Laryngeal cancer in Colorado

Previous studies of laryngeal cancer have shown a decrease in the male-to-female ratio and that the sex ratio in glottic tumors is higher than that for other laryngeal sites. The purpose of this study was to characterize and identify changes in the demographics, laryngeal site predilection, geographic distribution, trends in tumor stage at diagnosis, and surgical caseload distribution in Colorado. The Colorado Central Cancer Registry for the years 1979 to 1990 was reviewed for cases of laryngeal cancer. The data were analyzed using chi-square and gradient-in-proportions methods. One-thousand two-hundred sixty-five (1265) cases were identified with a male-to-female ratio of 4.3:1. There was a significant trend of an increasing proportion of cases attributable to women. Glottic carcinoma accounted for 50.1% of cases, with a male-to-female ratio of 7.6:1. The Denver metropolitan area accounted for 57% of all cases, which was not disproportionate to the population. From 1981 to 1990 there was a significant decrease in the proportion of stage I cases and an increase in stage II cases. The teaching hospitals associated with the University of Colorado were responsible for performing 44.5% of all surgery for laryngeal cancer. The results indicate that laryngeal cancer in Colorado shares similar epidemiologic characteristics to those reported in other studies. Of most concern is the increasing proportion of women with laryngeal cancer and the decrease in cases diagnosed at stage I.     

Sex differences in mortality after traumatic brain injury, Colorado 1994-1998

Primary objective: The purpose of this study was to assess the relationship between sex and traumatic brain injury (TBI) mortality.

Methods and procedures: A total of 20 465 persons with TBI were identified from a Colorado population-based surveillance system for 1994-1998. Case fatality ratios were calculated to identify sex differences for selected risk factors. Unconditional logistic regression was used to determine the relationship between TBI mortality and sex controlling for risk factors.

Main outcomes and results: Adjusting for age, race, metropolitan residence and penetrating injury, the estimated odds of TBI mortality for males compared to females was 1.21 (95% CI 1.10, 1.34) for pre-hospital fatalities and 1.19 (95% CI 1.05, 1.37) for hospital fatalities.

Conclusion: Results indicate differences in TBI mortality comparing males and females. Future studies are warranted to identify if behaviour and physiological responses are associated with TBI outcomes among males and females.     

Description of a sauropod dinosaur braincase from the Late Cretaceous Rio Colorado Subgroup, Patagonia

The fossil record of cranial material from titanosaurid sauropods is very poor and no complete skull has been described so far. Here we describe a new braincase (MUCPv-334) that was recovered from reddish sandstones of the Rio Colorado Subgroup (Late Cretaceous) of the region of Bajo del A?elo, approximately 20 km north of the town A?elo (Neuquén Province, Argentina). This specimen is attributed to the Titanosauridae based on the ventrally projected basipterygoid processes, a common condition shared by other titanosaurids. The robustness of MUCPv-334 together with an unusually expanded crista prootica and the presence of an anterior prolongation of the parasphenoid reaching the basal tubera were not reported in other members of the Titanosauridae, indicating a larger diversity in the braincase morphology of this sauropod clade than previously thought.     

Reduced risk of IDDM among breast-fed children. The Colorado IDDM Registry

The hypothesis that breast-feeding can provide protection against the development of insulin-dependent diabetes mellitus (IDDM) and would, therefore, be less common among subjects with IDDM was tested with a retrospective design. Cases (n = 268) were selected from the Colorado IDDM Registry and the Barbara Davis Center for Childhood Diabetes (Denver, CO). Two control groups were recruited, one from physicians' practices throughout Colorado (n = 291) and the second through random-digit dialing from the Denver area (n = 188). Cases were less likely to have been breast-fed than controls after adjustment for birth year, maternal age, maternal education, family income, race, and sex [adjusted odds ratio (OR) = 0.70; 95% confidence interval (CI) = 0.50-0.97]. This finding was consistent for both control groups and by birth-year intervals. A greater decrease in risk of IDDM was seen among subjects who had been breast-fed to an older age (for breast-feeding duration of greater than or equal to 12 mo, adjusted OR = 0.54, 95% CI = 0.27-1.08). The amount of IDDM that might be explained by breast-feeding habits (population percentage attributable risk) ranged from 2 to 26%, varying according to the breast-feeding prevalence reported in other studies. Replication of this work in different populations, controlled for the strong secular trends in breast-feeding habits, is critical before the hypothesis of protection is accepted.