Toxicity of hair dyes in human keratinocytes Effects of Basic Yellow 57 in combination with Resorcinol and Hydrogen Peroxide

Background. In the United States and Europe, more than 30% of women over 18 years and approximately 10% of men over 40 years are using hair colouring products. Previous studies have shown that low concentrations of the semi-permanent hair dye Basic Yellow 57 (BY57) lead to toxicity in human keratinocytes. The aim of this study is to investigate the DNA damaging effects of BY57 in combination with other (oxidizing) components, such as hydrogen peroxide (a bleach component) and resorcinol (a colour coupler) in human keratinocyte (HaCaT) cells. Furthermore, another aim of the present study is to evaluate the potential DNA damaging mechanisms caused by these hair dye components. Methods. The HaCaT cells were exposed to different concentrations BY57 (0-100 µg/ml), hydrogen peroxide (0-100 µM), resorcinol (0-100 µg/ml) and to the possible combinations of these components. Diphenyleneiodonium (DPI; 10 and 50 µg/ml) and hydroxyurea (HU; 10 mM) were added to the keratinocytes to evaluate the potential DNA damaging mechanisms. DPI was applied as an NADPH oxidase inhibitor and HU functions as an DNA polymerase inhibitor. In the present study, the tested concentrations are based on the proportion of the hair dye components as present in commercially available hair dye products. In order to detect potential DNA fragmentation after treating the cells with the different hair dye components, the single cell gel electrophoresis (comet) assay was used. Results. Treatment of the HaCaT cells with hydrogen peroxide (100 µM) and Basic Yellow 57 (100 µg/ml) lead to a significant induction of DNA fragmentation in human keratinocytes. The combination of BY57 together with hydrogen peroxide and resorcinol lead to a significant induction in DNA damage. However, this induction was approximately equal to the DNA damaging effects caused by hydrogen peroxide only. Furthermore, the addition of DPI lead to an unexpected induction of DNA fragmentation. Conclusion. The present results showed that the exposure of human keratinocytes to Basic Yellow 57, hydrogen peroxide and the combination treatments of the hair dye components containing hydrogen peroxide lead to an induction of DNA fragmentation. However, the possible working mechanisms of DNA damaging effects caused by BY57 remains unclear. The DNA damaging effects of DPI could suggest an inhibition of the DNA repair system via the inhibition of NADPH oxidase. Since this effect is not confirmed by the results of the DNA repair inhibitor (HU), no conclusion could be drawn from these findings. To elucidate the possible DNA damaging mechanisms of BY57 on human keratinocytes, further research is needed

Identification of TUB as a novel candidate gene influencing body weight in humans

Previously, we identified a locus on 11p influencing obesity in families with type 2 diabetes. Based on mouse studies, we selected TUB as a functional candidate gene and performed association studies to determine whether this controls obesity. We analyzed the genotypes of 13 single nucleotide polymorphisms (SNPs) around TUB in 492 unrelated type 2 diabetic patients with known BMI values. One SNP (rs1528133) was found to have a significant effect on BMI (1.54 kg/m(2), P = 0.006). This association was confirmed in a population enriched for type 2 diabetes, using 750 individuals who were not selected for type 2 diabetes. Two SNPs in linkage disequilibrium with rs1528133 and mapping to the 3' end of TUB, rs2272382, and rs2272383 also affected BMI by 1.3 kg/m2 (P = 0.016 and P = 0.010, respectively). Combined analysis confirmed this association (P = 0.005 and P = 0.002, respectively). Moreover, comparing 349 obese subjects (BMI >30 kg/m(2)) from the combined cohort with 289 normal subjects (BMI <25 kg/m(2)) revealed that the protective alleles have a lower frequency in obese subjects (odds ratio 1.32 [95% CI 1.04-1.67], P = 0.022). Altogether, data from the tubby mouse as well as these data suggest that TUB could be an important factor in controlling the central regulation of body weight in humans

Towards a high-precision measurement of the antiproton magnetic moment

The recent observation of single spins flips with a single proton in a Penning trap opens the way to measure the proton magnetic moment with high precision. Based on this success, which has been achieved with our apparatus at the University of Mainz, we demonstrated recently the first application of the so called double Penning-trap method with a single proton. This is a major step towards a measurement of the proton magnetic moment with ppb precision. To apply this method to a single trapped antiproton our collaboration is currently setting up a companion experiment at the antiproton decelerator of CERN. This effort is recognized as the Baryon Antibaryon Symmetry Experiment (BASE). A comparison of both magnetic moment values will provide a stringent test of CPT invariance with baryons.Comment: Submitted to LEAP 2013 conference proceeding

Markers of inflammation and coagulation indicate a prothrombotic state in HIV-infected patients with long-term use of antiretroviral therapy with or without abacavir

Background: Abacavir (ABC) treatment has been associated with an increased incidence of myocardial infarction. The pathophysiological mechanism is unknown. In this study markers of inflammation and coagulation in HIV-infected patients using antiretroviral therapy with or without ABC were examined to pinpoint a pathogenic mechanism. Given the important role of high sensitivity C-reactive protein (hsCRP) levels in predicting cardiovascular risk, patient groups were also analyzed according to hsCRP levels.Method

Promoting occupational health through gamification and e-coaching: A 5-month user engagement study

Social gamification systems have shown potential for promoting healthy lifestyles, but applying them to occupational settings faces unique design challenges. While occupational settings offer natural communities for social interaction, fairness issues due to heterogeneous personal goals and privacy concerns increase the difficulty of designing engaging games. We explored a two-level game-design, where the first level related to achieving personal goals and the second level was a privacy-protected social competition to maximize goal compliance among colleagues. The solution was strengthened by employing occupational physicians who personalized users’ goals and coached them remotely. The design was evaluated in a 5-month study with 53 employees from a Dutch university. Results suggested that the application helped half of the participants to improve their lifestyles, and most appreciated the role of the physician in goal-setting. However, long-term user engagement was undermined by the scalability-motivated design choice of one-way communication between employees and their physician. Implications for social gamification design in occupational health are discussed

Partner notification for reduction of HIV-1 transmission and related costs among men who have sex with men: A mathematical modeling study

Background Earlier antiretroviral treatment initiation prevents new HIV infections. A key problem in HIV prevention and care is the high number of patients diagnosed late, as these undiagnosed patients can continue forward HIV transmission. We modeled the impact on the Dutch menwho-have-sex-with-men (MSM) HIV epidemic and cost-effectiveness of an existing partner notification process for earlier identification of HIV-infected individuals to reduce HIV transmission. Methods Reduction in new infections and cost-effectiveness ratios were obtained for the use of partner notification to identify 5% of all new diagnoses (Scenario 1) and 20% of all new diagnoses (Scenario 2), versus no partner notification. Costs and quality adjusted life years (QALYs) were assigned to each disease state and calculated over 5 year increments for a20 year period. Results Partner notification is predicted to avert 18-69 infections (interquartile range [IQR] 13-24; 51-93) over the course of 5 years countrywide to 221-830 (IQR 140-299; 530-1,127) over 20 years for Scenario 1 and 2 respectively. Partner notification was considered cost-effective in the short term, with increasing cost-effectiveness over time: from €41,476 -€41, 736 (IQR €40,529-€42,147; €40,791-€42,397) to €5,773 -€5,887 (€5,134-€7,196; €5,411-€6,552) per QAL