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Biomedical subjects

L Trevisan

Publications and source records attributed to L Trevisan.

12 recordsLinked to original sources
PubMed2001

Effect of tryptophan depletion on alcohol cue-induced craving in abstinent alcoholic patients.

BACKGROUND: The capacity of alcohol cues to precipitate the desire to drink may be an important determinant of relapse to alcohol use in recovering alcohol-dependent patients. This study evaluated whether attenuation of serotonin synthesis via depletion of its precursor tryptophan reduces the magnitude of cue-induced craving for alcohol in recently abstinent alcoholic individuals. METHODS: Alcohol-dependent patients (n = 16), 1 to 3 months after detoxification, who exhibited a 20% or greater increase in reported craving when presented with an alcoholic beverage, completed two additional alcohol cue-exposure test days, 1 week apart. Each cue exposure was preceded by administration of a concentrated amino acid drink that resulted in a rapid and significant decline in plasma free tryptophan (active depletion, no tryptophan supplementation) or a similar drink containing tryptophan (placebo depletion). Tests were conducted in a randomized, double-blind fashion. RESULTS: There were no significant changes in the magnitude of cue-induced craving with active tryptophan depletion compared with placebo. CONCLUSIONS: These data question the dependence of alcohol cue-induced craving in sober alcoholics on the ongoing synthesis of serotonin.

Adult↗
PubMed1999

CSF monoamine metabolite and beta endorphin levels in recently detoxified alcoholics and healthy controls: prediction of alcohol cue-induced craving?

BACKGROUND: Abnormalities in central neurotransmitter systems have been described in alcohol-dependent individuals and may contribute to alcohol craving. This study compared cerebrospinal fluid (CSF) levels of monoamine metabolites and beta endorphin levels in samples from early-onset alcohol-dependent patients (n = 20), late-onset alcohol-dependent patients (n = 14), and healthy controls (n = 23). It also evaluated whether these CSF measures levels predicted the degree of craving experienced in response to an alcohol cue. METHODS: Individuals meeting DSM-III and -IV R-criteria for alcohol dependence, 1 to 3 months postdetoxification, and healthy controls underwent a lumbar puncture. Patients also completed a cue exposure test day between 3 and 15 days later. RESULTS: Alcohol-dependent patients had lower CSF levels of the norepinephrine metabolite MHPG compared with the healthy subjects, but this difference disappeared when differences in age between the groups were accounted for. No other group comparisons between patients and healthy subjects reached significance. CSF levels of the dopamine metabolite HVA were significantly higher in the early-onset patients compared with the late-onset patients and controls. The CSF measures did not predict the precue levels of craving, or the increase in craving after alcohol cue exposure. CONCLUSIONS: These results are inconclusive about the role of monoaminergic dysregulation in recovering alcoholics. They also question the utility of these CSF measures to predict alcohol cue reactivity in patients who have been sober at least 1 month.

Adult↗
PubMed1995

Biochemical actions of chronic ethanol exposure in the mesolimbic dopamine system.

In previous studies, we have demonstrated that chronic administration of morphine or cocaine produces some common biochemical adaptations in the ventral tegmental area (VTA) and nucleus accumbens (NAc), components of the mesolimbic dopamine system implicated in the reinforcing actions of these and other drugs of abuse. Since this neural pathway is also implicated in the reinforcing actions of ethanol, it was of interest to determine whether chronic ethanol exposure results in similar biochemical adaptations. Indeed, as seen for chronic morphine and cocaine treatments, we show here that chronic ethanol treatment increased levels of tyrosine hydroxylase and glial fibrillary acidic protein immunoreactivity, and decreases levels of neurofilament protein immunoreactivity, in the VTA. Also like morphine and cocaine, ethanol increases levels of cyclic AMP-dependent protein kinase activity in the NAc. These actions of ethanol required long-term exposure to the drug, and were in most cases not seen in the substantia nigra or caudateputamen, components of the nigrostriatal dopamine system studied for comparison. Altered levels of tyrosine hydroxylase in catecholaminergic cells frequently reflect altered states of activation of the cells. Moreover, increasing evidence indicates that ethanol produces many of its acute effects on the brain by regulating NMDA glutamate and GABAA receptors. We therefore examined the influence of chronic ethanol treatment on levels of expression of specific glutamate and GABA receptor subunits in the VTA. It was found that long-term, but not short-term, ethanol exposure increased levels of immunoreactivity of the NMDAR1 subunit, an obligatory component of NMDA glutamate receptors, and of the GluR1 subunit, a component of many AMPA glutamate receptors; but at the same time, long-term ethanol exposure decreased immunoreactivity levels of the alpha 1 subunit of the GABAA receptor complex. These changes are consistent with an increased state of activation of VTA neurons inferred from the observed increase in tyrosine hydroxylase (TH) expression. These results demonstrate that chronic ethanol exposure results in several biochemical adaptations in the mesolimbic dopamine system, which may underlie prominent changes in the structural and functional properties of this neural pathway related to alcohol abuse and alcoholism.

Adenylyl Cyclases↗
PubMed1994

Chronic ingestion of ethanol up-regulates NMDAR1 receptor subunit immunoreactivity in rat hippocampus.

We examined the effects of chronic ethanol exposure on the levels of N-methyl-D-aspartate receptor subunit 1 (NMDAR1) protein, an essential component of N-methyl-D-aspartate glutamate receptors, in rat brain. By immunoblotting procedures using a specific antibody for the NMDAR1 subunit, we found that ethanol dramatically up-regulated (by 65%) NMDAR1 immunoreactivity in the hippocampus but not in the nucleus accumbens, cerebral cortex, or striatum. In contrast, ethanol did not alter the levels of glutamate receptor subunit (GLUR) 1 or GLUR2 protein, subunits that make up the alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid glutamate receptor, in the hippocampus. Because ethanol can potentially influence many different neurotransmitter systems, we examined whether chronic treatment with several psychotropic drugs with different pharmacological profiles (cocaine, haloperidol, SCH 23390, imipramine, and morphine) could mimic the effect of ethanol. None of these agents increased hippocampal NMDAR1 subunit immunoreactivity after chronic administration. Increased NMDAR1 subunit levels in the hippocampus after chronic ethanol exposure may represent an important neurochemical substrate for some of the features associated with ethanol dependence and withdrawal.

Alcoholism↗
PubMed1991

Anabolic steroid education and adolescents: do scare tactics work?

The opinions (level of agreement) of high school varsity football players with regard to reported effects of anabolic steroids were assessed before and after two different education interventions. Lectures and handouts of a balanced education program (potential risks and benefits) were compared with a risks-only (negative or "scare tactics") presentation, in a controlled manner. Those receiving the balanced review significantly increased their agreement with 5 of 10 targeted adverse effects, while no change occurred for any risks among those taught by the negative intervention. A teaching model that only emphasizes the untoward consequences of anabolic steroids is ineffective, even in the short-term. A balanced education approach can improve understanding of the potential adverse effects of these drugs. Additional strategies may be required to change young athletes' attitudes toward anabolic androgenic steroid use.

Adolescent↗
PubMed1990

Effect of an anabolic steroid education program on knowledge and attitudes of high school football players.

Six varsity high school football teams were assessed by confidential questionnaire regarding anabolic steroids, before and 2 weeks after an education intervention. The education program used the American College of Sports Medicine's position on the "use of anabolic androgenic steroids in sports." Two teams received a lecture and a four-page handout, two teams were given the handout only, and two teams were controls. Self-report of current use was 1.1% but 38.8% claimed availability of these agents. Although increased awareness of the adverse effects of anabolic steroid was found after the education program, no differences in attitudes toward the use of anabolic steroids occurred as compared to controls. Strategies designed to dissuade adolescent athletes from considering these drugs need to be developed.

Adolescent↗
PubMed1984

Induction of sister-chromatid exchanges in human lymphocytes exposed in vitro and in vivo to therapeutic ultrasound.

The induction of sister-chromatid exchanges (SCEs), chromosomal aberrations and cell-cycle delay was determined in human lymphocytes after treatment in vitro and in vivo with therapeutic ultrasound (u.s.). In vitro treatments (1 W/cm2; 0.860 MHz; for 40-160 sec) were performed on unstimulated lymphocytes from 9 donors: a statistically significant, dose-dependent increase in SCE frequency was produced, whereas no induction of chromosomal aberrations nor alteration of the distribution of 1st, 2nd and 3rd division metaphases were observed. The same increase in the frequency of SCEs was detected by treating in vitro stimulated lymphocytes with u.s. The effects of in vivo exposure to u.s. were detected on lymphocytes from 10 patients before, during and after u.s. therapy (0.6-1.0 W/cm2; 0.860 MHz; from 8 to 20 applications lasting 5-6 min each). SCE frequency was statistically significantly increased in all patients at mid-therapy, without a further increase during the second half of therapeutic cycle, and was restored to pretreatment level 3 months after the end of u.s. therapy. No increase in chromosomal aberrations was noticed during and after u.s. therapy, whereas erratic delays of the cell cycle were observed, not clearly related to u.s. application or SCE levels. A linear relationship was found between SCE frequency and age in 21 healthy donors.

Cell Cycle↗
PubMed1976

Derivatives of 2H,3H-benzimidazo(1,2-b)oxazole.

The Authors report the synthesis and chemical properties of a number of derivatives of 2H,3H-benzimidazo(1,2-b)oxazole. These substances were prepared in order to investigate their pharmacological activity.

Benzimidazoles↗