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Biomedical subjects

H Sass

Publications and source records attributed to H Sass.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Personality and personality disorders I. Universality and sensitivity of dimensional personality models as diagnostic systems for personality disorders].

OBJECTIVE: A dimensional diagnostic system for personality disorders (PD) postulates continuous transitions from normal to disordered personalities (continuity hypothesis) and universal validity of basic personality dimensions (universal hypothesis). In the present study three dimensional personality models that claim to provide a systematic representation of the overall domain of personality disorders were compared: the Big-Five model proposed by Costa and McCrae, the psychobiological model proposed by Cloninger and colleagues, and the "Dimensional Assessment of Personal Pathology (DAPP)" model proposed by Livesley and colleagues. METHOD: The "Six Factor Test" (SFT) measuring the Big-Five factors of personality, the "Temperament and Character Inventory (TCI)" measuring 4 temperament and 3 character dimensions, and the DAPP measuring 18 basic traits and 4 second ordered factors were administered to general population subjects (n = 156), and a clinical sample (n = 220) including a subsample of 69 patients with at least one diagnosis of DSM-IV PD. Group comparisons, regression analyses, and facet theoretical analyses were conducted. RESULTS: The nonmetric similarity analyses of the three personality models show a nearly identical radex-representation of the second ordered factors in the non-clinical and clinical sample reflecting an universal validity of 4 basic personality dimensions and confirming the universal hypothesis. In comparison with the BIG-Five concept and the psychobiological model the DAPP model seems to be more sensitive to differentiate PD patients from controls with a reclassification rate of 94.5 %. CONCLUSIONS: The Big-Five model, the DAPP and the TCI represent a substantially similar domain despite their different conceptualization. However, the DAPP was more sensitive to differences between PD patients and controls, offered a more comprehensive account of PD, and could differentiate the two groups more effectively.

Character↗
PubMed2002

[Personality and personality disorders II. The Specificity of the DAPP-model as a diagnostic system for personality disorders].

The 'Dimensional Assessment of Personality Pathology - Basic Questionnaire' (DAPP) measures 18 traits to provide a systematic representation of the overall domain of personality disorders (PD). The present study investigated the relationships between DAPP personality profiles and dimensional assessments of DSM-IV PD in general population subjects (n = 156), and a sample of 220 nonpsychotic psychiatric patients (including n = 67 PD patients). Using nonmetric multidimensional scaling models the similarities between the 18 DAPP-factors and the dimensional scores of the 12 DSM-IV PD (inclusive appendix) were graphically represented in a 2-dimensional similarity-system. Here each DSM-IV PD dimension could be described by a distinct profile of DAPP-factors. Overall results support the assumption that PD can be represented by a dimensional system of personality traits with sufficient sensitivity and specificity.

Humans↗
PubMed2002

Effects of the hallucinogen psilocybin on covert orienting of visual attention in humans.

Hallucinogenic drug-induced states are considered as models for acute schizophrenic disorders (experimental psychoses). In a double-blind study with healthy volunteers we investigated the influence of the serotonergic hallucinogen psilocybin, the ecstasy-like drug 3,4-methylenedioxyethylamphetamine (MDE), the stimulant d- methamphetamine and placebo on covert orienting of spatial attention (n = 8 in each group). Reaction times were prolonged after ingestion of psilocybin > MDE, but not after d-methamphetamine. In addition, subjects on psilocybin exhibited particularly slow reaction times in invalid trials at short cue target intervals and failure of response inhibition in valid trials at long cue target intervals for right visual field targets. Despite some methodological limitations, these results are in line with both bilateral impairment of disengagement of attention and a lateralized impairment of inhibition of return (IOR) in productive psychotic states. Additional investigations with larger samples, different hallucinogenic substances (serotonergic agonists vs. NMDA antagonists) and different dose regimens are needed in order to further explore the suggested relationship between visuospatial attentional dysfunction and acute psychotic conditions.

3,4-Methylenedioxyamphetamine↗
PubMed2001

Monoalkylether phospholipids in the sulfate-reducing bacteria Desulfosarcina variabilis and Desulforhabdus amnigenus.

In this study, cellular lipid compositions of two mesophilic sulfate-reducing bacteria were analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). In Desulfosarcina variabilis and Desulforhabdus amnigenus, alkylether-containing phospholipids were detected which had previously only been found in significant amounts in deeply branching hyperthermophilic bacteria and archaea. Combining information from HPLC-MS analysis and chemical degradation experiments, ether lipids were identified as 1-alkyl-2-acyl-phosphatidyl ethanolamines, glycerols and cholines. In Desulforhabdus amnigenus, n-penta-, n-hexa- and n-heptadecyl ethers were present (in order of decreasing abundance), whereas Desulfosarcina variabilis solely contained n-hexadecyl ether side chains.

Chromatography, High Pressure Liquid↗
PubMed2001

Evidence of abnormal amygdala functioning in borderline personality disorder: a functional MRI study.

BACKGROUND: Intense and rapidly changing mood states are a major feature of borderline personality disorder (BPD); however, there have only been a few studies investigating affective processing in BPD, and in particular no neurofunctional correlates of abnormal emotional processing have been identified so far. METHODS: Six female BPD patients without additional major psychiatric disorder and six age-matched female control subjects underwent functional magnetic resonance imaging (fMRI) to measure regional cerebral hemodynamic changes following brain activity when viewing 12 standardized emotionally aversive slides compared to 12 neutral slides, which were presented in random order. RESULTS: Our main finding was that BPD subjects but not control subjects were characterized by an elevated blood oxygenation level dependent fMRI signal in the amygdala on both sides. In addition, activation of the medial and inferolateral prefrontal cortex was seen in BPD patients. Both groups showed activation in the temporo-occipital cortex including the fusiform gyrus in BPD subjects but not in control subjects. CONCLUSIONS: Enhanced amygdala activation in BPD is suggested to reflect the intense and slowly subsiding emotions commonly observed in response to even low-level stressors. Borderline subjects' perceptual cortex may be modulated through the amygdala leading to increased attention to emotionally relevant environmental stimuli.

Affect↗
PubMed2001

Emotion in criminal offenders with psychopathy and borderline personality disorder.

BACKGROUND: Criminal offenders with a diagnosis of psychopathy or borderline personality disorder (BPD) share an impulsive nature but tend to differ in their style of emotional response. This study aims to use multiple psychophysiologic measures to compare emotional responses to unpleasant and pleasant stimuli. METHODS: Twenty-five psychopaths as defined by the Hare Psychopathy Checklist and 18 subjects with BPD from 2 high-security forensic treatment facilities were included in the study along with 24 control subjects. Electrodermal response was used as an indicator of emotional arousal, modulation of the startle reflex as a measure of valence, and electromyographic activity of the corrugator muscle as an index of emotional expression. RESULTS: Compared with controls, psychopaths were characterized by decreased electrodermal responsiveness, less facial expression, and the absence of affective startle modulation. A higher percentage of psychopaths showed no startle reflex. Subjects with BPD showed a response pattern very similar to that of controls, ie, they showed comparable autonomic arousal, and their startle responses were strongest to unpleasant slides and weakest to pleasant slides. However, corrugator electromyographic activity in subjects with BPD demonstrated little facial modulation when they viewed either pleasant or unpleasant slides. CONCLUSIONS: The results support the theory that psychopaths are characterized by a pronounced lack of fear in response to aversive events. Furthermore, the results suggest a general deficit in processing affective information, regardless of whether stimuli are negative or positive. Emotional hyporesponsiveness was specific to psychopaths, since results for offenders with BPD indicate a widely adequate processing of emotional stimuli.

Adult↗
PubMed2001

[The startle reflex in schizophrenia research].

Abnormalities of attention and information processing are described as important features of schizophrenia. Theoretically, they may reflect deficiencies in central mechanisms of inhibition and selection. These deficiencies are believed to lead to cognitive fragmentation in patients with schizophrenia. Findings of an impaired prepulse-inhibition (PPI) and habituation of the startle reflex in patients with schizophrenia are thought to represent preattentive, i.e., automatic attention deficits. Other paradigms with attentional instructions help to detect and to quantify deficits in controlled attentional functions. The PPI of the auditory startle blink reflex-mediated primarily by brainstem structures--is regulated by cortico-striato-pallido-pontine influences and by neurotransmitters involved in the pathogenesis of schizophrenia. An animal model of PPI provides the possibility to test neurobiological hypotheses in schizophrenia and to screen substances for their potential antipsychotic properties. Because reduction of PPI also occurs in other neuropsychiatric disorders, further studies are required to develop new paradigms of startle modification with findings of higher specificity and probable diagnostic relevance in patients with schizophrenia.

Acoustic Stimulation↗
PubMed2001

[Etiological and therapeutic aspects of schizoid and schizotypal personality disorder].

Following the introduction to the history of the concepts of abnormal personality, with regard to the schizoid and schizotypal forms, we present their systematic assessment in the modern classification systems.Both, the schizoid and schizotypal forms, are usually considered as schizophrenia-spectrum disorders. Biological and clinical data indicate relations to other axis-I disorders as well. However there are few systematic and strictly controlled studies on the psychotherapeutic and pharmacological treatment of schizotypal and schizoid personality disorders. Basic theoretic assumptions concerning both treatment concepts - for personality disorders in general, and especially in schizoid and schizotypal personality disorder - are given. Finally the role of neuroleptics and antidepressants for schizophrenia-spectrum disorders is discussed. New possibilities may emerge from the use of the recently developed atypical drugs, but further research in randomised studies is needed. Current prospective studies on early detected schizophrenia-spectrum disorders will broaden our knowledge about prevention and therapy.

Humans↗
PubMed2001

Psychophysiological responses in ADHD boys with and without conduct disorder: implications for adult antisocial behavior.

OBJECTIVE: Several studies have demonstrated that the presence of attention-deficit/hyperactivity disorder (ADHD) in childhood increases the risk of antisocial behavior developing in adulthood. However, because previous research did not consider comorbid conduct disorder (CD), the question of whether ADHD by itself or only the association of ADHD with CD implies a risk of adult antisocial behavior developing is still under discussion. METHOD: Because several characteristics of psychophysiological response had been shown to be associated with future increased likelihood of adult antisocial behavior, autonomic arousal as well as electrodermal responses to orienting and aversive stimuli were assessed in 26 boys with ADHD+CD compared with 21 boys with ADHD alone and 21 controls. RESULTS: Boys with a comorbid condition of ADHD+CD showed a decrement of autonomic responses and a more rapid habituation to orienting and aversive startling stimuli compared with age-matched children with ADHD alone. CONCLUSIONS: Boys with ADHD+CD show a psychophysiological response pattern that is very similar to that reported in antisocial personalities. These findings give further support for a high persistence of antisocial behavior from childhood to adulthood, while no evidence was found that ADHD itself is associated with a predisposition to antisocial behavior.

Adolescent↗
PubMed2001

Microbial communities in the chemocline of a hypersaline deep-sea basin (Urania basin, Mediterranean Sea).

The Urania basin is a hypersaline sulfidic brine lake at the bottom of the eastern Mediterranean Sea. Since this basin is located at a depth of approximately 3,500 m below the sea surface, it receives only a small amount of phytoplankton organic carbon. In the present study, the bacterial assemblages at the interface between the hypersaline brine and the overlaying seawater were investigated. The sulfide concentration increased from 0 to 10 mM within a vertical interval of 5 m across the interface. Within this chemocline, the total bacterial cell counts and the exoenzyme activities were elevated. Employing 11 cultivation methods, we isolated a total of 70 bacterial strains. The 16S ribosomal DNA sequences of 32 of the strains were identical to environmental sequences detected in the chemocline by culture-independent molecular methods. These strains were identified as flavobacteria, Alteromonas macleodii, and Halomonas aquamarina. All 70 strains could grow chemoorganoheterotrophically under oxic conditions. Sixty-six strains grew on peptone, casein hydrolysate, and yeast extract, whereas only 15 strains did not utilize polymeric carbohydrates. Twenty-one of the isolates could grow both chemoorganotrophically and chemolithotrophically. While the most probable numbers in most cases ranged between 0.006 and 4.3% of the total cell counts, an unusually high value of 54% was determined above the chemocline with media containing amino acids as the carbon and energy source. Our results indicate that culturable bacteria thriving at the oxic-anoxic interface of the Urania basin differ considerably from the chemolithoautotrophic bacteria typical of other chemocline habitats.

Colony Count, Microbial↗
PubMed2000

Introduction to this issue: international perspectives on psychopathic disorders.

The importance of characterological disturbances, that contribute towards individual patterns of law breaking behavior, to legal systems in all countries should be self-evident. Contributors to this international perspective issue represent Canada, Germany, Great Britain, and the United States, and data from several additional European countries were included in Hare's article. This issue addresses emotional deficiency, molecular genetics, construct and predictive validity of the PCL-R, psychosocial predictors and treatment. Critical analyses of current models for civil commitment and criminal responsibility vis-à-vis psychopathic disorders contribute towards informed dialectic on these compelling public policy issues. We hope that readers will find that these articles collectively advance our understanding of the nature of these disorders, currently available therapeutic interventions, and today's critical social issues.

Affect↗
PubMed2000

Emotional deficiency and psychopathy.

Aside from an antisocial life-style, the concept of psychopathy is based on character features which can be described in terms of specific patterns of interpersonal, behavioral, and, in particular, affective characteristics. Concluding from studies which have dealt with the affective domain in psychopaths, emotional deficiency may predispose to violence in several ways. (1) Poor conditioning implicates a failure to review the harmful consequences of one's actions leading to a deficit of avoidance behavior. (2) Emotional detachment prevents experiencing feelings, which naturally inhibit the acting out of violent impulses. (3) Emotional deficiency is closely associated with a general underarousal, leading to sensation seeking. Current data suggest that there may be a close association between difficulties in emotional processing and poor prefrontal functioning. From a psychosocial perspective, psychopaths were shown to have been exposed to severe familial and societal difficulties. Whether biological or environmental factors dominate in the etiology of this personality disorder, psychopathy does not per se justify the assumption of decreased legal responsibility.

Affect↗
PubMed2000

[External quality assurance of inpatient treatment in schizophrenia. results of a multicenter study].

Due to legal regulations, external quality assurance is mandatory in Germany. Supported by the German Health Ministry (BMG), we present the results of a multicenter study in four hospitals with different structures on 1042 inpatients with the tracer diagnosis of schizophrenia (ICD 10). We defined disease-specific indicators of structure, process, and outcome quality, developed an assessment instrument, and implemented a feedback system for quality comparison. The resulting quality profiles are useful as a starting point for internal quality management.

Acute Disease↗
PubMed2000

[The internet as a delusional topic in paranoid schizophrenia].

Two patients with paranoid schizophrenia had delusions involving the internet. Additionally, one of them experienced computer databases as being distributed to other people in a phenomenologically similar way to that encountered in thought broadcasting. The presented cases illustrate the historical association of the contents of delusions in schizophrenia.

Adult↗
PubMed2000

High intensity dependence of auditory evoked dipole source activity indicates decreased serotonergic activity in abstinent ecstasy (MDMA) users.

Neurotoxic damage of central serotonergic systems has been demonstrated in numerous animal studies after exposure to methylenedioxyamphetamines (ecstasy). A high intensity dependence of auditory evoked potentials and, particularly, of the tangential N1/P2 source activity has been associated with low levels of serotonergic neurotransmission in humans. We performed an auditory evoked potentials study in 28 abstinent recreational ecstasy users and two equally sized groups of cannabis users and nonusers. The ecstasy users exhibited an increase of the amplitude of the tangential N1/P2 source activity with higher stimulus intensities; whereas, both control groups failed to exhibit this feature. These data are in line with the hypothesis that abstinent ecstasy users present with diminished central serotonergic activity. This feature of information processing is probably related to the well-recognized neurotoxic potential of ecstasy. Our data indicate that recreational ecstasy use may cause long-term alterations in the function (and possibly structure) of the human brain.

Adolescent↗