigen Are Correlated With Hepatocyte Cytokeratin Expression in Alcoholic Liver Disease
Authors: Gonzalez‐Quintela A , Mella C , Abdulkader I , Perez L F. , Campos J , Otero E , Forteza J
Published: September 2004

Background: Serum levels of the tumor marker tissue polypeptide specific antigen (TPS, cytokeratin 18 fragments) are increased in patients with alcoholic liver disease, particularly in cases of alcoholic hepatitis. Mallory bodies, characteristic of alcoholic hepatitis, are cytokeratin 8 and 18 aggregates. The study was aimed at investigating the possible relationship of serum TPS levels with hepatocyte cytokeratin expression in patients with alcoholic liver disease.

Methods: Twenty‐four patients with alcoholic liver disease were studied. Immunohistochemical staining for cytokeratins 8 and 18 was performed in liver specimens by means of CAM 5.2 monoclonal antibody. The number of hepatocytes containing CAM 5.2‐reactive cytokeratin inclusions was compared with serum TPS levels.

Main Results and Conclusions: The vast majority of alcoholics (95%) showed increased (>100 units/liter) serum TPS levels. Serum TPS levels were significantly correlated with the number of hepatocyte cytokeratin inclusions. Serum TPS levels can predict hepatocyte cytokeratin expression in patients with alcoholic liver disease.
Chronic Ethanol‐Induced Subtype‐ and Subregion‐Specific Decrease in the mRNA Expression of Metabotropic Glutamate Receptors in Rat Hippocampus
Authors: Simonyi Agnes , Christian Michael R. , Sun Albert Y. , Sun Grace Y.
Published: September 2004

Background: Chronic ethanol consumption is known to induce adaptive changes in the hippocampal glutamatergic transmission and alter NMDA receptor binding and subunit expression. Metabotropic glutamate (mGlu) receptors have been shown to function as modulators of neuronal excitability and can fine tune glutamatergic transmission. This study was aimed to determine whether chronic ethanol treatment could change the messenger RNA (mRNA) expression of mGlu receptors in the hippocampus.

Methods: Male Sprague Dawley® rats were fed a Lieber‐DeCarli liquid diet with 5% (w/v) ethanol or isocaloric amount of maltose for 2 months. Quantitative in situ hybridization was carried out using coronal brain sections through the hippocampus.

Results: The results revealed decreases in mRNA expression of several mGlu receptors in different subregions of the hippocampus. In the dentate gyrus, mGlu3 and mGlu5 receptor mRNA levels were significantly lower in the ethanol‐treated rats than in the control rats. In the CA3 region, the mRNA expression of mGlu1, mGlu5, and mGlu7 receptors showed substantial decreases after ethanol exposure. The mGlu7 receptor mRNA levels were also declined in the CA1 region and the polymorph layer of the dentate gyrus. No changes were found in mRNA expression of mGlu2, mGlu4, and mGlu8 receptors.

Conclusions: Considering the involvement of hippocampal mGlu receptors in learning and memory processes as well as in neurotoxicity and seizure production, the reduced expression of these receptors might contribute to ethanol withdrawal‐induced seizures and also may play a role in cognitive deficits and brain damage caused by long‐term ethanol consumption.
Implicit Strategy Affects Learning in Children With Heavy Prenatal Alcohol Exposure
Authors: Roebuck‐Spencer Tresa M. , Mattson Sarah N.
Published: September 2004

Background: Learning and memory deficits are commonly reported in children with heavy prenatal alcohol exposure. Our recent work suggested that children with heavy prenatal alcohol exposure retained information as well as controls on a verbal learning test but not on a test of nonverbal learning and memory. To better understand the cause of this differential pattern of performance, the current study re‐analyzed data from our previous study to determine if the presence of an implicit learning strategy may account, at least in part, for the finding of spared retention.

Methods: The current study examined verbal learning and memory abilities in 35 children with Fetal Alcohol Spectrum Disorders (FASD) and 34 nonexposed controls (CON) matched for age (9–16 years), sex, ethnicity, handedness, and socioeconomic status. Groups were compared on two measures of verbal learning, one with an implicit strategy (California Verbal Learning Test–Children's Version; CVLT‐C) and one without (Verbal Learning subtest of the Wide Range Assessment of Memory and Learning; VL‐WRAML).

Results: Children with FASD learned less information overall than children in the CON group. Both groups learned a greater percentage of information and reached a learning plateau earlier on the CVLT‐C compared with the VL‐WRAML. Groups also showed comparable rates of retention after a delay on the CVLT‐C. In contrast, on the VL‐WRAML, children with FASD showed poorer retention rates than children in the CON group. Interestingly, children with FASD did not differ from children in the CON group on CVLT‐C semantic clustering scores for learning trials 1 through 3, and greater utilization of semantic clustering was correlated with better learning and memory performance in both groups. This overall pattern of results was not related to overall intellectual level.

Conclusions: The finding of spared retention of verbal information on the CVLT‐C in our earlier studies may be related to test characteristics of the CVLT‐C rather than a finding of spared verbal retention per se, given that spared retention was not found on a separate test of verbal learning and memory without an implicit learning strategy. These results suggest that the use of an implicit strategy positively affected the ability of alcohol‐exposed children to learn and retain new verbal information.
Increased P3 Amplitudes Induced by Alcohol‐Related Pictures in Patients With Alcohol Dependence
Authors: Namkoong Kee , Lee Eun , Lee Choong Heon , Lee Byung Ook , An Suk Kyoon
Published: September 2004

Background:Alcohol craving, a key element in alcohol dependence, is recognized as being a kind of motivational or emotional state. It is meaningful in research and clinical practice involving alcohol dependence to explore ways of measuring alcohol craving. The aim of this study was to measure the P3 event‐related potentials induced by alcohol‐related pictures in patients with alcohol dependence; these potentials are considered to constitute a neuronal correlate of alcohol craving.

Methods:On the basis of our previous study, six alcohol‐related pictures and six neutral pictures were chosen as the visual stimuli. Each set of stimuli consisted of alcohol‐related or neutral pictures as the target stimuli and same‐sized checkerboards as the nontarget stimuli. The stimuli were presented by using the oddball paradigm for 300 msec, with an interstimulus interval of 1000 msec, in 12 controls and 16 abstinent patients with alcohol dependence. Each electroencephalography session consisted of three blocks: a practice block, a neutral block, and an alcohol‐craving block.

Results:The amplitudes of P3 elicited by the alcohol‐related pictures were significantly larger than those elicited by the neutral pictures in the patients with alcohol dependence, whereas there was no significant difference according to the stimuli in the P3 amplitudes of controls. Repeated‐measures ANOVA on the amplitudes of P3 revealed that there was a significant interaction effect of block by subject group.

Conclusions:These results suggest that event‐related potentials can be used as a neuronal correlate of alcohol craving in alcohol‐dependent patients. Future investigations will be needed to assess the frequency of relapse in the patients included in this study, to elucidate the meaning of the observed results with regard to the therapeutic outcomes.
Peripheral and Central Administration of a Selective Neuropeptide Y Y1 Receptor Antagonist Suppresses Ethanol Intake by C57BL/6J Mice
Authors: Sparta Dennis R. , Fee Jon R. , Hayes Dayna M. , Knapp Darin J. , MacNeil Douglas J. , Thiele Todd E.
Published: September 2004

Background: Neuropeptide Y (NPY) is a 36–amino acid neuromodulator that is expressed throughout the central nervous system. Recent genetic and pharmacological evidence suggests that the NPY Y1 receptor modulates ethanol intake. To further characterize the role of the Y1 receptor, we examined voluntary ethanol consumption by mice after administration of [(−)‐2‐[1‐(3‐chloro‐5‐isopropyloxycarbonylaminophenyl)ethylamino]‐6‐[2‐(5‐ethyl‐4‐methyl‐1,3‐tiazol‐2‐yl)ethyl]‐4‐morpholinopyridine] (compound A), a novel and selective Y1 receptor antagonist (Y1RA) that acts centrally on brain receptors when administered peripherally.

Methods: C57BL/6J mice were habituated to drinking a 10% (v/v) ethanol solution by using a two‐bottle‐choice procedure and were then given an intraperitoneal (ip) injection (5 ml/kg) of the Y1RA (0, 25, 50, or 75 mg/kg). In a second study, mice were given intracerebroventricular infusion of the Y1RA (0, 30, or 100 μg). Finally, we determined whether the Y1RA alters open‐field locomotor activity, ethanol‐induced sedation (3.8 g/kg, ip), or blood ethanol levels.

Results: Relative to control treatment, ip injection (50 and 75 mg/kg) and intracerebroventricular infusion (100 μg) of the Y1RA significantly reduced ethanol consumption and food intake without altering water drinking. However, the Y1RA did not alter open‐field locomotor activity, ethanol‐induced sedation, or blood ethanol levels.

Conclusions: These data indicate that acute blockade of the NPY Y1 receptor with a systemically bioavailable NPY Y1RA reduces voluntary ethanol consumption by C57BL/6J mice. These results are consistent with observations that hypothalamic infusion of NPY increases ethanol drinking by rats.
Wnt/β-catenin signaling is sufficient and necessary for synovial joint formation
Authors: Guo Xizhi , Day Timothy F. , Jiang Xueyuan , Garrett-Beal Lisa , Topol Lilia , Yang Yingzi
Published: September 2004

A critical step in skeletal morphogenesis is the formation of synovial joints, which define the relative size of discrete skeletal elements and are required for the mobility of vertebrates. We have found that several Wnt genes, including Wnt4, Wnt14, and Wnt16, were expressed in overlapping and complementary patterns in the developing synovial joints, where β-catenin protein levels and transcription activity were up-regulated. Removal of β-catenin early in mesenchymal progenitor cells promoted chondrocyte differentiation and blocked the activity of Wnt14 in joint formation. Ectopic expression of an activated form of β-catenin or Wnt14 in early differentiating chondrocytes induced ectopic joint formation both morphologically and molecularly. In contrast, genetic removal of β-catenin in chondrocytes led to joint fusion. These results demonstrate that the Wnt/β-catenin signaling pathway is necessary and sufficient to induce early steps of synovial joint formation. Wnt4, Wnt14, and Wnt16 may play redundant roles in synovial joint induction by signaling through the β-catenin-mediated canonical Wnt pathway.
Two Transcription Factors Are Negative Regulators of Gibberellin Response in the HvSPY-Signaling Pathway in Barley Aleurone
Authors: Robertson Masumi
Published: September 2004

SPINDLY (SPY) protein from barley (Hordeum vulgare L. cv Himalaya; HvSPY) negatively regulated GA responses in aleurone, and genetic analyses of Arabidopsis thaliana predict that SPY functions in a derepressible GA-signaling pathway. Many, if not all, GA-dependent responses require SPY protein, and to improve our understanding of how the SPY signaling pathway operates, a yeast two-hybrid screen was used to identify both upstream and downstream components that might regulate the activity of the HvSPY protein. A number of proteins from diverse classes were identified using HvSPY as bait and barley cDNA libraries as prey. Two of the HvSPY-interacting (HSI) proteins were transcription factors belonging to the myb and NAC gene families, HSImyb and HSINAC. Interaction occurred via the tetratricopeptide repeat domain of HvSPY and specificity was shown both in vivo and in vitro. Messenger RNAs for these proteins were expressed differentially in many parts of the barley plant but at very low levels. Both HSImyb and HSINAC inhibited the GA3 up-regulation of α-amylase expression in aleurone, both were activators of transcription in yeast, and the green fluorescent protein-HSI fusion proteins were localized in the nucleus. These results are consistent with the model that HSI transcription factors act downstream of HvSPY as negative regulators and that they in turn could activate other negative regulators, forming the HvSPY negative regulator-signaling pathway for GA response.
LESION SIMULATING DISEASE 1 Is Required for Acclimation to Conditions That Promote Excess Excitation Energy
Authors: Mateo Alfonso , Mühlenbock Per , Rustérucci Christine , Chang Christine Chi-Chen , Miszalski Zbigniew , Karpinska Barbara , Parker Jane E. , Mullineaux Philip M. , Karpinski Stanislaw
Published: September 2004

The lsd1 mutant of Arabidopsis fails to limit the boundaries of hypersensitive cell death response during avirulent pathogen infection and initiates unchecked lesions in long day photoperiod giving rise to the runaway cell death (rcd) phenotype. We link here the initiation and propagation of rcd to the activity of photosystem II, stomatal conductance and ultimately to photorespiratory H2O2. A cross of lsd1 with the chlorophyll a/b binding harvesting-organelle specific (designated cao) mutant, which has a reduced photosystem II antenna, led to reduced lesion formation in the lsd1/cao double mutant. This lsd1 mutant also had reduced stomatal conductance and catalase activity in short-day permissive conditions and induced H2O2 accumulation followed by rcd when stomatal gas exchange was further impeded. All of these traits depended on the defense regulators EDS1 and PAD4. Furthermore, nonphotorespiratory conditions retarded propagation of lesions in lsd1. These data suggest that lsd1 failed to acclimate to light conditions that promote excess excitation energy (EEE) and that LSD1 function was required for optimal catalase activity. Through this regulation LSD1 can influence the effectiveness of photorespiration in dissipating EEE and consequently may be a key determinant of acclimatory processes. Salicylic acid, which induces stomatal closure, inhibits catalase activity and triggers the rcd phenotype in lsd1, also impaired acclimation of wild-type plants to conditions that promote EEE. We propose that the roles of LSD1 in light acclimation and in restricting pathogen-induced cell death are functionally linked.
FRD3 Controls Iron Localization in Arabidopsis
Authors: Green Laura S. , Rogers Elizabeth E.
Published: September 2004

The frd3 mutant of Arabidopsis exhibits constitutive expression of its iron uptake responses and is chlorotic. These phenotypes are consistent with defects either in iron deficiency signaling or in iron translocation and localization. Here we present several experiments demonstrating that a functional FRD3 gene is necessary for correct iron localization in both the root and shoot of Arabidopsis plants. Reciprocal grafting experiments with frd3 and wild-type Arabidopsis plants reveal that the phenotype of a grafted plant is determined by the genotype of the root, not by the genotype of the shoot. This indicates that FRD3 function is root-specific and points to a role for FRD3 in delivering iron to the shoot in a usable form. When grown under certain conditions, frd3 mutant plants overaccumulate iron in their shoot tissues. However, we demonstrate by direct measurement of iron levels in shoot protoplasts that intracellular iron levels in frd3 are only about one-half the levels in wild type. Histochemical staining for iron reveals that frd3 mutants accumulate high levels of ferric iron in their root vascular cylinder, the same tissues in which the FRD3 gene is expressed. Taken together, these results clearly indicate a role for FRD3 in iron localization in Arabidopsis. Specifically, FRD3 is likely to function in root xylem loading of an iron chelator or other factor necessary for efficient iron uptake out of the xylem or apoplastic space and into leaf cells.
LWR1andLWR2Are Required for Osmoregulation and Osmotic Adjustment in Arabidopsis
Authors: Verslues Paul E. , Bray Elizabeth A.
Published: September 2004

With the goal of identifying molecular components of the low-water-potential response, we have carried out a two-part selection and screening strategy to identify new Arabidopsis mutants. Using a system of polyethylene glycol-infused agar plates to impose a constant low-water-potential stress, putative mutants impaired in low-water-potential induction of the tomato (Lycopersicon esculentum) le25 promoter were selected. These lines were then screened for altered accumulation of free Pro. The seedlings of 22 mutant lines had either higher or lower Pro content than wild type when exposed to low water potential. Two mutants, designated low-water-potential response1 (lwr1) and lwr2, were characterized in detail. In addition to higher Pro accumulation, lwr1 seedlings had higher total solute content, greater osmotic adjustment at low water potential, altered abscisic acid content, and increased sensitivity to applied abscisic acid with respect to Pro content. lwr1 also had altered growth and morphology. lwr2, in contrast, had lower Pro content and less osmotic adjustment leading to greater water loss at low water potential. Both lwr1 and lwr2 also had altered leaf solute content and water relations in unstressed soil-grown plants. In both mutants, the effects on solute content were too large to be explained by the changes in Pro content alone, indicating that LWR1 and LWR2 affect multiple aspects of cellular osmoregulation.
Expression Patterns of a Novel AtCHX Gene Family Highlight Potential Roles in Osmotic Adjustment and K+ Homeostasis in Pollen Development
Authors: Sze Heven , Padmanaban Senthilkumar , Cellier Françoise , Honys David , Cheng Ning-Hui , Bock Kevin W. , Conéjéro Genevieve , Li Xiyan , Twell David , Ward John M. , Hirschi Kendal D.
Published: September 2004

A combined bioinformatic and experimental approach is being used to uncover the functions of a novel family of cation/H+ exchanger (CHX) genes in plants using Arabidopsis as a model. The predicted protein (85–95 kD) of 28 AtCHX genes after revision consists of an amino-terminal domain with 10 to 12 transmembrane spans (approximately 440 residues) and a hydrophilic domain of approximately 360 residues at the carboxyl end, which is proposed to have regulatory roles. The hydrophobic, but not the hydrophilic, domain of plant CHX is remarkably similar to monovalent cation/proton antiporter-2 (CPA2) proteins, especially yeast (Saccharomyces cerevisiae) KHA1 and Synechocystis NhaS4. Reports of characterized fungal and prokaryotic CPA2 indicate that they have various transport modes, including K+/H+ (KHA1), Na+/H+-K+ (GerN) antiport, and ligand-gated ion channel (KefC). The expression pattern of AtCHX genes was determined by reverse transcription PCR, promoter-driven β-glucuronidase expression in transgenic plants, and Affymetrix ATH1 genome arrays. Results show that 18 genes are specifically or preferentially expressed in the male gametophyte, and six genes are highly expressed in sporophytic tissues. Microarray data revealed that several AtCHX genes were developmentally regulated during microgametogenesis. An exciting idea is that CHX proteins allow osmotic adjustment and K+ homeostasis as mature pollen desiccates and then rehydrates at germination. The multiplicity of CHX-like genes is conserved in higher plants but is not found in animals. Only 17 genes, OsCHX01 to OsCHX17, were identified in rice (Oryza sativa) subsp. japonica, suggesting diversification of CHX in Arabidopsis. These results reveal a novel CHX gene family in flowering plants with potential functions in pollen development, germination, and tube growth.
A Second Protein l-Isoaspartyl Methyltransferase Gene in Arabidopsis Produces Two Transcripts Whose Products Are Sequestered in the Nucleus
Authors: Xu Qilong , Belcastro Marisa P. , Villa Sarah T. , Dinkins Randy D. , Clarke Steven G. , Downie A. Bruce
Published: September 2004

The spontaneous and deleterious conversion of l-asparaginyl and l-aspartyl protein residues to l-iso-Asp or d-Asp occurs as proteins age and is accelerated under stressful conditions. Arabidopsis (Arabidopsis L. Heynh.) contains two genes (At3g48330 and At5g50240) encoding protein-l-isoaspartate methyltransferase (EC 2.1.1.77; PIMT), an enzyme capable of correcting this damage. The gene located on chromosome 5 (PIMT2) produces two proteins differing by three amino acids through alternative 3′ splice site selection in the first intron. Recombinant protein from both splicing variants has PIMT activity. Subcellular localization using cell fractionation followed by immunoblot detection, as well as confocal visualization of PIMT:GFP fusions, demonstrated that PIMT1 is cytosolic while a canonical nuclear localization signal, present in PIMT2ψ and the shorter PIMT2ω, is functional. Multiplex reverse transcription-PCR was used to establish PIMT1 and PIMT2 transcript presence and abundance, relative to β-TUBULIN, in various tissues and under a variety of stresses imposed on seeds and seedlings. PIMT1 transcript is constitutively present but can increase, along with PIMT2, in developing seeds presumably in response to increasing endogenous abscisic acid (ABA). Transcript from PIMT2 also increases in establishing seedlings due to exogenous ABA and applied stress presumably through an ABA-dependent pathway. Furthermore, cleaved amplified polymorphic sequences from PIMT2 amplicons determined that ABA preferentially enhances the production of PIMT2ω transcript in leaves and possibly in tissues other than germinating seeds.
The Potassium-Dependent Transcriptome of Arabidopsis Reveals a Prominent Role of Jasmonic Acid in Nutrient Signaling
Authors: Armengaud Patrick , Breitling Rainer , Amtmann Anna
Published: September 2004

Full genome microarrays were used to assess transcriptional responses of Arabidopsis seedlings to changing external supply of the essential macronutrient potassium (K+). Rank product statistics and iterative group analysis were employed to identify differentially regulated genes and statistically significant coregulated sets of functionally related genes. The most prominent response was found for genes linked to the phytohormone jasmonic acid (JA). Transcript levels for the JA biosynthetic enzymes lipoxygenase, allene oxide synthase, and allene oxide cyclase were strongly increased during K+ starvation and quickly decreased after K+ resupply. A large number of well-known JA responsive genes showed the same expression profile, including genes involved in storage of amino acids (VSP), glucosinolate production (CYP79), polyamine biosynthesis (ADC2), and defense (PDF1.2). Our findings highlight a novel role of JA in nutrient signaling and stress management through a variety of physiological processes such as nutrient storage, recycling, and reallocation. Other highly significant K+-responsive genes discovered in our study encoded cell wall proteins (e.g. extensins and arabinogalactans) and ion transporters (e.g. the high-affinity K+ transporter HAK5 and the nitrate transporter NRT2.1) as well as proteins with a putative role in Ca2+ signaling (e.g. calmodulins). On the basis of our results, we propose candidate genes involved in K+ perception and signaling as well as a network of molecular processes underlying plant adaptation to K+ deficiency.
Arabidopsis Cys2/His2-Type Zinc-Finger Proteins Function as Transcription Repressors under Drought, Cold, and High-Salinity Stress Conditions
Authors: Sakamoto Hideki , Maruyama Kyonoshin , Sakuma Yoh , Meshi Tetsuo , Iwabuchi Masaki , Shinozaki Kazuo , Yamaguchi-Shinozaki Kazuko
Published: September 2004

ZPT2-related proteins that have two canonical Cys-2/His-2-type zinc-finger motifs in their molecules are members of a family of plant transcription factors. To characterize the role of this type of protein, we analyzed the function of Arabidopsis L. Heynh. genes encoding four different ZPT2-related proteins (AZF1, AZF2, AZF3, and STZ). Gel-shift analysis showed that the AZFs and STZ bind to A(G/C)T repeats within an EP2 sequence, known as a target sequence of some petunia (Petunia hybrida) ZPT2 proteins. Transient expression analysis using synthetic green fluorescent protein fusion genes indicated that the AZFs and STZ are preferentially localized to the nucleus. These four ZPT2-related proteins were shown to act as transcriptional repressors that down-regulate the transactivation activity of other transcription factors. RNA gel-blot analysis showed that expression of AZF2 and STZ was strongly induced by dehydration, high-salt and cold stresses, and abscisic acid treatment. Histochemical analysis of β-glucuronidase activities driven by the AZF2 or STZ promoters revealed that both genes are induced in leaves rather than roots of rosette plants by the stresses. Transgenic Arabidopsis overexpressing STZ showed growth retardation and tolerance to drought stress. These results suggest that AZF2 and STZ function as transcriptional repressors to increase stress tolerance following growth retardation.
Divergent Potentials for Cytoplasmic Inheritance within the Genus Syringa. A New Trait Associated with Speciogenesis
Authors: Liu Yang , Cui Hongxia , Zhang Quan , Sodmergen
Published: September 2004

Epifluorescence microscopic detection of organelle DNA in the mature generative cell is a rapid method for determining the potential for the mode of cytoplasmic inheritance. We used this method to examine 19 of the known 22 to 27 species in the genus Syringa. Organelle DNA was undetectable in seven species, all in the subgenus Syringa, but was detected in the 12 species examined of the subgenera Syringa and Ligustrina. Therefore, species within the genus Syringa display differences in the potential cytoplasmic inheritance. Closer examination revealed that the mature generative cells of the species in which organelle DNA was detected contained both mitochondria and plastids, but cells of the species lacking detectable organelle DNA contained only mitochondria, and the epifluorescent organelle DNA signals from the mature generative cells corresponded to plastid DNA. In addition, semiquantitative analysis was used to demonstrate that, during pollen development, the amount of mitochondrial DNA decreased greatly in the generative cells of the species examined, but the amount of plastid DNA increased remarkably in the species containing plastids in the generative cell. The results suggest that all Syringa species exhibit potential maternal mitochondrial inheritance, and a number of the species exhibit potential biparental plastid inheritance. The difference between the modes of potential plastid inheritance among the species suggests different phylogenies for the species; it also supports recent conclusions of molecular, systematic studies of the Syringa. In addition, the results provide new evidence for the mechanisms of maternal mitochondrial inheritance in angiosperms.
Respecting the past
Authors: Rockman Ilene F.
Published: September 2004

Discusses the need for a new administrator to respect an organization's culture, past achievements, and key personnel. When this does not occur, it encourages employees to move on to new employment opportunities.
A university‐wide, library‐based chat service
Authors: Curtis Donnelyn , Greene Araby
Published: September 2004

The University of Nevada, Reno Library offers a general‐information “Chat with us” service through the university Web site in conjunction with the “Ask a librarian” service available through library Web pages. A study of 826 transcripts for the first academic year revealed that 80 percent of chat sessions originated from the university page. The majority of visitors were prospective students with questions related to admissions. Most of the chat operators believe the library should continue providing the university‐wide service. While university offices possess the information to answer many of the questions, librarians are skillful and patient when determining visitors' information needs, and were able to supply appropriate resources. Librarians were proactive in contacting university offices on behalf of chat visitors and provided e‐mail addresses, phone numbers, and URLs as needed. The continued collection and analysis of chat transcripts will help to determine the direction of library and university chat services.
Information competence as a value‐added product: applying the business model to academe
Authors: Vuotto Frank
Published: September 2004

This article details the process behind utilizing business models and concepts to create one of the most comprehensive subject‐specific information competence Web sites in the USA.