Hypersensitive cell death in plants : its mechanisms and role in plant defense against pathogens

This review is a recent update in the understanding of the hypersensitive response (HR) of plants with special consideration to the physiological and biochemical determinants in different model systems. Hypersensitive response is reviewed as a form of programmed cell death (PCD) representing one of the mechanisms of plant defence against diseases. Major signalling pathways and molecules that accompany the HR, such as proteolytic cascades, oxidative events and ethylene that are supposed to play a key role in the plant¿s cell death machinery are discussed. Special attention is paid to the HR in fruit species. Studies on plant PCD are shown to provide a clue to better understanding disease resistance processes in plants and to establish the evolutionary aspects of PCD similarities through animal and plant kingdoms

Heterogeneity in Disordered Gambling: Decision-Making and Impulsivity in Gamblers Grouped by Preferred Form

Background: Previous research has indicated that disordered gamblers display deficits in impulsivity and risky decision-making, compared to healthy control groups. However, disordered gamblers are not a homogenous group, and differences in performance on neurocognitive tasks may be related to the form of gambling in which an individual chooses to engage. The present study used neurocognitive tasks and questionnaire measures to ascertain group differences in gamblers grouped by preferred form of gambling. Method: Treatment-seeking pathological gamblers from the National Problem Gambling Clinic, London (n=101) completed a neurocognitive assessment comprising the Cambridge Gamble Task (CGT), the Stop Signal Task (SST), a Probabilistic Reversal Learning task (PRL) and the Kirby Monetary Choice Questionnaire, as well as questionnaire measures of gambling severity, impulsivity, depression and anxiety. Analyses compared gamblers who favored Fixed Odds Betting Terminals (FOBTs) (the modal form) to gamblers who preferred other forms of gambling (non-FOBT). Results: The FOBT group showed impaired decision-making under risk on the CGT compared to the non-FOBT group, choosing the likely option less on more uncertain decisions. The FOBT group made fewer perseverative errors on the PRL task, had lower depression and anxiety scores, and were less likely to have a family history of problem gambling than the non-FOBT group. Discussion: Decision-making and cognitive flexibility differences between gamblers grouped by gambling type supports preferred form as an important source of heterogeneity in Gambling Disorder. Decision making strategies and risk attitudes should be considered when approaching cognition-focused treatment strategies, allowing interventions to be targeted at specific cognitive deficits

Influence of auxin and its polar transport inhibitor on the development of somatic embryos in Digitalis trojana

The present study reports the role of auxin and its transport inhibitor during the establishment of an efficient and optimized protocol for the somatic embryogenesis in Digitalis trojana Ivan. Hypocotyl segments (5 mm long) were placed vertically in the Murashige and Skoog medium supplemented with three sets [indole-3-acetic acid (IAA) alone or 2,3,5-triiodobenzoic acid (TIBA) alone or IAA-TIBA combination] of formulations of plant growth regulators, to assess their differential influence on induction and proliferation of somatic embryos (SEs). IAA alone was found to be the most effective, at a concentration of 0.5 mg/l, inducing similar to 10 SEs per explant with 52% induction frequency. On the other hand, the combination of 0.5 mg/l of IAA and 1 mg/l of TIBA produced significantly fewer (similar to 3.6 SEs) and abnormal (enlarged, oblong, jar and cup-shaped) SEs per explant with 24% induction frequency in comparison to that in the IAA alone. The explants treated with IAA-TIBA exhibited a delayed response along with the formation of abnormal SEs. Our study revealed that IAA induces high-frequency SE formation when used singly, but the frequency gradually declines when IAA was coupled with increasing levels of TIBA. Eventually, our findings bring new insights into the roles of auxin and its polar transport in somatic embryogenesis of D. trojana

Risk-taking, delay discounting, and time perspective in adolescent gamblers: an experimental study

Previous research has demonstrated that adult pathological gamblers (compared to controls) show risk-proneness, foreshortened time horizon, and preference for immediate rewards. No study has ever examined the interplay of these factors in adolescent gambling. A total of 104 adolescents took part in the research. Two equal-number groups of adolescent non-problem and problem gamblers, defined using the South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA), were administered the Balloon Analogue Risk Task (BART), the Consideration of Future Consequences (CFC-14) Scale, and the Monetary Choice Questionnaire (MCQ). Adolescent problem gamblers were found to be more risk-prone, more oriented to the present, and to discount delay rewards more steeply than adolescent non-problem gamblers. Results of logistic regression analysis revealed that BART, MCQ, and CFC scores predicted gambling severity. These novel finding provides the first evidence of an association among problematic gambling, high risk-taking proneness, steep delay discounting, and foreshortened time horizon among adolescents. It may be that excessive gambling induces shortsighted behaviors that, in turn, facilitate gambling involvement

Blunted endogenous opioid release following an oral amphetamine challenge in pathological gamblers

Pathological gambling is a psychiatric disorder and the first recognized behavioral addiction, with similarities to substance use disorders but without the confounding effects of drug-related brain changes. Pathophysiology within the opioid receptor system is increasingly recognized in substance dependence, with higher mu-opioid receptor (MOR) availability reported in alcohol, cocaine and opiate addiction. Impulsivity, a risk factor across the addictions, has also been found to be associated with higher MOR availability. The aim of this study was to characterize baseline MOR availability and endogenous opioid release in pathological gamblers (PG) using [(11)C]carfentanil PET with an oral amphetamine challenge. Fourteen PG and 15 healthy volunteers (HV) underwent two [(11)C]carfentanil PET scans, before and after an oral administration of 0.5 mg/kg of d-amphetamine. The change in [(11)C]carfentanil binding between baseline and post-amphetamine scans (ΔBPND) was assessed in 10 regions of interest (ROI). MOR availability did not differ between PG and HV groups. As seen previously, oral amphetamine challenge led to significant reductions in [(11)C]carfentanil BPND in 8/10 ROI in HV. PG demonstrated significant blunting of opioid release compared with HV. PG also showed blunted amphetamine-induced euphoria and alertness compared with HV. Exploratory analysis revealed that impulsivity positively correlated with caudate baseline BPND in PG only. This study provides the first evidence of blunted endogenous opioid release in PG. Our findings are consistent with growing evidence that dysregulation of endogenous opioids may have an important role in the pathophysiology of addictions