Beneficial effect of the oxygen free radical scavenger amifostine (WR-2721) on spinal cord ischemia/reperfusion injury in rabbits

<p>Abstract</p> <p>Background</p> <p>Paraplegia is the most devastating complication of thoracic or thoraco-abdominal aortic surgery. During these operations, an ischemia-reperfusion process is inevitable and the produced radical oxygen species cause severe oxidative stress for the spinal cord. In this study we examined the influence of Amifostine, a triphosphate free oxygen scavenger, on oxidative stress of spinal cord ischemia-reperfusion in rabbits.</p> <p>Methods</p> <p>Eighteen male, New Zealand white rabbits were anesthetized and spinal cord ischemia was induced by temporary occlusion of the descending thoracic aorta by a coronary artery balloon catheter, advanced through the femoral artery. The animals were randomly divided in 3 groups. Group I functioned as control. In group II the descending aorta was occluded for 30 minutes and then reperfused for 75 min. In group III, 500 mg Amifostine was infused into the distal aorta during the second half-time of ischemia period. At the end of reperfusion all animals were sacrificed and spinal cord specimens were examined for superoxide radicals by an ultra sensitive fluorescent assay.</p> <p>Results</p> <p>Superoxide radical levels ranged, in group I between 1.52 and 1.76 (1.64 ± 0.10), in group II between 1.96 and 2.50 (2.10 ± 0.23), and in group III (amifostine) between 1.21 and 1.60 (1.40 ± 0.19) (p = 0.00), showing a decrease of 43% in the Group of Amifostine. A lipid peroxidation marker measurement ranged, in group I between 0.278 and 0.305 (0.296 ± 0.013), in group II between 0.427 and 0.497 (0.463 ± 0.025), and in group III (amifostine) between 0.343 and 0.357 (0.350 ± 0.007) (p < 0.00), showing a decrease of 38% after Amifostine administration.</p> <p>Conclusion</p> <p>By direct and indirect methods of measuring the oxidative stress of spinal cord after ischemia/reperfusion, it is suggested that intra-aortic Amifostine infusion during spinal cord ischemia phase, significantly attenuated the spinal cord oxidative injury in rabbits.</p

In SituMethodology for Studying State Driver Stress: A Between-Subjects Design Replication

Previous studies of driver stress have utilized in-vehicle in situ questionnaires to measure driver stress during the actual commute. These studies demonstrated several important findings, but all adopted a repeated-measures research design where each participant was exposed to counterbalanced high and low congestion conditions. This approach reduced between-subjects variability but increased the possibility of demand characteristics. The current study replicated the findings of the in situ methodology using a between-subjects research design. State stress was greater in heavy traffic. Time urgency, lack of perceived control, and trait susceptibility to perceiving driving as stressful contributed to higher levels of state driver stress. No gender differences in state driver stress were found. Implications of the results and future research directions are discussed

Personality Predictors of Driver Vengeance

The purpose of this study was to identify personality and individual difference measures related to driver vengeance, as measured by the Driver Vengeance Questionnaire (DVQ; Wiesenthal, Hennessy, & Gibson, 2000). There were 170 undergraduate students who completed paper-and-pencil questionnaires including the DVQ and measures of narcissism, impulsivity, and trait driver stress. A hierarchical linear regression predicting DVQ score revealed that being male (β = .25), narcissism (β = .19), and trait driver stress (β = .41) were significantly associated with vengeance. Impulsivity was significant in the third block of the regression but was not a significant predictor of vengeance in the final block. Interactions between gender and the individual difference measures were not significant. The final model accounted for 34% of the variance. Implications of the results and directions for future research are discussed

Anger-provoking events in driving diaries: A content analysis

A previously validated coding scheme of offensive driver behaviour was used to content analyse driving diary entries. A new perceived causation coding scheme was also developed to identify victims' perceptions of why events occurred. Inter-rater reliability of the behaviour coding scheme was very good (kappa = .81). The most frequently reported driver behaviours were weaving and cutting, which was included in 33% of all diary entries, followed by slow driving (20%), speeding (13%), perceived hostile driver displays (13%), and tailgating (11%). These results were contrasted with those of the previous applications of the coding scheme. Assessed independently across all diary entries, inter-rater reliability of the coding of three causation categories was within an acceptable range (kappa = .51, .41, .67 for retaliation, time urgency, and negligence, respectively). When applied exclusively to the critical diary entries identified by each participant as the most negative and upsetting, the reliability improved greatly (kappa = .60, .80, and .81). The most frequently reported source of perceived causation was negligence, involved in 15% of all diary entries and 41% of critical events, followed by time urgency (14% of all entries and 29% of critical events) and retaliation (9% of all entries and 11% of critical events). Future research applications of the content coding systems and implications of the findings for driver safety are discussed

Driver anger on the information superhighway: A content analysis of online complaints of offensive driver behaviour

In recent years, several websites have been developed allowing drivers to post their complaints about other motorists online. These websites allow drivers to describe the nature of the offensive behaviour and to identify the offending motorist by vehicle type, colour, and license plate number. Some websites also ask drivers to list the location where the event took place and the exact date and time of the offence. The current study was a content analysis of complaints posted to RoadRagers.com between 1999 and 2007 (N=5624). The purpose of the study was to: (1) assess the research value of this novel data source; (2) demonstrate the value of content analysis to the study of driver behaviour; (3) further validate an existing coding scheme; (4) determine whether this new data source would replicate previous research findings regarding the most frequent types of driver complaints and temporal distribution of these reports; (5) provide recommendations for improved driver training and public safety initiatives based on these data. A coding scheme that was originally developed for an assessment of complaints submitted to the Ontario Provincial Police (OPP) (Wickens et al., 2005) was revised to accommodate the new dataset. The inter-rater reliability of the revised coding scheme as applied to the website complaints was very good (kappa=.85). The most frequently reported improper driver behaviours were cutting/weaving, speeding, perceived displays of hostility, and tailgating. Reports were most frequent on weekdays and during the morning and afternoon rush hour. The current study replicated several findings from the analysis of reports to the OPP, but possible differences in the sample and data collection method also produced some differences in findings. The value of content analysis to driver behaviour research and of driver complaint websites as a data source was demonstrated. Implications for driver safety initiatives and future research will be discussed

Mind–Matter Interactions and the Frontal Lobes of the Brain: A Novel Neurobiological Model of Psi Inhibition

Context Despite a large literature on psi, which encompasses a range of experiences including putative telepathy (mind–mind connections), clairvoyance (perceiving distant objects or events), precognition (perceiving future events), and mind–matter interactions, there has been insufficient focus on the brain in relation to this controversial phenomenon. In contrast, our research is based on a novel neurobiological model suggesting that frontal brain systems act as a filter to inhibit psi and that the inhibitory mechanisms may relate to self-awareness. Objective To identify frontal brain regions that may inhibit psi. Design We used mind–matter interactions to study psi in two participants with frontal lobe damage. The experimental task was to influence numerical output of a Random Event Generator translated into movement of an arrow on a computer screen to the right or left. Brain MRI was analyzed to determine frontal volume loss. Results The primary area of lesion overlap between the participants was in the left medial middle frontal region, an area related to self-awareness, and involved Brodmann areas 9, 10, and 32. Both participants showed a significant effect in moving the arrow to the right, i.e., contralateral to the side of primary lesion overlap. Effect sizes were much larger compared to normal participants. Conclusions The medial frontal lobes may act as a biological filter to inhibit psi through mechanisms related to self-awareness. Neurobiological studies with a focus on the brain may open new avenues of research on psi and may significantly advance the state of this poorly understood field