Human brain tumors and exposure to metal and non-metal elements: a case-control study.

BACKGROUND: Primary brain tumors are among the most deadly of all cancers, with a 1-year survival rate of 52%. Certain elements, such as nickel, cadmium, chromium, arsenic, and beryllium, are established carcinogens in other organs. Silicon and titanium are suspected carcinogens and other elements are known to promote or inhibit the rate of tumor growth. Knowledge about the carcinogenicity of these elements in the brain is limited. In this study, we investigated the potential role of these elements as risk factors for human brain tumors. METHODS: In a case-control study, we assessed brain biopsies from 12 patients with various types of primary brain tumors and in tumor-free brain tissue from 6 autopsy cases. We used energy-dispersive X-ray analysis (EDX) to determine if there were significant differences in the concentration of the study elements in tumors and in control brains. RESULTS: In a bivariate analysis, a statistically significant association was observed between the presence of brain tumors and the concentrations of silicon (p = 0.01), magnesium (p = 0.01), and calcium (p = 0.03). Zinc was also associated with a borderline significance (p = 0.05). No association was observed for nickel (p = 0.74). Although the magnitude of the observed association was estimated using multiple logistic regression analyses, the relative risk estimates were imprecise because of insufficient sample size. Further research using a larger sample size is needed to elucidate the role of these elements in human brain carcinogenesis.

Omeprazole-Mg 20.6 mg is superior to lansoprazole 15 mg for control of gastric acid: a comparison of over-the-counter doses of proton pump inhibitors.

BACKGROUND: Over-the-counter (OTC) proton pump inhibitors (PPIs) relieve heartburn by decreasing the production of gastric acid, but may not do so with equal effectiveness. It is important for healthcare professionals to compare the ability of OTC PPIs to control gastric acid when recommending them for patients with frequent heartburn. AIM: To compare the effects of omeprazole-Mg 20.6 mg and lansoprazole 15 mg (OTC doses in the US) on 24-h steady state gastric acid suppression. METHODS: This single-centre, randomized, double-blind clinical study compared the steady-state gastric acid control of omeprazole-Mg 20.6 mg vs. lansoprazole 15 mg, dosed before breakfast. Volunteers were enrolled in a 3-period, cross-over design (ABB, BAA) with 24-h gastric pH monitoring on dosing day 5. The primary efficacy variable was the percentage time intragastric pH was >4.0 over 24 h on day 5 of dosing. RESULTS: Forty subjects were enrolled; all completed the study. The mean (SE) percentage time pH was >4.0 was 45.7% (3.45%) for omeprazole-Mg 20.6 mg and 36.8% (3.45%) for lansoprazole 15 mg, an absolute difference of 8.9% (P < 0.0001), and a relative difference of 24.2%. Both drugs were well tolerated. CONCLUSION: Omeprazole-Mg 20.6 mg provided a statistically significantly (P < 0.0001) greater acid control than lansoprazole 15 mg.

A randomized clinical trial comparing a novel 5.3% hydrogen peroxide whitening strip to 10%, 15%, and 20% carbamide peroxide tray-based bleaching systems.

A randomized and controlled, parallel-group clinical trial compared the whitening benefits of a novel 5.3% hydrogen peroxide bleaching strip to 10%, 15%, and 20% carbamide peroxide tray-based bleaching systems. A total of 36 healthy adults were randomized to a 14-day regimen in which both arches were whitened for 1 hour per day in the whitening-strip group or 2 hours per day in the tray groups. Efficacy was measured objectively using digital images of the anterior teeth at baseline and after 14 days of treatment. Overall tooth color (L*a*b*) was derived from individual pixel values, and then mean levels of delta b*, delta L*, and composite color (delta E*) were compared using analysis of covariance. After 14 days of treatment, all groups experienced a greater than 1-unit mean improvement in delta b*, delta L*, and delta E* relative to baseline. For the primary study variable, reduction of yellow (delta b*) outcomes after 14 hours of using the experimental strip were comparable to those observed with the 10% tray group after 28 hours of use. These two treatment groups did not differ statistically with respect to any of the color measurements used in this study. For the tray groups, there was a reasonable dose relationship for the primary end point, delta b*, with the 15% and 20% tray groups averaging 17% and 68% improvements in yellow, respectively, over the 10% group. Except for the 20% carbamide peroxide system, where sensitivity was relatively common, all test products were well tolerated. In this first comparative evaluation vs marketed controls, use of the whitening strips twice daily for 14 days yielded a highly significant improvement in tooth color vs baseline.

Impact of demographic, behavioral, and dental care utilization parameters on tooth color and personal satisfaction.

A cross-sectional survey across broad age ranges was conducted to evaluate demographic, behavioral, and treatment parameters that impact tooth color and its perception. The sample included 180 US adults and teenagers, with a comparable representation of males and females in 6 different age strata, ranging from 13 to 64 years. Tooth color (L*a*b*) was measured on the maxillary central incisors using a spectrophotometer, and first-person satisfaction with tooth color was assessed using a five-point qualitative scale. Demographic, behavioral, and oral care parameters were modeled using multiple regression analysis. After adjusting for other explanatory variables, age, gender, coffee/tea consumption, and dental care all significantly affected yellowing (b*) and brightness (L*). Dental-visit frequency was the only factor that significantly predicted self-satisfaction with tooth color, explaining just 3% of the overall variability. First-person dissatisfaction with tooth color was common and found in most demographic and behavioral cohorts. Although age contributed to objectively measured tooth discoloration, personal satisfaction with tooth color was age-independent. These results suggest that the need or demand for esthetic dentistry may be broad-based and transcend stereotypical perceptions.