839 research outputs found
Chronological relationship between antisocial personality disorder and alcohol dependence
Personality disorders, and particularly antisocial personality disorder (ASPD), frequently co-occur with alcohol dependence. ASPD is considered to be an important cofactor in the pathogenesis and clinical course of alcohol dependence. The chronological relationship between the onset of symptoms of ASPD and alcohol-dependence characteristics has not yet been studied in great detail and the role of ASID in classification schemes of alcohol dependence as suggested by Cloninger and Schuckit has yet to be determined. We studied 55 alcohol-dependent patients to assess the prevalence and age at manifestation of ASPD, conduct disorder characteristics as well as alcohol dependence by employing the Semi-Structured Assessment for the Genetics of Alcoholism and the Structured Clinical Interview for DSM-IIIR. Results indicate that the onset of ASPD characteristics precede that of alcohol dependence by some 4 years. This finding suggests that in patients with ASPD, alcohol dependence might be a secondary syndrome as suggested by previous research. Copyright (C) 2002 S. Karger AG, Basel
Correlated band structure and the ground-state phase diagram in high-Tc cuprates
We review results obtained with a recently proposed variational cluster
approach (VCA) for the competition between d-wave superconductivity (dSC) and
antiferromagnetism (AF) in the high-Tc cuprates. Comparing the single-particle
spectra of a two-dimensional Hubbard model with quantum Monte-Carlo (QMC) and
experimental data, we verify that the VCA correctly treats the low-energy
excitations. The cluster calculations reproduce the overall ground-state phase
diagram of the high-temperature superconductors both for electron- and
hole-doping. In particular, they include salient features such as the enhanced
robustness of the AF state in case of electron doping. For electron- but also
for hole-doping, we clearly identify a tendency to phase separation into a
mixed AF-dSC phase at low and a pure dSC-phase at high doping.Comment: 4 pages, 3 figures, submitted to the SCES'0
Impulsive traits and 5-HT2A receptor promoter polymorphism in alcohol dependents: Possible association but no influence of personality disorders
Objective: Impulsive behavior in alcoholics puts them at serious risk of severer course of disease and has been related to the serotonergic neurotransmission dysfunction. The aim of this study is to investigate the association between impulsive aggression in alcohol dependents with regard to the G-1438A polymorphism in the promoter region of the 5-HT2A receptor gene. Furthermore, we investigated the statistical interaction between 5-HT2A alleles, antisocial personality disorder (APD) and impulsive aggression in alcohol dependents. Alcohol dependents were investigated because these personality disorders and impulsive behavior are very frequent in alcohol dependence anf of clinical relevance. Methods: One hundred and thirty-five patients of German descent meeting DSM-IV criteria of alcohol dependence were recruited. Blood samples were taken from alcohol dependents to determine 5-HT2A promoter polymorphisms using PCR (polymerase chain reaction) of lymphocyte DNA. Impulsive aggression was assessed using a German version of the Barratt Impulsiveness Scale which was translated and backtranslated. Alcohol dependents were subdivided into low- or high-impulsivity groups using a median split of the Barratt score. APD and borderline personality disorder (BPD) were assessed using the SCID-II interview. Results: The low-impulsivity group was slightly older and showed a later age at alcoholism onset than the highly impulsive group. Alcohol dependents with high impulsive traits showed a significant association with 5-HT2A 1438 A alleles. After excluding alcohol dependents with APD or BPD from the analysis, this association remained significant. Furthermore, no association between APD, BPD and 5-HT2A alleles was noted. Conclusions: Inpatient alcohol dependents showed a significant association between 5-HT2A A alleles and impulsive traits, independent of the presence of APD or BPD. No association was noted between personality disorders and the polymorphism. This is the first report about an association of 5-HT2A promoter polymorphism and impulsive behavior in alcohol dependents. This finding may refer only to impulsive traits and may be independent of personality disorders in this sample. These results have to be confirmed in larger samples and in healthy control subjects to determine whether this association is of general validity. Copyright (C) 2001 S. Karger AG, Basel
Platelet monoamine oxidase activity in alcoholics with and without a family history of alcoholism
A number of studies point at platelet monoamine oxidase (MAO) activity being reduced in alcoholics with a family history of drinking, this being a possible vulnerability marker for alcoholism. To test this hypothesis, we examined a group of recently detoxified alcoholics with high (n = 25) and low genetic loading for alcoholism (n = 28) and a group of healthy controls (n = 21). Clinical assessments were made using the SCID II interview for psychiatric disorders, the Family History Assessment Module and the Semi-Structural Assessment of Genetics in Alcoholism, a questionnaire especially designed for genetic studies. Platelet MAO activity with and without ethanol stimulation and the percentage of MAO activity with ethanol did not differ between groups. The only significant difference was a lower inhibition of MAO activity with ethanol in alcoholics both with and without a family history compared to controls. In patients with antisocial personality traits, platelet MAO activity was also not found to be different from other alcoholics. Our findings question the hypothesis of reduced platelet MAO activity to be a possible vulnerability marker for alcoholism. Copyright (C) 2000 S. Karger AG. Basel
A method for accurate texture determination of thin oxide films by glancing-angle laboratory X-ray diffraction
The present article describes a modification to the standard method of glancing-angle X-ray diffraction for accurate measurement of the texture of thin oxide films. The technique resolves the problems caused by overlapping diffraction peaks originating from multiphase materials with asymmetric unit cells and the peak broadening associated with sample tilt during glancing-angle texture measurement. The entire 2θ range of interest is recorded as a function of sample orientation, and the integrated intensities from different crystallographic planes are extracted from fitted diffraction profiles. The technique allows for pole figures to be plotted from diffraction peaks that could otherwise not be resolved and separates contributions from neighbouring peaks, leading to a more accurate representation of the existing oxide texture. The proposed method has been used for determining texture in a 3 µm layer of monoclinic/tetragonal zirconium oxide grown during aqueous corrosion testing and has been verified by additional synchrotron X-ray diffraction measurements.</jats:p
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