Publications by authors named "Uri Loewenthal"

Background: Early life exposure to potentially traumatic experiences (PTEs) significantly increases the risk of responding more severely to stressful events experienced in adulthood. The aim of this study was to assess the autonomic nervous system (ANS) response to exposure to two PTEs in youth and again in adulthood, in terms of heart rate and heart rate variability in animals that responded to the PTE dramatically as compared to those that displayed virtually no behavioral response and to control animals.

Methods: The prevalence of individuals displaying extreme anxiety-like behavioral responses to the PTE (predator urine or elevated platform) was assessed in the elevated plus-maze and startle response paradigms.

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Background: Paradoxical changes in memory represent a troublesome characteristic of posttraumatic stress disorder (PTSD). Exceptionally vivid intrusive memories of some aspects of the trauma are mingled with patchy amnesia regarding other important aspects. Molecular studies of the memory process suggest that the conversion from labile short-term memory into long-term fixed traces involves protein synthesis.

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This study examined the effects of stress exposure on plasma levels of corticosterone, dehydroepiandrosterone (DHEA) and its sulphate derivative DHEA-S in relation to behavioural responses. The magnitude of anxiety-like behaviours on the elevated plus-maze and of non-habituated exaggerated startle reactions were assessed in rats exposed to stress compared to controls. Individuals displaying extreme behavioural changes were termed extreme behavioural response (EBR), as opposed to minimal behavioural response (MBR) in both paradigms performed consecutively.

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Background: Posttraumatic stress disorder (PTSD) is associated with low levels of circulating cortisol, and recent studies suggest that cortisol administration may reduce PTSD symptoms. This study investigated the role of cortisol in the manifestation of anxiety- and fear-like symptoms in an animal model of PTSD.

Method: Magnitude of changes in prevalence of anxiety-like behaviors on the elevated plus-maze and nonhabituated exaggerated startle reaction were compared in three strains of rats exposed to predator stress, with and without prior corticosterone treatment.

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Background: In the era of deinstitutionalization, increasing numbers of schizophrenia patients reside and receive rehabilitational treatment within the framework of community hostels. The quality of staff-patient relationships is a crucial determinant of the rehabilitational process outcome.

Method: This study examined the characteristics of 56 schizophrenia hostel residents, measured the degree of staff criticism and rejection expressed towards these patients and assessed the contribution of residents and staff characteristics to the induction of staff rejection.

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Despite the well-known association between the hypothalamic-pituitary-adrenal (HPA) axis and normal fear, it is still unclear (a) to what extent corticotropin releasing hormone (CRH) or cortisol itself mediates fear responses, and (b) to what extent the HPA axis also affects panic disorder. The carbon-dioxide (CO2) challenge has been proposed as a model for panic. Participants received the cortisol synthesis inhibitor metyrapone 30 mg/kg of body weight once and placebo once, with 1 week between challenges, at 2300 h.

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Despite the effectiveness of antipsychotic medications in treatment of schizophrenia, about 30% of patients who receive an adequate treatment have significant persisting symptoms. The problem of treatment-resistant psychosis is an important and difficult one. The aim of this study was to retrospectively evaluate the efficacy and safety of amisulpride augmentation in treatment-resistant schizophrenic patients.

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Post-traumatic stress disorder (PTSD) affects about 20-30% of exposed individuals. Clinical studies of PTSD generally employ stringent criteria for inclusion in study populations, and yet in animal studies the data collection and analysis are generally expressed as a function of exposed vs nonexposed populations, regardless of individual variation in response. Prior data support an approach to animal models analogous to inclusion criteria in clinical studies.

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Background: Vitamin B6, or pyridoxine, plays an intrinsic role in the synthesis of certain neurotransmitters that take part in development of psychotic states. Several reports indicate that vitamin B6 may be a factor in a number of psychiatric disorders and related conditions, such as autism, Alzheimer's disease, hyperactivity, learning disability, anxiety disorder, and depression. Moreover, there are anecdotal reports of a reduction in psychotic symptoms after vitamin B6 supplementation of psychopharmacologic treatment of patients suffering from schizophrenia or organic mental disorder.

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