New potential-treatment options in brain injury due to acute carbon monoxide poisoning in future

Serum NSE and S100B protein levels for evaluating the impaired consciousness in patients with acute carbon monoxide poisoning

The aim of this study was to investigate the associations between the levels of neuron-specific enolase (NSE) and S100B protein and coma duration, and evaluate the optimal cut-off values for prediction coma duration ≥ 72 hours in patients with acute carbon monoxide poisoning (ACOP).A total of 60 patients with ACOP were divided into 3 following groups according to their status of consciousness and coma duration at admission: Awake group [Glasgow Coma Scale score (GCS score) ≥ 13 points], Coma < 72 hours group (GCS score < 13 points and coma duration < 72 h), and Coma ≥ 72 hours group (GCS score < 13 points and coma duration ≥ 72 h). The levels of serum NSE and S100B protein were measured after admission.There were significant differences in GCS score, carbon monoxide (CO) exposure time, NSE, and S100B levels between the Coma ≥ 72 h group and the Awake group, and between the Coma < 72 h group and the Awake group. Significant differences in GCS score, NSE, and S100B levels were also found between Coma ≥ 72 h group and Coma < 72 h group. Correlation analysis showed that NSE and S100B were positively correlated (rs = 0.590, P < .01); NSE and S100B were negatively correlated with GCS score (rs = -0.583, rs = -0.590, respectively, both P < .01). The areas under the curve (AUCs) of NSE, S100B, and GCS score to predict the coma duration ≥ 72 hours were 0.754, 0.791, and 0.785, respectively. Pairwise comparisons did not show differences among the 3 groups (all P > .05). The sensitivity and specificity of NSE prediction with a cut-off value of 13 μg/L were 80% and 64%, respectively, and those of S100B prediction with a cut-off value of 0.43 μg/L were 70% and 88%, respectively.The NSE and S100B protein levels were significantly correlated with the degree of impaired consciousness and had the same clinical value in predicting coma duration of ≥ 72 hours in patients with ACOP.

Determination of netrin-1 levels and its relationship with neurotoxicity in carbon monoxide poisoning

OBJECTIVE

The aim of the study was to assess netrin-1 levels in carbon monoxide (CO) poisoning to determine its relationship with poisoning severity and neurotoxicity.

METHODS

This is a cross-sectional prospective study. The patients older than 18 years with CO poisoning were included. The patients were categorized into two groups on the basis of neurological involvement. Both the patient and the control groups were sampled for netrin-1 at 0th hour, and the patient group only was sampled for netrin-1 at 4th hour.

RESULTS

A total of 84 patients and 50 healthy controls were enrolled. The median 0th hour netrin-1 level of the patient group (765.1 pg/mL (619.8-983.1) was significantly higher than the control group (484 pg/mL (376-1031.6)) ( p < 0.001). There was also a significant difference between the 0th hour and 4th hour netrin-1 (888.9 pg/mL (700.3-1175.5)) levels in the patient group ( p < 0.001).There was no significant statistical difference between patients with and without neurological involvement ( p = 0.62) and between those who underwent hyperbaric oxygen therapy (HBOT) and those who did not ( p = 0.76) with respect to 4th hour netrin-1 levels.

CONCLUSION

The significantly higher netrin-1 levels in patients with CO poisoning, suggests that netrin-1 is elevated as a stress marker. Although there is no significant difference in netrin-1 levels in patients with neurological impairment in CO poisonings, netrin-1 may show subclinically neurological effects. Hence, we believe that netrin-1 cannot be used as a marker of poisoning severity.

Cardioprotective effects of insulin on carbon monoxide-induced toxicity in male rats

Carbon monoxide (CO) poisoning is a significant cause of death especially in developing countries. The current study investigated cardioprotective effects of insulin in CO-poisoned rats. Male rats were exposed to 3000 ppm CO for 1 h. Insulin (100 and 120 U/kg intraperitoneally) was immediately administered after CO exposure and on the next 4 days, on a daily basis (a total of 5 doses). On day 5, animals were euthanized, and the hearts were harvested for Western blotting and histopathological studies. The electrocardiograms (ECG) were recorded postexposure to CO and after the completion of insulin treatment period. Histopathological evaluations showed reduction of myocardial necrosis in insulin-treated animals compared to controls. BAX/BCL2 ratio, as a proapoptotic index, was significantly reduced in treatment groups ( p < 0.01). The ECG findings showed no differences among groups; also, compared to control animals, myocardial Akt levels were not markedly affected by insulin. The current study showed that insulin significantly reduces myocardial necrotic and apoptotic indices in CO-poisoned rats.