To investigate the carcinogenic effect of environmental aflatoxin exposure, 56 cases of hepatocellular carcinoma (HCC) diagnosed between 1991 and 1995 were identified and individually matched by age, sex, residence and date of recruitment to 220 healthy controls from the same large cohort in Taiwan. Blood samples were analyzed for hepatitis B and C viral markers and for aflatoxin-albumin adducts; urine was tested for aflatoxin metabolites. We obtained information about sociodemographic characteristics, habitual alcohol drinking, cigarette smoking and diet in a structured interview. Hepatitis B virus surface antigen (HBsAg) carriers had a significantly increased risk for HCC. After adjustment for HBsAg serostatus, the matched odds ratio (ORm) was significantly elevated for subjects with high levels of urinary aflatoxin metabolites. When stratified into tertiles, a dose-response relationship with HCC was observed. The ORm for detectable aflatoxin-albumin adducts was not significant after adjustment for HBsAg serostatus. HBsAg-seropositive subjects with high aflatoxin exposure had a higher risk than subjects with high aflatoxin exposure only or HBsAg seropositivity only. In male HBsAg-seropositive subjects, adjusted ORs were 2.8 (95% confidence interval [CI] = 0.9-9.1) for detectable compared with non-detectable aflatoxin-albumin adducts and 5.5 (CI = 1.3-23.4) for high compared with low urinary aflatoxin metabolite levels. Our results suggest that environmental aflatoxin exposure may enhance the hepatic carcinogenic potential of hepatitis B virus. A large-scale study will be needed to evaluate the effect of aflatoxin exposure on HBsAg non-carriers.

No abstract

No abstract

Occupant injury in automobile rear-end collisions is becoming one of the most costly and aggravating traffic safety problems. Designing seat and head restraints to help limit injury associated with rear-end impact can become more efficient by using new mathematical modeling techniques. Using the facet surface modeling technique in MADYMO a model is developed that captures the interaction between occupants and seat/head restraints with a high degree of geometric accuracy while maintaining efficient computer run times. One such model is validated using a prototype seat/head restraint and the TRID (TNO Rear Impact Dummy), both using facet surface techniques. From this model a study is done to compare the results of the TRID model and the results from a Hybrid III model with the results from a Human neck model. This study is performed in several different head restraint positions.