Docosahexaenoic Acid Promotes Axon Outgrowth by Translational Regulation of Tau and Collapsin Response Mediator Protein 2 Expression.

n-3 PUFAs are essential for neuronal development and brain function. However, the molecular mechanisms underlying their biological effects remain unclear. Here we examined the mechanistic action of docosahexaenoic acid (DHA), the most abundant n-3 polyunsaturated fatty acids in the brain. We found that DHA treatment of cortical neurons resulted in enhanced axon outgrowth that was due to increased axon elongation rates. DHA-mediated axon outgrowth was accompanied by the translational up-regulation of Tau and collapsin response mediator protein 2 (CRMP2), two important axon-related proteins, and the activation of Akt and p70 S6 kinase. Consistent with these findings, rapamycin, a potent inhibitor of mammalian target of rapamycin (mTOR), prevented DHA-mediated axon outgrowth and up-regulation of Tau and CRMP2. In addition, DHA-dependent activation of the Akt-mTOR-S6K pathway enhanced 5'-terminal oligopyrimidine tract-dependent translation of Tau and CRMP2. Therefore, our results revealed an important role for the Akt-mTOR-S6K pathway in DHA-mediated neuronal development.

Predictors for delayed encephalopathy following acute carbon monoxide poisoning.

BACKGROUND: In Japan, many carbon monoxide (CO) poisoning cases are transported to emergency settings, making treatment and prognostic assessment an urgent task. However, there is currently no reliable means to predict whether "delayed neuropsychiatric sequelae (DNS)" will develop after acute CO poisoning. This study is intended to find out risk factors for the development of DNS and to characterize the clinical course following the development of DNS in acute CO poisoning cases. METHODS: This is a retrospective cohort study of 79 consecutive patients treated at a single institution for CO poisoning. This study included 79 cases of acute CO poisoning admitted to our emergency department after attempted suicide, who were divided into two groups consisting of 13 cases who developed DNS and 66 cases who did not. The two groups were compared and analyzed in terms of clinical symptoms, laboratory findings, etc. RESULTS: Predictors for the development of DNS following acute CO poisoning included: serious consciousness disturbance at emergency admission; head CT findings indicating hypoxic encephalopathy; hematology findings including high creatine kinase, creatine kinase-MB and lactate dehydrogenase levels; and low Global Assessment Scale scores. The clinical course of the DNS-developing cases was characterized by prolonged hospital stay and a larger number of hyperbaric oxygen (HBO) therapy sessions. CONCLUSION: In patients with the characteristics identified in this study, administration of HBO therapy should be proactively considered after informing their family, at initial stage, of the risk of developing DNS, and at least 5 weeks' follow-up to watch for the development of DNS is considered necessary.

Characteristics of suicide attempts in patients diagnosed with schizophrenia in comparison with depression: a study of emergency room visit cases in Japan.

We worked on characterizing suicide attempts in patients with schizophrenia in comparison with mood disorders. This study population comprised 260 patients with F2 disorders (ICD-10), i.e., "schizophrenic group" and 705 patients with F3 disorders, i.e., "depressive group" who presented at the psychiatric emergency department of our hospital for 8 years. They were compared in three age groups: young (≤24 years), middle-aged (25-44 years), and elderly (≥45 years). Multivariate logistic regression analysis identified factors associated with the seriousness of the suicide attempt method. The schizophrenic group (≥25 years) had a younger mean age and higher prevalences of "within-1-year suicide attempts" and "past suicide attempts" than the depressive group. The Schizophrenic group tended to use serious methods, such as "jumping from high places," "throwing oneself in front of an oncoming train," and "burning oneself," in their suicide attempts, with "hallucination-delusion" accounting for an overwhelmingly large percentage of suicide attempt motives, irrespective of the age group. In the elderly group, the ratio of "no-housemate" patients was high. In all age groups, jobless individuals were prevalent, and the schizophrenic group had lower LCU (Life Change Unit) scores than did the depressive group. The middle-aged cases of schizophrenic group had higher BPRS (Brief Psychiatric Rating Scale) scores and lower GAS (Global Assessment Scale) scores. Regarding factors influencing the seriousness of the methods, a history of within-1-year suicide attempts increased the method seriousness in the schizophrenic group. Years of education correlated with the method seriousness in the schizophrenic group. Low scores of overall health on the GAS increased the method seriousness in both groups.