The effect of different atmosphere absolute hyperbaric oxygen on the expression of extracellular histones after traumatic brain injury in rats

By observing the dynamic changes of extracellular histones H1, H2A, H4, and NF-κB expression in brain tissues after brain injury in rats, we explore the association among the expression of extracellular histones H1, H2A, H4, and NF-κB following traumatic brain injury (TBI), as well as the effect of different atmospheres absolute hyperbaric oxygen (HBO) intervention on the expression and possible mechanisms. A total of 120 SD rats were randomly divided into 4 groups: Sham-operated (SH), TBI (traumatic brain injury) group, traumatic brain injury and hyperbaric oxygen treatment 1.6ATA (TBI + HBO1) group, and traumatic brain injury and hyperbaric oxygen treatment2.2ATA (TBI + HBO2) group, with 30 rats in each group. The rats in each group were then randomly divided into five smaller time-specific sub-groups: 3 h, 6 h, 12 h, 24 h, and 48 h after surgery. TBI models were established, and the brain tissue around the lesion was taken at different time points. On the one hand,we detected the level of local histones H1, H2A, H4, and NF-κB by RT-PCR and Western Blot. On the other hand, we used immunohistochemical methods to detect the expression of NF-κB, while using the TUNEL method to observe the cell apoptosis in experimental groups after brain injury. Extracellular histones H1, H2A, H4, and NF-κB proteins were highly expressed at 3 h, then with a slight fluctuation, reached to peak at 48 h after the injury. HBO can affect the expression of histones H1, H2A, H4, and NF-κB. The decline of each indicator in the 1.6ATA group was significantly lower than that in the 2.2ATA group, especially within 6 h (P < 0. 05). In addition, NF-κB expression was consistent with the pathological changes of apoptosis in experimental groups. Hyperbaric oxygen therapy with relatively low pressure (1.6ATA) at the early stage can significantly inhibit the expression of extracellular histones H1, H2A, H4, and NF-κB around the lesion, reduce the apoptosis of nerve cells, and thus play an important role in alleviating secondary brain injury.

Performance Monitoring in Children Following Traumatic Brain Injury Compared to Typically Developing Children

Children with traumatic brain injury are reported to have deficits in performance monitoring, but the mechanisms underlying these deficits are not well understood. Four performance monitoring hypotheses were explored by comparing how 28 children with traumatic brain injury and 28 typically developing controls (matched by age and sex) performed on the stop-signal task. Control children slowed significantly more following incorrect than correct stop-signal trials, fitting the error monitoring hypothesis. In contrast, the traumatic brain injury group showed no performance monitoring difference with trial types, but significant group differences did not emerge, suggesting that children with traumatic brain injury may not perform the same way as controls.

Preliminary Standardization of the Cognitive Estimation Test

A modification of the Cognitive Estimation Test (CET) by Shallice and Evans was developed to assist in the scoring and interpretation of this measure of problem solving. Two studies were presented. In Study 1, the modified CET that required numeric responses was administered to 164 employed adults. Deviation scores were derived from percentiles from mean performance of this sample. Total deviation scores were highest for the least educated group. Study 2 found CET deviation scores to be significantly higher for a severe traumatic brain injury group relative to a sample of medical outpatients. The normative and clinical data presented are meant to serve as a starting point for further validation of this new measure.