Executive clock drawing correlates with performance-based functional status in people with combat-related mild traumatic brain injury and comorbid posttraumatic stress disorder.

Executive Clock Drawing Tasks (CLOX parts 1 and 2) can predict functional impairment. This study determined the correlation between CLOX and other psychometric screening instruments with the Structured Assessment of Independent Living Skills (SAILS)-defined performance-based functional status in people with combat-related mild traumatic brain injury (TBI) and comorbid posttraumatic stress disorder (PTSD). We hypothesized that CLOX would correlate significantly with functional performance. This prospective, cross-sectional study design determined the correlation between a structured neuropsychological battery and functional status assessment. We calculated Pearson correlation coefficients between neuropsychological instruments and functional status scores. We entered neuropsychological measures correlating p < 0.1 with functional status into a linear regression model to determine independent contributions. Fifteen Operation Iraqi Freedom veterans participated. Only CLOX1 correlated significantly with functional competency and efficiency. Only mean CLOX1 scores were significantly lower in those scoring below the median for SAILS competency and in those scoring above the median for SAILS efficiency. CLOX1 contributed significant variance to functional status independent of mood or anxiety symptoms and was not affected by age or time since injury. Executive dysfunction per the brief, easily administered CLOX1 is sensitive to functional status following combat-related mild TBI, independent of PTSD anxiety with or without depression.

Modification by N-acetyltransferase 1 genotype on the association between dietary heterocyclic amines and colon cancer in a multiethnic study.

OBJECTIVE: Colorectal cancer incidence is greater among African Americans, compared to whites in the U.S., and may be due in part to differences in diet, genetic variation at metabolic loci, and/or the joint effect of diet and genetic susceptibility. We examined whether our previously reported associations between meat-derived heterocyclic amine (HCA) intake and colon cancer were modified by N-acetyltransferase 1 (NAT1) or 2 (NAT2) genotypes and whether there were differences by race. METHODS: In a population-based, case-control study of colon cancer, exposure to HCAs was assessed using a food-frequency questionnaire with a meat-cooking and doneness module, among African Americans (217 cases and 315 controls) and whites (290 cases and 534 controls). RESULTS: There was no association with NAT1*10 versus NAT1-non*10 genotypes for colon cancer. Among whites, there was a positive association for NAT2-"rapid/intermediate" genotype [odds ratio (OR)=1.4; 95% confidence interval (CI)=1.0, 1.8], compared to the NAT2-"slow" that was not observed among African Americans. Colon cancer associations with HCA intake were modified by NAT1, but not NAT2, regardless of race. However, the "at-risk" NAT1 genotype differed by race. For example, among African Americans, the positive association with 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP) was confined to those with NAT1*10 genotype (OR=1.8; 95% CI=1.0, 3.3; P for interaction=0.02, comparing highest to lowest intake), but among whites, an association with 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was confined to those with NAT1-non*10 genotype (OR=1.9; 95% CI=1.1, 3.1; P for interaction=0.03). CONCLUSIONS: Our data indicate modification by NAT1 for HCA and colon cancer associations, regardless of race. Although the at-risk NAT1 genotype differs by race, the magnitude of the individual HCA-related associations in both race groups are similar. Therefore, our data do not support the hypothesis that NAT1 by HCA interactions contribute to differences in colorectal cancer incidence between African Americans and whites.