559 research outputs found
Effect of different agonistic experiences on behavioural seizures in fully amygdala kindled rats
Fully amygdala kindled rats were exposed to two different inter-male agonistic experiences in order to study the interaction between epilepsy and acute social stress. Victory experience did not influence the severity of seizure behaviour, whereas a single acute defeat modified both ictal and postictal seizure manifestations. Defeat resulted in less severe and shorter lasting motor seizures, and the accompanied postictal inhibition or behavioural depression was of shorter duration in comparison with pre-stress values. The ability of acute defeat to trigger anticonvulsant activity as implied by the weakened convulsive response is discussed.
Differential Effects of Neonatal Testosterone Treatment on Aggression in Two Selection Lines of Mice
Selection lines of mice, artificially selected for aggression based upon the attack latency score (ALS), were used. In order to determine the relative contribution of neonatal testosterone (T) in the development of aggression, we vary the plasma-T level in males of both selection lines on the day of birth. At 14 weeks the ALS was measured. Neonatal T treatment results in a reduction of aggression in the long attack latency (LAL) line, whereas aggressive behaviour of the short attack latency (SAL) line is not affected. Both selection lines show reduction in testicular weight, although the total amount of T-producing Leydig cells was not affected. Neonatal T may cause a permanent reduction in aggressive behaviour in the LAL line only, probably due to differential appearance of critical periods. It is suggested that the difference in aggressive behaviour between SAL and LAL selection lines is due to a prenatally determined difference in neonatal T sensitivity of the brain.
Temporal and spatial dynamics of corticosteroid receptor down-regulation in rat brain following social defeat
The experiments explored the nature and time course of changes in glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) binding in homogenates of various brain regions and pituitary of male Wistar rats following social defeat stress. One week after defeat, the binding capacity of GRs was decreased in the hippocampus and the hypothalamus while no changes were observed in the parietal cortex and the pituitary. The number of MRs remained at the same level as in undefeated rats. Three weeks postdefeat, the initially down-regulated GR returned to baseline level in the hippocampus and the hypothalamus. However, GR binding was now decreased in the parietal cortex. Severe down-regulation of MRs was detected in the hippocampal and septal tissue. The results show that brief but intense stress like social defeat induces a long-lasting down-regulation of corticosteroid receptors and that the temporal dynamics of these changes are not only differential for GRs and MRs but also for brain sites.
ESCAP Expert Article: Borderline personality disorder in adolescence: An expert research review with implications for clinical practice
Borderline personality disorder (BPD) has onset in adolescence, but is typically first diagnosed in young adulthood. This paper provides a narrative review of the current evidence on diagnosis, comorbidity, phenomenology and treatment of BPD in adolescence. Instruments available for diagnosis are reviewed and their strengths and limitations discussed. Having confirmed the robustness of the diagnosis and the potential for its reliable clinical assessment, we then explore current understandings of the mechanisms of the disorder and focus on neurobiological underpinnings and research on psychological mechanisms. Findings are accumulating to suggest that adolescent BPD has an underpinning biology that is similar in some ways to adult BPD but differs in some critical features. Evidence for interventions focuses on psychological therapies. Several encouraging research studies suggest that early effective treatment is possible. Treatment development has just begun, and while adolescent-specific interventions are still in the process of evolution, most existing therapies represent adaptations of adult models to this developmental phase. There is also a significant opportunity for prevention, albeit there are few data to date to support such initiatives. This review emphasizes that there can be no justification for failing to make an early diagnosis of this enduring and pervasive problem
Simulation of Dose Estimations from Solar Protons: A PMMA-Bi2O3 Shielding Model for Space Exploration
Adverse effects of long-term exposure to galactic cosmic radiation (GCR) pose a non negligible obstacle for future space exploration programs; the high-LET-particle-rich environment has an adverse effect on human health. Concomitant to GCR we have as well solar particle radiation. Long term space exploration will rely on adequate and highly efficient shielding materials that will reduce exposure of both biosystems and electronic equipment to GCR and solar particles. The shield must attenuate efficiently heavy GCR ions, by breaking them up into less-damaging fragments and secondary radiation: biologically damaging energetic neutrons and highly charged and energetic HZE- particles. An approach to this problem is the development of shielding compounds. Shielding materials should address the conditions of different aspects of a given mission, e.g. time duration and travel path. The Monte Carlo method (GEANT4) is here employed to estimate the effects of a shielding material based on the recently developed Bi2O3-based compound (Cao et al., 2020). In the present study GEANT4 code is used to make estimations of attenuation of solar protons. The objective is to provide some insight about the effect of the new composite shield that has an intrinsic capability for dose reduction
Ruthenium-catalyzed solvent-free conversion of furfural to furfuryl alcohol
Bidentate phosphine-modified Ru-based homogeneous catalyst systems were developed for solvent-free conversion of furfural to furfuryl alcohol as a versatile biomass-based C5-platform molecule. The effect of ligand structure, ligand concentration, operating pressure and reaction temperature on the catalyst's activity were studied in details. Under optimized conditions complete conversion of furfural to furfurol was achieved in the absence of any solvent and without by-product formation. The maximum turnover frequency (6273 h–1) and 100% atom economy were obtained by using homogeneous Ru/Ph2P(CH2)4PPh2 catalyst, which was recyclable for twelve consecutive runs without affecting catalytic performance of the catalyst
PADC-NTM Applied in 7Li+Pb at 31 MeV Reaction Products Study
Passive nuclear track methodology (NTM) is applied to study charged particles products of the reaction 7Li+Pb at ~ 31 MeV. It is a contribution to the 8pLP Project (LNL-INFN-Italy) in where we show an alternative approach to register charged particle from reaction fragments by PADC detection. The main advantage is that the passive system integrates data over the whole experiment and has its importance for low rate reaction processes. Reaction products as well as scattered beam particles are determined from track shape analysis. Some limitations are inherent to NTM since a priori knowledge is required to correlate track size distribution given by each type of particle emerging from the target. Results show that the passive technique gives useful information when applied in reaction data interpretation for a relatively large range of particle types
Physical Exercise Training versus Relaxation in Allogeneic stem cell transplantation (PETRA Study) – Rationale and design of a randomized trial to evaluate a yearlong exercise intervention on overall survival and side-effects after allogeneic stem cell transplantation
Background: Allogeneic stem cell transplantation (allo-HCT) is associated with high treatment-related mortality and innumerable physical and psychosocial complications and side-effects, such as high fatigue levels, loss of physical performance, infections, graft-versus-host disease (GvHD) and distress. This leads to a reduced quality of life, not only during and after transplantation, but also in the long term. Exercise interventions have been shown to be beneficial in allo-HCT patients. However, to date, no study has focused on long-term effects and survival. Previous exercise studies used ‘usual care’ control groups, leaving it unclear to what extent the observed effects are based on the physical effects of exercise itself, or rather on psychosocial factors such as personal attention. Furthermore, effects of exercise on and severity of GvHD have not been examined so far. We therefore aim to investigate the effects and biological mechanisms of exercise on side-effects, complications and survival in allo-HCT patients during and after transplantation. Methods/design: The PETRA study is a randomized, controlled intervention trial investigating the effects of a yearlong partly supervised mixed exercise intervention (endurance and resistance exercises, 3–5 times per week) in 256 patients during and after allogeneic stem cell transplantation. Patients in the control group perform progressive muscle relaxation training (Jacobsen method) with the same frequency. Main inclusion criterion is planned allo-HCT. Main exclusion criteria are increased fracture risk, no walking capability or severe cardiorespiratory problems. Primary endpoint is overall survival after two years; secondary endpoints are non-relapse mortality, median survival, patient reported outcomes including cancer related fatigue and quality of life, physical performance, body composition, haematological/immunological reconstitution, inflammatory parameters, severity of complications and side-effects (e.g. GvHD and infections), and cognitive capacity. Discussion: The PETRA study will contribute to a better understanding of the physiological and psychological effects of exercise training and their biological mechanisms in cancer patients after allo-HCT. The ultimate goal is the implementation of optimized intervention programs to reduce side-effects and improve quality of life and potentially prognosis after allogeneic stem cell transplantation. Trial registration: ClinicalTrials.gov Identifier: NCT0137439
Improved emotion regulation after neurofeedback: A single-arm trial in patients with borderline personality disorder
Real-time functional magnetic resonance imaging (fMRI) neurofeedback training of amygdala hemodynamic activity directly targets a neurobiological mechanism, which contributes to emotion regulation problems in borderline personality disorder (BPD). However, it remains unknown which outcome measures can assess changes in emotion regulation and affective instability, associated with amygdala downregulation in a clinical trial. The current study directly addresses this question. Twenty-four female patients with a DSM-IV BPD diagnosis underwent four runs of amygdala neurofeedback. Before and after the training, as well as at a six-weeks follow-up assessment, participants completed measures of emotion dysregulation and affective instability at diverse levels of analysis (verbal report, clinical interview, ecological momentary assessment, emotion-modulated startle, heart rate variability, and fMRI). Participants were able to downregulate their amygdala blood oxygen-dependent (BOLD) response with neurofeedback. There was a decrease of BPD symptoms as assessed with the Zanarini rating scale for BPD (ZAN-BPD) and a decrease in emotion-modulated startle to negative pictures after training. Further explorative analyses suggest that patients indicated less affective instability, as seen by lower hour-to-hour variability in negative affect and inner tension in daily life. If replicated by an independent study, our results imply changes in emotion regulation and affective instability for several systems levels, including behavior and verbal report. Conclusions are limited due to the lack of a control group. A randomized controlled trial (RCT) will be needed to confirm effectiveness of the training
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