The role of nitric oxide in radiation damage.

This study investigated the role of nitric oxide in radiation-induced damage by examining changes in mouse serum nitrate concentrations after irradiation. In addition, the contribution of S-2-aminoethylisothiourea 2HBr (AET) to the mechanisms of radiation damage protection was also clarified. The serum nitrate concentration increased as soon as 1.5 h after irradiation, and after 2.5 to 3.0 h the concentrations were significantly higher compared with normal levels. Normal levels were re-established after 12 h. Post-irradiation serum nitrate concentrations increased dose-dependently with irradiation dose (19.6-31.5 Gy). AET suppressed increases in the serum nitrate concentration following irradiation while 2-mercaptoethylamine HCl (MEA) did not. AET has an inhibitory effect on inducible nitric oxide synthase (iNOS); therefore, the increase in nitric oxide after irradiation may be produced by iNOS. Combined administration of irradiation and lipopolysaccharide (LPS) induced a significant increase in serum nitrate concentration, and a significant decrease in survival rate, compared with irradiation alone. The administration of AET or aminoguanidine increased survival rate following irradiation. In contrast to findings after LPS administration, IL-1beta and IFN-gamma were not determined in serum following irradiation. Existing iNOS is activated by irradiation, and nitric oxide production appears to increase without iNOS induction. Thus, the irradiation-induced increase in nitric oxide may be related to lethal injury.

The reliability and validity of the Oppositional Defiant Behavior Inventory.

OBJECTIVE: The aim of this study was to develop an evaluation scale for use as a supplementary tool for the diagnosis of oppositional defiant disorder (ODD). METHOD: The subjects were 98 Japanese children (91 males and 7 females), aged 6-15 years, diagnosed with attention deficit/hyperactivity disorder (ADHD) or ODD. Internal consistency, test-retest reliability, concurrent validity and divergent validity of the oppositional defiant behavior inventory (ODBI), an evaluation scale of oppositional defiant tendency, were examined. RESULTS: Cronbach's alpha coefficient of the ODBI was 0.925. The correlation coefficient between the test and the retest was 0.820 (p < 0.0001). Both the ODBI scores (test and retest) were correlated with the number of items that matched the ODD diagnostic criteria of DSM-IV (r = 0.660, 0.659, p < 0.001), and with the ODD-scale of Disruptive Behavior Disorders Rating Scale (r = 0.725, 0.654, p < 0.001). Compared with the ADHD group or controls, the ADHD and ODD group showed a significantly higher ODBI score at p < 0.0001. CONCLUSION: The concurrent use of this scale with clinical examination is expected to increase the accuracy of the diagnosis of ODD.